黔西南某中高硫煤脱硫过程中微量元素的分配特性研究

为探究黔西南某中高硫煤中微量元素的富集程度,以及在脱硫降灰提质利用过程中微量元素的分配特性,通过摇床对其脱硫降灰进行了试验研究,并在合适的分选工艺条件下,考察了原煤、精煤和尾煤产品中微量元素的分配特征。通过“一粗一精一扫”重选,可获得产率32.83%、硫分0.96%、灰分11.16%的合格精煤产品。分选产品微量元素分析结果表明,该分选工艺对Cu、Sb、As、Co、Mo、TI、Ni等有害元素具有较好的脱除效果,并能一定程度富集锂和稀土等有价微量元素。通过此工艺可分别回收28.73%和47.37%的锂至精煤和中煤产品,精煤煤灰中Li₂O理论含量达5 258 μg/g,具有综合回收利用价值。研究结果可为该类中高硫煤炭资源的清洁与综合利用提供参考。

Distribution of Trace Elements amid Desulfurization of Medium-High Sulfur Coal in Southwestern Guizhou

The enrichment degree of trace elements in a medium-high sulfur coal in southwestern Guizhou Province and their distribution characteristics during desulfurization and deashing processes were explored. A shaking table separation process was adopted to evaluate the desulfurization and deashing efficiencies. Meanwhile, the distribution characteristics of trace elements in the raw coal, the cleaned coal and the tailings were investigated based on the feasible separation parameters. After a gravity separation consisting of one roughing, one cleaning and one scavenging, a cleaned coal can be prepared at a yield of 32.83% and is regarded as the qualified product as its sulfur and ash content reduced to 0.96% and 11.16%, respectively. It can be concluded from an analysis on trace elements of the products that adopting this technology, the harmful elements such as Cu, Sb, As, Co, Mo, Ti and Ni can be effectively removed, while valuable trace elements such as Li and rare earth can be enriched to a certain extent. It is shown that this processing technique can result in 28.73% and 47.37% Li recovery into the cleaned coal and middlings respectively, and the theoretical content of Li₂O in the ash of the cleaned coal reaches 5 258 μg/g, indicating it′s valuable for comprehensive recovery and utilization. This study can provide reference for cleaning and comprehensive utilization of medium-high sulfur coal resources.