Stone coal enriches more elements compared to other coals, especially Vanadium (V). The content of Co is relatively low, while its environmental risk is relatively high. This study collected the stone-coal samples to investigate the enrichment characteristics and the chemical speciation in the combustion products of V and Co in stone coal at an open-pit coal mine in Ankang City, Shanxi Province, China. A simulation combustion experiment and sequential chemical extraction were conducted. Mineral composition was analyzed for raw-stone coal and its combustion products. The results showed that most of V and Co are mainly enriched in combustion products during the combustion process, the enrichment capacity of Co is higher than V. With the increase in the combustion temperature, the bioavailable chemical speciation of V in stone coal combustion products increased, while Co decreased. If the combustion products are stored without effective treatment, the surrounding environment will be polluted, and then human health might be endangered.
Keywords: chemical speciation; cobalt; combustion products; enrichment; stone coal; vanadium.