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嗜热细菌生物浸出黄铜矿的铜浸出率,取决于温度、pH和氧化还原电位,而且还取决于所使用的嗜热细菌的活性。研究了在不同的pH值和温度并有着不同的初始Fe3+数量的条件下,使用三种嗜热细菌浸出时达到的铜浸出率。获得的结果表明,由于Acidianus brierleyi(缩写为A.brierleyi菌)浸出铁(以Fe3+形式)的能力很低,由接近临界值(450mV,Ag°/AgCl参比电极)的氧化还原电位,反映出达到了很高的生物量浓度,在这样的氧化还原电位下浸出时铜浸出率最高。相比之下,由于Sulfolobus metallicus(S.metallicus菌)和Metallosphaerasedula(缩写为M.sedula菌)较高的浸出铁(以Fe3+形式)的能力,由很高的氧化还原电位反映出的很高的生物量浓度,再结合Fe3+以黄钾铁矾(KFe3[SO4]2.(OH)b)形式的沉淀作用,因而就降低了浸出速率。因此,在对于嗜热细菌的生长是最佳的温度时,并不总是意味着能达到很高的铜浸出率。一般地说,最高的铜浸出率是在初始pH值为1.5的条件下达到的。然而,在初始pH值为2.5时观测到比在pH2.0时达到了更高的浸出率,证实了在高pH值时黄铜矿的生物浸出是受氧化还原电位而不是由pH或温度所控制的。当提供的为激发浸出反应所需的初始的Fe3+数量不足时,双向酸杆菌的生物浸出能力就会降氏,或浸出反应受到抑制,而硫化裂片菌和金属丝菌对初始的Fe3+提供量就没有那么敏感。这一结果证实了对矿物表面直接的酶促催化作用,能引发黄铜矿的生物浸出反应,但稍后氧化还原电位就控制着黄铜矿的浸出速率。
The leaching rate of copper from thermophilic bacterium bioleaching chalcopyrite is dependent on temperature, pH and redox potential, but also on the activity of the thermophilic bacteria used. Copper leaching rates achieved with three thermophilic bacteria leaching were studied at different pH values and temperatures with different initial Fe3 + numbers. The results obtained show that since the ability of Acidianus brierleyi (abbreviated as A.brierleyi) to leach iron (in the form of Fe3 +) is very low, the redox potential near the critical value (450mV, Ag / AgCl reference electrode) A very high biomass concentration is reached, with the highest rate of copper leaching at this redox potential. In contrast, due to the higher ability of Sulfolobus metallicus (S. metallalusus) and Metallosphaerasedula (abbreviated M.sedula) to leach iron (in the form of Fe3 +), the high redox potential reflects Biomass concentration, combined with the precipitation of Fe3 + in the form of jarosite (KFe3 [SO4] 2. (OH) b), reduced the leaching rate. Therefore, at temperatures that are optimal for the growth of thermophilic bacteria, it does not always mean that a high copper leach rate can be achieved. In general, the highest copper leaching rate is achieved at an initial pH of 1.5. However, a higher leaching rate was observed at an initial pH of 2.5 than at pH 2.0, confirming that the bioleaching of chalcopyrite at high pH is affected by the redox potential rather than by pH or temperature controlling. When the initial amount of Fe3 + required for provoking the leaching reaction is insufficient, the bioleaching capacity of C. acidicola decreases, or the leaching reaction is inhibited, and the amount of initial supply of Fe3 + Not so sensitive. This result confirms the direct enzymatic catalysis of the mineral surface, which can initiate the bioleaching reaction of chalcopyrite, but later the redox potential controls the chalcopyrite leaching rate.