According to the principles of simultaneous chemical equilibrium and electronic charge neutrality, the thermodynamics of Au-NH4Cl-NH3-H2O system was studied by using the exponential computation method and through MATL...According to the principles of simultaneous chemical equilibrium and electronic charge neutrality, the thermodynamics of Au-NH4Cl-NH3-H2O system was studied by using the exponential computation method and through MATLAB programming, and the solid figure of potential-c(NH4Cl)-c(NH4OH) was drawn. The results show that when the sum concentration of Au+ and Au3+ is equal to 5×10-5 mol/L, φ(Au+/Au) is about -0.2 V; when the sum comes up to 0.5 mol/L, the value of φ(Au+/Au) increases to 0.2 V. In this case, φ(O2/OH - ) is as high as 0.7 V. This means that it is feasible to extract gold in this system. In addition, to predict the feasibility of reducing gold from the Au(I)-NH4Cl-NH3-H2O system with copper or zinc powder, the solid figures of potential-c(NH4Cl)-c(NH4OH) for both systems of Cu-NH4Cl-NH3-H2O and Zn-NH4Cl-NH3-H2O were also drawn. The results indicate that both copper and zinc powders can reduce Au+ into metal gold, and zinc powder can also reduce H2O into H2, while copper powder can not. The leaching results of a cuprous gold ore show that the extraction of gold can reach 80% in this system. The preliminary results of reduction with copper and zinc powders show that with deoxygenizing, the reduction effects are relatively good.展开更多
A new stearic acid method(SAM) has been used to prepare ultrafine K2La2Ti3O10 nanocrystalline. Each state of synthesis process was followed by the use of FT IR analysis. The resulting materials have been characterized...A new stearic acid method(SAM) has been used to prepare ultrafine K2La2Ti3O10 nanocrystalline. Each state of synthesis process was followed by the use of FT IR analysis. The resulting materials have been characterized by means of XRD, TEM, BET surface area analysis. The acid exchanging property of the obtained product was also studied. The experimental results showed that comparing with the product of traditional solid state reaction, the particle size of the K2La2Ti3O10 synthesized by SAM is greatly reduced, BET surface area is high(more than 11.83m2· g- 1) and has different acid exchanging properties. It can be easily exfoliated in 2mol· L- 1 HNO3 solution.展开更多
文摘According to the principles of simultaneous chemical equilibrium and electronic charge neutrality, the thermodynamics of Au-NH4Cl-NH3-H2O system was studied by using the exponential computation method and through MATLAB programming, and the solid figure of potential-c(NH4Cl)-c(NH4OH) was drawn. The results show that when the sum concentration of Au+ and Au3+ is equal to 5×10-5 mol/L, φ(Au+/Au) is about -0.2 V; when the sum comes up to 0.5 mol/L, the value of φ(Au+/Au) increases to 0.2 V. In this case, φ(O2/OH - ) is as high as 0.7 V. This means that it is feasible to extract gold in this system. In addition, to predict the feasibility of reducing gold from the Au(I)-NH4Cl-NH3-H2O system with copper or zinc powder, the solid figures of potential-c(NH4Cl)-c(NH4OH) for both systems of Cu-NH4Cl-NH3-H2O and Zn-NH4Cl-NH3-H2O were also drawn. The results indicate that both copper and zinc powders can reduce Au+ into metal gold, and zinc powder can also reduce H2O into H2, while copper powder can not. The leaching results of a cuprous gold ore show that the extraction of gold can reach 80% in this system. The preliminary results of reduction with copper and zinc powders show that with deoxygenizing, the reduction effects are relatively good.
文摘A new stearic acid method(SAM) has been used to prepare ultrafine K2La2Ti3O10 nanocrystalline. Each state of synthesis process was followed by the use of FT IR analysis. The resulting materials have been characterized by means of XRD, TEM, BET surface area analysis. The acid exchanging property of the obtained product was also studied. The experimental results showed that comparing with the product of traditional solid state reaction, the particle size of the K2La2Ti3O10 synthesized by SAM is greatly reduced, BET surface area is high(more than 11.83m2· g- 1) and has different acid exchanging properties. It can be easily exfoliated in 2mol· L- 1 HNO3 solution.
