[go: up one dir, main page]

WO2014194570A1 - 从窑法磷酸工艺的出窑烟气中水化吸磷及回收氟的方法 - Google Patents

从窑法磷酸工艺的出窑烟气中水化吸磷及回收氟的方法 Download PDF

Info

Publication number
WO2014194570A1
WO2014194570A1 PCT/CN2013/081225 CN2013081225W WO2014194570A1 WO 2014194570 A1 WO2014194570 A1 WO 2014194570A1 CN 2013081225 W CN2013081225 W CN 2013081225W WO 2014194570 A1 WO2014194570 A1 WO 2014194570A1
Authority
WO
WIPO (PCT)
Prior art keywords
phosphoric acid
tower
acid
flue gas
fluorosilicic
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/CN2013/081225
Other languages
English (en)
French (fr)
Inventor
侯拥和
魏世发
魏琛娟
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
SICHUAN KO CHANG TECHNOLOGY Co Ltd
Original Assignee
SICHUAN KO CHANG TECHNOLOGY Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by SICHUAN KO CHANG TECHNOLOGY Co Ltd filed Critical SICHUAN KO CHANG TECHNOLOGY Co Ltd
Priority to RU2015144714A priority Critical patent/RU2663032C2/ru
Publication of WO2014194570A1 publication Critical patent/WO2014194570A1/zh
Priority to US14/958,914 priority patent/US10023463B2/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B25/00—Phosphorus; Compounds thereof
    • C01B25/16—Oxyacids of phosphorus; Salts thereof
    • C01B25/18—Phosphoric acid
    • C01B25/20—Preparation from elemental phosphorus or phosphoric anhydride
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B25/00—Phosphorus; Compounds thereof
    • C01B25/16—Oxyacids of phosphorus; Salts thereof
    • C01B25/18—Phosphoric acid
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D1/00—Evaporating
    • B01D1/16—Evaporating by spraying
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/46—Removing components of defined structure
    • B01D53/68—Halogens or halogen compounds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/20—Halogens or halogen compounds
    • B01D2257/202—Single element halogens
    • B01D2257/2027—Fluorine
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/20—Halogens or halogen compounds
    • B01D2257/206—Organic halogen compounds
    • B01D2257/2066—Fluorine
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/55—Compounds of silicon, phosphorus, germanium or arsenic
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/02—Other waste gases
    • B01D2258/0283—Flue gases
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/151—Reduction of greenhouse gas [GHG] emissions, e.g. CO2

Definitions

  • the invention relates to a process for preparing phosphoric acid from flue gas containing P 2 0 5 and fluorine and recovering fluorine-containing substances, in particular to hydration absorption in a kiln flue gas from a kiln process phosphoric acid process (KPA)
  • KPA phosphoric acid process
  • wet process phosphoric acid that is, the phosphate ore is decomposed by sulfuric acid to obtain dilute phosphoric acid and solid waste residue (referred to as phosphogypsum) mainly composed of CaS0 4 ⁇ ⁇ 3 ⁇ 40, and the dilute phosphoric acid is concentrated to obtain wet-process phosphoric acid containing about 54% of phosphoric acid.
  • the main disadvantages of this process are as follows: First, a large amount of sulfuric acid is consumed; second, the waste slag phosphogypsum cannot be effectively utilized, and the entrained sulfuric acid, phosphoric acid and soluble fluoride are all dissolved in water, and are naturally washed by rainwater, which is easy to wash. Serious pollution to the environment; Third, the product phosphoric acid has a high impurity content, generally only used to produce fertilizer; Fourth, in order to ensure the economical efficiency of the product, high-grade phosphate rock must be used.
  • the product yellow phosphorus is obtained, and the exhaust gas containing CO is ignited and burned at the outlet of the chimney, and is discharged into the atmosphere; the obtained heating is heated to about 80 ° C, and it is changed into a liquid phase, which is generated in the hydration tower and the introduced air.
  • the oxidative combustion reaction is carried out to obtain phosphoric anhydride P 2 0 5 , which is then absorbed by water to obtain phosphoric acid.
  • thermal process phosphoric acid consumes a lot of electric energy; Second, the gas separated from P 4 after being discharged from the submerged arc furnace is also entrained with a large amount of fluoride (presented by SiF ⁇ P HF) and a small amount of unprecipitated gas P. 4 , this will cause serious pollution to the atmospheric environment; Third, the gas containing a large amount of CO is directly burned and emptied, and energy is wasted; Fourth, in order to ensure the economical efficiency of production, high-grade phosphate ore is also required.
  • the method is to finely grind phosphate rock, silica and carbonaceous reducing agent (coke powder or pulverized coal) to 50% ⁇ 85%-325 mesh, add 1% bentonite ball, and dry preheat through chain dryer.
  • the pellets in the kiln reduction to control the maximum temperature of the solids is 1400 ° C ⁇ 1500 ° C, to adjust the pellet Ca0 / Si0 2 molar ratio of 0. 26 ⁇ 0.
  • the melting point of the pellet is higher than the carbothermal reduction temperature of the phosphate ore in the pellet, and the phosphorus is volatilized from the pellet in the form of phosphorus vapor, and then The central space of the kiln is oxidized into phosphorus pentoxide by the ventilating air, and the heat released by the oxidation is in turn supplied to the reduction reaction, and finally the kiln gas containing phosphorus pentoxide is hydrated and absorbed to obtain phosphoric acid.
  • the above-mentioned kiln phosphoric acid process idea shows a good industrial application prospect, because the principle is to use the carbothermal reduction of phosphate rock to form a gas, transfer the phosphorus in the phosphate ore to the gas phase of the rotary kiln, and utilize the gas.
  • the principle of solid separation makes the phosphorus and the remaining solid matter in the pellets separate well.
  • the P 4 gas transferred to the gas phase of the rotary kiln can react with the oxygen in the gas phase of the rotary kiln to generate P 2 0 5 , which is released.
  • the rotary kiln maintains the carbon-thermal reduction temperature of the phosphate rock, the primary energy source is used, and the combustible material produced by the carbothermal reduction of the phosphate rock and the CO can be subjected to a combustion exothermic reaction inside the rotary kiln, and is supplemented and supplied to maintain the carbon heat of the phosphate rock in the rotary kiln.
  • the energy required to reduce the temperature which is significantly reduced compared to the traditional thermal process phosphoric acid process.
  • Rotary kiln is the equipment whose kiln body runs at a certain speed (0.5 r/mir! ⁇ 3r/min). It has the advantage of continuously mechanically turning and mixing the solid materials sent into the kiln to ensure the solid materials in the kiln. The uniformity of heat is everywhere, but in turn the solid material in the kiln is also subject to the mechanical friction of the material movement. If the material strength is less than the mechanical friction, it will be easily destroyed.
  • the basic principle of the KPA process proposed by the US 0RC company is to finely grind phosphate rock, silica and carbonaceous reducing agent (coke powder or pulverized coal) to 50% ⁇ 85%-325 mesh to make pellets.
  • the material pellets used in the process are equipped with a reducing agent carbon, and the carbon undergoes a rapid oxidation reaction with oxygen in the air at a temperature of more than 350 ° C to be converted into C0 2 , if a conventional metallurgical industrial pellet is used on the grate machine.
  • high temperature consolidation 900 °C
  • the reduced carbon in the pellets is completely oxidized, and the reducing agent is lost in the rotary kiln pellets.
  • the pellets entering the kiln will be pulverized in large quantities due to the mechanical friction that can not withstand the movement of the ball in the rotary kiln.
  • Phosphate powder, silica powder and carbonaceous reducing agent which form pellets after pulverization will be separated, and the phosphate rock powder which is pulverized cannot be reduced due to intimate contact with the carbonaceous reducing agent. More seriously, once the phosphate rock is separated from the silica powder, its melting point will be drastically reduced to below 1250 °C.
  • This powdered phosphate rock passes through the high temperature reduction zone of the rotary kiln (the temperature of the layer is about 1300 °C). , all will change from the solid phase to the liquid phase, and then adhere to the rotary kiln lining to form the high temperature ring of the rotary kiln, hinder the normal movement of the material in the rotary kiln, and join Most of the material of the rotary kiln overflows from the rotary kiln at the feed end of the rotary kiln, and the high temperature reduction of phosphorus cannot be achieved, resulting in process failure. It can be seen that due to the inherent defects of the raw materials entering the kiln, the above-mentioned KPA technology has not been used for any industrialization, scale or commercial application.
  • the solid material zone in the lower part of the rotary kiln belongs to the reduction zone, and the upper part of the zone is the gas flow zone of the rotary kiln, which belongs to the oxidation zone, the feed ball.
  • the group is added from the end of the rotary kiln, and is discharged from the kiln head area of the rotary kiln by its own gravity and the frictional force of the rotary kiln.
  • the burner for burning the rotary kiln is installed in the rotary kiln head, and the combustion fumes generated by the kiln are
  • the tail fan is taken out, and the micro-negative pressure is maintained in the rotary kiln, and the air flow is opposite to the moving direction of the material. Since there is no mechanical isolation zone in the reduction zone (solid layer zone) of the rotary kiln and the oxidation zone (the gas flow zone above the solid layer of the rotary kiln), the ball exposed on the surface of the solid zone zone will be in the gas stream with the oxidation zone.
  • the white shell of 5 the thickness of the shell is generally 300 ⁇ m ⁇ 1000 ⁇ m, and the content of P 2 0 5 in the shell layer can be as high as 30% or more; this will cause the transfer ball to P 2 0 5 in the gas phase to not exceed 60%. , resulting in a yield of phosphate in P 205 is low,
  • the waste of mineral resources and the significant increase in the cost of phosphoric acid production have caused the above-mentioned KPA process to lose its commercial application and industrial promotion value.
  • Some researchers hope to isolate the reduction zone in the rotary kiln through the volatilized gas in the layer. Oxidation zones, but industrial tests conducted in rotary kiln with an inner diameter of 2 m have shown that the presence of P 2 0 5 -rich white shell on the pellet surface is still unavoidable.
  • phosphoric acid is produced according to the KPA process proposed by 0RC, which is still very difficult in large-scale industrial applications and practices.
  • Joseph A. Megy has proposed some improved technical methods for the KPA process (see US Pat. No. 7,910,080 B), which is to set the stop at the discharge end of the kiln head of the rotary kiln cylinder while maintaining the basic KPA process.
  • the material ring is used to increase the solid material filling rate of the rotary kiln.
  • by increasing the diameter of the rotary kiln to reduce the surface area-volume ratio of the material layer in the rotary kiln the probability of the material layer being exposed on the surface of the solid material layer is reduced.
  • the process also adds a portion of petroleum coke to the material entering the rotary kiln, in order to utilize the reducing gas generated by the volatilization of the volatiles in the petroleum coke to cover between the material layer and the oxidation zone of the rotary kiln.
  • the material pellets to be used are double-layer composite structure, and the inner layer is made of phosphate rock, silica (or lime, limestone, etc.) and carbonaceous reducing agent after being ground and mixed.
  • the outer layer is a layer of solid fuel containing more than 20% carbon on the inner layer pellet. The inner and outer layers of the pellet are added with a binder, and the pellet is dried and consolidated.
  • Pellet inner Ca0 / Si0 2 molar ratio may be less than 0.6 or greater than 6.5, the carbonaceous reducing agent is a reducing 1 ⁇ 3 times the theoretical amount of phosphate rock, the solid fuel pellet with an outer layer of the inner layer can amount
  • the mass of the pellet is 5% to 25%;
  • the binder added to the pellet and the outer layer may be asphalt, sodium humate, ammonium humate, water glass, sulfite pulp waste liquid, syrup, lignosulfonate 2% ⁇ 15% ( ⁇ ) ⁇
  • the pellet can be dried and consolidated, the consolidation temperature is 80 ° C ⁇ 600 ° C, and the consolidation time is 3 min ⁇ 120 min.
  • the above method proposed by the method uses a high temperature resistant wrapping material containing solid carbon on the pellet, and a binder is added during the wrapping so that the outer covering can adhere well to the inner pellet.
  • the double-layer composite pellets are dried and consolidated and sent to the rotary kiln.
  • the high temperature zone of the rotary kiln 300 ° C ⁇ 140 (about TC) can achieve the carbothermal reduction of phosphate ore.
  • the surface of the sphere is artificially coated with a coating layer containing a solid reducing agent (carbonaceous material), which can align its inner layer pellets with the gas oxidization zone containing 0 2 and P 2 0 5 in the upper part of the rotary kiln layer. Effective physical isolation.
  • the carbon in the coating layer can undergo a limited oxidation reaction with 0 2 in the oxidation zone (due to the time when the material ball is exposed on the surface of the rotary kiln layer in the industrial large rotary kiln) Shorter, less complete reaction, so that 0 2 can not be transferred to the inner pellet, ensuring that the reducing agent carbon in the inner pellet is not oxidized by the oxygen in the rotary kiln gas flow, so that P 2 0 5 in the phosphate rock the reduction process can be performed completely realized process P 2 0 5 in phosphate Reduction rate.
  • an upper kiln gas stream in the oxidation zone layers P 2 0 5 can not react with the carbon composite pellet surface layer and wrapping, thus preventing the formation of a phosphate or metaphosphate on the composite pellets
  • the salt compound eliminates the formation of P 2 0 5 white shell on the original KPA process sphere, ensuring that the process can obtain a higher P 2 O 5 yield.
  • the method is replaced by solid fuel or Partially replaced Gas or liquid fuel, which further reduces the production cost of phosphoric acid.
  • the concentration of P 2 0 5 in the kiln flue gas is relatively low, and the former flue gas volume of the same scale is 3 to 4 times that of the latter;
  • the kiln flue gas composition of the kiln method is complicated, fluorine, dust, 30 2 and other impurities. Therefore, if the conventional acid-recovering method of thermal phosphoric acid is still used, there are many problems: First, the amount of flue gas of the thermal phosphoric acid is small, and the flue gas flow rate of the corresponding equipment is low, if directly applied to the kiln process phosphoric acid process, The size of the equipment system can be quite large. The equipment system is not only complicated in structure, but also has high investment and operating costs.
  • the flue gas impurity content of the kiln method phosphoric acid is complicated, and the spray acid is more corrosive, and it is necessary to prevent acidity.
  • the clogging of equipment and pipelines by solid impurities requires further improvement of the acid collection process and equipment structure.
  • the kiln method phosphoric acid kiln flue gas also contains fluorine-containing substances harmful to human body (with SiF ⁇ P HF). Form exists), which needs to be recycled while avoiding environmental pollution.
  • the technical problem to be solved by the invention is to provide a kiln flue gas containing P 2 0 5 , SiF 4 , HF and dust in the kiln method, and to provide a simplified process flow, reasonable layout, low equipment investment cost and strong adaptability.
  • the high recovery rate of the valence element, the environmental protection of the exhaust gas, and the good recovery of the phosphorus and fluorine are good.
  • the method of hydration and absorption of P 2 0 5 from the kiln flue gas of the kiln process phosphoric acid process and the method of recovering fluorine.
  • the technical solution proposed by the present invention is a method for hydrating phosphorus in the kiln flue gas from the kiln phosphoric acid process, comprising the following steps:
  • the fluorine-containing substance in the kiln flue gas (existing in the form of SIF P HF) is difficult to be absorbed into the spray liquid in the hydration tower, and the residual flue gas in the hydration tower Exhausted through its flue gas outlet;
  • the phosphoric acid solution sprayed down in the hydration tower enters the acid circulation spray system through a liquid inlet, first flows into the acid cooler, and transfers the hot enthalpy portion in the phosphoric acid solution to the circulating cooling of the acid cooler.
  • the heat of the phosphoric acid solution is continuously transferred by the cooling water, and the circulating phosphoric acid solution flowing out from the outlet of the acid cooler is returned to the spraying device of the hydration tower through the circulation pump to continue the circulating spraying;
  • the flue gas discharged from the flue gas outlet passes through the phosphoric acid mist trapping tower and the defogging separation tower in turn, so that the phosphoric acid mist entrained in the flue gas is further captured, the phosphoric acid mist trapping tower and demisting
  • the dilute phosphoric acid solution formed after the separation tower captures the phosphoric acid mist maintains the string acid with the concentrated phosphoric acid solution in the hydration tower through a pipeline arrangement; the so-called string acid preferably means: the phosphoric acid mist trapping tower and the defogging separation tower are trapped
  • the concentrated dilute phosphoric acid solution is pumped to the hydration tower and mixed with the concentrated phosphoric acid solution in the hydration tower to maintain the acid concentration in the hydration tower acid circulation spray system; at the same time, the acid from the hydration tower In the liquid circulation spray system, a part of the concentrated phosphoric acid solution is extracted and clarified by a filtering device, and the clarified supernatant
  • the concentrated phosphoric acid solution in the acid circulation spray system will increase continuously, and the excess part will be filtered as a crude phosphoric acid product, and the crude phosphoric acid product will enter the subsequent phosphoric acid refining process;
  • the supporting online water supply device implements online hydration for the whole process, and the outlet flue gas of the defogging separation tower enters the subsequent fluorine recovery process.
  • the spraying device in the hydration tower comprises at least two spray layers located at different heights of the vat chamber, and at least two spray layers comprise a dilute phosphoric acid spray a shower layer and a concentrated phosphoric acid spray layer, the concentrated phosphoric acid spray layer is disposed above the dilute phosphoric acid spray layer;
  • the inlet pipe of the circulating phosphate spray layer is in communication with the acid liquid circulation spray system, the dilute phosphoric acid
  • the liquid inlet pipe of the spray layer is connected with the circulating conveying pipe of the dilute phosphoric acid solution in the phosphoric acid mist collecting tower to cause the dilute phosphoric acid solution in the phosphoric acid mist collecting tower to be acid-acidized into the hydration tower, and the acid liquid circulating spray
  • the system is additionally connected to the phosphoric acid mist trap by piping to cause the circulating phosphoric acid solution in the hydration column to be acidized into the phosphoric acid mist trap.
  • the acid cooler is a heat exchange plate in which a plurality of modified graphite tubes or stainless steel tubes are arranged in a stirring tank, and circulating cooling water is introduced into the tubes, and the acid is introduced into the stirring tank.
  • the phosphoric acid solution of the refrigerator forms forced convection heat transfer on the heat exchange plate; the kiln flue gas in the step (1) is exchanged with the circulating phosphoric acid solution circulating and sprayed, and the water cooling system in the hydration tower is cooled, the temperature Dropped to 75 ° C ⁇ 130 ° C ;
  • the concentration of the phosphoric acid solution sprayed in the hydration tower is 60% to 90%, and the temperature of the concentrated phosphoric acid solution in the hydration tower is controlled to be 50 ° C to 80 °. C, the spray liquid gas ratio in the hydration tower is controlled at lL/m 3 ⁇ 20 L/m 3 .
  • the phosphoric acid purification step includes a phosphoric acid purification tank for purifying the crude phosphoric acid product, and the activated carbon, diatomaceous earth, desulfurizing agent, and arsenic removal agent, activated carbon and diatom are added to the phosphoric acid purification tank.
  • the amount of the earth is controlled to be 0.1% to 2% of the mass of the crude phosphoric acid product to be refined; the desulfurizing agent is a soluble cerium salt, and the amount thereof is 1 to 2 times the theoretical amount (according to the chemical reaction formula); 5h ⁇ 2 ⁇
  • the arsenic acid is stirred in the phosphoric acid tank.
  • the reaction time is 0. 5h ⁇ 2h. After the stirred reaction product is pumped to the filtration system for filtration, the filtrate is the finished phosphoric acid.
  • the phosphoric acid mist trapping tower is a first-stage countercurrent washing tower, comprising a washing tube and a separating tank, and the flue gas discharged from the flue gas outlet of the hydrating tower enters the washing of the phosphoric acid mist collecting tower.
  • the circulating dilute phosphoric acid solution sprayed from the bottom to the top in the washing tube collides with the upstream and downward flue gas to establish a foaming zone, and the flue gas passes through the foaming zone and is continuously updated with a large area of dilute phosphoric acid solution liquid.
  • the gas and liquid enter the lower separation tank for gas-liquid separation, and the separation tank also serves as a circulating acid tank (recycle tank of dilute phosphoric acid solution), and most of the circulating dilute phosphoric acid solution falls into the bottom of the separation tank and is mostly sent back through the circulation pump.
  • TC dilute phosphoric acid solution
  • the mass concentration of the diluted phosphoric acid solution circulating in the phosphoric acid mist trapping tower is 10% to 50%;
  • the temperature of the dilute phosphoric acid solution Control 40 ° C ⁇ 70 ° C, acid mist capturing tower spray liquid-gas ratio is controlled at 3L / m 3 ⁇ 25L / m 3 .
  • the flue gas discharged from the flue gas outlet in the phosphoric acid mist collecting tower is further returned to the defogging separation tower for further gas-liquid separation, and the lower part of the defogging separation tower is designed to be similar to cyclone dust removal.
  • the phosphoric acid droplets are trapped in the structure, and the grown phosphoric acid droplets are collected from the flue gas by centrifugal force.
  • a screen demister is installed in the upper part of the defogging separation tower to increase the phosphoric acid that has not grown in the flue gas.
  • the mist is further captured;
  • the online water replenishing device is installed in the defogging separation tower and is located at a flue gas outlet position above the screen mist eliminator, which serves as a water supply device for the entire process system on the one hand and a cleaning device on the other hand
  • the phosphoric acid mist in the flue gas is further trapped and doubles as a flushing device for the screen mist eliminator.
  • the present invention also provides a method for hydrating phosphorus and recovering fluorine from a kiln flue gas of a kiln process phosphoric acid process, which is based on the above technical solutions, and further includes the following Step of fluorine recovery process:
  • First-stage fluorine absorption First, the fluorine-containing flue gas discharged from the defogging separation tower is sent to the fluorosilicic acid washing tube of the first-stage fluorine absorption tower, and the flue gas is from top to bottom and nozzle
  • the circulating fluorosilicic acid solution injected from bottom to top generates sufficient gas-liquid two-phase contact, and carries out mass transfer heat transfer and chemical reaction to form fluorosilicic acid, and the enthalpy in the flue gas circulates the fluorosilicic acid through adiabatic evaporation.
  • the moisture in the solution is partially transferred to the water vapor;
  • the first-stage fluorine absorption tower and the second-stage fluorine absorption tower are both fluidized counter-current washing towers, and the first-stage fluorine absorption tower is mainly composed of a fluorosilicic acid washing tube and a fluorosilicic acid separation tank, and an outlet of the fluorosilicate washing tube Connected to the middle of the fluorosilicic acid separation tank, the top of the fluorosilicic acid separation tank is provided with a flue gas outlet, and the bottom is provided with a fluorosilicic acid liquid outlet, and the fluorosilicic acid liquid outlet passes through a circulating conveying pipeline with a circulating pump and the fluorine The nozzles in the silicic acid washing tube are connected;
  • the secondary fluorine absorption tower is mainly composed of a secondary fluorosilicate washing tube and a secondary fluorosilicic acid separation tank, and the flue gas outlet of the first-stage fluorine absorption tower is connected to the secondary fluorosilicate washing tube through the pipeline, the secondary fluorine
  • the outlet of the silicic acid washing tube is connected to the middle of the secondary fluorosilicate separation tank, and the top of the secondary fluorosilicate separation tank is provided with a defoaming layer (the defoaming layer is periodically sprayed with a circulating fluorosilicic acid solution to keep the defoaming Effect) and flue gas outlet, the bottom is provided with a fluorosilicic acid liquid outlet, the fluorosilicic acid liquid outlet passes through a circulating conveying pipe of a circulating pump and a nozzle in the secondary fluorosilicate washing pipe and the fluorosilicic acid of the first-stage fluorine absorption tower
  • the separation tanks are connected to each other.
  • the circulating transport pipeline in the secondary fluorine absorption tower is further provided with a fluorosilicic acid cooler, and the circulating fluorosilicic acid solution entering the secondary fluorosilicate washing tube passes through the fluorine silicon. Cooling treatment of the acid cooler.
  • the first-order fluorine absorption uses a circulating fluorosilicic acid solution having a mass concentration of 8% to 25% (more preferably 10% to 20%), and the circulating fluorosilicic acid solution has a temperature of 25 ° C.
  • the spray liquid to gas ratio is controlled at 3L / m 3 ⁇ 25L / m 3 (more preferably 3L / m 3 ⁇ 6L / m 3 );
  • the circulating fluorosilicic acid solution has a mass concentration of 0.5% to 5%, and the circulating fluorosilicic acid solution has a temperature of 25 ° C to 60 ° C (more preferably 45 ° C to 60 ° C), and the spray liquid to gas ratio It is controlled at 3 L/m 3 to 25 L/m 3 (more preferably 3 L/m 3 to 6 L/m 3 ).
  • the flue gas outlet of the secondary fluorine absorption tower is further connected to a tail suction tower, the tail suction tower is a spray empty tower, and the top of the tail suction tower is provided with a flue gas outlet, the tower The inner upper part is provided with a spray layer, and the bottom is provided with an alkali absorption liquid tank.
  • the outlet of the alkali absorption liquid tank communicates with the spray layer in the tail suction tower through a circulating conveying pipe with a circulation pump, and controls the 11 value of the alkali absorption liquid.
  • the advantages of the present invention over the prior art are: (1) The method for hydrating and absorbing phosphorus of the invention greatly improves and optimizes the existing phosphoric acid plant and process, so that the structure of the whole device is more simplified, the process flow is more reasonable, and the adaptability is more;
  • the method for recovering fluorine of the present invention greatly improves and optimizes the existing equipment and process for recovering fluorine, so that the structure of the entire fluorine recovery equipment is more simplified, the process flow is more reasonable, and the hydration absorption can be better matched.
  • the phosphoric acid process route is required;
  • the hydration phosphorus absorption and fluorine recovery device of the invention greatly simplifies the system structure and reduces the investment, operation and maintenance cost of the device;
  • the simultaneous recovery of P 2 0 5 and fluorine in the kiln flue gas by the kiln process phosphoric acid process can be realized, and the effective cooperation of the hydration absorption phosphorus and the fluorine recovery process can be realized, thereby obtaining a higher value.
  • the main product phosphoric acid and by-product fluorosilicic acid make the raw material resources more fully utilized and improve the economic benefits of the kiln process phosphoric acid process;
  • the device of the invention can be completely applied to the direct production of phosphoric acid in low-grade phosphate rock, and can fully adapt to the characteristics of flue gas containing P 2 0 5 and fluorine (especially kiln process kiln gas) and the need for treatment, which is low for China
  • flue gas containing P 2 0 5 and fluorine especially kiln process kiln gas
  • the effective use of grade phosphate rock is of great significance.
  • FIG. 1 is a schematic structural view of a fluorine recovery apparatus according to a specific embodiment of the present invention.
  • FIG. 2 is a flow chart of a fluorine recovery process in a specific embodiment of the present invention.
  • FIG 3 is a schematic structural view of a process system in a specific embodiment of the present invention.
  • FIG. 4 is a schematic enlarged view showing the structure of a hydration tower of a phosphoric acid plant in an embodiment of the present invention.
  • Fig. 5 is a schematic enlarged view showing the structure of a phosphoric acid mist trapping tower of a phosphoric acid plant according to an embodiment of the present invention.
  • FIG. 6 is a flow chart of a hydration phosphorus absorption process in a specific embodiment of the present invention.
  • First-stage fluorine absorption tower 51, fluorosilicic acid washing tube; 52, fluorosilicic acid separation tank; 53, fluorosilicic acid liquid outlet; 54, fluorosilicic acid refining equipment; , secondary fluorine absorption tower; 61, secondary fluorosilicate washing tube; 62, secondary fluorosilicate separation tank; 63, fluorosilicic acid cooler; 7, tail suction tower; 8, fan.
  • the method for hydrating phosphorus and recovering fluorine in the kiln flue gas from the kiln phosphoric acid process of the present invention requires the following process system shown in FIG. 3, the process system includes a phosphoric acid system and Equipment for recycling fluorine.
  • the phosphoric acid production system used in this embodiment includes a hydration tower 1, an acid circulation spray system, a phosphoric acid mist trap tower 3, and a defogging separation tower 4.
  • the body of the hydration tower 1 is a spray empty tower, the lower part of the hydration tower 1 is provided with a flue gas inlet 11 for discharging kiln flue gas, and the top is provided with a flue gas outlet 12 after hydration absorption, above the flue gas inlet 11
  • the hydration tower 1 has a sprinkling device 13 in the cavity, and the liquid inlet 14 of the acid circulating sprinkler system is disposed at the bottom of the hydration tower 1, and the liquid outlet 15 of the acid circulating sprinkler system is connected to the shower
  • An acid reservoir 16 and a circulation pump 2 are also provided in the inlet pipe of the device 13, and in the acid circulation spray system.
  • the outer wall of the liquefaction tower 1 is covered with a water cooling system 17, and the cooling water in the water cooling system 17 is used in the way of going in and out.
  • an acid cooler 18 is disposed in the acid circulation spray system near the liquid inlet port 14; the outlet of the acid cooler 18 is connected to the inlet of the acid liquid storage tank 16, and the outlet of the acid liquid storage tank 16
  • the circulation pump 2 is connected to the inlet pipe of the shower device 13, thereby forming an acid circulation shower system.
  • the phosphoric acid mist trapping tower 3 is a fluidized countercurrent scrubbing tower, which is mainly composed of a washing pipe 31 and a separating tank 32.
  • the flue gas outlet 12 of the hydrating tower 1 communicates with the inlet of the washing pipe 31 through a pipe, and the washing pipe
  • the outlet of 31 is connected to the middle of the separation tank 32, the top of the separation tank 32 is provided with a flue gas outlet 12, and the bottom is provided with an acid outlet 33 which passes through a circulation conveying pipe of the circulation pump 2 and the inside of the washing pipe 31.
  • the nozzles 35 are in communication (see Fig. 5), and the separation tank 32 serves as an acid circulation tank for circulating the conveying pipe in the phosphoric acid mist collecting tower 3.
  • the spraying device 13 of the hydration tower 1 in this embodiment is provided with three spray layers at different heights of the liquefaction tower 1, and three
  • the spray layer comprises a dilute phosphoric acid spray layer 25 and two concentrated phosphoric acid spray layers 24 (see Figure 4), and two concentrated phosphoric acid spray layers 24 are disposed above the dilute phosphoric acid spray layer 25;
  • the liquid inlet pipe of the layer 24 is in communication with the acid circulating spray system of the hydration tower 1, and the inlet pipe of the dilute phosphoric acid spray layer 25 is connected to the circulating conveying pipe of the phosphoric acid mist collecting tower 3, so that the first realization is achieved.
  • the acid liquid in the phosphoric acid mist collecting tower 3 is sent to the hydration tower 1. Further, on the conveying pipe after circulating the pump 2 in the above-mentioned acid liquid circulating spray system, it is connected to the acid liquid inlet 34 of the phosphoric acid mist collecting tower 3 through a pipe.
  • the branch pipe is provided with a packing filtering device 22, and the acid inlet of the packing filtering device 22 is connected to the acid circulating spraying system through the branch pipe, and the filtrate outlet of the packing filtering device 22 is Divided into three ways, all the way to the acid liquid inlet 34 of the phosphoric acid mist collecting tower 3, one way to the external phosphoric acid refining device 23, the other way to the acid liquid storage tank 16; the bottom outlet of the packing filter device 22 passes The pipe is connected to the feed port of the filter press device 21, and the overflow port of the filter press device 21 is passed through the pipe and the acid circulation spray system.
  • the acid liquid storage tank 16 is connected to fully realize the recovery and utilization of phosphoric acid, thereby ensuring high yield of phosphoric acid.
  • the underflow of the packing filter unit 22 is periodically pumped to the filter unit 21 for filtration to remove solids present in the acid circulating shower system.
  • the flue gas outlet 12 of the phosphoric acid mist collecting tower 3 is connected to the lower portion of the defogging separation tower 4 through a pipe, and the flue gas outlet 12 is disposed at the top of the defogging separation tower 4 to discharge the flue gas after hydration and phosphorus absorption.
  • the defogging separation tower 4 is provided with an in-line water rinsing device 41, and the water added by the inline water rinsing device 41 can simultaneously serve as hydration for the entire hydration absorption phosphoric acid process, and is gradually returned to the upstream phosphoramide trapping tower 3 through a pipeline.
  • the upper portion of the defogging separation tower 4 is provided with a screen mist eliminator 42, and the lower portion is designed as a phosphor droplet collecting structure similar to a cyclone.
  • the on-line water rinsing device 41 is installed above the screen demister 42.
  • the apparatus for recovering fluorine used in the present embodiment is as shown in Fig. 1, and includes a first-stage fluorine absorption tower 5 and a second-stage fluorine absorption tower 6. Both the first-stage fluorine absorption tower 5 and the second-stage fluorine absorption tower 6 employ a fluidized countercurrent scrubber.
  • the first-stage fluorine absorption tower 5 is mainly composed of a fluorosilicic acid washing tube 51 and a fluorosilicic acid separation tank 52, and the inlet of the fluorosilicic acid washing tube 51 is connected to the conveying pipe of the hydrated phosphorus-absorbing flue gas, and the fluorosilicic acid washing tube
  • the outlet of 51 is connected to the middle of the fluorosilicic acid separation tank 52, the top of the fluorosilicic acid separation tank 52 is provided with a flue gas outlet 12, the bottom is provided with a fluorosilicic acid liquid outlet 53, and the fluorosilicic acid liquid outlet 53 is passed through a belt circulation pump.
  • the circulating conveying pipe of 2 is in communication with the nozzle 35 in the fluorosilicate washing pipe 51, and the fluorosilicic acid separating tank 52 serves as an acid circulation tank of the circulating conveying pipe.
  • the structure of the secondary fluorine absorption tower 6 in this embodiment is similar to that of the first-stage fluorine absorption tower 5.
  • the secondary fluorine absorption tower 6 is mainly composed of a secondary fluorosilicate washing tube 61 and a secondary fluorosilicate separation tank 62.
  • the flue gas outlet 12 of the fluorine absorption tower 5 is connected to the inlet of the secondary fluorosilicate washing tube 61 through a pipe, and the outlet of the second-stage fluorosilicate washing tube 61 is connected to the middle of the second-stage fluorosilicic acid separation tank 62, the secondary fluorine
  • the top of the silicic acid separation tank 62 is provided with a flue gas outlet 12, and the bottom is provided with a fluorosilicic acid liquid outlet 53 which passes through a circulating conveying pipe of the circulating pump 2 and a secondary fluorosilicate washing pipe 61.
  • the nozzles 35 are in communication.
  • a fluorosilic acid cooler 63 is further disposed on the circulating conveying pipe of the secondary fluorine absorption tower 6.
  • the inlet of the fluorosilicic acid cooler 63 is connected to the circulation pump 2, and the outlet is divided into two paths, one way and two stages.
  • the nozzles 35 in the fluorosilicate washing tube 61 are in communication with each other, and the other is in communication with the spray layer at the top of the secondary fluorosilicate separating tank 62.
  • the secondary fluorosilicate separating tank 62 also serves as an acid circulating tank for the circulating conveying line.
  • the outlet of the circulation pump 2 of the secondary fluorine absorption tower 6 is also connected to the inlet of the fluorosilicic acid separation tank 52 of the primary fluorine absorption tower 5 through a branch pipe, whereby the fluorosilicic acid solution of the secondary fluorine absorption tower 6 can be removed.
  • the string is passed to the first-stage fluorine absorption tower 5.
  • the equipment for recovering fluorine in the present embodiment is finally connected with a tail suction tower 7, which is a spray empty tower, and the flue gas outlet 12 of the second-stage fluorine absorption tower 6 passes.
  • the pipe is in communication with the flue gas inlet 11 of the tail suction tower 7.
  • the top of the tail suction tower 7 is provided with a flue gas outlet 12, a spray layer is arranged on the upper side of the tower, and a sodium hydroxide absorption liquid tank is arranged at the bottom, and the sodium hydroxide absorption liquid tank outlet passes through the circulation conveying pipeline with the circulation pump 2 and
  • the spray layers in the tail suction tower 7 are connected to form an exhaust gas absorption circulating spray system.
  • the above-mentioned fluorosilicic acid liquid outlet 53 is additionally connected to an external fluorosilicic acid refining device 54 (or a fluoride salt processing device) through a pipe with a feed pump, and can pass through the filter press device 21 before entering the fluorosilicic acid refining device 54.
  • the filter press treatment is performed, and the overflow port of the filter press device 21 is connected to the fluorosilicic acid refining device 54 through a pipe.
  • the method for hydrating phosphorus and recovering fluorine in the kiln flue gas from the kiln process phosphoric acid process of the present embodiment specifically includes the following steps (see FIG. 2 and FIG. 3 for details). And Figure 6):
  • the flue gas containing P 2 0 5 and fluorine (special case is the kiln flue gas above 500 ° C in the KPA kiln process phosphoric acid process, P 2 0 5 content 80 g/Nm 3 ) is imported from the flue gas of the lower part of the hydration tower 1 11 into the tower, before the circulation pump 2 of the acid circulation spray system is turned on, so that the concentrated phosphoric acid solution in the hydration tower 1 is sprayed through the upper and middle two layers of concentrated phosphoric acid spray layer 24, the uppermost layer of concentrated phosphoric acid spray Part of the nozzle of layer 24 is sprayed obliquely downward to the inner wall of the tower, and the other nozzles are sprayed vertically downward.
  • fluorine special case is the kiln flue gas above 500 ° C in the KPA kiln process phosphoric acid process, P 2 0 5 content 80 g/Nm 3
  • the nozzles of the middle and lower spray layers are sprayed vertically downward, and the concentrated phosphoric acid solution sprayed and the P containing the tower are sprayed.
  • 205 and fluorine full contact countercurrently the flue gas, heat and mass transfer for generating the concentrated acid phosphate P 205 and the flue gas in the spray water chemical reaction to generate more than half of the phosphoric acid to be absorbed into the
  • the spray liquid, the rest of the phosphoric acid mist is kept in the gas phase, and the fluorine in the flue gas (such as SiF ⁇ P HF, etc.) is difficult to be absorbed into the spray liquid under concentrated phosphoric acid and higher temperature conditions;
  • By heat exchange with the lower temperature concentrated phosphoric acid solution sprayed in circulation and cooling of the water cooling system 17 in the hydration tower 1, Was lowered to 75 ° C ⁇ 130 ° C, a temperature cycle of concentrated phosphoric acid solution of the water column 1 were raised to 70 ° C ⁇ 95 ° C.
  • the mass concentration of the concentrated phosphoric acid solution sprayed in the spray can be selected from the range of 60% to 90% (in this embodiment, a phosphoric acid solution having a concentration of 70% to 85%), the hydration tower
  • the temperature of the inlet of the concentrated phosphoric acid solution is controlled to be 50 ° C to 80 ° C, and the spray liquid to gas ratio is controlled to be 3 L / m 3 to 20 L / m 3 .
  • more phosphorous mist is present in the form of a mist, which cannot be settled in the hydration tower 1, and is taken out of the hydration tower 1 along with the flue gas.
  • the hydration tower 1 has a dual function of cooling flue gas and hydration absorption of P 2 0 5 , wherein the main chemical reaction occurs as follows.
  • the concentrated phosphoric acid solution sprayed down in the hydration tower 1 finally enters the acid circulation spray system through the liquid inlet 14 and then flows into the acid cooler 18, and the structure of the acid cooler 18 is a stainless steel tube arranged in a stirring tank.
  • the heat exchanger plate is formed into a circulating cooling water, and the phosphoric acid solution entering the acid cooler 18 is forced to form a forced convection heat transfer on the heat exchange plate to improve the heat transfer efficiency and heat the concentrated phosphoric acid.
  • Partially transferred to the circulating cooling water of the acid cooler 18, the heat of the circulating concentrated phosphoric acid solution is continuously transferred by the cooling water.
  • the circulating acid flowing out from the outlet of the acid cooler 18 enters the acid liquid storage tank 16, and is again returned to the respective nozzles of the upper and middle two concentrated phosphoric acid spray layers 24 by the circulation pump 2 for circulating spraying.
  • the gas phase material i.e., flue gas
  • the gas phase material discharged from the flue gas outlet 12 at the top of the hydration tower 1 enters the washing tube 31 of the phosphoric acid mist collecting tower 3, which is a fluidized countercurrent washing tower, which is in the washing tube 31.
  • the dilute phosphoric acid solution is sprayed down and upward, and the dilute phosphoric acid solution forms a strong turbulent region in the gas-liquid interface region after colliding with the high-speed flue gas flow from the top to the bottom, and the fluid momentum After reaching equilibrium, a stable foam zone (foam column) is established at a certain height.
  • the flue gas passes through the foam zone and is in contact with a large surface of the continuously updated phosphoric acid solution liquid surface, and particle trapping, polymerization growth and heat generation occur in the foam zone. Transfer, most of the phosphoric acid mist entrained in the flue gas is transferred to the circulating dilute phosphoric acid solution.
  • the apparent flow velocity of the flue gas in the absorption zone is 10m/ s to 30m/s, and the liquid-gas ratio is 3L/m 3 to 25L/m 3 .
  • the flue gas is further cooled to 60 ° C to 75 ° C by adiabatic evaporation of the water in the dilute phosphoric acid solution.
  • the phosphorous mist trapping tower of the invention can greatly reduce the power head loss of the equipment and reduce the energy consumption of the acid collecting device under the same demisting effect.
  • the acid solution circulating in the phosphoric acid mist collecting tower 3 is a dilute phosphoric acid solution having a mass concentration of 10% to 50%, and the gas and liquid in the washing tube 31 enter the separation tank 32 in the lower portion of the column for gas-liquid separation, circulating acid. The liquid falls into the bottom of the separation tank 32.
  • the separation tank 32 of the tower also serves as a circulating acid tank, and the dilute phosphoric acid solution at the bottom is sent back to the washing tube 31 through the circulation pump 2 or the dilute phosphoric acid spray of the acid to the hydration tower 1 as needed. In layer 25.
  • the flue gas discharged from the flue gas outlet 12 in the phosphoric acid mist trap tower 3 is further introduced into the defogging separation tower 4 for further gas-liquid separation to further remove the phosphoric acid mist in the flue gas, and the lower portion of the defogging separation tower is designed Similar to the cyclone trapping structure 43 of the cyclone dust collector, the grown phosphoric acid droplets are collected from the flue gas by centrifugal force, and a screen demister 42 is installed in the upper part of the defogging separation tower, and the flue gas is Phosphorus droplets that have not yet grown up are further captured to ensure the direct yield of the device to P 2 0 5 ; the flue gas after the phosphating phosphorus removal by the defogging separation tower 4 is sent to the fluorine recovery equipment for fluorine recovery. deal with.
  • the P 2 0 5 in the flue gas needs to consume water, and in the process of cooling the flue gas, part of the water is evaporated from the sprayed acid solution, so the hydration absorption process needs to continuously replenish water, the process of this embodiment
  • the amount of water that needs to be replenished in the system is all replenished from the flue gas outlet 12 of the defogging separation tower 4, and the in-line water washing device 41 serves not only as a water replenishing device but also as a flushing device for the upper screen demisters of the defogging separation tower 4. .
  • the bottom liquid of the defogging separation tower 4 is returned to the phosphoric acid mist collecting tower 3 through the acid liquid inlet 34 of the phosphoric acid mist collecting tower 3, so the phosphoric acid mist is trapped.
  • the concentration of circulating acid in the tower 3 will gradually decrease.
  • the hydration tower 1 continuously absorbs P 2 0 5 in the flue gas, and the circulating acid concentration will gradually increase.
  • the hydration tower 1 and The circulating acid liquid system of the phosphoric acid mist trapping tower 3 needs to carry out string acid to maintain the stability of the respective circulating acid liquid concentrations, and the acid of the hydrating tower 1 string to the phosphoric acid mist collecting tower 3 is clarified and filtered in the packing filtering device 22.
  • the acid mist collecting tower 3 is introduced, and the acid from the phosphoric acid mist collecting tower 3 to the hydrating tower 1 is directly taken out from the outlet of the circulating pump 2 of the phosphoric acid mist collecting tower 3.
  • the hydrated phosphorus-absorbing flue gas is sent to the fluorosilicic acid washing tube 51 of the first-stage fluorine absorption tower 5, and most of the fluorine (mainly silicon tetrafluoride) in the flue gas is from the top to the bottom and the nozzle 35 is from the bottom.
  • the circulating fluorosilicic acid solution (mass concentration 10% ⁇ 20%) is sprayed with sufficient gas-liquid two-phase contact, and mass transfer heat transfer and chemical reaction are carried out. Most of the fluorine in the flue gas reacts with water.
  • the fluorosilicic acid is generated, and the heat enthalpy in the flue gas is mostly transferred to the circulating fluorosilicic acid solution by heat transfer; the method of circulating the fluorosilicic acid solution by the adiabatic evaporation of the water in the fluorosilicic acid solution and the heat transfer It is further cooled to 50 ° C ⁇ 7 (TC ; the main chemical reactions in this step are as follows:
  • 3SiF 4 +33 ⁇ 40 2H 2 SiF 6 + Si0 2 ⁇ 3 ⁇ 40.
  • the products finally obtained in the fluorosilicic acid washing tube 51 are all transferred to the fluorosilicic acid separation tank 52 for gas-liquid separation, and the separated gas passes through the flue gas outlet of the primary fluorine absorption tower 5 to enter the secondary fluorine absorption tower 6.
  • the separated liquid is retained in the fluorosilicic acid separation tank 52 and returned to the fluorosilicate washing tube 51 through the circulation conveying pipe with the circulation pump 2 to carry out the operation of the above step 4.
  • the flue gas entering the secondary fluorosilicate washing tube 61 (the remaining fluorine-containing substance, mainly silicon tetrafluoride) is a cyclic fluorosilicic acid solution sprayed from the top to the bottom and the nozzle 35 from the bottom up. (The mass concentration is 0.5% ⁇ 1. 5%) Full gas-liquid two-phase contact occurs, and mass transfer heat transfer and chemical reaction are carried out to form fluorosilicic acid, and the heat in the flue gas is transferred again through heat. Transfer to the circulating fluorosilicic acid solution; the temperature of the product treated in step 3 is further reduced to below 60 ° C; the chemical reaction mainly occurring in this step is the same as in step 4.
  • the products finally obtained in the secondary fluorosilicate washing tube 61 are all transferred to the secondary fluorosilicate separation tank 62 for gas-liquid separation, and the second fluorosilicic acid separation tank 62 is provided with a defogging unit at the top to remove the flue gas.
  • the entrained mist increases the absorption rate of F, and the defogging unit is sprayed by circulating the fluorosilicic acid solution through the top.
  • the separated gas passes through the flue gas outlet of the secondary fluorine absorption tower 6 and enters the subsequent tail suction tower 7 for treatment.
  • the separated liquid remains in the secondary fluorosilicate separation tank 62 and is sent back through the circulating conveying pipe with the circulation pump 2.
  • the operation of the above step 6 is performed in the secondary fluorosilicate washing tube 61, and the circulating conveying pipe is installed with a fluorosilicic acid cooler 63 to remove a part of the heat in the circulating fluorosilicic acid solution, so that the fluorine absorption reaction energy can be compared. It is carried out at a suitable temperature.
  • the circulating fluorosilicic acid solution entering the secondary fluorosilicate washing tube 61 is subjected to cooling treatment by a fluorosilicic acid cooler 63 (conventional cooling equipment); part of the excess circulating fluorosilicic acid solution can be directly discharged to the first-stage fluorine absorption tower The fluorosilicic acid separation tank 52 of 5.
  • the circulating fluorosilicic acid solution in the first-stage fluorine absorption tower 5 and the second-stage fluorine absorption tower 6 accumulates due to absorption of fluorine (mainly silicon tetrafluoride) in the flue gas, and the concentration of the fluorosilicic acid in the first-stage fluorine absorption tower 5 Concentrated by absorption of SiF ⁇ P HF in flue gas, secondary fluorine absorption
  • the excess circulating fluorosilicic acid solution in the receiving tower 6 is discharged into the primary fluorine absorption tower 5 to maintain a constant concentration, and the excess circulating fluorosilicic acid solution in the first-stage fluorine absorption tower 5 is pumped to the pressure filter through the feedstock.
  • the device 21 performs pressure filtration to remove solid materials such as silica gel, and the filtrate is purified into a fluorosilicic acid (concentration of about 12%) or processed into a fluoride salt product by a defluorosilicic acid refining process; the filter residue is silica gel, and after washing and removing impurities As a by-product.
  • the flue gas entering the subsequent tail suction tower 7 is in countercurrent contact with the downwardly sprayed NaOH solution during the upward movement of the tail suction tower 7, and the bottom absorption tank of the tail suction tower 7 passes through the circulation pump 2 and the various sprays in the tower.
  • the shower layer is connected to form a circulating spray system; in order to maintain the absorption capacity of the absorption liquid, the pH value of the absorption liquid is maintained at 8 or more, and it is necessary to continuously add a dilute NaOH solution, and the absorption liquid is added by the dilute NaOH solution and the flue gas P 2 0 5 , the absorption of fluorine and other impurities will accumulate, need to be continuously discharged for sewage treatment, the treated water can be reused to the raw material process of kiln process phosphoric acid; the remaining pollutants in the flue gas (P 2 0 5 , SiF 4 , dust, etc.) is absorbed by the spray liquid, and the flue gas is further washed and purified to meet the national discharge standard (the gas fluorine content is reduced to 9 mg/m 3 or less), and then discharged to the chimney through the induced draft fan.
  • the main chemical reactions occurring in this step are as follows.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Inorganic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Biomedical Technology (AREA)
  • Environmental & Geological Engineering (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Treating Waste Gases (AREA)

Abstract

本发明公开了一种从窑法磷酸工艺的出窑烟气中水化吸磷及回收氟的方法，包括以下步骤：先将含P2O5和氟的出窑烟气通入一水化塔内，此前开启与水化塔相连接的酸液循环喷淋系统，烟气与喷淋液进行传质传热，生成的磷酸大部分被吸收进喷淋液中，喷淋落下的磷酸溶液最后通过一进液口进入酸液循环喷淋系统中，从烟气出口排出的烟气再依次通过磷酸雾捕集塔和除雾分离塔，使出水化塔烟气中夹带的磷酸雾被进一步捕集，酸液循环喷淋系统中的浓磷酸溶液可进入磷酸精制工序；而除雾分离塔排出的含氟烟气则进入后续的氟回收工序。本发明具有流程简化、布局合理、设备投资成本低、适应性强、环保达标、磷氟同时回收效果好等优点。

Description

从窑法磷酸工艺的出窑烟气中水化吸磷及回收氟的方法
【技术领域】
本发明涉及一种从含 P205和氟的烟气中制取磷酸并回收含氟物质的工艺方法，尤其涉及 —种从窑法磷酸工艺 （KPA) 的出窑烟气中水化吸磷制取磷酸及回收氟的工艺方法。
【背景技术】
目前世界上工业生产磷酸的方法主要有两种。 （1 ) 湿法制磷酸： 即利用硫酸分解磷矿石 得到稀磷酸和以 CaS04 · η¾0为主体的固体废渣（简称磷石膏），将稀磷酸浓缩得到含磷酸 54% 左右的湿法磷酸。 这种工艺的主要缺点： 一是要耗用大量的硫酸； 二是废渣磷石膏无法得到 有效的利用， 其中夹带的硫酸、 磷酸和可溶性氟化物均溶于水， 自然堆放后被雨水冲刷， 容 易对环境造成严重污染； 三是产品磷酸的杂质含量较高， 一般只用于生产肥料； 四是为保证 产品的经济性， 必须使用高品位磷矿。 （2 ) 热法制磷酸： 即首先将将磷矿石、 硅石、 碳质固 体还原剂置于一台矿热电炉中， 用电短路形成电弧的能量， 将炉内温度加热到 1300°C以上， 将磷矿石中的磷以 形式还原出来， 同时碳质固体还原剂被转化为 C0， 将排出矿热炉的 P4 和 CO为主的气体用水洗涤降温， P4被冷却成固体与气相分离， 得到产品黄磷， 含 CO的废气 在烟囱出口点火燃烧后排入大气； 将得到的 加热到 80°C左右， 使其变为液相， 将其在水化 塔中与通入的空气发生氧化燃烧反应， 得到磷酸酐 P205， 再用水吸收得到磷酸。 热法制磷酸 的主要缺点： 一是要耗费大量的电能； 二是排出矿热炉后分离了 P4的气体还夹带有大量的氟 化物（以 SiF^P HF存在）和少量未沉淀的气体 P4， 这将对大气环境造成严重污染； 三是含大 量 CO的气体直接燃烧排空， 能源浪费很大； 四是为了保证生产的经济性， 同样需要使用高品 位磷矿石。
为了克服电能紧张、 硫铁矿资源不足和高品位磷矿石逐年减少对磷酸生产的影响， 八十 年代初美国 Occidental Research Corporation ( 0RC) 提出采用 KPA法， 即用回转窑生产 磷酸的方法（简称窑法磷酸工艺） （参见 Frederic Ledar and Won C. Park等， New Process for Technical-Grade Phosphoric Acid, Ind. Eng. Chem. Process Des. Devl985, 24, 688-697)， 并进行了 0. 84m (内） X 9. 14m回转窑中试装置的中间试验 （参见 US4389384号美国专利文 献）。 该方法是将磷矿石、 硅石和碳质还原剂（焦粉或煤粉）细磨到 50%〜85%— 325目， 配加 1%的膨润土造球， 经链式干燥机干燥预热后送入窑头燃烧天然气的回转窑中， 球团在窑内还 原， 控制最高固体温度为 1400°C〜1500°C， 调整球团 Ca0/Si02摩尔比为 0. 26〜0. 55， 使球团 熔点高于球团中磷矿石的碳热还原温度， 磷以磷蒸气的形式从球团中还原挥发出来， 然后在 窑的中部空间被通入的空气氧化成五氧化二磷， 氧化放出来的热反过来又供给还原反应， 最 后将含有五氧化二磷的窑气水化吸收即制得磷酸。
上述的窑法磷酸工艺思路显示了一种良好的工业应用前景， 因其原理是利用磷矿的碳热 还原形成 气体， 将磷矿石中的磷转移到回转窑的气相当中， 并利用气固分离原理使磷与料 球中的其余固体物质很好的进行分离， 转移到回转窑气相中的 P4气体可与回转窑气相中的氧 发生氧化放热反应生成 P205， 放出的热则供给料球中磷矿石的碳热还原 （吸热反应）， 最后将 出回转窑的含 P205的窑气水化吸收， 可获得洁净度远高于湿法磷酸的工业磷酸。 由于回转窑 维持磷矿碳热还原温度使用的是初级能源，同时磷矿碳热还原产生的可燃物质 与 CO在回转 窑内部即可进行燃烧放热反应， 补充提供给维持回转窑磷矿碳热还原温度所需能量， 这与传 统的热法制磷酸工艺相比， 其能耗得到大幅度降低。
然而， 我们的研究表明， 上述的窑法磷酸工艺在规模化的工业应用及实践中很难实现， 其主要缺陷在于：
1、 回转窑是窑体以一定速度（0. 5r/mir！〜 3r/min )运转的设备， 其优点是可以连续对送 入窑内的固体物料进行机械翻转、 混合， 保证窑内固体物料各处受热的均匀性， 但反过来窑 内固体物料亦须承受物料运动的机械摩擦力， 如果物料强度小于受到的机械摩擦力将很容易 被破坏。 美国 0RC公司提出的 KPA工艺基本原理是将磷矿石、 硅石和碳质还原剂 （焦粉或煤 粉） 细磨到 50%〜85%— 325 目后制成球团， 这三种物质必须紧密地共聚一体， 才能在混合物 中 Ca0/Si02摩尔比为 0. 26〜0. 55 的条件下， 实现混合物料在磷矿石的碳热还原温度下不熔 化， 同时， 磷矿的碳还原才能得以顺利进行。 但工艺使用的物料球团中配入了还原剂碳， 碳 在大于 350 °C温度下会与空气中的氧发生快速的氧化反应转变成 C02， 如果采用传统冶金工业 球团在链篦机上高温固结的方法 （ 900 °C )， 则球团中的还原碳会被全部氧化， 入回转窑球 团则流失了还原剂， 磷的碳热还原反应自然也无法进行， 导致工艺失败。 如果仅通过添加膨 润土作球团粘结剂在 300 °C以下进行干燥脱水， 则球团抗压强度仅为 10KN/个球左右， 落下强 度 1次 /米； 因为膨润土的作用机理主要是利用其物质结构中的层间水来调节球团干燥过程 中的水分释放速率， 提高球团在干燥过程中的爆裂温度， 其本身对提高球团强度并无显著作 用。 将这种球团送入回转窑后、 且在回转窑温度值达到 900 °C温度前， 由于承受不住回转窑 内料球运动所受到的机械摩擦力， 入窑的球团将大量粉化， 粉化后组成球团的磷矿粉、 硅石 粉和碳质还原剂等将分离， 粉化后的磷矿粉由于不能与碳质还原剂紧密接触， 将导致磷不能 被还原。 更为严重的是， 磷矿粉一旦与硅石粉分开， 其熔点将急剧降低到 1250 °C以下， 这种 粉状磷矿通过回转窑的高温还原区 （料层温度为 1300 °C左右） 时， 将全部由固相变成液相， 进而粘附在回转窑窑衬上形成回转窑的高温结圈， 阻碍物料在回转窑内的正常运动， 使加入 回转窑的大部分物料从回转窑加料端溢出回转窑， 无法实现磷的高温还原， 导致工艺失败。 可见， 由于入窑原料存在固有缺陷， 至今未见上述的 KPA技术进行过任何工业化、 规模化或 商业化的应用。
2、对于上述配碳磷矿球团的 KPA工艺而言， 在回转窑内料层下部的固体料层区属于还原 带， 料层上部则是回转窑的气流区， 属于氧化带， 进料球团从回转窑窑尾加入， 依靠其自身 重力和回转窑旋转的摩擦力从回转窑的窑头区排出， 回转窑燃烧燃料的烧嘴安装在回转窑窑 头， 产生的燃烧烟气则由窑尾的风机引出， 回转窑内维持微负压， 气流与物料的运动方向相 反。 由于在回转窑的还原带 （固体料层区） 和氧化带 （回转窑固体料层上部的气流区） 无机 械隔离区， 因此， 暴露在固体料层区表面的料球将与氧化带气流中的 、 （¾发生对流传质； 这一方面会使料球中的还原剂碳在料球被气流传热加热到磷矿石碳还原温度前被部分氧化 掉， 致使料球在回转窑还原带由于碳质还原剂的缺乏， 而得不到充分还原； 更为严重的是， 在回转窑高温区暴露于料层表面的料球， 会与窑气中已经还原生成的 P205发生进一步的化学 反应， 生成偏磷酸钙、 磷酸钙及其他的偏磷酸盐或磷酸盐， 进而导致已被还原到气相中的磷 又重新返回料球，并在料球表面形成一层富含 P205的白壳，壳层厚度一般在 300 μ m〜1000 μ m， 壳层中 P205含量可高达 30%以上； 这样会致使料球转移到气相中的 P205不超过 60%， 造成磷矿 中 P205的收率偏低， 进而造成矿产资源的浪费及磷酸生产成本的大幅度上升， 使上述的 KPA 工艺丧失商业应用和工业推广价值。 有研究人员寄望通过料层中挥发出的气体来隔离回转窑 中的还原带与氧化带， 但在内径 2m的回转窑中进行的工业试验表明， 球团表面出现富含 P205 的白壳现象仍是不可避免的。
鉴于上述提及的技术缺陷， 按照 0RC公司所提出的 KPA工艺来生产磷酸， 这在规模化的 工业应用及实践中还存在很大困难。
Joseph A. Megy对 KPA工艺提出过一些改进的技术方法 （参见 US7910080B号美国专利文 献）， 即在维持 KPA基本工艺方法不变的前提下， 通过在回转窑筒体的窑头泄料端设置挡料圈 以提高回转窑的固体物料填充率， 与此同时， 通过增大回转窑的直径以减少回转窑内料层的 表面积-体积比， 降低料层物料暴露在固体料层表面的几率， 以缩短料球中还原剂碳被回转窑 窑气中的 氧化的时间， 减少料球到达回转窑还原带前的还原剂碳的烧损， 同时减少回转窑 高温区中料球表面磷酸盐或偏磷酸盐的生成。 另外， 该工艺还通过在入回转窑的物料中加入 部分石油焦， 以希望利用石油焦中挥发分受热挥发产生的还原性气体， 使其覆盖在料层与回 转窑气流氧化区之间， 以进一步阻止回转窑气流中 、 P205与料球反应的几率， 以保证工艺的 正常进行。 然而， 提高回转窑的填充率将使料球在回转窑内承受更大的机械摩擦力， 进而将 造成料球在回转窑内更大比例的粉化， 形成更多的小于磷矿碳热还原温度的低熔点物质， 使 回转窑高温结圈更加迅速和严重， 从而更早造成工艺的失败。 而添加少量的石油焦产生的挥 发分不足以产生足够的气体， 难以在回转窑固体料层与回转窑内气流区之间形成有效的隔离 层， 若加入量过大， 则出回转窑物料中将夹带有大量的燃料， 这会导致在后续工艺的渣球冷 却机中， 剩余燃料将与冷却渣球的空气相遇并迅速燃烧， 燃烧放出的大量热量不仅增加了出 回转窑高温渣球冷却的难度， 而且又大大提高了工艺的生产成本， 使工艺的商业化、 规模化 运用变得不可实现。
鉴于上述问题， 我们经过反复研究， 曾提出过一种克服上述问题的解决方案 （参见 CN1026403C, CN1040199C 号中国专利文献）， 即采用一种双层复合球团直接还原磷矿石生产 磷酸的工艺， 具体技术解决方案是： 先将磷矿石与配入物料制成球团， 在回转窑内， 球团中 的 P205被还原成磷蒸气并挥发， 在料层上方， 磷蒸气被引入炉内的空气氧化成 P205气体， 然 后在水化装置中被吸收制得磷酸。 该技术方案的最大特点在于： 配入的物料球团采用双层复 合结构， 其内层是由磷矿石、 硅石 （或石灰、 石灰石等） 和碳质还原剂经磨碎、 混匀后造球 而成， 其外层是在内层球团上再裹上一层含碳量大于 20%的固体燃料， 球团的内、 外层配料 时添加粘结剂， 球团采用干燥固结。 球团内层 Ca0/Si02摩尔比可以小于 0. 6或大于 6. 5， 碳 质还原剂为还原磷矿石理论量的 1〜3倍，球团外层固体燃料配量可以为内层球团质量的 5%〜 25%； 球团内、 外层添加的粘结剂可以是沥青、 腐植酸钠、 腐植酸铵、 水玻璃、 亚硫酸盐纸浆 废液、糖浆、木质素磺酸盐中的一种或多种的组合，其添加量为被添加物料重量的 0. 2%〜15% (干基）。 该球团可以采用干燥固结， 固结温度为 80°C〜600°C， 固结时间为 3min〜120min。
我们提出的上述方法采用在球团上裹一层含固体碳的耐高温包裹料，包裹时添加粘结剂， 以使外层包裹料能良好地附着在内层球团上。 将这种双层复合球团经干燥固结后送入回转窑 中， 在回转窑高温带 （1300°C〜140(TC左右） 可以很好地实现磷矿石的碳热还原。 由于在料 球表面人为包覆了一层含固体还原剂 （碳质物料） 的包裹层， 该包裹层可将其内层球团与回 转窑料层上部的含 02和 P205的气流氧化区进行有效地物理隔离。 当这种复合球团在回转窑固 体料层中随回转窑的旋转运动上升到回转窑固体料层表面， 并与回转窑固体料层上部的含 02 和 P205的气流氧化区接触发生对流传质时， 包裹层中的碳便可与氧化区中的 02发生有限的氧 化反应 （因在工业大型回转窑中料球暴露在回转窑料层表面的时间较短， 反应不完全）， 使 02不能传递到内层球团， 保证了内层球团中的还原剂碳不被回转窑气流中的氧所氧化， 使磷 矿石中 P205的还原过程能进行彻底， 实现了工艺过程中磷矿 P205的高还原率。 另一方面， 回 转窑料层上部气流氧化区中的 P205也不可能与复合球团表层包裹层中的碳反应， 因而阻止了 在复合球团上形成磷酸盐或偏磷酸盐化合物， 消除了原有 KPA工艺料球上富含 P205白壳的生 成， 确保了工艺可获得较高的 P2O5收率。 与此同时， 该方法中以固体燃料取代或部分取代了 气体或液体燃料， 这可进一步降低磷酸的生产成本。
此外， 我们提出的上述方法中在造球时还加入了有机粘结剂， 这可使复合球团在干燥脱 水后 （低于球团中碳氧化温度）， 仍可以达到 200kN/个球以上的抗压强度和 10次 /米以上的 落下强度， 因此， 该复合球团可以抵抗在回转窑内受到的机械摩擦力而不被粉碎， 克服了原 有 KPA工艺存在的球团强度差等缺陷， 也克服了球团中碳在回转窑预热带过早氧化的现象， 使复合球团在窑内不出现粉化， 进而避免了粉料造成的回转窑高温结圈致使工艺失败， 保证 了工艺能在设定的条件下顺利进行。
然而， 在我们后续的研究过程中， 又发现了一系列新的技术问题， 这其中就有部分技术 问题体现在窑法磷酸工艺的水化吸磷及氟回收阶段。 窑法磷酸的水化收酸工艺以前主要是借 鉴热法磷酸收酸的方法， 但窑法磷酸的出窑烟气与热法磷酸黄磷燃烧后的烟气存在很大的不 同： 其一， 出窑烟气中 P205的浓度较低， 相同规模产量的烟气量前者是后者的 3〜4倍； 其二， 窑法磷酸的出窑烟气成分复杂， 含氟、 尘、 302等杂质。 因此， 如果仍旧沿用传统的热法磷酸 的收酸方法则会存在较多问题： 首先， 热法磷酸的烟气量小， 相应设备的烟气流速低， 如果 直接套用到窑法磷酸工艺上， 则设备系统的尺寸会相当庞大， 该设备系统不仅结构复杂， 而 且投资和运行成本均较高； 其次， 窑法磷酸的烟气杂质含量复杂， 喷淋酸的腐蚀性更强， 要 防止酸中固体杂质对设备和管道的堵塞， 其收酸工艺和设备结构都需要做进一步的改进； 更 重要的是， 窑法磷酸出窑烟气还含有对人体有害的含氟物质 （以 SiF^P HF形态存在）， 这需 要加以回收利用， 同时避免对环境的污染。
因此， 为了降低窑法磷酸工艺的生产成本和运行费用， 保证产品磷酸质量， 充分利用资 源， 避免环境污染， 对窑法磷酸工艺的水化吸磷及氟回收工艺还亟待本领域技术人员进行进 一步的改进和完善。
【发明内容】
本发明要解决的技术问题是针对窑法磷酸含 P205、 SiF4、 HF及粉尘的出窑烟气， 提供一 种工艺流程简化、 布局合理、 设备投资成本低、 适应性强、 有价元素回收利用率高、 排空废 气环保达标、 磷氟同时回收效果好的从窑法磷酸工艺的出窑烟气中水化吸 P205及回收氟的方 法。
为解决上述技术问题， 本发明提出的技术方案为一种从窑法磷酸工艺的出窑烟气中水化 吸磷的方法， 包括以下步骤：
( 1 )将含 P205和氟的出窑烟气通入一水化塔内， 此前开启与水化塔相连接的酸液循环喷 淋系统， 酸液循环喷淋系统将浓磷酸溶液不断输送到水化塔内的喷淋装置中， 与喷淋的浓磷 酸溶液与进入塔内的含 P2O5和氟的出窑烟气充分接触， 进行传质传热 （烟气通过与循环喷淋 的浓磷酸溶液换热， 温度降低）， 烟气中的 P205与喷淋的循环磷酸溶液中的水发生化学反应生 成磷酸， 生成的磷酸大部分被吸收进喷淋液中， 其余部分以磷酸雾形态保持在气相中， 与此 同时出窑烟气中的含氟物质（以 SIF P HF形态存在）在水化塔内难以被吸收进喷淋液中， 水 化塔中剩余烟气通过其烟气出口排出；
( 2 )水化塔中喷淋落下的磷酸溶液通过一进液口进入酸液循环喷淋系统中， 先流入酸冷 器， 并将磷酸溶液中的热焓部分转移到酸冷器的循环冷却水中， 通过冷却水将磷酸溶液的热 量不断转移， 从酸冷器出口流出的循环磷酸溶液再通过循环泵回送到所述水化塔的喷淋装置 继续进行循环喷淋；
( 3 )从所述烟气出口排出的烟气再依次通过磷酸雾捕集塔和除雾分离塔， 使烟气中夹带 的磷酸雾被进一步捕集， 所述磷酸雾捕集塔和除雾分离塔捕集磷酸雾后形成的稀磷酸溶液通 过管道布置与所述水化塔中的浓磷酸溶液保持串酸； 所谓的串酸优选是指： 将磷酸雾捕集塔 和除雾分离塔捕集的稀磷酸溶液泵送到水化塔， 与水化塔中的浓磷酸溶液混合， 以保持水化 塔酸液循环喷淋系统中酸浓度的稳定； 与此同时， 从水化塔的酸液循环喷淋系统中抽取部分 浓磷酸溶液经过滤装置的澄清， 澄清后的上清液一部分串酸至磷酸雾捕集塔中以保持其酸浓 度的稳定， 一部分则返回水化塔的酸液储液槽；
( 4 )在以上的操作过程中， 酸液循环喷淋系统中的浓磷酸溶液会不断增加， 多出的部分 经过滤后作为粗磷酸产品， 粗磷酸产品进入后续的磷酸精制工序； 另一方面， 配套的在线补 水装置对整个工艺过程实施在线补水， 除雾分离塔的出口烟气则进入后续的氟回收工序。
上述的方法中， 优选的， 所述水化塔中的喷淋装置包括至少两个位于水化塔容腔不同高 度处的喷淋层， 且至少两个的喷淋层中包含一稀磷酸喷淋层和浓磷酸喷淋层， 浓磷酸喷淋层 设于稀磷酸喷淋层上方； 所述循环磷酸喷淋层的进液管与所述酸液循环喷淋系统相连通， 所 述稀磷酸喷淋层的进液管与磷酸雾捕集塔中稀磷酸溶液的循环输送管道相连通以使得磷酸雾 捕集塔中的稀磷酸溶液串酸至水化塔中， 所述酸液循环喷淋系统另通过管道连接至磷酸雾捕 集塔中以使得水化塔中的循环磷酸溶液串酸至磷酸雾捕集塔中。
上述的方法中， 优选的， 所述酸冷器为一个搅拌槽中布置有多个改性石墨管或不锈钢管 环成的换热板， 管中通入循环冷却水， 通过搅拌， 使进入酸冷器的磷酸溶液在换热板上形成 强制对流换热； 所述步骤（1 )中的出窑烟气通过与循环喷淋的循环磷酸溶液换热以及水化塔 内水冷系统的冷却， 温度降至 75 °C〜130 °C ;
上述的方法中， 优选的， 所述水化塔内循环喷淋的磷酸溶液的质量百分比浓度为 60%〜 90%，水化塔内浓磷酸溶液的进塔温度控制为 50 °C〜80 °C，水化塔内喷淋液气比控制在 lL/m3〜 20L/m3。 上述的方法中， 优选的， 所述磷酸精制工序中设有用于对粗磷酸产品进行精制的磷酸精 制槽， 磷酸精制槽内加入活性炭、 硅藻土、 脱硫剂和脱砷剂， 活性炭和硅藻土的用量均控制 为待精制粗磷酸产品质量的 0. 1%〜2%； 所述脱硫剂为可溶性钡盐， 其用量为理论用量 （根据 化学反应式） 的 1〜2倍； 所述脱砷剂为硫化氢或硫化钠， 其用量为理论用量（根据化学反应 式） 的 1〜1. 2倍； 磷酸精制槽内搅拌反应时间为 0. 5h〜2h。 搅拌反应后的产物泵送至过滤 系统过滤后， 滤液即为成品磷酸。
上述的方法中， 优选的， 所述磷酸雾捕集塔为一流态化逆流式洗涤塔， 包括洗涤管和分 离罐， 由水化塔烟气出口排出的烟气进入磷酸雾捕集塔的洗涤管中， 在洗涤管中由下向上喷 射的循环稀磷酸溶液与由上向下的烟气逆流碰撞接触后建立起泡沫区， 烟气穿过泡沫区后与 大面积不断更新的稀磷酸溶液液体表面接触， 在泡沫区发生磷酸雾粒子的捕集、 聚合长大和 热量的传递， 烟气通过绝热蒸发循环稀磷酸溶液中水分的方式被进一步降温到 60°C〜9(TC ; 所述洗涤管中的气体和液体进入下部的分离罐中进行气-液分离， 分离罐同时兼作循环酸槽 (稀磷酸溶液的循环槽），循环稀磷酸溶液落入分离罐底部后绝大部分通过循环泵回送至洗涤 管， 小部分串酸至水化塔中； 所述磷酸雾捕集塔中循环喷淋的稀磷酸溶液的质量百分比浓度 为 10%〜50%； 稀磷酸溶液的温度控制在 40°C〜70°C， 磷酸雾捕集塔内喷淋液气比控制在 3L/m3〜25L/m3。 出水化塔烟气中夹带的磷酸雾绝大部分转入循环的稀磷酸溶液中。
上述的方法中， 优选的， 从所述磷酸雾捕集塔中烟气出口排出的烟气再进入到除雾分离 塔中进行进一步的气-液分离， 除雾分离塔下部设计成类似旋风除尘器的磷酸液滴收捕结构， 利用离心力将已长大的磷酸液滴从烟气中捕集下来， 在除雾分离塔上部安装有丝网除雾器， 将烟气中尚未长大的磷酸雾滴进一步捕集下来； 所述在线补水装置装设在除雾分离塔中且位 于丝网除雾器上方的烟气出口位置， 其一方面作为整个工艺系统的补水设备， 另一方面通过 清洗使烟气中的磷酸雾被进一步捕集， 并兼作丝网除雾器的冲洗装置。
作为一个总的技术构思， 本发明还提供一种从窑法磷酸工艺的出窑烟气中水化吸磷和回 收氟的方法， 该方法是在上述各技术方案的基础上， 进一步采用包括以下步骤的氟回收工序： ( 1 )一级氟吸收： 先将除雾分离塔中排出的含氟烟气输送至一级氟吸收塔的氟硅酸洗涤 管， 烟气自上而下与喷嘴自下而上喷入的循环氟硅酸溶液发生充分的气液两相接触， 并进行 传质传热和化学反应， 反应生成氟硅酸， 同时烟气中的热焓通过绝热蒸发循环氟硅酸溶液中 的水分被部分转移到水蒸气中；
( 2 )一级气液分离： 所述氟硅酸洗涤管中的气体和液体全部转移至氟硅酸分离罐中进行 气液分离， 分离后的气体通过一级氟吸收塔的烟气出口进入二级氟吸收塔的二级氟硅酸洗涤 管中， 分离后的液体留存于氟硅酸分离罐中并通过带循环泵的循环输送管道回送至氟硅酸洗 涤管中进行上述步骤 （1 ) 的操作；
( 3 )二级氟吸收： 进入二级氟硅酸洗涤管中的烟气自上而下与喷嘴自下而上喷入的循环 氟硅酸溶液发生充分的气液两相接触， 并进行传质传热和化学反应， 反应生成氟硅酸， 同时 烟气中的热焓通过热量传递部分转移到循环氟硅酸溶液中；
( 4 )二级气液分离： 所述二级氟硅酸洗涤管中的气体和液体全部转移至二级氟硅酸分离 罐中进行气液分离，分离后的气体通过二级氟吸收塔的烟气出口进入后续的尾吸塔进行处理， 分离后的液体留存于二级氟硅酸分离罐中， 部分通过循环泵回送至二级氟硅酸洗涤管中进行 上述步骤 （3 ) 的操作， 部分输送到一级氟吸收塔的氟硅酸分离罐中；
( 5 )所述一级氟吸收塔中的氟硅酸溶液会不断增加， 多出的氟硅酸溶液经过滤去硅胶后 后作为副产的氟硅酸产品；
所述一级氟吸收塔和二级氟吸收塔均为流态化逆流式洗涤塔， 一级氟吸收塔主要由氟硅 酸洗涤管和氟硅酸分离罐组成， 氟硅酸洗涤管的出口连通至氟硅酸分离罐的中部， 氟硅酸分 离罐的顶部设有烟气出口， 底部设有氟硅酸液出口， 该氟硅酸液出口通过一带循环泵的循环 输送管道与所述氟硅酸洗涤管内的喷嘴相连通；
所述二级氟吸收塔主要由二级氟硅酸洗涤管和二级氟硅酸分离罐组成， 一级氟吸收塔的 烟气出口通过管道连接至二级氟硅酸洗涤管， 二级氟硅酸洗涤管的出口连通至二级氟硅酸分 离罐的中部， 二级氟硅酸分离罐的顶部设有除沫层 （除沫层定期用循环氟硅酸溶液喷淋冲洗 以保持除沫效果） 和烟气出口， 底部设有氟硅酸液出口， 该氟硅酸液出口通过一带循环泵的 循环输送管道与二级氟硅酸洗涤管内的喷嘴及一级氟吸收塔的氟硅酸分离罐相连通。
上述的方法中， 优选的， 所述二级氟吸收塔中的循环输送管道上还设有氟硅酸冷却器， 进入二级氟硅酸洗涤管的循环氟硅酸溶液经过了所述氟硅酸冷却器的冷却处理。
上述的方法中， 优选的， 一级氟吸收采用的循环氟硅酸溶液的质量浓度为 8%〜25% (更 优选 10%〜20%)， 循环氟硅酸溶液的温度为 25 °C〜65 °C (更优选 50 °C〜65 °C )， 喷淋液气比 控制在 3L/m3〜25L/m3 (更优选 3L/m3〜6L/m3 ) ; 二级氟吸收采用的循环氟硅酸溶液的质量浓度 为 0. 5%〜5%， 循环氟硅酸溶液的温度为 25 °C〜60 °C (更优选 45 °C〜60 °C )， 喷淋液气比控制 在 3L/m3〜25L/m3 (更优选 3L/m3〜6L/m3)。
上述的方法中， 优选的， 所述二级氟吸收塔的烟气出口还连接至一尾吸塔， 该尾吸塔为 一喷淋空塔， 尾吸塔的顶部设有烟气出口， 塔内上方设有喷淋层， 底部设有碱吸收液箱， 该 碱吸收液箱的出口通过带循环泵的循环输送管道与尾吸塔内的喷淋层相连通， 控制碱吸收液 的 11值 8。
与现有技术相比， 本发明的优点在于： ( 1 )本发明的水化吸收磷的方法对现有的制磷酸设备及工艺做了大量改进和优化， 使得 整个设备的结构更加简化、 工艺流程更加合理， 具有更强的适应性；
( 2 )本发明的回收氟的方法对现有的回收氟的设备及工艺做了大量改进和优化， 使得整 个氟回收设备的结构更加简化、 工艺流程更加合理， 能更好地配合水化吸收磷酸的工艺路线 需要；
( 3 )在实现相同功能和达到相同效果的前提下， 本发明的水化吸磷及回收氟的设备大幅 简化了系统结构， 降低了设备的投资、 运行和维护费用；
( 4) 本发明优选的技术方案中可以实现窑法磷酸工艺出窑烟气中 P205和氟的同时回收， 实现水化吸收磷和回收氟前后工序的有效配合， 进而得到价值较高的主产品磷酸和副产品氟 硅酸， 使得原料资源得到了更充分的利用， 提高了窑法磷酸工艺的经济效益；
( 5 )本发明优选的技术方案几乎实现了工艺过程废气、 废料、 废液的零排放， 使得整个 工艺的环保性大大提高；
( 6 )本发明的设备完全可适用于低品位磷矿直接生产磷酸， 能够完全适应含 P205和氟的 烟气特点 （特别是窑法磷酸窑气） 及治理需要， 对于我国大量低品位磷矿的有效利用具有十 分重要的意义。
【附图说明】
图 1为本发明具体实施方式中氟回收设备的结构示意图。
图 2为本发明具体实施方式中氟回收工艺的流程图。
图 3为本发明具体实施方式中工艺系统的结构示意图。
图 4为本发明具体实施方式中制磷酸设备的水化塔结构示意放大图。
图 5为本发明具体实施方式中制磷酸设备的磷酸雾捕集塔结构示意放大图。
图 6为本发明具体实施方式中水化吸磷工艺的流程图。
图例说明：
1、 水化塔； 11、 烟气进口； 12、 烟气出口； 13、 喷淋装置； 14、 进液口； 15、 出液口； 16、 酸液储液槽； 17、 水冷系统； 18、 酸冷器； 2、 循环泵； 21、 压滤装置； 22、 填料过滤装 置； 23、 磷酸精制设备； 24、 浓磷酸喷淋层； 25、 稀磷酸喷淋层； 3、 磷酸雾捕集塔； 31、 洗 涤管； 32、 分离罐； 33、 酸液出口； 34、 酸液进口； 35、 喷嘴； 4、 除雾分离塔； 41、 在线水 冲洗装置； 42、 丝网除雾器； 43、 磷酸液滴收捕结构； 5、 一级氟吸收塔； 51、 氟硅酸洗涤管； 52、 氟硅酸分离罐； 53、 氟硅酸液出口； 54、 氟硅酸精制设备； 6、 二级氟吸收塔； 61、 二级 氟硅酸洗涤管； 62、 二级氟硅酸分离罐； 63、 氟硅酸冷却器； 7、 尾吸塔； 8、 风机。
【具体实施方式】 以下结合说明书附图和具体优选的实施例对本发明作进一步描述， 但并不因此而限制本 发明的保护范围。
实施例：
一种本发明的从窑法磷酸工艺的出窑烟气中水化吸磷及回收氟的方法， 本实施例方法需 要用到图 3所示的以下工艺系统， 该工艺系统包括制磷酸系统和回收氟的设备。
本实施例中用到的制磷酸系统包括水化塔 1、 酸液循环喷淋系统、 磷酸雾捕集塔 3和除 雾分离塔 4。
水化塔 1的本体为一喷淋空塔， 水化塔 1的下部设有出窑烟气的烟气进口 11， 顶部设有 经水化吸收后的烟气出口 12， 烟气进口 11上方的水化塔 1容腔中设有喷淋装置 13， 酸液循 环喷淋系统的进液口 14设于水化塔 1的底部， 酸液循环喷淋系统的出液口 15连接至喷淋装 置 13的进液管， 酸液循环喷淋系统中还设有酸液储液槽 16和循环泵 2。 本实施例水化塔 1 的容腔外壁包覆设有水冷系统 17， 且水冷系统 17中的冷却水采用下进上出的方式。 另外， 在酸液循环喷淋系统中靠近其进液口 14的位置设有酸冷器 18; 酸冷器 18的出口与酸液储液 槽 16的进口相连， 酸液储液槽 16的出口通过循环泵 2与喷淋装置 13的进液管相连， 进而形 成一个酸液循环喷淋系统。
磷酸雾捕集塔 3为一个流态化逆流式洗涤塔， 其主要由洗涤管 31和分离罐 32组成， 水 化塔 1的烟气出口 12通过管道与洗涤管 31的进口相连通， 洗涤管 31的出口连通至分离罐 32的中部， 分离罐 32的顶部设有烟气出口 12， 底部设有酸液出口 33， 该酸液出口 33通过 一带循环泵 2的循环输送管道与洗涤管 31内的喷嘴 35相连通 （参见图 5)， 分离罐 32同时 作为磷酸雾捕集塔 3中循环输送管道的酸循环槽。
为了实现水化塔 1与磷酸雾捕集塔 3相互串酸，本实施例中水化塔 1的喷淋装置 13设有 三个位于水化塔 1容腔不同高度处的喷淋层，且三个喷淋层中包含一个稀磷酸喷淋层 25和两 个浓磷酸喷淋层 24 (参见图 4)， 两个浓磷酸喷淋层 24设于稀磷酸喷淋层 25上方； 浓磷酸喷 淋层 24的进液管与上述水化塔 1的酸液循环喷淋系统相连通， 稀磷酸喷淋层 25的进液管则 与磷酸雾捕集塔 3的循环输送管道相连通， 这样首先实现了磷酸雾捕集塔 3中的酸液串至水 化塔 1。 另外， 在上述酸液循环喷淋系统中循环泵 2后的输送管道上通过一支管连接至磷酸 雾捕集塔 3的酸液进口 34处。但考虑与后续磷酸的过滤、精制工序相衔接， 该支管上设有一 填料过滤装置 22， 填料过滤装置 22的进酸口通过支管连通至酸液循环喷淋系统， 填料过滤 装置 22的滤液出口则分成三路， 一路连通至磷酸雾捕集塔 3的酸液进口 34， 一路连通至外 部的磷酸精制设备 23， 另一路则连通至酸液储液槽 16; 填料过滤装置 22的底流出口则通过 管道连接至压滤装置 21的进料口， 压滤装置 21的溢流口通过管道与酸液循环喷淋系统中的 酸液储液槽 16连通， 以充分实现磷酸的回收利用， 保证磷酸的高收率。 填料过滤装置 22的 底流定期用泵送至压滤装置 21过滤， 以排除酸液循环喷淋系统中存在的固体物质。
磷酸雾捕集塔 3的烟气出口 12通过管道与除雾分离塔 4的下部相连通，除雾分离塔 4的 顶部设有烟气出口 12以排出水化吸磷后的烟气， 底部设有酸液出口 33， 该酸液出口 33通过 管道与磷酸雾捕集塔 3的酸液进口 34相连通。 除雾分离塔 4中设在线水冲洗装置 41， 在线 水冲洗装置 41加入的水同时可作为整个水化吸收制磷酸工序的补水，并通过管道逐级返补至 上游的磷酸雾捕集塔 3及水化塔 1中。 除雾分离塔 4的上部安装有丝网除雾器 42， 下部设计 成类似旋风除尘器的磷酸液滴收捕结构 43， 在线水冲洗装置 41安装在丝网除雾器 42上方。
本实施例中用到的回收氟的设备如图 1所示， 包括一级氟吸收塔 5和二级氟吸收塔 6。 一级氟吸收塔 5和二级氟吸收塔 6均采用流态化逆流式洗涤塔。 一级氟吸收塔 5主要由氟硅 酸洗涤管 51和氟硅酸分离罐 52组成，氟硅酸洗涤管 51的进口连通至水化吸磷后的烟气的输 送管道， 氟硅酸洗涤管 51的出口连通至氟硅酸分离罐 52的中部， 氟硅酸分离罐 52的顶部设 有烟气出口 12， 底部设有氟硅酸液出口 53， 该氟硅酸液出口 53通过一带循环泵 2的循环输 送管道与氟硅酸洗涤管 51内的喷嘴 35相连通，氟硅酸分离罐 52则兼做循环输送管道的酸循 环槽。
本实施例中二级氟吸收塔 6的结构与一级氟吸收塔 5相似， 二级氟吸收塔 6主要由二级 氟硅酸洗涤管 61和二级氟硅酸分离罐 62组成，一级氟吸收塔 5的烟气出口 12通过管道与二 级氟硅酸洗涤管 61的进口连通，二级氟硅酸洗涤管 61的出口连通至二级氟硅酸分离罐 62的 中部， 二级氟硅酸分离罐 62的顶部设有烟气出口 12， 底部设有氟硅酸液出口 53， 该氟硅酸 液出口 53通过一带循环泵 2的循环输送管道与二级氟硅酸洗涤管 61内的喷嘴 35相连通。
本实施例中， 二级氟吸收塔 6的循环输送管道上还设有氟硅酸冷却器 63， 氟硅酸冷却器 63的进口与循环泵 2相连， 出口则分成两路， 一路与二级氟硅酸洗涤管 61内的喷嘴 35相连 通， 另一路与二级氟硅酸分离罐 62顶部的喷淋层连通， 二级氟硅酸分离罐 62同样兼做循环 输送管道的酸循环槽。 二级氟吸收塔 6的循环泵 2出口还通过支管与一级氟吸收塔 5的氟硅 酸分离罐 52的进液口相连， 借此可将二级氟吸收塔 6多余的氟硅酸溶液串至一级氟吸收塔 5 内。
为实现全部污染物的达标排放， 在本实施例回收氟的设备最后还连接有尾吸塔 7， 该尾 吸塔 7为一喷淋空塔， 二级氟吸收塔 6的烟气出口 12通过管道与尾吸塔 7的烟气进口 11相 连通。尾吸塔 7的顶部设有烟气出口 12，塔内上方设有喷淋层，底部设有氢氧化钠吸收液箱， 该氢氧化钠吸收液箱出口通过带循环泵 2的循环输送管道与尾吸塔 7内各喷淋层相连， 进而 形成一个尾气吸收循环喷淋系统。 上述的氟硅酸液出口 53另外通过带给料泵的管道与外部的氟硅酸精制设备 54 (或氟盐 加工设备） 连接， 在进入氟硅酸精制设备 54之前可通过压滤装置 21先进行压滤处理， 压滤 装置 21的溢流口再通过管道连接至氟硅酸精制设备 54。
在本实施例提供的上述工艺系统的基础上， 本实施例的从窑法磷酸工艺的出窑烟气中水 化吸磷及回收氟的方法具体包括以下步骤 （具体可参见图 2、 图 3和图 6 ):
1、 水化塔中 P205的水化吸收：
将含 P205和氟的烟气 （特例为 KPA 窑法磷酸工艺中 500°C以上的出窑烟气， P205含量 80g/Nm3 ) 由水化塔 1下部的烟气进口 11通入塔内， 此前开启酸液循环喷淋系统的循环泵 2， 使水化塔 1中的浓磷酸溶液通过上、 中两层浓磷酸喷淋层 24喷出， 最上层浓磷酸喷淋层 24 的部分喷嘴从斜下方喷向塔内壁， 其余喷嘴垂直向下喷出， 中、 下两层喷淋层的喷嘴垂直向 下喷淋， 喷淋的浓磷酸溶液与进入塔内的含 P205和氟的烟气逆流充分接触， 进行传质传热， 烟气中的 P205与喷淋的浓磷酸溶液中的水发生化学反应生成磷酸， 生成的磷酸一半以上被吸 收进喷淋液， 其余部分形成磷酸雾保持在气相中， 而烟气中的氟（例如 SiF^P HF等）在浓磷 酸和较高温度条件下， 很难被吸收进喷淋液中； 烟气通过与循环喷淋的较低温浓磷酸溶液换 热以及水化塔 1内水冷系统 17的冷却， 温度降至 75°C〜130°C， 出水化塔 1的循环浓磷酸溶 液温度则被提高到 70°C〜95°C。 根据烟气中水分的含量大小， 循环喷淋的浓磷酸溶液的质量 百分比浓度可选择在 60%〜90%的范围内 （本实施例采用 70%〜85%浓度的磷酸溶液）， 水化塔 内浓磷酸溶液的进塔温度控制为 50°C〜80°C， 喷淋液气比控制在 3L/m3〜20L/m3。在出塔烟气 中夹带有较多以雾状形态存在磷酸雾， 不能在水化塔 1中沉降下来， 随烟气一起被带出水化 塔 1。 该水化塔 1具有冷却烟气和水化吸收 P205的双重功能， 其中主要发生的化学反应如下。
P205 + 3H20 = 2¾P04
水化塔 1中喷淋落下的浓磷酸溶液最后通过进液口 14进入酸液循环喷淋系统，然后流入 酸冷器 18中， 酸冷器 18的结构为一个搅拌槽中布置有若干不锈钢管环成的换热板， 管中通 入循环冷却水， 通过搅拌， 使进入酸冷器 18的磷酸溶液在换热板上形成强制对流换热， 提高 传热效率， 将浓磷酸中的热焓部分转移到酸冷器 18的循环冷却水中， 通过冷却水将循环浓磷 酸溶液的热量不断转移。 从酸冷器 18出口流出的循环酸液进入酸液储液槽 16， 并通过循环 泵 2再次回送到上、 中两层浓磷酸喷淋层 24的各个喷嘴进行循环喷淋。
2、 磷酸雾捕集塔中磷酸雾的捕集：
由水化塔 1顶部烟气出口 12排出的气相物质 （即烟气） 进入磷酸雾捕集塔 3的洗涤管 31 中， 该塔为一台流态化逆流洗涤塔， 在洗涤管 31 中由下向上喷射循环稀磷酸溶液， 稀磷 酸溶液与由上向下的高速烟气流碰撞接触后在气 -液界面区域形成强烈的湍动区域，流体动量 达到平衡后建立起一定高度的稳定的泡沫区（泡沫柱）， 烟气穿过泡沫区， 与大面积不断更新 的磷酸溶液液体表面接触， 在泡沫区发生粒子的捕集、 聚合长大和热量的传递， 烟气中夹带 的磷酸雾绝大部分转入循环稀磷酸溶液， 吸收区内烟气表观流速为 10m/S〜30m/s， 液气比为 3L/m3〜25L/m3。烟气通过绝热蒸发循环稀磷酸溶液中水分的方式被进一步降温到 60 °C〜75 °C。 与传统热法磷酸文丘里除雾器相比， 在同样的除雾效果情况下， 本发明的磷酸雾捕集塔可大 大减少设备的动力压头损失， 降低收酸装置能耗。
磷酸雾捕集塔 3中循环喷淋的酸液采用 10%〜50%质量浓度的稀磷酸溶液， 洗涤管 31中 的气体和液体进入塔下部的分离罐 32中进行气-液分离， 循环酸液落入分离罐 32底部， 该塔 的分离罐 32同时兼作循环酸槽， 底部的稀磷酸溶液再通过循环泵 2回送至洗涤管 31或者根 据需要串酸至水化塔 1的稀磷酸喷淋层 25中。
3、 除雾分离塔中磷酸雾的捕集：
从磷酸雾捕集塔 3中烟气出口 12排出的烟气再进入到除雾分离塔 4中进行进一步的气- 液分离， 以进一步除去烟气中的磷酸雾， 除雾分离塔下部设计成类似旋风除尘器的磷酸液滴 收捕结构 43， 利用离心力将已长大的磷酸液滴从烟气中捕集下来， 在除雾分离塔上部安装有 丝网除雾器 42， 将烟气中尚未长大的磷酸雾滴进一步捕集下来以保证设备对 P205的直收率； 除雾分离塔 4排出的水化吸磷后的烟气则送入氟回收设备中进行回收氟的处理。
由于磷酸的水化吸收过程化合烟气中 P205需要消耗水， 另外烟气降温过程中从喷淋酸液 中蒸发了部分水分， 因此水化吸收过程需要不断补充水， 本实施例工艺系统中需要补充的水 量全部从除雾分离塔 4烟气出口 12处补入， 此时在线水冲洗装置 41不仅充当补水装置， 同 时兼做除雾分离塔 4上部丝网除雾器的冲洗装置。 由于全部的补水都加入到了除雾分离塔 4 中， 而除雾分离塔 4的底液又通过磷酸雾捕集塔 3的酸液进口 34回流至磷酸雾捕集塔 3中， 因此磷酸雾捕集塔 3中循环酸液浓度会逐步降低， 而另一方面， 水化塔 1中由于不断吸收烟 气中的 P205， 其中循环酸液浓度会逐渐增高， 因此， 水化塔 1和磷酸雾捕集塔 3的循环酸液 系统需要进行串酸， 以保持各自循环酸液浓度的稳定， 水化塔 1串至磷酸雾捕集塔 3的酸在 填料过滤装置 22中澄清、 过滤后引至磷酸雾捕集塔 3， 磷酸雾捕集塔 3串至水化塔 1的酸则 直接从磷酸雾捕集塔 3的循环泵 2出口处引出即可。 由于水化塔 1中的循环酸液吸收了烟气 中的粉尘等杂质， 为了不让这些杂质累积， 需要从水化塔 1的酸液循环喷淋系统中引出多余 的酸液 （对应物料平衡的产酸量） 先到填料过滤装置 22进行澄清过滤 （一级过滤）， 澄清液 一部分串酸至磷酸雾捕集塔 3， 另一部分则作为粗成品磷酸进入精制工序， 加入活性碳、 硅 藻土及钡盐， 脱去粗磷酸的颜色和 S04 2—， 然后用板框压滤装置 21 (二级过滤） 除杂、 提纯后 得到浓磷酸成品。 4、 一级氟吸收：
先将水化吸磷后的烟气输送至一级氟吸收塔 5的氟硅酸洗涤管 51，烟气中大部分的氟 (主 要是四氟化硅） 自上而下与喷嘴 35自下而上喷入的循环氟硅酸溶液 （质量浓度为 10%〜20%) 发生充分的气液两相接触， 并进行传质传热和化学反应， 烟气中的大部分氟与水反应后生成 氟硅酸， 同时烟气中的热焓通过热量传递大部分转移到循环氟硅酸溶液中； 烟气通过绝热蒸 发循环氟硅酸溶液中的水分和传热给循环氟硅酸溶液的方式被进一步降温到 50°C〜7(TC ; 此 步骤中主要发生的化学反应如下：
3SiF4 +3¾0 = 2H2SiF6 + Si02 · ¾0。
5、 一级气液分离：
在氟硅酸洗涤管 51中最后得到的产物全部转移至氟硅酸分离罐 52中进行气液分离， 分 离后的气体通过一级氟吸收塔 5的烟气出口进入二级氟吸收塔 6的二级氟硅酸洗涤管 61中， 分离后的液体留存于氟硅酸分离罐 52中并通过带循环泵 2的循环输送管道回送至氟硅酸洗涤 管 51中进行上述步骤 4的操作。
6、 二级氟吸收：
进入二级氟硅酸洗涤管 61中的烟气（剩余的绝大部分的含氟物质， 主要是四氟化硅） 自 上而下与喷嘴 35 自下而上喷入的循环氟硅酸溶液 （质量浓度为 0. 5%〜1. 5%) 发生充分的气 液两相接触， 并进行传质传热和化学反应， 反应生成氟硅酸， 同时烟气中的热焓通过热量传 递再次转移到循环氟硅酸溶液中； 经步骤 3处理后的产物的温度进一步降至 60°C以下； 本步 骤中主要发生的化学反应与步骤 4相同。
7、 二级气液分离：
在二级氟硅酸洗涤管 61中最后得到的产物全部转移至二级氟硅酸分离罐 62中进行气液 分离， 二级氟硅酸分离罐 62顶部设除雾单元， 以除去烟气中夹带的雾沫， 提高 F的吸收率， 除雾单元通过顶部喷入循环氟硅酸溶液进行清洗。 分离后的气体通过二级氟吸收塔 6的烟气 出口进入后续的尾吸塔 7进行处理，分离后的液体留存于二级氟硅酸分离罐 62中通过带循环 泵 2的循环输送管道回送至二级氟硅酸洗涤管 61中进行上述步骤 6的操作，该循环输送管道 安装有氟硅酸冷却器 63， 以便移除循环氟硅酸溶液中的部分热量， 使氟吸收反应能在较适宜 的温度下进行。 进入二级氟硅酸洗涤管 61 的循环氟硅酸溶液经过了氟硅酸冷却器 63 (常规 冷却设备） 的冷却处理； 部分多余的循环氟硅酸溶液则可直接排放到一级氟吸收塔 5的氟硅 酸分离罐 52中。
一级氟吸收塔 5和二级氟吸收塔 6中的循环氟硅酸溶液因吸收烟气中的氟 （主要是四氟 化硅）有累积， 一级氟吸收塔 5中的氟硅酸浓度因吸收烟气中的 SiF^P HF而增浓， 二级氟吸 收塔 6中多余的循环氟硅酸溶液则排放至一级氟吸收塔 5中使其浓度维持恒定， 最终一级氟 吸收塔 5中多余的循环氟硅酸溶液经给料泵送至压滤装置 21进行压滤除去其中的硅胶等固体 物， 滤液去氟硅酸精制工序精制成氟硅酸成品 （浓度为 12%左右） 或加工成氟盐产品； 滤渣 为硅胶， 洗净除杂后作为副产品。
8、 尾吸净化处理：
进入后续尾吸塔 7进行处理的烟气在尾吸塔 7的向上运动过程中与向下喷淋的 NaOH溶液 进行逆流接触， 尾吸塔 7底部吸收液箱通过循环泵 2与塔内各喷淋层相连， 形成一个循环喷 淋系统； 为了保持吸收液的吸收能力， 吸收液的 PH值保持在 8以上， 需要不断加入稀 NaOH 溶液， 而吸收液因稀 NaOH溶液的加入和烟气中 P205、 氟等杂质的吸收会有累积， 需要不断排 出进行污水处理， 处理回收的水可回用到窑法磷酸的原料工序； 烟气中剩余的污染物 （P205、 SiF4、 粉尘等） 被喷淋液吸收， 烟气得到进一步的洗涤净化， 达到国家排放标准 （气体氟含 量降低到 9mg/m3以下）， 然后通过引风机排至烟囱排放。 本步骤中主要发生的化学反应如下。
3SiF4 + 6Na0H = 2N¾SiF6 + N¾Si03 + 3¾0
P205 + 6Na0H = 2N¾P04+ 3H20。
以上仅为本发明的优选实施例， 在上述技术方案的基础上所作的等同修改、变换及润色， 均在本发明的保护范围内。

Claims

权 利 要 求
1、 一种从窑法磷酸工艺的出窑烟气中水化吸磷的方法， 包括以下步骤：
( 1 ) 将含 P205和氟的出窑烟气通入一水化塔内， 此前开启与水化塔相连接的酸液循 环喷淋系统， 酸液循环喷淋系统将浓磷酸溶液不断输送到水化塔内的喷淋装置中， 向下喷 淋的浓磷酸溶液与进入塔内的含 P205和氟的出窑烟气逆流充分接触，进行传质传热，烟气 中的 P205与喷淋的浓磷酸溶液中的水发生化学反应生成磷酸，生成的磷酸大部分被吸收进 喷淋液中， 其余部分形成磷酸雾保持在气相中， 与此同时出窑烟气中的含氟物质在水化塔 内很难被吸收进喷淋液中， 水化塔中剩余烟气通过其烟气出口排出；
( 2 ) 水化塔中喷淋落下的磷酸溶液最后通过一进液口进入酸液循环喷淋系统中， 先 流入酸冷器， 并将磷酸溶液中的热焓部分转移到酸冷器的循环冷却水中， 通过冷却水将磷 酸溶液的热量不断转移， 从酸冷器出口流出的循环磷酸溶液再通过循环泵回送到所述水化 塔的喷淋装置继续进行循环喷淋；
( 3 ) 从所述烟气出口排出的烟气再依次通过磷酸雾捕集塔和除雾分离塔， 使出水化 塔烟气中夹带的磷酸雾被进一步捕集， 所述磷酸雾捕集塔和除雾分离塔捕集磷酸雾后形成 的稀磷酸溶液通过管道布置与所述水化塔中的浓磷酸溶液保持串酸；
( 4 ) 在以上的操作过程中， 酸液循环喷淋系统中的浓磷酸溶液会不断增加， 多出的 部分经过滤后作为粗磷酸产品， 粗磷酸产品进入后续的磷酸精制工序； 另一方面， 配套的 在线补水装置对整个工艺过程实施在线补水， 除雾分离塔排出的含氟烟气则进入后续的氟 回收工序。
2、 根据权利要求 1 所述的方法， 其特征在于： 所述水化塔中的喷淋装置包括至少两 个位于水化塔容腔不同高度处的喷淋层， 且至少两个的喷淋层中包含一稀磷酸喷淋层和浓 磷酸喷淋层， 浓磷酸喷淋层设于稀磷酸喷淋层上方； 所述浓磷酸喷淋层的进液管与所述酸 液循环喷淋系统相连通， 所述稀磷酸喷淋层的进液管与磷酸雾捕集塔中稀磷酸溶液的循环 输送管道相连通以使得磷酸雾捕集塔中的稀磷酸溶液串酸至水化塔中， 所述酸液循环喷淋 系统另通过管道连接至磷酸雾捕集塔中以使得水化塔中的浓磷酸溶液串酸至磷酸雾捕集 塔中。
3、 根据权利要求 1 所述的方法， 其特征在于： 所述酸冷器为一个搅拌槽中布置有多 个改性石墨管或不锈钢管环成的换热板， 管中通入循环冷却水， 通过搅拌， 使进入酸冷器 的磷酸溶液在换热板上形成强制对流换热； 所述步骤 （1 ) 中的出窑烟气通过与循环喷淋 的浓磷酸溶液换热以及水化塔内水冷系统的冷却， 温度降至 75 °C〜130°C。
4、 根据权利要求 1 所述的方法， 其特征在于： 所述水化塔内循环喷淋的浓磷酸溶液 的质量百分比浓度为 60%〜90%， 水化塔内浓磷酸溶液的进塔温度控制为 50°C〜80°C， 水 化塔内喷淋液气比控制在 lL/m3〜20L/m3。
5、 根据权利要求 1 所述的方法， 其特征在于： 所述磷酸精制工序中设有用于对粗磷 酸产品进行精制的磷酸精制槽， 磷酸精制槽内加入有活性炭、 硅藻土、 脱硫剂和脱砷剂， 活性炭和硅藻土的用量均控制为待精制粗磷酸产品质量的 0.1%〜2%； 所述脱硫剂为可溶 性钡盐， 其用量为理论用量的 1〜2倍； 所述脱砷剂为硫化氢或硫化钠， 其用量为理论用 量的 1〜1.2倍； 磷酸精制槽内搅拌反应时间为 0.51！〜 2h。
6、 根据权利要求 1〜5中任一项所述的方法， 其特征在于： 所述磷酸雾捕集塔为一流 态化逆流式洗涤塔， 包括洗涤管和分离罐， 由水化塔烟气出口排出的烟气进入磷酸雾捕集 塔的洗涤管中， 在洗涤管中由下向上喷射的循环稀磷酸溶液与由上向下的烟气逆流碰撞接 触后建立起泡沫区， 烟气穿过泡沫区后与大面积不断更新的稀磷酸溶液液体表面接触， 在 泡沫区发生粒子的捕集、 聚合长大和热量的传递， 烟气通过绝热蒸发循环稀磷酸溶液中水 分的方式被进一步降温到 60°C〜90°C ;所述洗涤管中的气体和液体进入下部的分离罐中进 行气-液分离，循环稀磷酸溶液落入分离罐底部后再通过循环泵回送至洗涤管且部分串酸至 水化塔中； 所述磷酸雾捕集塔中循环喷淋的稀磷酸溶液的质量浓度为 10%〜50%； 稀磷酸 溶液的温度控制在 40°C〜70°C， 磷酸雾捕集塔内喷淋液气比控制在 3L/m3〜25L/m3。
7、 根据权利要求 6所述的方法， 其特征在于： 从所述磷酸雾捕集塔中烟气出口排出 的烟气再进入到除雾分离塔中进行进一步的气-液分离，除雾分离塔下部设计成类似旋风除 尘器的磷酸液滴收捕结构， 利用离心力将已长大的磷酸液滴从烟气中捕集下来， 在除雾分 离塔上部安装有丝网除雾器， 将烟气中尚未长大的磷酸雾滴进一步捕集下来； 所述在线补 水装置装设在除雾分离塔中且位于丝网除雾器的上方， 并兼作丝网除雾器的冲洗装置。
8、 一种从窑法磷酸工艺的出窑烟气中水化吸磷和回收氟的方法， 其特征在于， 在权 利要求 1〜7中任一项所述方法的基础上， 进一步采用包括以下步骤的氟回收工序：
( 1 ) 一级氟吸收： 先将除雾分离塔中排出的含氟烟气输送至一级氟吸收塔的氟硅酸 洗涤管， 烟气自上而下与喷嘴自下而上喷入的循环氟硅酸溶液发生充分的气液两相接触， 并进行传质传热和化学反应， 反应生成氟硅酸， 同时烟气中的热焓通过绝热蒸发循环氟硅 酸溶液中的水分被部分转移到水蒸气中；
( 2 ) 一级气液分离： 所述氟硅酸洗涤管中的气体和液体全部转移至氟硅酸分离罐中 进行气液分离， 分离后的气体通过一级氟吸收塔的烟气出口进入二级氟吸收塔的二级氟硅 酸洗涤管中， 分离后的液体留存于氟硅酸分离罐中并通过带循环泵的循环输送管道回送至 氟硅酸洗涤管中进行上述步骤 （1 ) 的操作；
( 3 ) 二级氟吸收： 进入二级氟硅酸洗涤管中的烟气自上而下与喷嘴自下而上喷入的 循环氟硅酸溶液发生充分的气液两相接触，并进行传质传热和化学反应，反应生成氟硅酸， 同时烟气中的热焓通过热量传递部分转移到循环氟硅酸溶液中；
( 4 ) 二级气液分离： 所述二级氟硅酸洗涤管中的气体和液体全部转移至二级氟硅酸 分离罐中进行气液分离， 分离后的气体通过二级氟吸收塔的烟气出口进入后续的尾吸塔进 行处理， 分离后的液体留存于二级氟硅酸分离罐中， 部分通过循环泵回送至二级氟硅酸洗 涤管中进行上述步骤 （3 ) 的操作， 部分输送到一级氟吸收塔的氟硅酸分离罐中；
( 5 ) 所述一级氟吸收塔中的氟硅酸溶液会不断增加， 多出的氟硅酸溶液经过滤去硅 胶后后作为副产的氟硅酸产品；
所述一级氟吸收塔和二级氟吸收塔均为流态化逆流式洗涤塔， 一级氟吸收塔主要由氟 硅酸洗涤管和氟硅酸分离罐组成， 氟硅酸洗涤管的出口连通至氟硅酸分离罐的中部， 氟硅 酸分离罐的顶部设有烟气出口， 底部设有氟硅酸液出口， 该氟硅酸液出口通过一带循环泵 的循环输送管道与所述氟硅酸洗涤管内的喷嘴相连通；
所述二级氟吸收塔主要由二级氟硅酸洗涤管和二级氟硅酸分离罐组成， 一级氟吸收塔 的烟气出口通过管道连接至二级氟硅酸洗涤管， 二级氟硅酸洗涤管的出口连通至二级氟硅 酸分离罐的中部， 二级氟硅酸分离罐的顶部设有除沫层和烟气出口， 底部设有氟硅酸液出 口， 该氟硅酸液出口通过一带循环泵的循环输送管道与二级氟硅酸洗涤管内的喷嘴及一级 氟吸收塔的氟硅酸分离罐相连通。
9、 根据权利要求 8 所述的方法， 其特征在于， 所述二级氟吸收塔中的循环输送管道 上还设有氟硅酸冷却器， 进入二级氟硅酸洗涤管的循环氟硅酸溶液经过了所述氟硅酸冷却 器的冷却处理。
10、 根据权利要求 8或 9所述的方法， 其特征在于， 一级氟吸收采用的循环氟硅酸溶 液的质量浓度为 8%〜25%， 循环氟硅酸溶液的温度为 25 °C〜65 °C， 喷淋液气比控制在 3L/m3〜25L/m3; 二级氟吸收采用的循环氟硅酸溶液的质量浓度为 0.5%〜5%， 循环氟硅酸 溶液的温度为 25 °C〜60°C， 喷淋液气比控制在 3L/m3〜25L/m3。
PCT/CN2013/081225 2013-06-04 2013-08-09 从窑法磷酸工艺的出窑烟气中水化吸磷及回收氟的方法 Ceased WO2014194570A1 (zh)

Priority Applications (2)

Application Number Priority Date Filing Date Title
RU2015144714A RU2663032C2 (ru) 2013-06-04 2013-08-09 Абсорбция фосфора путем гидратации и восстановления фтора в процессе обжига в печи для получения фосфорной кислоты
US14/958,914 US10023463B2 (en) 2013-06-04 2015-12-03 Phosphorus absorption by hydration and fluorine recovery for fume exiting kiln in kiln phosphoric acid process

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201310218625.0A CN104211035B (zh) 2013-06-04 2013-06-04 从窑法磷酸工艺的出窑烟气中水化吸磷及回收氟的方法
CN201310218625.0 2013-06-04

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US14/958,914 Continuation-In-Part US10023463B2 (en) 2013-06-04 2015-12-03 Phosphorus absorption by hydration and fluorine recovery for fume exiting kiln in kiln phosphoric acid process

Publications (1)

Publication Number Publication Date
WO2014194570A1 true WO2014194570A1 (zh) 2014-12-11

Family

ID=52007456

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2013/081225 Ceased WO2014194570A1 (zh) 2013-06-04 2013-08-09 从窑法磷酸工艺的出窑烟气中水化吸磷及回收氟的方法

Country Status (4)

Country Link
US (1) US10023463B2 (zh)
CN (1) CN104211035B (zh)
RU (1) RU2663032C2 (zh)
WO (1) WO2014194570A1 (zh)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107445186A (zh) * 2017-09-01 2017-12-08 河北正润环境科技有限公司 钢铁精加工酸洗废液回收利用装置及方法
CN108310794A (zh) * 2018-03-14 2018-07-24 红河绿地环保科技发展有限公司 一种消除烟气排放口白雾水汽的方法
CN108744896A (zh) * 2018-07-20 2018-11-06 四川思达能环保科技有限公司 一种氮氧化物烟气吸收制酸系统
CN111644009A (zh) * 2020-06-16 2020-09-11 浙江优创材料科技股份有限公司 一种对硝基苯甲酸生产中夹带物料处理系统及其使用方法
CN113860276A (zh) * 2021-11-09 2021-12-31 杭州亚太化工设备有限公司 一种炉法磷酸生产系统以及生产工艺
CN114887425A (zh) * 2022-06-02 2022-08-12 淮阴工学院 一种化灰尾气的抗堵塞洗涤塔
CN115738496A (zh) * 2022-11-29 2023-03-07 安徽龙华化工股份有限公司 一种五氧化二磷生产用尾气处理回收磷酸系统
CN116462200A (zh) * 2023-04-24 2023-07-21 中国五环工程有限公司 基于真空膜蒸馏法的氟硅酸浓缩方法
CN118877839A (zh) * 2024-08-09 2024-11-01 江苏捷创新材料有限责任公司 一种电子级硫酸连续性生产设备
CN119015851A (zh) * 2024-10-28 2024-11-26 中石化西南石油工程有限公司 一种防酸雾扩散中和系统及使用方法和混酸车

Families Citing this family (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104211033B (zh) * 2013-06-04 2016-06-15 四川玖长科技有限公司 用于从窑法磷酸工艺的出窑烟气中制磷酸的设备
CN104828794B (zh) * 2015-05-08 2016-08-31 浙江嘉化集团股份有限公司 从三甲脂废液焚烧炉排放烟气中回收五氧化二磷的方法
CN106540519B (zh) * 2016-11-03 2022-10-11 中国神华能源股份有限公司 烟气处理装置和应用其的烟气处理方法
CN108341405A (zh) * 2018-01-16 2018-07-31 湖北兴福电子材料有限公司 一种黄磷储槽含磷烟气回收再利用的装置及方法
CN108355479B (zh) * 2018-04-19 2023-12-12 福建璞睿泰科新材料科技有限公司 一种含氟气体净化回收系统及含氟气体除氟方法
CN110193256A (zh) * 2019-07-03 2019-09-03 郑州机械研究所有限公司 一种铜磷钎料生产用两级烟尘回收装置及方法
CN110360577A (zh) * 2019-08-16 2019-10-22 江苏鼎新环保科技有限公司 一种含氯废液焚烧处理系统
CN110368792A (zh) * 2019-08-19 2019-10-25 北京首钢国际工程技术有限公司 一种配带串并联烟道的双塔双循环湿法脱硫装置
CN110436426B (zh) * 2019-09-12 2024-08-20 中化重庆涪陵化工有限公司 含磷含氟废水处理联产磷酸的系统及方法
CN112694068A (zh) * 2021-02-01 2021-04-23 金川集团股份有限公司 一种冶炼烟气生产试剂硫酸的装置及方法
CN113058404A (zh) * 2021-04-27 2021-07-02 天津辰创环境工程科技有限责任公司 高含磷、含氯、含硫废气/废液处理系统及方法
CN116281904A (zh) * 2023-01-17 2023-06-23 昆明川金诺化工股份有限公司 一种降低半水湿法磷酸生产中副产氟硅酸磷含量的方法
CN116571352A (zh) * 2023-05-22 2023-08-11 浙江双屿实业有限公司 一种阳极泥烟气净化与硒回收系统及其使用方法
CN118512897B (zh) * 2024-07-19 2024-09-10 烟台冰轮环保科技有限公司 一种具有自清洁结构的二氧化碳精馏塔

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1071097A (zh) * 1991-09-28 1993-04-21 云南昆明磷肥厂 处理含氟废气的方法
CN1150550A (zh) * 1996-03-13 1997-05-28 刘传书 贫泥磷热风焚烧炉制硅钙磷钾肥及磷酸
CN101049920A (zh) * 2007-05-14 2007-10-10 湖北三新磷酸有限公司 窑法磷酸的磷氟吸收分离方法
CN202015577U (zh) * 2011-03-16 2011-10-26 建业庆松集团有限公司 高效逆喷洗涤器
CN102826552A (zh) * 2012-09-18 2012-12-19 贵州开磷（集团）有限责任公司 一种从磷酸萃取尾气中回收利用氟硅酸的方法
CN202715347U (zh) * 2012-06-08 2013-02-06 云南澄江盘虎化工有限公司 一种发电用黄磷尾气净化塔

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3273713A (en) 1966-09-20 Removal of fluorine compounds from phosphoric acid
US2247373A (en) 1939-01-24 1941-07-01 Charles E Hartford Making phosphoric acid
US3024086A (en) * 1959-06-15 1962-03-06 Phillips Petroleum Co Disposal of fluorine wastes
NL267418A (zh) 1960-08-01
US4389384A (en) 1982-05-10 1983-06-21 Occidental Research Corporation Process for reducing phosphate ore
US7910080B2 (en) 2004-06-04 2011-03-22 Jdcphosphate, Inc. Phosphorous pentoxide producing methods
RU2420452C1 (ru) * 2009-11-19 2011-06-10 Общество с ограниченной ответственностью "ЛЕННИИГИПРОХИМ" (ООО "ЛНГХ") Способ получения термической фосфорной кислоты и устройство для его реализации

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1071097A (zh) * 1991-09-28 1993-04-21 云南昆明磷肥厂 处理含氟废气的方法
CN1150550A (zh) * 1996-03-13 1997-05-28 刘传书 贫泥磷热风焚烧炉制硅钙磷钾肥及磷酸
CN101049920A (zh) * 2007-05-14 2007-10-10 湖北三新磷酸有限公司 窑法磷酸的磷氟吸收分离方法
CN202015577U (zh) * 2011-03-16 2011-10-26 建业庆松集团有限公司 高效逆喷洗涤器
CN202715347U (zh) * 2012-06-08 2013-02-06 云南澄江盘虎化工有限公司 一种发电用黄磷尾气净化塔
CN102826552A (zh) * 2012-09-18 2012-12-19 贵州开磷（集团）有限责任公司 一种从磷酸萃取尾气中回收利用氟硅酸的方法

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107445186B (zh) * 2017-09-01 2023-06-27 河北正润环境科技有限公司 钢铁精加工酸洗废液回收利用装置及方法
CN107445186A (zh) * 2017-09-01 2017-12-08 河北正润环境科技有限公司 钢铁精加工酸洗废液回收利用装置及方法
CN108310794A (zh) * 2018-03-14 2018-07-24 红河绿地环保科技发展有限公司 一种消除烟气排放口白雾水汽的方法
CN108744896A (zh) * 2018-07-20 2018-11-06 四川思达能环保科技有限公司 一种氮氧化物烟气吸收制酸系统
CN108744896B (zh) * 2018-07-20 2023-12-15 四川思达能环保科技有限公司 一种氮氧化物烟气吸收制酸系统
CN111644009A (zh) * 2020-06-16 2020-09-11 浙江优创材料科技股份有限公司 一种对硝基苯甲酸生产中夹带物料处理系统及其使用方法
CN113860276A (zh) * 2021-11-09 2021-12-31 杭州亚太化工设备有限公司 一种炉法磷酸生产系统以及生产工艺
CN113860276B (zh) * 2021-11-09 2024-10-29 杭州亚太化工设备有限公司 一种炉法磷酸生产系统以及生产工艺
CN114887425A (zh) * 2022-06-02 2022-08-12 淮阴工学院 一种化灰尾气的抗堵塞洗涤塔
CN115738496A (zh) * 2022-11-29 2023-03-07 安徽龙华化工股份有限公司 一种五氧化二磷生产用尾气处理回收磷酸系统
CN116462200A (zh) * 2023-04-24 2023-07-21 中国五环工程有限公司 基于真空膜蒸馏法的氟硅酸浓缩方法
CN118877839A (zh) * 2024-08-09 2024-11-01 江苏捷创新材料有限责任公司 一种电子级硫酸连续性生产设备
CN119015851A (zh) * 2024-10-28 2024-11-26 中石化西南石油工程有限公司 一种防酸雾扩散中和系统及使用方法和混酸车

Also Published As

Publication number Publication date
CN104211035A (zh) 2014-12-17
US20160152475A1 (en) 2016-06-02
CN104211035B (zh) 2016-08-31
RU2015144714A (ru) 2017-07-17
RU2663032C2 (ru) 2018-08-01
US10023463B2 (en) 2018-07-17

Similar Documents

Publication Publication Date Title
WO2014194570A1 (zh) 从窑法磷酸工艺的出窑烟气中水化吸磷及回收氟的方法
WO2014194564A1 (zh) 用于从窑法磷酸工艺水化吸磷后的烟气中回收氟的设备及工艺
WO2014194569A1 (zh) 用于从窑法磷酸工艺的出窑烟气中制磷酸的设备
CN104211030B (zh) 改进型的用回转窑规模化生产磷酸的方法
WO2016086826A1 (zh) 用于从窑法磷酸工艺的出窑烟气中制磷酸的改进型设备及制磷酸的工艺
CN101343050B (zh) 一种用立式密闭隔烟窑炉生产黄磷或磷酸的方法及设备
WO2008052465A1 (fr) Procédé de désulfuration et de dépoussiérage par voie humide de gaz de carneau calciné
CN104445118B (zh) 用于从窑法磷酸工艺的出窑烟气中制磷酸的工艺
CN101214936B (zh) 磷矿石熔融生产黄磷的方法
CA2745480A1 (en) System for producing silicon with improved resource utilization
CN109319996A (zh) 一种高盐高cod废水的处理方法
CN103836948B (zh) 一种高碳钼镍矿用的沸腾焙烧炉及系统
CN105217589B (zh) 黄磷联产钾盐、碳酸钠和氧化铝的节能方法
CN104211032A (zh) 窑法磷酸工艺中还原磷矿石的回转窑及解决窑法磷酸工艺窑尾结圈的方法
CN104229755A (zh) 硫磺制备硫酸的方法
CN101804974A (zh) 黄磷直接制取食品级高纯度磷酸的方法
CN204356085U (zh) 用于从窑法磷酸工艺的出窑烟气中制磷酸的改进型设备
CN206069375U (zh) 一种湿块矿配加焦粒型磷酸制备系统
CN105197901B (zh) 含钾磷矿制备黄磷、钾盐、碳酸钠和氧化铝的节能方法
CN220165835U (zh) 液磷处理系统以及黄磷炉气处理系统
CN105623740A (zh) 清洁煤气制备方法及制备系统
CN105236370A (zh) 一种连续化生产h型五氧化二磷的方法
CN113912021A (zh) 工业副产品石膏协同冶金渣熔液生产硫磺联产水泥熟料的系统及工艺
CN102951660A (zh) 一种处理环己酮皂化废碱的方法
JPS6163504A (ja) 石膏の処理方法

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 13886260

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

ENP Entry into the national phase

Ref document number: 2015144714

Country of ref document: RU

Kind code of ref document: A

122 Ep: pct application non-entry in european phase

Ref document number: 13886260

Country of ref document: EP

Kind code of ref document: A1