E-pH diagram of ZnS-H_2O system during high pressure leaching of zinc sulfide

The values of GΘ,EΘ or pH from 110 to 160℃ were calculated and the relevant potential expressions were obtained.E-pH diagrams of ZnS-H2O system at oxygen partial pressure of 0.8 MPa,ionic activity of 1.0 and different temperatures were drawn through thermodynamical calculation.With the temperature increasing,the stable regions of S and Zn(Ⅱ) in the E-pH diagrams become gradually larger,but the amplification decreases over 150℃.The impacts of leaching parameters,such as temperature,liquid to solid ratio,initial acidic concentration,leaching time,oxygen partial pressure and stirring speed on the leaching rate of Zn(Ⅱ) and conversion rate of S in the single factor of high pressure leaching experiment of ZnS in autoclave,were studied.The leaching residue was examined by X-ray fluorescence(XRF) chemical composition identification and X-ray diffraction(XRD) phase identification,and the content of the leaching solution was tested by inductively coupled plasma-atomic emission spectrometry(ICP).The experimental results indicate that the leaching rate of zinc increases from 60.05% to 97.85% and the conversion rate of sulfur increases from 38.90% to 80.92% with the temperature increasing from 110℃ to 150℃,5:1 of liquid-to-solid ratio,150 g/L of initial acidic concentration,120 min of leaching time,0.8 MPa of oxygen partial pressure,and 480 r/min of stirring speed,which tend to be stable over 150℃.The experimental results correspond with theoretical calculation.

盐酸浸出氧化锑泥制备SbCl_3

利用HSC6.0软件分别绘制不同温度、氯离子浓度下的Sb-Cl-H_2O的E-pH图,结果表明:在Sb-Cl-H2O体系中,溶液温度、酸度和氯离子浓度是SbCl_3稳定存在的主要因素。用盐酸浸出氧化锑泥,实验结果表明:当盐酸加入量(盐酸体积/氧化锑泥质量L/S)为3,常温下浸出4 h,氧化锑泥的浸出率可达94%以上。浸出渣的XRD分析表明:浸出渣主要是NaCl,随着盐酸量增加,渣中锑含量逐渐降低。