烟化处理针铁矿渣的热力学分析

Thermodynamic analysis of fuming process for treating goethite residues

为了了解针铁矿渣的化学组成及微观结构,并针对该物料特点进行热力学分析,对针铁矿渣进行化学分析、物相分析、形貌分析及热重分析.结果表明,针铁矿渣中铁、铅、锌等主要以硫酸盐形式存在,烟化处理时,硫酸盐高温分解呈氧化物形态,在还原剂的作用下还原成金属单质.合理控制还原气氛可实现铅、锌氧化物的最大程度的还原,金属蒸气在炉膛上部遇空气重新氧化,进入烟气系统回收,配入适当的熔剂造渣,可以得到稳定、无害的玻璃体.

To learn about the chemical composition and microstructure of goethite residue and analyze its thermodynamic characteristics, the residue was studied by chemical analysis, phase analysis, morphology observation and thermogravimetric analysis. The results show that： Iron, lead, zinc and other elements mainly exist in the form of sulfate in goethite residue. In the fuming process, the sulfate decompose into oxides and then reduce into metals under the action of reducing agent. PbO and ZnO could be maximally reduced if the reducing atmosphere is reasonably controlled. The metal vapor is oxidized by air again in the upper chamber of the fuming furnace and received from the flue-gas recycling system, slagging. Stable and harmless vitreous slags could be eventually obtained when some appropriate fluxes were added.