Penetration analysis of elements and bioleaching treatment of spent refractory for recycling

Acidithiobacillus ferrooxidans ATCC23270 and Acidithiobacillus thiooxidans TM-32 were used for bioleaching of spent refractories of aluminium and copper melting furnaces for their recycling. Firstly, penetration of elements into aluminium melting furnace refractory was investigated and it was found that up to 7 cm from surface was contaminated. Comparison on leaching efficiency by the strains ATCC23270 and TM-32 found that the strain ATCC23270 could treat larger amount of the refractories than the strain TM-32 could do. In the experiment of bioleaching of spent refractory aluminium melting furnace by the strain ATCC23270, high leaching efficiency were obtained on Al, Si, and Ca, and extremely low leaching performance was, however, shown on the rest of elements i.e., Na, Mn, and Zn. Under the strain TM-32 use, relatively high leaching performance was recognized on Al, Si, Ca, Na, Mn, and Zn. In the experiment of bioleaching for spent refractory copper melting furnace, almost the same leaching trends were shown on Cu, Zn, Al, and Si under the strains ACTT23270 and TM-32 uses.