文摘
The present work was aimed at studying the bioleachability of aluminium from coarse-grained waste printed circuit boards in a stirred tank reactor. Al recovery, variation of ORP and pH value, during the process of zero-valence Al bioleached by A. ferrooxidans, were discussed in detail. When WPCBs concentrations was 100 g/L, bacterial inoculation was 10% (v/v), temperature was 30 °C, Al extraction rates of WPCBs was up to 82.13% after 30 days. Experimental results indicated that regeneration cyclic process of Fe2+ in bioleaching reactions can accelerate the extraction of Al. Zero-valence aluminium was mainly leached out chemically in the initial stage, and mainly leached out by Fe3+ and H+ in the late stage. The alkaline substance of WPCBs and the oxidation of Fe2+ consume H+, these result in the increasement of pH value in initial stage, whereafter, the decrease of pH value attributes to the hydrolysis of the ferric ion and jarosite precipitation formation.