Various incorporation of Au in pyrite and its effects on the geometrical structure,electronic structure and flotability of pyrite were theoretically investigated and fully discussed by performing density functional th...Various incorporation of Au in pyrite and its effects on the geometrical structure,electronic structure and flotability of pyrite were theoretically investigated and fully discussed by performing density functional theory(DFT).The calculated incorporation energy shows that gold would most likely exist in pyrite via incorporating into interstitial lattice sites in the absence of As impurity.As a result of incorporated Au,the covalence levels of the S—Fe and S—S bonds are changed,and the tonicity of Au—S bonds and antibonding of Au—Fe bonds are found to form in the pyrite,which would change the natural flotability of pyrite.The Au impurity energy levels are introduced into the energy band and result in the transformation of pyrite semiconductivity type.The calculated band-gap value suggests that the incorporated Au significantly decreases pyrite semiconductivity level,which enhances the formation and the adsorption stability of dixanthogen during pyrite flotation.The DOS results reveal that the stability and depression difficulty level of pyrites increases in the following order:Fe_(32)S_(63)As<Fe_(32)S_(64)<Fe_(32)S_(63)As Au<Fe_(32)S_(64)Au.展开更多
16 samples of Chinese coal were tested for their flotation and hydropbilic properties. The two physico-chemical parameters, wetting heat and contact angle were compared as they were used in evaluating the flotability ...16 samples of Chinese coal were tested for their flotation and hydropbilic properties. The two physico-chemical parameters, wetting heat and contact angle were compared as they were used in evaluating the flotability of coal. The result shows that the wetting heat is in good accordance with flotability and is better than contact angle in reflecting the flotability. A new idea of classifying the flotability using wetting heat is put forward.展开更多
为拓宽电化学法在煤脱硫中的应用及提高煤的可浮性,研究了金属腐蚀电偶法的各因素对脱硫效果的影响和对高硫煤的浮选脱硫机理.利用红外光谱和X射线衍射对金属腐蚀电偶法处理前后的煤样进行了分析.结果表明:各因素的影响次序从大到小为...为拓宽电化学法在煤脱硫中的应用及提高煤的可浮性,研究了金属腐蚀电偶法的各因素对脱硫效果的影响和对高硫煤的浮选脱硫机理.利用红外光谱和X射线衍射对金属腐蚀电偶法处理前后的煤样进行了分析.结果表明:各因素的影响次序从大到小为反应时间、反应温度、金属用量、pH.确定了最佳反应条件,反应时间为30 m in,反应温度为40℃,金属用量为理论用量的2倍,pH为5.脱硫率可达到61.39%;而且还能脱出部分有机硫.金属腐蚀电偶法脱硫是一种高效、安全、温和的脱硫方法,它能使煤与黄铁矿颗粒表面朝不同的方向改性,提高煤的可浮性,降低黄铁矿的可浮性.展开更多
基金Projects(51504109,51504107)supported by the National Natural Science Foundation of China
文摘Various incorporation of Au in pyrite and its effects on the geometrical structure,electronic structure and flotability of pyrite were theoretically investigated and fully discussed by performing density functional theory(DFT).The calculated incorporation energy shows that gold would most likely exist in pyrite via incorporating into interstitial lattice sites in the absence of As impurity.As a result of incorporated Au,the covalence levels of the S—Fe and S—S bonds are changed,and the tonicity of Au—S bonds and antibonding of Au—Fe bonds are found to form in the pyrite,which would change the natural flotability of pyrite.The Au impurity energy levels are introduced into the energy band and result in the transformation of pyrite semiconductivity type.The calculated band-gap value suggests that the incorporated Au significantly decreases pyrite semiconductivity level,which enhances the formation and the adsorption stability of dixanthogen during pyrite flotation.The DOS results reveal that the stability and depression difficulty level of pyrites increases in the following order:Fe_(32)S_(63)As<Fe_(32)S_(64)<Fe_(32)S_(63)As Au<Fe_(32)S_(64)Au.
文摘16 samples of Chinese coal were tested for their flotation and hydropbilic properties. The two physico-chemical parameters, wetting heat and contact angle were compared as they were used in evaluating the flotability of coal. The result shows that the wetting heat is in good accordance with flotability and is better than contact angle in reflecting the flotability. A new idea of classifying the flotability using wetting heat is put forward.
文摘为拓宽电化学法在煤脱硫中的应用及提高煤的可浮性,研究了金属腐蚀电偶法的各因素对脱硫效果的影响和对高硫煤的浮选脱硫机理.利用红外光谱和X射线衍射对金属腐蚀电偶法处理前后的煤样进行了分析.结果表明:各因素的影响次序从大到小为反应时间、反应温度、金属用量、pH.确定了最佳反应条件,反应时间为30 m in,反应温度为40℃,金属用量为理论用量的2倍,pH为5.脱硫率可达到61.39%;而且还能脱出部分有机硫.金属腐蚀电偶法脱硫是一种高效、安全、温和的脱硫方法,它能使煤与黄铁矿颗粒表面朝不同的方向改性,提高煤的可浮性,降低黄铁矿的可浮性.
