Method for recycling waste water containing ammonium chloride

Abstract

The invention provides a method for recycling waste water containing ammonium chloride. The method includes the steps of adding ferrous sulfate flocs into waste water containing ammonium chloride after aminolysis, and subjecting the mixture to sedimentation for removing impurities; then adding sodium hydroxide to replace ammonia, stripping ammonia through warming and air compression bubbling, recycling ammonia water, adding acids to surplus waste water containing ammonium chloride to adjust the pH value, and filtering the mixture; and using a filter solution to be partial base water in a chlorination production process of 6-chloro-2,4-dinitro-anilin. According to the method for recycling waste water containing the ammonium chloride, the treatment process is simple and reasonable, the energy is saved, the recycling rate is high, and production environment improvement and environmental protection are facilitated.

Description

technical field [0001] The invention relates to a method for recycling waste water containing ammonium chloride. Background technique [0002] Ammonolysis of p-nitroaniline, 2,4-dinitroaniline and o-cyano-p-nitroaniline produces a large amount of mother liquor containing ammonium chloride, the concentration of which varies from 10 to 20%. The traditional treatment method is to add quicklime to the mother liquor. React ammonium chloride to generate free ammonia. Since ammonia has a high solubility in water, ammonia is recovered by means of pressurized rectification. However, there are four major defects in the traditional ammonia distillation process: first, the equipment investment of the rectification tower under pressure is large, the operation flexibility is small, and the control is difficult; The consumption of steam and cooling water is large; the third is the low ammonia recovery rate. When the ammonia concentration in the tower kettle is below 0.7%, the energy cons...

AI Technical Summary

Problems solved by technology

However, there are four major defects in the traditional ammonia distillation process: first, the equipment investment of the rectification tower under pressure is large, the operation flexibility is small, and the control is difficult; The consumption of steam and cooling water is large; the third is the low ammonia recovery rate. When the ammonia concentration in the tower kettle is below 0.7%, the energy consumption will rise sharply. Therefore, the ammonia concentration in the wastewater is actually controlled at 0.7% to 1.0%, resulting in two Secondary pollution; Fourth, a large amount of calcium sulfate waste residue is produced after lime neutralization and replacement, causing secondary pollution

This type of method for reclaiming ammonium chloride from waste water containing ammonium chloride in the form of solid ammonium chloride will remove a large amount of water in the process of reclaiming ammonium chloride, and the energy consumption is relatively large; and the solid ammonium chloride impurity of reclaiming High content, low use value; if used as a chemical fertilizer, long-term use will cause soil salinization, if used as a chemical raw material, the economic benefit will be low due to its poor purity; moreover, the ammonium chloride solution is highly corrosive, and in Under the conditions of increasing temperature and concentration, the requirements for equipment materials are very high, making it difficult for these methods to obtain good application prospects