粗铅冶炼过程铅元素流分析

Lead Flow Analysis of Lead Bullion Smelting Process

针对粗铅冶炼生产过程中铅金属环境污染问题,应用元素流分析方法,建立了粗铅冶炼过程铅元素流分析框架.以液态高铅渣直接还原工艺为研究对象,通过监测和分析配料、底吹炉、还原炉、烟化炉等工序含铅样品数据及企业台账数据,对生产过程中铅元素流进行全过程识别和追踪分析.结果表明:粗铅冶炼系统铅元素平衡系数为98.61%,铅回收率为98.28%,但铅直收率仅为74.39%,与国内外先进水平相比,还有一定提升空间;单位粗铅产品烟尘、铅尘产生量分别为0.636和0.308 t/t;排放量最大的烟囱是还原炉-烟化炉烟囱,其次为岗位环保烟囱和底吹炉制酸烟囱,三者排放量分别占废气铅排放量的69.06%、25.81%、5.13%.针对粗铅冶炼生产过程中存在的问题,提出了优先提高铅直收率、降低烟尘率、减少无组织粉尘散逸、采用高效脱硫除尘协同防治技术等建议.

An analytical framework of lead elemental flow was established based on substance flow analysis and aimed at solving lead metal pollution during the lead bullion smelting process. The sources and endpoints of lead flow in liquid high-lead slag direct reduction process were researched by monitoring and analyzing both sampled and accounting data of batching system, bottom-blown furnace, reduction furnace and fuming furnace. The results showed that the equilibrium coefficient and recovery ratio of lead bullion smelting system were 98.61% and 98.28% , respectively. However, its direct obtain rate was only 74.39%. Hence, there was more room to improve the process compared with the internationally advanced level. The dust and lead dust generation per unit crude lead were 0. 636 and 0. 308 t/t, respectively. The highest contributing emitter was the chimney of reduction-fuming furnace, followed by the post environmental chimney and the bottom-blown furnace chimney, which accounted for 69.06% , 25.81% and 5.13% of the exhaust emissions of lead, respectively. Several improvements that would provide theoretical references to farther study on reducing lead metal emission were pat forward regarding the existing problems in lead bullion smelting process, including optimizing the lead direct obtain rate, reducing dust yield and the fugitive emission, and applying the cooperative technique integrating desulfurization with dust separation.