Effect of temperature on leaching behavior of copper minerals with different occurrence states in complex copper oxide ores

The effect of temperature on leaching behavior of copper minerals with different occurrence states in complex copper oxide ores was carried out by phase analysis means of XRD, optical microscopy and SEM-EDS. The results indicated that at ambient temperature, the easily leached copper oxide minerals were completely dissolved, while the bonded copper minerals were insoluble. At lukewarm temperature of 40℃, it was mainly the dissolution of copper in isomorphism state. With increasing temperature to 60℃, the copper leaching rate in the adsorbed state was significantly accelerated. In addition, when the temperature increased to 80℃, the isomorphic copper was completely leached, leaving 11.2% adsorbed copper un-leached. However, the copper in feldspar-quartz-copper-iron colloid state was not dissolved throughout the leaching process. Overall, the leaching rates of copper in different copper minerals decreased in the order: malachite, pseudo-malachite > chrysocolla > copper-bearing chlorite > copper-bearing muscovite > copper-bearing biotite > copper-bearing limonite > feldspar-quartz-copper-iron colloid.

Copper hydrometallurgy—current status, preliminary economics, future direction and positioning versus smelting

The heap leaching of oxide copper ores with copper cathode recovery by solvent extraction and electro-winning is now well established as a low-cost method of copper recovery. This technology has recently been applied successfully to mixed oxide and chalcocite ores, notably in Chile at Cerro Colorado, Quebrada Blanca and Zaldivar. Currently, there are significant development efforts underway to try to extend heap leaching to chalcopyrite ores. The success of heap leaching/SX/EW has also led to a revival in the development of hydrometallurgical processes to recover copper from chalcopyrite and other copper concentrates. The current status of copper hydrometallurgy is reviewed and the most commercially attractive potential applications are explored. The advantages and disadvantages of the hydrometallurgical treatment of chalcopyrite concentrates and its preliminary economics are compared with those for the current best practices in copper smelting and refining.

Technological conditions and kinetics of leaching copper from complex copper oxide ore

The kinetic behavior of leaching copper from low grade copper oxide ore was investigated. The effects of leaching temperature, H2SO4 concentration, particle size of crude ore and agitation rate on the leaching efficiency of copper were also evaluated. And the kinetic equations of the leaching process were obtained. The results show that the leaching process can be described with a reaction model of shrinking core. The reaction can be divided into three stages. The first stage is the dissolution of free copper oxide and copper oxide wrapped by hematite-limonite ore. At this stage, the leaching efficiency is very fast （leaching efficiency is larger than 60%）. The second stage is the leaching of diffiuent copper oxides, whose apparent activation energy is 43.26 kJ/mol. During this process, the chemical reaction is the control step, and the reaction order of H2SO4 is 0.433 84. The third stage is the leaching of copper oxide wrapped by hematite-limonite and silicate ore with apparent activation energy of 16.08 kJ/mol, which belongs to the mixed control.

Mechanochemical sulfidization of a mixed oxide-sulphide copper ore by co-grinding with sulfur and its effect on the flotation efficiency

Mechanochemical sulfidization of a mixed sulfide/oxide copper ore by co-grinding with sulfur and additives including Mg(NO3)2 and Fe(NO3)3 salts and iron,aluminum and magnesium powders was investigated for the first time.Also,the influence of sulfidization during the wet-milling process was examined on the separation efficiency and recovery of copper in detail.The results demonstrated that co-grinding with sulfur solely had the best flotation performance at the value of 0.5 wt.%and it was attributed to the possible existence of S\\O bonding on copper oxides surfaces.In addition,adding magnesium nitrate salt,magnesium powder,iron nitrate salt and aluminum powder as additive associated with 0.5 wt%sulfur into ball milling caused the flotation improvement at the amounts of 0.2 wt%,0.2 wt%,0.5 wt%and 0.5 wt%,respectively.Also,the effect of grinding time and sulfidization pH with 0.5 wt%sulfur solely was determined and pH s of 7.5 to 8.5 gave the best results.The highest recovery(75.76%)and separation efficiency(63.44%)were achieved at pH of 7.5 and 8.5,respectively.

Techniques of copper recovery from Mexican copper oxide ore

Mexican copper ore is a mixed ore containing mainly copper oxide and some copper sulfide that responds well to flotation. The joint techniques of flotation and leaching were studied. The results indicate that an ore containing 19.01% copper could be obtained at a recovery ratio of 35.02% by using sodium sulfide and butyl xanthate flotation. Over 83.33% of the copper oxide can be recovered from the railings by leaching in suitable conditions, such as 1 h stirring at a temperature around 25 ℃with a mixing speed of S00 r/min, an H2SO4 concentration of 1.0 mol/L and a mass ratio of the ore-slurry-liquid to solid （mL/ms） of 3. The overall yield of refined ore after flotation and leaching is over 89.18% of the copper, which is much better than sole flotation or leaching. A copper product containing more than 99.9% copper was obtained by using the process： flotation-agitation leaching- solvent extraction-electro-winning.

Recovery prediction of copper oxide ore column leaching by hybrid neural genetic algorithm

The artificial neural network(ANN)and hybrid of artificial neural network and genetic algorithm(GANN)were appliedto predict the optimized conditions of column leaching of copper oxide ore with relations of input and output data.The leachingexperiments were performed in three columns with the heights of2,4and6m and in particle size of<25.4and<50.8mm.Theeffects of different operating parameters such as column height,particle size,acid flow rate and leaching time were studied tooptimize the conditions to achieve the maximum recovery of copper using column leaching in pilot scale.It was found that therecovery increased with increasing the acid flow rate and leaching time and decreasing particle size and column height.Theefficiency of GANN and ANN algorithms was compared with each other.The results showed that GANN is more efficient than ANNin predicting copper recovery.The proposed model can be used to predict the Cu recovery with a reasonable error.

Bioleaching of copper oxide ore by P seudomonas aeruginosa

Bioleaching is an environmentally friendly method for extraction of metal from ores. In this study, bioleaching of copper oxide ore by Pseudomonas aeruginosa was investigated. Pseudomonas aeruginosa is a heterotrophic bactermm that can produce various organic acids in an appropriate culture medium, and these acids can operate as leaching agents. The parameters, such as particle size, glucose percentage in the culture medium, bioleaching time, and solid/liquid ratio were optimized. Optimum bioleaching conditions were found as follows： particle size of 150-177 μm, glucose percentage of 6%, bioleaching time of 8 d, and solid/liquid ratio of 1：80. Under these conditions, 53% of copper was extracted.

SYNERGISTIC ACTIVATION OF CHELATING AGENT ON XANTHATE DURING THE FLOTATION OF REFRACTORY COPPER OXIDIZED ORES

For realizing the effective flotation of refractory copper ox-idized ores and developing the activation-flotation theory , the influences of nine different organic chelating agents on xanthate collection pcnver and its adsorption characteristics ivere studied in the flotation of malachite and chrysocolla representatively selected by means of XPS,IR, absorbed quanti-ty measurements and flotation tests.For easily-dissolved malachite flotation , a small amount of chelating agent can obviously enhance xanthate collecting power and make malachite floated easily , and so reduces the consumption of xanthate. For hard-dis-晄olved chrysocolla, chelating agent is able to increase its recovery to 90% , but the chelating agent consumption is high. Chelating agent and xanthate can produce synergistic adsorptions, which follmv Freundlich's adsorption equation on malachite and Chrysocolla surfaces. The high chemical activity of chelating agent and its synergistic activation on xanthate are the key to improving xanthate collection poiver. The synergistic activation of chelat-ing agent on xanthate on melachite surfaces is clearly stronger than on chrysocolla surfaces. According to experimental results, it can be thought that the synergistic activation results from the synergistic complexation of chelating agent and xanthate with copper ions to form biligand-tribasic co-ordination complex.

Effect of Desliming on Flotation Response of Kansanshi Mixed Copper Ore

The Kansanshi mixed copper sulfide-oxide ore contains significant proportions of fine material manifesting in a variety of processing challenges. This paper presents the work which was carried out to evaluate the efficacy of desliming in improving the flotation response of the ore. Two modes of desliming were investigated, namely;sieving and elutriation after which the deslimed material was subjected to Kansanshi standard laboratory flotation conditions. The minimum copper feed grade for the mixed copper ore was 0.5% Total Copper (TCu). The outcome of this work has shown that desliming improves the flotation response of the Kansanshi mixed copper ore. At a rougher copper concentrate grade of 8%, copper metal recoveries obtained with desliming were in excess of 70% compared to 58% achieved with baseline tests without desliming. It was further observed that desliming resulted in improved flotation rates for the sulfide minerals. For a flotation time of 3 minutes, recoveries of 69% and 74% were obtained with elutriation and sieving respectively compared to 58% recovery for baseline tests. From the same results it was also evident that, of the two modes of desliming investigated, sieving yielded better performance than elutriation.

刚果(金)绿纱铜钴矿湿法冶金工艺优化

绿纱铜钴矿位于刚果(金)上加丹加省卢本巴西市西北方向约70km。绿纱铜钴矿床以硫化矿为主,近地表有部分氧化矿。设计采用氧化矿和硫化矿混合浮选后沸腾焙烧,焙砂进入浸出-萃取-电积生产阴极铜,萃余液中和生产氢氧化钴的湿法冶金工序。实践表明,采用混合浮选影响铜钴的综合回收,且设备产能无法充分发挥。改造后,采用氧化矿直接浸出,硫化矿浮选-焙烧后进入湿法系统的方案,铜综合回收率大幅提升,且产能由2.5万吨/年,增加到3.5万吨/年。

刚果(金)某氧化铜矿选矿工艺试验研究

刚果金某高酸耗氧化铜矿,Cu 1.54%,Co 0.028%,S 0.12%,氧化率87%。原矿湿法冶金直接浸出酸耗较高,吨铜酸耗达15.29t/tCu。通过浮磁联合工艺试验研究,提高湿法冶金给料品位,选出硫化矿和氧化矿分别进行焙烧浸出和直接浸出,降低湿法冶金吨铜酸耗。高酸耗铜矿经过先浮选硫化矿、再硫化浮选氧化矿,浮选尾矿进行磁选的浮磁联合工艺流程,铜金属综合回收率79.29%。其中硫化精矿Cu 21.17%,回收率13.54%,氧化精矿Cu 2.74%,回收率60.49%,磁选精矿Cu 3.49%,回收率5.26%。将硫化精矿与磁选精矿、氧化精矿产品分别进行焙烧浸出和直接浸出,吨铜酸耗分别为0.38、7.58、5.62t/tCu,相比原矿直接浸出,吨铜酸耗下降明显。

云南楚雄难处理氧化铜矿酸浸试验研究

根据云南楚雄某氧化铜矿原矿品位低、矿石性质复杂、氧化率高、结合率高、钙镁等碱性脉石含量高的特点,进行了选冶联合试验研究。酸浸之前采用高效捕收剂OA反浮选脱除绝大部分碱性脉石矿物,然后采用硫酸用量为150kg/t,液固比为2∶1,浸出时间为30min的浸出工艺条件,最终可获得铜浸出率为84.6%的良好指标,为难处理氧化铜矿的分选提供了一条新途径。

湿法(催化氧化法)炼铜工艺研究

提出了一种催化氧化酸浸硫化铜矿的湿法冶炼方法。采用纯氧作氧化剂,找到了一种新型催化剂,降低了反应温度,缩短了反应时间,在密闭条件下,通过两步反应,利用中间脱硫方法,解决硫磺包膜阻碍反应速度问题,最终制得海绵铜,副产硫酸亚铁及硫磺(在得到硫磺的基础上进而制备硫化钠)。考察了反应温度、固体质量与液体体积之比、氯离子浓度、反应时间对铜浸出率的影响。研究结果表明,在适宜的工艺条件下,铜的浸出率达到了98%以上。采用闭路循环,充分利用了资源,并且克服了火法炼铜中副产二氧化硫污染环境的缺点,污染小,体现了环保意识,为硫化铜矿的湿法冶炼开辟了一条新途径。

从湿法炼锌净液渣中回收铜的新工艺研究

研究了以湿法炼锌净液渣生产阴极铜,考察了稀硫酸浸出锌、氧化浸出铜、不溶阳极电沉积工艺条件。试验结果表明:在适宜条件下,锌浸出率达98.69%,镉浸出率96.15%,钴浸出率达70.70%;进入电积系统的铜的直收率为80.69%,电积过程铜回收率为99.68%,铜总回收率大于99%;阴极铜质量达到国家1#阴极铜(GB/T467—2010)标准。

由海绵铜制备高纯超微CuO粉末的研究

用空气催化氧化，氨—碳酸铵分步浸出海绵铜，并且由浸出液的滤液直接水解来制备高纯超微ＣｕＯ的工艺。

湿法炼锌净化钴镍渣综合回收产铅渣工艺优化

某冶炼厂湿法炼锌净化工序存在铅渣含锌量和含镉量高、铅品位低的问题,主要原因是净化工序所采用的合金锌粉粒度较粗,一段净化除镉效率低,钴在系统中富集,以及钴镍渣浸出率低。针对上述问题,对净化钴镍渣工序进行了优化:增加合金锌粉筛分工序,将原一段净化一次除铜镉工序改为二次除铜镉工艺,对钴镍渣进行高温高酸多次浸出,将高钴渣与电解锌阳极泥进行联合氧化浸出,以及增加铅渣水洗工序。工艺优化后,钴镍渣综合回收所产铅渣量减少了60%以上,铅品位达到35%以上,含锌量降至10%左右,锌回收率达到了91%以上。采用该工艺技术综合回收有价金属,效益显著,实现了节能减排、环境友好的目的。

从铜镉渣中提取海绵镉的试验研究

锌粉置换过程是处理铜镉渣提取海绵镉的重要环节。对铜镉渣提取海绵镉原理及生产工艺进行了简单介绍,对锌粉置换过程中置换温度、锌粉用量、置换时间、搅拌强度进行了试验探索。研究表明,置换温度50℃、锌粉用量为理论用量的1.2倍、搅拌速率为80 r/min、置换时间20 min、澄清时间40min的条件下,海绵镉的品位可达到78.7%。采用多点加入锌粉的方式,可以减少海绵镉夹杂现象,提高海绵镉的品位。

硫酸浸出处理铜锌废渣生产氧化锌

用硫酸浸出——置换——净化法分离回收铜锌废渣中的铜锌,产出海绵铜和氧化锌。铜、锌的漫出率分别达到98.99%和99.50%,铜、锌的回收率均达97%以上。工艺条件较易控制,产品海绵铜品位大于75%,氧化锌达到二级标准。

压缩空气—氨浸法生产氧化铜工艺在广兴化工厂的应用

直接向Cu—NH3 —CO2 -3 体系中以压缩空气方式供氧 ,能将体系中单质铜转变成 [Cu(NH3 ) 4]2 + 形式 ,经过蒸氨得到氧化铜。该工艺成本低 ,回收率高 ,工艺简单。

氧气酸浸法处理硫化铜矿制取海绵铜

采用氧气湿法酸浸技术对内蒙霍格旗低品位难选硫化铜矿进行了浸铜试验,以纯氧作氧化剂,氯离子为催化剂,在密闭条件下,硫酸浸出Cu2+,经铁屑还原制备出海绵铜。考察了矿石粒度、酸用量、固液比、温度、三氯化用铁量对铜浸出率的影响,确定了最佳浸出工艺条件,在最佳浸出工艺条件下,铜的浸出率达到98%;浸出液除杂后,采用还原铁粉置换,考察了置换时间、pH、温度和还原铁粉用量对铜单质生成的影响,在最佳置换工艺条件下,制备出的海绵铜含量为80.1%。工艺采用闭路循环,可充分利用资源,反应时间缩短,反应温度降低,且克服了火法炼铜中二氧化硫对环境的污染,为硫化铜矿的湿法冶炼开辟了一条新途径。