Complex Copper Ore Research Articles

Beyond linear narratives: Complex copper ore exploitation strategies in Early Bronze Age China revealed by geochemical characterization of smelting remains

Despite decades of efforts to reconstruct the bronze production and metal distribution systems of the Shang period in Bronze Age China, there remains limited understanding of the ore choices and smelting practices of the Shang people. This study addresses this research gap by conducting a detailed investigation of Shang period copper ores and smelting remains uncovered at the Tongling site in the Middle Yangtze River valley. The results of lead isotope, copper isotope, trace element, and rare earth element (REE) pattern help to classify the slags from this site into two groups, associated with smelting sulphidic (Group A) and oxidic (Group B) copper ores, respectively. This finding not only serves as the first physical evidence of the use of sulphidic copper ores in Early Bronze Age China but also provides pivotal details of the copper resource exploitation strategies of the Shang people. It challenges the traditional narrative that the Shang people moved to this area solely for the high-grade supergene deposits. The parallel use of both supergene and hypogene ores at the same site complicates the notion of a linear, technological evolution from simpler to more advanced copper sources. Despite the presence of hypogene ores, the study reveals that the Shang people maintained labour-intensive smelting practices, including crushing slag to recover trapped metallic prills, to meet the demands of large-scale bronze casting. This nuanced approach to copper resource exploitation reflects a complex, context-dependent strategy rather than a technological revolution. By highlighting these intricate metallurgical choices, this research contributes to a broader rethinking of early technological development, underscoring the diversity and adaptability of ancient craft industries and their role in shaping Shang society.

Heap leaching of primary and complex copper ore with activation pre-oxidation

Heap leaching of primary and complex copper ore with activation pre-oxidation

Process for Concentration of Low Grade Copper Ore – A Process Design

The paper deals with the results of characterisation and flotation studies carried out on a low grade and complex copper ore sample with a view to design process for its concentration. Flotation studies were carried out under varying conditions of process parameters. Effects of granulometry of the feed, dosage of sodium iso-propyl xanthate as collector, pH and gangue depressant/dispersant were studied. Sulphidization technique and use of potassium octyl hydroxamate as auxiliary collector for flotation of oxidised minerals were observed to enhance copper recovery. Use of sodium silicate as depressant/dispersant for siliceous gangues helped in improving grade of copper concentrate. Rougher followed by multi-stage cleaning were found necessary to produce a high grade copper concentrate. Based on the studies undertaken the process was designed for concentration of the low grade copper ore sample.

Phase transformation and multiphase reaction properties of complex copper ore system under melting conditions

ABSTRACT Copper pyrometallurgical production relies heavily on copper sulphide concentrate as a raw material. The thermal behaviour of key components in complex copper sulphide during heating was investigated in this work. The findings reveal that under a nitrogen atmosphere, the thermal behaviour of natural chalcocite is split into three stages: crystal transformation, loss of water of crystallization, and disintegration of a minor number of components represented by carbonate minerals. In addition to the foregoing thermal behaviour of copper concentrate, S2 is disproportionated at high sulphur partial pressure to form Cu2O in the reaction system where Cu2S, CaO, and S2 coexist. As both are programmed in an oxygen atmosphere, their thermal behaviour is nearly identical. Cu and S combine with O to generate sulphate at temperatures between 400 and 700°C. This sulphate decomposes as an intermediate product as the temperature rises. The paths of primary constituents in the reaction system in the later stages of heating are as follows: S→SO2; Cu2S→CuSO4→CuO·CuSO4→Cu2O→Cu→Cu2O; FeS→Fe3O4→CuFeO2.

Estimation of mineral liberation distribution functions to be used in modelling of impact and attrition milling

The paper aimed to reveal the liberation behaviours to define a methodology for calculating the liberation distribution functions of the minerals. This function can be incorporated into the existing comminution modelling so that the accuracy of the mineral-specific predictions is further improved. Within the scope, grinding tests were performed with complex copper ore, which was subjected to the ball and stirred milling. Following the grinding tests, size intervals were prepared for MLA where the mineral contents and liberation degrees of minerals of interest were determined. The data interpretation included the calculation of liberated galena, sphalerite, chalcopyrite and pyrite minerals’ amount to make a comparison between the technologies and the minerals. The study showed that the attrition milling produced more liberated minerals and galena had the highest degree of liberation irrespective of the technology chosen. Afterwards, a methodology similar to express the breakage events (t10) was developed to determine the liberation distribution function. This function implies the energy-dependent distribution of the liberated minerals to the subsequent sizes. This was named as L10 and determined for each of the grinding technology and mineral. Initial model fitting of the minerals via perfect mixing model showed that there was a good agreement between the measured and calculated size distributions however further improvements may be considered. As a result, the comminution modelling of both technologies was accomplished.

Study on the mechanical activation of malachite and the leaching of complex copper ore in the Luanshya mining area, Zambia

Mechanical activation (MA) of malachite was carried out by dry planetary grinding (DPG) and wet Isa grinding (WIG) methods. When the rotational speed was increased to 400 r/min in DPG, the specific surface area of malachite reached the maximum and the particle size reached the minimum of 0.7–100 µm. Agglomeration occurred between mineral particles when the rotational speed was increased to 580 r/min in DPG. However, no agglomeration was observed among particles with sizes 0.4–3 µm in WIG. X-ray diffraction analysis showed that, at a 580 r/min rotational speed in DPG, the amorphization degree of malachite was 53.12%, whereas that in WIG was 71.40%, indicating that MA led to amorphization and distortion of crystal structures. In addition, in the Fourier transform infrared (FT-IR) spectra of activated malachite, the bands associated with −OH, CO 3 2− and metal lattice vibrations of Cu-O and Cu-OH were weakened, and a new H-O-H bending mode and peaks of gaseous CO2 appeared, indicating that MA decreased the band energy, enhanced dihydroxylation, and increased the chemical reactivity of the malachite. Furthermore, the leaching behavior of copper ore was greatly improved by MA.

An investigation into the recovery of oxide copper from a complex copper ore using sulphidisation technique and hydroxamate and potassium amyl xanthate collectors

ABSTRACTThis study was aimed to increase the floatability of oxide copper from a complex copper sample. For this purpose, sulphidisation processes such as slug and controlled potential sulphidisation (CPS) and hydroxamate and potassium amyl xanthate (Z6) collectors were utilized and their results were compared with real conditions. The results indicated that about 9.46% of the recovery of oxide copper increased using 300g/t ammonium sulphide in the first step, and reached to 77.12%. Also, in this case, the recovery of sulphide copper was significantly improved. In addition, the findings demonstrated that applying 10 g/t of potassium octyl hydroxamate anionic collector, the recovery of oxide copper reached to 74.47% without any negative effect on the recovery of sulphide copper. Meanwhile, the simultaneous use of Z11 and Z6 as collector caused to increase about 3.63% of the recovery of oxide copper (71.29%). It was also found that the highest recovery of oxide copper could be obtained using CPS method and in this case, 10.34% of the oxide copper and 4.48% of the total copper improved and also the dosage of (NH4)2S decreased.

Development of HUMGEOSTAT: A New Geological Tool for Geostatistical Analysis of Mineral Deposit: A Case Study at Sin Quyen Mine (Northern Vietnam)

ABSTRACT This paper presents the results of the design and implementation of a new geological tool, named as HUMGEOSTAT, for advanced geostatistical analysis of mineral deposit, a case study at the Sin Quyen, one of the important mines for the Vietnam mining industry in Vietnam. The tool is developed based on the Stanford Geostatistical Modeling Software (SgeMS) platform, which is an open-source computer package for solving problems involving spatially related variables. The tool is capable of supporting users in reducing uncertainty and improving the quality of mining exploration tasks. The tool has all the functions needed to solve a complete geostatistical issues i.e. Variogram models (such as Spherical, Exponential, Gausian, Linear and Pure nugget effect); and four commonly used Kriging methods (Ordinary Kriging, Simple Kriging, Indicator Kriging, Co-Kriging). The tool was applied to test various types of input data and particularly for complex copper ore bodies of Sin Quyen mine. The results of analysis of orebody spatial structure has found that Cu content has non-uniform change, regional anisotropy in north-south (0±22.5°) direction, and anisotropic index is around 1.3. The mineral reserves are estimated according to sub-blocks and points in the orebody-space. The results indicate that the Ordinary Kriging (OK) has reliable results, variance estimation is small; the predicted result gained from OK have strong correlation (K=0.905) with ore samples. HUMGEOSTAT was applied at the Sin Quyen mine and various coal mines, the results were adapted with reality of mines.

Grain Size Distribution of Copper Ore as Means for Qualitative Evaluation of Its Lithological Composition

Information about the grain size distribution of a material plays an important role in optimizing production systems in various branches of industry. Analysis of particle size distribution in the run-of-mine material is frequently employed to verify the quality of drilling and blasting operations. Adequate software and improved grain size identification technologies not only help to monitor and evaluate the results of blasting operations, but also inform the selection of blasting methods which best correspond to particular geological and mining conditions both in surface mining and in underground mining. The accuracy of indirect, image-analysis methods used in the identification of grain size distribution motivated some pilot works aimed at using the grain size to evaluate the quality of a lithological complex copper ore deposit. Describing the run-of-mine material fed to the Ore Enrichment Plant (OEP) with the use of its grain size distribution may improve the techniques currently employed to optimize the energy efficiency of ore treatment processes. A model of ore flow in the underground transportation system, developed in the FlexSim environment, as part of the DISIRE research project, may prove a valuable optimization tool. This paper presents the results of preliminary research aimed at verifying whether grain size distribution of the run-of-mine material correlates with its lithological composition. The examinations covered grain size distribution in copper ore transported on belt conveyors in two mines in which the extracted ore has different lithology. The research was performed with the use of photogrammetric techniques and the Split Desktop 4.0 computer application. The advantage of the proposed technique is that it can be used at any location in the mine. The analysis was performed on the photographic material collected in situ at the “Lubin” mine. This material was supplemented with qualitative data stored in the Run-Of-Mine Ore Monitoring system (further: MOPRONA), as defined on the basis of channel samples collected on the day of tests.

Evaluation of complex copper ore sorting: Effect of optical filtering on particle recognition

In mixed and multi-component mineral systems, the reflectance spectra of individual minerals interfere with the reflectance/absorbance features of other minerals and random spectra can form. This contradictory case causes difficulty in implementing ore sorting to certain minerals. Hence, filtering out certain wave lengths may prevent this situation which makes it difficult for an ore sorter to perform a selective and efficient separation. The scope of this study is to investigate the feasibility of the optical filtering to enhance the differences in the reflectance features of mineral grains, and to compare the possible separation performances of the ore sorters under the best filtered and unfiltered conditions.Within the experimental studies, a new experimental setup which runs its uniquely coded software was designed. Additionally, an adjustable filter cartridge apparatus was developed enabling to mount the wavelength specific filters in front of the conventional sensors which support universal f-mount type lenses. A representative sample batch consisting of 31 grains of complex copper ore was prepared. Filtered and unfiltered images of each grain in between 450 and 1650 nm wavelength range were acquired carefully with the designed experimental setup. Following the data extraction by imaging studies, each particle was weighed, ground, and analyzed to determine chemical compositions. Thus, the reflectance values and chemical analysis data of each particle with each filter were obtained. Principal component analysis (PCA), partial least square analysis (PLS) and stepwise multiple linear regression (SMLR) methods were used to evaluate the resulting data in order to establish meaningful relationships between dominant chemical contents and reflectance values of each individual particle. Hence, the effect of using optical filters in altering the differences among the reflectance values of complex copper ore grains has been determined. Following the determination of best filters and wave lengths, projected product qualities of a conjectural optical sorting operation integrated with optical filters have been analytically investigated. It was concluded that an alteration in the relationship between % sulphide content and reflectance values was observed over 1500 nm wavelengths in comparison to the unfiltered and other filtered conditions. Evaluation of the overall results showed that up to 73.30% of Au, 96.14% of Ag, and 86.24% of CuFeS2 in feed can be recovered when a long-pass 1500 nm filter was used.

Influence of NH 4 HF 2 activation on leaching of low-grade complex copper ore in NH 3 -NH 4 Cl solution

In this study, the influence of NH4HF2 activation on the leaching of low-grade complex copper ore in NH3-NH4Cl solution was studied. The related thermodynamic, optimization, and kinetic studies were investigated by an exponential computation method, orthogonal tests, and shrinking core model, respectively. The results indicate that NH4HF2 can react with Fe2O3, SiO2 and Al2O3, and the concentration of NH4HF2 is the crucial factor on the digestion of the gangues combined with copper oxides. The optimum leaching conditions were established as 3 mol/L NH4Cl, 2.5 mol/L NH3·H2O, 1 mol/L NH4HF2, 10 mL/g liquid to solid ratio, 60 °C, and 3 h. Under the conditions, the leaching efficiency of copper was 89.39%. The leaching process is controlled by the diffusion of reactants across product layer, and the activation energies corresponding to 0, 0.1, 0.3, and 0.5 mol/L NH4HF2 were calculated as 27.9, 19.8, 30.7, and 32.6 kJ/mol, respectively.

The recovery of oxide copper minerals from a complex copper ore by sulphidisation

Kansanshi copper mine is situated in the north western province of Zambia. As a result of the mineral variations, the processing plant treats three distinct ore types, viz. oxide, sulphide and mixed. The objective of this study was to investigate the floatability of a complex Kansanshi mixed copper ore with a special focus on the sulphidisation process. Controlled potential sulphidisation (CPS) is preferred over slug sulphidisation as the industry standard for the flotation of oxide copper minerals. Two potential ranges were investigated in this study; −300 to −400mV and −400 to −500mV. Optimum flotation performance was observed in the potential range of −300 to −400mV and a NaHS:SIBX ratio of 7:1 during CPS. An economic analysis of the results showed that CPS did not change the recoveries compared to slug addition but required much lower dosages of NaHS.

A New Heterotrophic Strain for Bioleaching of Low Grade Complex Copper Ore

A new heterotrophic strain, named Providencia sp. JAT-1, was isolated and used in bioleaching of low-grade complex copper ore. The strain uses sodium citrate as a carbon source and urea as a nitrogen source to produce ammonia. The optimal growth condition of the strain is 30 °C, initial pH 8, sodium citrate 10 g/L and urea 20 g/L, under which the cell density and ammonia concentration in the medium reached a maximum of 4.83 × 108 cells/mL and 14 g/L, respectively. Ammonia produced by the strain is used as the main lixiviant in bioleaching. Bioleaching results revealed that higher strain growth led to a higher copper recovery, while higher pulp density will cause a greater inhibitory effect on strain growth and ammonia production. The copper extraction reached the highest value of 54.5% at the pulp density of 1%. Malachite, chrysocolla and chalcocite are easy to leach out in this bioleaching system while chalcopyrite is difficult. Results of comparative leaching experiments show that bioleaching using JAT-1 is superior to ammonia leaching at the same condition. The metabolites produced by the strain other than ammonia are also involved in bioleaching.

Mineralogy, Geochemistry and Stable Isotope Studies of the Dopolan Bauxite Deposit, Zagros Mountain, Iran

A new heterotrophic strain, named Providencia sp. JAT-1, was isolated and used in bioleaching of low-grade complex copper ore. The strain uses sodium citrate as a carbon source and urea as a nitrogen source to produce ammonia. The optimal growth condition of the strain is 30 C, initial pH 8, sodium citrate 10 g/L and urea 20 g/L, under which the cell density and ammonia concentration in the medium reached a maximum of 4.83 × 108 cells/mL and 14 g/L, respectively. Ammonia produced by the strain is used as the main lixiviant in bioleaching. Bioleaching results revealed that higher strain growth led to a higher copper recovery, while higher pulp density will cause a greater inhibitory effect on strain growth and ammonia production. The copper extraction reached the highest value of 54.5% at the pulp density of 1%. Malachite, chrysocolla and chalcocite are easy to leach out in this bioleaching system while chalcopyrite is difficult. Results of comparative leaching experiments show that bioleaching using JAT-1 is superior to ammonia leaching at the same condition. The metabolites produced by the strain other than ammonia are also involved in bioleaching.

Investigation on Copper Flotation from a Complex Copper Ore, Yunnan Province

The mineral processing flow sheet and reagent system of flotation copper minerals from alarge copper sulfide deposit in Yunnan were fully investigated. The results indicated that the optimum conditions for flotation of copper minerals from the material were identified as follows: grinding fineness of 80%(-0.074mm), dosage of CaO 800g/t, butyl xanthate 100g/t.Under such condition, a copper recovery of 90.57% with a concentrate grade of 19.52% was achieved from the material using a closed circuit flow sheet of one-stage roughing flotation, two-stage cleaning flotation and two-stage scavenging flotation.

Characterization and kinetic study on ammonia leaching of complex copper ore

Ammonia leaching kinetics of a complex Cu-ore assaying 8.8% Cu and 36.1% Fe was examined. Mineralogical characterization indicated that the major phase of the ore was siderite with chalcopyrite as the major sulfide mineral. The effects of parameters such as agitation, temperature, NH3 concentration, particle size and oxygen partial pressure (pO2) were investigated. Under the standard leaching conditions of 125–212 µm particle size, 120 °C, 1.29 mol/L NH3 and 202 kPa of pO2, about 83% Cu could be selectively extracted in 2.5 h. However, when using higher NH3 concentration and lower particle size, more than 95% extraction was achieved. The leaching process was found to be surface reaction controlling. The estimated activation energy was (37.6±1.9) kJ/mol and empirical orders of reaction with respect to pO2 and [NH3] were about 0.2 and 1, respectively.

Efficiently Utilizing a Low Grade and Complex Copper Ore by Flotation

Based on the analysis of the properties of the copper ore from Jinggu area in Yunnan province, a suitable technical route was presented for processing of eligible copper concentrate and the main factors i.e. grinding fineness, Na2S dosage and collector dosage, affecting the quality of roughing concentration was investigated. On this basis, a close-circuit flotation test scheme was preceded, which obtained a high quality copper concentrate with Cu grade of 16.08%, copper recovery of 58.52%. The recovery of copper concentrate is much lower than the Cu recovery of roughing concentrate from the condition experiments. This may be contributed to the fact that fine slime carried by middling worsens the separation of copper minerals and gangues. The Mo was enriched in concentrate, which is significantly considered to recovery in further work.

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.

Development of a selective flocculation process for a complex copper ore

Problems encountered in developing a selective flocculation process for a complex copper ore and ways of overcoming these difficulties are reported. To obtain a useful enrichment ratio, multiple stages of flocculation and redispersion were found necessary in order to release entrapped, unwanted particles. Particular attention was given to the dispersion process of the ore suspensions, and the importance of mechanical and chemical factors were established. The effects of solids content and quality of water on the performance of selective flocculation have been investigated. The possibility of developing new, selective or more powerful dispersants was confirmed and one such reagent was tested.