TY - JOUR

T1 - Noble metal speciations in hydrothermal sulphides

AU - Vikentyev, Ilya

AU - Vikent’eva, Olga

AU - Tyukova, Eugenia

AU - Nikolsky, Maximilian

AU - Ivanova, Julia

AU - Sidorova, Nina

AU - Tonkacheev, Dmitry

AU - Abramova, Vera

AU - Blokov, Vyacheslav

AU - Spirina, Adelina

AU - Borisova, Diana

AU - Palyanova, Galina

N1 - Funding Information: An experimental study of concentration mechanisms of NM in base metal sulphides was conducted in the frame of the Russian Scientific Foundation grant No. 14–17-00693 “Distribution and structural-chemical state of noble metals in sulphides through the ore deposits from magmatic to hydrothermal as an indicator of the conditions of mineralisation” (2014–2018), led by the first author. As a result of work on the sources of synchrotron radiation measurement, X-ray absorption spectra (XANES/EXAFS) and interpretation of the resulting data, and using X-ray photoelectron spectroscopy, the position of gold in the structure of sulphides was revealed. Main results were published in a series of papers devoted to Au in covellite CuS [16,17], in Fe-S and Fe-As-S minerals [19,52], in sphalerite (e.g., [92]), Au, Ag, Pt and Pd in pyrite and pyrrhotite [91], Pt in pyrite [22] and pyrrhotite [23]. Funding Information: Funding: This study began with the support of the Russian Scientific Foundation grant No. 14–17-00693 (2014–2018—methodological approach, synthesis of Au/Ag-doped sulphides), and the Ministry of Science and Higher Education of the Russian Federation (field work, sampling, XRD and INAA study) and the Russian Foundation for Basic Research, projects No. 18–05-70041 (deposits of the Polar and North Urals; field work, sampling, SEM/EDS and LA-ICPMS study) and No. 20–05-00849 (ore deposits of the Middle and South Urals; field work, sampling, EPMA, SEM/EDS and LA-ICPMS study) funded this research. The present study contains parts of the PhD Theses of V.B., D.T., N.S., A.S. and D.B. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/5

Y1 - 2021/5

N2 - A significant part of the primary gold reserves in the world is contained in sulphide ores, many types of which are refractory in gold processing. The deposits of refractory sulphide ores will be the main potential source of gold production in the future. The refractory gold and silver in sulphide ores can be associated with micro-and nano-sized inclusions of Au and Ag minerals as well as isomorphous, adsorbed and other species of noble metals (NM) not thoroughly investigated. For gold and gold-bearing deposits of the Urals, distribution and forms of NM were studied in base metal sulphides by laser ablation-inductively coupled plasma mass spectrometry and by neutron activation analysis. Composition of arsenopyrite and As-pyrite, proper Au and Ag minerals were identified using electron probe microanalysis. The ratio of various forms of invisible gold—which includes nanoparticles and chemically bound gold—in sulphides is discussed. Observations were also performed on about 120 synthetic crystals of NM-doped sphalerite and greenockite. In VMS ores with increasing metamorphism, CAu and CAg in the major sulphides (sphalerite, chalcopyrite, pyrite) generally decrease. A portion of invisible gold also decreases —from ~65–85% to ~35–60% of the total Au. As a result of recrystallisation of ores, the invisible gold is enlarged and passes into the visible state as native gold, Au-Ag tellurides and sulphides. In the gold deposits of the Urals, the portion of invisible gold is usually <30% of the bulk Au.

AB - A significant part of the primary gold reserves in the world is contained in sulphide ores, many types of which are refractory in gold processing. The deposits of refractory sulphide ores will be the main potential source of gold production in the future. The refractory gold and silver in sulphide ores can be associated with micro-and nano-sized inclusions of Au and Ag minerals as well as isomorphous, adsorbed and other species of noble metals (NM) not thoroughly investigated. For gold and gold-bearing deposits of the Urals, distribution and forms of NM were studied in base metal sulphides by laser ablation-inductively coupled plasma mass spectrometry and by neutron activation analysis. Composition of arsenopyrite and As-pyrite, proper Au and Ag minerals were identified using electron probe microanalysis. The ratio of various forms of invisible gold—which includes nanoparticles and chemically bound gold—in sulphides is discussed. Observations were also performed on about 120 synthetic crystals of NM-doped sphalerite and greenockite. In VMS ores with increasing metamorphism, CAu and CAg in the major sulphides (sphalerite, chalcopyrite, pyrite) generally decrease. A portion of invisible gold also decreases —from ~65–85% to ~35–60% of the total Au. As a result of recrystallisation of ores, the invisible gold is enlarged and passes into the visible state as native gold, Au-Ag tellurides and sulphides. In the gold deposits of the Urals, the portion of invisible gold is usually <30% of the bulk Au.

KW - Gold deposits

KW - Invisible gold

KW - LA-ICPMS

KW - Sulphides

KW - Synthesis

KW - Urals

KW - VMS deposits

UR - http://www.scopus.com/inward/record.url?scp=85104969654&partnerID=8YFLogxK

U2 - 10.3390/min11050488

DO - 10.3390/min11050488

M3 - Review article

AN - SCOPUS:85104969654

VL - 11

JO - Minerals

JF - Minerals

SN - 2075-163X

IS - 5

M1 - 488

ER -