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.
