Study On Degradability Effects Of Carbon In Gold Ores Using Phanerochaete Chrysosporium

The carbonaceous gold ores is refractory due to that it contains carbonaceous substance, especially organic carbon. During the cyanide leaching process of gold ore, the carbon can adsorp the gold have been leached and reduce the recovery rate of gold. As the gold resources are increasingly poor and environmental requirements are continuously strict, how to use carbonaceous gold ores economically and efficiently has become a serious problem to be solved. This paper mainly studies the biotransformation process of carbonaceous gold. Phanerochaete chrysosporium was chosen to pretreat the refractory gold ores.The biological characteristics and cultivated conditions of Phanerochaete chrysosporium JT-AU had been investigated firstly. The results showed that Phanerochaete chrysosporium JT-AU grows fast at 35?,150 r·min-1, pH 5.0, the log phase was 1?7d and 7?25 d for stable phase, long stable period provided a stable substrate for degradation. During the process of growth, pH of the solution was decreased firstly and increased subsequently. The orthogonal experimental design were conducted using the size of carbon materials, the fungus liquid, the concentration of slurry and the degradation time as variables. And the degradations rate of carbonaceous materials, such as graphite, activated carbon and humic acid, were investigated, Phanerochaete chrysosporium JT-AU have different degradabilities for the three carbon materials,13.49%,22.44% and 33.74% respectively, and the larger one is for humic acid. The size of carbon materials and the degradation time influence more seriously on the biodegradation effect than the fungus liquid and the concentration of slurry. The products of bioconversion process were analyzed by FTIR. The results showed that a large amount of carboxylic acids, phenols, alcohols and other acidic functional groups was produced. And the carbonaceous substances were oxidized in some degree due to the increase of oxygenic and aromatic groups. After the degradation process of Phanerochaete chrysosporium JT-AU, the adsorption rate of the activated carbon, graphite and humic acid decreased by 48.62%,8.82% and 11.11% respectively.The pretreatments of carbonaceous gold ore using Phanerochaete chrysosporium JT-AU were also studied systematically. The best degradation rate was get at the size of carbon materials in 38?47\im, the fungus liquid 6%, the concentration of slurry 1% and the degradation time was 14d. After the function of Phanerochaete chrysosporium JT-AU, the content of arsenic, carbon and iron were also reduced, removal rate was and 29.35%,9.12% and 51.64% respectively, and the weightlessness rate of ores was 27%. The gold concentration increased to 130% of gold in raw ores, XRD revealed the carbonate in the ore was almost broken down completely. The slag adsorption rate of gold ores was reduced by 62.5% after the pretreatment process of Phanerochaete chrysosporium JT-AU, the pretreatment effect of the gold ores is efficient. The above results certified that Phanerochaete chrysosporium JT-AU could be a new valuable strain for the carbon and arsenic removal.