Method for producing zinc sheets and recycling ammonium chloride from indium contain wastewater

Abstract

The invention discloses a method for producing zinc sheets and recycling ammonium chloride from indium contain wastewater. The method includes the following steps that the indium contain wastewater with 300-500 g / L of ZnCl2 is mixed with ammonium chloride, a mixed solution is formed and electrolyzed, anode zinc sheets and a zinc chloride-ammonium chloride-high hydrochloric acid mixed solution are produced, and the anode zinc sheets serve as products to be sold; the zinc chloride-ammonium chloride-high hydrochloric acid mixed solution is pre-neutralized through basic zinc carbonate and ammonium bicarbonate, and a zinc chloride-ammonium chloride-low hydrochloric acid mixed solution is produced; part of the zinc chloride-ammonium chloride-low hydrochloric acid mixed solution returns to an electrolytic cell to be electrolyzed, and 50% of the residual solution is subjected to neutralizing and zinc precipitating through ammonium bicarbonate; basic zinc carbonate and an ammonium chloride solution are produced after neutralizing and zinc precipitating, and the basic zinc carbonate returns to be pre-neutralized; and the ammonium chloride solution is evaporated and condensed, an ammonium chloride solid is obtained, part of the ammonium chloride solid returns to be electrolyzed, and the residual ammonium chloride serves as products to be sold. According to the method, the technical process is short, the zinc metal recycling rate is high, product additional value is high, and the production process is clean and environment-friendly.

Description

technical field [0001] The invention relates to a method for comprehensive recovery of nonferrous metals, in particular to a method for producing zinc flakes and recovering ammonium chloride from liquid after indium replacement. Background technique [0002] At present, in the production process of indium ingot products, 90% of indium ingots are completed by the conventional process of extracting indium solution with P204 organic solvent. This conventional process mainly has four processes, namely P204 organic solvent extraction, hydrochloric acid stripping, Zinc ingot replacement, crude indium electrolysis. [0003] In the P204 organic solvent extraction process, since the affinity of the organic solvent to indium ions is greater than that of sulfuric acid-indium sulfate solution to indium ions, the indium metal ions in the solution will be complexed by the organic solvent and enter the organic solvent, correspondingly , the hydrogen ions in the organic solvent are transfe...

AI Technical Summary

Problems solved by technology

The process of this method is simple, the equipment investment is low, and the land occupation is small; there are five disadvantages, one is that the end point of evaporation and concentration is difficult to control, and the product qualification rate is low; the other is that the product market demand is small and the product is difficult to sell; the third is the added value Low, there is almost no economic benefit in recovering the liquid after indium replacement. Fourth, zinc chloride products are corrosive and require protective treatment in product packaging, storage, transportation, and use. Fifth, zinc chloride is a low-boiling substance that evaporates When concentrated, a small amount of gas will be produced, polluting the production site, and the site environment is poor

The advantage of this method is that the process is simple, and the process is easy to control, and the product is zinc flakes, which is of high value; the disadvantage is that the investment in equipment is large, and the chlorine gas produced during the electrolysis process is a toxic gas, the site conditions are poor, the environmental pollution is large, and it needs to be treated. After electrolysis, the solution is evaporated and concentrated according to the adaptation, and the production cost is high

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