中国有色金属学报
中國有色金屬學報
중국유색금속학보
THE CHINESE JOURNAL OF NONFERROUS METALS
2014年
4期
1099-1109
,共11页
富钾页岩%钾细菌%生物膜%表面钝化%生物浸出机制
富鉀頁巖%鉀細菌%生物膜%錶麵鈍化%生物浸齣機製
부갑혈암%갑세균%생물막%표면둔화%생물침출궤제
potassium-rich shale%potassium-solubilizing bacteria%biofilm%surface passivation%bioleaching mechanism
在细菌-矿物接触模式和用微孔滤膜将细菌和矿物隔离的非接触模式下,研究钾细菌(CGMCC1.2411)对富钾页岩浸出分解的影响,并对浸出过程中富钾页岩表面生物膜和钝化膜的形成原因及其对 K、Si和Al的溶出影响进行分析。结果表明:与非接触模式相比,细菌-矿物接触模式下钾细菌的对数生长期延长了2 d,且具有较高的产酸、产蛋白质和多糖的能力。比较细菌-矿物接触模式和细菌-矿物非接触模式可知,细菌-矿物接触模式更有利于促进富钾页岩的浸出,但对K、Si和Al的溶出贡献存在一定的差别。在浸出的0~6 d内,K、Al的溶出主要受间接作用的影响;在浸出的6~15 d内,主要受直接作用的影响;在整个浸出周期内,Si的溶出主要受间接作用的影响。在细菌-矿物接触模式下,矿物表面形成的生物膜对富钾页岩的溶蚀及K、Si和Al的溶出具有促进作用;细菌代谢产物对Al的溶出具有抑制作用,溶出的Al易于在细菌代谢产生的胞外多糖絮凝作用下生成水合铝石,有机酸铝沉淀是导致富钾页岩表面钝化和抑制富钾页岩进一步溶解的原因之一。
在細菌-礦物接觸模式和用微孔濾膜將細菌和礦物隔離的非接觸模式下,研究鉀細菌(CGMCC1.2411)對富鉀頁巖浸齣分解的影響,併對浸齣過程中富鉀頁巖錶麵生物膜和鈍化膜的形成原因及其對 K、Si和Al的溶齣影響進行分析。結果錶明:與非接觸模式相比,細菌-礦物接觸模式下鉀細菌的對數生長期延長瞭2 d,且具有較高的產痠、產蛋白質和多糖的能力。比較細菌-礦物接觸模式和細菌-礦物非接觸模式可知,細菌-礦物接觸模式更有利于促進富鉀頁巖的浸齣,但對K、Si和Al的溶齣貢獻存在一定的差彆。在浸齣的0~6 d內,K、Al的溶齣主要受間接作用的影響;在浸齣的6~15 d內,主要受直接作用的影響;在整箇浸齣週期內,Si的溶齣主要受間接作用的影響。在細菌-礦物接觸模式下,礦物錶麵形成的生物膜對富鉀頁巖的溶蝕及K、Si和Al的溶齣具有促進作用;細菌代謝產物對Al的溶齣具有抑製作用,溶齣的Al易于在細菌代謝產生的胞外多糖絮凝作用下生成水閤鋁石,有機痠鋁沉澱是導緻富鉀頁巖錶麵鈍化和抑製富鉀頁巖進一步溶解的原因之一。
재세균-광물접촉모식화용미공려막장세균화광물격리적비접촉모식하,연구갑세균(CGMCC1.2411)대부갑혈암침출분해적영향,병대침출과정중부갑혈암표면생물막화둔화막적형성원인급기대 K、Si화Al적용출영향진행분석。결과표명:여비접촉모식상비,세균-광물접촉모식하갑세균적대수생장기연장료2 d,차구유교고적산산、산단백질화다당적능력。비교세균-광물접촉모식화세균-광물비접촉모식가지,세균-광물접촉모식경유리우촉진부갑혈암적침출,단대K、Si화Al적용출공헌존재일정적차별。재침출적0~6 d내,K、Al적용출주요수간접작용적영향;재침출적6~15 d내,주요수직접작용적영향;재정개침출주기내,Si적용출주요수간접작용적영향。재세균-광물접촉모식하,광물표면형성적생물막대부갑혈암적용식급K、Si화Al적용출구유촉진작용;세균대사산물대Al적용출구유억제작용,용출적Al역우재세균대사산생적포외다당서응작용하생성수합려석,유궤산려침정시도치부갑혈암표면둔화화억제부갑혈암진일보용해적원인지일。
The microbial decomposition of potassium-bearing silicate minerals includes the direct mechanism and the indirect mechanism, but the contribution of each mechanism to the mineral weathering is still in controversy. The effect of potassium-solubilizing bacteria on decomposition of potassium-rich shale in the bacteria-mineral contact/uncontact model was studied by employing microfiltration membrane to segregate mineral powders from bacteria, and the selective analysis of mineral surface biofilm and passivation and their effects on release of K, Si and Al were also investigated. The results show that the potassium-solubilizing bacterium grows in the exponential phase for more than two days, and has higher ability of producing acids, proteins and polysaccharides in the bacteria-mineral contact model, comparing with the bacteria-mineral uncontact model. The bacteria-mineral contact model is more profitable for leaching of potassium-rich shale than the uncontact model, but its relative contribution to the release of different elements of K, Si and Al is different. The release of K and Al is controlled mainly by the indirect mechanism during bioleaching process in 0-6 d, and mainly by the direct mechanism in 6-15 d. However, the release of Si is determined mainly by the indirect mechanism in the whole bioleaching process. The biofilm formation on mineral surface can promote the corrosion of potassium-rich shaleand the release of K, Si and Al in the bacteria-mineral contact model. The bacterial metabolites have an inhibiting effect on the release of Al, and have an effective flocculation effect on Al. The precipitates of diaspore and organic acid aluminum are one of the primer causes of surface passivation of potassium-rich shale, and the surface passivation has obviously inhibition effect on the dissolution of potassium-rich shale.