Method for preparing high-purity zinc by electrolysis

Abstract

The invention provides a method for preparing high-purity zinc by electrolysis. The method comprises the following steps: leaching a zinc-containing material using an ammonium chloride solution to obtain a zinc-ammonia complex solution; performing impurity removal on the zinc-ammonia complex solution through constant-voltage electrolysis to remove most of impurity ions which are more electropositive than zinc from the solution; after impurity removal through constant-voltage electrolysis, allowing the zinc-ammonia complex solution to flow through a zinc particle vibration purifier to replace the residual impurity metal ions in the solution and thus to achieve the effect of deep purification of the solution; adding carbon-ammonium into the zinc-ammonia complex solution after deep purification to perform ammonia treatment and remove a part of calcium and magnesium ions from the solution; and performing electrolysis on the ammonia-treated solution to obtain high-purity metal zinc. Compared with the prior art of zinc preparation through electrolysis of a zinc-ammonia complex compound, the method provided by the invention adopts carbon-ammonium to replace liquid ammonia, so as to reduce the consumption cost of ammonia and avoid the enrichment of calcium and magnesium in the solution; and performs deep purification by impurity removal through constant-voltage electrolysis and treatment of the solution with the zinc particle vibration purifier after electrolysis impurity removal, so as to completely eliminate the use of zinc powder in the purification link, greatly reduce the purification cost and produce the purified solution which is higher in quality than purification with zinc powder. Therefore, the method stably produces No.0 metal zinc.

Description

technical field [0001] The invention relates to the field of hydrometallurgy, in particular to a method for electrolytically preparing high-purity zinc. Background technique [0002] Zinc secondary resources and zinc oxide ores with high iron content, high fluorine and chlorine content or high calcium and high magnesium content are very rich, but because they contain high iron, high fluorine and chlorine or high calcium and high magnesium, conventional acid process cannot be used The processing and production of electric zinc has caused a large amount of zinc resources not to be used as they should. Many domestic research institutes and enterprises have done a lot of research and development work in this respect, such as Chinese patents CN1034231C, CN101289706A and CN1125883C disclose different methods of producing zinc by electrolysis of complexes, which better solve the problem of elements such as iron and chlorine. Detrimental impact on production, however many deficienc...

AI Technical Summary

Problems solved by technology

There are two unfavorable factors such as using liquid ammonia: 1), liquid ammonia is an industrial commodity, and its price is high, making the production cost on the high side; 2), liquid ammonia is a volatile toxic substance, which is extremely dangerous during transportation and use. To use pressure-resistant containers and pipes, the operation is complicated and unsafe

There are also two unfavorable factors in the use of ammonia water: 1), ammonia water is a low-content liquid ammonia liquid, which is inconvenient to transport, and the transportation cost is higher; 2), adding ammonia water will inevitably bring in a large amount of water in the process of preparing zinc, resulting in system volume expand

[0004] 2. None of the above patent methods consider how to eliminate the enrichment of calcium and magnesium, and if the concentration of calcium and magnesium ions in the electrolyte is higher than 20g / L, it will hinder the electrodeposition of zinc ions, and at the same time, it is easy to form crystals to block the pipeline valve

[0005] 3. The above-mentioned patented methods all rely on zinc powder to purify and remove impurities, resulting in excessive zinc powder consumption and high cost. At the same time, the removal effect of lead, cadmium and copper is not ideal, which affects product quality and cannot produce high-purity zinc ingots.

[0006] 4. The whole process of CN101289706A and CN1125883C adopts the ammonium-ammonia-water system, the ammonia volatilization is serious in the whole process, the ammonia smell is too strong, and the environmental conditions are very bad

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