The flotation of hemimorphite using the S(Ⅱ)–Pb(Ⅱ)–xanthate process,which includes sulfidization with sodium sulfide,activation by lead cations,and subsequent flotation with xanthate,was investigated.The flotation...The flotation of hemimorphite using the S(Ⅱ)–Pb(Ⅱ)–xanthate process,which includes sulfidization with sodium sulfide,activation by lead cations,and subsequent flotation with xanthate,was investigated.The flotation results indicated that hemimorphite floats when the S(Ⅱ)–Pb(Ⅱ)–xanthate process is used; a maximum recovery of approximately 90% was obtained.Zeta-potential,contact-angle,scanning electron microscopy–energy-dispersive spectrometry(SEM–EDS),and diffuse-reflectance infrared Fourier transform spectroscopy(DRIFTS) measurements were used to characterize the activation products on the hemimorphite surface and their subsequent interaction with sodium butyl xanthate(SBX).The results showed that a Zn S coating formed on the hemimorphite surface after the sample was conditioned in an Na2 S solution.However,the formation of a Zn S coating on the hemimorphite surface did not improve hemimorphite flotation.With the subsequent addition of lead cations,Pb S species formed on the mineral surface.The formation of the Pb S species on the surface of hemimorphite significantly increased the adsorption capacity of SBX,forming lead xanthate(referred to as chemical adsorption) and leading to a substantial improvement in hemimorphite flotation.Our results indicate that the addition of lead cations is a critical step in the successful flotation of hemimorphite using the sulfidization–lead ion activation–xanthate process.展开更多
The direct sulfidization of cuprite is inefficient because cuprite is a copper-oxide mineral with a strong surface hydrophilicity.In this study,oxidant was used to modify cuprite surfaces to regulate the sulfidization...The direct sulfidization of cuprite is inefficient because cuprite is a copper-oxide mineral with a strong surface hydrophilicity.In this study,oxidant was used to modify cuprite surfaces to regulate the sulfidization of cuprite.Microflotation tests showed that the flotation recovery of pre-oxidized cuprite was nearly25% higher than that of direct sulfidization flotation,which indicates that the cuprite surface activity was enhanced after pre-oxidation by Cu(Ⅰ) species(weak affinity with sulfur ions) transformation to Cu(Ⅱ)species(strong affinity with sulfur ions).Zeta potential,scanning electron microscopy-energy dispersive X-ray spectroscopy,X-ray photoelectron spectroscopy,and time-of-flight secondary ion mass spectrometry results showed that pre-oxidation improved cuprite sulfidization and promoted the formation of copper-sulfide species on the cuprite surfaces.The mineral surface stability and thus,xanthate species adsorption on the cuprite surfaces were improved.The surface-adsorption measurements and infrared spectroscopy showed that a large amount of xanthate species was adsorbed onto the sulfidized cuprite surfaces after pre-oxidation,which enhanced the cuprite hydrophobicity and improved the cuprite flotation.展开更多
The removal of hydrogen sulfide from gas plays an important role in rational utilization of resources and environ- mental protection. In this paper, the process of hydrogen sulfide removal by wet oxidation method in a...The removal of hydrogen sulfide from gas plays an important role in rational utilization of resources and environ- mental protection. In this paper, the process of hydrogen sulfide removal by wet oxidation method in a rotating packed bed was investigated in a scale for treating 10 000 Nm3/h of gas. On the basis of studying the influence of the species and con- centration of alkali source, the liquid/gas volume ratio, the high gravity factor, and the hydrogen sulfide content in feed gas on the desulfurization effect, the suitable technological conditions were obtained. The hydrogen sulfide removal efficiency could reach 98.0% under these conditions. The results of continuous operation of process facilities showed that the high gravity method has many merits including higher desulfurization rate, good stability in operation, lower liquid/gas volume ratio, greater operation elasticity, and apparent energy saving effects.展开更多
A flow-based iodometric extraction method for the determination of selenium sulfide was developed and applied to cosmeceutical products. Iodine which was generated from the reduction of selenium（IV） ions by iodide i...A flow-based iodometric extraction method for the determination of selenium sulfide was developed and applied to cosmeceutical products. Iodine which was generated from the reduction of selenium（IV） ions by iodide ion was on-line extracted using a polypropylene HFM （hollow fiber membrane） liquid extraction technique. The HFM extraction unit was constructed and used to support an organic solvent （hexane） and separate between the organic phase and aqueous phase. The resulting purple extract was carried to a fiber optic spectrophotometric detector for the measurement at 521 nm. Parameters which affected the extraction efficiency, sensitivity and sample throughput such as iodide （selenium molar ratio, extraction time and washing time between the cycles） were investigated and optimized. A linear dynamic range of 80-373 mg.Lt selenium solution was obtained with an extraction time of 60 sec. The total analysis time including washing was about 180 sec which provided a sample throughput of approximately 20 samples＇hr1 and excluded the sample pre-treatment. The recoveries for the determination of selenium in the forms of selenium dioxide and selenium sulfide were in the range of 103%-104% with 1%-3% RSD （relative standard deviation）. The relative errors of this method which was applied for determination of selenium sulfide levels in an anti-dandruff shampoo and a cosmeceutical bead sample were both less than 2.5%.展开更多
A simple and fast ultraviolet spectrophotometric method was used to determineselenium (Ⅳ) through the formation, separaion and quantitative determination of potassium butylxanthae -selenium complex. The complex ab...A simple and fast ultraviolet spectrophotometric method was used to determineselenium (Ⅳ) through the formation, separaion and quantitative determination of potassium butylxanthae -selenium complex. The complex absorbed light sharply at 375 nm. The optimum acidity ofthe complex formation was between pH 3.4 - 4.0. The absorption value was no change in 120 minutesafter the comlex was extracted by Carbon tetraChioride. The sensitivity of the colour reation was 0.2ng cm-2, The content of selenimp (Ⅳ) was within 0-30 μg and linear rclation was good,Y=0.07X＋0.025, relevent coefficient r＝0.9997. A great quantity of I, Cu, Co, the and SO4-2, PO4-3contained in .the Sample had no effect on the results ofdetenninion when seldsum was determined.When content of Fe was over l00gμg/ml and Zn was over 180μg/ml, there was diotance to the determination, but the disturbance was rem0ved by adding EDTA. When making use of the method todetermine containin seldsum additivef Cv =6.85, rate of recovery was 97.2%, wild jujubef;Cv=3.22,rate of recovery was 90. 1%, soil Samlef Cv=4.64, rate of recovery was 86.2%. The method for sensitivity measured was apprtoate to 2, 3-diamino naphthalene (DAN) fluorescence method.展开更多
Indium tin oxide (ITO) nanoparticles are synthesized by the two-degradation sulfide and liquid-phase co-precipitation method under the given conditions with solutions of InCl3·4H2O and SnCl4·5H2O in the pres...Indium tin oxide (ITO) nanoparticles are synthesized by the two-degradation sulfide and liquid-phase co-precipitation method under the given conditions with solutions of InCl3·4H2O and SnCl4·5H2O in the presence of ethylendyamine.The sample powders were characterized by x-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses after heat treatments.The SEM results show that the size of the ITO particles prepared by the coprecipitation method is decreased to 100nm,whereas the size of the ITO prepared by degradation of sulfide increases to 1μm after heat treatment.The XRD results reveal that the size of crystallite ITO particles is increased with increasing annealing temperature.Finally the intensity ratio of I400/I222 has an increase of 29.07%for ITO prepared by the co-precipitation method.展开更多
In mineral exploration, the apparent resistivity and apparent frequency （or apparent polarizability） parameters of induced polarization method are commonly utilized to describe the induced polarization anomaly. When...In mineral exploration, the apparent resistivity and apparent frequency （or apparent polarizability） parameters of induced polarization method are commonly utilized to describe the induced polarization anomaly. When the target geology structure is significantly complicated, these parameters would fail to reflect the nature of the anomaly source, and wrong conclusions may be obtained. A wavelet approach and a metal factor method were used to comprehensively interpret the induced polarization anomaly of complex geologic bodies in the Adi Bladia mine. Db5 wavelet basis was used to conduct two-scale decomposition and reconstruction, which effectively suppress the noise interference of greenschist facies regional metamorphism and magma intrusion, making energy concentrated and boundary problem unobservable. On the basis of that, the ore-induced anomaly was effectively extracted by the metal factor method.展开更多
基金financially supported by the State Key Development Program for Basic Research of China (No.2014CB643402)the Collaborative Innovation Center for Clean and Efficient Utilization of Strategic Metal Mineral Resources of Central South University
文摘The flotation of hemimorphite using the S(Ⅱ)–Pb(Ⅱ)–xanthate process,which includes sulfidization with sodium sulfide,activation by lead cations,and subsequent flotation with xanthate,was investigated.The flotation results indicated that hemimorphite floats when the S(Ⅱ)–Pb(Ⅱ)–xanthate process is used; a maximum recovery of approximately 90% was obtained.Zeta-potential,contact-angle,scanning electron microscopy–energy-dispersive spectrometry(SEM–EDS),and diffuse-reflectance infrared Fourier transform spectroscopy(DRIFTS) measurements were used to characterize the activation products on the hemimorphite surface and their subsequent interaction with sodium butyl xanthate(SBX).The results showed that a Zn S coating formed on the hemimorphite surface after the sample was conditioned in an Na2 S solution.However,the formation of a Zn S coating on the hemimorphite surface did not improve hemimorphite flotation.With the subsequent addition of lead cations,Pb S species formed on the mineral surface.The formation of the Pb S species on the surface of hemimorphite significantly increased the adsorption capacity of SBX,forming lead xanthate(referred to as chemical adsorption) and leading to a substantial improvement in hemimorphite flotation.Our results indicate that the addition of lead cations is a critical step in the successful flotation of hemimorphite using the sulfidization–lead ion activation–xanthate process.
基金the Project funded by Ten Thousand Talent Plans for Young Top-notch Talents of Yunnan Province (Grant No. YNWR-QNBJ-2018-051)。
文摘The direct sulfidization of cuprite is inefficient because cuprite is a copper-oxide mineral with a strong surface hydrophilicity.In this study,oxidant was used to modify cuprite surfaces to regulate the sulfidization of cuprite.Microflotation tests showed that the flotation recovery of pre-oxidized cuprite was nearly25% higher than that of direct sulfidization flotation,which indicates that the cuprite surface activity was enhanced after pre-oxidation by Cu(Ⅰ) species(weak affinity with sulfur ions) transformation to Cu(Ⅱ)species(strong affinity with sulfur ions).Zeta potential,scanning electron microscopy-energy dispersive X-ray spectroscopy,X-ray photoelectron spectroscopy,and time-of-flight secondary ion mass spectrometry results showed that pre-oxidation improved cuprite sulfidization and promoted the formation of copper-sulfide species on the cuprite surfaces.The mineral surface stability and thus,xanthate species adsorption on the cuprite surfaces were improved.The surface-adsorption measurements and infrared spectroscopy showed that a large amount of xanthate species was adsorbed onto the sulfidized cuprite surfaces after pre-oxidation,which enhanced the cuprite hydrophobicity and improved the cuprite flotation.
基金the Shanxi Provin-cial Youth Science and Technology Research Fund (No.2008021009-2) for the financial support to this project
文摘The removal of hydrogen sulfide from gas plays an important role in rational utilization of resources and environ- mental protection. In this paper, the process of hydrogen sulfide removal by wet oxidation method in a rotating packed bed was investigated in a scale for treating 10 000 Nm3/h of gas. On the basis of studying the influence of the species and con- centration of alkali source, the liquid/gas volume ratio, the high gravity factor, and the hydrogen sulfide content in feed gas on the desulfurization effect, the suitable technological conditions were obtained. The hydrogen sulfide removal efficiency could reach 98.0% under these conditions. The results of continuous operation of process facilities showed that the high gravity method has many merits including higher desulfurization rate, good stability in operation, lower liquid/gas volume ratio, greater operation elasticity, and apparent energy saving effects.
文摘A flow-based iodometric extraction method for the determination of selenium sulfide was developed and applied to cosmeceutical products. Iodine which was generated from the reduction of selenium（IV） ions by iodide ion was on-line extracted using a polypropylene HFM （hollow fiber membrane） liquid extraction technique. The HFM extraction unit was constructed and used to support an organic solvent （hexane） and separate between the organic phase and aqueous phase. The resulting purple extract was carried to a fiber optic spectrophotometric detector for the measurement at 521 nm. Parameters which affected the extraction efficiency, sensitivity and sample throughput such as iodide （selenium molar ratio, extraction time and washing time between the cycles） were investigated and optimized. A linear dynamic range of 80-373 mg.Lt selenium solution was obtained with an extraction time of 60 sec. The total analysis time including washing was about 180 sec which provided a sample throughput of approximately 20 samples＇hr1 and excluded the sample pre-treatment. The recoveries for the determination of selenium in the forms of selenium dioxide and selenium sulfide were in the range of 103%-104% with 1%-3% RSD （relative standard deviation）. The relative errors of this method which was applied for determination of selenium sulfide levels in an anti-dandruff shampoo and a cosmeceutical bead sample were both less than 2.5%.
文摘A simple and fast ultraviolet spectrophotometric method was used to determineselenium (Ⅳ) through the formation, separaion and quantitative determination of potassium butylxanthae -selenium complex. The complex absorbed light sharply at 375 nm. The optimum acidity ofthe complex formation was between pH 3.4 - 4.0. The absorption value was no change in 120 minutesafter the comlex was extracted by Carbon tetraChioride. The sensitivity of the colour reation was 0.2ng cm-2, The content of selenimp (Ⅳ) was within 0-30 μg and linear rclation was good,Y=0.07X＋0.025, relevent coefficient r＝0.9997. A great quantity of I, Cu, Co, the and SO4-2, PO4-3contained in .the Sample had no effect on the results ofdetenninion when seldsum was determined.When content of Fe was over l00gμg/ml and Zn was over 180μg/ml, there was diotance to the determination, but the disturbance was rem0ved by adding EDTA. When making use of the method todetermine containin seldsum additivef Cv =6.85, rate of recovery was 97.2%, wild jujubef;Cv=3.22,rate of recovery was 90. 1%, soil Samlef Cv=4.64, rate of recovery was 86.2%. The method for sensitivity measured was apprtoate to 2, 3-diamino naphthalene (DAN) fluorescence method.
文摘Indium tin oxide (ITO) nanoparticles are synthesized by the two-degradation sulfide and liquid-phase co-precipitation method under the given conditions with solutions of InCl3·4H2O and SnCl4·5H2O in the presence of ethylendyamine.The sample powders were characterized by x-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses after heat treatments.The SEM results show that the size of the ITO particles prepared by the coprecipitation method is decreased to 100nm,whereas the size of the ITO prepared by degradation of sulfide increases to 1μm after heat treatment.The XRD results reveal that the size of crystallite ITO particles is increased with increasing annealing temperature.Finally the intensity ratio of I400/I222 has an increase of 29.07%for ITO prepared by the co-precipitation method.
基金funded by the National Natural Science Foundation of China(Nos.52174246,51864003)the Open Foundation of Key Laboratory of Green Separation and Enrichment of Strategic Metal Mineral Resources,China(No.202205AG070012)。
基金Project(41174103)supported by the National Natural Science Foundation of ChinaProject(2010-211)supported by the Foreign Mineral Resources Venture Exploration Special Fund of China
文摘In mineral exploration, the apparent resistivity and apparent frequency （or apparent polarizability） parameters of induced polarization method are commonly utilized to describe the induced polarization anomaly. When the target geology structure is significantly complicated, these parameters would fail to reflect the nature of the anomaly source, and wrong conclusions may be obtained. A wavelet approach and a metal factor method were used to comprehensively interpret the induced polarization anomaly of complex geologic bodies in the Adi Bladia mine. Db5 wavelet basis was used to conduct two-scale decomposition and reconstruction, which effectively suppress the noise interference of greenschist facies regional metamorphism and magma intrusion, making energy concentrated and boundary problem unobservable. On the basis of that, the ore-induced anomaly was effectively extracted by the metal factor method.
