Fundamental Studies on the Collection of Sulphide Minerals with Xanthic Acids. I : On the Dissociation and Decomposition of Xanthic Aicds

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概要

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• The dissociation constants of xanthic acids and the rates of decomposition of xanthic ions in acidified aqueous solutions were determined by spectrophotometric measurements. It was found that xanthic ion and xanthic acid are virtually in equilibrium, and that the dissociation constants of methyl-, ethyl, propyl-, butyl-, amyl-, iso-propyl-, and iso-butylxanthic acids are respectively 3.4×10^<-2>, 2.9×10^<-2>, 2.5×10^<-2>, 2.3×10^<-2>, 1.9×10^<-2>, 2.0×10^<-2> and 1.4×10^<-2> at 25℃ and the ionic strength of 0. The instability of xanthic ion in acidic range is due to the bimoleucular decomposition of xanthic ion and hydrogen ion. The rate constants of decomposition of methyl-, ethyl-, propyl-, amyl-, isopropyl-, and iso-butylxanthic ions are respectively 233, 226, 214, 209, 211. 207, and 202 mole^<-1>min^<-1> at 25℃ and the ionic strength of 0. The dissociation constants of these xanthic acids and the rate constants of these xanthic ions decreased the increase in carbon numbers of these alkyl groups, and iso-isomer has smaller values of these constants than those of normal ones. Furthermore, it was shown that the peak of absorption spectrum of xanthic ion is at 301 mμ and that of xanthic acid at 270 mμ.

• 東北大学の論文

著者

• Majima Hiroshi

  The Research Institute Of Mineral Dressing And Metallurgy

関連論文

• Fundamental Studies on the Collection of Sulphide Minerals with Xanthic Acids. I : On the Dissociation and Decomposition of Xanthic Aicds
• Studies on the Flotation of Molybdenite. II : Some Experiments on the Kerosene Flotation
• Fundamental Studies on the Collection of Sulphide Minerals with Xanthic Acids. II : Reactions of Formation of Heavy Metal Complexes with Xanthic Acids
• Studies on the Flotation of Molybdenite. I : Flotation of Molybdenite Ore Containing Clayey Gangue

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