摘要
Na2SiO3 and Na2SeO3 were chosen as stable reagents of alkaline thiourea solution substituting Na2SO3, according to the structure-property relationship between the stability of alkaline thiourea and the structure of thiourea and sulfite ion, and the effect of the stable reagents on stability of alkaline thiourea was investigated. The results show that contrary to Na2SeO3, Na2SO3 and Na2SiO3 affect the stability of alkaline thiourea solution remarkably. The stable effect of Na2SiO3 on alkaline thiourea is obviously better than that of Na2SO3. The stable reagents Na2SO3 and Na2SiO3 decrease the decomposition rate of alkaline thiourea solution greatly, and the decomposition rate of alkaline thiourea reduces from （72.5%） to （33.8%） with addition of (0.3 mol·L-1) Na2SiO3. Dissolution currents of gold in the alkaline thiourea solution containing Na2SO3 and Na2SiO3 are （2.0） (mA·cm-2) and （3.5） (mA·cm-2) at the potential of 0.42 V, respectively, and Na2SO3 is consumed excessively due to the oxidation reaction of Na2SO3 occurring in the studied potential range. Na2SiO3 is an efficient stable reagent of alkaline thiourea solution, and gold dissolution is accelerated much more obviously by Na2SiO3 than by Na2SO3.
Na_2SiO_3 and Na_2SeO_3 were chosen as stable reagents of alkaline thioureasolution substituting Na_2SO_3, according to the structure-property relationship between thestability of alkaline thiourea and the structure of thiourea and sulfite ion, and the effect of thestable reagents on stability of alkaline thiourea was investigated. The results show that contraryto Na_2SeO_3, Na_2SO_3 and Na_2SiO_3 affect the stability of alkaline thiourea solution remarkably.The stable effect of Na_2SiO_3 on alkaline thiourea is obviously better than that of Na_2SO_3. Thestable reagents Na_2SO_3 and Na_2SiO_3 decrease the decomposition rate of alkaline thiourea solutiongreatly, and the decomposition rate of alkaline thiourea reduces from 72.5% to 33. 8% with additionof 0. 3 mol·L^(-1) Na_2SiO_3. Dissolution currents of gold in the alkaline thiourea solutioncontaining Na_2SO_3 and Na_2SiO_3 are 2.0 mA ·cm^(-2) and 3.5 mA·cm^(-2) at the potential of 0. 42V, respectively, and Na_2SO_3 is consumed excessively due to the oxidation reaction of Na_2SO_3occurring in the studied potential range. Na_2SiO_3 is an efficient stable reagent of alkalinethiourea solution, and gold dissolution is accelerated much more obviously by Na_2SiO_3 than byNa_2SO_3.
基金
Project( 5 0 0 0 4 0 0 9)supportedbytheNationalNaturalScienceFoundationofChina
