Comprehensive recycling utilization method of potassium-containing wastewater generated in synthesis process of dicamba

Abstract

The invention discloses a comprehensive recycling utilization method of potassium-containing wastewater generated in a synthesis process of dicamba. The comprehensive recycling utilization method comprises the following steps: adding acid into potassium-containing wastewater I generated in the synthesis process of the dicamba, and naturally depositing; conveying a water layer obtained by layering into a macroporous adsorption resin bed through a pump; adsorbing and recycling dicamba intermediates, namely 2,5-dichlorophenol and 3,6-dichlorosalicylic acid, in the water layer through the macroporous adsorption resin bed; adding active carbon and stirring and filtering; adding alkali liquid to adjust the pH (Potential of Hydrogen); adding active carbon into potassium-containing wastewater IV; stirring and filtering; conveying the wastewater into a chelating resin bed through the pump; removing high-valent metal cations in the alkaline potassium-containing wastewater IV through ion exchange; conveying the wastewater into a cation exchange resin bed through the pump; carrying out the ion exchange to obtain a potassium hydrogen carbonate solution and an ammonium chloride solution respectively; and drying an obtained potassium hydrogen carbonate wet product to obtain potassium hydrogen carbonate, or calcining the potassium hydrogen carbonate wet product at a high temperature to obtain potassium carbonate.

Description

technical field [0001] The invention belongs to the fields of chemical industry and environmental protection, and relates to chemical synthesis technology, in particular to a method for comprehensive recycling of potassium-containing waste water produced by synthesizing dicamba. Background technique [0002] Dicamba, whose chemical name is 3,6-dichloro-2-methoxybenzoic acid, belongs to the series of benzoic acid herbicides, and is a new herbicide developed by Novartis (now Syngenta) in the 1960s. It has the characteristics of strong selectivity, less dosage, and lower cost. It is mainly used for the control of annual or perennial broad-leaved weeds in fields affected by grasses such as wheat. Dicamba is used for post-emergence spraying, and the drug can be quickly absorbed by the leaves, stems, and roots of the weeds, conduct upward and downward through the phloem and wood, and mostly concentrate in the meristems and parts with strong metabolic activities, hindering the norm...

AI Technical Summary

Problems solved by technology

The selectivity of the phenol hydroxylation reaction in the first step is slightly poor, and various isomers of phenols will be formed, which are difficult to separate, resulting in poor product quality;

[0007] 3. Using 5-bromo-3,6-dichloro-2-methoxybenzyl alcohol as the raw material, undergo debromination and oxidation reactions, or use 5-bromo-3,6-dichloro-benzyl alcohol as the main raw material Bromine, methylation, oxidation reactions to obtain products (US3928432), but the starting materials are not easy to obtain, and the pressure on environmental protection is also very high;

[0009] At present, route 4 is actually used in industry to produce dicamba. The disadvantages of this process route are long reaction time, high energy consumption and low yield.

However, the disadvantages of this treatment method are high energy consumption, severe corrosion of equipment, high operating costs, and inability to effectively remove heavy metal pollutants. The application of treated potassium chloride is limited, and it is not allowed from an environmental protection point of view.

Images