Leaching of low grade zinc oxide ores in Ida2−−H2O system
(School of Metallurgical Science and Engineering, Central South University. Changsha 410083, China)
Abstract: Ida2−−H2O system (iminodiacetate aqueous solution) was used to leach a low grade zinc oxide ore for Zn extraction. The effects of leaching time, liquid-solid ratio (L/S), total concentration of Ida2− ([Ida2−]T), leaching temperature and pH on Zn leaching recovery and the dissolution of impurities such as Ca, Mg, Cu, Ni, Fe, Pb and Cd were investigated. Results show that Ca, Mg and Fe in ores were hardly dissolved in alkalescent iminodiacetate aqueous solution, while valuable metals such as Cu, Ni, Pb and Cd were partly dissolved into leaching liquor with Zn. The recovery of Zn reaches 76.6% when the ores were leached for 4 h at 70 °C by 0.9 mol/L iminodiacetate aqueous solution with pH of 8 and L/S of 5:1.
Key words: Ida2−; zinc oxide ore; leaching