Acid equilibrium during bioleaching of alkaline low-grade sulfide copper ore

This article reports the study on acid equilibrium during bioleaching of alkaline low-grade copper sulfide ore. Adding auxiliary agents 1# （sulfur） and 2# （pyrite） makes bacterial leaching of copper and acid production carried out simultaneously because the auxiliary agents can be oxidized by bacteria and the oxidation products involve acid. The acid required for dissolving alkaline gangue during bacterial leaching is produced, and acid equilibrium is reached during the ore bio-leaching. The recovery of copper reaches more than 95%.     

高效浸矿混合菌种的筛选及其在浸矿过程中的微生物群落结构演变

为了筛选可高效浸出低品位硫化矿的混合菌株,从10个典型的硫化矿矿区的酸性矿坑水中分离富集到混合菌株。以浸出率作为筛选的主要标准,筛选后的高效菌株,利用群落基因组芯片分析混合菌群的组成和过程变化。浸矿持续进行24d后,采集自江西德兴银山铅锌矿的混合菌浸出率最高,为68.89%。群落基因组芯片结果表明银山菌群包含9种菌,可被分为6类,在浸出过程中群落始终在变化。该研究为加速浸出和了解浸出过程中群落演替提供了一个较好的方法。     

Effect of two kinds of amino-acids on bioleaching metal sulfide

By adding suitable amount of amino acid L-cysteine to acidic solution in contact with sphalerite or pyrite,the activity of Thiobacillus Ferrooxidans is largely enhanced. But, at comparable higher concentration of L-cysteine, a deleterious effect on bacterial activity was found, which can be due to the toxic effect of this amino acid at higher concentrations to microbes. The addition of L-methionine would be great inhibition to the bioleaching no matter how much it was applied, which indicates that L-methionine is harmful for bioleaching. The quite different effect on bioleaching between L-cysteine and L-methionine lies in that L-cysteine has a SH group which is useful in helping metal sulfide bioleaching by Thiobacillus ferrooxidans.     

Role of ore mineralogy in optimizing conditions for bioleaching low-grade complex sulphide ores

The role that ore mineralogy plays in understanding and optimizing the conditions favouring the bioleaching of complex sulphide ore containing high amounts of siderite was studied using mixed cultures of mesophilic bacteria, with emphasis on zinc, lead and copper recoveries. The influencing parameters investigated include particle size, stirring speed, volume of inoculum, pulp density, and pH. The results show that the mixed mesophilic cultures can extract about two and a half times the amount of zinc than copper over an equivalent period of time. The highest zinc and copper recoveries of 89.2% and 36.4% respectively are obtained at particle size of 75 lam, stirring speed of 150 r/min, pulp density of 10% （w/v）, 12% （v/v） inoculum concentration, and a pH of 1.6. Variations in elemental composition within different particle sizes resulting from the mineralogy of the ore account for the bioleaehing behaviour at varying particle sizes. The dissolution at varying pulp density, volume ofinoculum, solution pH and the low solution potential observed are also influenced by ore mineralogy.     

源自硫化矿区的Acidiphilium属菌的分离及其浸矿性能

从湖北大冶铜矿的铜山口硫化矿矿坑水中分离得到了一株嗜酸兼性异养细菌,暂命名为DY.该菌株为革兰氏阴性细菌,短杆状,菌体大小为(0.4±0.1)μm×(1.2±0.2)μm,最适生长温度为30 ℃,最适初始生长pH值为3.5,能利用葡萄糖、乳糖、蔗糖和单质硫生长,不能利用FeSO4进行生长.其系统发育树结果表明,菌株DY与Acidiphilium cryptum(Y18446)位于系统发育树的同一分支中,相似度为99.69%.黄铜矿(CuFeS2)摇瓶细菌浸出实验显示,DY菌株单独浸出黄铜矿的能力较弱,但和嗜酸自养的氧化亚铁硫杆菌ATCC 23270混合浸矿时,与氧化亚铁硫杆菌单独浸矿相比,30 d后黄铜矿的浸出率提高了35.98%.     

元素硫对黄铜矿生物浸出行为及群落结构的影响(英文)

研究3种典型铁/硫代谢菌—Acidithiobacillus ferrooxidans,Leptospirillum ferriphilum及Acidithiobacillus thiooxidans混合浸出黄铜矿过程中铁/硫氧化活性、群落结构(PCR-RFLP)的变化,以及不同浓度的元素硫对其影响。结果发现,加入3.193g/L元素硫能促进细菌的表观硫氧化活性,改变浸矿体系的群落结构,并进一步影响钝化层的形成、金属离子的溶出,其浸出率(71%)较未添加硫的(67%)有一定程度的提高。而过量的元素硫会抑制铜的浸出(浸出率44%)。     

诱变对新菌株Leptospirillum ferriphilum YXW及浸出金矿的影响

通过稀释分离方法从江西德兴铜矿矿山废水中富集而来的混合菌中分离得到菌株 Leptospirillum ferriphilum YXW,再利用超声波、紫外线和微波对其进行诱变,筛选出更高效的细菌用于金矿的浸出。生理生化特性实验显示,菌株YXW为极端化能自养型细菌,最佳的生长条件为温度40°C,pH=1.5。诱变后,细菌浓度分别可达到9×109(超声波)、8.4×109(紫外线)和4.3×108 mL?1(微波),与原始菌相比,分别提高了291%、265%和87%。微波和紫外诱变后,细菌总蛋白活性升高,而超声诱变后,细菌总蛋白活性降低。诱变对细菌浸出金矿的影响由大到小的排列顺序是微波、紫外线、超声波。在金矿浸出过程中,微波诱变后的细菌具有最好的浸出效果。浸出10 d后,As和Fe的浸出率分别高出原始菌19.6%和17.7%。结果表明,诱变对细菌浸出金矿效果的提高,可能不在于细菌浓度的增大,而是取决于细菌总蛋白活性的提高。     

Bioleaching of refractory gold ore （ Ⅱ ）——Mechanism on bioleaching of arsenopyrite by Thiobacillus ferrooxidans

1　ＩＮＴＲＯＤＵＣＴＩＯＮＢｉｏｌｅａｃｈｉｎｇｐｒｏｃｅｓｓｅｓｈａｖｅｂｅｅｎｕｓｅｄｅｘｔｅｎｓｉｖｅｌｙｔｏｒｅｃｏｖｅｒｂａｓｅｍｅｔａｌｓ (ｍａｉｎｌｙｃｏｐｐｅｒ)ａｎｄｕｒａｎｉｕｍｆｒｏｍｌｏｗ ｇｒａｄｅｏｒｅｓａｎｄｍｏｒｅｒｅｃｅｎ     

膜生物反应器浸出镍钼矿

采用对钼有一定耐受性的嗜热金属硫叶菌结合膜反应器浸出镍钼矿。结果表明：由于膜生物反应器（MBR）中膜的过滤作用,使浸出液中的钼浓度保持在该菌可以耐受的范围内,从而实现细菌对矿物相对高效的浸出。在矿浆浓度100mg/L、通气量1.0L/min下,将MBR浸出液中钼被控制在不同浓度,镍、钼的浸出率各不相同。当MBR浸出液中钼的浓度不超过395mg/L时,镍和钼的浸出率达到79.57%和56.23%;而在相同条件下的柱浸,镍、钼浸出率为75.59%和54.33%,低于相同条件下MBR浸出。     

Catalytic effect of activated carbon on bioleaching of low-grade primary copper sulfide ores

The catalytic effect of activated carbon on the bioleaching of low-grade primary copper sulfide ores using mixture of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans was investigated. The results show that the addition of activated carbon can greatly accelerate the rate and efficiency of copper dissolution from low-grade primary copper sulfide ores. The solution with the concentration of 3.0 g/L activated carbon is most beneficial to the dissolution of copper. The resting time of the mixture of activated carbon and ores has an impact on the bioleaching of low-grade primary copper sulfide ores. The 2 d resting time is most favorable to the dissolution of copper. The enhanced dissolution rate and efficiency of copper can be attributed to the galvanic interaction between activated carbon and chalcopyrite. The addition of activated carbon obviously depresses the dissolution of iron and the bacterial oxidation of ferrous ions in solution. The lower redox potentials are more favorable to the copper dissolution than the higher potentials for low-grade primary copper sulfide ores in the presence of activated carbon.     

嗜酸兼性异养菌Acidiphilium sp.DX1-1的分离、特征及其浸矿行为(英文)

研究了一株源自江西德兴铜矿矿区的中温嗜酸兼性异养菌Acidiphilium sp.DX1-1的分离、鉴定、特征及其浸矿行为。菌株Acidiphilium sp.DX1-1为短杆状革兰氏阴性菌,最适合的生长温度为30℃,最适合的生长pH约为3.5。该菌株具有广泛的底物利用特性,可以利用有机物进行异养生长并在细胞内积累聚羟基丁酸酯,也可以利用单质硫、三价铁等无机物进行自养生长。系统发育分析表明DX1-1属于Acidiphilium属,与Acidiphilium cryptum and Acidiphilium multivorum的同源性大于99%。在铁闪锌矿生物浸出过程中,Acidiphilium sp.DX1-1表现出极强的浸矿能力,其作用不仅仅是之前报道的作为其他自养嗜酸浸矿细菌的辅助者。在初始pH3.5时,DX1-1能够在一个月内单独地浸出铁闪锌矿中40%的锌。该浸出率高于它与A.ferrooxidans混合以及A.ferrooxidans单独浸出铁闪锌矿(初始pH均为2.0)的浸出率。     

Comparative study on bioleaching of two different types of low-grade copper tailings by mixed moderate thermophiles

The bioleaching of two different types of low-grade copper tailings, acid-leaching tailings (ALT) and copper flotation tailings (CFT) by mixed moderate thermophiles, and the variation of mineralogical and microbiological characteristics during their dissolution processes were comparatively investigated. Results showed that bioleaching behaviors of the two types of tailings were significantly different. In ALT bioleaching, lower redox potential, higher [Fe³⁺]/[Fe²⁺] ratio and higher cell density in solution were obtained. These resulted in higher total copper, primary copper sulfide and secondary copper sulfide extractions, compared with CFT bioleaching. X-ray diffraction analysis suggested that gypsum and some metal organic complexes were detected in CFT bioleaching, which could cause the sluggish oxidation of sulphide minerals. The shifts of microbial community in the leachates and leaching residues varied greatly between ALT and CFT bioleaching. The percentage of iron-oxidizing bacteria in ALT bioleaching was higher than that of CFT, but the sulfur-oxidizing bacteria percentage was the opposite. The archaeon F. thermophilum L1 was detected in ALT but not in CFT.     

Behavior of Fe and S in bioleaching of pentlandite

1　ＩＮＴＲＯＤＵＣＴＩＯＮＯｘｉｄｉｚｉｎｇｐｒｏｃｅｓｓｂｙａｕｔｏｔｒｏｐｈｉｃｂａｃｔｅｒｉａ ,ｓｕｃｈａｓＴｈｉｏｂａｃｉｌｌｕｓｆｅｒｒｏｏｘｉｄａｎｓ (Ｈｅｒｅｉｎｂｅｌｏｗｂｅａｂｂｒｅ ｖｉａｔｅｄｔｏＴ .ｆ .) ,ｈａｓｂｅｅｎｗｉｄｅｌｙ     

Effect of technological factors on bacterial leaching of low-grade Ni-Cu sulfide ore

1　ＩＮＴＲＯＤＵＣＴＩＯＮＢａｃｔｅｒｉａｌｌｅａｃｈｉｎｇｗｉｔｈａｕｔｏｔｒｏｐｈｉｃｂａｃｔｅｒｉａ ,ｓｕｃｈａｓＴｈｉｏｂａｃｉｌｌｕｓｆｅｒｒｏｏｘｉｄａｎｓ (Ｔ .ｆ.) ,ｈａｓｂｅｅｎｅｘｔｅｎｄｅｄｔｏｓｏｍｅｐｏｌｙｍｅｔａｌｌｉｃｓｕｌｆｉｄｅｏｒｅｓ[1] .ＡｆｅｗｏｆｐａｐｅｒｓｏｎｂｉｏｌｅａｃｈｉｎｇｏｆＮｉ Ｃｕｓｕｌｆｉｄｅｏｒｅｗｅｒｅｐｕｂｌｉｓｈｅｄ .Ｔｏｒｍａ[2 ] ｒｅｐｏｒｔｅｄｔｈａｔｔｈｅｌｅａｃｈｅｄＮｉ,ＣｕａｎｄＣｏｗｅｒｅａｌｌｏｖｅｒ 6 0 %ｉｎ 10ｄ…     

黄铁矿、单质硫、亚铁离子对浸矿微生物产生胞外多聚物的影响(英文)

嗜酸浸矿微生物产生的胞外多聚物(EPS)在酸性矿坑水的产生和硫化矿的浸出过程中,有着非常重要的影响,胞外多聚物(EPS)介导细胞与能源物质的接触,对有机薄膜的形成和细菌与基础物之间的相互作用起着重要的作用。对7株浸矿菌在不同能源培养物下产生的EPS的量以及EPS的化学成分进行研究,发现EPS含有化学成分糖、蛋白质、糖醛酸等,细菌的种类和能源物质对EPS的量和成分有很大影响。结果表明,以黄铜矿为能源物质的细菌产生的EPS要比以单质硫和亚铁为能源物质产生的EPS量多,EPS含量最高为(159.43±3.93)mg/g,是由Leptospirillum ferriphilum CBCBSUCSU208015在黄铁矿为能源物质下产生的。     

Simulated small-scale pilot heap leaching of low-grade copper sulfide ore with selective extraction of copper

The bioleaching of low-grade copper sulfide ore and the selective extraction of copper were investigated. Lix984 dissolved in kerosene was used as extractant. The results show that it is possible to selectively leach copper from the ores by heap leaching. The copper concentration of leaching liquor after 250 d is 2.17 g/L, and the copper concentration is 0.27 g/L after solvent extraction. The leach liquor was subjected to solvent extraction, scrubbing and selective stripping for the enrichment of copper and the removal of impurities. The pregnant copper sulfate solution produced from the stripping cycle is suitable for copper electro-winning.     

生物浸出过程中黄铜矿钝化的控制方法(英文)

在细菌浸出黄铜矿的过程中,黄铜矿表面钝化是普遍现象,成为生物浸铜技术的瓶颈问题。对比研究了普通浸出与强化浸出(加入玻璃圆珠)对铜浸出的影响。结果表明,玻璃圆珠的加入改善了浸出条件,削弱了黄铜矿的钝化效应,使黄铜矿的Cu浸出率从50%提升至 89.8%。扫描电镜(SEM)和X射线衍射(XRD)分析发现,添加玻璃圆珠的黄铜矿表面没有黄钾铁矾沉淀,钝化作用不明显;而不加玻璃圆珠的黄铜矿表面附着厚厚的结构致密的黄钾铁矾,钝化严重,从而阻碍了黄铜矿的溶解和浸出。     

微生物浸出Pb-Zn-Sn黄铜矿及其生物群落的演替分析

研究了Pb-Zn-Sn黄铜矿精矿在混合中度嗜热微生物槽浸过程中的细菌群落结构变化,并监测浸出体系中金属离子浓度、溶液电位、溶液pH值变化,通过聚合酶链式反应-限制性片段长度多态性（PCR-RFLP）技术分析微生物群落的结构变化。结果表明,最终铜浸出率高达85.6%,在浸出前期,Acidithiobacillus caldus为优势群落,从第18天开始到浸出结束,Sulfobacillus thermosulfidooxidans为优势群落,但Leptospirillum ferriphilum丰度变化较小。试验结果表明,适当较高的溶液电位和合适的铁离子浓度对黄铜矿精矿的生物浸出作用很关键。     

Elective culture of bacteria used in bioleaching on pyrrhotite

1　ＩＮＴＲＯＤＵＣＴＩＯＮＢｉｏｈｙｄｒｏｍｅｔａｌｌｕｒｇｙｉｓｃｈａｒａｃｔｅｒｉｚｅｄｂｙｌｏｗｃｏｓｔ,ｓｈｏｒｔｆｌｏｗｓｈｅｅｔａｎｄｌｏｗｃｏｎｔａｍｉｎａｔｉｏｎ .Ｗｉｔｈｔｈｅｅｓｃａｌａｔ ｉｎｇｄｅｐｌｅｔｉｏｎｏｆｍｉｎｅｒａｌｓｏｕｒｃｅａｎｄｔｈｅｓｔｒｅｎｇｔｈｅｎｅｄｍｉｎｄｏｆｅｎｖｉｒｏｎｍｅｎｔａｌｃｏｎｓｅｒｖａｔｉｏｎ ,ｂｉｏｈｙｄｒｏｍｅｔａｌｌｕｒｇｙｐｒｅ ｓｅｎｔｓｍｏｒｅａｄｖａｎｔａｇｅｓｏｖｅｒｔｈｅｃｏｎｖｅｎｔｉｏｎａｌｍｅｔａｌｌｕｒｇ…     

细粒铜尾矿生物柱浸体系下细菌群落对潜在的铺矿形式的响应

比较研究分层铺筑(LM)、聚团铺筑(AM)和烧结球团铺筑(PM)三种铺矿形式对铜浮选尾矿生物柱浸的影响.解析尾矿浸出后期三组浸矿体系下游离、吸附、弱吸附和强吸附微生物的群落结构.在AM浸出组,用于尾矿聚团的块状硫化矿的添加使浸出溶液pH值降低,三价铁离子浓度升高和微生物快速吸附.相比于LM(54.6％)和PM(43.9...