Copper Oxide Ore Research Articles

Investigation of Copper Recovery rate from Copper Oxide Ore Occurring as Coarse Grains Locked in a Porphyritic Fine Grain Alumina and Silica

An investigation was carried out on a high grade copper oxide ore to determine the optimum recovery rate of copper from the pregnant leached solution obtained from leaching the ore in a sulfuric acid lixiviant. The copper oxide ore occur in coarse grains locked in a porphyritic fine grain alumina and silica. 800 g of copper oxide ore was obtained at the deposit; the samples were chemically and mineralogically analyzed. The analysis shows that the copper oxide ore contain 19.52 % copper extraction. The ore samples were crushed to sizes within 5 cm and 12 cm. The crushed samples were then grinded to a mesh size of -150 µm. This size was used to conduct the leaching process and sulfuric acid was used as the lixiviant. Parameters varied in this study include: the concentration of acid, temperature and time. The pregnant leach solution obtained was analyzed and the results showed an increase in the % recovery of copper as the molar concentration of H2SO4 increases from 0.25M to 1M and the % copper extraction decreases as the acid concentration increases from 1 M to 3 M. Higher copper recovery of 32.13 % was observed at elevated temperature of up to 80oC. These findings suggest the possibility of effectively producing copper from the Pingel-Bauchi Deposit through hydrometallurgical extraction process; optimum recovery can be obtained at an elevated temperature using acid concentration of 1 M.

Investigations on Bioleaching of Copper and Zinc Oxide Ores

Although bioleaching is a well-known process for extraction of metals from sulfide ores investigated by many researchers, bioleaching of oxide ores has not been thoroughly studied. In this study, bioleaching of copper oxide ore and zinc oxide ore has been carried out by a heterotrophic bacterium, Pseudomonas aeruginosa. Organic reagents that are produced during bioleaching serve as a leaching agent and dissolve copper and zinc from these ores. In these experiments, the effect of parameters like bioleaching time, glucose percentage in the culture medium and solid/liquid ratio was optimized. Optimum conditions were found as glucose percentage of 6 (both copper and zinc), bioleaching time of 8 days for copper and 5 days for zinc, and the solid/liquid ratio of 1:100 for both zinc and copper. Under these conditions, 47% of copper and 41% of zinc were extracted. According to the obtained results, tolerance of this bacterium to copper is more than zinc tolerance.

A Review of Lanthanum Nanoparticles Impregnated Compound Arsenic Fixation Behaviour in Copper Aqueous Solution

Mining is a strategic sector of the global economy. However, the effects of mining and mineral processing activities on human health and environment cannot be overemphasized. The prevailing areas of concern include: air quality, water quality, water quantity and the ecological impacts of these activities. Mines activities bring about the release of used water into the environment, nearby rivers or into the ground. Streams, wells and lakes surrounding the mines and the underground water are affected by these mining and mineral processing activities. Arsenic is a major trace impurity that contaminates the air and water surrounding copper mines as a result of the various activities of mining and mineral processing. It therefore poses a worrisome threat to human health and sustainability of the environment. The use of lanthanum nanoparticles impregnated compound has been identified as an effective adsorption technique for the immobilization of arsenic from numerous aqueous solutions. The leaching behaviour of copper and arsenic were analyzed in this review to provide a knowledge on the behaviour of different adsorbents such as lanthanum nanoparticles impregnated compounds during the adsorption reactions. Lanthanum compounds have been applied in the arsenic fixation of different aqueous solutions in previous studies. Lanthanum nanoparticles impregnated compound changes the valence state of arsenic in aqueous solution and the establishment of the ability of the lanthanum nanoparticles impregnated compound to change the valence state of arsenic in aqueous solution suggest the possibility of successfully applying it in the arsenic fixation of hydrometallurgical processing of copper oxide and copper carbonate ores.

Solvent extraction of copper from an industrial sulfate liquor using Chemorex CP-150

The extraction behavior of Cu(II) ions from a real sulfate liquor obtained from the heap leaching stage of a copper oxide ore was investigated using a chelating reagent, Chemorex CP-150 in kerosene. A comparative study was also carried out on the extraction capability of Cu(II) ions using other solvents including D2EHPA and Cyanex 272.Chemorex CP-150 demonstrated an effective and selective extraction performance of copper with the amount of extracted Fe less than 15%. Also the results obtained indicated that more than 66.4% and 96.99% of Cu were transferred to the organic phase in a single extraction stage using 15% (v/v) Chemorex CP-150 at the A:O phase ratios of 1:1 and 1:4, respectively. In addition, the McCabe-Thiele diagram exhibited that two extraction stages were required to achieve the maximum amount of Cu at a 1:1 phase ratio under the optimal conditions (25 °C, pH 2.5, and 20 min contact time). Also, thermodynamic data proved that the extraction process was slightly endothermic (ΔH = 7.62 kJ/mol), indicating the relatively smaller heat effects on the formation of a single complex species (CuR2). Stripping of copper from the loaded organic phase was also conducted, and it was found that ~99.38% copper could be recovered using 165 g/L H2SO4 at a 2:1 A:O phase ratio after 5 minutes stripping.

Processing of oxidized copper ores and sulfide copper concentrates of the Actogay deposit by pyrometallurgical methods

This work is devoted to the investigation of the possibilities of processing oxidized copper ore and sulfide copper concentrate of the Aktogay deposit by pyrometallurgical methods at the operating metallurgical units of the largest copper producer in Kazakhstan, Kazakhmys Smelting Ltd. The chemical, phase compositions and thermal properties of the samples of the Aktogay ore and concentrate were investigated. To test the possibility of using oxidized copper ore of the Aktogay deposit as quartz flux for autogenous smelting in Vanyukov furnaces (VF) with copper sulphide concentrates laboratory experiments were carried out. They made it possible to establish that the replacement of quartz flux on the oxidized ore of the Aktogay deposit is entirely permissible in consideration of the satisfactory composition of slags and mattes obtained in the smelting, even when the content of silica in the ore is 64.56 %. With a higher content of silica in the ore, its use as a flux will be even more effective. The available capacities of the two Vanyukov furnaces are not sufficient for processing all available high-sulfur raw materials, including the Aktogay sulphide copper concentrate, using autogenous melting. Therefore, in the laboratory and in an industrial scale, a preliminary test was carried out on the possibility of processing a part of the copper poor and high-sulfur Aktogay concentrates on the electric furnaces of the Zhezkazgan Copper Smelting Plant (ZCS). The results of laboratory studies and preliminary industrial tests have shown the possibility of such processing with the production of mattes containing no less than 47 % of copper and suitable for converting on existing equipment of ZCS.

A New Technique for Recovering Copper From Complex Copper Oxide Ore by Flotation and Metallurgical Processing

Copper oxide ore has a complex composition, and a low recovery rate is often achieved via the traditional sorting method. A new combined process of flotation–high-gradient magnetic separation–leaching is proposed here to recover copper minerals. The test results showed that the flotation process was successful when using sodium sulfide as a vulcanizing agent and butyl xanthate as a collector. The flotation concentrates can be qualified with a copper grade of 29.37% and a recovery rate of 32.22%. Flotation tailings separated by high-gradient magnetic separation can yield two products, namely, magnetic separation concentrates and magnetic separation tailings, via the leaching recovery of the remaining copper minerals. However, the leaching conditions are different. The leaching rates of copper from magnetic separation concentrates and tailings are 28.44% and 26.95%, respectively. The total copper recovery is 87.61%. This new technology introduces a high-gradient magnetic separation process, which achieves the requirements of low energy consumption and high-efficiency copper recovery.

Influence of seawater and discard brine on the dissolution of copper ore and copper concentrate

It is well known that the Chilean mining industry is facing a shortage of water resources for the sustainable operation not only of existing plants but also of future projects. In addition, the depletion of oxide ores and those containing secondary sulfide copper will leave chalcopyrite ores as the main source of copper for future plants. To assure a sustainable hydrometallurgy plant, alternative water resources such as seawater and discard brine from desalination plants should be used together with a leaching process that can enhance the dissolution of chalcopyrite. This paper reports a study on the dissolution kinetics of finely ground copper oxide ore, chalcopyrite ore, and chalcopyrite concentrate leached in shake flasks, agitated reactors and columns using seawater and discard brine as the leaching solution. The type of chloride solution did not affect the dissolution of the copper oxide mineral. Regardless of the chloride solution used in the leaching test stirred at room temperature, the chalcopyrite dissolution did not exceed 4%, but increased to 90% when the temperature was increased to 50 °C. Column leaching of chalcopyrite ore with a P80 of 5 mm achieved a maximum dissolution of 43% of copper using discard brine at ambient temperature. The results show that curing time of the packed bed before the commencement of column irrigation and intermittent irrigation during leaching appeared to be important parameters to enhance dissolution of copper. Less irrigation time and more resting time can be beneficial for an industrial-scale heap leach plant.

A comprehensive study of the leaching behavior and dissolution kinetics of copper oxide ore in sulfuric acid lixiviant

The leaching behavior of an Iranian copper oxide ore in sulphuric acid was investigated in detail to evaluate the influence of various factors, to optimize the dissolution conditions and to determine the kinetics of the leaching. The results indicated that the increase in the leaching time and temperature enhanced the leaching rate of copper. The leaching rate increased up to a certain value with increasing the agitation rate, acid concentration and liquid/solid ratio and with further increment reduced. Agitaion rate had the most influence on the dissolution of copper. The 3D response surface graphs confirmed the interactive effects of sulphuric acid concentration, agitation speed, and liquid/solid ratio with temperature. About 91% copper content was leached at~13% sulphuric acid concentration, stirring rate of 600 rpm, liquid/solid ratio of 10 mL/g and 50 °C after 80 min leaching. The dissolution kinetics was examined according to heterogeneous models. The shrinking core model assuming rate control by diffusion through the product layer was found appropriate to describe the dissolution of copper in sulphuric acid solution. The activation energy was obtained to be 26.699 kJ/mol and equation representing the leaching kinetics of copper based on diffusion-controlled model was found to be 1-3(1-x)2/3+2(1-x) = 161.97×exp(-26.699×103/8.314×T)×t.

Structural modification of cellulose to enhance the flotation efficiency of fine copper oxide ore

Structural modification of cellulose to enhance the flotation efficiency of fine copper oxide ore

Copper Oxide Ore Leaching Ability and Cementation Behavior, Mesgaran Deposit in IRAN

One of the Iranian copper deposits that is located east of Iran and also known as a primeval one in that area is Mesgaran Field. Old mining works have been clearly seen in the area. Iran is located on global copper belt and as a result it has numerous potential areas as copper deposits. The purpose of this study is identifying possible potentialities of copper mining in less developed regions of Iran with basic modern technologies. In this study, laboratory investigations of this field were done on samples via leaching and the cementation method. According to the study purposes, acid concentration, temperature, time and pulp density were selected as the main factors that were tested in leaching studies. Moreover, pH, temperature, time and the amount of iron powder were factors which were tested for copper cementation. Optimum conditions of leaching studies with 99.11% recovery rate were obtained after 120 grams per liter of H2SO4, 80 degrees Celsius, 2 hours and 100 grams per liter of solid to liquid. On the other hand, optimum conditions of cementation by iron powder were resulted at more than 95% with a pH of 3, 45 degrees Celsius, 1 hour and 1.5 times more than the stoichiometric equation of required iron powder amount to precipitate copper.

Experimental study of sulfuric acid effects on hydro-mechanical properties of oxide copper heap soils

Several mechanisms contribute to changes in the performance of oxide copper heaps. These include physical, biological, chemical and thermal interactions between sulfuric acid and the formation of soil particles. A series of experimental studies was conducted by simulating the column leaching process in the laboratory. The leaching of selected gravel and crushed copper oxide ores from two copper mines was carried out to measure their permeability and strength. The influence of effective parameters on gravel clogging was studied and the clogging coefficient was estimated with time. Furthermore, the ratio of particle reduction (RPR) caused by acid seepage was evaluated and an equation for the internal friction angle of ore particles over time was generated. The present study shows significant reductions of gravel permeability (28% after five months leaching) and friction angle of ore particles (25% after eight months leaching). The effects of sulfuric acid flow on the hydro-mechanical properties of oxide copper heap soils could enhance the accuracy of slope stability design and drainage layers design in industrial heap leaching systems.

Use of high-resolution X-ray computed tomography and 3D image analysis to quantify mineral dissemination and pore space in oxide copper ore particles

Mineral dissemination and pore space distribution in ore particles are important features that influence heap leaching performance. To quantify the mineral dissemination and pore space distribution of an ore particle, a cylindrical copper oxide ore sample (ϕ4.6 mm × 5.6 mm) was scanned using high-resolution X-ray computed tomography (HRXCT), a nondestructive imaging technology, at a spatial resolution of 4.85 μm. Combined with three-dimensional (3D) image analysis techniques, the main mineral phases and pore space were segmented and the volume fraction of each phase was calculated. In addition, the mass fraction of each mineral phase was estimated and the result was validated with that obtained using traditional techniques. Furthermore, the pore phase features, including the pore size distribution, pore surface area, pore fractal dimension, pore centerline, and the pore connectivity, were investigated quantitatively. The pore space analysis results indicate that the pore size distribution closely fits a log-normal distribution and that the pore space morphology is complicated, with a large surface area and low connectivity. This study demonstrates that the combination of HRXCT and 3D image analysis is an effective tool for acquiring 3D mineralogical and pore structural data.

Application of Mathematical Modeling on Copper Recovery Optimization of Oxide Ores

In this study, a mathematical modeling method was used to predict the optimum conditions of column leaching of copper oxide ore. Important parameters such as column height (m), particle sizes (m), acid rate (kg/ton) and leaching time (day) were studied and their impacts on copper recovery were investigated. Experiments were performed on samples with particle size distributions of −25.4 mm and −50.8 mm in six columns with the heights of 2 m, 4 m and 6 m. The results showed that the copper recovery has an inverse relation with column height and particle sizes, and direct relation with leaching time and acid rate. According to the results, the mathematical models based on the macro model predict the copper recovery based on operation conditions. The obtained values of determination coefficient (0.97), root mean square error (2.86) and relative error (0.089) testing datasets, showed the capability of the model in predicting the copper recovery.

Copper Recovery from Yulong Complex Copper Oxide Ore by Flotation and Magnetic Separation

A combined process of flotation and high-gradient magnetic separation was proposed to utilize Yulong complex copper oxide ore. The effects of particle size, activators, Na2S dosage, LA (a mixture of ammonium sulfate and ethylenediamine) dosage, activating time, collectors, COC (a combination collector of modified hydroxyl oxime acid and xanthate) dosage, and magnetic intensity on the copper recovery were investigated. The results showed that 74.08% Cu was recovered by flotation, while the average grade of the copper concentrates was 21.68%. Another 17.34% Cu was further recovered from the flotation tailing by magnetic separation at 0.8 T. The cumulative recovery of copper reached 91.42%. The modifier LA played a positive role in facilitating the sulfidation of copper oxide with Na2S, and the combined collector COC was better than other collectors for the copper flotation. This technology has been successfully applied to industrial production, and the results are consistent with the laboratory data.

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 applied to predict the optimized conditions of column leaching of copper oxide ore with relations of input and output data. The leaching experiments were performed in three columns with the heights of 2, 4 and 6 m and in particle size of <25.4 and <50.8 mm. The effects of different operating parameters such as column height, particle size, acid flow rate and leaching time were studied to optimize the conditions to achieve the maximum recovery of copper using column leaching in pilot scale. It was found that the recovery increased with increasing the acid flow rate and leaching time and decreasing particle size and column height. The efficiency of GANN and ANN algorithms was compared with each other. The results showed that GANN is more efficient than ANN in predicting copper recovery. The proposed model can be used to predict the Cu recovery with a reasonable error.

The potential of stable Cu isotopes for the identification of Bronze Age ore mineral sources from Cyprus and Faynan: results from Uluburun and Khirbat Hamra Ifdan

Copper isotope ratios differ between hypogene sulfidic, supergene sulfidic and oxidized ore sources. Traditional lead isotope signatures of ancient metals are specific to deposits, while Cu isotope signatures are specific to the types of ore minerals used for metal production in ancient times. Two methodological case studies are presented: First, the mining district of Faynan (Jordan) was investigated. Here, mainly oxidized copper ores occur in the deposits. The production of copper from Fayan’s ore sources is confirmed by the measurement of the Cu isotope signature of ingots from the Early Bronze Age metal workshop from Khirbat Hamra Ifdan. Based on our results illustrating differences in the Cu isotope composition between the ore mineralizations from Timna (Israel) and Faynan, it is now possible to determine these prehistoric mining districts from which copper artifacts originated by combining trace elements and Pb isotopes with Cu isotopes. The second case study presents data on Late Bronze Age copper production in Cyprus. Oxhide ingots from the shipwreck of Uluburun (Turkey) were tested for their lead isotope signatures and assigned to Cypriot deposits in the recent decades. The oxhide ingots from Uluburun show a Cu isotope signature which we also found for oxidized copper ores from Cyprus, while younger oxhide ingots as well as metallurgical slag from the Cypriot settlements Kition and Enkomi show a different signature which might be due to the use of sulfidic ore sources from a greater depth of deposits. We assert that there could be a chronological shift from oxidized to sulfidic ore sources for the copper production in Cyprus, requiring different technologies. Therefore, Cu isotopes can be used as a proxy to reconstruct mining and induced smelting activities in ancient times.

Leaching of malachite using 5-sulfosalicylic acid

Abstract In this study, an attractive organic complexation reaction reagent with copper ions was developed for copper leaching from copper oxide ores. The possible chemical reactions of 5-sulfosalicylic acid (5-SSA) in the malachite aqueous solution were determined. Moreover, the influences of various factors, such as time, stirring speed, temperature, reagent concentration and particle size, on the leaching of copper oxide ore were investigated to establish the reaction kinetics. Results show that 5-SSA not only provided an acidic medium but also served as a complexation reaction reagent with copper ions in the solution; thus, 5-SSA exhibited a novel leaching effect on copper oxide ores. The influence of temperature, reagent concentration and ore particle size on the leaching rate of copper was significant. The reaction kinetic equation associated with these major factors was constructed as 1−(1− x ) −1/3 =[0.0021 ( C ) 0.638 ( P ) 0.765 exp(−5103 T )] t , with the reaction activation energy of 42.43 kJ/mol. At the same time, the stirring speed exhibited nearly no effect on the leaching rate of copper, and the dissolution process was controlled by chemical reaction. 5-SSA is therefore a new attractive reagent for copper extraction and can be extended to the metal recovery of other metal oxide ores.

Development metallurgy guidelines for copper heap leach

This paper outlines a comprehensive, cost-effective testing program for the acid-ferric sulfate heap leaching of oxide, supergene and primary copper ores. It is based on extensive experience in copper heap leaching and uses the many technological advances in the field developed over the past several decades. The approach described requires firstly a detailed resource evaluation, then a hydrodynamic characterization of representative samples and, finally, a focused metallurgical testing program. The principles communicated here can be applied to other acid leachable minerals. The program varies considerably from conventional testing in its disciplined, orderly, step-by-step approach, its application of hydrological and chemical principles to leaching, and its reliance on fewer, more tightly controlled column tests. The purpose of the test program is to optimize the financial, time and other resources devoted to the program, while minimizing the financial risks to the development company or companies and the project funding providers.

Sulfidization application during the processing of oxidized copper ores of Udokan deposit

Sulfidization application during the processing of oxidized copper ores of Udokan deposit

Feasibility of bench-scale selective bioflotation of copper oxide minerals using Rhodococcus opacus

Bench-scale selective bioflotation tests were carried out in a 1L Denver cell using Rhodococcus opacus (R. opacus) cells as a collector in malachite–silica binary mixture and copper (Cu) oxide ore systems. Through the first set of tests carried out on the binary mixture, cell concentration and malachite fraction in the feed were optimized, and further the role of shear force by varying impeller speed (800, 1000, and 1200rpm) and adhesive force by varying pH (7 and 11) and ionic strength (1, 100, and 300mM) were examined. Overall, high malachite selectivity was observed under optimized conditions (both recovery and grade>90%). In addition, the recovery and grade of malachite were very sensitive to pH changes, with greater values being obtained at pH7, whereas the impeller speed and the ionic strength did not seem to play a big role over the range tested. The trend was in qualitative agreement with classical Derjaguin-Landau-Verwey-Overbeek (DLVO) interaction energy profiles, which show the relative magnitudes of the adhesive forces between the mineral and the attached cell under equal hydrodynamic conditions. The second set of tests was conducted using Cu oxide ores with two different particle sizes (74–150μm and −74μm) under the optimized conditions determined from the first set of tests. The recovery and grade of malachite were found to be much greater for finer ores (recovery=29.15% and grade=5.17%) than those for coarser ones (recovery=1.34% and grade=3.06%), which is likely due to differences in malachite liberation. Further comparison of the finer ore result with that obtained from the conventional process (i.e., sulfidization followed by xanthate adsorption) indicated that the malachite selectivity of bioflotation is much higher than that of the conventional process (grade=1.43%).