Academic literature on the topic 'Gold-copper-bismuth ore deposits'

We have used the “Leader” and “PROFILE” software programs to analyze spectral study results for 242 native gold samples from lode deposits and placer relics of the Yugler mineral district. The Yugler black shales host gold mineralization characterized by the geochemical specialization in lead and copper, which assigns it to the style of gold mineralization at the Degdekan deposit but distinguishes it from the majority of similar deposits in Russia and abroad. Native gold in ore bodies and placers displays a distinct geochemical specialization. Native gold from ore bodies is high in As, Bi and Pb, from the Yugler placer in Cu, Pb, Fe and Mn, and Spokoiny and Matrosov’s placers in Sb and Ag. Vertical zoning of mineralization manifests itself as low-grade antimonious grains of native gold in eroded parts of the sequence and high-grade bismuth-lead-arsenious grains in its preserved parts. The mineral-geochemical formation model of the Yugler lode-placer district is a space-time succession of copper-polymetallic mineral assemblages replaced by arsenic-bismuth-polymetallic and then by silver-antimony-polymetallic assemblages. Antimonious mineral assemblages were most abundant in the southwest of the ore field.

The article considers the stages of mineralization of the Agyurt gold-copper-molybdenum deposit of the Lesser Caucasus. The following mineralization stages were established at the field: 1) quartz-molybdenum; 2) quartz-pyrite-chalcopyrite with gold; 3) quartz-carbonate-sphalerite; 4) quartz-carbonate. Gold ore bodies are mainly composed of aggregates of the second stage of mineralization, which is productive. Its mineral substance is represented by three paragenetic associations: 1) quartz-pyrite; 2) calcite-chalcopyrite-marcasite; 3) gold-telluride-bismuth. Chemical analyzes of pyrites, bismuthin, tellurium bismuthite are given. It has been found that native gold is found in the form of small, simple forms of gold in grains of early pyrite. In veins of chalcopyrite and grains of pyrite, it is usually confined to the marginal parts. The largest amount of gold is in close intergrowth with tellurium-bismuth minerals. It was found that the ore deposition environment (mineral composition, chemistry and structural and texture features of the host rocks) played a decisive role for various types of mineralization. It is established that, in the plan, the Agyurt deposit is localized in the contour of a rock block elongated in the northwest (submeridional) direction, bounded by tectonic zones from the north-north-west and north-east, which also bear a certain imprint of the formation of the structural plan of the ore field with near latitudinal strike of tectonic elements. These structures are most tectonically prepared for the localization of gold-copper-molybdenum mineralization (updated in the pre-ore stages and most permeable for hydrothermal structures), and were the main ore-supplying and ore-locating structural elements. The ore zones represented by hydrothermal-metasomatic formations, as well as quartz veins piercing them and numerous veinlets and sometimes mineralized dykes, are controlled by the Main Ordubad longitudinal (280°∠70–80°NE) and Agyurt-Misdag transverse (40–50°∠70° NE) with discontinuous violations and adjoin the hanging side (northeast flank) of the first. The combination of structural and petrogenetic factors not only predetermined the formation of deposits of the Agyurt type, but also determined the horizontal and vertical zonation of mineralization: an increase in the Mo content and a decrease in Cu with depth are established. The same pattern is observed in the horizontal direction: as you move away from the intrusive massif and the ore-removing channel, there is a transition from Cu-Mo-mineralization to copper and then polymetallic, i.e. the role of Cu increases, then Pb and Zn. The horizontal zoning in Agyurt is expressed in an increase in Au content and the total amount of sulfides with distance from the Main Ordubad Fault, and vertical shows an increase in Au content and decreases in Ag with depth.

Ores of the Vasilkovsky deposit include arsenopyrite, pyrite, pyrrhotite, marcasite, gold, chalcopyrite, sphalerite, galena, faded ore (tennantite)S, bismuthine, native bismuth, lellingite, molybdenite, cubanite, bornite, antimonite, relict minerals, magnetite, apatite and apatite chromite, sericite, chlorite, potassium feldspar, tourmaline), quartz, carbonates (siderite, ankerite, calcite), fluorite, barite. Arsenopyrite is the main ore mineral. It contains the bulk of gold, as well as impurities - copper, cobalt, nickel, bismuth, zirconium, titanium, lead, zinc, antimony, silver, molybdenum. Bismuth and its minerals are widespread, they are constantly associated with arsenopyrite, forming intergrowths with native gold, less often with chalcopyrite and faded ore. Native gold is distributed very unevenly, forms the finest precipitates ranging in size from tenths of a micron to 0.063 mm, grows together with quartz, arsenopyrite, pyrite and bismuth minerals. Rich ores were formed by combining bismuthcontaining associations with arsenopyrite. The role of gold in arsenopyrite increases with depth. Ores are of the gold-quartz-sulfide type. Quartz in ore up to 90 %, sulfides from 3 to 5 %. The content of harmful impurities (arsenic) reaches 2 % or more. Ores are refractory, require special technology for the beneficiation and extraction of gold.

Research subject. The mineral compositions of titanomagnetitic (apatite, titanomagnetite) and copper-titanomagnetitic (bornite, chalcopyrite, apatite, titanomagnetite) ores of the Volkovskoe Cu-Fe-Ti-V deposit (Middle Urals, Russia).Methods. The research was carried out using a Jeol JSM-6390LV scanning electron microscope and X-ray spectral microanalyzers JXA-5 (Jeol) at the Geoanalitik Collective Use Center of the IGG UB RAS. Results and conclusions.Native gold (with ≤ 0.3 wt % Pd, 0.2–0.4 wt % Cu; fneness 800–914 ‰), tellurides of Pd, Au and Ag (merenskyite, keithconnite, sylvanite, hessite) and Pt arsenide (sperrylite) were found in the copper-titanomagnetitic ores. For the frst time, two generations of native gold (fneness 1000 and 850–860 ‰) and palladium telluride (keithconnite Pd3-xTe) were detected in titanomagnetitic ores. The sequence of ore mineral formation and the features of their genesis were revealed. Native gold (fneness 1000‰) in the form of microinclusions in titanomagnetite was attributed to the magmatic stage. Noble metal minerals, intergrown with copper sulfdes (bornite, chalcopyrite, digenite) and associated with late hydroxyl-bearing minerals (amphibole, epidote, chlorite), are superimposed in relation to the magmatic minerals (pyroxene, plagioclase, hornblende, apatite, titanomagnetite, ilmenite, etc.) of these ores. Merenskyite, sperrylite, high fneness gold (800–914 ‰), as well as carrolite, cobaltite, copper-cobalt telluride and bismuth tellurium-selenide kawazulite Вi2Te2Se are syngenetic with copper sulfdes. The Au-Ag tellurides were deposited later than these minerals. It is shown that the high fugacity of tellurium, which binds Pd, Au, and Ag into tellurides, prevents the occurrence of native gold containing high concentrations of palladium and silver.

Abstract The ongoing global transition to low- and zero-CO2 energy generation and transport will require more raw materials and metals than ever produced before in human history to develop the necessary infrastructure for solar and wind power generation, electric power grid distribution, and electric vehicle componentry, including batteries. In addition to numerous critical elements, this transition will also require increased production of a range of other metals. This includes copper, with increased production of this metal providing the minerals industry with enhanced opportunities to secure the additional supply of associated or potential by-product elements. These include tellurium, selenium, bismuth, and antimony (among others), some of which are already predominantly produced as by-products from copper anode slimes. This study examines the geologic origins of over 240 active copper mines and over 200 electrolytic and electrowinning copper refineries worldwide. Although porphyry copper deposits dominate the copper supply trend, significant amounts of copper are supplied from the mining of sediment-hosted, massive sulfide, volcanogenic massive sulfide (VMS), and iron oxide-copper-gold (IOCG) mineral deposits. We integrate sources of copper concentrate with publicly available operational data for 32 copper electrorefineries to evaluate the geologic controls on the by-product supply potential of tellurium, selenium, bismuth, and antimony from copper anode slimes. These data represent some 32% of worldwide copper refineries and indicate that electrolytic refining of copper has the potential to supply ~777 t/yr tellurium, ~4,180 t/yr selenium, ~1,497 t/yr antimony, and 1,632 t/yr bismuth if 100% recovery of the by-product critical element proxies outlined in this study could be achieved. This is compared to current global production of ~490, ~2,900, ~153,000, and ~17,000 t/yr from all sources (rather than just copper by-products), respectively. Our analysis shows that there is no correlation between by-product potential and the amount of refined copper cathode production per year, but instead, the geologic origin of the copper concentrates is the key control on refinery by-product potential. This is exemplified by the fact that copper anode slimes derived from concentrates sourced from magmatic sulfide and VMS orebodies have an order of magnitude higher tellurium concentrations than those derived from porphyry deposits, reflecting the different abundances of tellurium within these mineral systems. These results are not surprising but demonstrate the possibilities for the development of robust proxies for by-product critical element supply potential using downstream data from copper (and potentially other base and precious metal) refineries. Equally significant, this study demonstrates the importance of downstream-up assessments of critical element potential as a complement to the more typical upstream-down deportment analyses undertaken to date. Finally, this type of approach allows the more accurate targeting of key parts of the metal supply chain with the capacity to increase by-product critical element production, rather than diluted or scattered approaches that assume that by-product metals are derived from one or two mineral deposit types (e.g., porphyry systems for the copper sector).

The paper presents the frst data on the distribution and composition of copper-noble metal mineralization in gabbroids of the Kumba intrusive (North Urals). The noble metal mineralization is associated with digenite-bornite, bornite-chalcopyrite, and pyrite-chalcopyrite ores and mainly occur minerals of precious metals. Nine noble metal mineral species are found for the frst time in amphibole and amphibole-olivine gabbro of the Kumba intrusive: native gold, Au-Ag alloys, Au, Ag, and Pd tellurides (hessite, merenskiite), Bi tellurides (kotulskite), antimonide-arsenides (isomertieite), arsenides (arsenopalladinite, sperrilite), and stannides (atokite) of Pt and Pd. Noble metal minerals from all sulfde assemblages in heavy concentrates are often accompanied by antimonides (stibnite) and Bi mineralization represented mainly by native bismuth and bismuthinite and less common sulfotellurides (baksanite) and tellurides (tsumoite). Our results make it possible to estimate the prospects of the discovery of new copper-noble metal deposits hosted in gabbro of the Uralian Platinum Belt. Taking into account the principles of occurrence of noble metal and copper mineralization, most gabbro intrusives of the Uralian Platinum Belt can be considered the promising objects for large-tonnage copper deposits with associated ore Au and Pd grades.

The Morrison deposit, located in Sudbury Mining Camp, produces ore containing copper, nickel, platinum, palladium and gold. Chalcopyrite dominates the mineral assemblage, while the main Ni-bearing phases are pentlandite and millerite. Cubanite, mackinawite, pyrrhotite, magnetite, sphalerite and galena are present too. Bornite is the main mineral in the peripheral parts of veins, often containing native silver veinlets. Platinum occurs as discrete PGM minerals: composite grains of moncheite (PtTe2) with hessite (Ag2Te); maslovite (PtBiTe) and sperrylite (PtAs2) are rare. Palladium can occur as a substitution in pentlandite and as discrete PGM minerals: michenerite (PdBiTe) and paolovite (Pd2Sn). Tellurides and bismuth-tellurides often display Pt-Pd and Bi-Te substitutions. Gold is present as a native element and as electrum. A zonation in the occurrence of elements can be explained by fractional crystallization of magmatic sulphides. There is a possibility of partial remobilization of precious metals (especially gold and palladium) by later hydrothermal and/or metamorphic processes with associated authigenic quartz, silicates (epidote, amphiboles) and secondary magnetite containing sulphide inclusions.

Abstract The Wombat Hole Prospect is a small copper–bismuth–(tellurium) exoskarn cropping out in the Morass Creek gorge, near Benambra, in eastern Victoria, Australia. Its main primary sulfide constituent is bornite in a grossular‒vesuvianite matrix. The skarn formed in a megaclast of Lower Silurian limestone from metal-bearing fluids accompanying the high-level emplacement of the Late Silurian–Lower Devonian Silver Flat Porphyry. Though the primary bornite mineralisation has been nearly obliterated by weathering, there are small relict patches containing exsolved grains of wittichenite (Cu3BiS3) and chalcopyrite, as well as inclusions of bismuth tellurides in the tetradymite group, namely sulphotsumoite (Bi3Te2S) and hedleyite (Bi7Te3). Joséite-A (Bi4TeS2), a mineral with a formula Bi3(Te,S)4, several unnamed Cu–Bi‒Te phases and minute grains of native bismuth have also been detected. Pervasive veining by chrysocolla throughout the garnet‒vesuvianite host contains a range of unusual secondary bismuth minerals that have crystallised at various times. These include mrázekite, namibite, pucherite, schumacherite and eulytine. Other secondary minerals present include wulfenite, bismutite, azurite, malachite and a poorly-crystalline bismuth oxide containing several weight percent tellurium. Rare grains of gold (electrum) containing up to 23 wt.% Ag are also present. The assemblage of grossular–vesuvianite with minor diopside is indicative of formation in a low- ${\rm X}_{{\rm C}{\rm O}_ 2}$ environment under fluid-buffered conditions. A temperature range between ~650°C and as low as ~150°C can be estimated from the exsolution of wittichenite and chalcopyrite from the bornite. The tetradymite-group inclusions formed first under low values of $f_{{\rm S}_ 2}$ / $f_{{\rm T}{\rm e}_ 2}$ , with bornite crystallising as values increased. The primary Cu‒Bi‒Te mineralogy and the unusual secondary mineral assemblage makes the Wombat Hole skarn unique in southeastern Australia. The deposit provides scope for studying the mobility of elements such as Bi and Te over short distances during weathering of hypogene ore minerals.

The Au-Cu-Bi- deposits of the Proterozoic Tennant Creek Inlier share geological and geochemical characteristics that indicate strong links in their genesis, yet the diversity in alteration assemblages, metal ratios and zonation patterns reflect variations in ore forming processes that previously have not been explained in detail. The West Peko deposit is representative of Cu-rich, pyrrhotite-bearing mineralisation with intermediate gold grades, in magnetite+ hematite-rich syntectonic ‘ironstones’. By contrast, the high grade Eldorado Au deposit contains minor sulfides and very low Cu grades, similar to several of the larger gold producers in the field (e.g. Juno, White Devil, Nobles Nob), and is also hematite-rich. Au, Chalcopyrite and Bi-sulfosalts were introduced into pre-existing ironside during progressive shearing, either late in the first regional deformation event (D1) or during a second phase of deformation. The occurrence of some Au zones outside ironstones suggests the ore fluids in part followed different flow paths to hose of the ironside-forming fluids. Three chemically and isotopically distinct fluids have been characterised. (i) Ironstone-forming fluids at West Peko and Eldorado were Ca-Na-Cl (-Fe?) brines containing 12-20 weight % total dissolved salts, and reached temperatures of 350-400°C during magnetite deposition. Oxygen and hydrogen isotope compositions of minerals formed at the ironside stage are consistent with an origin of ironstones from formation or metamorphic waters. (ii) The inferred Au-Bi+Cu transport fluid in he Cu- and sulphide-rich West Peko deposit was of low to moderate salinity (3-10 eq. wt. % Na Cl), ~300-350°C and N2 + CH4 – rich. Newly represented phase equilibria among the Fe-silicates stilpnomelane and minnesotaite, chlorite, biotite, sulfides, oxides and carbonates as well as fluid inclusion vapour compositions indicate that the Au-Bi+Cu transport fluid was relatively reducing with near-neutral pH and total dissolved sulphur contents of 0.001m to 0.01m. In the Eldorado Deeps Au- and hematite-rich deposit the Au-transporting fluid also may have been of low-moderate salinity, with Au deposition occurring at ~300°C. The reducing Au-Bi+Cu transport fluid at West Peko resembles primary magmatic or metamorphic water in oxygen and hydrogen isotopic composition. Carbon isotope ratios of Au-sulfide stage carbonates at West Peko point to involvement f organic carbon, probably sourced outside the host Warramunga Formation. (iii) A regionally distributed, oxidising Ca-Na-Cl brine with 20-35 weight percent total dissolved salts, was present prior to, after and probably during ore deposition. Mixing with lower salinity reducing Au-Bi+Cu transport fluid is inferred at West Peko and us suggested to have caused effervescence of N2+CH4 by ‘salting out’, relatively late in the Au depositional stage. An hypothesis of metal transport and deposition is proposed for the Tennant Creek deposits in which gold, copper and bismuth were transported in a reducing fluid and were deposited in the Cu- and sulphide-rich deposits dominantly by oxidation, desulfidation and initial pH increase as the reducing fluid reacted with magnetite+hematite ironstone. Mass transfer modelling indicates that relatively small amounts of ironstone are required to precipitate Au + Bi-sulfides, such as Eldorado, the oxidising brine may have played a significant role in ore deposition either by mixing with a reducing Au-Cu-Bi-transporting fluid, or by producing hematite oxidant additional to any already present in the ironstones. The greater extent of oxidation of the ore fluid in such deposits may have generally prevented saturation of copper minerals, resulting in low Cu grades. Gold is inferred to have been transported dominantly as uncharged bisulfide complexes, although biselenide complexes were potentially important. New thermodynamic data estimated for bismuth complexes are consistent with bismuth transport as uncharged S-H-O-bearing species in the Tenant Creek ore fluids. The existence of high grade Au-Bi deposits outside ironstones is predicted by chemical modelling of mixing between reducing and oxidising fluids, located where structures allowed focused flow of both fluids.