In this paper,sulfidation mechanism of cerussite in the presence of sulphur at high temperatures was investigated based on micro-flotation,X-ray powder diffractometry(XRD),electron probe microanalysis(EPMA)and X-ray p...In this paper,sulfidation mechanism of cerussite in the presence of sulphur at high temperatures was investigated based on micro-flotation,X-ray powder diffractometry(XRD),electron probe microanalysis(EPMA)and X-ray photoelectron spectroscopy(XPS).The micro-flotation test results showed that flotation recovery of the treated cerussite increased to above 80%under a suitable flotation condition.It was found that the S/PbCO3 mole ratio and pH obviously affected flotation recovery.XRD analysis results confirmed that the cerussite was decomposed into massicot and then was transformed into mainly PbS and PbO·PbSO4 after sulfidation roasting.EPMA analysis results demonstrated that surface of the obtained massicot was smooth,but surface of the artificial galena was rough and even porous.Content of oxygen decreased,whereas content of sulphur increased with an increase in the S/PbCO3 mole ratio.XPS analysis results revealed that various lead-bearing species,including mainly PbS,PbSO4 and PbO·PbSO4,were generated at the surface.Formation of PbS was advantageous to flotation of the treated cerussite.Based on these results,a reaction model of the cerussite sulfurized with sulphur was proposed.展开更多
Evaluation of flotation behavior, solution measurements, and surface analyses were performed to investigate the effects of chloride ion addition on the sulfidization of cerussite in this study. Micro-flotation tests i...Evaluation of flotation behavior, solution measurements, and surface analyses were performed to investigate the effects of chloride ion addition on the sulfidization of cerussite in this study. Micro-flotation tests indicate that the addition of chloride ions prior to sulfidization can significantly increase the flotation recovery of cerussite, which is attributed to the formation of more lead sulfide species on the mineral surface. Solution measurement results suggest that the addition of chloride ions prior to sulfidization induces the transformation of more sulfide ions from pulp solution onto the mineral surface by the formation of more lead sulfide species. X-ray diffraction and energy-dispersive spectroscopy indicate that more lead sulfide species form on the mineral surface when chloride ions are added prior to sulfidization. These results demonstrate that the addition of chloride ions prior to sulfidization can significantly improve the sulfidization of cerussite, thereby enhancing the flotation performance.展开更多
Elemental lead is a known toxic metal that can pose threats to human health and can be found in a variety of sources including drinking water at very low level concentrations (i.e. μg/L range). Destabilization of the...Elemental lead is a known toxic metal that can pose threats to human health and can be found in a variety of sources including drinking water at very low level concentrations (i.e. μg/L range). Destabilization of the corrosion scale at the inner layer of pipeline is the major source of lead in drinking water. Chemical properties of the water passing through the distribution system such as pH, alkalinity, chlorine content, oxidation reduction potential (ORP) and natural organic matters will affect the formation and/or destabilization of the corrosion scale. This research examines the impact of pH values (7.0 - 9.5), temperatures (5°C vs 20°C) and alkalinity levels (moderate vs low), in the presence of chlorine, on dissolution of hydrocerussite and cerussite in drinking water by various sets of batch dissolution experiments. The results showed dissolution of cerussite and hydrocerussite was not impacted significantly by pH ranging 7.0 - 9.5. In addition, and somewhat surprisingly, cold temperature (5°C) and moderate alkalinity showed a great influence on decreasing the solubility of lead species.展开更多
A new synthetic reagent DPTUHP [diphenyl α-（3-phenylthioureido） hexylpbosphonate] containing a hydrocarbon chain nonpolar group, a thioureido, and a phosphonate easter chelating group, has proven to be an effective...A new synthetic reagent DPTUHP [diphenyl α-（3-phenylthioureido） hexylpbosphonate] containing a hydrocarbon chain nonpolar group, a thioureido, and a phosphonate easter chelating group, has proven to be an effective collector for the flotation of cerussite mineral. The synthetic method utilized the Mannich-type reaction of an N-monosubstituted thiourea, an aldehyde, and triphenyl phosphate in glacial acetic acid solution. The experimental results of flotation of the cerussite mineral show that the collector has stronger collecting ability and higher selectivity in a neutral and a slightly alkaline medium, especially in the pulp of pH=8. Using the measurements by infrared spectroscopy （IR） and X-ray photoelectron spectroscopy （XPS） of the cerussite mineral, the collector, as well as the cerussite treated with the collector, the flotation mechanism of cerussite has been discussed. It is concluded that the adsorption of collector on cerussite is a chemical adsorption through the electron donor atoms of the collector chelating the Pb （ Ⅱ ） of cerussite to form chelate.展开更多
基金Project(51964027)supported by the National Natural Science Foundation of ChinaProject(2017FB084)supported by the Yunnan Province Applied Basic Research Project,ChinaProject(2019J0037)supported by the Education Department of Yunnan Province,China。
文摘In this paper,sulfidation mechanism of cerussite in the presence of sulphur at high temperatures was investigated based on micro-flotation,X-ray powder diffractometry(XRD),electron probe microanalysis(EPMA)and X-ray photoelectron spectroscopy(XPS).The micro-flotation test results showed that flotation recovery of the treated cerussite increased to above 80%under a suitable flotation condition.It was found that the S/PbCO3 mole ratio and pH obviously affected flotation recovery.XRD analysis results confirmed that the cerussite was decomposed into massicot and then was transformed into mainly PbS and PbO·PbSO4 after sulfidation roasting.EPMA analysis results demonstrated that surface of the obtained massicot was smooth,but surface of the artificial galena was rough and even porous.Content of oxygen decreased,whereas content of sulphur increased with an increase in the S/PbCO3 mole ratio.XPS analysis results revealed that various lead-bearing species,including mainly PbS,PbSO4 and PbO·PbSO4,were generated at the surface.Formation of PbS was advantageous to flotation of the treated cerussite.Based on these results,a reaction model of the cerussite sulfurized with sulphur was proposed.
基金financially supported by the National Natural Science Foundation of China (Nos. 51464029 and 51304089)the Analysis and Testing Foundation of Kunming University of Science and Technology (Nos. 20130534 and 20140876)the Academic New Artist Award for Doctoral Post Graduate in Yunnan Province of China (2014)
文摘Evaluation of flotation behavior, solution measurements, and surface analyses were performed to investigate the effects of chloride ion addition on the sulfidization of cerussite in this study. Micro-flotation tests indicate that the addition of chloride ions prior to sulfidization can significantly increase the flotation recovery of cerussite, which is attributed to the formation of more lead sulfide species on the mineral surface. Solution measurement results suggest that the addition of chloride ions prior to sulfidization induces the transformation of more sulfide ions from pulp solution onto the mineral surface by the formation of more lead sulfide species. X-ray diffraction and energy-dispersive spectroscopy indicate that more lead sulfide species form on the mineral surface when chloride ions are added prior to sulfidization. These results demonstrate that the addition of chloride ions prior to sulfidization can significantly improve the sulfidization of cerussite, thereby enhancing the flotation performance.
文摘Elemental lead is a known toxic metal that can pose threats to human health and can be found in a variety of sources including drinking water at very low level concentrations (i.e. μg/L range). Destabilization of the corrosion scale at the inner layer of pipeline is the major source of lead in drinking water. Chemical properties of the water passing through the distribution system such as pH, alkalinity, chlorine content, oxidation reduction potential (ORP) and natural organic matters will affect the formation and/or destabilization of the corrosion scale. This research examines the impact of pH values (7.0 - 9.5), temperatures (5°C vs 20°C) and alkalinity levels (moderate vs low), in the presence of chlorine, on dissolution of hydrocerussite and cerussite in drinking water by various sets of batch dissolution experiments. The results showed dissolution of cerussite and hydrocerussite was not impacted significantly by pH ranging 7.0 - 9.5. In addition, and somewhat surprisingly, cold temperature (5°C) and moderate alkalinity showed a great influence on decreasing the solubility of lead species.
文摘A new synthetic reagent DPTUHP [diphenyl α-（3-phenylthioureido） hexylpbosphonate] containing a hydrocarbon chain nonpolar group, a thioureido, and a phosphonate easter chelating group, has proven to be an effective collector for the flotation of cerussite mineral. The synthetic method utilized the Mannich-type reaction of an N-monosubstituted thiourea, an aldehyde, and triphenyl phosphate in glacial acetic acid solution. The experimental results of flotation of the cerussite mineral show that the collector has stronger collecting ability and higher selectivity in a neutral and a slightly alkaline medium, especially in the pulp of pH=8. Using the measurements by infrared spectroscopy （IR） and X-ray photoelectron spectroscopy （XPS） of the cerussite mineral, the collector, as well as the cerussite treated with the collector, the flotation mechanism of cerussite has been discussed. It is concluded that the adsorption of collector on cerussite is a chemical adsorption through the electron donor atoms of the collector chelating the Pb （ Ⅱ ） of cerussite to form chelate.
