Reductive leaching of manganese from electric arc furnace dust in H2SO4

Manganese extraction from electric arc furnace dust was investigated using some reductant agents in sulfuric acid. Three different reductants, glucose, hydrogen peroxide, and oxalic acid were tested. Effect of parameters such as concentration of reductant and sulfuric acid, liquid/solid ratio, leaching temperature as well as reaction time were discussed. A sample of electric arc furnace dust containing about 24% Mn was leached with 0.5, 1, 1.5, 2, 2.5 and 3 M H2SO4 at 25-90 °C for 20-120 min. It was found that Mn recovery was ca. 84% in the presence of oxalic acid as reductant with 0.31 mol/L concentration, liquid/solid ratio of 10/1 at 70°C and 90 min leaching time. Using 0.65 mol/L hydrogen peroxide with liquid/solid ratio of 10/1 at 25°C and 90 min. resulted in almost the same Mn Recovery (86%). Finally, more than 99% Mn recovery was obtained in the presence of 0.31 mol/L oxalic acid at liquid/solid ratio of 30/1, 70°C and 90 min. leaching time.

Keywords:

Electric arc furnace dust , Reductive leaching , Sulfuric acid , Glucose , Hydrogen peroxide , Oxalic acid