为了探讨耐锰菌Fusarium sp.浸出锰离子的作用机制,对比分析了用Fusarium sp.与外加有机酸浸取后电解锰废渣的表征及锰离子浸出率的变化,重点考察了在Fusarium sp.浸取条件下锰离子浸出率、pH以及部分有机酸含量变化的关系.在锰离子的浸出过程中,当加入Fusarium sp.后,浸取后的电解锰废渣表现出更为疏松多孔的物理特质,且在47 h内锰离子浸出率上升至84%,比单独加入不同有机酸浸取130 h后的最高浸出率高2.30倍;锰离子浸取率和有机酸含量呈先增后降、pH呈先降后增的变化趋势.同时,含量最多的琥珀酸和L-苹果酸分别在浸出57 h和62 h后升至最高,分别为11.12 g/L和10.23 g/L,pH在29 h后降至最低(4.09).结果表明,Fusarium sp.及其代谢产生的有机酸在锰离子的浸出过程中起重要的作用,利用Fusarium sp.浸出锰渣中锰离子具有效果好,周期短等优点.但因电解锰废渣致密紧实的物理特质,以及浸出体系中有机酸的产出与消耗、吸附与络合作用同时存在,锰离子浸出率与pH值、有机酸含量的变化不成单一的线性关系,且在浸出后期锰离子浸出率下降趋势明显.
The manganse bioleaching mechanism by a manganese-resistant strain Fusarium sp.was investigated,through analyzing the bioleaching rate and manganese-electrolytic residue characterizations with the presence of Fusarium sp.and with the addition of organic acids.Special attention was paid to explore the relationship among the manganese's leaching rate,pH,and organic acid concentration during Fusarium sp.bioleaching process.The research results showed that,with the addition of Fusarium sp.,some looser and more porous manganese-electrolytic residues could be obtained.And after 47 hours,the leaching rate reached to 84% which was 2.30 times higher than that leached by individual organic acid even after 130 hours;the leaching rate of manganese and the concentrations of organic acids increased at the initial stage and then decreased,while pH was the reversed.Additionally,the concentration of Succinic acid and L-Malic acid reached their crest value(11.12 g/L and 10.23 g/L) at 57 and 62 hours respectively.Yet the pH reached the lowest(4.09) at 29 h,which implied that,Fusarium sp.and organic acid produced played an important role in the leaching of manganese,leading to a high-efficiency and time-saving process.However,due to the high density of manganese-electrolytic residue and the concurrence of the produce and consumption of organic acid together with the adsorption and complexation,the relationship among the extraction rate for manganese ion,pH,and the concentration of organic acid produced could not be described by simple linear correlation and the leaching rate decreased significantly in the later stage.