Method for preparing ammonia water and calcium chloride solution through decomposition recovery of ammonium chloride waste liquor

Abstract

The invention discloses a method for preparing ammonia water and calcium chloride solution through the decomposition recovery of ammonium chloride waste liquor. The method comprises the following steps: the waste liquor is pretreated, and ammonium chloride and calcium oxide or calcium hydroxide powder is added into the pretreated ammonium chloride waste liquor; ammonia is distilled from the treated ammonium chloride waste liquor and is transferred into an ammonia absorption tower after being condensed, and a reaction liquid flows out from the bottom of a distillation tower; ammonia is absorbed from the condensed ammonia in the absorption tower by using desalted water, and the tail gas is exhausted after residual ammonia is washed by a tail gas washing tower; reaction liquid out of the bottom of the distillation tower is subjected to flash vaporization for recycling the energy and then is transferred into a clarifying barrel, and the clarified calcium chloride supernatant is used as the target product. According to the invention, the method is particularly suitable for the transformation of ammonium chloride wastewater treatment technology of enterprises in the existing rare earth industry, potassium carbonate industry and baking soda industry, and is simple in process; the ammonia is recycled by using desalted water through multi-stage absorption, and the recovery rate is up to 99%; the high-concentration calcium chloride solution can be used for producing calcium chloride products and the products can be recycled so as to have better economic benefits.

Description

technical field [0001] The invention relates to a treatment method for ammonium chloride waste liquid, in particular to a method for decomposing and recovering ammonium chloride waste liquid to prepare ammonia water and calcium chloride solution. Background technique [0002] The treatment of ammonium chloride wastewater in the rare earth industry, potassium carbonate industry and baking soda industry is a major problem faced by related production enterprises. The recovery effect of biological and physical and chemical methods is not good. With the development of science and technology, some new processes New technology has begun to be applied to the treatment of ammonium chloride wastewater, but in the end it is concentrated to produce ammonium chloride products. At present, there is no treatment method that can bring better economic benefits to enterprises. Ammonium chloride-containing wastewater The processing technology mainly includes the joint application of multi-effe...

AI Technical Summary

Problems solved by technology

[0006] All the above disclosed ammonium chloride wastewater treatment technologies adopt different methods to increase the concentration of ammonium chloride and then evaporate and crystallize the ammonium chloride product, all of which have problems such as high consumption and poor economy.