不同类型黄铜矿的生物浸出研究

研究了两种不同类型(黄铁矿型,斑岩型)黄铜矿生物浸出的差异.实验结果表明:两类黄铜矿生物浸出差别很大,48 d后黄铁矿型黄铜矿浸出率为46.96%,斑岩型黄铜矿浸出率为14.5%.对Fe²⁺、矿物表面Cu2p谱图和矿床特征的分析发现:适量的Fe²⁺能促进黄铜矿的浸出,但最佳用量不一样;浸渣表面产物不同,斑岩型黄铜矿表面出现富铜层,阻碍了浸出继续进行;与原矿相比,铜结合能都降低,符合Hiroyoshi等提出黄铜矿浸出的两步溶解模型;两类黄铜矿生物浸出的差异是由成矿岩体、围岩、伴生矿物和元素、成矿温度和压力等因素综合决定的.     

脉石矿物对细菌浸出黄铜矿的影响研究

运用XRD,SEM-EDS等检测手段,采用摇瓶试验,以At.f菌作为浸矿细菌,研究了3种脉石矿物对黄铜矿细菌浸出的影响及机制。通过模拟实际铜尾矿中脉石矿物组成,得出了石英、绢云母、白云石对黄铜矿细菌浸出的影响规律。研究结果表明,石英、绢云母能促进黄铜矿微生物浸出,而白云石由于是碱性矿物,含量较高时它的抑制作用很明显。铜浸出率由高到低的脉石矿物组合是:石英-绢云母(45.71%)、空白(42.71%),石英-绢云母-白云石(30.16%)、石英-白云石(11.85%)、绢云母-白云石(10.75%)。浸渣的XRD及SEM-EDS分析表明,含脉石矿物石英时,新生成钝化物主要是黄钾铁矾,含绢云母时主要生成铵黄铁矾,含少量白云石时主要生成钙磷石、硫酸钙和非晶态的FeO(OH)。     

铝离子对氧化亚铁硫杆菌活性及浸出黄铜矿的影响

以氧化亚铁硫杆菌(Acidthiobacillus ferrooxidans,At.f)为研究对象,研究了铝离子浓度对黄铜矿浸出体系At.f菌氧化活性、黄铜矿表面吸附细菌数量以及铜浸出率的影响,并对其之间内在联系进行了考察。研究结果表明,浸出体系铝离子浓度在所研究的0~20 g·L~(-1)范围内,对细菌氧化活性的影响有明显差异。铝离子浓度为1 g·L~(-1)时,细菌氧化活性最好,浸出15 d后,体系氧化还原电位便可由381 mV升高到588 mV左右,Fe~(2+)氧化率达到98.49%,体系pH值由2.11下降到1.44;超过1 g·L~(-1)后,细菌氧化活性逐渐降低,Fe~(2+)氧化率下降,铝离子浓度为20 g·L~(-1)时,浸出45 d后,体系氧化还原电位仅为400 mV左右,Fe~(2+)氧化率也仅为40%左右。矿物表面吸附细菌数量、浸出体系铜浸出率均随铝离子浓度增加先升高后降低,铝离子浓度为15 g·L~(-1)时,浸出体系铜离子浸出率最高,可达71.39%,矿物表面吸附细菌数量也最多,表明铜浸出率与矿物表面吸附细菌数量正相关。     

石英对微生物浸出黄铜矿的作用

为探明石英在微生物浸出铜过程中的作用与影响,选择粒度<43μm的石英,与黄铜矿和黄铁矿形成矿浆浸出体系,考察了石英质量浓度对黄铜矿浸出效果的影响.结果表明:适量的石英,其粒度越细越能促进黄铜矿的浸出.当石英质量浓度为50g·L^-1、粒度<43μm时,黄铜矿的浸出率最高可达54.09%,比不添加石英的浸出率提高了近20%;通过对微生物浸出过程的氧化还原电位、pH值、Fe²⁺、Fe³⁺变化分析,以及浸渣的扫描电镜和能谱分析发现,石英促进黄铜矿浸出主要表现在能缩短微生物浸出的延迟时间,它对浸出过程新生成的沉淀具有吸附作用,能在一定程度上减轻沉淀对黄铜矿浸出的阻碍.     

活性炭催化低品位原生硫化铜矿石酸浸研究

根据电化学原理,研究了活性炭催化低品位原生硫化铜矿石酸浸效果。结果表明,添加活性碳可以大大加快铜的浸出速度并提高铜浸出率;初始活性碳质量浓度为5.0g/L,最有利于铜的浸出;浸出240h后,铜浸出率升高到83%,比不添加活性炭时提高了近80%。活性碳加快浸铜速度并提高铜浸出率的原因是活性碳与黄铜矿之间形成了原电池。当有活性碳存在时,低品位原生硫化铜矿石在低氧化还原电位下比高氧化还原电位下更有利于浸出。     

中等嗜热菌浸出黄铜矿的影响因素研究

研究了45℃条件下利用中等嗜热菌浸出黄铜矿(75.5%,CuFeS2)过程中的影响因素.结果发现适当的初始pH值有利于细菌浸出,矿浆浓度和矿物粒度对细菌浸出过程的影响较大;另外初始添加适量Fe2+有助于细菌生长和提高浸出效率,但是过量添加会导致生成的黄钾铁矾沉淀阻碍浸出.初始细菌浓度、培养基和水的配比及浸出时间对浸出过程存在不同程度的影响,初始细菌浓度在1×106 cell·ml-1时浸出率最高,黄铜矿的浸出率可以达到64.20%,培养基和水的不同配比对细菌生长和浸出过程影响不是很大,浸出40 d时,铜浸出率可以达到80%以上.     

细菌浸出黄铜矿过程中黄铁矿的影响行为

内蒙古硫铁矿伴生黄铜矿的东升庙和霍格气两大矿区 ,黄铁矿含量不同。本文对氧化亚铁硫杆菌 ( Thiobacillus ferrooxidans)浸出黄铜矿过程中黄铁矿的影响及其机理进行了探讨。通过黄铁矿含量不同的两种矿物进行浸铜率和铜的溶解速度、反应液中铁离子的价态变化、三价铁的沉淀、用扫描电镜观察矿物颗粒表面细菌的吸附、X射线粉末衍射仪测定两种矿物反应前后的物相变化等多方面做了较为详细的研究。结果表明 ,黄铁矿对细菌浸出黄铜矿有抑制作用。     

难处理低品位铜钴矿的微生物浸出

以赞比亚某典型难处理低品位氧化铜钴矿为研究对象,配入适量硫化铜钴矿,采用人工调配的高效微生物浸矿菌群对铜钴矿进行微生物浸出,同时分别与摇瓶酸浸、搅拌酸浸和柱浸进行了对比.结果表明,采用微生物浸出难处理铜钴矿,随着温度升高和时间延长,铜浸出率增大.浸出温度为40℃时,微生物浸出铜浸出率为90.7%,高于摇瓶酸浸和搅拌酸浸浸出结束时浸出率(69.4%~73.2%)以及柱浸结束时浸出率(约85%).由于微生物浸出群落对该难处理铜钴矿作用时间周期较长,适用于堆浸生产.细菌的存在使得铁离子不断的在二价与三价间循环,通过具有强氧化性的Fe3+与硫化矿物相互作用,使得矿物分解,提高浸出率.     

铜冶炼烟灰碱浸渣氨浸工艺

以铜冶炼烟灰碱浸渣为原料,研究氨-硫酸铵体系的 pH 值、总氨浓度、氨铵摩尔比、液固质量比、反应温度、反应时间等因素对铜冶炼烟灰碱浸渣中铜锌浸出的影响规律.结果表明,最佳工艺条件为:总氨浓度为 5 mol/L、pH 值为 10、氨铵摩尔比为 2:1、液固质量比为 5:1,浸出温度为 70 ℃,浸出时间为 60 min.此条件下铜和锌浸出率分别为 90.6 %和 92.4 %.      

微生物浸出法从石煤提钒尾渣中回收钒和铜的研究

中国堆存的石煤提钒尾渣量高达数十亿吨,尾渣中含有钒、铜等多种金属,高效回收尾渣中有价金属既可以实现其资源化,同时防止尾渣污染周边环境。本文采用微生物浸出技术回收石煤提钒尾渣中有价金属V和Cu,重点研究了不同初始pH、溶氧量(以摇床转速表征)、黄铁矿添加量、浸出时间等不同因素对氧化亚铁硫杆菌(T.f菌)浸出尾渣中金属钒、铜的影响。结果表明,初始pH 2～4范围内对V,Cu浸出率影响不大,较高的摇床转速有利于V,Cu的浸出;在初始pH为2、摇床转速170 r·min^-1、黄铁矿添加量15 g·L^-1的条件下,T.f菌浸出尾渣10天后,V和Cu浸出率分别达到83.4%和87.8%,相比单独酸浸体系,V和Cu浸出率分别提高了32.6%和17.92%,说明T.f菌在浸出石煤提钒尾渣过程中起了关键作用。研究结果将为推动微生物技术在石煤提钒尾渣资源化的稳定应用进程提供指导。     

黄铁矿强化生物浸出低品位磷矿

进行了嗜酸氧化亚铁硫杆菌、嗜酸氧化硫硫杆菌与嗜酸氧化亚铁钩端螺旋菌的混合菌强化浸出低品位磷矿的实验研究.结果表明:由于试样中硫含量低,不利于该磷矿的生物浸出.提出了在浸矿体系中添加黄铁矿来强化浸出的措施.考察了细菌种类、磷矿与黄铁矿配比以及初始Fe²⁺质量浓度等参数对磷浸出率的影响.采用驯化菌浸出该磷矿,能获得最佳的浸出效果,其适宜的工艺参数为初始Fe²⁺质量浓度9g·L^-1、磷矿与黄铁矿质量比1:2.5,经过20d浸出,磷的浸出率可达95%.     

含砷低品位硫化铜矿生物柱浸实验

介绍了含砷低品位硫化铜矿柱浸实验研究方法、装置和结果.实验在八根有机玻璃柱浸系统中进行,考察了细菌种类、矿石粒度、供氧条件及浸出周期等参数对浸出率的影响.结果表明,在-12mm粒度下,采用Z08090-O菌株浸出,浸出167d,铜浸出率为80.75%.对含大量黄铁矿且耗酸脉石少的矿石,酸的累积降低了采用普通驯化浸矿菌的铜浸出率,但采用激光诱变获得的耐低pH值浸矿菌,能够保持高效的铜浸出率.     

低温煅烧—强化细菌浸出废旧手机板中有色金属

研究煅烧预处理温度对嗜酸氧化亚铁硫杆菌浸出废旧手机板中多种有色金属的影响。结果表明,预处理温度越高,零价金属的浸出效率相对越高。生物浸出15天后,铜、镍和锌的浸出率分别达到95.14%、96.53%和98.45%,锡先溶解而后以沉淀形式存在于浸出残渣中。低温煅烧预处理不仅缩短了浸出周期,还提高了部分有色金属的浸出率。     

Fundamental studies of the contribution of galvanic interaction to acid-bacterial leaching of mixed metal sulfides

A systematic study has been made towards understanding the role of galvanic interactions in the leaching of sulfide minerals both in the absence and presence of bacteria. When two sulfide minerals are in contact with each other in an acid-aqueous solution, the mineral lower in the electromotive series dissolves rapidly while the one higher in the series is galvanically protected. To ascertain the magnitude of galvanic interaction when chalcopyrite (CuFeS₂) and pyrite (FeS₂) are in contact, potentiodynamic polarization measurements were carried out in 1 M H₂SO₄ and in Bryner and Anderson medium. The individual rest potentials of CuFeS₂ and FeS₂ were found to be 0.52 V and 0.63 V [vs. Standard Hydrogen Electrode (SHE)] respectively. The mixed potential of the CuFeS₂: FeS₂ couple was found to be 0.56 V and 0.28 V (vs. SHE) in 1 M H₂SO₄ and in Bryner and Anderson medium respectively. The corrosion current (5 μA/cm²) was calculated from the polarization curves. These results were found to be in agreement with the actual leaching rates of copper from contacting large mineral specimens composing the CuFeS₂/FeS₂ system.Both powdered samples as well as large mineral specimens of CuFeS₂, FeS₂ and ZnS were used to observe the effect of galvanic interactions on the process of leaching. Chalcopyrite and pyrite powders, as pulp mixtures, were leached under a variety of experimental conditions to optimize their ratio (total pulp density) and size fraction for efficient metal extraction by way of maximum contact with each other. A CuFeS₂:FeS₂ ratio of 5:5 (g/g) and size fraction of ?200 mesh was found to be the most preferable when leaching was carried out in the presence of T. ferrooxidans. The effect of temperature and thermophilic bacteria on the rate of leaching was also studied. The presence of pyrite in the optimized quantities considerably enhanced the rate of copper dissolution which was increased, by a factor of 2, to 15. Under these experimental conditions, E_h increased from 338 mV to 580 mV while pH dropped from 2.30 to 1.56.In order to have a definite control over surface area of the ores and a constant contact between two sulfide ores, large crystalline-mineral samples of CuFeS₂, FeS₂ and ZnS were leached singly as well as in intimate contact (coupled galvanically). This also made it possible to observe the surfaces of the specimens as the leaching proceeded in the presence of galvanic interaction. Coupled CuFeS₂/FeS₂, ZnS/FeS₂ and CuFeS₂/FeS₂/ZnS systems showed improved metal dissolution as compared to leaching of single large specimens.Scanning electron microscope observations showed that there were no major changes on pyrite surfaces when in galvanic contact with chalcopyrite and/or sphalerite. These observations have been supported by chemical data and by energy-dispersive X-ray analysis.     

黄铁矿对黄铜矿浸出的影响

常压条件下,黄铜矿浸出速率缓慢,难以达到理想的浸出效果。溶液中,黄铁矿与黄铜矿共同存在时,发生"原电池效应"可以促进黄铜矿溶解。探究了在H_2SO_4溶液、H_2SO_4-Fe_2(SO_4)_3溶液和H_2SO_4-H_2O_2溶液中,黄铁矿对黄铜矿浸出的影响。结果表明,黄铁矿可有效促进黄铜矿溶解,但浸出并不完全。在浸出过程中黄铜矿表面形成钝化层,影响物质转移与电子传递效果。钝化层的主要成分为缺金属硫化物和少量单质硫。     

紫金山铜矿生物堆浸过程酸铁平衡实践与优化方向

紫金山铜矿低品位矿石采用生物堆浸—萃取—电积工艺产出阴极铜。矿石中主要铜矿物为蓝辉铜矿及铜蓝,同时含有较高含量的黄铁矿,耗酸脉石含量低。铜矿物浸出过程中,伴随着黄铁矿的氧化产酸产铁,造成堆浸系统溶液中酸铁浓度的不断累积,影响到浸出、萃取及环保处理工序,需要通过不断地中和来降低酸铁浓度。介绍了紫金山铜矿生物堆浸的技术特点,对生物堆浸过程中高酸高铁和低酸低铁两种工艺实践中酸铁平衡实践进行总结;结合紫金山铜矿矿石矿物学信息,进行酸平衡计算,确定了堆浸过程中黄铁矿氧化过程对酸铁平衡的影响;分析工艺条件对酸铁平衡的影响,并提出未来解决酸铁过剩的工艺优化方向。     

Mechanism of enhanced bioleaching efficiency of Acidithiobacillus ferrooxidans after adaptation with chalcopyrite

To clarify the role and mechanism of bacterial adaptation in bioleaching, the leaching of chalcopyrite by adapted and unadapted Acidithiobacillus ferrooxidans was compared. Three extrinsic factors (adsorption, tolerance to shearing stress and copper tolerance) in relation to bioleaching were investigated. The results showed that there were significant differences in bacterial attachment and tolerance to shearing stress of unadapted and adapted cells due to the variation of cellular wall component and structure. Consequently, there was significant difference in bioleaching rate between unadapted and adapted bacteria. In addition, some differences of copper accumulation and distribution in adapted and unadapted cells also existed, but this was not one of the key factors that affected their bioleaching rates.     

表面活性剂吐温20对胶硫钼矿生物浸出的促进机理

为提高胶硫钼矿中钼的生物浸出效率,研究了非离子表面活性剂吐温20对氧化亚铁硫杆菌(A.ferrooxidans)的代谢活性以及胶硫钼矿生物浸出的影响,并采用X射线衍射、扫描电镜对浸出产物进行表征.研究结果表明,吐温20对A.ferrooxidans氧化Fe²⁺有明显的抑制作用,但对S⁰的氧化则表现出一定的促进作用.吐温20对胶硫钼矿生物浸出的作用表现为:低质量浓度促进,高质量浓度抑制,当其质量浓度为30 mg·L^-1时,浸出40 d,Mo的浸出率由未添加时的42.21%提高至54.10%.吐温20的加入强化了浸出过程中间产物S⁰的生物氧化作用,提高了体系中细菌浓度,同时削弱了矿物表面生成的黄钾铁矾和单质硫的钝化作用,从而促进了胶硫钼矿的氧化与溶解.