Dissolution Behaviors of Minerals in Tellurium–Bismuth Ore During Oxidic–Acidic Leaching

Abstract

The dissolution behaviors of various minerals in the tellurium-bismuth ore during oxidic-acidic leaching were investigated systematically in this work. The Te-Bi phase in the ore distributes in network shape, triangular shape, tree shape, strip shape, bulk shape, sparse granule, flake shape, crescent, etc., which are closely intercalated with FeS, FeS 2 , and CaCO 3 •(Mg,Fe,Mn) CO 3 . Under suitable conditions, 95.61% Te and 95.77% Bi can be recovered. Within 20 min of the initial leaching, most of dolomite and Te-Bi phase dissolve rapidly. With the extension of leaching time, a large amount of rod-shape CaSO 4 particles form, attach on the surface of the tellurium-bismuth ore particles, and then grow and coarsen. The (Mg,Fe,Al)(Si,Al) O x (OH) y phase dissolves mainly within 60 min. Fe-S phase can be corroded but cannot dissolve completely. SiO 2 cannot dissolve at all. Besides, H 2 SO 4 and Fe 3+ play a significant role on the dissolution of various minerals in the ore. Without Fe 3+ or H 2 SO 4 in immersion liquid, Te and Bi are difficult to be leached into the lixivium from the tellurium-bismuth ore. As H 2 SO 4 concentration and Fe 3+ concentration increase, Te-Bi phase and Fe-Mg-Al-Si-O phase gradually dissolve, the Fe-S phase can be corroded obviously but cannot dissolve, and the Si-O phase has no change. The dissolution of dolomite is mainly controlled by H 2 SO 4 .