Features of Shaimerden Deposit Oxidized Zinc Ore Leaching

The object studied is Shaimerden oxidized zinc ore deposit containing zinc, lead, copper, iron, calcium, magnesium, aluminum, manganese and silicon. Chemical and mineralogical composition of the ore are investigated. It is established that ore coarse fraction contains more zinc carbonate and less zinc silicate compared with undersize particles. In addition, ore coarse fraction is richer in residual forms (nontronite, sphalerite) hardly soluble in sulphuric acid solution. Thermodynamic analysis of probable transformations during leaching is carried out, kinetics of coarse fraction and undersize particles of ore leaching is studied, and Pourbaix diagrams are plotted for analysis of processes occurring at a phase interface during leaching of oxidized zinc ore. Studies for stripping oxidized zinc ore are carried out on large (–20+1 mm) and small (–1+0 mm) fractions. Optimum leaching parameters are established for fine and coarse ore fractions: sulfuric acid concentration and process temperature and duration (C(H₂SO₄) = 150–160 g/liter, temperature 60°C, leaching time 60 min). Dependences are determined for the degree of zinc extraction into solution on sulphuric acid concentration, temperature, and leaching duration for coarse and fine ore factions.