铜萃取过程对嗜酸氧化亚铁硫杆菌的影响
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摘要
在生物浸出—溶剂萃取—电积提铜技术中,萃取对生物浸出过程必然产生影响.用最大或然数法(most probable number,MPN)研究了主要萃取参数不同时,萃取过程对嗜酸氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans)的影响.结果表明,萃原液pH为1.5~3.0时,萃余液中细菌细胞浓度逐渐增加,其中pH2.0时活细菌所占比例最大,为24.8%;当Lix984N浓度为2.5%~15%时,萃余液中细菌细胞浓度呈现降低趋势,同时活细菌所占比例由23.6%显著降低到6.2%.萃取过程对浸矿细菌有截留作用,将导致返回堆浸环境中浸矿细菌细胞浓度降低,同时使细菌活性减弱,从而使生物浸矿效率下降.
In the process of bioleaching-solvent extraction-electrowinning for copper,the bioleaching process will be inevitably affected by the extraction operation.The effects of copper extraction process on Acidithiobacillus ferrooxidans were studied by utilizing the most probable number(MPN)method under the condition of different main parameters of extraction.The results showed that when aqueous feed was at pH 1.5—3.0,the bacterial cell concentration increased in the raffinate,meanwhile,the proportion of active bacteria in the raffinate accounted for a largest percentage of 24.8% at pH 2.0.While Lix984 N volume concentration was in the range of 2.5%—15%,the bacterial cell concentration decreased in the raffinate,the proportion of active bacteria in raffinate decreased from 23.6% to 6.2%.It was revealed that the extraction process exerted interceptive influence on the leaching bacteria,which would lead to the decrease in the concentration of bacteria cell back to heap leaching environment.Meanwhile,the bacterial activity would be weakened by the extraction process,which would decline the bioleaching efficiency accordingly.
In the process of bioleaching-solvent extraction-electrowinning for copper,the bioleaching process will be inevitably affected by the extraction operation.The effects of copper extraction process on Acidithiobacillus ferrooxidans were studied by utilizing the most probable number(MPN)method under the condition of different main parameters of extraction.The results showed that when aqueous feed was at pH 1.5—3.0,the bacterial cell concentration increased in the raffinate,meanwhile,the proportion of active bacteria in the raffinate accounted for a largest percentage of 24.8% at pH 2.0.While Lix984 N volume concentration was in the range of 2.5%—15%,the bacterial cell concentration decreased in the raffinate,the proportion of active bacteria in raffinate decreased from 23.6% to 6.2%.It was revealed that the extraction process exerted interceptive influence on the leaching bacteria,which would lead to the decrease in the concentration of bacteria cell back to heap leaching environment.Meanwhile,the bacterial activity would be weakened by the extraction process,which would decline the bioleaching efficiency accordingly.
引文
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[4]周桂英,李文娟,陈勃伟,等.微生物活性的影响因素及其对浸矿效率的影响[J].金属矿山,2012(1):80-83.
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[7]邱冠周,刘晓荣,胡岳华.萃取有机相对浸矿细菌的影响[J].中南工业大学学报:自然科学版,2001,32(3):243-246.
[8]Escobar B,Lazo D.Activation of bacteria in agglomerated ores by changing the composition of the leaching solution[J].Hydrometallurgy,2003,71(1):173-178.
[9]Hawkes R B,Franzmann P D,Plumb J J.Moderate thermophiles including“Ferroplasma cupricumulans”sp.nov.dominate an industrial-scale chalcocite heap bioleaching operation[J].Hydrometallurgy,2006,83(1/4):229-236.
[10]Knickerbocker C,Nordstromand D K,Southam G.The role of“blebbing”in overcoming the hydrophobic barrier during biooxidation of elemental sulfur by Thiobacillus thiooxidans[J].Chemical Geology,2000,169(3):425-433.
[11]Escobar B,Godoy I.Determination of sulfur and iron oxidation bacteria by the most probable number(MPN)technique[J].Process Metallurgy,1999,9:681-687.
[12]Sutton S.The most probable number method and its uses in enumeration,qualification,and validation[J].Journal of Validation Technology,2010,16(3):35-38.
[13]GB 4789.3—2010食品安全国家标准食品微生物学检验大肠菌群计数[S].北京:中国标准出版社,2010.
[14]刘晓荣.铜溶剂萃取界面乳化机理及防治研究[D].长沙:中南大学,2001.
[2]Rotuska K,Chmielewski T.Growing role of solvent extraction in copper ores processing[J].Physicochemical Problems of Mineral Processing,2008,42:29-36.
[3]Watling H R,Perrot F A,Shiers D W,et al.Impact of the copper solvent extraction reagent Lix984Non the growth and activity of selected acidophiles[J].Hydrometallurgy,2009,95(3):302-307.
[4]周桂英,李文娟,陈勃伟,等.微生物活性的影响因素及其对浸矿效率的影响[J].金属矿山,2012(1):80-83.
[5]Okibe N,Johnson D B.Toxicity of flotation reagents to moderately thermophilic bioleaching microorganisms[J].Biotechnology Letters,2002,24(23):2011-2016.
[6]Davis B C S,Gallardo I,Demergasso C.Effect of organic extractant Lix84IC,pH and temperature changes on bioleaching microorganisms during SX treatment[J].Hydrometallurgy,2012,129-130(12):135-139.
[7]邱冠周,刘晓荣,胡岳华.萃取有机相对浸矿细菌的影响[J].中南工业大学学报:自然科学版,2001,32(3):243-246.
[8]Escobar B,Lazo D.Activation of bacteria in agglomerated ores by changing the composition of the leaching solution[J].Hydrometallurgy,2003,71(1):173-178.
[9]Hawkes R B,Franzmann P D,Plumb J J.Moderate thermophiles including“Ferroplasma cupricumulans”sp.nov.dominate an industrial-scale chalcocite heap bioleaching operation[J].Hydrometallurgy,2006,83(1/4):229-236.
[10]Knickerbocker C,Nordstromand D K,Southam G.The role of“blebbing”in overcoming the hydrophobic barrier during biooxidation of elemental sulfur by Thiobacillus thiooxidans[J].Chemical Geology,2000,169(3):425-433.
[11]Escobar B,Godoy I.Determination of sulfur and iron oxidation bacteria by the most probable number(MPN)technique[J].Process Metallurgy,1999,9:681-687.
[12]Sutton S.The most probable number method and its uses in enumeration,qualification,and validation[J].Journal of Validation Technology,2010,16(3):35-38.
[13]GB 4789.3—2010食品安全国家标准食品微生物学检验大肠菌群计数[S].北京:中国标准出版社,2010.
[14]刘晓荣.铜溶剂萃取界面乳化机理及防治研究[D].长沙:中南大学,2001.