Method for recovering sodium chloride from glyphosate mother liquid

Abstract

The invention discloses a method for recovering sodium chloride from glyphosate mother liquid. The method is characterized by comprising the following steps: dehydrating the glyphosate mother liquid for at least one time to obtain dehydrated liquid; after dehydrating the dehydrated liquid to critical concentration, adding a quenching agent to obtain a mixture, wherein a waxing phenomenon occurs inthe dehydrated liquid at the critical concentration; separating the mixture to obtain isolate, wherein the isolate comprises a sodium chloride crude product; performing at least one-stage counter-current soluble washing on the separated sodium chloride crude product to obtain sodium chloride crystalline liquid; separating the sodium chloride crystalline liquid to obtain a sodium chloride transition product; and performing at least one-stage counter-current drip washing on the sodium chloride transition product to obtain refined sodium chloride. The treatment problem of sodium chloride solid waste is effectively solved, effective components in the mother liquid is completed recycled, operation is simple, the needed low-grade heat source is cheap and easily available, and the effective components in the glyphosate mother liquid can be recovered greenly, efficiently and economically.

Description

technical field [0001] The invention relates to a method for recovering sodium chloride from glyphosate mother liquor. Background technique [0002] At present, China is a large agricultural country with a population of more than 1.4 billion. Self-sufficiency in food is the foundation of national development and stability. Glyphosate (N-(phosphonomethyl)glycine) is a highly efficient, low-toxic, broad-spectrum, It is a safe herbicide with good systemic and conductive properties. It is very effective in the control of perennial deep-rooted weeds. It is widely used in agriculture, forestry, animal husbandry, and horticulture. It is currently the world's largest pesticide in sales Variety. In recent years, due to glyphosate-resistant transgenic crops and the large-scale promotion of biofuel crops due to energy shortages, new opportunities have been provided for the production and application of glyphosate, and the importance of glyphosate to agriculture has become increasingly...

AI Technical Summary

Problems solved by technology

[0007] For example, membrane glyphosate mother liquor treatment technology has been industrialized in some domestic glyphosate enterprises, but the membrane technology only realizes the relative separation of different components in the mother liquor, and only redistributes the organic matter in the mother liquor, and has not been obtained. Effective recycling, transformation or disappearance

Moreover, the main organic impurities in the mother liquor are still concentrated for the preparation of 30% water preparation, and will still be transferred to the ecological environment, causing new pollution

At the same time, there is still no effective treatment method for other organic components remaining in the mother liquor, resulting in a great waste of resources. If it is transferred to hazardous solid waste, the cost will be high, and it is difficult for production enterprises to accept

The phosphorus-containing, nitrogen-containing, and macromolecular organic substances still contained in the industrial salt treated by the membrane method will shorten the service life of the expensive membrane and cannot be used in the ion-exchange membrane caustic soda industry.

Due to the limitations of membrane glyphosate mother liquor treatment technology and the high investment and operation costs, its application prospects will be greatly limited

[0008] For example, the Chinese invention patent application with the application number 200910114938.5 and titled "A Method for Recovering Raw Glyphosate Powder from Glyphosate Mother Liquor", the patented method removes salt under strong acid conditions, although it can remove sodium chloride and other inorganic Salt outside the range of salt solubility is removed, but a large amount of inorganic salts within the range of solubility still exist in the mother liquor; and although the method can extract glyphosate powder, only 20-30% of glyphosate powder can be extracted due to the existence of inorganic salts. Glyphosate, and the quality of raw powder is obviously reduced; what's more, because of the use of excessive concentrated hydrochloric acid to convert and extract sodium chloride under the condition of so much mother liquor, the problem of equipment corrosion under the hydrochloric acid system is difficult to solve, and the investment is too high As a result, the manufacturer cannot accept it and can only stay at the stage where it cannot be implemented

[0009] For example, the invention patent application with the application number 201010186170.5 and titled “A Method for Recovering Raw Glyphosate Powder from Glyphosate Mother Liquor” has complex forms of glyphosate products, raw materials and by-products in the mother liquor, and only through Add crystal water without providing energy, and the glyphosate molecules in the mother liquor cannot be crystallized in large quantities; at the same time, the mother liquor contains salt, and a small amount of glyphosate precipitated will contain a large amount of salt, which will affect the quality of glyphosate

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