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
We systematically investigate the mean pressure measurements at the bottom of a giant static granular column.If a constant overload is placed on top of the bed,the pressure observed displays linearity in overload and ...We systematically investigate the mean pressure measurements at the bottom of a giant static granular column.If a constant overload is placed on top of the bed,the pressure observed displays linearity in overload and non-monotonic in column height.This result is in contradiction with the classical Janssen model.However it is in good agreement with the oriented stress linearity(OSL)model which reveals a local,linear relation between stress components.We conclude that the OSL model works well not only in a tiny static granular column but also in a giant static granular column.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the National Natural Science Foundation of China under Grant Nos 11172039 and 10975014.
文摘We systematically investigate the mean pressure measurements at the bottom of a giant static granular column.If a constant overload is placed on top of the bed,the pressure observed displays linearity in overload and non-monotonic in column height.This result is in contradiction with the classical Janssen model.However it is in good agreement with the oriented stress linearity(OSL)model which reveals a local,linear relation between stress components.We conclude that the OSL model works well not only in a tiny static granular column but also in a giant static granular column.
