A kind of composite slow-corrosion scale resistor that is used for severe corrosive water quality
The present invention relates to corrosion inhibiting and descaling agent, more specifically saying so is used for the composite slow-corrosion scale resistor of severe corrosive water quality.
The Industrial Boiler water and the technological process water of industries such as petrochemical industry, electric power, beverage, filature, sensitive film, not only water consumption is big, and to the water quality requirement height, must just can obtain qualified water quality by softening, desalting treatment.In order to reach above-mentioned requirements, adopt electrodialysis process usually, but this method is when making pure water, also produce the dense water of a large amount of by product-severe corrosives, in the dense water enrichment ion of strict restriction in a large amount of technic indexs, as Ca
2+, SO
4 2-, Cl
-, HCO
3 -Deng, water quality is very abominable, and is all more serious to corrosion of Carbon Steel and the fouling on heat-transfer surface, and the difficulty of Li Yonging is very big again.Most factories directly discharge, and cause the waste of water resources, and the dense water recirculating process of the employing that also has has improved the dense water rate of recovery, but also have nearly 30% dense water to discharge, and still are not basic outlets that solves dense water reuse.Meanwhile, industries such as petrochemical complex, thermal power generation, metallurgy need a large amount of recirculated cooling waters, and for example, petroleum chemical enterprise's cooling water accounts for 60~80% of total water amount.If this part water all adopts fresh water, can aggravate the nervous situation of China's water resources undoubtedly.Otherwise, if the dense water of above-mentioned severe corrosive is back to recirculating cooling water system, then both can reduce the effluent charge usefulness of dense water, can save a large amount of fresh waters again, be to kill two birds with one stone, the protection water resources is had important practical significance.
Because industrial dense water water quality is very abominable, must add special water conditioner could utilize.
Up to now, yet there are no the water conditioner that report is used for the dense water of severe corrosive in the domestic and foreign literature.In " industrial colling treatment process " book of Xu Shouchang chief editor in 1989, propose to handle super-low-hardness water quality, but chromic salt toxicity is big, contaminate environment with chromic salt or chromic salt/zinc treatment agent.Mccoy Jw, " Thechemical treatment of cooling water " (NALCO, 1974) propose a kind of organic phospho acid/phosphoric acid salt/poly-phosphate prescription, are applicable to super-low-hardness water quality.When practical application should be filled a prescription,, need replenish the calcium, reduce pH value for the precipitation that prevents calcium phosphate scale also needs acidifying in order to reach corrosion mitigating effect preferably.The phosphorus content of should filling a prescription in addition is higher, easily causes the eutrophic pollution of water body.USP 4,717, and 542 have reported the prescription of dihydroxyl phosphino-acetate (HPAA)/polymkeric substance, can be used for handling the water quality that hardness is 80mg/L.At " Anew totalorganic approach for the control of corrotion and deposition in cooling-water systems " (CorrotionPrevention ﹠amp; Control, (12) 159~162,1987) propose a kind of hydroxyl phosphoric acid/cationoid polymerisation composition formula in the article, can handle the water quality of calcium hardness, but dosing is up to 100~150mg/L greater than 25mg/L, in addition, USP 4,649, and 025 HPAA/HEDP (1-Hydroxy Ethylidene-1,1-Diphosphonic Acid)/TTA (toluene triazole) prescription of introducing also can be handled the circulating water system that hardness is 80mg/L, but erosion rate is higher, is about 0.142mm/a.
The objective of the invention is to based on prior art, overcome its defective, a kind of low toxicity, low-phosphorous, easy to use is provided, be applicable to the composite slow-corrosion scale resistor of severe corrosive water quality.
Another object of the present invention is to provide a kind of method that the dense water of severe corrosive industry is back to recirculating cooling water system.
Composite slow-corrosion scale resistor provided by the invention (calling recombiner in the following text) prescription comprises hydroxyl phosphino-acetic acid compound, organic phospho acid compound, phosphine carboxylic acid cpd and zinc salt, its component concentration (is benchmark with the composition weight): hydroxyl phosphino-acetic acid compound 10~30%, be preferably 12~27%, organic phospho acid compound 5~15%, be preferably 6~13%, phosphine carboxylic acid cpd 5~15%, be preferably 6~13%, zinc salt 5~12%, all the other are water.
Recombiner of the present invention can also contain nitrogen azole material, and its content is 0.5~2.0%.
Described hydroxyl phosphino-acetic acid compound can be 2-hydroxyl phosphino-acetate (HPAA) or its sylvite (HPAAK), sodium salt (HPAANa), ammonium salt (HPAANH
4) or the mixture of above-mentioned substance, this compounds has excellent corrosion mitigating effect, is host of the present invention.
Described organic phospho acid compound is selected from ethylene diamine tetra methylene phosphonic acid (CEDTMP), 1-Hydroxy Ethylidene-1,1-Diphosphonic Acid (HEDP), Amino Trimethylene Phosphonic Acid (ATMP), or their sylvite (EDTMPK, HEDPK, ATMPK), Na salt (EDTMPNa, HEDPNa, ATMPNa) and ammonium salt (EDTMPNH
4, HEDPNH
4, ATMPNH
4) or the mixture of above-mentioned substance, this compounds has the corrosion-mitigation scale-inhibition effect, during particularly with the compound use of other corrosion inhibiting and descaling agent, has remarkable role in synergy.
Described phosphine carboxylic acid cpd comprises 2-phosphono-containing butane-1,2,4-tricarboxylic acid (PBTC), or its sylvite (PBTCK) sodium salt (PBTCNa) and ammonium salt (PBTCNH
4) or the mixture of above material, this compounds has inhibition CaCO
3The performance of fouling has steady zinc, corrosion inhibition simultaneously concurrently.
Described zinc salt is selected from zinc chloride or zinc sulfate.Zinc salt is a kind of inhibiter commonly used, usually will with the compound use of other inhibiter, play corrosion mitigating effect by generating precipitation membrane at heat-transfer surface.
Described nitrogen azole material is selected from benzotriazole (BTA) or methyl-benzotriazole (TTA).This class material is a copper inhibitor, is applicable to the circulating water system of using the copper interchanger.
Above-mentioned classes of compounds is the commercial goods.
Recombiner of the present invention is prepared as follows: take by weighing each component at normal temperatures in proportion, earlier zinc salt is added in the phosphine carboxylic acid cpd, fully stir, after waiting to dissolve, add hydroxyl phosphino-acetic acid compound, organic phospho acid compound and distilled water again.Add nitrogen azole material as need, can earlier it be dissolved in the distilled water, add with distilled water again.
Recombiner of the present invention is applicable to the dense water of severe corrosive.As the dense water of electrodialysis, wherein Cl
-And SO
4 2-Total content is 500~1000mg/L, Ca
2+Content is (with CaCO
3Meter) be 20~120mg/L.
Recombiner of the present invention is added in the dense water of corrodibility industry, can make it be back to recirculating cooling water system.Concrete operations are: carry out the pre-film of routine at the initial stage heat exchanging device of driving and handle, method is to add Sodium hexametaphosphate 99 120mg/L, Zn in pre-film water matter
2+20mg/L, transfer PH5.7~6.5, move 48~72 hours continuously after, finish pre-film, the pre-film water matter of emptying is introduced the industrial dense water that has added recombiner of the present invention, changes normal operation over to.The concentration of recombiner of the present invention in dense water should be controlled at 35~65mg/L, and pre-film water matter can be fresh water, also can be dense water.
Composite slow-corrosion scale resistor of the present invention has following advantage: (1) is owing to select for use the various ingredients that comprises 2-hydroxyl phosphino-acetate class high-efficient corrosion inhibitor and organic phosphine carboxylic acid class Scale inhibitors composite, make this recombiner can be than producing good inhibition and scale inhibition effect under the few additive, as reaching 0.026mm/a, adhere to speed less than 5.045mg/cm to corrosion of carbon steel speed
2Mon; (2) recombiner of the present invention does not contain inorganic phosphate, and phosphorus content is low, can prevent the calcium phosphate scale precipitation, reduces water eutrophication and pollutes.Recombiner does not contain and poisons compound such as chromic salt in addition, more helps environment protection; When (3) adopting recombiner of the present invention to handle the dense water of severe corrosive, do not need dense water is carried out pre-treatment, do not replenish the calcium, uncomfortable pH value does not increase equipment, and is easy and simple to handle; (4) by adopting recombiner of the present invention, can make the dense water of severe corrosive industry be back to circulating water system, not only can reduce the dirty expense of concentrated water drainage, can also save a large amount of fresh waters, the protection water resources is had important practical significance.
Further specify characteristics of the present invention below by embodiment.
Example 1
This example adopts carbon steel to carry out corrosion test.
The preparation of recombiner: earlier with 7g ZnCl
2(the Wujin Fine Chemical Works is produced to join 8g PBTC solution, concentration 40%) in, (the emerging magnificent water quality stabilizer in Beijing factory produces to add 7g HEDP (Tianjin chemical research institute, concentration is 50%) and 15g HPAA after the dissolving again, concentration 40%), add the 63g deionized water at last.
Antisludging test: with reference to the HG/T2024-91 method, preparation Ca
+, HCO
3 2-Be the test water quality of 250mg/L, Xiang Shuizhong adds above-mentioned recombiner, consumption 50mg/L, and spontaneous evaporation is 10 hours under the water bath with thermostatic control, makes test solution concentrate 2 times, with doing blank test.Test solution is filtered the Ca in the assay determination clear liquor
2+Content, Ca before and after will testing
2+Ca in content and the blank test solution
2+Content contrasts, and the scale inhibition performance that calculates medicament is 96.80%.
Corrosion inhibition test: with reference to the HG/T2159-91 standard, the above-mentioned recombiner that adds 50mg/L in the dense at the scene water (Cangzhou Refinery heat power plant, water quality data is seen attached list) is made into test solution, 40 ℃ of control test solution temperature, and test piece is 20
#Standard carbon steel lacing film, its surface-area are 0.28dm
2, the test piece rotating speed is 75 rev/mins, about 0.35 meter per second of rotational line speed moves 96 hours continuously.After the off-test, take out test piece, cleaning, drying, calculating corrosion inhibition rate by changes in weight before and after the test is 87.92%.
Example 2
This example adopts carbon steel to carry out corrosion test.
The preparation of recombiner: earlier with 9g ZnSO
4Join 10g PBTCNH
4In the solution, add 9g HEDPK and 20g HPAAK after the dissolving again, add 52g distilled water at last.
Antisludging test: method is with example 1, and recombiner concentration is 45mg/L, records scale inhibition performance 98.96%.
Corrosion inhibition test: method is with example 1, and recombiner concentration is 45mg/L, records corrosion inhibition rate (99.89%).
Example 3
This example adopts carbon steel to carry out corrosion test.
The preparation of recombiner: with 11g ZnCl
2Join in the 12g PBTCK solution, add 12g EDIMPNH after the dissolving again
4With 25g HPAANa, add 50g distilled water at last.
Antisludging test: method is with example 1, recombiner consumption 60mg/L, and recording scale inhibition performance is 97.92%.
Corrosion inhibition test: method is with example 1, and recombiner consumption 60mg/L records corrosion inhibition rate 93.40%.
Example 4
This example adopts red copper to carry out corrosion test.
The preparation of recombiner: with 8.3g ZnSO
4Join in the 10g PBTC solution, add 9gATMP and 20g HPAA after the dissolving again, add the 53g distilled water that has dissolved 0.7g BTA at last.
Antisludging test: method is with example 1, and recombiner consumption 50mg/L calculates scale inhibition performance 98.24%.
Corrosion inhibition test: method is with example 1, but lacing film is the red copper lacing film, and surface-area also is 0.28dm
2, recording corrosion inhibition rate after the experiment is 99.71%.
Example 5
This example adopts red copper to corrode examination.
The preparation of recombiner: with 10 ZnCl
2Join in the 12g PBTCNa solution, add 11.4gHEDPNa and 24g HPAANH after the dissolving again
4, the last 41g distilled water that has dissolved 1.6g TTA that adds again.
Antisludging test: method is with example 1, recombiner consumption, 40mg/L, scale inhibition performance: 99.02%.
Corrosion inhibition test: method is with example 4, recombiner consumption 40mg/L, corrosion inhibition rate: 99.11%.
Example 6
This example is a dynamic analog test:
With reference to HG/T2160-91 standard " water coolant dynamic simulation experiment method ", test water quality is on-the-spot dense water (with example 1), and recombiner adopts the prescription of example 2, and the heat exchange test tube is by 20
#Carbon steel is made, length 710mm, and wall thickness 1mm, internal diameter 8mm, circulating water flow 1m/s, 32 ℃ of test tube temperature ins, 42 ℃ of temperature outs are moved 15 days continuously.Record erosion rate 0.026mm/a, adhere to speed 0.45mg/cm
2Mon.
Example 7
This example is a Comparative Examples.
Adopt the method for example 6 to carry out dynamic analog test, do not add recombiner, record erosion rate 0.450mm/a, adhere to speed 37.46mg/cm
2Mon.
By Comparative Examples explanation, adopt recombiner of the present invention can significantly reduce the corrosion and the scaling rate of the dense water of severe corrosive, make it can Secure Application in recirculating cooling water system.
The main water quality data of the on-the-spot dense water of subordinate list
The menu bit data
PH 8.63
Ca
2+(with CaCO
3Meter) mg/L 43.84
HCO
3 - mg/L 502.72
Cl
- mg/L 562.52
SO
4 2- mg/L 240.0
Electricity is led um/cm 1397
K
+ mg/L 1.6