Separation of a Tungsten-tin Rough Concentrate by Flotation-hydrometallurgy Combined Process

Objective To achieve the effective separation of useful minerals from gangue, by taking advantage of the difference in specific gravity between cassiterite and gangue, tungsten was also enriched in the crude concentrate of tin through gravity separation. MethodThe tungsten-tin rough concentrate produced by the shaking table of a concentrator in Inner Mongolia is taken as the research object, and a flotation-hydrometallurgy combined separation process is used to separate the tungsten-tin rough concentrate of a concentrator. The scheelite in the tungsten-tin rough concentrate is preferentially enriched by flotation method, and then the flotation tailings are treated by hydrometallurgy to recover the wolframite in the tungsten-tin rough concentrate. ResultThe flotation results show that the scheelite concentrate with WO₃ grade of 66.43% and recovery of 67.29% is obtained by using the closed-circuit process of 'one roughing, two scavenging and three cleaning'. Tungsten hydrometallurgical experiments were carried out on the flotation tailings. The leaching rate of WO₃ reached 94.77%, the Sn grade of the leaching residue was 46.47%, and the recovery rate was 95.60%, which could be sold as the tin concentrate. Conclusion The separation process not only successfully separated scheelite and cassiterite, but also effectively recovered wolframite, and realized the efficient comprehensive utilization of tungsten-tin rough concentrate, which provided an important technical reference for the separation and recovery of similar minerals.