A kind of production technology of high-quality sodium thiocyanate

Abstract

The invention discloses a production process of high-quality sodium thiocyanate and belongs to the technical field of compound production. The production process comprises the following steps: A, introducing air or oxygen into an ammonia-soda process coking desulfuration waste liquid, and performing oxidation treatment on the waste liquid; B, decoloring the material liquid oxidized in the step A;C, putting sodium hydroxide into the material liquid decolored in the step B, and carrying out ammonia removal treatment; D, cooling the material liquid after ammonia removal treatment in the step C,keeping the temperature to carry out crystal separation, and filtering to obtain a sodium thiocyanate solution; E, filtering the cooled sodium thiocyanate solution after crystal separation by using anano filter membrane filtering system; F, concentrating the clear liquid obtained in the step E, cooling, carrying out centrifugation to obtain a sodium thiocyanate wet product, and drying the wet product, thereby obtaining a sodium thiocyanate product, wherein the centrifugation mother liquid is fed back to the step E for treatment. The production process disclosed by the invention is simple to operate, easy to control and stable in production process, the obtained sodium thiocyanate is high in quality and high in yield, and byproducts ammonia water and mirabilite are generated.

Description

technical field [0001] The invention belongs to the technical field of compound production, and specifically relates to a production process of high-quality sodium thiocyanate. The production process of the invention is simple to operate and easy to control, and the production process is stable and stable. The obtained sodium thiocyanate has high quality and high yield , At the same time by-product ammonia and Glauber's salt. Background technique [0002] Sodium thiocyanate is an important chemical raw material, used as chemical analysis reagent, polyacrylonitrile fiber spinning solvent, color film film rinse agent, certain plant defoliants, etc. At present, the production process of sodium thiocyanate: Yuan Zhongpei, new production process of sodium thiocyanate liquid, sodium cyanide and sulfur synthesis method reported in scientific research and technology development, raw material sodium cyanide is a highly toxic chemical, the production process has certain danger, and b...

AI Technical Summary

Problems solved by technology

Patent application number 201310608887.8, application number 201510409511.3, application number 201510411352.0 and other reported sodium thiocyanate extraction processes all extract sodium thiocyanate from the coking desulfurization waste liquid of the sodium-alkali method, and use hydrogen for the removal of sulfate radical impurities. Calcium oxide precipitation method, because calcium sulfate still has a certain solubility in water, so the sulfate group cannot be completely removed, and there is still 0.1% sodium sulfate residue in the obtained sodium thiocyanate, and the purity is not enough

[0003] Patent application number 201210388459.4, application number 201410203103.8, application number 201410221396.2, application number 201310436840.8, application number 201410220595.1, application number 200910104293.7, and application number 201310021504.7 are all thiocyanate extraction processes reported from mixed liquid sodium or alkali extraction Sodium thiocyanate is produced by organic solvent recrystallization or extraction process. The disadvantages are that the organic solvent is volatile, the loss is large, the cost is high, and the organic solvent is flammable and explosive, which is relatively dangerous.

[0004] Patent application number 90106150.6 uses ammonia and carbon disulfide to first synthesize ammonium thiocyanate, and then carry out metathesis reaction with sodium hydroxide to produce sodium thiocyanate. The existing problem is that the synthesis process of ammonium thiocyanate is relatively complicated, involving high temperature and high pressure, and the raw materials The cost is also relatively high

[0005] Patent application number 201110166190.0 is to first convert the desulfurization waste liquid into sodium salt through the ammonia-alkali method, and then use calcium hydroxide precipitation to remove the sulfate radical. The existing problem is that the sulfate radical is not completely removed, and the sodium thiocyanate product is not pure.

[0006] Patent application number 201110164965.0, application number 201110235833.2, application number 201110080287.X, etc. are reported to convert the sodium thiocyanate in the desulfurization waste liquid into cuprous thiocyanate first, and then further into sodium thiocyanate for purification. The product has low purity, poor color, and may contain heavy metals

[0007] Patent application number 201010231900.9, application number 201110180361.5, application number 201110357301.6 and other patents all adopt the method of fractional crystallization to purify sodium thiocyanate. The problem is that the separation is not complete and the quality of sodium thiocyanate is poor.

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