著者

江口 元徳 矢沢 彬

出版者

一般社団法人 資源・素材学会

雑誌

日本鉱業会誌 (ISSN:03694194)

巻号頁・発行日

vol.91, no.1043, pp.39-44, 1975-01-25 (Released:2011-07-13)

参考文献数

24

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Hydrolysis reaction in Co (II)-H2O system have been investigated thermodynamically and experimentally, at temperaturesbetween 25°and 200°C. The results are summerized as follows:(1) The chemical potentials of relating substances at 25°to 250°C were derived by several thermodynamic ways.(2) The hydrolysis equilibrium was discussed thermodynamically, and it was predicted that CoOH+would not be predominantunder the conditions considered.(3) The pH dependences of solubility of Co (OH) 2were measured at temperatures between 25°and 200°C. pH values were measured directly at equilibrating temperatures below 100°C, but were measuredat 25°C for quenched solutions in the experiments above 100°C.(4) Correspondence of pH values between 25°and t°C based on eq.(23) in this paper was confirmed by experiment.(5) Red Co (OH) 2were precipitated in the experiments at above 90°C and thermodynamic behavior agreed well with the theoretical predicitions (Fig. 10).(6) A bluish active Co (OH) 2was precipitated at 25°C as a metaslable form, and for this active hydroxide Ksp=7.8·10-15, μ°298=-107.7 kcal/mol were derived