| Abstrakt: |
Abstract—The base-metal (70–75 wt %) and tin–sulfide (10–15 wt %) deposits are the main indium suppliers in the world. However, the causes and conditions of In accumulation in the ores of these deposits are still unclear. To shed light on this problem, we simulated the physicochemical conditions of formation of base metal and tin–sulfide ores with elevated indium content. For this purpose, the average composition of ore–bearing hydrothermal solutions and parameters of ore precipitation at these deposits were determined using available literature data. Based on these data, obtained standard thermodynamic characteristics of chloride indium species ( InCl3, InClOH+), coefficients required for calculations at elevated temperature and pressure, the formation of elevated indium contents in these ores was numerically simulated using "Gem–Selektor-3" and "Chiller" softwares. The results of thermodynamic modeling of the formation of quartz–cassiterite and tin–sulfide ores show that the higher In contents in tin–sulfide ores are related to their formation from acid (pH 4.3), high–chloride (6.6 m) solutions, which contain In (0.002 m) in form of (InCl3aq). The quartz–cassiterite ores were formed from near–neutral (pH 5.3), low–chloride (1.02 m) solution, in which In occurred as hydroxocomplexes InO2H and in concentrations no more than 0.00004 m, which, respectively, determined its low contents in these ores. Computer modeling of the formation of indium–bearing sulfide-base metal and barite-base metal deposits shows that they were formed form high–temperature chloride (1.3–4.3 m) hydrothermal solutions of near–neutral composition (pH 5.8–6). The main In speciations are hydroxocomplexes InO2H and , which provide In concentrations of 5–9 × 10–5 m). However, due to the low indium concentrations in hydrothermal solutions, the forming sulfide minerals (sphalerite, pyrite, and chalcopyrite) differ in the lower indium contents compared to the minerals of tin–sulfide ores. [ABSTRACT FROM AUTHOR] |
Full text from SpringerLink