氧化亚锡歧化还原动力学和二氧化锡还原机理

KINETICS OF DISPROPORTIONATION ANDREDUCTION OF STANNOUS OXIDE AND MECHANISMOF REDUCTION OF STANNIC OXIDE

采用差热差重法研究了氧化亚锡分别在氩气流和氢气流中歧化和还原反应动力学。结果表明：在氢气流中氧化亚锡的歧化反应在６７３～１３７３Ｋ的温度范围内与其还原反应相比是优先进行的，而还原反应的速率过程可分别用成核长大和界面反应的非等温动力学模型描述。据此，提出了二氧化锡在不同温度范围内还原的表观机理，例如在６７３～１３７３Ｋ为ＳｎＯ２（ｓ）→还原ＳｎＯ（ｓ）→歧化Ｓｎ（ｌ）。

The kinetics of disproportionation and reduction of stannous oxide in a flow of argon and in a flow of hydrogen has been investigated by TG and DTA techniques. The results showed that in a flow of hydrogen the disproportionation reaction of stannous oxide speeds prior to its reduction in a range of 673～1 373 K, whereas the rate processes of reduction of stannous oxide can be respectively described by the nucleation growth model and the interfacial reaction model of nonisothermal gassolid reactions. Based on the results, the apparent mechanisms of reduction of stannic oxide have been suggested in different temperature ranges, for example, in a range of 673～1 373 K as SnO_2(s)reductionSnO_(s)disproportionationSn(l).