The corrosive electrochemistry of jamesonite (Pb4FeSb6S14) was studied by the electrochemical methods of cyclic voltammetry, polarization, and AC impedance. The electrochemical processes of jamesonite were controlled ...The corrosive electrochemistry of jamesonite (Pb4FeSb6S14) was studied by the electrochemical methods of cyclic voltammetry, polarization, and AC impedance. The electrochemical processes of jamesonite were controlled by the corrosive reactions, growth of the metal-deficient and sulfur-riched layer, passivation and breakdown of elemental sulfur film on the electrode surface. The corrosive potential(φcorr) moves negatively, its corrosive current increases, and hydroxyl action becomes stronger with the rising pH value. The charge transfer resistance increases and the capacitance decreases due to the gradual growth of the metal-deficient and sulfur-riched layer on the mineral surface from -378 to 122 mV （vs SHE）. Element sulfur layer is formed at the potential of 122 mV. The charge transfer resistance increases and its capacitance rises slowly due to the gradual breakdown of sulfur film at voltage from 222 mV to 422 mV. S2O2-3 and SO2-4 ions occur when the electrode potential is over 422 mV. Under basic condition, the hydrophobic hydroxyl precipitate occurs on jamesonite surface, so that its collectorless floatability is poor. Under the condition of pH 6.86, it can be deduced that the potential range of collectorless floatability of jamesonite is from 22 to 422 mV due to the passive action of the hydrophilic sulfur on jamesonite surface, and its optimum range of floatable potential is between 122 and 322 mV.展开更多
The collector and collectorless notation of sphalerite by potential control,called potential-controlled flotation(PCF),have been investigated in this paper.The results have shown that the oxidative environment of flot...The collector and collectorless notation of sphalerite by potential control,called potential-controlled flotation(PCF),have been investigated in this paper.The results have shown that the oxidative environment of flotation pulp or higher pulp potential could improve and activate the PCF of sphalerite,which was depressed under reducing conditions or lower pulp potential.The mechanisms of PCF have been simply discussed.展开更多
Original potential flotation (OPF) technology, which controls potential by chemical atomsphere resulted from various redox reactions in grinding flotation system, but neither through the use of redox reagents nor thro...Original potential flotation (OPF) technology, which controls potential by chemical atomsphere resulted from various redox reactions in grinding flotation system, but neither through the use of redox reagents nor through the application of potentials from an external source, was proposed. For lead zinc iron sulphide minerals flotation system, the relationship among technological parameters such as pH, E op , collectors and flotaion time, was studied. The optimum conditions for the selective flotation of galena from the pb Zn Fe sulfide ores were: pH of 12.5～12.8,the pulp potential of 150～180 mV and with diethyldithioncarbamate (DDTC) as collector.展开更多
文摘The corrosive electrochemistry of jamesonite (Pb4FeSb6S14) was studied by the electrochemical methods of cyclic voltammetry, polarization, and AC impedance. The electrochemical processes of jamesonite were controlled by the corrosive reactions, growth of the metal-deficient and sulfur-riched layer, passivation and breakdown of elemental sulfur film on the electrode surface. The corrosive potential(φcorr) moves negatively, its corrosive current increases, and hydroxyl action becomes stronger with the rising pH value. The charge transfer resistance increases and the capacitance decreases due to the gradual growth of the metal-deficient and sulfur-riched layer on the mineral surface from -378 to 122 mV （vs SHE）. Element sulfur layer is formed at the potential of 122 mV. The charge transfer resistance increases and its capacitance rises slowly due to the gradual breakdown of sulfur film at voltage from 222 mV to 422 mV. S2O2-3 and SO2-4 ions occur when the electrode potential is over 422 mV. Under basic condition, the hydrophobic hydroxyl precipitate occurs on jamesonite surface, so that its collectorless floatability is poor. Under the condition of pH 6.86, it can be deduced that the potential range of collectorless floatability of jamesonite is from 22 to 422 mV due to the passive action of the hydrophilic sulfur on jamesonite surface, and its optimum range of floatable potential is between 122 and 322 mV.
基金supported by the National Natural Science Foundation
文摘The collector and collectorless notation of sphalerite by potential control,called potential-controlled flotation(PCF),have been investigated in this paper.The results have shown that the oxidative environment of flotation pulp or higher pulp potential could improve and activate the PCF of sphalerite,which was depressed under reducing conditions or lower pulp potential.The mechanisms of PCF have been simply discussed.
文摘Original potential flotation (OPF) technology, which controls potential by chemical atomsphere resulted from various redox reactions in grinding flotation system, but neither through the use of redox reagents nor through the application of potentials from an external source, was proposed. For lead zinc iron sulphide minerals flotation system, the relationship among technological parameters such as pH, E op , collectors and flotaion time, was studied. The optimum conditions for the selective flotation of galena from the pb Zn Fe sulfide ores were: pH of 12.5～12.8,the pulp potential of 150～180 mV and with diethyldithioncarbamate (DDTC) as collector.
