Sorption method is used for analysis of teclmological, geological and hydro-chemical samples with low content of precious metals and chemical pre-concentration of technological solution. Synthesized silicon-organic po...Sorption method is used for analysis of teclmological, geological and hydro-chemical samples with low content of precious metals and chemical pre-concentration of technological solution. Synthesized silicon-organic polymer containing thiocarbamide group, which named poly[bis -N,N＇-（3-silsesquioxanilpropyl）-thiocarbamide]-（PSTM-3T） was used in this investigation. Sorption of Au（III） and Ag（I） ions from aqueous solutions of nitric acid has been studied using the silicon-organic polymer （PSTM-3T） under different experimental conditions. Better sorption was obtained at temperature 55 ℃, 3 mol/L of nitric acid solution and contact time 300 min and 240 min for Ag（I） and Au（Ⅲ）.Thermodynamic parameters were calculated by Van＇t Hoffequation. The negative values of△G0 at different temperatures indicate the feasibility of the process and the values become more negative with increase in temperature. The positive values of △H0 and AS0 indicate that the sorption process is endothermic and determine the disorderliness of the sorption at solid-liquid interface. Experimental data were evaluated to find out kinetic characteristics and found that the sorption of Au（Ⅲ） followed pseudo-second order model and the sorption of Ag（Ⅰ） followed pseudo-first order model. The sorption capacity increased with the increase in temperature and reached maximum value at 323 K and 328 K for Au（Ⅲ） and Ag（Ⅰ）. The maximum sorption capacity of PSTM-3T for Au（Ⅲ） and Ag（Ⅰ） evaluated 333 and 129 mg/g.展开更多
文摘Sorption method is used for analysis of teclmological, geological and hydro-chemical samples with low content of precious metals and chemical pre-concentration of technological solution. Synthesized silicon-organic polymer containing thiocarbamide group, which named poly[bis -N,N＇-（3-silsesquioxanilpropyl）-thiocarbamide]-（PSTM-3T） was used in this investigation. Sorption of Au（III） and Ag（I） ions from aqueous solutions of nitric acid has been studied using the silicon-organic polymer （PSTM-3T） under different experimental conditions. Better sorption was obtained at temperature 55 ℃, 3 mol/L of nitric acid solution and contact time 300 min and 240 min for Ag（I） and Au（Ⅲ）.Thermodynamic parameters were calculated by Van＇t Hoffequation. The negative values of△G0 at different temperatures indicate the feasibility of the process and the values become more negative with increase in temperature. The positive values of △H0 and AS0 indicate that the sorption process is endothermic and determine the disorderliness of the sorption at solid-liquid interface. Experimental data were evaluated to find out kinetic characteristics and found that the sorption of Au（Ⅲ） followed pseudo-second order model and the sorption of Ag（Ⅰ） followed pseudo-first order model. The sorption capacity increased with the increase in temperature and reached maximum value at 323 K and 328 K for Au（Ⅲ） and Ag（Ⅰ）. The maximum sorption capacity of PSTM-3T for Au（Ⅲ） and Ag（Ⅰ） evaluated 333 and 129 mg/g.
