Coupling leaching of sphalerite concentrate
(1. Institute of Process Engineering, Chinese Academy of Sciences,
Beijing 100080, China;
2. Engineering Command Institute of Chemical Defence, Beijing 102205, China)
Beijing 100080, China;
2. Engineering Command Institute of Chemical Defence, Beijing 102205, China)
Abstract: Coupling process of sphalerite concentrate leaching in H2SO4-HNO3 and tetrachloroethylene extracting of sulfur was investigated. Effects of leaching temperature, leaching time, mass ratio of liquid to solid and tetrachloroethylene addition on zinc leaching processes were examined separately. SEM images of sphalerite concentrate and residues were performed by using JEM-6700F field emission scanning electron microscope. The relationship between the number of recycling and extraction ratio of zinc was studied. The results indicate that 99.6% zinc is obtained after leaching for 3h at 85℃ and pressure of 0.1MPa O2, with 20g sphalerite concentrate in 200mL leaching solution containing 2.0mol/L H2SO4 and 0.2mol/L HNO3, in the presence of 10mL C2Cl4. The leaching time of zinc is 50% shorter than that in the common leaching. The coupling effect is distinct. The recycled C2Cl4 exerts little influence on extraction ratio of zinc.
Key words: sphalerite; H2SO4-HNO3; coupling leaching