Process for extracting ammonium chloride from waste etching liquid and evaporation and concentration system thereof

Abstract

The invention discloses a process for extracting ammonium chloride from a waste etching solution and an evaporation and concentration system thereof, and the process comprises the following steps: S1,filtering an alkaline waste etching solution to remove suspended impurities to obtain a solution a, and adjusting the pH value to 9-10; S2, enabling the solution a to enter a filler extraction towerto be extracted, so as to obtain an organic phase b and raffinate c; S3, adding hydrochloric acid into the raffinate c for tempering to obtain a solution d; S4, in fixed bed adsorption equipment, adsorbing heavy metal ions in the solution d by adopting L-glutamic acid chelating resin to obtain an ammonium chloride solution e and a desorption solution f; S5, evaporating and concentrating the ammonium chloride solution e to obtain an ammonium chloride concentrated solution g; and S6, cooling and crystallizing the ammonium chloride concentrated solution g. The evaporation and concentration systemcomprises a liquid feeding device, a negative pressure evaporation device, a condensation device and a condensate water collection device which are connected through pipelines. The method can be applied to waste liquid treatment plants and has the advantage of extracting the purity of ammonium chloride.

Description

technical field [0001] The invention relates to the technical field of ammonium chloride recovery, more specifically, it relates to a process for extracting ammonium chloride from waste etching solution and an evaporation and concentration system thereof. Background technique [0002] Printed circuit board (PCB) is an important part of electronic products. In recent years, with the rapid development of the electronic industry, the demand for PCB is increasing, and the PCB industry has achieved rapid development. With the continuous development of the PCB industry, the environmental protection issues of this industry are becoming more and more important. One of the main pollution is the large amount of copper-containing etching waste produced in the etching process. This waste liquid mainly comes from the PCB etching process. The etching liquid can corrode the excess copper foil on the circuit board, so that the concentration of copper ions in the etching liquid increases con...

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Problems solved by technology

[0004] This method has the following defects: due to the removal of ammonium ion (NH 4+ ), chloride ion (CL - ), and unextracted copper ions (Cu 2+ ) and other heavy metal impurities, although a certain amount of ammonium chloride product can be obtained through simple concentration treatment, but the purity of the ammonium chloride product is low, and the selling value is relatively low

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