煤基直接还原竖炉中熔剂脱硫的热力学和动力学分析

Thermodynamic and Kinetic Study of Desulphuration in Coal Shaft Furnace for Direct Reduction with Flux

在实验室模拟了煤基竖炉直接还原海绵铁的生产过程，并用化学反应热力学、动力学理论和先进的测试手段对熔剂（白云石、石灰石）脱硫进行研究。结果表明，ＭｇＣＯ３在炉内完全分解，但脱硫效果不明显。虽然ＣａＯ脱硫作用较强，但ＣａＣＯ３只有部分分解。因此，竖炉中加入熔剂后对矿石脱硫有一定影响；熔剂脱硫过程的化学反应和内扩散反应的相对阻力随着脱硫反应的进行而变化；减小熔剂粒径是提高熔剂脱硫能力的有效方法。

The shaft furnace process of DRI production has been imitated in the laboratory. Based on the experiment, desulphuration ability of the fluxes has been studied by chemical thermodynamics, chemical kinetics and advanced measuring instruments. The results showed that MgCO 3 is decomposed completely in the shaft furnace but with a small desulphuration ability. CaO is a powerful desulphurizing reagent, but CaCO 3 is decomposed only a little. It is shown that reagent has certain effect on the desulphuration of CaCO 3. The results showed that ralative resistance of chemical reaction and inner diffusion reaction changes along with the desulphurization reaction. Reduction of flux size is a way to increase desulphuration ability.