CN103880041B - A kind ofly combine the method that embrane method refines thiocyanate- - Google Patents
A kind ofly combine the method that embrane method refines thiocyanate- Download PDFInfo
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- CN103880041B CN103880041B CN201410084853.8A CN201410084853A CN103880041B CN 103880041 B CN103880041 B CN 103880041B CN 201410084853 A CN201410084853 A CN 201410084853A CN 103880041 B CN103880041 B CN 103880041B
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Abstract
The invention discloses and a kind ofly combine the method that embrane method refines thiocyanate-, belong to Chemicals purification field, the ammonium thiocyanate of different purity or Sodium Thiocyanate 99 solid are made certain density initial aqueous solution, and utilizes dissolubility difference to control the total concn of dianion salt in initial aqueous solution within certain limit; By the initial aqueous solution of gained respectively through activated carbon decolorizing process, microfiltration membrane process, ultrafiltration membrane treatment and multistage nanofiltration membrane treatment, remove the impurity such as coloring matter, suspended particle, macromolecular substance, dianion salt in solution respectively, final nanofiltration permeate is the highly purified thiocyanate-aqueous solution.This aqueous solution concentrated, can obtain high-quality, highly purified thiocyanate-product.Nanofiltration condensed water through enrichment process, then returns initial aqueous solution and recycles.The present invention is simple to operation, mild condition, does not have particular requirement to technology and equipment, versatility and suitability strong.
Description
Technical field
The present invention relates to a kind of thiocyanate-method for purification based on combined films technology.Be specially adapted to the refining thiocyanate-product carried salt and obtain from desulphurization waste liquid of coke oven gas.Belong to Chemicals purification field.
Background technology
Thiocyanate-series product, comprising Sodium Thiocyanate 99, ammonium thiocyanate, potassium sulfocyanate etc. is the important basic chemical industry raw material of a class, be widely used in polymer to reel off raw silk from cocoons the manufacturing field of the products such as solvent, antimildew and antibacterial product, concrete admixture and agricultural chemicals, medicine, dyestuff, have the great market requirement.And from the desulphurization waste liquid of coke oven gas of coal chemical enterprise, extract corresponding thiocyanate-product day by day become the topmost production technique of these series product, original employing sodium cyanide or dithiocarbonic anhydride are that the chemical synthesis process of raw material is by atrophy day by day.Domestic have numerous correlation technique reports.
Desulphurization waste liquid of coke oven gas itself is a kind of high salt, high pollution system of forming complexity, except the inorganicss such as thiocyanate-, thiosulphate, vitriol, free ammonia, free alkali, heavy metal ion, elemental sulfur, also containing all kinds of organic substances produced in remainder catalyst and process of coking.No matter adopt any existing purifying technique, carry thiocyanate-product that salt obtains and all contain all kinds of impurity more or less.Both affect the indices such as the purity of product, outward appearance, also have impact on the result of use of downstream user.Therefore, be necessary to develop a kind of thiocyanate-purifying technique efficiently, to improve the quality that desulphurization waste liquid of coke oven gas carries product salt, meet the demand of all types of user to product quality.
Summary of the invention
The technical issues that need to address of the present invention are just the defect overcoming prior art, and provide a kind of and combine the method that embrane method refines thiocyanate-, it is simple to operation, mild condition, does not have particular requirement to technology and equipment, versatility and suitability strong.
For solving the problem, the present invention adopts following technical scheme:
The invention provides and a kind ofly combine the method that embrane method refines thiocyanate-, described method comprises the following steps:
1), refining thiocyanate-solid phase prod will be treated through initial gross separation, be mixed with the aqueous solution; In the aqueous solution, the weight concentration of thiocyanate-is 30-60%; In solution, the weight total content of all kinds of dianion salt controls within 10%;
2), the aqueous solution configured is filtered through the plate-and-frame filter press with microfiltration membrane;
3), the solution through microfiltration membrane process is carried out uf processing;
4), by the solution through uf processing carry out one-level nanofiltration process, through one-level nanofiltration operation the weight total content through solution dianion salt lower than 3000ppm;
5), by one-level nanofiltration solution again through secondary nanofiltration process, secondary nanofiltration is below 300ppm through the dianion salt total concentration by weight of solution;
6), by the permeate of secondary nanofiltration concentrate, crystal filters after separating out, and obtain the thiocyanate-product of high-quality, purity reaches more than 99%.
In the inventive method, preferably, the aqueous solution prepared for step 1) adopts gac to decolour to it.
In the inventive method, microfiltration membrane is 0.27 micron of microfiltration membrane.
In the inventive method, the condition of uf processing is: ultra-filtration membrane adopts other ultra-filtration membranes of hollow fiber ultrafiltration membrane or identical function, temperature 5-45 DEG C, pressure is 0.5-2.5bar, the pH value of water inlet is 4-12.
In the inventive method, the condition of one-level nanofiltration process is: temperature 5-45 DEG C, pressure is 15-35bar, the pH value of water inlet is 4-12.
Further preferably, in the inventive method, the condition of one-level nanofiltration process is: temperature 25-35 DEG C, pressure is 20-30bar, the pH value of water inlet is 5-9; Nanofiltration membrane adopts organic rolling composite nanometer filtering film.
In the inventive method, the condition of secondary nanofiltration process is: temperature 5-45 DEG C, pressure is 15-35bar, the pH value of water inlet is 4-12.
Further preferably, in the inventive method, the condition of secondary nanofiltration process is: temperature 25-35 DEG C, pressure is 10-20bar, the pH value of water inlet is 5-9; Nanofiltration membrane adopts organic rolling composite nanometer filtering film.
In the inventive method, firsts and seconds nanofiltration condensed water is concentrated or dissolved solids thiocyanate-enrichment process through heating, then returns initial aqueous solution and recycle.
The present invention has the following advantages:
1, simple to operation, mild condition, does not have particular requirement to technology and equipment, versatility and suitability strong.
2, adopt pure physical method thoroughly to remove the various impurity such as suspended particle, macromole, coloured molecule, dianion salt, do not introduce new impurity, do not cause secondary pollution; Gained thiocyanate-excellent product quality.
3, this technique is easy to realize intelligent control and automated operation.
Embodiment
embodiment 1
1, the ammonium thiocyanate that provides of certain enterprise, outward appearance is off-white color, content 96.5%, wherein ammonium sulphate content 2.3%.By the deionized water dissolving of 500 kilograms of these products with 500 liters, obtain the subdiaphanous aqueous solution.After testing, in this solution, ammonium thiocyanate content is 48.5%, and ammonium sulphate content is 1.1%.
2, above-mentioned solution is filtered through the plate-and-frame filter press posting 0.27 micron of microfiltration membrane, removing suspended particle impurity.
3, above-mentioned permeate is used ultrafiltration membrane treatment further, remove more tiny impurity particle and macromole solute.Filtered liquid clear, meets the water inlet standard of nanofiltration operation.The processing condition of uf processing are: ultra-filtration membrane adopts other ultra-filtration membranes of hollow fiber ultrafiltration membrane or identical function, temperature 5-45 DEG C, pressure is 0.5-2.5bar, the pH value of water inlet is 4-12.
4, the solution through uf processing is carried out nanofiltration process.The processing condition of nanofiltration process are: temperature 5-45 DEG C, pressure is 15-35bar, the pH value of water inlet is 4-12; The processing condition of preferred nanofiltration process are: temperature 25-35 DEG C, pressure is 20-30bar, the pH value of water inlet is 5-9; Nanofiltration membrane adopts organic rolling composite nanometer filtering film.Nanofiltration permeate 400 kilograms is obtained after operation.After testing, in permeate, ammonium thiocyanate content is 49.2%, and ammonium sulfate is 800ppm.Nanofiltration operates the dianion salt that effectively removes in solution, and the complete clear of solution, shows that a small amount of foreign pigment is removed simultaneously simultaneously.
5, as having higher requirement to quality product, secondary nanofiltration can be carried out to above-mentioned permeate, the processing condition of secondary nanofiltration are same as described above, and the processing condition of preferred secondary nanofiltration process are: temperature 25-35 DEG C, pressure is 10-20bar, the pH value of water inlet is 5-9; Nanofiltration membrane adopts organic rolling composite nanometer filtering film.200 kilograms of one-level nanofiltration permeate are carried out secondary nanofiltration operation, obtains secondary nanofiltration permeate 160 kilograms.
6, the permeate of one-level nanofiltration or secondary nanofiltration concentrated, crystal filters after separating out, and can obtain the ammonium thiocyanate product of high-quality, purity can reach more than 99%.Concentrated one-level nanofiltration permeate, in gained ammonium thiocyanate, ammonium sulphate content is lower than 400ppm; Concentrated secondary nanofiltration permeate, in gained ammonium thiocyanate, ammonium sulphate content is lower than 100ppm.
7, in the present embodiment, consisting of of typical one-level or secondary nanofiltration concentrated solution, ammonium thiocyanate 50%, ammonium sulfate 8%.Get 100 kilograms of above-mentioned concentrated solutions, heating boils off 20 kg of water, has ammonia sulfate crystal to separate out, obtain about 5 kilograms of ammonia sulfate crystals and 75 kilograms of filtrates after filtration after cooling.Filtrate is composed as follows: ammonium thiocyanate 65%, ammonium sulfate 4%; Add 20 kilograms of deionized waters and dilute above-mentioned filtrate, obtain 95 kg of solution, composed as follows: ammonium thiocyanate 51%, ammonium sulfate 3%, can be incorporated to initial soln and repeat aforesaid operations flow process 2-6.
8, additive method process nanofiltration concentrated solution can also be adopted.100 kilograms of identical nanofiltration concentrated solutions, add 30 kilograms of pending ammonium thiocyanate solids, are heated to 70 DEG C, solid is all dissolved; There is ammonia sulfate crystal to separate out after being cooled to room temperature, obtain 5 kilograms of ammonium sulfate solids and 125 kilograms of filtrates after filtering.Filtrate is composed as follows: ammonium thiocyanate 64%, ammonium sulfate 4%; Add 30 kilograms of deionized waters and dilute above-mentioned filtrate, obtain 95 kg of solution, composed as follows: ammonium thiocyanate 51%, ammonium sulfate 3%, can be incorporated to initial soln and repeat aforesaid operations flow process 2-6.
embodiment 2
1, the ammonium thiocyanate that provides of certain enterprise, outward appearance is blackish green, content 75%, wherein ammonium sulphate content 20%, ammonium thiosulfate content 3%.In 500 kilograms of these products, add 200 liters of deionized waters, be warming up to 70 DEG C, make dissolution of solid as much as possible.After being cooled to room temperature, filtering, obtain blackish green crystal and 600 kilograms of blackish green filtrates of 100 kilograms of liquid containing ammonium sulfates and ammonium thiosulfate.Add 3 kilograms of gacs in filtrate and carry out decolorization operations, obtain 600 kilograms of light green filtrates, after testing, composed as follows, ammonium thiocyanate 62%, ammonium sulfate 4%, ammonium thiosulfate 2.5%.Add 100 kilograms of deionized waters and dilute above-mentioned filtrate, obtain 700 kg of solution, composed as follows: ammonium thiocyanate 52%, ammonium sulfate 3%, ammonium thiosulfate 2%.
2, above-mentioned solution is carried out combined films purification operations by the 2-6 bar of embodiment 1, can obtain ammonium thiocyanate solution or the ammonium thiocyanate crystal of removing dianion salt, nanofiltration concentrated solution can carry out reuse operation according to the 7-8 bar of embodiment 1.
embodiment 3
1, the Sodium Thiocyanate 99 that provides of certain enterprise, outward appearance is off-white color, content 95.7%, wherein sodium sulphate content 2.1%, and sodium thiosulfate content is 0.9%.By the deionized water dissolving of 500 kilograms of these products with 500 liters, obtain the subdiaphanous aqueous solution.After testing, in this solution, Sodium Thiocyanate 99 content is 48.0%, and sodium sulphate content is 1.1%, and sodium thiosulfate content is 0.6%.
2, above-mentioned solution is carried out combined films purification operations by the 2-6 bar of embodiment 1, can obtain sodium thiocyanate solution or the Sodium Thiocyanate 99 crystal of removing dianion salt, nanofiltration concentrated solution can carry out reuse operation according to the 7-8 bar of embodiment 1.
embodiment 4
1, the Sodium Thiocyanate 99 that provides of certain enterprise, outward appearance is blackish green, content 60%, wherein sodium sulphate content 30%, sodium thiosulfate content 3%.In 500 kilograms of these products, add 160 liters of deionized waters, be warming up to 70 DEG C, make dissolution of solid as much as possible.After being cooled to room temperature, filtering, obtain blackish green crystal and 520 kilograms of blackish green filtrates of 140 kilograms of contains sodium sulfate and Sulfothiorine.Add 3 kilograms of gacs in filtrate and carry out decolorization operations, obtain 520 kilograms of light green filtrates.After testing, composed as follows, Sodium Thiocyanate 99 55%, sodium sulfate 4%, Sulfothiorine 1.5%.
2, above-mentioned solution is carried out combined films purification operations by the 2-6 bar of embodiment 1, can obtain sodium thiocyanate solution or the Sodium Thiocyanate 99 crystal of removing dianion salt, nanofiltration concentrated solution can carry out reuse operation according to the 7-8 bar of embodiment 1.
Last it is noted that obviously, above-described embodiment is only for example of the present invention is clearly described, and the restriction not to embodiment.For those of ordinary skill in the field, can also make other changes in different forms on the basis of the above description.Here exhaustive without the need to also giving all embodiments.And thus the apparent change of amplifying out or variation be still among protection scope of the present invention.
Claims (1)
1. combine the method that embrane method refines thiocyanate-, it is characterized in that, described thiocyanate-is from desulphurization waste liquid of coke oven gas, carry the thiocyanate-that salt obtains, and this thiocyanate-is ammonium thiocyanate, and described method comprises the following steps:
(1) ammonium thiocyanate to be refined is got, outward appearance is off-white color, ammonium thiocyanate content is 96.5%, wherein ammonium sulphate content is 2.3%, by 500 kilograms of these ammonium thiocyanates to be refined deionized water dissolving of 500 liters, obtain the subdiaphanous aqueous solution, after testing, in this solution, ammonium thiocyanate content is 48.5%, and ammonium sulphate content is 1.1%;
(2) above-mentioned solution is filtered through the plate-and-frame filter press posting 0.27 micron of microfiltration membrane, removing suspended particle impurity;
(3) permeate is used ultrafiltration membrane treatment further, remove more tiny impurity particle and macromole solute, filtered liquid clear, meet the water inlet standard of nanofiltration operation, the processing condition of uf processing are: ultra-filtration membrane adopts hollow fiber ultrafiltration membrane, temperature 5-45 DEG C, pressure is 0.5-2.5bar, the pH value of water inlet is 4-12;
(4) solution through uf processing is carried out nanofiltration process, the processing condition of nanofiltration process are: temperature 25-35 DEG C, pressure is 20-30bar, the pH value of water inlet is 5-9; Nanofiltration membrane adopts organic rolling composite nanometer filtering film, nanofiltration permeate 400 kilograms is obtained after operation, after testing, in permeate, ammonium thiocyanate content is 49.2%, ammonium sulfate is 800ppm, nanofiltration operates the dianion salt that effectively removes in solution, and the complete clear of solution, shows that a small amount of foreign pigment is removed simultaneously simultaneously;
(5) carry out secondary nanofiltration to above-mentioned permeate, the processing condition of secondary nanofiltration process are: temperature 25-35 DEG C, pressure is 10-20bar, the pH value of water inlet is 5-9; Nanofiltration membrane adopts organic rolling composite nanometer filtering film, 200 kilograms of one-level nanofiltration permeate is carried out secondary nanofiltration operation, obtains secondary nanofiltration permeate 160 kilograms;
(6) permeate of one-level nanofiltration or secondary nanofiltration concentrated, crystal filters after separating out, and can obtain the ammonium thiocyanate product of high-quality, purity is more than 99%; Wherein concentrated one-level nanofiltration permeate, in gained ammonium thiocyanate, ammonium sulphate content is lower than 400ppm; Concentrated secondary nanofiltration permeate, in gained ammonium thiocyanate, ammonium sulphate content is lower than 100ppm;
Wherein, consisting of of described one-level or secondary nanofiltration concentrated solution, ammonium thiocyanate 50%, ammonium sulfate 8%; Get 100 kilograms of above-mentioned concentrated solutions, heating boils off 20 kg of water, and have ammonia sulfate crystal to separate out after cooling, obtain about 5 kilograms of ammonia sulfate crystals and 75 kilograms of filtrates after filtration, filtrate is composed as follows: ammonium thiocyanate 65%, ammonium sulfate 4%; Add 20 kilograms of deionized waters and dilute above-mentioned filtrate, obtain 95 kg of solution, composed as follows: ammonium thiocyanate 51%, ammonium sulfate 3%, can be incorporated to initial soln and repeat aforesaid operations flow process 2-6; Or, to 100 kilograms of identical nanofiltration concentrated solutions, add 30 kilograms of pending ammonium thiocyanate solids, be heated to 70 DEG C, solid is all dissolved; Have ammonia sulfate crystal to separate out after being cooled to room temperature, obtain 5 kilograms of ammonium sulfate solids and 125 kilograms of filtrates after filtering, filtrate is composed as follows: ammonium thiocyanate 64%, ammonium sulfate 4%; Add 30 kilograms of deionized waters and dilute above-mentioned filtrate, obtain 95 kg of solution, composed as follows: ammonium thiocyanate 51%, ammonium sulfate 3%, can be incorporated to initial soln and repeat aforesaid operations flow process 2-6.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN109796030A (en) * | 2019-03-22 | 2019-05-24 | 扬州康龙环保工程有限公司 | A kind of method of the ammonium thiocyanate, the purification of sodium sulfocyanate product that are extracted in coking desulfurization waste liquor |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105621456A (en) * | 2016-03-24 | 2016-06-01 | 上海膜净水处理工程有限公司 | Purification recycling method and device for sodium thiocyanate solution in two-step method acrylic fiber production |
| CN112978993B (en) * | 2021-02-25 | 2022-03-18 | 宜昌东阳光生化制药有限公司 | Method for recovering thiocyanate ions from rectification waste liquid of erythromycin thiocyanate crystallization mother liquor and application |
| CN115382290A (en) * | 2021-05-24 | 2022-11-25 | 蓝星工程有限公司 | Purification process of sodium thiocyanate solution |
| CN113716778A (en) * | 2021-09-01 | 2021-11-30 | 清创人和生态工程技术有限公司 | Zero-emission treatment method for secondary salt produced by coke oven gas desulfurization waste liquid |
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| CN101182009A (en) * | 2007-10-31 | 2008-05-21 | 扬州澄露环境工程有限公司 | Purification recovering method for sodium thiocyanate solution of acrylic fiber production |
| CN103397212A (en) * | 2013-08-05 | 2013-11-20 | 江苏久吾高科技股份有限公司 | Membrane technology-based ionic rare earth ore extraction technology and device therefor |
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| CN101182009A (en) * | 2007-10-31 | 2008-05-21 | 扬州澄露环境工程有限公司 | Purification recovering method for sodium thiocyanate solution of acrylic fiber production |
| CN103397212A (en) * | 2013-08-05 | 2013-11-20 | 江苏久吾高科技股份有限公司 | Membrane technology-based ionic rare earth ore extraction technology and device therefor |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN109796030A (en) * | 2019-03-22 | 2019-05-24 | 扬州康龙环保工程有限公司 | A kind of method of the ammonium thiocyanate, the purification of sodium sulfocyanate product that are extracted in coking desulfurization waste liquor |
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