Method for recycling ammonium chloride in APT (ammonium paratungstate) production process

Abstract

A method for recycling ammonium chloride in an APT (ammonium paratungstate) production process comprises steps of ammonia activation, stripping, hydrochloric acid spray and the like, wherein ammonia-nitrogen wastewater is adsorbed and pre-activated with pretreated activated carbon before ammonia activation, three-stage stripping is adopted, a small amount of nitrogen is introduced in the process,so that concentration of a sodium hydroxide solution can be reduced, ammonium chloride with higher concentration can be obtained, the requirement for recycling and preparing a desorption liquid is met, and further, NH3-N concentration of deaminated wastewater and ammonia content of discharged waste gas meet Integrated wastewater discharge standard (GB8978-1996) and Emission standards for odor pollutants (GB14554-93).

Description

technical field

[0001] The invention relates to a method for recycling ammonium chloride, in particular to a method for recycling ammonium chloride in the production process of APT. Background technique

[0002] Ammonium paratungstate (APT) is produced by tungsten smelting ion exchange method, the tungsten-containing raw material is converted into sodium tungstate solution by pressure alkaline leaching method, and suitable alkalinity and tungsten degree are prepared, ion exchange column exchange is carried out, and tungsten is absorbed by ion exchange resin Impurities are removed, and then desorbed by a desorbent (ammonia-ammonium chloride solution). The tungsten is converted into ammonium tungstate solution. After the desorption liquid is removed, it is the product liquid. APT products.

[0003] Therefore, the ammonia nitrogen wastewater produced in the smelting process is mainly produced in the ion exchange and APT crystallization process in the APT production process. If...

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