High-temperature chlorination of gold with transformation of iron phase

作     者：Zheng-Yao Li Wei-Wei Wang Kun Yue Ming-Xing Chen 

作者机构：School of Civil and Environmental EngineeringUniversity of Science and Technology Beijing 

出 版 物：《Rare Metals》 (稀有金属（英文版）)

年 卷 期：2016年第35卷第11期

页      面：881-886页

核心收录：

学科分类：080603[工学-有色金属冶金] 08[工学] 0806[工学-冶金工程] 

基　　金：financially supported by the National Natural Science Foundation of China (No. 51474018) 

主　　题：Cyanide tailings Chlorination-reduction one-step roasting Transformation of iron phase Gold 

摘      要：Gold in cyanide tailings from Shandong Province is mainly encapsulated by hematite and magnetite at distribution rates of 76.49 % and 10.88 %, ***-reduction one-step roasting of cyanide tailings was conducted under the following conditions： calcium chloride dosage of 6 %, bituminous coal dosage of 30 %, calcium oxide dosage of 10 %（all dosages are *** mass of cyanide tailings） at 1000 ℃ of roasting temperature. X-ray diffraction（XRD）, scanning electron microscopy（SEM）, and chemical-phase analysis were performed to investigate the effects of iron phase transformation on the high-temperature chlorination of *** indicate that the lattice structure of hematite undergoes expansion, pulverization, and reorganization when hematite is reduced to magnetite, which leads to42.03 % gold exposure, and the high-temperature chlorination rate of gold is 41.17 % at the same time. The structure of wustite formed by the reduction in magnetite is porous and loose, and thus 44.02 % of gold is exposed. The high-temperature chlorination rate of gold is increased by41.98 percentage points. When wustite is reduced to metallic iron, 4.42 % of gold is exposed, and the hightemperature chlorination rate of gold is increased by3.38 percentage points. Accordingly, the high-temperature chlorination of gold mainly occurs in two stages, in which Fe_2O_3 is reduced to Fe_3O_4, and Fe_3O_4 is reduced to Fe_xO finally.