Method for removing chlorine from zinc solution by adopting cadmium removed and surface naturally-oxidized copper slag

Abstract

The invention relates to a method for removing a chlorine from zinc solution by adopting cadmium removed and surface naturally-oxidized copper slag, and belongs to the field of zinc wet metallurgy. The method concretely comprises the following steps: 1, leaching cadmium from fresh copper and cadmium slag of the zinc solution in sulfuric acid to obtain cadmium removed copper slag with the Cu content of 15-70% and the Cd content of 0.2-1%; 2, piling up the cadmium removed copper slag until the surface is naturally oxidized and the natural oxidation degree is 5-35%; 3, adjusting the initial sulfuric acid concentration by using a chlorine-containing zinc solution, adding 5-50 kg / m<3> of the oxidized copper slag, and stirring the solution and the oxidized copper slag, wherein a ratio of NCu / NCl is 1.4-2.0, the chlorine removal temperature is controlled to be 30-80 DEG C, and the chlorine removal duration is 0.5-1 h; and 4, carrying out filtration and removal after the reaction ends in order to obtain a chlorine removed zinc solution and chlorine removed slag. The method adopting a prior cadmium removal technology reduces the impurity content of the copper slag, and improves the copper grade of the copper slag; the cadmium removed and surface naturally-oxidized copper slag is adopted to substitute fresh copper slag, so a copper sulfate or oxidized leached copper slag process for preparing a copper sulfate solution is avoided; and the method has the advantages of effective simplification of the process, production cost reduction, and increase of enterprises' economic benefits.

Description

technical field [0001] The invention belongs to the field of zinc hydrometallurgy, and in particular relates to a method for removing chlorine from zinc solution by adopting surface natural oxidation copper slag after removing cadmium. Background technique [0002] The zinc leaching solution contains chloride ions up to 1g / L after accumulation in the wet system, which causes equipment corrosion and anode plate corrosion during the electrolysis process, and causes corrosion products to deposit on the cathode plate, affecting the yield of zinc plates, increasing cathode power consumption, and zinc flakes Difficult to peel off. Especially for the application of zinc electrolysis large plate, the content of chloride ion is required to be less than 300mg / L. At present, the common copper slag dechlorination method in industry is to use the disproportionation reaction of copper. The specific chemical reaction is as follows: [0003] Cu+Cu 2+ +2Cl - =Cu 2 Cl 2 ↓ [0004] In i...

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Problems solved by technology

[0002] The zinc leaching solution contains chloride ions up to 1g / L after accumulation in the wet system, which causes equipment corrosion and anode plate corrosion during the electrolysis process, and causes corrosion products to deposit on the cathode plate, affecting the yield of zinc plates, increasing cathode power consumption, and zinc flakes Difficulty peeling off

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