Gold bearing pyrite leaching was conducted in H2SO4-Fe2（SO4）3 system at different reaction temperatures,with different ferric ion concentrations,sulfuric acid concentrations and stirring speeds.The leaching kinetics...Gold bearing pyrite leaching was conducted in H2SO4-Fe2（SO4）3 system at different reaction temperatures,with different ferric ion concentrations,sulfuric acid concentrations and stirring speeds.The leaching kinetics and mechanism were studied.When the temperature ranged between 30-75 °C,the pyrite leaching was mainly controlled by chemical reaction with positive correlation to the ferric ion concentration.The activation energy obtained from Arrhenius empirical formula is 51.39 k J/mol.The EDS and XPS analyses suggest that the oxidation of sulfur within pyrite is through a series of intermediate stages,and eventually is oxidized to sulphate accompanied with the formation of element sulfur.This indicates a thiosulfate oxidation pathway of the gold bearing pyrite oxidation in H2SO4-Fe2（SO4）3 system.展开更多
Melamine and poly vinylpyrrolidone （PVP） reacted with neat sulfuric acid readily to form two new organic solid acids namely melamine-（H2SO4）3 and PVP-（H2SO4）n. These solid acids were used for the first nitration...Melamine and poly vinylpyrrolidone （PVP） reacted with neat sulfuric acid readily to form two new organic solid acids namely melamine-（H2SO4）3 and PVP-（H2SO4）n. These solid acids were used for the first nitration of bisphenol A as well as other phenols in the presence of NHaNO3. Mono- and di-nitro bisphenol A have been characterized with IR and ^1H NMR techniques.展开更多
基金Project(51474075)supported by the National Natural Science Foundation of China
文摘Gold bearing pyrite leaching was conducted in H2SO4-Fe2（SO4）3 system at different reaction temperatures,with different ferric ion concentrations,sulfuric acid concentrations and stirring speeds.The leaching kinetics and mechanism were studied.When the temperature ranged between 30-75 °C,the pyrite leaching was mainly controlled by chemical reaction with positive correlation to the ferric ion concentration.The activation energy obtained from Arrhenius empirical formula is 51.39 k J/mol.The EDS and XPS analyses suggest that the oxidation of sulfur within pyrite is through a series of intermediate stages,and eventually is oxidized to sulphate accompanied with the formation of element sulfur.This indicates a thiosulfate oxidation pathway of the gold bearing pyrite oxidation in H2SO4-Fe2（SO4）3 system.
基金financial support for this work from the research affairs of Hamedan University of Medical Sciences, Hamedan,I.R.Iran and partial support of this work by the Research Affairs Office of Bu-Ali Sina University(Grant number 32-1716 entitled development of chemical methods,reagent and molecules.) Hamedan,I.R.Iran
文摘Melamine and poly vinylpyrrolidone （PVP） reacted with neat sulfuric acid readily to form two new organic solid acids namely melamine-（H2SO4）3 and PVP-（H2SO4）n. These solid acids were used for the first nitration of bisphenol A as well as other phenols in the presence of NHaNO3. Mono- and di-nitro bisphenol A have been characterized with IR and ^1H NMR techniques.
