- 期刊
Temperature Effect on Gold Extraction by Dibutyl Carbitol
利用雙丁基卡必醇萃取金之溫度效應
摘要
Temperature effect on gold extraction from aqua regia solution with dibutyl carbitol (DBC) has been studied in detail. The percentage extraction of gold and the impurity, tin, decrease with increasing temperature. During scrubbing, gold concentration in the scrubbed solution increases with increasing temperature. Whereas, the amount of tin in the scrubbed solution decreases with increasing temperature. Results also indicate that temperature does not affect other impurities, such as tellurium, arsenic, antinomy and iron, on gold extraction and scrubbing. Thermodynamic data, the changes of enthalpy, Gibb's free energy and entropy at 25°C are found to be equal to -84.24 Kj mole^(-1),-8.51 Kj mole^(-1),-0.25 kj mole^(-1) °K^(-1), respectively. The negative change of enthalpy indicates the gold extraction is exothermic, the negative value of ∆G° reflects that the equilibrium yield of the gold extraction is high, and the negative change of entropy indicates that gold is being transferred from a disordered state to one of greater order.
關鍵字
無資料並列摘要
本文係研究溫度對利用雙丁基卡必醇（Dibutyl Carbitol，DBC）自王水溶液中萃取金之影響，由實驗結果顯示，金與溶液中雜質—錫之萃取百分比隨溫度昇高而降低。在洗滌時，金在洗滌液之濃度隨溫度昇高而增加，但錫之濃度則反之。另外，溫度對進料溶液中之其它雜質如鍗、鉮、銻與鐵在萃取與洗滌時，均無影響。同時，由實驗數據計算，在25℃下，萃取金之焓變化為-82.24 KJ mole^(-1)。Gibbs自由能為-8.51 KJ mole^(-1)，而熵為-0.25 KJ mole^(-1) °K^(-1)，焓變化為負值表示DBC萃取金為放熱反應，自由能為負值表示萃取金之平衡值很高，而負熵值則表示萃取金時，金從混亂狀態轉化成秩序狀態。