Stability constants of Sb5+ with Cl- and thermodynamics of Sb-S-Cl-H2O system involving complex behavior of Sb with Cl
(1. College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China;
2. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
3. School of Metallurgical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China;
4. College of Metallurgy and Material Engineering, Hunan University of Technology, Zhuzhou 412007, China)
2. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
3. School of Metallurgical Engineering, Jiangxi University of Science and Technology, Ganzhou 341000, China;
4. College of Metallurgy and Material Engineering, Hunan University of Technology, Zhuzhou 412007, China)
Abstract: The stability constants of Sb5+ with Cl- as well as thermodynamics of the Sb-S-Cl-H2O system were calculated. The stability constants of Sb5+ with Cl- were obtained by theoretical calculations of the absorbance of a Sb5+-containing solution at different Cl- concentrations, which was detected by spectrophotometric analysis at certain wavelengths of light (380 nm). The logarithmic values versus 10 of stability constants of Sb5+ with Cl- were 1.795, 3.150, 4.191, 4.955, 5.427 and 5.511, respectively, and partly filled the data gaps in the hydrometallurgy of antimony. The presence and distribution of pentavalent antimony compounds under different conditions were analyzed based on equilibrium calculations. Thermodynamic equilibrium calculations were performed for Sb-S-Cl-H2O system, which included the complex behavior of Sb with Cl, and the equilibrium equations of related reactions in this system were integrated into the potential-pH diagram.
Key words: complex behavior; stability constant; thermodynamics; Sb-S-Cl-H2O system