KR脱硫渣的综合利用现状及其氧化去硫研究进展

Present situation of comprehensive utilization of KR desulfurization slag and research progress of CaS oxidation

KR脱硫的渣资源化利用有利于促进钢铁企业的绿色化发展。KR脱硫渣中主要成分为CaO,且含有质量分数为1.0%~2.5%的硫,直接将KR脱硫渣回用于冶炼工艺会导致钢液增硫。若能将渣中的硫脱出,可有效促进KR脱硫渣在钢铁冶炼工艺的资源化利用。因此,针对当前KR脱硫渣综合利用存在的问题,总结分析有关CaS氧化过程的热力学和动力学研究现状,探究将KR脱硫渣中硫转化成为SO_(2)的有利条件,分析将KR脱硫渣用于转炉造渣脱磷的可行性,以实现KR脱硫渣的冶金内循环利用。KR脱硫渣中的硫主要以CaS形式赋存在渣中,高温(温度T>1 373 K)、低氧分压(P_(O2)<10.1 kPa)条件下有利于CaS氧化为SO_(2)。在气-固反应过程中,反应初期KR脱硫渣中硫的氧化过程受化学反应控制,反应后期受O_(2)的内扩散控制;在气-液反应过程中,反应受S^(2-)的扩散控制。

The resource utilization of KR desulfurization slag is beneficial to the green development of iron and steel enterprises.The main component of KR desulfurization slag is CaO and sulfur with mass fraction of 1.0%-2.5%.Directly reusing KR desulfurized slag for smelting process will lead to sulfur increase in liquid steel.If the sulfur in the slag can be removed,it can effectively promote the resource utilization of KR desulfurization slag in iron and steel smelting process.Therefore,in view of the current problems in the comprehensive utilization of KR desulfurization slag,the current research status of the thermodynamics and kinetics of the CaS oxidation process was summarized and analyzed,the favorable conditions of converting the sulfur of KR desulfurization slag into SO_(2) was explored,and the feasibility of using KR desulfurized slag in converter slag making and dephosphorization was analyzed to realize the metallurgical internal recycling of KR desulfurization slag.The sulfur in KR desulfurization slag is mainly contained in the slag in the form of CaS.High temperature(T>1 373 K) and low oxygen partial pressure(P_(O2)<10.1 kPa) are beneficial to the oxidation of CaS to SO_(2).In the gas-solid reaction process,the oxidation process of the KR desulfurization slag in the initial stage of the reaction is controlled by a chemical reaction and the diffusion of O_(2) through the porous layer of the reaction products at the later stage of reaction;In the gas-liquid reaction process,the reaction is mainly controlled by the diffusion of S^(2-).