硫酸亜鉛の熱分解速度について
硫酸亜鉛の熱分解に関する研究 (第2報)
1976 年 92 巻 1055 号 p. 33-38
詳細
1976 年 92 巻 1055 号 p. 33-38
The decomposition rate of zinc sulphate in a flow of N2gas was studied by means of thermogravimetric analysis over the temperature range of 670°-830°C, and the rate determining steps of decomposition and the temperature dependence of therate constants are discussed.
The thermal decomposition of zinc sulphate consists of two reaction stages which proceed successively, namely formation of oxysulphate (1st stage) and decomposition of oxysulphate (2nd stage). It is observed that in the 1ststage of decomposition, the decomposition rate is controlled by two processes, namely interface reaction and transport of product gas through the solid product layer. The 2nd stage of decomposition is controlled by interface reaction alone.
Activation energies for the various rate controlling processes in the 1st stage of decomposition have been determined as follows; for the interface reaction 47.7 kcal/mol at temperatures below 740°C and 30.6 kcal/mol above 740°C, and for the transport of product gas 50.6 kcal/mol below 740°C and 34.0 kcal/mol above 740°C. The activation energy for the 2nd stage of decompositionis 58.6 kcal/mol throughout the temperature range investigated.
