Study on Acid-Alkali Combined Leaching Process of Low-Grade Tungsten-Tin Mixed Ore AITranslate

Basic Information:

DOI：

Chinese Library Classification Number:TF841.1[冶金工程—有色金属冶金]

Citation Information:

To address the technical challenges in the comprehensive development and utilization of Nanling tungsten-tin polymetallic resources,an acid-alkali combined decomposition process was employed to treat low-grade tungsten-tin mixed ore,achieving efficient leaching of tungsten and resourceful enrichment of tin.The influences of various parameters on the decomposition of tungsten minerals and the reaction behavior of cassiterite during the leaching process were investigated.The results demonstrate that the decomposition of the scheelite component in the minerals requires a high concentration of HCl to provide sufficient driving force,while excessively high H_3PO_4 concentration is detrimental to it.The efficient decomposition of wolframite component is achieved using the conventional alkali autoclaving method,with the associated Sn being enriched in the alkali decomposition slag.In the acid leaching process,a mixed acid of 5 mol/L HCl+75 g/L H₃PO₄ is used as the leachant.Under the process conditions of a liquid-to-solid ratio of 2.5∶1,a reaction temperature of 80℃,and a reaction time of 2 h,the W leaching rate is 77.89%and the W content in the slag is 4.58%.In the alkali leaching process,controlling the conditions of a NaOH concentration at 300 g/L,a liquid-to-solid ratio of 1.25∶1,a reaction temperature of 130℃,and a reaction time of 1.5 h,the W leaching rate could reach 99.79%with the W content in the slag only of 0.06%.The complex occurrence state of Sn in the mixed ore causes its slight loss in both acid and alkali leaching systems.The Sn content in the alkali decomposition slag is enriched to 11.21%,which can be used as a medium-grade tin concentrate for resource utilization.