scholarly journals Matter-mineral characteristics of technogene placers – potential sources of precious metals (on the example of the Nizhneselemdzhinsky gold-bearing node of Priamurye, Russia)

Georesursy ◽  
2019 ◽  
Vol 21 (1) ◽  
pp. 2-14 ◽  
Author(s):  
Inna V. Kuznetsova ◽  
Petr P. Safronov ◽  
Natalya V. Moiseenko
Keyword(s):  
Precious Metal ◽  
Native Gold ◽  
Precious Metals ◽  
High Standard ◽  
Metallic Lead ◽  
Additional Information ◽  
Mineral Characteristics ◽  
Nano Gold ◽  
Spoil Heaps ◽  
Gold Bearing

Over tens of years of mining and processing of ores and placers of gold in the world a huge amount of wastes originated in the form of spoil heaps and tailing dumps, in which the content of valuable components allow them to be considered a real additional resource of precious metals. The aim of the work was to establish the changes that took place in time in the spoil heaps of gold mining and to determine the prospects of the technogene placers as a potential source of the precious metal. The investigations were carried out with the use of the methods of the analytical raster electron microscopy and mineralogical and atomic-absorption analyses. On the example of the Nizhneselemdzhinsky gold-bearing node of Priamurye we have done the compatative analysis of the mineral and granulometric composition of the original and developed placers. It is shown that through the technogenesis the mineral composition of the deposits changes including the process of decomposition of the lead and iron minerals with a partial reduction to a native metal. In addition to the native gold in the technogene placers there have been found the following minerals with a high content of the precious metal: rutile, monazite, magnetite, metallic lead, galena, ilmenite, and zircon. The content of free gold in dumps is 190 mg/m3 in the average. The main amount of it (about 83%) consists of the fine gold (< 0.5 mm). We have studied the chemical composition of the native gold and associated rocks. It has been established that the gold has a multiphase composition. The phases are for the most part the gold amalgams and have two-, three-, and four-component compositions (Au-Hg, Au-Ag-Hg, Au-Hg-Pb, Au-Ag-Hg-Pb). About 30% of gold of the technogene placers have a high standard of fineness (~980‰). Almost all native gold is in close intergrowths with the rock-forming matrix of different composition: hydroalumosilicates, oxides, and hydroxides of Fe, Mn, and Pb, highly carbonaceous and carbon-bearing formations, and so on. Under the action of the physicochemical and biochemical process in the technogene placers different transformations of the native gold take place: purification at the expense of the silver evacuation; decomposition of the minerals-concentrators of gold; precipitation of micro- and nano-gold at the geochemical barriers with the formation of the so-called “new” gold (from nanoformations to micro- and macroforms). Through the operation of the technogene placers one should take into account the fact that the ore minerals in them have high concentrations of heavy metals and radioactive elements, and the gold has a complicated multiphase and multicomponent composition, and ¾ of it is amalgamated. The data obtained give the additional information for the elaboration of technologies for the development of the prospective gold-bearing technogene placers.

scholarly journals Genesis of Precious Metal Mineralization in Intrusions of Ultramafic, Alkaline Rocks and Carbonatites in the North of the Siberian Platform

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 354
Author(s):  
Anatoly M. Sazonov ◽  
Aleksei E. Romanovsky ◽  
Igor F. Gertner ◽  
Elena A. Zvyagina ◽  
Tatyana S. Krasnova ◽  
...  
Keyword(s):  
High Temperature ◽  
Siberian Platform ◽  
Precious Metal ◽  
Native Gold ◽  
Precious Metals ◽  
Ore Formation ◽  
Central Type ◽  
Alkaline Rocks ◽  
The North ◽  
Pge Mineralization

The gold and platinum-group elements (PGE) mineralization of the Guli and Kresty intrusions was formed in the process of polyphase magmatism of the central type during the Permian and Triassic age. It is suggested that native osmium and iridium crystal nuclei were formed in the mantle at earlier high-temperature events of magma generation of the mantle substratum in the interval of 765–545 Ma and were brought by meimechite melts to the area of development of magmatic bodies. The pulsating magmatism of the later phases assisted in particle enlargement. Native gold was crystallized at a temperature of 415–200 °C at the hydrothermal-metasomatic stages of the meimechite, melilite, foidolite and carbonatite magmatism. The association of minerals of precious metals with oily, resinous and asphaltene bitumen testifies to the genetic relation of the mineralization to carbonaceous metasomatism. Identifying the carbonaceous gold and platinoid ore formation associated genetically with the parental formation of ultramafic, alkaline rocks and carbonatites is suggested.

scholarly journals Precious metal mineralogy of the Murtykty gold deposit, South Urals

2019 ◽  
Vol 5 ◽  
pp. 57-68
Author(s):  
Yu .A. Paduchina ◽  
N.S. Chukhareva ◽  
K.A Novoselov ◽  
E.E. Palenova ◽  
E.V. Belogub ◽  
...  
Keyword(s):  
Gold Deposit ◽  
Precious Metal ◽  
Native Gold ◽  
Precious Metals ◽  
South Urals ◽  
Main Attention ◽  
Mode Of Occurrence ◽  
Ore Mineralogy

Ore mineralogy of the Murtykty gold deposit is presented in the paper and main attention is paid to the mode of occurrence of precious metals. Ores are pyrite-bearing quartz-chlorite (±sericite, ±carbonate of the dolomite-ankerite series) metasomatites with variable ratios between rock-forming minerals. Pyrite is the major sulfde; sphalerite, galena and chalcopyrite are secondary in abundance. Rare minerals include pyrrhotite, arsenopyrite, altaite, coloradoite, hessite, petzite, calaverite, volynskite, rucklidgeite, and native gold. The Ag content of native gold ranges from 6.11 to 35.32 wt. %. Signifcant amount of Au and Ag occurs in a telluride form: hessite Ag2Te, petzite Ag3AuTe2, calaverite AuTe2, and volynskite AgBiTe2. The refractory features of sulfde ores are caused by diverse modes of occurrences of precious metal.

Gold-bismuth-telluride-sulphide assemblages at the Viceroy Mine, Harare-Bindura-Shamva greenstone belt, Zimbabwe

2008 ◽  
Vol 72 (4) ◽  
pp. 953-970 ◽  
Author(s):  
T. Oberthür ◽  
T. W. Weiser
Keyword(s):  
Native Gold ◽  
Gold Mineralization ◽  
Close Association ◽  
Shear Zones ◽  
Gold Deposits ◽  
Orogenic Gold ◽  
Main Stage ◽  
Melting Temperatures ◽  
Native Bismuth ◽  
Gold Bearing

AbstractGold mineralization at the Viceroy Mine is hosted in extensional veins in steep shear zones that transect metabasalts of the Archaean Arcturus Formation. The gold mineralization is generally made up of banded or massive quartz carrying abundant coarse arsenopyrite. However, most striking is a distinct suite of Au-Bi-Te-S minerals, namely joseite-A (Bi4TeS2), joseite-B (Bi4Te2S), hedleyite (Bi7Te3), ikunolite (Bi4S3), ‘protojoseite’ (Bi3TeS), an unnamed mineral (Bi6Te2S), bismuthinite (Bi2S3), native Bi, native gold, maldonite (Au2Bi), and jonassonite (AuBi5S4). The majority of the Bi-Te-S phases is characterized by Bi/(Se+Te) ratios of >1. Accordingly, this assemblage formed at reduced conditions at relatively low fS2 and fTe2. Fluid-inclusion thermometry indicates depositional temperatures of the main stage of mineralization of up to 342°C, in the normal range of mesothermal, orogenic gold deposits worldwide. However, melting temperatures of Au-Bi-Te phases down to at least 235°C (assemblage (Au2Bi + Bi + Bi7Te3)) imply that the Au-Bi-Te phases have been present as liquids or melt droplets. Furthermore, the close association of native gold, native bismuth and other Bi-Te-S phases suggests that gold was scavenged from the hydrothermal fluids by Bi-Te-S liquids or melts. It is concluded that a liquid/melt-collecting mechanism was probably active at Viceroy Mine, where the distinct Au-Bi-Te-S assemblage either formed late as part of the main, arsenopyrite-dominated mineralization, or it represents a different mineralization event, related to rejuvenation of the shear system. In either case, some of the gold may have been extracted from pre-existing, gold-bearing arsenopyrite by Bi-Te-S melts, thus leading to an upgrade of the gold ores at Viceroy. The Au-Bi-Te-S assemblage represents an epithermal-style mineralization overprinted on an otherwise mesothermal (orogenic) gold mineralization.

STALE GOLD-BEARING TAILINGS OF THE BALEIZOLOTO PLANT AND THE PROBLEM OF THEIR DISPOSAL

2021 ◽  
Vol 27 (4) ◽  
pp. 45-54
Author(s):  
G. Yurgenson ◽  
◽  
L. Shumilova ◽  
А. Khatkova ◽  
◽  
...  
Keyword(s):  
Negative Impact ◽  
Chemical Elements ◽  
Raw Materials ◽  
Precious Metals ◽  
Gold Content ◽  
Residential Areas ◽  
Extraction Technology ◽  
Useful Components ◽  
Technogenic Raw Materials ◽  
Gold Bearing

The relevance of the research is the need to recultivate the waste from the enrichment of gold-bearing ores that lie in the immediate vicinity of the residential areas of Baley city, which have a negative impact on the environmental situation in it, as well as to develop a technological approach to the extraction of gold and silver. The purpose of the study is to study the material composition and develop a technology for extracting precious metals. The object of the study is the stale tailings of the ZIF-1 plant “Baleizoloto”. The subject of the study is mineral composition of stale tailings, content of useful components and their extraction technology, the method and methodology presented by mineralogical and chemical analyses of enrichment tailings. Results. The analysis of the tailings dumps’ state of the gold recovery factories of the Baleizoloto plant was carried out. The contents of gold and other chemical elements, among which arsenic, zinc, copper, antimony, and lead predominate, were determined. The gold content prevails in the stale tailings of the ZIF-1 factory, which processed the ores of the Baley deposit, and is in the range of 1.09-1.37 g / t, on average – 1.17 g/t. This determines the prospects for their primary processing. The gold in the clay-sand fraction of the stale tailings is mainly found in thin accretions with quartz, carbonates, pyrite, arsenopyrite, sulfosols, and tellurides. The field of application is processing of technogenic raw materials. Conclusions. It was determined that the sizes of gold inclusions are in the range of 0.7-0.03 mm, the gold penetration varies from 63 to 91.15, and on average is 82.13; the main impurity in gold is silver with a content of 8.85-37%; the average silver content in the tailings of the ZIF-1 factory is 1.85 g/t; the recommended technological scheme for processing stale tailings of ZIF-1 of the Baleizoloto plant has been developed, including the following operations: photoelectron-activation preparation, pelletizing with active solution, heap leaching, two-stage sorption with bubbling with ozone

Variant Offset-Type Platinum Group Element Reef Mineralization in Basal Olivine Cumulates of the Kapalagulu Intrusion, Western Tanzania

2021 ◽  
Author(s):  
M. D. Prendergast
Keyword(s):  
Precious Metal ◽  
Platinum Group Element ◽  
Early Stage ◽  
Precious Metals ◽  
Parental Magma ◽  
Group Element ◽  
Metal Enrichment ◽  
Reef Development ◽  
Platinum Group ◽  
Olivine Cumulates

Abstract The Kapalagulu intrusion in eastern Tanzania hosts a major, 420-m-thick, stratiform/stratabound platinum group element (PGE)-bearing sulfide zone—the Lubalisi reef—within a prominent, chromititiferous, harzburgite unit close to its stratigraphic base. Several features of the vertical base and precious metal distributions (in a composite stratigraphic section based upon two deep exploration drill holes) display similarities to those of offset-type PGE reefs that formed under the overall control of Rayleigh fractionation: (1) composite layering (at several scales) defined by systematic vertical variations of sulfide and precious metal contents and intermetallic ratios, indicating repeated cycles of PGE enrichment and depletion in the order Pd-Pt-Au-Cu, and (2) in the lower part of the reef, stratigraphic offsets of the precious metal peaks below peak sulfide (Cu) content. The form and geochemistry of the reef are consistent with overturns of basal liquid layers within a liquid layering system (i.e., stable density-driven stratification of a magma chamber), plus at least two minor inputs of parental magma during which the resident magma was recharged with sulfur and metals, and the effective depletion of precious metals in the magma midway through reef development. The Lubalisi reef differs from classic offset-type PGE reefs, however, principally because individual Pd, Pt, and Au enrichment peaks are coincident, not offset. The reef is set apart from other offset-type PGE reefs in three additional ways: (1) its association with olivine cumulates that crystallized soon after initial magma emplacement and well below the first appearance of cumulus pyroxene or plagioclase (implying attainment of sulfide saturation and precious metal enrichment without prolonged concentration of sulfur and chalcophile metals by normal magma cooling and differentiation), (2) the probable role of chromite crystallization in not only triggering sulfide segregation during reef formation but also facilitating precious metal enrichment in the early stages of reef development, and (3) its great width. The early stage of fractionation may also help explain the coincident precious metal peaks through its effect on apparent precious metal partition coefficients.

INTENSIFICATION OF DISPERSED AND FINE-GRAINED SILVER EXTRACTION IN CYANIDE HEAP LEACHING OF GOLD

2020 ◽  
Vol 26 (8) ◽  
pp. 40-48
Author(s):  
Yu. Rubtsov ◽  
◽  
А. Trubachev ◽  
E. Voronov ◽  
A. Lavrov ◽  
...  
Keyword(s):  
Noble Metals ◽  
Ph Value ◽  
Chemical Activation ◽  
Precious Metals ◽  
Federal District ◽  
Heap Leaching ◽  
Sodium Cyanide ◽  
Cycle Duration ◽  
Mining Equipment ◽  
Gold Bearing

Since the cost of gold has increased by an order of magnitude over the past 20 years, gold mining began to be carried out from ores that are not previously acceptable for heap leaching (HL) technology – these are refractory ores with thin and ultrafine inclusions of precious metals, ore with an increased silver content. In the Russian Federation, classical representations in the field of gold and silver HL prevail in design solutions. At the same time, the problem of silver leaching is considered in terms of the associated extraction of the main component. This approach is determined by a limited set of technological measures that have become an integral part of the classic technological regulation: ore crushing to the class –200–40 mm, sodium cyanide consumption at the level of 0,5 kg/t; pH value – 10,5; cycle duration 65 days or more; gold concentration in production solutions – fractions, mg/l; using activated carbon for sorption of noble metals. Processing ores with silver contents of 30 g/t and a more classical approach to gold HL does not allow to increase the degree of extraction. There is a need to modernize the circuit or change the parameters of the technological regulations. The object of the study was a sample of poor quartz ore provided by the customer developing one of the gold and silver deposits of the Far Eastern Federal District, the object was to increase the degree of leaching of silver from poor gold-bearing ores without changing the technological scheme and without attracting additional mining equipment. Critical analysis of literary data was carried out and the main directions of gold production from poor gold-bearing ores were identified. Chemical and mineralogical compositions of silver-containing minerals and ore rocks were investigated. Forms of association of silver with ore minerals and rocks have been established. The option of physical and chemical activation of increase of reactivity of cyanide solutions during heap leaching of silver from poor gold-bearing ores is chosen. In laboratory conditions, it was found that an increase in the concentration of sodium cyanide by 6 times or more contributes to a satisfactory extraction of gold both in agitation and percolation leaching of silver. However, in the latter case, the positive result was obtained only with the use of solutions with increased reactivity

scholarly journals Editorial: Special Issue Catalysis by Precious Metals, Past and Future

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 247
Author(s):  
Svetlana Ivanova ◽  
Marcela Martínez Tejada
Keyword(s):  
Precious Metal ◽  
Precious Metals ◽  
Special Issue ◽  
Metal Catalysis ◽  
Editorial Special Issue ◽  
Precious Metal Catalysis

Precious metal catalysis is often synonymous with diversity and versatility [...]

Bulk Liquid for the Skaergaard Intrusion and Its PGE-Au Mineralization: Composition, Correlation, Liquid Line of Descent, and Timing of Sulphide Saturation and Silicate–Silicate Immiscibility

2019 ◽  
Vol 60 (10) ◽  
pp. 1853-1880 ◽  
Author(s):  
Troels F D Nielsen ◽  
C Kent Brooks ◽  
Jakob K Keiding
Keyword(s):  
Precious Metal ◽  
Bulk Composition ◽  
Precious Metals ◽  
Bulk Liquid ◽  
Skaergaard Intrusion ◽  
Liquid Line ◽  
Multi Stage ◽  
Silicate Liquids ◽  
Crystallization Zone ◽  
Liquid Line Of Descent

Abstract Preferred and modelled bulk composition of the Skaergaard intrusion are compared to coeval basaltic compositions in East Greenland and found to relate to the second evolved cycle of Geikie Plateau Formation lavas and coeval Skaergaard-like dikes in major and trace element (Mg# ∼45, Ce/Nb ∼2·5, (Dy/Yb)N ∼1·35), and precious metal composition (Pd/Pt ∼3, Au/Pt ∼2) as well as in age (∼56 Ma). Successful comparisons of precious metal compositions only occur with Skaergaard models based on mass balance. The bulk liquid of the intrusion evolved along the liquid line of descent to immiscibility between Si- and Fe-rich silicate liquids after ∼90% of crystallization (F = ∼0·10) in agreement with experimental constraints. Immiscibility led to accumulation and fractionation of the Fe-rich silicate melt in the mushy floor of the intrusion and continued accumulation of granophyre component in the remaining bulk liquid. The composition of plagioclase in the precious metal mineralized gabbro and modelling of Pd/Pt and Au/Pt in first formed droplets of sulphide melt suggest that sulphide saturation was reached in interstitial melts in crystal mushes in the floor and roof and in bulk liquid with a composition equivalent to that of the bulk liquid at lower UZa times and after crystallization of 82–85% of the bulk liquid (F = 0·19–0·16). Prior to sulphide saturation in UZa type melt, the precious metals ratios of the bulk liquid were controlled by the loss of Pt relative to Pd and Au in agreement with the low empirical and experimental solubility of Pt of ∼9ppb compared to a much higher value for Pd and Au. The relative timing between sulphide saturation (F = ∼0·18) and immiscibility between silicate melts (F = ∼0·10) and modelled precious metal ratios underpin the proposed multi-stage model for the mineralization, advocating initial accumulation in the mushy floor of the magma chamber controlled by sulphide saturation in mush melts rather than bulk melt, followed by redistribution of precious metals in a macro-rhythmic succession of gabbroic layers of the upward migrating crystallization zone.

The distribution of trace precious metals in minerals and mineral products

1992 ◽  
Vol 56 (384) ◽  
pp. 289-308 ◽  
Author(s):  
Louis J. Cabri
Keyword(s):  
Electron Microprobe ◽  
Analytical Methods ◽  
Precious Metal ◽  
Precious Metals ◽  
Analytical Techniques ◽  
Environmental Concerns ◽  
Ion Microprobe ◽  
Future Directions ◽  
Specific Analysis ◽  
Process Mineralogy

AbstractData on the distribution of the precious metals (Au, Ag and the platinum=group elements Ru, Rh, Pd, Os, Ir, Pt) are rapidly accumulating as a consequence of the application of microbeam analytical techniques such as the electron microprobe, the proton microprobe, and the ion microprobe. The new data obtained with these techniques build on knowledge accumulated over the last 140 years using bulk analytical methods (e.g. spectrographic). The nature of the occurrence, the concentrations, and the variation in amount s of precious metals in minerals and mineral products are reviewed with comments as to the significance of the results with respect to industrial and environmental concerns. Future directions in mineral-specific analysis of trace precious-metal concentrations and applications outside of process mineralogy are discussed.

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