A kind of method utilizing dithianon production mother liquor to prepare sodium sulfate

Abstract

The invention relates to a method for preparing sodium sulfate by using dithianon to produce mother liquor, which comprises the following steps: 1)under 10-40 DEG C, dropping sulfuric acid to the mother liquor produced by dithianon; wherein the mass ratio of mother liquor to sulfuric acid is 8-16: 1; and 2)performing pumping filtration on a solution after the reaction is completed, dissolving the obtained solid by water, decolouring the active carbon, recrystallizing to obtain sodium sulfate; or adding a solvent with volume ratio of 1: 0.5-2 and then performing pumping filtration, recrystallizing the solid by water to obtain sodium sulfate, and recrystallizing the mother liquor for indiscriminate application. The method has the advantages that the technology is simple, the cost is low, discharge of waste liquid is reduced, no waste residue is generated, environment pressure is mitigated, production cost is reduced, and the method has good application prospect.

Description

Technical field [0001] The invention belongs to the field of pesticide production and recovery, and particularly relates to a method for preparing sodium sulfate using dithianon production mother liquor. Background technique [0002] Dithianon various preparations mainly inhibit a series of fungal enzymes by reacting with sulfur-containing groups and interfering with cell respiration, and finally lead to the death of pathogens; it has good protective activity on its own, and also has high medicinal activity. Therefore, the drug is widely used in fruit tree diseases. The pesticide product is in huge demand worldwide and the market is stable. [0003] Dithio agricultural products have a large production capacity and produce a large amount of waste water every day. The main components of its cyclization mother liquor include: dimethyl sulfoxide, sodium acetate, naphthoquinone and some intermediates. It contains about 25-40% of DMSO; about 10-20% of sodium acetate; about 10% of other...

AI Technical Summary

Problems solved by technology

Wastewater is alkaline, with high chroma and complex composition

Among them, sodium acetate has a high solubility in the solution and cannot be recovered. Dimethyl sulfoxide is a solvent in the synthesis and consumes a lot. At present, the method of taking the mother liquor is to dry the waste liquid through a rake dryer, and distill and recover dimethyl sulfoxide. , the method consumes a lot of energy, the recovery rate of dimethyl sulfoxide is not high, and a large amount of sodium acetate in the mother liquor cannot be recycled, resulting in a large amount of high chroma, complex components, and difficult to handle waste residue, resulting in a waste of resources. Increased production costs