Process for concentrating pesticide mother liquor by film method

Abstract

The invention relates to a method for concentrating the membrane pesticide mother liquid, which comprises following steps: at the temperature of 0-45Deg. C, pre-treating the low-density glyphosate mother liquid whose density is lower than 5%, to reach the demand that feeding water into the ultra-filter, to enter into the first-stage ultra-filtration film system; said glyphosate mother liquid is separated by ultra-filtration film into two flows, while the dense flow is fed back to the raw liquid box, and the light flow enters into the second-stage containing filtration film system; and the glyphosate mother liquid that entering into the second-stage containing film system is divided into two flows, while the dense one is fed back to the front inlet to be fed into liquid storage groove until the concentration reaches 7-12%, and the light solution enters into the third-stage anti-penetrate film system; then the glyphosate mother liquid that enters into the third-stage anti-penetrate film system is divided into two flows, while the dense flow is fed back to the inlet of second-stage containing filtration film system. The invention has the advantages that; 1, it uses film seperatpr without electricity; 2, it has lower working temperature, to solve the problem that the glyphosate is easily to be decomposed in high temperature; 3 it can avoid pollution, without overflowing ammonia gas.

Description

Technical field [0001] The invention relates to a concentration process, mainly a concentration process of a glyphosate mother liquor by a membrane method. Background technique [0002] Glyphosate is a widely used sterile post-emergence herbicide. Because of its excellent herbicidal performance, its application range has been continuously expanded, and its output has grown rapidly, and it has become an important species of herbicides worldwide attention. One of its synthetic methods is to synthesize iminodiacetic acid (IDA) as an intermediate. This method has the characteristics of short steps, high yield, and less three wastes. However, at the end of glyphosate production, a large amount of mother liquor after taking out the crystallization is low in concentration, containing only 3% of active ingredients, and the recycling rate is low. The traditional processing technology mainly includes: [0003] 1. Pour ammonia into the glyphosate mother liquor, adjust the PH value to 7-10, ...

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Problems solved by technology

[0005] 3. Evaporating and concentrating the mother liquor into 10% water agent for sale, low economic benefit

[0006] The first method requires additional addition of ammonia water, and the high energy consumption of vacuum distillation is not conducive to reducing product costs; the second method requires additional addition of ammonium bicarbonate, and requires press filtration, which consumes a lot of labor; the third method, evaporation The concentration process will cause three major problems: 1. The energy consumption of evaporation is high, and the cost is relatively high; 2. The steam generated by evaporation contains part of NH3, which will pollute the environment; 3. Glyphosate is easy to decompose at high temperature, so that drop in recovery

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