Acta Montanistica Slovaca (Mar 2010)
Non-isothermal microwave leaching kinetics of zinc removal from basic oxygen furnace dust
Abstract
The basic oxygen furnace (BOF) dust is a hazardous metallurgical waste generated in the collection of particulate material duringsteel making processes. The occurrence and recovery of metallurgical wastes from steelmaking and iron making processes becomenowadays a great problem, mainly due to the big amount and environmental pollution by heavy metals potential. The research of nonisothermalkinetics by microwave heating was evaluated. Experimental results indicate that the most important factor that strongly affectedmicrowave acid extraction was the microwave power input. It is shown that approximately from 22 to 50°C the process is controlled bydiffusion with a low apparent activation energy value of Ea = 1.15 kJ/mol. With increasing temperature the Arrhenius slope is more steeperwith the apparent activation energy value of Ea = 22.01 kJ/mol, which proves that the microwave leaching process from 50°C is undercontrol by the surface chemical reaction. This indicates that the microwave promotes the mineral solid particle to burst effectively, makes theparticle to expose a fresh surface and strengthens the leaching process.
