Discussed latest research results of basic theory research of coal spontaneous combustion in detail,with quantum chemical theory and method and experiment syste- matically studied chemical structure of coal molecule,a...Discussed latest research results of basic theory research of coal spontaneous combustion in detail,with quantum chemical theory and method and experiment syste- matically studied chemical structure of coal molecule,adsorption mechanism of coal sur- face to oxygen molecule and chemical reaction mechanism and process of spontaneous combustion of organic macromolecule and low molecular weight compound in coal from microcosmic view,and established complete theoretical system of the mechanism of coal spontaneous combustion.展开更多
In this paper, the adsorption-desorption variations of trivalent La, Ce, Y and mixed rare earths are discussed. The curves of pH-rare earth element adsorption were very well fitted to the equation: InD =a+b pH. The se...In this paper, the adsorption-desorption variations of trivalent La, Ce, Y and mixed rare earths are discussed. The curves of pH-rare earth element adsorption were very well fitted to the equation: InD =a+b pH. The selectivity of RE (rare earth element) ions by the samples decreased in the following order: Ce> RE> La> Y, but the sequences were: La> Ce> Y on kaolinite and Y> La on amorphous iron oxide. Since the trivalent RE ions existed in the form of RE(OH)2+ in the solutions from pH < 5.45 to 7.0, the ratio of H+ displaced to RE3+ adsorbed in micromole was proposed to be about 2. The specific adsorption mechanism for RE was proposed to be that the RE ions complexed with oxide surface and the ion-surface complex of Ce3+ promoted oxidization on Mn hydroxide.展开更多
基金National Natural Science Foundation(50474010)Eleventh Five Year Key Technologies(2006BAK03B05)
文摘Discussed latest research results of basic theory research of coal spontaneous combustion in detail,with quantum chemical theory and method and experiment syste- matically studied chemical structure of coal molecule,adsorption mechanism of coal sur- face to oxygen molecule and chemical reaction mechanism and process of spontaneous combustion of organic macromolecule and low molecular weight compound in coal from microcosmic view,and established complete theoretical system of the mechanism of coal spontaneous combustion.
文摘In this paper, the adsorption-desorption variations of trivalent La, Ce, Y and mixed rare earths are discussed. The curves of pH-rare earth element adsorption were very well fitted to the equation: InD =a+b pH. The selectivity of RE (rare earth element) ions by the samples decreased in the following order: Ce> RE> La> Y, but the sequences were: La> Ce> Y on kaolinite and Y> La on amorphous iron oxide. Since the trivalent RE ions existed in the form of RE(OH)2+ in the solutions from pH < 5.45 to 7.0, the ratio of H+ displaced to RE3+ adsorbed in micromole was proposed to be about 2. The specific adsorption mechanism for RE was proposed to be that the RE ions complexed with oxide surface and the ion-surface complex of Ce3+ promoted oxidization on Mn hydroxide.