Copper Sulfide Minerals Research Articles

Investigation of effective operating parameters on carrying capacity in column flotation of copper sulfide minerals

ABSTRACTThe carrying capacity (Ca) in column flotation can be determined by experiments in terms of mass of solids per unit time per unit column cross-sectional area. The estimation of Ca has been typically defined by a simplified statement on the basis of representative particle size and the floatable mineral density. Although this statement encountered with several assumptions and limited ranges of the data that increase errors for other applications, in Ca expressions, the effect of particular variables, such as particle size, feed solids rate, bubble diameter, air flow rate, feed solid content, frother dosage, and froth height should be considered. In this study, the effects of these parameters on the Ca were investigated in column flotation using copper sulfide ore. It was found that when the feed solid rate increased, the concentrate solid rate increased to a certain point, whereafter it started to decrease. When the air flow rate increased, the Ca first increased then drastically decreased. In low feed flow rates, the increase in frother rate led to the higher carrying capacity, whereas in feed flow rates over 1.2 cm/s, the carrying capacity in frother rate of 45 ppm was more than 75 ppm. By decreasing the froth height and increasing the solid percentage (up to 30%), Ca increased. The results of the experiments at various feed particles sizes showed that the particles with size 45–63 µm had the maximum carrying capacity.

Tectonic and metallogenic evolution of the Curaçá Valley Copper Province, Bahia, Brazil: A review based on new SHRIMP zircon U-Pb dating and sulfur isotope geochemistry

More than three hundred mafic-ultramafic bodies of different sizes, containing copper sulfide mineralization, are present in the Curaçá River Valley Copper Province, northeastern São Francisco Craton, Bahia State, Brazil, covering an area of about 1700 km2. The basement, supracrustal sequence, and mafic-ultramafic intrusive rocks underwent granulite facies metamorphism and were reworked during the evolution of the Itabuna-Salvador-Curaçá Orogeny, resulting in retrograde metamorphism to the amphibolite facies, partial migmatization, and intrusion of granitic and syenitic rocks. During the slow and progressive rise of the terrain, hydrothermal reactions mainly along shear zones retrogressed part of these rocks to assemblages characteristic of the greenschist metamorphic facies. The main orebodies with copper sulfide minerals are associated with pyroxenite, mica-rich (glimmerite) and noritoid rocks. The present investigation focuses on the major Caraíba, Sussuarana, Surubim, and Vermelhos deposits. Chalcopyrite and bornite compose the ore, in a ratio of 70–30%, with copper grade varying between 0.69% and 1.4%, and associated gold and silver. The sulfide minerals are invariably accompanied by magnetite. Two mineralization styles are distinguished: (i) disseminated in non-altered mafic-ultramafic rocks; and (ii) tectonic controlled related to hydrothermal alteration zones. New geochronological data show that quartz-microcline metasomatites of the Caraíba Mine contain Neoarchean inherited zircons (upper intercept at 2723 ± 51 Ma), related to the early stages of magmatism, whereas Orosirian ages (2047 ± 12 and 2042 ± 15 Ma) are related to the main hydrothermal mineralization activity. Norite from the Surubim Mine has a Paleoproterozoic age (2047 ± 11 Ma), and the dated gabbro shows Pb loss in the Neoproterozoic, probably related to the Brasiliano Orogeny (670–490 Ma). Previous studies have demonstrated that the main hydrothermal event is Paleoproterozoic. Phlogopite Ar-Ar dating from the Caraíba Mine yields plateau-ages around 2000–2100 Ma. A cluster of δ34S values approaching zero is related to interstitial sulfide minerals in the least-altered ultramafic rocks, while values above and below zero are related to remobilized sulfides. These data support the hypothesis of the existence of a primary (magmatic) mineralizing event, alleged to have precipitated disseminated, interstitial sulfide minerals, and a second (hydrothermal) event, responsible for the economically more important mineralization, which is structurally controlled and related to significant potassic alteration. The sulfide minerals are associated with different generations of magmatic and hydrothermal magnetite, as well as distal plagioclase and microcline alteration halos. The combination of these features reaffirms the concept that the Curaçá Valley deposits may be part of the same alteration system, as described in IOCG deposits, with the deepest deposits being located further south. Based on the data obtained during the present study, it is possible to establish a tectono-metallogenic evolutionary model to explain the genesis of the copper mineralization in the Curaçá Valley. The mafic-ultramafic bodies were emplaced as multiple intrusions in Neoarchean arc-related gneisses and chemical sediments, along with bornite and chalcopyrite mineralization. The sulfide minerals that preserve the characteristics of this stage are chalcopyrite or bornite, both with δ34S values around 0‰V-CDT.A continental collision affected the Caraíba arc and the related sequences between 2100 and 2080 Ma. During this Rhyacian-Orosirian orogeny, deformation and amphibolite-granulite facies metamorphism, the rocks underwent partial melting, and sapphirine formation developed. Between 2050 and 2020 Ma, the main mineralization stage took place at Caraíba, Vermelhos, and Surubim, which corresponds to an earlier stage in the Sussuarana deposits. The southern deposits were formed deeper than those to the north, resulting in less extensive potassic alteration and related hydrothermal mineralization. The sulfide minerals of the deeper deposits have negative δ34S (between 0‰ and −6.81‰), to slightly positive values, where the igneous protoliths are best preserved. This alteration took place near the brittle-ductile boundary, mainly associated with ductile structures.The latest stage of mineralization took place between 1950 and 1920 Ma, in the Caraíba, Vermelhos and Surubim deposits, along with major sulfide remobilization in Sussuarana. This stage was characterized by the participation of oxidizing fluids, possibly meteoric waters, which raised the δ34S values up to +11.77‰.

Platinoids in the Kaalamo Differentiated Massif in the Northern Ladoga Region, Karelia, Russia

The Kaalamo massif is located in the Northern Ladoga region, Karelia, on the extension of the Kotalahti Belt of Ni-bearing ultramafic intrusions in Finland. The massif, 1.89 Ga in age, is differentiated from pyroxenite to diorite. Nickel–copper sulfide mineralization with platinoids is related to the pyroxenite phase. The ore consists of two mineral types: (i) pentlandite–chalcopyrite–pyrrhotite and (ii) chalcopyrite, both enriched in PGE. Pd and Pt bismuthotellurides, as well as Pd and Pt tellurobismuthides, are represented by the following mineral species: kotulskite, sobolevskite, merenskyite, michenerite, moncheite, keithconnite, telluropalladinite; Pt and Pd sulfides comprise vysotskite, cooperite, braggite, palladium pentlandite, and some other rare phases. High-palladium minerals are contained in pentlandite–chalcopyrite–pyrrhotite ore. Native gold intergrown with kotulskite commonly contains microinclusions (1–3 μm) of Pd stannides: paolovite and atokite. Ore with 20–60% copper sulfides (0.2–6.0% Cu) contains 5.1–6.6 gpt PGE and up to 0.13–2.3 gpt Au. Pd minerals, arsenides and sulfoarsenides of Pt, Rh, Ir, Os, and Ru are identified as well. These are sperrylite, ruthenium platarsite, hollingworthite, and irarsite; silvery gold and paolovite have also been noted. All these minerals have been revealed in the massif for the first time. The paper also presents data on the compositions of 25 PGE minerals (PGM) from Kaalamo ores.

Industrial Tests to Modify Molten Copper Slag for Improvement of Copper Recovery

In this article, to improve the recovery of copper from copper slag by flotation process, industrial tests of the modification process involving addition of a composite additive into molten copper slag were conducted, and the modified slag was subjected to the flotation process to confirm the modification effect. The phase evolution of the slag in the modification process was revealed by thermodynamic calculations, x-ray diffraction, optical microscopy and scanning electron microscopy. The results show that more copper was transformed and enriched in copper sulfide phases. The magnetite content in the modified slag decreased, and that of “FeO” increased correspondingly, leading to a better fluidity of the molten slag, which improved the aggregation and growth of fine particles of the copper sulfide minerals. Closed-circuit flotation tests of the original and modified slags were conducted, and the results show that the copper recovery increased obviously from 69.15% to 73.38%, and the copper grade of concentrates was elevated slightly from 20.24% to 21.69%, further confirming that the industrial tests of the modification process were successful. Hence, the modification process has a bright future in industrial applications for enhancing the recovery of copper from the copper slag.

Improvement of Sulfatizing Roasting of Refractory Copper-Zinc Sulphide Raw Material

Sulfatization roasting of refractory copper-zinc sulphide raw material is studied. Test material chemical and phase compositions are examined. Thermodynamic calculations of possible sulfatization reactions are performed. Phase transformations, mechanisms of decomposition, and oxidation of sulphide minerals are studied using thermogravimetric and differential-thermal analyses. Equilibrium distribution of the system components during copper-zinc sulphide raw material roasting is modelled using an HSC Chemistry 6.0 computer program. Optimum conditions are established for roasting in which copper and zinc sulphide minerals are converted into sulphate form and iron is converted into oxide. Consolidated tests of sulfatizing roasting of copper-zinc sulphide middlings confirm results of experimental studies.

Towards industrial implementation of glycine-based leach and adsorption technologies for gold-copper ores

ABSTRACTThe technology to selectively leach gold, silver and base metals from ores, concentrates, and wastes, using an alkaline glycine solution, has initiated significant interest in using the new technology in various environments such as in situ, in-place, dump, heap, and vat and agitated tank leaching. It has been shown that glycine acts synergistically with a number of other lixiviants to lower the net consumption of the other lixiviants while allowing low-cost glycine solution recovery. Glycine is a non-toxic, stable, environmentally benign reagent that is available in bulk industrial quantities. It has the ability to dissolve most copper oxide and sulphide minerals, as well as native copper, whilst not interacting with acid-consuming gangue nor dissolving iron and various or ubiquitous gangue elements. It acts synergistically with small amounts of cyanide to leach gold-copper ores at leach rates higher than either glycine or cyanide on their own, while significantly reducing cyanide consumption and eliminating detoxification requirements. The leaching behaviour of various glycine-based systems will be reviewed, followed by the evaluation of the adsorption of gold onto activated carbon. Where the economics merit it, copper can be easily recovered using solvent extraction or sulphide precipitation.

The effect of silver on the acidic ferric sulfate leaching of primary copper sulfides under recycle solution conditions observed in heap leaching. Part 1: Kinetics and reaction mechanisms

The current focus for the treatment of low-grade copper resources is through heap leaching with the aid of bacteria. However, it is well known that chalcopyrite and other copper sulfide minerals such as enargite are refractory and suffer from slow leaching kinetics and poor overall extraction due to becoming passivated. Researchers have observed that certain additives such as silver can considerably improve the extraction. What is less understood is if additives like silver can effectively promote the extraction under recycle heap leach conditions, and if so, the mechanism of its action. The study reported in this paper addresses these questions. The standard leaching conditions used were based on a simulated long term recycle solution composition. It was observed that silver addition greatly promoted the extraction of copper from the ore samples under those conditions. Experiments at varied silver concentrations showed that there is a minimum concentration of silver needed to achieve a significant enhancement in the rate and extent of the extraction of copper. For example, for the leaching of the chalcopyrite ore tested in the present study a silver addition of 0.02g/L resulted in 25% copper extraction in 10days, whereas 0.05g/L Ag resulted in over 90% extraction in the same period. It has also been shown that the silver needs to be present at the start of the leaching or precipitated onto the surface of the minerals before adding the lixiviant, to achieve the catalytic effect. Iron extraction appeared to be retarded in the presence of silver, which suggests that silver not only catalyses chalcopyrite and enargite leaching but it may also be galvanically protecting pyrite from dissolution, although the lower iron observed is at least partly attributable to the formation of argentojarosite.

Mineralogical Dynamics of Primary Copper Sulfides Mediated by Acidophilic Biofilm Formation

Bioleaching of copper sulfides is catalyzed by iron-and sulfur-oxidizing acidophilic microorganisms attached to the mineral surface forming a biofilm. However, the link between copper sulfides bioleaching and biofilm formation is not yet fully understood. Understanding the factors that are limiting the bioleaching kinetics for different copper sulfide minerals through exhaustive mineralogical analysis of the mineral surface with concomitant biofilm formation during the leaching process will deliver new process conditions with enhanced kinetics and higher copper recovery. In this work we have developed and standardized a reproducible flow cell method able to mimic heap/dump bioleaching laminar flow conditions to study the mineralogical dynamics by advanced mineralogical analysis including QEMSCAN and SEM-EDS coupled to biofilm formation analysis. Based on this method, the bioleaching mineralogical dynamics of primary copper sulfides (enargite (Cu3AsS4), chalcopyrite (CuFeS2) and bornite (Cu5FeS4)) have been determined in the presence of biofilm formation. Supported by the observed mineralogical dynamics, different mechanisms of dissolution for bioleaching were observed as well as selective biofilm formation over the mineral surface, showing enhanced conditions for copper recovery.

Bioelectrochemical Leaching of Copper Sulfide Minerals

The objective of this study is to improve the understanding of copper sulfides dissolution and to use this knowledge for optimization of process parameters for commercial application of electrochemical bioleaching of chalcopyrite concentrates in stirred bioreactors. From the results of this study, the importance of the oxidation reduction potential (ORP) on the catalytic interaction between chalcopyrite and pyrite can be pointed out as the main parameters for successful bioprocessing of chalcopyrite concentrates. Under these conditions, the optimization of the average particle size of feed (D80) and adjusting the ORP in the range between 400-450 mV are important criteria for increasing the electrochemical bioleaching rate of chalcopyrite concentrates. It seems that the main reason for the increased copper recovery could be the control and prevention of chalcopyrite passivation resulting from improved galvanic interaction between copper sulfide minerals, here especially chalcopyrite and pyrite in the selected ORP range and the right particle size distribution of feed. At optimum conditions, the copper extraction from chalcopyrite flotation concentrate during 7 days of continuous electrochemical bioleaching operations in stirred tanks was about 95%, which should be high enough to justify the process economically.

Development of partial extraction methods to estimate abundance of copper-iron sulphide minerals in the Escondida Norte porphyry copper deposit, Chile

Studies were conducted by Minera Escondida, Ltda. (MEL) between 1995 and 2003 to support an investment decision to open Escondida Norte, an enriched porphyry copper deposit adjacent to the Escondida mine and processing facilities. Due to the importance of copper-iron sulphide minerals in predicting metallurgical performance in both process alternatives, a quantitative spatial model of copper-iron sulphide mineral abundances was determined to be a critical study component. A suite of total and partial copper analyses already in common use was chosen to maximize relative selectivity among the major copper sulphide minerals in the mineral deposit. These analyses were merged with partial and total sulphur analysis and combined with a novel approach to interpret the analytical results as normative mineral estimates of chalcocite, covellite, chalcopyrite and pyrite content. Development and validation of the normative mineral estimates included verification on the analytical stability and reproducibility of the chemical analyses, determination of extraction rates on synthetic mineral standards, and comparison with modal mineral abundance on natural ore samples. Uncertainty of individual normative copper sulphide minerals is estimated at ±5% (95% confidence interval), while uncertainty on pyrite content is ±12%. The uncertainty of the normative mineral estimates are comparable to uncertainty of corresponding modal mineral estimates, and differences between modal and normative estimates are largely within the estimation uncertainty. While the methods were originally developed for a simple association based on supergene chalcocite ± covellite replacing and overprinting hypogene chalcopyrite + pyrite, subsequent work developed normative mineral models for bornite + chalcopyrite hypogene and mixed copper oxide-sulphide supergene mineralization.

Selective flotation of enargite from copper sulphides in Tampakan deposit

Recent research has demonstrated promising results showing the possibility of separating arsenic-copper sulphides from other copper minerals by controlling the potential of the flotation pulp. Most of these studies were conducted on single mineral systems, and the selective removal of arsenic-copper minerals in real ore systems is not well understood, particularly, the effects of mineralogical properties such as liberation and mineralogical association.In this study, two distinct ore samples, termed low arsenic sample (LAS) and high arsenic sample (HAS) were selected from the Tampakan copper-gold deposit in the Philippines, providing a range of arsenic levels. The selective separation of enargite from other copper sulphide minerals in a rougher flotation system under controlled pulp potential was investigated for both samples.

High-performance reagent modes for flotation recovery of platiniferous copper and nickel sulfides from hard-to-beneficiate ores

The paper presents the results of the recent research performed in IPKON Russian Academy of Sciences that deals with development and substantiation of new selective reagents for effective flotation recovery of non-ferrous and noble metals from refractory ores. The choice and development of new selective reagents PTTC, OPDTC, modified butylxanthate (BXm) and modified diethyl-dithiocarbamate (DEDTCm) to float platiniferous copper and nickel sulfide minerals from hard-to-beneficiate ores is substantiated. The mechanism of reagents adsorption and regulation of minerals floatability is discussed. The study of reagent modes indicates that by combining PTTC with the modified xanthate results in 6 – 7 % increase in the recovery of copper, nickel and PGM in the flotation of the low-sulfide platiniferous Cu-Ni ore from the Fedorovo-Panskoye deposit. The substitution of OPDTC for BX makes it possible to increase recovery of Pt by 13 %, Pd by 9 % and 2 – 4 times the noble metal content in the flotation concentrate.

Relating the Mineralogical Characteristics of Tampakan Ore to Enargite Separation

The mineralogical characteristics of enargite-bearing copper ores from the Tampakan deposit have been investigated as the means to understanding the separation of enargite from other copper sulphides (chalcopyrite and bornite). It was found that a separation of these minerals was possible after grinding the ore samples to a P80 of 90 microns; enargite tends to be ground more readily than the other copper sulphide minerals present in ore samples tested, and consequently, it mostly reported to the fine size fractions.

Kinetic Analysis of Copper Sulfide (Chalcopyrite) Dissolution by Moderately Thermophilic Bacteria

ABSTRACTThe objective of this study was to improve the basic understanding of copper sulfide minerals dissolution during bioleaching of flotation concentrate and to analyze the dissolution kinetic. The results show that the sulfide mineral dissolution kinetic changes with operation time. Both surface reaction and diffusion through product layer were found to be effective parameters for the rate of reaction with various degrees of influence. In other words, the whole dissolution process can be divided into two intervals. At the beginning, the effect of surface reaction on the reaction rate is obvious. With increasing operation time and formation of layer on the surface of copper sulfides, the influence of diffusion through the layers increases. However, the dissolution rate depends also on the particle size distribution index (d80) and pulp density. With decreasing particle size and pulp density, the influence of surface reaction on the dissolution rate is increasing more than that of diffusion through layers.

Geochemistry, petrology, and mineralization in volcanic rocks located in south Neyshabour, NE Iran

This paper presents the new geochemical isotopes Sr and Nd, and the mineralization data for the south Neyshabour volcanic rocks located in NE Iran. Based on the chemical classifications, the studied rocks are basaltic trachy andesite, trachy andesite, trachyte, and trachy dacite in composition. All the analyzed volcanic rocks display enrichment in light rare earth elements (LREE) relative to the heavy rare earth elements (HREE), have significant negative Ti and Nb anomalies, and have a positive U anomaly. The tectonic discrimination diagrams for the volcanic rocks in the studied area show a post-collisional arc environment. These characteristics are the specifications of the subduction-related volcanic rocks generated in a post-collisional setting. The initial 87Sr/86Sr ratios ranging from 0.70408 to 0.70593and the eNdi values between +3.34 and +5 for the four samples analyzed indicate that the studied rocks are derived from a lithospheric mantle source. Finally, it is concluded that these volcanic rocks should have formed in a post-collisional environment that followed the Neo-Tethys subduction. There are strong evidence for copper mineralization in these volcanic rocks. The main copper oxide minerals are malachite and atacamite. The copper sulfide minerals such as chalcocite, minor bornite, and covellit are also present. Chalcocite is the most abundant sulfide ore mineral present in this area. This mineralization is observed as open space filling and thin veinlets, and it is partially controlled by linear structures and fault zones. Based on the identified characteristics, this ore deposit is hydrothermal. Carbonate alteration is frequently seen in the area but argillic alteration is very low, and this issue displays a hydrothermal solution with an alkaline pH.

Ore geology of the copper sulfide mineralization in the Rudabánya ore-bearing complex

The mineralized complex of Rudabanya hosts deposits of several mineral resources including base metal ores. Recent exploration provided new information on the enrichment of copper within this complex. The primary copper mineralization consists of sulfides. The paragenetic sequence starts with fahlore, continues with bornite, and concludes in chalcopyrite formation partly replacing the former phases. It is hosted by brecciated carbonate rocks, overprinting the paragenesis of the iron metasomatism. It was found to be spatially separated from zinc and lead enrichments. Oxidation and a subsequent new pulse of mineralization formed several new copper, zinc, and lead minerals, probably by the remobilization of the primary parageneses.

Late Bronze Age copper smelting in the southeastern Alps: how standardized was the smelting process? Evidence from Transacqua and Segonzano, Trentino, Italy

The smelting copper slags from the archaeological sites of Transacqua and Segonzano in Trentino (Italy) were fully analysed to study the extraction of copper from copper and iron sulphide minerals that were carried out in the southeastern Alps during the Late Bronze Age. A combined approach involving physical, chemical, mineralogical and petrographic analyses was applied on over 130 copper slags from Transacqua and Segonzano. Three different types of slags were distinguished from the mineralogical and chemical points of view, differing in the size and relative amount of the unreacted sulphides and matte, the size of metallic copper prills, the ratio between unreacted quartz and newly formed silicate phases and viscosity. By combining all the observations, it is suggested that the three types of slags are the product of a Cu-smelting process formed by three main operations: slagging, matting and refining, which were standardised in the southeast Alps between the fourteenth and the eleventh century BC.

Corrosion of copper and authigenic sulfide mineral growth in hydrothermal bentonite experiments

The focus of this experimental work is to characterize interaction of bentonite with possible used-fuel waste container materials. Experiments were performed up to 300 °C at 150–160 bars for five to six weeks. Bentonite was saturated with a 1900 ppm K-Ca-Na-Cl-bearing water with Cu-foils. Copper rapidly degrades into chalcocite (CuS2) and minor covellite (CuS) in the presence of H2S. Chalcocite growth and corrosion pit depths were measured for four different experimental runs yielding corrosion rates between 8.8 and 116 μm/yr depending on duration of experiment, brine composition, and clay type (bentonite vs. Opalinus Clay). Results of this research show that although pit-corrosion is demonstrated on Cu substrates, experiments show that the reactions that ensue, and the formation of minerals that develop, are extraordinarily slow. This supports the use of Cu in nuclide-containment systems as a possible engineered barrier system material.

Geology and geochemistry of the Suaqui Verde deposit: A contribution to the knowledge of the Laramide porphyry copper mineralization in south central Sonora, Mexico

The Suaqui Verde porphyry copper deposit is a small ore body of about 20milliontons of oxide ore grading 0.29% copper, located ~8km E-NE of the town of Suaqui Grande in east-central Sonora, northwestern Mexico. The largest and better-known deposits occur in northern Sonora, whereas those from central and southern Sonora are smaller and poorly studied. This paper contributes with new geological and geochemical data to characterize the Suaqui Verde porphyry copper prospect, which may help to understand the porphyry copper mineralization in central Sonora. The Cu mineralization is centered on a 57±0.3Ma old quartz-feldspar porphyry stock, intruding co-magmatic Laramide volcanic and plutonic rocks. The Suaqui Verde porphyry copper system is characterized by widespread phyllic alteration dominated by quartz-sericite, propylitic and local potassic alteration, with Cu, Mo, and Fe sulfide mineralization emplaced in quartz veinlets filling stockwork zones. Quartz-tourmaline breccias, presumably pre-dating the copper sulfide mineralization, occur in the southern part of the deposit, apparently forming the apical parts of the equigranular plutons. Geochemical data of plutonic and volcanic rocks indicate derivation from subduction related calc-alkaline and metaluminous to slightly peraluminous magmas. Light REE enriched normalized patterns, with negative Eu anomalies resemble typical composition of Laramide magmatic rocks in northwestern Mexico. However, positive Eu anomalies in three of the samples indicate that some magmatic stages underwent a process that increased the Eu+2/Eu+3 ratios in the liquid, possibly associated with changes in the oxidation-reduction conditions. Chondrite-normalized multi-elemental diagrams show negative Nb-Ta, P and Ti anomalies, coupled with positive Rb, Th, U, Sr and Pb anomalies, strongly suggesting a subduction-related magmatic arc affinity. The mineralized system was segmented and tilted during the Cenozoic Basin and Range extension, which exhumed the hypogene sulfide zone, promoting supergene enrichment processes and subsequent transport of copper solutions that developed weak exotic copper mineralization.

Paragenesis and fluid evolution of the Halasu III porphyry Cu deposit, East Junggar (NW China): Implications for the Paleozoic multiphase superimposing mineralization in the Central Asian Orogenic Belt

The Halasu III deposit, an important Cu deposit in the southernmost part of the Halasu porphyry Cu belt, is situated in the East Junggar block in NW China. Copper and Mo sulfide mineralization commonly occurs as disseminations or veinlets, and is mainly associated with Devonian granodiorite porphyry. Our detailed field geological investigation identified late-stage high grade Cu sulfide-bearing veining superimposed on the earlier porphyry Cu–Mo mineralization.Four hydrothermal alteration and mineralization stages were identified, namely the early epidote alteration (Stage I), porphyry-style alterations (Stage II comprising II-A potassic, II-B propylitic and II-C phyllic alteration sub-stages), late veining (Stage III) and supergene processes (Stage IV) in the northern- and southern mineralization zones at Halasu III. Multiphase granodiorite- and alkali granite dykes intruded the Beitashan Formation volcanic rocks, generating the early epidote alteration. Potassic alteration (Stage II-A) occurred in and around the NNW-treading granodiorite dykes, while the propylitic alteration (Stage II-B) occurred in the intrusions or volcanic wall rocks around the potassic zone. These early alteration assemblages were overprinted by the subsequent, structurally-controlled phyllic alteration (Stage II-C) confined within the granodiorite porphyry. Late veins (Stage III) include sulfide-bearing (Stage III-A) and sulfide-barren (Stage III-B) ones. Supergene process (Stage IV), represented by hematite and jarosite replacing primary sulfides, extends tens of meters down depth and is commonly fracture-controlled.Three fluid inclusion (FI) types were recognized, namely Type A (single-phase), B (liquid–vapor two-phase) and C (liquid–vapor–solid three-phase). For Type B FIs, those of potassic alteration homogenized at 183–347°C, with corresponding salinities of 6.2–17.8wt.% NaCl equiv. The propylitic and phyllic FIs homogenized at 172–425°C and 231–352°C, respectively, with the corresponding salinities of 0.9–14.0wt.% NaCl equiv. and 0.4–10.5wt.% NaCl equiv. The sulfide-bearing vein FIs homogenized at 243–410°C (Stage III-A-1), 260–362°C (Stage III-A-2) and 117–235°C (Stage III-A-3), along with the corresponding salinities of 1.9–9.2wt.% NaCl equiv., 1.1–6.7wt.% NaCl equiv. and 6.5–17.1wt.% NaCl equiv., respectively. The sulfide-barren vein FIs yielded homogenization temperatures of 260–380°C (Stage III-B-1) and 114–297°C (Stage III-B-2), with corresponding salinities of 1.7–9.8wt.% NaCl equiv. and 0.2–13.6wt.% NaCl equiv., respectively. We suggest that hydrothermal veins at Halasu III may have undergone complex and superimposing alteration due to the episodic reopening of the preexisting veins, with Stage III-A-3 veining overprinting the phyllic alteration and Stage III-A-2 veining. Stage III-B-2 veining superimposed on the potassic alteration, as well as on Stages III-A-1 and III-B-1 veining.Paragenetic sequence and fluid evolution at Halasu III indicate that these complex hydrothermal alteration stages were formed in accordance with the regional tectonic evolution. These various alteration and mineralization stages at Halasu III deposit reveal a prolonged history of magmatic and hydrothermal processes extending episodically from the Middle Devonian to Middle Permian, wherein early mineralization was overprinted by late hydrothermal events. Such superimposed mineralization may occur commonly in the Paleozoic Central Asia Orogenic Belt.