The increasing atmospheric CO_(2)concentration linked to human activity results in global warming by the greenhouse effect.This anthropogenic CO_(2)may be sequestrated into geological formations,e.g.,porous basalts,sa...The increasing atmospheric CO_(2)concentration linked to human activity results in global warming by the greenhouse effect.This anthropogenic CO_(2)may be sequestrated into geological formations,e.g.,porous basalts,saline aquifers,depleted oil or gas reservoirs,and unmineable coal seams.Furthermore,carbon capture,utilization,and storage(CCUS)methods are an acceptable and sustainable technology to meet the goals of the Paris Agreement,in which Kazakhstan is expected to reduce greenhouse gas emissions by 25%compared with the 1990 level.Unmineable coal seams are an attractive option among all geostorage solutions,as CO_(2)sequestration in coal comes with an income stream via enhanced coalbed methane(ECBM)recovery.This paper identifies four carboniferous coal formations,namely Karagandy,Teniz-Korzhinkol,Ekibustuz,and Chu coal basins of Kazakhstan,as CO_(2)geostorage solutions for their unmineable coal seams.The ideal depth of CO_(2)storage is identified as 800 m to ensure the supercritical state of CO_(2).However,the Ekibustuz coal basin fails to meet the required depth of 800 m in its unmineable coal seams.The conventional formula for calculating CO_(2)storage in coal basins has been modified,and a new formula has been proposed for assessing the CO_(2)storage potential in a coal seam.The CO_(2)storage capacities of unmineable coal seam of these coal basins are 24.60 Bt,0.61 Bt,14.02 Bt,and 5.42 Bt,respectively.The Langmuir volume of the coal fields was calculated using the proximate analysis of coalfields and found to vary between 36.42 and 98.90 m3/ton.This paper is the first to outline CO_(2)storage potential in Kazakhstani coal basins,albeit with limited data,along with a detailed geological and paleographic review of the carboniferous coalfields of Kazakhstan.A short overview of the CO_(2)-ECBM process was also included in the paper.Instead of any experimental work for CO_(2)storage,this paper attempts to present the CO_(2)storage capacity of carboniferous coal formation using the modified version of previously determined formulas for CO_(2)storage.展开更多
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
The work concentrates on extraction of precious metals (Au, Ag, Pd, Pt) and As, Sb, Cu, Pb, Zn, and Fe which are bound to sulfide-ore minerals in sedimentary rocks, using a two-step sequential extraction experiment wi...The work concentrates on extraction of precious metals (Au, Ag, Pd, Pt) and As, Sb, Cu, Pb, Zn, and Fe which are bound to sulfide-ore minerals in sedimentary rocks, using a two-step sequential extraction experiment with two chemical reagents (hydrogen peroxide and aqua regia) on three rock specimens from the black shale formation in Bakyrchik gold-sulfide deposit in North-East Kazakhstan. The experiment allows to determine the speciation of hardly accessible precious metals and to identify the most productive ore-forming stage from the three identified ones. Analytical methods are used for determining polysulfide mineral textures (optical microscopy), mineralogical (XRPD) and chemical compositions (XRF), and for measuring extracted metals concentrations (ICP-OES) in experimental procedures. The analytical results show that the first stage is more productive in gold (total extraction 2.8 ppm) than others and the second stage is more productive in Ag (total 1.6 ppm) and Pd (total 0.01 ppm), while the last stage is more productive in Pt (0.019 ppm) in the deposit.展开更多
文摘The increasing atmospheric CO_(2)concentration linked to human activity results in global warming by the greenhouse effect.This anthropogenic CO_(2)may be sequestrated into geological formations,e.g.,porous basalts,saline aquifers,depleted oil or gas reservoirs,and unmineable coal seams.Furthermore,carbon capture,utilization,and storage(CCUS)methods are an acceptable and sustainable technology to meet the goals of the Paris Agreement,in which Kazakhstan is expected to reduce greenhouse gas emissions by 25%compared with the 1990 level.Unmineable coal seams are an attractive option among all geostorage solutions,as CO_(2)sequestration in coal comes with an income stream via enhanced coalbed methane(ECBM)recovery.This paper identifies four carboniferous coal formations,namely Karagandy,Teniz-Korzhinkol,Ekibustuz,and Chu coal basins of Kazakhstan,as CO_(2)geostorage solutions for their unmineable coal seams.The ideal depth of CO_(2)storage is identified as 800 m to ensure the supercritical state of CO_(2).However,the Ekibustuz coal basin fails to meet the required depth of 800 m in its unmineable coal seams.The conventional formula for calculating CO_(2)storage in coal basins has been modified,and a new formula has been proposed for assessing the CO_(2)storage potential in a coal seam.The CO_(2)storage capacities of unmineable coal seam of these coal basins are 24.60 Bt,0.61 Bt,14.02 Bt,and 5.42 Bt,respectively.The Langmuir volume of the coal fields was calculated using the proximate analysis of coalfields and found to vary between 36.42 and 98.90 m3/ton.This paper is the first to outline CO_(2)storage potential in Kazakhstani coal basins,albeit with limited data,along with a detailed geological and paleographic review of the carboniferous coalfields of Kazakhstan.A short overview of the CO_(2)-ECBM process was also included in the paper.Instead of any experimental work for CO_(2)storage,this paper attempts to present the CO_(2)storage capacity of carboniferous coal formation using the modified version of previously determined formulas for CO_(2)storage.
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.
文摘The work concentrates on extraction of precious metals (Au, Ag, Pd, Pt) and As, Sb, Cu, Pb, Zn, and Fe which are bound to sulfide-ore minerals in sedimentary rocks, using a two-step sequential extraction experiment with two chemical reagents (hydrogen peroxide and aqua regia) on three rock specimens from the black shale formation in Bakyrchik gold-sulfide deposit in North-East Kazakhstan. The experiment allows to determine the speciation of hardly accessible precious metals and to identify the most productive ore-forming stage from the three identified ones. Analytical methods are used for determining polysulfide mineral textures (optical microscopy), mineralogical (XRPD) and chemical compositions (XRF), and for measuring extracted metals concentrations (ICP-OES) in experimental procedures. The analytical results show that the first stage is more productive in gold (total extraction 2.8 ppm) than others and the second stage is more productive in Ag (total 1.6 ppm) and Pd (total 0.01 ppm), while the last stage is more productive in Pt (0.019 ppm) in the deposit.
