Effect of ultraviolet mutagenesis on heterotrophic strain mutation and bioleaching of low grade copper ore

The effect of ultraviolet mutagenesis on a heterotrophic strain(Providencia JAT-1) mutation was studied and bioleaching of low grade copper ore with mutant bacteria was investigated. The results show that the activity of bacteria was improved after ultraviolet mutagenesis; the best irradiation time was 120 s. Compared to the original bacteria, the cells density of mutant bacteria at stationary phase increased by 26% and ammonia produced by mutant bacteria increased by 12%. Higher activity of bacteria leads to a higher copper extraction rate. The bioleaching performance of Providencia JAT-1 was improved after UV mutagenesis. The copper extraction rate with mutant bacteria increased by 10.6% compared to the original bacteria. The ore surface was corroded and the fine particles were absent after bioleaching. Free copper oxide and copper silicates could be leached out easily by using JAT-1; a small part of the copper sulfide can also be leached out. Bioleaching using JAT-1 is more effective than ammonia leaching and copper extraction rate with mutant bacteria was 21.1% higher than that by ammonia leaching under the same condition.

Dissolution kinetics of low grade complex copper ore in ammonia-ammonium chloride solution

The leaching kinetics of Tang-dan refractory low grade complex copper ore was investigated in ammonia-ammonium chloride solution.The concentration of ammonia and ammonium chloride,the ore particle size,the solid-to-liquid ratio and the temperature were chosen as parameters in the experiments.The results show that temperature,concentration of ammonia and ammonium chloride have favorable influence on the leaching rate of copper oxide ores.But,leaching rate decreases with increasing particle size and solid-to-liquid ratio.The leaching process is controlled by the diffusion of the lixiviant and the activation energy is determined to be 23.279 kJ/mol.An equation was also proposed to describe the leaching kinetics.

Effect of copper slag recovery on hydrometallurgical cut-off grades considering environmental aspects

Determining the hydrometallurgical cut-off grades specifies the destination of low grade materials and this is subjected to more benefits in mining. Copper production rate is considered as one of the fundamental issues in hydrometallurgical cut-off grades determination. Slags are remarked as one of the main sources of copper. It is not only regarded as a waste but also identified as another resource extracting base metals. Slags are characterized by copper high grade. Thus, slag copper recovery can be led to different cut-off grades and net present value(NPV). The current research scrutinizes the effect of slag recovery by both flotation and hydrometallurgical methods on the hydrometallurgical cut-off grades. For this purpose, the optimum cut-off grade algorithms of hydrometallurgical methods are developed by considering associated environmental parameters, incomes and also the costs. Then, their optimum amounts are calculated with NPV maximization as an objective function. The results indicate that considering slag copper recovery in the hydrometallurgical cut-off grade algorithms reduces the environmental costs caused by slag dumping and leads to more NPV by 9%.

Optimization on selenium and arsenic conversion from copper anode slime by low-temperature alkali fusion process

A process was proposed to convert and separate selenium and arsenic in copper anode slime(CAS) by low-temperature alkali fusion process.Central composite design was employed to optimize the effective parameters,in which Na OH/CAS mass ratio,fusion temperature and fusion time were selected as variables,and the conversion ratio of selenium and arsenic as responses.Second-order polynomial models of high significance and 3D response surface plots were constructed to show the relationship between the responses and the variables.Optimum area of >90% selenium conversion ratio and >90% arsenic conversion ratio was obtained by the overlaid contours at Na OH/CAS mass ratio of 0.65-0.75,fusion temperature of 803-823 K and fusion time of 20-30 min.The models are validated by experiments in the optimum area,and the results demonstrate that these models are reliable and accurate in predicting the fusion process.

Enhanced copper recovery from low grade copper sulfide ores through bioleaching using residues produced by fermentation of agricultural wastes

Effects of residues produced by agricultural wastes fermentation(AWF)on low grade copper sulfide ores bioleaching,copper recovery,and microbial community were investigated.The results indicated that adding appropriate bulk of AWF made contributions to low grade copper sulfide ores bioleaching,which may be mainly realized through reducing the passivation layer formed by Fe3+hydrolysis.Improved copper recovery(78.35%)and bacteria concentration(9.56×10^(7)cells·mL^(−1))were yielded in the presence of 5 g·L^(−1)AWF.The result of 16S rDNA analysis demonstrated that microbial community was differentiated by adding AWF.Bacteria proportion,such as Acidithiobacillus ferrooxidans,Moraxella osloensis,and Lactobacillus acetotolerans changed distinctly.Great difference between samples was showed according to beta diversity index,and the maximum value reached 0.375.Acidithiobacillus ferrooxidans accounted for the highest proportion throughout the bioleaching process,and that of sample in the presence of 5 g·L^(−) AWF reached 28.63%.The results should show reference to application of agricultural wastes and low grade copper sulfide ores.

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%.

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.

Bio-leaching of low-grade large porphyry chalcopyrite-containing ore

In order to economically recover the copper from the low grade copper ores, a bioleaching solvent extraction electrowinning plant with a design capacity of 2 000 t cathode copper per year in Dexing Copper Mine was operated in September, 1997. The results during the 10 month period of the industrial copper dump leaching have been obtained and the approaches have been carried out to enhance the copper dissolution from the waste rocks. The overall operation flowsheet is depicted. The problems confronted in the process and possible way for improving are discussed.

Origin of Illites at Dexing Porphyry Copper Deposit, Jiangxi Province, East China: Implications for Alteration Zoning and Ore-Forming Fluid Evolution

According to differences in features of illites including spatial distribution, crystallinity index, volume of swelling layer, polytype and relationship between its index and copper grade, two typical kinds of illite can be classified within the Tongchang porphyry copper deposit, Dexing County, East China. One is a kind of hydrothermally altered minerals within the hydrothermal alteration zone, including altered granodiorite\|porphyry and altered metamorphic tuffaceous phyllite near the contact zone with porphyry rockbody. The illite crystallinity and expandability are mainly affected by water/rock ratio or fluid flux, and hydrothermal illite is formed by illitization of plagioclase and/or micas during hydrothermal fluid evolution within the porphyry body and near the contact zone with wall rocks. The other is a product of low\|grade metamorphism itself by illitization of smectite, whose crystallinity index is lower than the hydrothermal illite and which is of 2M\-1 polytype with no swelling layer, in the altered metamorphic tuffaceous phyllite far from porphyry rockbody (>2 km). Moreover, the negative correlation between illite index and copper grade indicates that, within the alteration zone, the smaller the illite crystallinity, the stronger the alteration degree, and the higher the copper grade due to higher water/rock ratio. At lower levels of the porphyry body, however, the illite crystallinity (IC) values are controlled mainly by temperature and time.

还原熔炼法回收低品位锡中矿中锡资源

本研究采用还原熔炼法回收低品位锡中矿中锡资源,并对氧化铜为添加剂时锡的回收行为进行了探究。结果表明一定条件下,提高熔炼温度、增加焦炭添加量、延长保温时间和增加氧化铜添加量可提高锡回收率;然而温度过高时,渣中铁氧化物被还原为金属铁,并与还原态金属锡发生合金化反应生成熔点较高的Fe-Sn合金,使其在渣金分离过程中易夹带在渣中造成锡损失;熔炼过程添加氧化铜时,其可通过还原反应生成金属铜,继而与金属锡发生合金化反应生成Cu-Sn合金,热力学上降低了产物Sn的活度,促进了锡的还原回收;在焦炭添加量7%、氧化铜添加量5.8%、熔炼温度1 250℃、保温时间150 min条件下,锡回收率可达到95.24%,锡主要分布在Cu-Sn合金(分布比例90.20%)和含锡烟尘(分布比例5.04%)中。本研究实现了低品位锡中矿中锡的高效回收。

内蒙古某铜矿选矿试验研究

内蒙古某铜矿主要含以斑铜矿、辉铜矿为主的次生硫化铜,铜平均品位2.52%。根据该铜矿石的矿石性质特点,进行了铜的原矿粗磨选别-铜粗精矿再磨再选的条件研究,通过对浮选指标各影响因素的优化,得出了适合铜矿石粗选及精选的最佳工艺条件,原矿磨矿细度-0.074 mm、70%的条件下,活化剂Na_(2)CO_(3)+Na_(2)S用量分别为1 000 g/t和300 g/t,组合捕收剂丁基黄药和酯-112分别为150 g/t和110 g/t。再经一次粗选、一次扫选获得铜尾矿,粗选铜精矿再磨后再经三次精选,中矿顺序返回处理后,最终可获得铜品位为25.74%的铜精矿,且铜的回收率达到了87.30%。

云南某低品位铜矿选矿试验研究

低品位铜矿的高效开发利用对于保障铜资源的安全供给意义重大。针对云南某低品位铜矿,通过详细的工艺矿物学研究、浮选关键参数条件试验及全流程闭路试验,分析矿石中铜矿物的赋存状态,并针对性地开发适宜该矿的浮选工艺与药剂制度。结果表明,该矿石原矿含Cu 0.31%,其中硫化铜占比达93.55%,铜矿物主要为黄铜矿,嵌布粒度较细,呈浸染嵌布于脉石矿物中;粗选采用非极性捕收剂CM-3可以在保证铜回收率的前提下显著提升粗精矿品位,同时扫选采用Z-200进行强化浮铜有利于进一步提升铜回收率;实验室闭路试验在磨矿细度为-74μm占72%的条件下,采用一粗二精三扫流程获得了铜品位23.03%、回收率86.97%的铜精矿。研究结果可为国内低品位铜矿的高效浮选回收提供参考与借鉴。

某高硫低品位铜矿浮选试验研究

安徽某高硫低品位铜矿硫品位41.30%、铜品位0.53%,易氧化,选矿指标不稳定。为了改善铜硫分离效果,研究了磨矿细度、药剂种类和药剂用量等对浮选指标的影响。结果表明,磨矿细度-0.074 mm粒级占83.88%,采用一粗二精二扫闭路浮选流程,以CaO+Na_(2)S为组合抑制剂、Z-200为捕收剂、2#油为起泡剂,获得了铜品位15.27%、回收率80.96%的技术指标。试验结果可为高硫低品位铜矿浮选回收铜提供参考。

云南某低品位斑岩型铜矿浮选回收试验研究

云南某大型斑岩型铜矿铜品位0.32%,伴生有钼,具有综合回收价值。采用一次粗选、两次精选、两次扫选工艺流程综合回收矿石中的铜和钼等金属。系统研究工艺参数条件如原矿磨矿细度、粗精矿再磨细度、捕收剂、抑制剂、起泡剂种类及用量等对铜回收的影响,并考察伴生金属钼、金和银的回收情况。结果表明,捕收剂PL307和起泡剂HCLL对铜浮选回收效果好,在原矿磨矿细度-0.075mm占比65%、粗精矿再磨细度-0.045mm占比90%、捕收剂PL-307用量120g/t、抑制剂石灰用量300g/t、起泡剂HCLL用量20g/t的最佳参数条件下,经过闭路试验可获得产率1.23%、铜品位22.84%、铜回收率87.79%的选矿指标,铜精矿产品含钼0.398%、金4.33g/t、银62.50g/,其中钼回收率为71.99%、金回收率为66.57%、银回收率为14.48%,伴生金属钼和金也得到了较好的回收,选别指标好。

某含钼低品位硫化铜矿综合回收钼的选矿研究

针对南美某含钼0.027%、含铜0.45%的低品位铜矿进行了选矿试验研究。应用适宜的浮选药剂,采用铜钼混合浮选-铜钼分离流程,闭路试验获得了铜品位26.93%、铜回收率81.96%的铜精矿和钼品位25.32%、钼回收率76.24%的钼精矿,铜、钼资源得到有效回收。

提升某高硫低铜品位铜硫矿铜浮选回收指标试验研究

安徽铜陵某铜硫矿浮选厂处理的原矿含铜0.34%,其中硫化铜占近93%,含硫31.26%,属于高硫低铜硫化矿。选厂铜回收率长期维持在82%~84%,明显低于原矿中硫化铜理论回收率。为提升该矿石中铜的回收,开展磨矿细度优化以及复合酯类捕收剂强化铜浮选的试验研究。结果表明,在磨矿细度-74μm占75%,使用复合酯类捕收剂的条件下,小型闭路试验获得铜精矿铜品位为16.43%,铜回收率达到94.07%的指标,较现场指标分别提高1个和9个百分点;通过对小试和现场产品的粒级组成深入分析,得出现场磨矿细度不足,磨矿产品粒度组成不均匀是造成铜损失在尾矿的关键原因。同时,小试结果证明使用新型复合酯类捕收剂可强化微细粒铜矿物的回收。为选厂在实际生产中提升指标提供了科学的方向和依据。

某高硫难选铜钼矿浮选工艺优化及工业应用研究

某铜钼矿原矿铜品位0.45%,钼品位0.015%,硫品位2.47%,含金0.12 g/t,是典型的斑岩型铜钼矿。因长期暴露而氧化率逐渐升高,导致目的矿物可浮性变差。原有药剂制度及工艺条件对其适应性较差,生产指标不理想。针对该难选矿石开展了实验室工艺优化试验研究,制定了"铜钼快速浮选-铜硫混合浮选再分离"的工艺流程,工业试验结果相比优化前铜回收率提高了0.60个百分点,钼回收率提高了5.33个百分点。

低品位氧化铜钴矿堆浸试验研究

对刚果(金)某低品位氧化铜钴矿资源进行了堆浸试验研究,考察了喷淋强度、喷淋酸度和矿石粒度对铜钴浸出率的影响。结果表明,喷淋酸度和喷淋强度对铜钴浸出速度和累计浸出率影响显著,而矿石粒度对浸出过程影响不大。确定了低品位氧化铜钴矿适宜的堆浸条件为:喷淋酸度20 g/L,喷淋强度15 L/(m^(2)·h),矿石粒度-40 mm。在此条件下,堆浸100 d,铜和钴累计浸出率分别可达90.89%和82.27%。

国外某低铜锌高硫复杂金银矿选冶综合回收试验研究

针对国外某金银矿中黄铁矿含量高、铜锌品位低(Cu 0.11%、Zn 0.22%)、部分金以硫化矿粒间金及裂隙金赋存,银矿物种类多而杂的特点,采用“尼尔森重选-铜优先浮选-全硫混浮抛尾-全硫精矿细磨浸出-氰化尾渣选锌”的选冶联合新工艺,实现了该矿中金、银矿物的绿色分类快速提取和伴生低品位铜、锌矿物的高效综合回收。选冶全流程试验获得总回收率:Au 91.0%、Ag 77.3%、Cu 77.5%、Zn 63.2%,其中重选金银精矿含Au 41523.71 g/t、Ag 13763.36 g/t,铜精矿中含Au 400.8 g/t、Ag 5429.00 g/t、Cu 21.19%,锌精矿中含Zn 35.14%,全硫混浮尾矿(抛废)产率为74.6%。

广东某硫化铜矿石工艺矿物学及分选工艺研究

为了提高广东某低品位硫化铜多金属矿中铜以及共伴生硫、铁的资源利用率,采用化学多元素分析、矿物自动分析仪等手段进行了系统的工艺矿物学研究。结果表明,矿石中Cu、S、Fe的含量分别为0.50%,27.68%,34.07%。黄铜矿为铜的主要赋存矿物,其他含铜矿物有铜蓝、辉铜矿等。针对铜硫分离困难的问题,提出采用半自磨—球磨—铜浮选—磁黄铁矿磁选—硫浮选的流程,可以获得铜精矿铜品位为16%,回收率为70%,磁选后磁黄铁矿精矿硫品位为30%,回收率为36%,硫精矿硫品位为40%,回收率为45%的结果,获得了较好的铜硫分离效果。