New method for removing fluorine in zinc solution through sodium aluminate

Abstract

The invention relates to a new method for removing fluorine in a zinc solution through sodium aluminate, and belongs to the field of zinc hydrometallurgy. The new method comprises the specific operation steps that 1, industrial grade sodium aluminate powder and water are mixed to prepare a mixed solution with the concentration of 5%-50%, the solution is sufficiently stirred for use, and the mixed solution has no obvious agglomeration phenomenon after being sufficiently mixed; 2, the sodium aluminate solution is gradually added into the fluorine-containing zinc solution (with the fluorine content being 100-600 mg / L), sufficient stirring is carried out for removing fluorine, the fluorine removing temperature is controlled to be 15-50 DEG C, and the fluorine removing time is controlled to be 0.5-2 h; and 3, after the reaction in the step 2 is finished, a zinc solution with fluorine removed and fluorine-removed slag are obtained through solid-liquid separation. According to the method, the industrial grade sodium aluminate powder is adopted for the first time in the technology of removing fluorine in the zinc solution, the fluorine-removed slag amount is reduced, the filter performance of the solution with fluorine removed is improved, the industrial grade sodium aluminate powder is easy to obtain, the purification temperature is low, purification time is short, the fluorine removing technology is simplified, and economic benefits of enterprises are improved.

Description

technical field [0001] The invention belongs to the field of zinc hydrometallurgy, and in particular relates to a new method for removing fluorine in zinc solution by using sodium aluminate. Background technique [0002] In the process of zinc hydrometallurgy, when the fluorine content accumulates to a certain value, the consumption of electrolytic anodes and cathodes will be increased, and the working environment will be deteriorated. Especially in the electrowinning process of zinc sulfate, fluoride ions can destroy the aluminum oxide film on the surface of the cathode aluminum plate, so that the precipitated zinc and the fresh surface of the aluminum plate form zinc-aluminum alloy, which makes it difficult to peel off the zinc skin, increases the consumption of the cathode aluminum plate, and reduces the quality. The electrolysis process cannot proceed properly. Therefore, the fluorine content in the zinc sulfate electrolyte is required to be less than 50 mg / L at home an...

AI Technical Summary

Problems solved by technology

However, zinc smelters generally use plate-frame or box-type filter presses to filter calcium fluoride precipitates. The filtering effect is poor, and the wet system solution is acidic, which is not conducive to the formation and filtration of calcium fluoride precipitates.

[0005] The defluorination test of 201# and 291# resin has been carried out in China, but the exchange capacity is weak, the regeneration cost is high, and there is no industrialized example