CN114574262A - Coal-fired catalyst produced by using titanium white waste acid and preparation method thereof - Google Patents

Abstract

The invention discloses a coal-fired catalyst produced by utilizing titanium dioxide waste acid and a preparation method thereof, belonging to the technical field of preparation of inorganic chemical materials. Mixing one or more of low-grade copper oxide, sulfuric acid waste residues and cuprous sulfide with a titanium white waste acid solution to obtain a reaction solution; adding an iodine compound, a rare earth compound, an alkali metal salt, an alkaline earth metal salt and red mud into the reaction solution in sequence to prepare a semi-finished product; and water and polyoxyethylene are mixed and distilled to obtain a diluent, the diluent is fully mixed with the semi-finished product, and finally sodium hydrosulfite and nano metal iron are added, so that the modification and activation effects on the coal-fired catalyst are synchronously completed, the solid waste is recycled, the harm of titanium white waste acid to the environment is reduced, and the production cost is reduced. Meanwhile, the coal-fired catalyst has the advantages of small addition amount, high coal saving rate, small smoke discharge amount, simple manufacturing process and wide application range.

Description

A kind of coal-fired catalyst produced by utilizing titanium dioxide waste acid and preparation method thereof

technical field

The invention belongs to the technical field of preparation of inorganic chemical materials, and more particularly relates to a coal-fired catalyst produced by utilizing titanium dioxide waste acid and a preparation method thereof.

Background technique

There are two major problems in the combustion and utilization of coal: one is insufficient coal combustion, large coal consumption, low thermal efficiency, and serious waste of coal resources; the other is that a large amount of soot, sulfur dioxide, carbon monoxide and other harmful gaseous substances are produced during the coal combustion process, which pollutes the atmosphere. In order to improve the utilization rate of coal resources, the traditional method is to improve the equipment and operation process, but its huge investment and complex process cannot fundamentally overcome the shortcomings of large slag output, high combustible content, and serious waste of coal resources.

In response to the above phenomenon, the common practice in the industry is to use coal-fired catalysts to promote coal-fired efficiency, which can not only increase the rate of coal volatilization analysis, reduce the ignition temperature of coal, shorten the ignition delay time, and accelerate the burnout rate of carbon, but also can solidify the Sulfur denitrification has huge economic and environmental benefits. However, the existing coal-fired catalysts are generally prepared from high-grade raw materials, which are relatively expensive and uneconomical, and the preparation process is complicated and time-consuming and labor-intensive.

After searching, the Chinese patent application number is: 212111172916.6, the application date is: March 13, 2121, and the name of the invention is: a coal-fired catalyst and its preparation method and application. The raw materials of the coal-fired catalyst disclosed in this application are: 11-13% inorganic acid, 3-6% catalytic component, 1.3-1.5% solid sulfur component and the balance of solvent, the catalytic component is selected from alkali metal oxides , one or more of transition metal oxides and rare earth metal oxides. The preparation method: adding the mineral acid into half of the solvent, mixing, adding the catalytic component and the solid sulfur component, stirring, and adding the balance of the solvent to obtain the coal-fired catalyst. This application improves the coal combustion rate and burnout rate by controlling the type and amount of coal-fired catalysts. However, the catalysts in this application have higher grades of raw materials, are more expensive to manufacture, and do not have the function of eliminating smoke. Soot is bigger.

SUMMARY OF THE INVENTION

1. The problem to be solved

Aiming at the above-mentioned problems in the production of existing conventional coal-fired catalysts, the present invention provides a coal-fired catalyst produced by utilizing titanium dioxide waste acid and a preparation method thereof, which not only effectively improves the flammability of coal, but also improves the coal-burning efficiency. , and simplifies the production process and cost of the existing common catalyst, and also solves the problem of disposal of titanium dioxide waste acid, which is beneficial to ecological environment protection and sustainable development.

2. Technical solutions

In order to solve the above problems, the technical scheme adopted in the present invention is as follows:

A coal-burning catalyst of the present invention is prepared by using titanium dioxide waste acid. The titanium dioxide waste acid is a waste acid solution produced in the preparation of titanium dioxide by a sulfuric acid method, which belongs to industrial hazardous waste and cannot promote coal combustion by itself. It is especially important to treat it in a suitable way so that it can significantly improve the combustion characteristics of coal. For example, the ferrous sulfate, titanium oxide, aluminum sulfate and some other useful metal elements (such as manganese, titanium, etc.) and rare earth elements (such as scandium, etc.) contained in it are processed to convert them into certain substances that promote the full combustion of coal. Other components that contribute to coal combustion, such as metal oxides or iron-containing compounds, are then sprayed in liquid form to adhere to the coal and play a role in the combustion of coal, further improving the efficiency of coal combustion. Specifically, the preparation method of the coal-fired catalyst of the present invention comprises the following steps:

Step 1. One or more combinations of low-grade copper oxide, sulfuric acid waste residue, and cuprous sulfide are pulverized and ground into powder, and the powder is added to the titanium dioxide waste acid solution. The speed of /min was stirred for 5145min to obtain a reaction solution whose main components were copper sulfate and ferric sulfate.

Step 2: Add iodide, rare earth compound, alkali metal salt, alkaline earth metal salt and red mud to the reaction solution obtained in step 1 at a normal temperature of 25° C. in sequence, and uniformly stir in a mixer at 211 r/min for 11 min to obtain a semi-finished product.

Step 3, take another 51L of tap water and 1.5% polyoxyethylene, stir and mix for 15min, add it into a distillation tank and distill it for 31min to prepare a smoke suppressant stock solution.

Step 4: Dilute the smoke suppressant stock solution in step 3 by 2/1000 and mix with the semi-finished product in step 2, then add a certain percentage of sodium hydrosulfite, and introduce a certain amount of nano-metal iron to uniformly mix.

As a further preference of the present invention, the sulfuric acid waste residue used in the present invention is sulfuric acid slag containing 41-61% Fe ₂ O ₃ , 15-25% FeO, 5-1% FeS, 5% CaO and 5% MgO, After mixing with titanium dioxide waste acid, it generates components that are easy to burn coal. The main reactions involved are as follows:

Fe ₂ O ₃ +3H ₂ SO ₄ →Fe ₂ (SO ₄ ) ₃ +3H ₂ O

CuO+H ₂ SO ₄ →CuSO ₄ +H ₂ O

Cu ₂ S+4H ₂ SO ₄ →2CuSO ₄ +S↓+2SO ₂ ↑+4H ₂ O

It should be noted that sulfuric acid waste residue, as an industrial hazardous waste, is mixed with titanium dioxide waste acid and finally made into a coal-fired catalyst, which is not only conducive to solving the problem of industrial waste landfill occupying a large area, high disposal costs, and environmental protection. The problem of large hidden dangers provides a new treatment idea for industrial waste and improves the utilization rate of resources. At the same time, it can also help reduce the production cost of the coal-fired catalyst, open up new varieties of the coal-fired catalyst, and be beneficial to ecological environment protection and sustainable development.

The titanium dioxide waste acid of the present invention is titanium dioxide waste sulfuric acid containing 11-22% H ₂ SO ₄ , 5-1% FeSO ₄ , 1-2% TiO ₂ , 1.5-2.5% Al ₂ (SO ₄ ) ₃ , the remaining components are inevitable impurities and water. In the preparation of coal-fired catalysts, it can fully react with related compounds. The main reactions involved are: TiO ₂ +H ₂ SO ₄ →TiOSO ₄ +H ₂ O, TiOSO ₄ +2H ₂ O→H ₂ TiO ₃ ↓+H ₂ SO ₄ , the metatitanic acid generated in the reaction process is unstable, but when it is put into the blast furnace, it will sinter with metal oxides, carbonates or metal halides at the high temperature of coal combustion to form compounds that contribute to coal combustion. Titanate to further improve the efficiency of coal combustion.

Preferably, the iodide is selected from alkali metal iodides, such as one or more of KI, NaI, and HI, and the mass percentage content of the iodide in the catalyst is 1.15-1%. The rare earth compound is selected from halides, nitrates or hydroxides of rare earth elements, such as RECl ₃ , RE(NO ₃ ) ₃ , RE(OH) ₃ , La(OH) ₃ , LaCl ₃ , Ce(NO ₃ ) One or more of ₃ , the mass percentage content of the rare earth compound in the catalyst is 1.5-5%. The alkali metal salt is selected from chlorides, carbonates, and nitrates of alkali metals, such as one or more of NaCl, Na ₂ CO ₃ , K ₂ CO ₃ , and NaNO ₃ , and the alkali metal salts are used in the catalyst. The content of the mass percentage is 1-15%. The alkaline earth metal salt is selected from chlorides and nitrates of alkaline earth metals, such as one or more of CaCl ₂ , MgCl ₂ , Mg(NO ₃ ) ₂ , Ca(NO ₃ ) ₂ , and the alkaline earth metal salt is in The mass percentage content in the catalyst is 1-21%. The red mud is Bayer process red mud containing 31% Fe ₂ O ₃ , which can not only fully desulfurize and fix sulfur, but also promote the combustion of coal, and the mass percentage content of the red mud in the catalyst is 1-11%.

In addition, the sodium dithionite added in the present invention refers to Na ₂ S ₂ O ₄ without crystal water, and its mass percentage content in the catalyst is 1-3%, which is easy to bleach impurities after adding. The added nano-metal iron refers to spherical nano-iron powder with a particle size of 51-71 nm, and its mass percentage content in the catalyst is 1-5%. Ferric sulfate generates ferrous sulfate, reacts with copper sulfate and generates nano-copper powder, so that the reaction occurs more fully, and the efficiency of the coal-fired catalyst is further improved. Among them, the main reaction formula involved is as follows:

Fe+Fe ₂ (SO ₄ ) ₃ →3FeSO ₄

Fe+CuSO ₄ →FeSO ₄ +Cu

More optimally, the nano-copper powder generated in the above reaction formula also helps to repair the worn parts of the blast furnace, which is beneficial to prolong the service life of the blast furnace equipment. The obtained coal-fired catalyst produced by the preparation method of the present invention fully utilizes industrial waste for production, the obtained coal-fired catalyst can effectively improve the coal-fired efficiency, and the preparation method is simple, easy and low in cost.

3. Beneficial effects

Compared with the prior art, the beneficial effects of the present invention are:

(1) the preparation method of a kind of coal-fired catalyst of the present invention, by adopting titanium dioxide waste acid and sulfuric acid waste residue for production, fully utilizes industrial waste, and realizes the recycling of titanium dioxide waste sulfuric acid by treating waste with waste, and compares The conventional disposal method of titanium dioxide waste acid is lower in cost and more environmentally friendly. At the same time, the present invention utilizes two kinds of industrial wastes to produce the coal-fired catalyst, which is more economical in cost, simple in process and remarkable in effect compared with the conventional method for preparing the coal-fired catalyst by using high-grade raw materials.

(2) The preparation method of a kind of coal-fired catalyst of the present invention, because titanium dioxide waste acid itself does not have the function of catalyzing coal combustion, the present invention preliminarily treats the titanium dioxide waste acid, so that the useful elements and components contained in it are generated. The reaction is converted into other components that contribute to the combustion of coal, which is used for coal combustion in blast furnaces, which effectively reduces the ignition point of coal and improves the efficiency of coal combustion.

(3) The preparation method of a coal-fired catalyst of the present invention is produced by adding titanium dioxide waste acid. Compared with the existing coal-fired catalyst preparation technology, the cost is lower, and it is convenient for mass production and wide application. More optimally, nano metal iron is also introduced into the catalyst component of the present invention, which can react with the main components in the catalyst under the high temperature formed by coal combustion, further promote the improvement of coal combustion efficiency, and the catalytic effect is better. , and its reaction products also help the blast furnace to repair the worn parts and prolong the service life of the blast furnace.

Detailed ways

The present invention will be further described below with reference to specific embodiments.

Example 1

A kind of coal-fired catalyst of the present embodiment, its preparation method is as follows:

Step 1, prepare reaction solution;

The combination of low-grade copper oxide and sulfuric acid waste residue is pulverized and ground into powder, and the powder is added to the titanium dioxide waste acid solution with a solid-liquid ratio of 3:7, and is stirred at a speed of 411r/min under the environment of 11°C. 31min.

Step 2. Preparation of semi-finished catalysts

It is prepared by dissolving the mass percentage of the following raw materials in the reaction solution and mixing them uniformly: NaI 1.5%; RECl ₃ 2%; CaCl ₂ 11%; red mud 3%; The semi-finished product was obtained by uniform stirring for 11 min.

Step 3. Preparation of finished catalyst

The diluted smoke suppressant prepared in the present invention is uniformly mixed with the above-mentioned semi-finished product, and 3% of sodium hydrosulfite and 2% of nano-Fe are added to the mixture.

Get the coal-fired catalyst gained in the present embodiment, its addition amount is 1.5%, fully mix with 211g cinder, put into the thermogravimetric analyzer (model is TGA/DSC1/1111SF) of the laboratory, the temperature increase range is 31-1211 ℃, The heating rate was 21°C/min, the temperature was linearly increased, the reaction atmosphere was oxygen, and the flow rate was 11 ml/min.

Implementation effect: the flammability of the fuel is improved, the ignition temperature of the coal is reduced by 31°C, the burnout rate of the coal is improved, and the coal burning is saved by 13%.

Example 2

A kind of coal-fired catalyst of the present embodiment, its preparation method is as follows:

Step 1, prepare reaction solution;

The combination of sulfuric acid waste residue and cuprous sulfide was pulverized and ground into powder, and the powder was added to the titanium dioxide waste acid solution with a solid-liquid ratio of 3:7, and was stirred at a speed of 451r/min for 45min under the environment of 11°C. .

Step 2. Preparation of semi-finished catalysts

It is prepared by dissolving the mass percentage of the following raw materials in the reaction solution and mixing them uniformly: KCl ₃ 1.7%; RE(OH) ₃ 3%; NaCl 11%; red mud 11%; the balance is the reaction solution and water. 211r/min uniform stirring for 11min to obtain semi-finished products.

Step 3. Preparation of finished catalyst

The diluted smoke suppressant prepared in the present invention is uniformly mixed with the above-mentioned semi-finished product, and 2% of sodium hydrosulfite and 3% of nano-Fe are added to the mixture.

Get the coal-fired catalyst gained in the present embodiment, its addition amount is 1.1%, fully mix with 211g cinder, put into the thermogravimetric analyzer (model is TGA/DSC1/1111SF) of the laboratory, the temperature increase range is 31-1211 ℃, The heating rate was 21°C/min, the temperature was linearly increased, the reaction atmosphere was oxygen, and the flow rate was 11 ml/min.

Implementation effect: the ignition temperature is reduced by 11°C, the combustion is stable, the amount of slag discharge is small, the concentration of soot is reduced, the coal burning is saved by 11%, and the emission of sulfur-containing waste gas is reduced by 75%.

Example 3

A kind of coal-fired catalyst of the present embodiment, its preparation method is as follows:

Step 1, prepare reaction solution;

The combination of low-grade copper oxide, sulfuric acid waste residue, and cuprous sulfide is pulverized and ground into powder, and the powder is added to the titanium dioxide waste acid solution with a solid-liquid ratio of 3:7. The speed was stirred for 41 min.

Step 2. Preparation of semi-finished catalysts

It is prepared by dissolving the mass percentage of the following raw materials in the reaction solution and mixing them uniformly: KI 1.5%; RE(NO ₃ ) ₃ 2%; Na ₂ CO ₃ 11%; MgCl ₂ 5%; red mud 2%; the remainder is the reaction Liquid and water were uniformly stirred in a mixer at 211r/min for 11min to obtain a semi-finished product.

Step 3. Preparation of finished catalyst

The diluted smoke suppressant prepared in the present invention is uniformly mixed with the above-mentioned semi-finished product, and 2% of sodium hydrosulfite and 1% of nano-Fe are added to the mixture.

Get the coal-fired catalyst gained in the present embodiment, its addition amount is 1.3%, fully mix with 211g coal slag, put into the thermogravimetric analyzer (model is TGA/DSC1/1111SF) of the laboratory, the temperature increase range is 31-1211 ℃, The heating rate was 21°C/min, the temperature was linearly increased, the reaction atmosphere was oxygen, and the flow rate was 11 ml/min.

Implementation effect: The coal burnout temperature is greatly reduced, the burnout time is shortened, the burnout effect is improved, the slag discharge is less, the _NOx emission is reduced by 12%, and the coal burning is saved by 14%.

Claims (10)

1. A preparation method of a coal-fired catalyst is characterized by comprising the following steps:

step one, crushing and grinding one or a combination of a plurality of low-grade copper oxide, sulfuric acid waste residue and cuprous sulfide into powder, adding the ground powder into a titanium white waste acid solution, and stirring to obtain a reaction solution;

step two, sequentially adding iodide, rare earth compound, alkali metal salt, alkaline earth metal salt and red mud into the reaction solution obtained in the step one, and stirring to obtain a semi-finished product;

stirring and mixing polyoxyethylene and water, and distilling to obtain a smoke suppressor stock solution;

and step four, diluting the smoke suppressor stock solution obtained in the step three, mixing the smoke suppressor stock solution with the semi-finished product obtained in the step two, and adding sodium hydrosulfite and nano metal iron to mix uniformly to obtain the smoke suppressor.

2. The method for preparing a coal-fired catalyst according to claim 1, wherein: in the first step, the stirring temperature is 10-80 ℃, the stirring speed is 150-450 r/min, the stirring time is 5-45 min, and the titanium white waste acid solution contains 18-22% of H₂SO₄、5-8％FeSO₄、1-2％TiO₂、1.5-2.5％Al₂(SO₄)₃The titanium white waste acid solution.

3. The method for preparing a coal-fired catalyst according to claim 1, wherein: in the second step, the first step is carried out,

the iodide is selected from alkali metal iodide, and the mass percent of the iodide in the catalyst is 0.05-1%;

the rare earth compound is selected from halide, nitrate or hydroxide of rare earth elements, and the mass percentage of the rare earth compound in the catalyst is 1.5-5%;

the alkali metal salt is selected from alkali metal chloride, carbonate and nitrate, and the mass percentage of the alkali metal salt in the catalyst is 0-15%;

the alkaline earth metal salt is selected from chlorides and nitrates of alkaline earth metals, and the mass percentage content of the alkaline earth metal salt in the catalyst is 0-20%; .

4. The method for preparing a coal-fired catalyst according to claim 3, characterized in that: the iodide adopts one or more of KI, NaI and HI; the rare earth compound adopts RECl₃、RE(NO₃)₃、RE(OH)₃、La(OH)₃、LaCl₃、Ce(NO₃)₃One or more of (a).

5. The method for preparing a coal-fired catalyst according to claim 3, characterized in that: the alkali metal salt adopts NaCl and Na₂CO₃、K₂CO₃、NaNO₃One or more of; the alkaline earth metal salt adopts CaCl₂、MgCl₂、Mg(NO₃)₂、Ca(NO₃)₂One or more of (a).

6. The method for producing a coal-fired catalyst according to any one of claims 1 to 5, whereinThe method comprises the following steps: the waste sulfuric acid residue contains 40-60% of Fe₂O₃15-25% of FeO, 5-8% of FeS, 5% of CaO and 5% of MgO.

7. The method for producing a coal-fired catalyst according to any one of claims 1 to 5, wherein: the red mud contains 30 percent of Fe₂O₃The Bayer process red mud has the mass percentage content of 1-10% in the catalyst.

8. The method for producing a coal-fired catalyst according to any one of claims 1 to 5, wherein: the sodium hydrosulfite is Na without crystal water₂S₂O₄The mass percentage content of the catalyst is 1-3%.

9. The method for producing a coal-fired catalyst according to any one of claims 1 to 5, wherein: the particle size of the nano metallic iron is 50-70nm, and the mass percentage content of the nano metallic iron in the catalyst is 1-5%.

10. A coal-fired catalyst characterized by: prepared by the preparation method as described in any one of claims 1 to 9.