Method for removing chlorine from zinc sulfate solution

Abstract

A method to remove chlorine from zinc sulfate solution pertains to nonferrous metallurgy. The chlorine in the zinc sulfate solution is removed through elementary copper in copper slug and Cu2+ generated from oxidation of copper slug react with chloride ion to get insoluble CuCl precipitation. The invention makes a further use of copper slug generated from wet zinc melting method, first partial elementary copper in the copper slug is oxidized and then Cu2+ ion is obtained without adding copper sulfate, realizing the effect that elementary copper and Cu2+ ion are both supplied by the slug to involve in chlorine removal reaction. When in the chlorine removal process, no copper sulfate is added and the copper slug is made a full use, therefore, production cost is reduced, operation process is simplified, no waste slug, waste gas and waste water are added and no pollution is done to the environment and as materials involved in the invention are ordinary materials and are not needed and consumed in a large amount, the invention has remarkable economic effect.

Description

technical field [0001] The invention relates to a method for removing chlorine in zinc sulfate solution, belonging to the field of nonferrous metal smelting. Background technique [0002] In the process of zinc hydrometallurgy, chlorine is a harmful impurity element, mainly derived from chlorides in zinc concentrate and zinc fume. The concentration of chlorine in the electrolytic circulating solution is high (Cl - >0.3g / L), the corrosion speed of electrolytic cathode and anode plates is greatly accelerated, which increases energy consumption and reduces the quality of electrolytic zinc. Therefore, before the zinc sulfate solution is sent to electrolysis, most of the chlorine in the solution must be removed. At present, some factories usually use the pre-fire method (such as multi-hearth furnace) roasting to remove the chlorine in the zinc fume, so that most of the chlorine does not enter the wet system, and when the chlorine in the zinc sulfate solution in the wet syste...

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Problems solved by technology

[0007] The specific method is: add copper sulfate (copper ion) and copper slag (containing elemental copper) in the zinc sulfate solution, the source of copper sulfate is mainly purchased or the copper-containing slag is acidified roasting, water immersion to obtain copper sulfate, the former ( Refers to the purchase of copper sulfate) requires a relatively large increase in production costs, the latter (referring to the acidification roasting of copper-containing slag, water immersion to obtain copper sulfate) in addition to relatively high production costs, the operation is also relatively complicated

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