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 flotation behavior of pyrrhotite was investigated by using ethyl xanthate as a collector. The results show that pyrrhotite has good floatability from pH 2 to 11, and poor flotability when pH>12. The reagents ad...The flotation behavior of pyrrhotite was investigated by using ethyl xanthate as a collector. The results show that pyrrhotite has good floatability from pH 2 to 11, and poor flotability when pH>12. The reagents adjusting potential are ammonium persulfate （（NH4）2S2O8） and sodium dithionite （Na2S2O4）. The flotation of pyrrhotite is dependent on pulp potential at certain pH value. The potential-pH range for pyrrhotite flotation was established. Cyclic voltammetry and FTIR spectroscopy analysis show that the major adsorption product of ethyl xanthate on pyrrhotite is dixanthogen. The intensity of FTIR signals of dixanthogen adsorbed on pyrrhotite and the anode current of a pyrrhotite electrode and flotation response of pyrrhotite are correlated with pulp potentials.展开更多
基金This project is supported by National Natural Science Foundation of China (No. 30271441) Key Project of Shandong Educational Committee(J01K03)Qingdao Municipal Science & Technology Commission (02-1-KJ-YJ-49).
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.
文摘The flotation behavior of pyrrhotite was investigated by using ethyl xanthate as a collector. The results show that pyrrhotite has good floatability from pH 2 to 11, and poor flotability when pH>12. The reagents adjusting potential are ammonium persulfate （（NH4）2S2O8） and sodium dithionite （Na2S2O4）. The flotation of pyrrhotite is dependent on pulp potential at certain pH value. The potential-pH range for pyrrhotite flotation was established. Cyclic voltammetry and FTIR spectroscopy analysis show that the major adsorption product of ethyl xanthate on pyrrhotite is dixanthogen. The intensity of FTIR signals of dixanthogen adsorbed on pyrrhotite and the anode current of a pyrrhotite electrode and flotation response of pyrrhotite are correlated with pulp potentials.
