This study comprises the relationship between organic matter(OM)and gold occurrence using two distinctive ore deposits of the Bakyrchik gold-sulfide deposit(Kazakhstan)and Western Mecsek uranium ore deposit(Hungary).T...This study comprises the relationship between organic matter(OM)and gold occurrence using two distinctive ore deposits of the Bakyrchik gold-sulfide deposit(Kazakhstan)and Western Mecsek uranium ore deposit(Hungary).The two ore deposits are identified as organicrich sedimentary formations linked to the Variscan gold cycle globally.Characterizing OM is essential because it can act as a carrier for gold,influencing its distribution and behavior within the deposit.Understanding the nature and distribution of OM can provide insights into the processes of gold deposition and help optimize exploration and extraction strategies in mining operations.The primary objective is to characterize OM by identifying its elemental composition,thermal maturity,functional groups,and soluble fractions;and extract gold from OM using a two-step sequential extraction method(hydrogen peroxide and aqua regia)combined with geochemical techniques.Analytical and experimental results from samples of both ore deposits indicate the presence of finely disseminated solid bitumen and reworked vitrinite,originating from thermally matured(RmcRo%—3.76 in Bakyrchik;Ro%—2.25 in W-Mecsek)terrigenous high plants.Both deposits exhibit extremely low extractable bitumen yield and TOC(0.34%in Bakyrchik;0.25 wt%in W-Mecsek),characterized by an aromatic carboxylic acid organic structure and a composition rich in sulfur-containing(1.17%in Bakyrchik;5.81%in W-Mecsek)aromatic hydrocarbons.Gold occurrence and enrichment within OM were confi rmed through the sequential extraction method employing ICP-OES and LA-ICP-MS techniques.The sequentially extracted gold content from OM reached up to 3 ppm in Bakyrchik and up to 3.28 ppm in Western Mecsek,accompanied by Ag(ranging from 0.01 to 0.32 ppm).Higher concentrations of Au(4 ppm)and Ag(27 ppm)were extracted from residue materials,which are likely associated with sulfide minerals.The presence of gold in OM was further validated using LA-ICP-MS.Gold bonding within OM structure,gold is preserved in the form of lattice gold or structurally bonded metal most likely within the aromatic hydrocarbon fractions of the OM in both the W-Mecsek and Bakyrchik deposits.These findings underscore the profound potential of ongoing exploration endeavors,off ering pivotal revelations regarding the extraction and practical application of Au and Ag derived from OM within the geochemical framework of both ore deposits.展开更多
The paper comprises new analytical data on the nature and occurrence of gold in solid pyrobitumen,closely associated with the main gold-bearing sulfide arsenic ores of the Bakyrchik gold deposit(Kazakhstan),related to...The paper comprises new analytical data on the nature and occurrence of gold in solid pyrobitumen,closely associated with the main gold-bearing sulfide arsenic ores of the Bakyrchik gold deposit(Kazakhstan),related to post-collisional magmatic-hydrothermal origin.Gold mineralization of the deposit occurs mainly in the form of an“invisible”type of gold in the structures of arsenian pyrite and arsenopyrite,and the form of gold-organic compounds of pyrobitumen in carbonaceous-terrigenous sequences of Carboniferous formation.Microscopic and electron microscopic analysis,Raman and FT-Infrared analysis,mineralogical and three-step sequential extraction analysis(NH2OHHCl,H2O2,HNO3?HCl)has been carried out using 9 ore samples(from 3 different types of ores)for a comprehensive study of pyrobitumen and sulfide arsenic ores focusing mainly on organic matter.The sequentially extracted precious metal content of pyrobitumen reaches up to 7 ppm gold and other metals like Ag 4 ppm,Pt 31 ppb,and Pd 26 ppb,forming metal–organic compounds,while arsenic sulfide minerals incorporate 11 ppm gold,39 ppm Ag,0.49 ppm Pt.The enrichment of gold associating with organic matter and sulfide ore minerals was confirmed in this study.Organic matter was active in the migration of gold and the capture of gold by pyrobitumen.Moreover,the reductive organic matter agent released gold,most likely for the sulfide arsenic ore minerals.Pyrobitumen was a decisive factor in the concentration,transportation,and preservation of gold in the deposit.展开更多
基金Social Policy Grant(064.01.00 SPG)financed by Nazarbayev University,Kazakhstan。
文摘This study comprises the relationship between organic matter(OM)and gold occurrence using two distinctive ore deposits of the Bakyrchik gold-sulfide deposit(Kazakhstan)and Western Mecsek uranium ore deposit(Hungary).The two ore deposits are identified as organicrich sedimentary formations linked to the Variscan gold cycle globally.Characterizing OM is essential because it can act as a carrier for gold,influencing its distribution and behavior within the deposit.Understanding the nature and distribution of OM can provide insights into the processes of gold deposition and help optimize exploration and extraction strategies in mining operations.The primary objective is to characterize OM by identifying its elemental composition,thermal maturity,functional groups,and soluble fractions;and extract gold from OM using a two-step sequential extraction method(hydrogen peroxide and aqua regia)combined with geochemical techniques.Analytical and experimental results from samples of both ore deposits indicate the presence of finely disseminated solid bitumen and reworked vitrinite,originating from thermally matured(RmcRo%—3.76 in Bakyrchik;Ro%—2.25 in W-Mecsek)terrigenous high plants.Both deposits exhibit extremely low extractable bitumen yield and TOC(0.34%in Bakyrchik;0.25 wt%in W-Mecsek),characterized by an aromatic carboxylic acid organic structure and a composition rich in sulfur-containing(1.17%in Bakyrchik;5.81%in W-Mecsek)aromatic hydrocarbons.Gold occurrence and enrichment within OM were confi rmed through the sequential extraction method employing ICP-OES and LA-ICP-MS techniques.The sequentially extracted gold content from OM reached up to 3 ppm in Bakyrchik and up to 3.28 ppm in Western Mecsek,accompanied by Ag(ranging from 0.01 to 0.32 ppm).Higher concentrations of Au(4 ppm)and Ag(27 ppm)were extracted from residue materials,which are likely associated with sulfide minerals.The presence of gold in OM was further validated using LA-ICP-MS.Gold bonding within OM structure,gold is preserved in the form of lattice gold or structurally bonded metal most likely within the aromatic hydrocarbon fractions of the OM in both the W-Mecsek and Bakyrchik deposits.These findings underscore the profound potential of ongoing exploration endeavors,off ering pivotal revelations regarding the extraction and practical application of Au and Ag derived from OM within the geochemical framework of both ore deposits.
基金Open access funding provided by University of Miskolc.“Improved exploitation and utilization of subsurface natural resources”(TUDFO/51757–1/2019-ITM)Thematic Excellence Program of the University of Miskolc,financed by the National Research,Development and Innovation Office of Hungary+1 种基金Sustainable Raw Materials Management Thematic Network—RING 2017,EFOP-3.6.2–2017-00010 project in the framework of the Széchenyi 2020 Programsupported by the European Union,co-financed by the European Social Fund.
文摘The paper comprises new analytical data on the nature and occurrence of gold in solid pyrobitumen,closely associated with the main gold-bearing sulfide arsenic ores of the Bakyrchik gold deposit(Kazakhstan),related to post-collisional magmatic-hydrothermal origin.Gold mineralization of the deposit occurs mainly in the form of an“invisible”type of gold in the structures of arsenian pyrite and arsenopyrite,and the form of gold-organic compounds of pyrobitumen in carbonaceous-terrigenous sequences of Carboniferous formation.Microscopic and electron microscopic analysis,Raman and FT-Infrared analysis,mineralogical and three-step sequential extraction analysis(NH2OHHCl,H2O2,HNO3?HCl)has been carried out using 9 ore samples(from 3 different types of ores)for a comprehensive study of pyrobitumen and sulfide arsenic ores focusing mainly on organic matter.The sequentially extracted precious metal content of pyrobitumen reaches up to 7 ppm gold and other metals like Ag 4 ppm,Pt 31 ppb,and Pd 26 ppb,forming metal–organic compounds,while arsenic sulfide minerals incorporate 11 ppm gold,39 ppm Ag,0.49 ppm Pt.The enrichment of gold associating with organic matter and sulfide ore minerals was confirmed in this study.Organic matter was active in the migration of gold and the capture of gold by pyrobitumen.Moreover,the reductive organic matter agent released gold,most likely for the sulfide arsenic ore minerals.Pyrobitumen was a decisive factor in the concentration,transportation,and preservation of gold in the deposit.
