Kinetics of reaction between CaS and CaSO_4 under N_2 atmosphere
The reaction between CaS and CaSO_4 with different molar ratios in N_2 atmosphere was investigated with a Metteler Toledo thermogravimetric analyzer.In this work, the chemical reaction kinetics and mechanism were discussed in detail.The reaction between CaS and CaSO_4 was the rate-controlling step in the oxidation of CaS to CaO.When CaSO_4 was in excess,the reaction proceeds in two steps.The apparent solid-solid reaction between CaS and CaSO_4 started at 890 ℃ and ended at 1120 ℃.Then the residual CaSO_4 continued decomposing in the range of 1160—1330 ℃.When the molar ratio of CaSO_4 to CaS was 3, the maximal activation energy of 302.46 kJ·mol~(-1) was obtained.The reaction mechanism could be explained by a eutectic liquid model.