Leaching Characteristics of Trace Elements in Desulfurization Gypsum from a Coal-fired Power Plant

摘要

The contents and leaching characteristics of Cr,Cd,As,Pb and Se in FGD gypsum from a 200MW coalfired power plant were investigated in this study.Experimental results revealed that: the leaching characteristics of As and Se were similar,both leaching rates were not obviously affected by pH but increased with increase of the liquid-solid ratio.Pb and Cr had similar leaching characteristics, their leaching rates were closely related with the pH of leaching solution and increased with the lowering of pH and both increased with the increasing of solid-liquid ratio.Along with the increase of the liquid-solid ratio, the leaching gradually achieved balance,and the balanced liquidsolid ratio was bigger when pH of leaching solution was lower.Cd content of leaching solution was below detect limit,and thus failed to get its leaching characteristics. The order of trace element content in leaching solution is Pb