中文摘要：

为考察铝土矿生物浸出脱硅的机制,比较了硅酸盐细菌JY03在细菌-矿物接触/非接触模式下与铝土矿的作用,分析浸出过程中铝土矿表面形成的生物膜与钝化膜对溶硅的影响。结果表明,在细菌浸出的前期（0～6d）,铝土矿表面生物膜与钝化膜还未形成,Al与Si的溶出主要受间接接触模式的影响;在6～12d内,铝土矿表面的生物膜逐渐显现,Si的溶出速率明显较非接触模式快,Si的溶出主要受接触模式的影响,12d后,浸出液中SiO2的浓度高于非接触模式17mg/L左右;在8～12d,Al2O3沉淀产生,接触模式下Al的溶出速率明显变缓,非接触模式下明显下降;浸矿12d后,Al2O3絮凝沉淀在铝土矿表面形成钝化膜,浸出液中Al2O3浓度显著下降,SiO2的浓度达到最大值并趋于稳定。因此可以认为,生物膜的形成有利于细菌浸矿溶硅,钝化膜则抑制Al与Si的溶出。

英文摘要：

To study desilication mechanism of bauxite bioleaching, the interaction were compared between the silicate bacterium JY03 and bauxite under the microbe-mineral contact/noncontact modes, and the effects of biofilm and passivation coating forming on the bauxite surface in bioleaching system were investigated. The re- sults show that.in initial step of bioleaching（0-6d）, the bauxite surface were not coated by bio{ilm and passiva- tion coating, and the dissolution approach of A1 and Si was mainly under indirect contact mode; 6-12d, as the biofilm formed gradually on the bauxite surface, the dissolution rate of Si was mainly under contact mode, sig- nificantly higher than indirect contact mode; after a 12d leaching, the concentration of SiO2 in the leaching solu- tion of contact model was about 17mg/L higher than that in the indirect contact mode;; in 8-12d, as Al2O3 sedi- ment was forming, A1 dissolution rate slows significantly in contact system, and decreased in indirect-contact system; after 12d-leaching, when a passive film was formed on the bauxite surface by flocculation and sedimen tation of Al2O3, the A12 03 concentration in the leaching solution was decreased significantly, and SiO2 concen- tration reaches a maximum and stabilized. It is concluded that Si, A1 dissolution can be promoted by biofilm and inhibited by AlcOa passivation coating.