LF热态渣补加石灰再利用的脱硫研究

Research on desulphurization using recycled LF as hot slag with added lime

根据新余钢铁集团公司第二炼钢厂的精炼渣循环利用数据，分析了热态精炼渣补加石灰后脱硫的效果。研究结果表明熔渣碱度为2～3的热态精炼废渣仍具有一定的硫容量，通过补加一定量的石灰可提高其脱硫能力。现场试验表明，向熔渣碱度为2～3的热态精炼渣中补加3～4kg／t的石灰，并加一定量的萤石，脱硫率达到80％以上；并对循环利用的精炼渣进行XRD及EDS物相分析，利用矿相显微镜查看循环利用后的渣的形貌变化，通过分析发现循环利用两次的热态渣岩相种类基本不变，主要为C2S、C3S、C2A、CA，但随着循环次数的增加，钙铝酸盐增多，熔渣混合状况得到改善。热态精炼渣的循环使用的意义不仅在于节约了成本而且降低了对环境污染的危害。

According to the data of slag recycling at the Second Steel-making Plant in XinYu Iron and Steel Group the present article analyzes the effect of desulfurization using the as hot slag with proper addition of lime. The results show that the refining slag with the alkalinity from 2 to 3 still has some sulfur capacity and the as hot slag can increase the desulfurization capacity by supplying a certain amount of lime. Industrial experiments show that by supplying 3;4 kg/t lime to the as hot slag and adding a certain amount of fluorite the desulfurization rate can come up to 80% or more. Phases of the recycled LF hot slag have been analyzed by XRD and EDS and the morphology change of the recycled slag examined by the ore phase microscope as well. Analytical results demonstrate that the slag phase of the as hot slag which has been reused twice basically remains intact and it consists primarily of C2 S.C3 S.C2 A.CA, and the calcium aluminate compounds increases with the increase of the number of recycle and slag mixing condition improves to some extent. The significance of reuse of the as hot slag lies not only at cost reduction, but also lower the hazard of environmental contamination.