Method of reducing calcium content in high calcium sulfate content feed liquid

Abstract

The invention provides a method of reducing calcium content in a high calcium sulfate content feed liquid and belongs to the technical field of hydrometallurgy. The method of reducing calcium contentin the high calcium sulfate content feed liquid comprises the following steps: mixing the high calcium sulfate content feed liquid with calcium sulfate crystal seeds; and carrying out sedimentation treatment, ageing and solid-liquid separation, successively, wherein the content of calcium sulfate in the high calcium sulfate content feed liquid is 2.30-2.56 g / L, and the pH value is 4.0-4.5; and thegrain sizes of the calcium sulfate crystal seeds are 11-18 [mu]m. The calcium sulfate crystal seeds with special grain sizes are adopted to induce calcium sedimentation, so that the content of calcium sulfate in the feed liquid can be reduced effectively, a condition that calcium sulfate precipitates in an extraction tank are cleaned frequently in a follow-up extraction and calcium removal step is avoided, the manpower and material resources are saved, and the production efficiency is improved. In addition, the method provided by the invention is simple in step and high in operability, and facilitates scale production.

Description

technical field [0001] The invention relates to the technical field of hydrometallurgy, in particular to a method for reducing calcium content in feed liquid with high calcium sulfate content. Background technique [0002] In the process of metal hydrometallurgy, in order to ensure the smooth progress of the smelting process, it is necessary to remove impurities from the raw material leaching liquid, and calcium is one of the main impurity elements. The current decalcification methods mainly include fluoride decalcification and extraction decalcification. Fluoride decalcification is to remove copper and iron from the leaching solution, control the system at a specific pH value and temperature, and add fluoride (such as sodium fluoride or ammonium fluoride) to form calcium fluoride precipitation. However, after fluoride decalcification, fluorine will remain in the feed liquid, which will pollute the environment, and the national "Sewage Comprehensive Discharge Standard" allo...

AI Technical Summary

Problems solved by technology

At present, in the production of hydrometallurgy, calcium carbonate is often used to adjust the pH value of the acidic leaching liquid, resulting in too high calcium sulfate content in the system, forming a supersaturated calcium sulfate liquid, and the liquid after copper and iron is removed in the subsequent extraction In the decalcification process, a large amount of calcium sulfate precipitates will be formed in the extraction tank, which will block the pipeline of the extraction tank

Therefore, it is necessary to frequently and regularly clean the calcium sulfate precipitate in the extraction tank, and the production is forced to be interrupted, which wastes manpower and material resources and reduces production efficiency.