Method for preparing sodium thioglycolate critical saturated aqueous solution from thionocarbamate tail liquid

Abstract

The invention relates to a method for preparing a sodium thioglycolate critical saturated aqueous solution from thionocarbamate tail liquid. The method comprises the steps of: firstly, acidizing the tail liquid of raw thionocarbamate with inorganic acid to obtain acidizing liquid with pH ranging from 0.5 to 2; standing the acidizing fluid for separating into an upper organic layer and a lower acidizing layer; adding an organic solvent into the acidizing layer for extraction; adding a sodium hydroxide solution into the extracted liquid for reaction, and recovering the organic solvent to obtainthe sodium thioglycolate critical saturated aqueous solution. According to the method, the thionocarbamate tail liquid is used for preparing the sodium thioglycolate critical saturated aqueous solution, the saturated solution can be directly used, and the characteristics that a sodium thioglycolate solid product is large in production energy consumption, prone to moisture and unstable are avoided;the prepared sodium thioglycolate critical saturated aqueous solution is high in purity, does not contain other impurities, and particularly does not contain thionocarbamate.

Description

technical field [0001] The invention belongs to the technical field of chemical environmental protection, and in particular relates to a method for preparing sodium thioglycolate critical saturated liquid by using thiourethane tail liquid. Background technique [0002] Sodium thioglycolate, also known as sodium thioglycolate. It is an organometallic salt. The CAS number is 367-51-1. In the flotation of copper-molybdenum ore, because there are two polar groups in the molecular structure of sodium thioglycolate, the sulfhydryl group chemically reacts with these two minerals and adsorbs on the surface of the mineral, while the carboxyl group exists in such a small molecule that it is impossible to show Collecting performance, but it can show hydrophilicity to form a water film, replace sodium cyanide and sodium hydrosulfide as an inhibitor of copper minerals and pyrite, and has the characteristics of less dosage, non-toxic, non-polluting, high-efficiency, etc. , can improve ...

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Problems solved by technology

[0007] The above-mentioned patents all reuse thiourethane waste liquid, and obtain a new type of alkyl sulfide ethyl hydroxamic acid through hydroximation to obtain a new collector. Halogenation and esterification reactions, the final waste liquid is more difficult to handle; 99.99% thioglycolic acid product is obtained through tail liquid purification, although the final recovered product is extremely pure, but a large amount of organic solvent waste is also produced in the whole process liquid, and this method is more suitable for use in the laboratory; two times of alkalization are carried out in the waste liquid after ether extraction, and quicklime is used for the first alkalization in this patent, which will produce a large amount of calcium thioglycolate, which will affect the sodium thioglycolate. In addition, the use of ether will not only cause great harm to the operator, but also greatly reduce the recovery rate and produce a large amount of intermediate waste liquid. The sodium thioglycolate recovered in the actual use of this method has low efficiency and contains a large amount of impurities.

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