次生硫化铜矿微生物浸出实验
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摘要
微生物浸矿是提取低品位,难选次生硫化铜矿中有价元素的最有效方法之一.本研究利用嗜酸氧化亚铁硫杆菌(Acidthiobacillus ferrooxidans)浸取福建某难选次生硫化铜矿,依次开展浸矿菌富集培养实验、驯化转代实验和不同粒径配比下柱浸试验,获得了不同阶段的细菌浓度、pH值、铜浸出率等演变规律;并结合电子计算机断层扫描技术实现了柱内矿堆塌落、截面孔隙演化和浸矿机理研究.研究表明:细菌浓度和pH值均呈现缓慢增加后趋降低的趋势,浸柱中细菌增殖较慢,浸矿480 h后,细菌浓度仅为每毫升5×107个.浸矿过程中,细颗粒趋于向柱底迁移,矿堆出现塌落;柱顶孔隙率变大,增幅为6.65%,柱底孔隙率变小,降幅为8.29%;塌落程度与细粒含量成正比,最小塌落为1.7 mm,最大塌落为6.15 mm.入堆矿石粒径极大影响着柱浸体系的浸出效果.实验中柱浸B组(粒径r<1 mm占28.41%)浸矿效果最佳,浸矿480 h后铜浸出率达47.23%.
Bioleaching is one of the most effective methods of extracting valuable elements from low-grade,refractory secondary copper sulfide. In this research,Acidithiobacillus ferrooxidans was used to leach refractory secondary copper sulfide from Fujian Province. The bioleaching microorganisms were added to the culture,domesticated,and column leaching experiments. These were based on different particle size ratios and carried out sequentially. Based on this experiments,the evolution disciplinarians of bacterial concentration,pH values and copper extraction rates were obtained at different stages. Using computed tomography(CT) technology,ore heap slumping inside the columns,cross section porosity evolution and leaching mechanisms were studied. The results indicate that bacterial concentration and pH values present trends that increase first and then stabilize. The proliferation of bacteria in the leaching columns is slower and the bacterial concentration is only 5 × 107 per m L after 480 h. During the leaching process,fine particles tend to move to the bottom of columns and the ore heap slump phenomenon appears. On the top surface of the column the porosity tends to begreater with increase rate of 6. 65%,conversely,this tends to be smaller at the column bottom,and its decreases rate is 8. 29%. The slump degree is proportional to the fines content; the minimum slump is 1. 7 mm and the maximum 6. 15 mm. Ore particle size is the key factor in the leaching process; column B(with particle size r < 1 mm accounted for 28. 41% of whole ores quality) shows the best copper extraction rate of 47. 23% after 480 h.
Bioleaching is one of the most effective methods of extracting valuable elements from low-grade,refractory secondary copper sulfide. In this research,Acidithiobacillus ferrooxidans was used to leach refractory secondary copper sulfide from Fujian Province. The bioleaching microorganisms were added to the culture,domesticated,and column leaching experiments. These were based on different particle size ratios and carried out sequentially. Based on this experiments,the evolution disciplinarians of bacterial concentration,pH values and copper extraction rates were obtained at different stages. Using computed tomography(CT) technology,ore heap slumping inside the columns,cross section porosity evolution and leaching mechanisms were studied. The results indicate that bacterial concentration and pH values present trends that increase first and then stabilize. The proliferation of bacteria in the leaching columns is slower and the bacterial concentration is only 5 × 107 per m L after 480 h. During the leaching process,fine particles tend to move to the bottom of columns and the ore heap slump phenomenon appears. On the top surface of the column the porosity tends to begreater with increase rate of 6. 65%,conversely,this tends to be smaller at the column bottom,and its decreases rate is 8. 29%. The slump degree is proportional to the fines content; the minimum slump is 1. 7 mm and the maximum 6. 15 mm. Ore particle size is the key factor in the leaching process; column B(with particle size r < 1 mm accounted for 28. 41% of whole ores quality) shows the best copper extraction rate of 47. 23% after 480 h.
引文
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[9]Wen J K,Yao G C,Chen B W,et al.Effect of temperature on the activity of mineral-bioleaching microorganisms and the bioleaching rate of copper.J Univ Sci Technol Beijing,2009,31(3):295(温建康,姚国成,陈勃伟,等.温度对浸矿微生物活性及铜浸出率的影响.北京科技大学学报,2009,31(3):295)
[10]Wu A X,Li X W,Yin S H,et al.Interface effects of unsaturated seepage in dump leaching.J Univ Sci Technol Beijing,2013,35(7):844(吴爱祥,李希雯,尹升华,等.矿堆非饱和渗流中的界面作用.北京科技大学学报,2013,35(7):844)
[11]Quast K,Xu D F,Skinner W,et al.Column leaching of nickel laterite agglomerates:effect of feed size.Hydrometallurgy,2013,134-135:144
[12]Yin S H,Wu A X,Su Y D,et al.Experimental study on preferential solution flow during dump leaching of low-grade ores.J Cent South Univ Technol,2007,14(4):584
[13]Nazari B,Jorjani E,Hani H,et al.Formation of jarosite and its effect on important ions for Acidithiobacillus ferrooxidans bacteria.T Nonferr Metal Soc China,2014,24(4):1152
[14]Miller J D,Lin C L,Garcia C,et al.Ultimate recovery in heap leaching operations as established from mineral exposure analysis by X-ray microtomography.Int J Miner Process,2003,72(1-4):331
[15]Lin C L,Miller J D,Garcia C.Saturated flow characteristics in column leaching as described by LB simulation.Miner Eng,2005,18(10):1045
[16]Lin C L,Miller J D.Pore structure analysis of particle beds for fluid transport simulation during filtration.Int J Miner Process,2004,73(2-4):281
[17]Yin S H,Xue Z L,Wu A X,et al.Mesoscopic seepage velocity characteristics during heap leaching based on magnetic resonance imaging.Chin J Eng,2015,37(3):275(尹升华,薛振林,吴爱祥,等.基于核磁共振成像技术的堆浸细观渗流速度场特性.工程科学学报,2015,37(3):275)
[18]Hu K J,Wang H J,Li G Z,et al.Improvement experiment study of alkaline copper leaching bacteria.Chin J Eng,2015,37(11):1410(胡凯建,王洪江,李广泽,等.一株碱性产氨浸铜细菌改良试验研究.工程科学学报,2015,37(11):1410)
[19]Wu A X,Yao G H,Xue Z L,et al.Seepage behavior of column leaching of copper oxide ore based on particles fabric characteristics.J Cent South Univ Sci Technol,2014,45(5):1605(吴爱祥,姚高辉,薛振林,等.基于颗粒群组构特性的氧化铜矿柱浸渗流行为分析.中南大学学报(自然科学版),2014,45(5):1605)
[20]Liu J.Effect of p H on the Extracellular Polymeric Substances and Adhesion from Acidithiobacillus Ferrooxidans[Dissertation].Changsha:Central South University,2013(刘晶.p H对嗜酸氧化亚铁硫杆菌分泌胞外多聚物及其吸附性能的影响[学位论文].长沙:中南大学,2013)
[21]Klauber C.Fracture-induced reconstruction of a chalcopyrite(Cu Fe S2)surface.Surf Interface Anal,2003,35(5):415
[22]Zhu C J,Lu J J,Lu X C,et al.SEM study on jarosite mediated by thiobacillus ferrooxidans.Geol J China Univ,2005,11(2):234(朱长见,陆建军,陆现彩,等.氧化亚铁硫杆菌作用下形成的黄钾铁矾的SEM研究.高校地质学报,2005,11(2):234)
[23]Liu X Y,Shu R B,Chen B W,et al.Bacterial community structure change during pyrite bioleaching process:effect of p H and aeration.Hydrometallurgy.2009,95(3-4):267
[24]Thomas G,Ingraham T R,Mac Donald R J C.Kinetics of dissolution of synthetic digenite and chalcocite in aqueous acidic ferric sulphate solution.Can Metall Quart,1967,6(3):281
[25]Rodrguez Y,Ballester A,Blazquez M L,et al.New information on the chalcopyrite bioleaching mechanism at low and high temperature.Hydrometallurgy,2003,71(1-2):47
[26]Wu A X,Yin S H,Qin W Q,et al.The effect of preferential flow on extraction and surface morphology of copper sulphides during heap leaching.Hydrometallurgy,2009,95(1-2):76
[27]Faybishenko B A.Hydraulic behavior of quasi-saturated soils in the presence of entrapped air:laboratory experiments.Water Resour Res,1995,31(10):2421
[28]Wu A X,Yin S H,Yang B H,et al.Study on preferential flow in dump leaching of low-grade ores.Hydrometallurgy,2007,87(3-4):124
[29]Hamdona S K,Hadad U A A.Crystallization of calcium sulfate dihydrate in the presence of some metal ions.J Cryst Growth,2007,299(1):146
[30]Yen Y K,Lin C L,Miller J D.Particle overlap and segregation problems in on-line coarse particle size measurement.Powder Technol,1998,98(1):1
[2]Panda S,Biswal A,Mishra S,et al.Reductive dissolution by waste newspaper for enhanced meso-acidophilic bioleaching of copper from low grade chalcopyrite:a new concept of biohydrometallurgy.Hydrometallurgy,2015,153:98
[3]Lai S S,Qin W Q,Yang C R,et al.Bioleaching of low grade copper sulfide ore.Chin J Nonferrous Met,2011,21(6):1473(赖绍师,覃文庆,杨聪仁,等.低品位硫化铜矿的细菌浸出.中国有色金属学报,2011,21(6):1473)
[4]Li H X,Cang D Q,Chen J H,et al.Effect of biological factors on heap bioleaching kinetics of secondary copper sulfide.Chin J Nonferrous Met,2007,17(2):331(李宏煦,苍大强,陈景河,等.生物因素对次生硫化铜矿堆浸过程动力学的影响.中国有色金属学报,2007,17(2):331)
[5]Fagan M A,Ngoma I E,Chiume R A,et al.MRI and gravimetric studies of hydrology in drip irrigated heaps and its effect on the propagation of bioleaching micro-organisms.Hydrometallurgy,2014,150:210
[6]Deng Q J,Zhu W Y,Wang X F,et al.Seepage model considering micro forces in porous media.J Univ Sci Technol Beijing,2014,36(4):415(邓庆军,朱维耀,王小锋,等.多孔介质中微观力的作用及渗流模型.北京科技大学学报,2014,36(4):415)
[7]Yin S H,Wang L M,Chen X.Effects of ore particle sizes on leaching regularities of secondary copper sulfide.J Cent South Univ Sci Technol,2015,46(8):2771(尹升华,王雷鸣,陈勋.矿石粒径对次生硫化铜矿浸出规律的影响.中南大学学报(自然科学版),2015,46(8):2771)
[8]Yin S H,Wang L M,Chen X,et al.Effect of ore size and heap porosity on capillary process inside leaching heap.T Nonferr Metal Soc China,2016,26(3):835
[9]Wen J K,Yao G C,Chen B W,et al.Effect of temperature on the activity of mineral-bioleaching microorganisms and the bioleaching rate of copper.J Univ Sci Technol Beijing,2009,31(3):295(温建康,姚国成,陈勃伟,等.温度对浸矿微生物活性及铜浸出率的影响.北京科技大学学报,2009,31(3):295)
[10]Wu A X,Li X W,Yin S H,et al.Interface effects of unsaturated seepage in dump leaching.J Univ Sci Technol Beijing,2013,35(7):844(吴爱祥,李希雯,尹升华,等.矿堆非饱和渗流中的界面作用.北京科技大学学报,2013,35(7):844)
[11]Quast K,Xu D F,Skinner W,et al.Column leaching of nickel laterite agglomerates:effect of feed size.Hydrometallurgy,2013,134-135:144
[12]Yin S H,Wu A X,Su Y D,et al.Experimental study on preferential solution flow during dump leaching of low-grade ores.J Cent South Univ Technol,2007,14(4):584
[13]Nazari B,Jorjani E,Hani H,et al.Formation of jarosite and its effect on important ions for Acidithiobacillus ferrooxidans bacteria.T Nonferr Metal Soc China,2014,24(4):1152
[14]Miller J D,Lin C L,Garcia C,et al.Ultimate recovery in heap leaching operations as established from mineral exposure analysis by X-ray microtomography.Int J Miner Process,2003,72(1-4):331
[15]Lin C L,Miller J D,Garcia C.Saturated flow characteristics in column leaching as described by LB simulation.Miner Eng,2005,18(10):1045
[16]Lin C L,Miller J D.Pore structure analysis of particle beds for fluid transport simulation during filtration.Int J Miner Process,2004,73(2-4):281
[17]Yin S H,Xue Z L,Wu A X,et al.Mesoscopic seepage velocity characteristics during heap leaching based on magnetic resonance imaging.Chin J Eng,2015,37(3):275(尹升华,薛振林,吴爱祥,等.基于核磁共振成像技术的堆浸细观渗流速度场特性.工程科学学报,2015,37(3):275)
[18]Hu K J,Wang H J,Li G Z,et al.Improvement experiment study of alkaline copper leaching bacteria.Chin J Eng,2015,37(11):1410(胡凯建,王洪江,李广泽,等.一株碱性产氨浸铜细菌改良试验研究.工程科学学报,2015,37(11):1410)
[19]Wu A X,Yao G H,Xue Z L,et al.Seepage behavior of column leaching of copper oxide ore based on particles fabric characteristics.J Cent South Univ Sci Technol,2014,45(5):1605(吴爱祥,姚高辉,薛振林,等.基于颗粒群组构特性的氧化铜矿柱浸渗流行为分析.中南大学学报(自然科学版),2014,45(5):1605)
[20]Liu J.Effect of p H on the Extracellular Polymeric Substances and Adhesion from Acidithiobacillus Ferrooxidans[Dissertation].Changsha:Central South University,2013(刘晶.p H对嗜酸氧化亚铁硫杆菌分泌胞外多聚物及其吸附性能的影响[学位论文].长沙:中南大学,2013)
[21]Klauber C.Fracture-induced reconstruction of a chalcopyrite(Cu Fe S2)surface.Surf Interface Anal,2003,35(5):415
[22]Zhu C J,Lu J J,Lu X C,et al.SEM study on jarosite mediated by thiobacillus ferrooxidans.Geol J China Univ,2005,11(2):234(朱长见,陆建军,陆现彩,等.氧化亚铁硫杆菌作用下形成的黄钾铁矾的SEM研究.高校地质学报,2005,11(2):234)
[23]Liu X Y,Shu R B,Chen B W,et al.Bacterial community structure change during pyrite bioleaching process:effect of p H and aeration.Hydrometallurgy.2009,95(3-4):267
[24]Thomas G,Ingraham T R,Mac Donald R J C.Kinetics of dissolution of synthetic digenite and chalcocite in aqueous acidic ferric sulphate solution.Can Metall Quart,1967,6(3):281
[25]Rodrguez Y,Ballester A,Blazquez M L,et al.New information on the chalcopyrite bioleaching mechanism at low and high temperature.Hydrometallurgy,2003,71(1-2):47
[26]Wu A X,Yin S H,Qin W Q,et al.The effect of preferential flow on extraction and surface morphology of copper sulphides during heap leaching.Hydrometallurgy,2009,95(1-2):76
[27]Faybishenko B A.Hydraulic behavior of quasi-saturated soils in the presence of entrapped air:laboratory experiments.Water Resour Res,1995,31(10):2421
[28]Wu A X,Yin S H,Yang B H,et al.Study on preferential flow in dump leaching of low-grade ores.Hydrometallurgy,2007,87(3-4):124
[29]Hamdona S K,Hadad U A A.Crystallization of calcium sulfate dihydrate in the presence of some metal ions.J Cryst Growth,2007,299(1):146
[30]Yen Y K,Lin C L,Miller J D.Particle overlap and segregation problems in on-line coarse particle size measurement.Powder Technol,1998,98(1):1