Blending of potentially acid generating (PAG) waste rock with non-PAG waste rock to create a rock mixture which performs as non-PAG is a possible approach to permanent prevention of acid rock drainage (ARD) for PAG waste rock. In 2012, a field weathering study using 300 kg samples was implemented at Teck Coal's Quintette Project located in northeastern British Columbia, Canada to test the prevention of acid generation in the PAG waste rock by dissolved carbonate leached from overlying non-PAG waste rock and direct neutralization of acidic water from PAG waste rock by contact with non-PAG waste rock. After eight years of monitoring the experiments, the layered non-PAG on PAG barrels provided proof-of-concept that as the thickness of the PAG layer increases relative to the thickness of the non-PAG layers, acidic waters are more likely to be produced. The PAG on non-PAG layering has resulted in non-acidic water and no indications of metal leaching despite accelerated oxidation in the PAG layer shown by sulfate loadings. The study has demonstrated that the scale of heterogeneity of PAG and non-PAG materials is a critical consideration for providing certainty that rock blends designed to be non-PAG will perform as non-PAG in perpetuity. This is contrary to the standard paradigm in which an excess of acid-consuming minerals is often considered sufficient alone to ensure ARD is not produced.
{"title":"Small-scale field evaluation of geochemical blending of waste rock to mitigate acid rock drainage potential","authors":"S. Day","doi":"10.1144/geochem2021-066","DOIUrl":"https://doi.org/10.1144/geochem2021-066","url":null,"abstract":"Blending of potentially acid generating (PAG) waste rock with non-PAG waste rock to create a rock mixture which performs as non-PAG is a possible approach to permanent prevention of acid rock drainage (ARD) for PAG waste rock. In 2012, a field weathering study using 300 kg samples was implemented at Teck Coal's Quintette Project located in northeastern British Columbia, Canada to test the prevention of acid generation in the PAG waste rock by dissolved carbonate leached from overlying non-PAG waste rock and direct neutralization of acidic water from PAG waste rock by contact with non-PAG waste rock. After eight years of monitoring the experiments, the layered non-PAG on PAG barrels provided proof-of-concept that as the thickness of the PAG layer increases relative to the thickness of the non-PAG layers, acidic waters are more likely to be produced. The PAG on non-PAG layering has resulted in non-acidic water and no indications of metal leaching despite accelerated oxidation in the PAG layer shown by sulfate loadings. The study has demonstrated that the scale of heterogeneity of PAG and non-PAG materials is a critical consideration for providing certainty that rock blends designed to be non-PAG will perform as non-PAG in perpetuity. This is contrary to the standard paradigm in which an excess of acid-consuming minerals is often considered sufficient alone to ensure ARD is not produced.","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":"22 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2021-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42605181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Successful gold exploration projects depend on a piece of clear information on the association between gold, trace elements and mineralization controlling factors. The use of soil geochemistry has been an important tool in pinpointing exploration targets during the early stage of exploration. This study aimed to establish the gold distribution, the elemental association between gold and its pathfinder elements such as Cu, Zn, Ag, Ni, Co, Mn, Fe, Cd, V, Cr, Ti, Sc, In and Se, and identify lithologies contributing to the overlying residual soils. From cluster analysis, a high similarity level of 53.93% has been shown with Ag, Cd and Se at a distance level of 0.92. Au and Se have a similarity level of 65.87% and a distance level of 0.68; hence, is proposed to be the most promising pathfinder element. Principal component analysis (PCA), factor analysis (FA) and the Pearson's correlation matrix of transformed data of V, Cu, Ni, Fe, Mn, Cr and Co, and a stronger correlation between Pb and U, Th, Na, K, Sn, Y, Ta and Be shows that source gold mineralization might be associated with both hornblende gneisses interlayered with quartzite, tonalite and tonalitic orthogneiss. From the contour map and gridded map of Au and its pathfinder elements, it has been noted that their anomalies and generated targets are localized in the northern part of the area. The targets trend ESE–WNW, nearly parallel to the shear zones as a controlling factor of Au mineralization emplacement. Supplementary material: Concentration data for each of the 44 elements analysed are available at https://doi.org/10.6084/m9.figshare.c.5721965
{"title":"Geochemical evaluation of the in situ regolith at Madengi Hill, Dodoma, Tanzania: implications for bedrock mapping and delineating gold mineralization targets","authors":"Godson Godfray","doi":"10.1144/geochem2021-074","DOIUrl":"https://doi.org/10.1144/geochem2021-074","url":null,"abstract":"Successful gold exploration projects depend on a piece of clear information on the association between gold, trace elements and mineralization controlling factors. The use of soil geochemistry has been an important tool in pinpointing exploration targets during the early stage of exploration. This study aimed to establish the gold distribution, the elemental association between gold and its pathfinder elements such as Cu, Zn, Ag, Ni, Co, Mn, Fe, Cd, V, Cr, Ti, Sc, In and Se, and identify lithologies contributing to the overlying residual soils. From cluster analysis, a high similarity level of 53.93% has been shown with Ag, Cd and Se at a distance level of 0.92. Au and Se have a similarity level of 65.87% and a distance level of 0.68; hence, is proposed to be the most promising pathfinder element. Principal component analysis (PCA), factor analysis (FA) and the Pearson's correlation matrix of transformed data of V, Cu, Ni, Fe, Mn, Cr and Co, and a stronger correlation between Pb and U, Th, Na, K, Sn, Y, Ta and Be shows that source gold mineralization might be associated with both hornblende gneisses interlayered with quartzite, tonalite and tonalitic orthogneiss. From the contour map and gridded map of Au and its pathfinder elements, it has been noted that their anomalies and generated targets are localized in the northern part of the area. The targets trend ESE–WNW, nearly parallel to the shear zones as a controlling factor of Au mineralization emplacement. Supplementary material: Concentration data for each of the 44 elements analysed are available at https://doi.org/10.6084/m9.figshare.c.5721965","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2021-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43479111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Hashmi, M. Leybourne, S. Hamilton, D. Layton-Matthews, M. McClenaghan
A geochemical study over the southwestern part of the South Range of the Sudbury Igneous Complex was completed to assess the suitability of surficial media (humus, B-horizon soil and C-horizon soil) for delineating geochemical anomalies associated with Ni–Cu–PGE (platinum group element) mineralization. Another objective was to test whether Na pyrophosphate can eliminate the effects of anthropogenic contamination in humus. Results of this study suggest that the natural geochemical signature of humus is strongly overprinted by anthropogenic contamination. Despite no indication of underlying or nearby mineralization, metal concentrations in humus samples by aqua regia collected downwind from smelting operations are higher compared to background, including up to 13 times higher for Pt, 12 times higher for Cu and nine times higher for Ni. The high anthropogenic background masks the geogenic signal such that it is only apparent in humus samples collected in the vicinity of known Ni–Cu–PGE deposits. Results of this study also demonstrate that anthropogenically derived atmospheric fallout also influences the upper B-horizon soil; however, lower B-horizon soil (at >20 cm depth) and C-horizon soil (both developed in till) are not affected. Glacial dispersal from Ni–Cu–PGE mineralization is apparent in C-horizon till samples analysed in this study. Compared to the background concentrations, the unaffected C-horizon till samples collected immediately down-ice of the low-sulfide, high precious metal Vermilion Cu–Ni–PGE deposit are enriched over 20 times in Pt (203 ppb), Au (81 ppm) and Cu (963 ppm), and over 30 times in Ni (1283 ppm). Supplementary material: supplementary tables and figures are available at https://doi.org/10.6084/m9.figshare.c.5691080
{"title":"Suitability of surficial media for Ni–Cu–PGE exploration in an established mining camp: a case study from the South Range of the Sudbury Igneous Complex, Canada","authors":"S. Hashmi, M. Leybourne, S. Hamilton, D. Layton-Matthews, M. McClenaghan","doi":"10.1144/geochem2021-051","DOIUrl":"https://doi.org/10.1144/geochem2021-051","url":null,"abstract":"A geochemical study over the southwestern part of the South Range of the Sudbury Igneous Complex was completed to assess the suitability of surficial media (humus, B-horizon soil and C-horizon soil) for delineating geochemical anomalies associated with Ni–Cu–PGE (platinum group element) mineralization. Another objective was to test whether Na pyrophosphate can eliminate the effects of anthropogenic contamination in humus. Results of this study suggest that the natural geochemical signature of humus is strongly overprinted by anthropogenic contamination. Despite no indication of underlying or nearby mineralization, metal concentrations in humus samples by aqua regia collected downwind from smelting operations are higher compared to background, including up to 13 times higher for Pt, 12 times higher for Cu and nine times higher for Ni. The high anthropogenic background masks the geogenic signal such that it is only apparent in humus samples collected in the vicinity of known Ni–Cu–PGE deposits. Results of this study also demonstrate that anthropogenically derived atmospheric fallout also influences the upper B-horizon soil; however, lower B-horizon soil (at >20 cm depth) and C-horizon soil (both developed in till) are not affected. Glacial dispersal from Ni–Cu–PGE mineralization is apparent in C-horizon till samples analysed in this study. Compared to the background concentrations, the unaffected C-horizon till samples collected immediately down-ice of the low-sulfide, high precious metal Vermilion Cu–Ni–PGE deposit are enriched over 20 times in Pt (203 ppb), Au (81 ppm) and Cu (963 ppm), and over 30 times in Ni (1283 ppm). Supplementary material: supplementary tables and figures are available at https://doi.org/10.6084/m9.figshare.c.5691080","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2021-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44365016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Knaack, Gillian Ivey, Caitlyn MacPhee, Jordan Peterzon, Liam Price, M. Williams, M. Leybourne
In hydrogeochemical studies, samples are commonly filtered to limit the fraction of analyte that is adsorbed or structurally bound to suspended particles, ensuring that only the dissolved fraction is analysed, and thereby reducing analytical bias during measurement. The standard filter size that has been adopted is 0.45 μm; however, ultrafiltration can be used to remove colloidal particles two orders of magnitude smaller. In the following, we investigate the effect that standard filtration (0.45 μm) and ultrafiltration (0.004 μm) have on the hydrogeochemistry of groundwaters from a volcanogenic massive sulfide (VMS) deposit at the Bathurst Mining Camp, New Brunswick, Canada. Groundwater samples were collected from six monitoring wells at the Nigadoo Mine tailings facility, and major and trace geochemistry were determined using a combination of inductively coupled plasma optical emission spectrometry, inductively coupled plasma mass spectrometry and ion chromatography. Waters at the Nigadoo deposit are generally enriched in Ca and SO4, relative to other major cations and anions. Some element contents – including those associated with VMS deposits – differ depending on the filtration technique used (e.g. As, Fe, Pb, rare earth elements and yttrium (REY)), some are equally affected by both techniques (e.g. Cu, Ni, Zn), and some are unaffected by filtration (e.g. Ba, Ca, Mn, Cl−). Shale-normalized REY anomalies (CeSN/CeSN*, EuSN/EuSN* and YSN/HoSN) and overall patterns can differ greatly (e.g. changing the sign of the anomaly) depending on the filtration technique used. We observe previously undocumented and, at this time, unexplainable fractionation of Ho and Yb (non-redox sensitive REY, unaffected by the tetrad effect) in unfiltered waters from the Nigadoo deposit. Differences in groundwater geochemistry induced by filtration technique can result in false positive and negative anomalies during environmental and exploration projects and must therefore be carefully considered. At the Nigadoo site, oxidation of sulfide minerals can occur, resulting in the formation of relatively unstable oxide minerals. Away from the tailings, where carbonate minerals are scarce and can no longer act as a pH buffer, the unstable oxide minerals break down and release metals and metalloids into the surrounding environment. The filtration methods used in this study can provide insight into where the specific metals and metalloids are hosted and how they are likely to behave under different redox conditions. Because VMS deposit pathfinder elements are enriched in unfiltered water, and differ by degree of filtration, geochemical analysis of the filtride material may also make an effective exploration tool. Thematic collection: This article is part of the Hydrochemistry related to exploration and environmental issues collection available at: https://www.lyellcollection.org/cc/hydrochemistry-related-to-exploration-and-environmental-issues
{"title":"The effect of filtration size on the geochemistry of groundwater samples from a massive sulfide deposit at the Bathurst Mining Camp, New Brunswick, Canada","authors":"D. Knaack, Gillian Ivey, Caitlyn MacPhee, Jordan Peterzon, Liam Price, M. Williams, M. Leybourne","doi":"10.1144/geochem2021-057","DOIUrl":"https://doi.org/10.1144/geochem2021-057","url":null,"abstract":"In hydrogeochemical studies, samples are commonly filtered to limit the fraction of analyte that is adsorbed or structurally bound to suspended particles, ensuring that only the dissolved fraction is analysed, and thereby reducing analytical bias during measurement. The standard filter size that has been adopted is 0.45 μm; however, ultrafiltration can be used to remove colloidal particles two orders of magnitude smaller. In the following, we investigate the effect that standard filtration (0.45 μm) and ultrafiltration (0.004 μm) have on the hydrogeochemistry of groundwaters from a volcanogenic massive sulfide (VMS) deposit at the Bathurst Mining Camp, New Brunswick, Canada. Groundwater samples were collected from six monitoring wells at the Nigadoo Mine tailings facility, and major and trace geochemistry were determined using a combination of inductively coupled plasma optical emission spectrometry, inductively coupled plasma mass spectrometry and ion chromatography. Waters at the Nigadoo deposit are generally enriched in Ca and SO4, relative to other major cations and anions. Some element contents – including those associated with VMS deposits – differ depending on the filtration technique used (e.g. As, Fe, Pb, rare earth elements and yttrium (REY)), some are equally affected by both techniques (e.g. Cu, Ni, Zn), and some are unaffected by filtration (e.g. Ba, Ca, Mn, Cl−). Shale-normalized REY anomalies (CeSN/CeSN*, EuSN/EuSN* and YSN/HoSN) and overall patterns can differ greatly (e.g. changing the sign of the anomaly) depending on the filtration technique used. We observe previously undocumented and, at this time, unexplainable fractionation of Ho and Yb (non-redox sensitive REY, unaffected by the tetrad effect) in unfiltered waters from the Nigadoo deposit. Differences in groundwater geochemistry induced by filtration technique can result in false positive and negative anomalies during environmental and exploration projects and must therefore be carefully considered. At the Nigadoo site, oxidation of sulfide minerals can occur, resulting in the formation of relatively unstable oxide minerals. Away from the tailings, where carbonate minerals are scarce and can no longer act as a pH buffer, the unstable oxide minerals break down and release metals and metalloids into the surrounding environment. The filtration methods used in this study can provide insight into where the specific metals and metalloids are hosted and how they are likely to behave under different redox conditions. Because VMS deposit pathfinder elements are enriched in unfiltered water, and differ by degree of filtration, geochemical analysis of the filtride material may also make an effective exploration tool. Thematic collection: This article is part of the Hydrochemistry related to exploration and environmental issues collection available at: https://www.lyellcollection.org/cc/hydrochemistry-related-to-exploration-and-environmental-issues","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48486026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Gammons, M. F. Doolittle, K. Eastman, S. Poulson
This paper investigates natural acid rock drainage in two streams draining either side of Mt Evans, Montana. Bedrock consists of pyrrhotite-bearing schist intruded by granitic dykes and plutons of Late Cretaceous to Tertiary age. The headwaters of both streams are moderately acidic (pH < 5.0) and carry elevated loads of dissolved sulfate, aluminum and other trace metals (Cd, Co, Cu, Mn, Zn) as well as rare earth elements (REEs). Copious aluminum precipitates inferred to be hydrobasaluminite coat boulders of both streams as pH rises > 5, with adsorption of copper and REEs. Concentrations and loads of dissolved sulfate and trace elements are anomalously high in a small tributary that is sourced by meltwater from a rock glacier. The S-isotope composition of dissolved sulfate in both watersheds is similar to that of pyrrhotite in the meta-sediments, but not molybdenite in late porphyry dykes. Calculations of sulfate flux (i.e. sulfate load divided by surface area) indicate a relatively fast rate of sulfide oxidation in the study area, possibly due to exposure of fresh bedrock in the steep and recently glaciated field area. Overall, the geochemistry of the site suggests the possible presence of a metamorphosed sedimentary–exhalative deposit, a possibility that is unlikely to be tested by drilling given the proximity of the site to a federal wilderness area. Supplementary material: All analytical data related to this project, additional maps and photographs, and selected results from geochemical modelling are available at https://doi.org/10.6084/m9.figshare.c.5649850 Thematic collection: This article is part of the Hydrochemistry related to exploration and environmental issues collection available at: https://www.lyellcollection.org/cc/hydrochemistry-related-to-exploration-and-environmental-issues
{"title":"Geochemistry of natural acid rock drainage in the Mt Evans area, Anaconda–Pintler Range, Montana, USA","authors":"C. Gammons, M. F. Doolittle, K. Eastman, S. Poulson","doi":"10.1144/geochem2021-068","DOIUrl":"https://doi.org/10.1144/geochem2021-068","url":null,"abstract":"This paper investigates natural acid rock drainage in two streams draining either side of Mt Evans, Montana. Bedrock consists of pyrrhotite-bearing schist intruded by granitic dykes and plutons of Late Cretaceous to Tertiary age. The headwaters of both streams are moderately acidic (pH < 5.0) and carry elevated loads of dissolved sulfate, aluminum and other trace metals (Cd, Co, Cu, Mn, Zn) as well as rare earth elements (REEs). Copious aluminum precipitates inferred to be hydrobasaluminite coat boulders of both streams as pH rises > 5, with adsorption of copper and REEs. Concentrations and loads of dissolved sulfate and trace elements are anomalously high in a small tributary that is sourced by meltwater from a rock glacier. The S-isotope composition of dissolved sulfate in both watersheds is similar to that of pyrrhotite in the meta-sediments, but not molybdenite in late porphyry dykes. Calculations of sulfate flux (i.e. sulfate load divided by surface area) indicate a relatively fast rate of sulfide oxidation in the study area, possibly due to exposure of fresh bedrock in the steep and recently glaciated field area. Overall, the geochemistry of the site suggests the possible presence of a metamorphosed sedimentary–exhalative deposit, a possibility that is unlikely to be tested by drilling given the proximity of the site to a federal wilderness area. Supplementary material: All analytical data related to this project, additional maps and photographs, and selected results from geochemical modelling are available at https://doi.org/10.6084/m9.figshare.c.5649850 Thematic collection: This article is part of the Hydrochemistry related to exploration and environmental issues collection available at: https://www.lyellcollection.org/cc/hydrochemistry-related-to-exploration-and-environmental-issues","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45071394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Haiyan Liu, Weimin Zhang, J. Mo, Zhen Wang, Jiahong Chen, Junhua Chen, Z. Zhuo
Uranium (U) ion contamination in aquatic systems has received considerable attention worldwide. In this paper, an adsorption material was synthesized with a Fe/Ca-based phosphate (CFB-PM) by a sol–gel method. The effect of pH, reaction time and initial concentration of U ions on its capacity to remove U ions from aqueous solution was investigated via static batch experiments. Comparative studies of U ion removal by CFB-PM with four sorbents, namely: nano zero-valent iron (nZVI), hydroxyapatite (HAP), hydroxyapatite-loaded nano zero-valent iron (HAP@nZVI) and high basicity steel slag-loaded hydroxyapatite (HBSS@HAP), were performed. Results showed that U ion adsorption capacity of CFB-PM was better than that of all four. The adsorption capacity showed a decreasing order as: CFB-PM (643.34 mg g–1) > HAP (549.86 mg g–1) > HBSS@HAP (321.82 mg g–1) > HAP@nZVI (153.62 mg g–1) > nZVI (102.65 mg g–1). Scanning electron microscopy energy-dispersive spectrometry examination suggested that the adsorbed U ions were mainly in the form of spheres, sheets or petals on the surfaces of CFB-PM. X-ray diffraction revealed several U-bearing mineral phases (i.e. Ca(UO2)2(PO4)2·3H2O, HPUO6·4H2O and (UO2)3PO4·4H2O). The U ion adsorption behaviours were further explored by Fourier transform IR spectroscopy. The U ion adsorption process of CFB-PM could be well described by a quasi-second-order adsorption kinetics model and the Langmuir adsorption isotherm model. The separation coefficient (RL) was close to zero, indicating that U ion adsorption was dominated by single-layer chemisorption. The findings reported in this study have implications for applying the synthesized material for remediation of U ion-contaminated groundwater.
{"title":"Synthesis of a Fe/Ca-based phosphate material and its application for adsorption of uranium ions from aqueous solution","authors":"Haiyan Liu, Weimin Zhang, J. Mo, Zhen Wang, Jiahong Chen, Junhua Chen, Z. Zhuo","doi":"10.1144/geochem2021-052","DOIUrl":"https://doi.org/10.1144/geochem2021-052","url":null,"abstract":"Uranium (U) ion contamination in aquatic systems has received considerable attention worldwide. In this paper, an adsorption material was synthesized with a Fe/Ca-based phosphate (CFB-PM) by a sol–gel method. The effect of pH, reaction time and initial concentration of U ions on its capacity to remove U ions from aqueous solution was investigated via static batch experiments. Comparative studies of U ion removal by CFB-PM with four sorbents, namely: nano zero-valent iron (nZVI), hydroxyapatite (HAP), hydroxyapatite-loaded nano zero-valent iron (HAP@nZVI) and high basicity steel slag-loaded hydroxyapatite (HBSS@HAP), were performed. Results showed that U ion adsorption capacity of CFB-PM was better than that of all four. The adsorption capacity showed a decreasing order as: CFB-PM (643.34 mg g–1) > HAP (549.86 mg g–1) > HBSS@HAP (321.82 mg g–1) > HAP@nZVI (153.62 mg g–1) > nZVI (102.65 mg g–1). Scanning electron microscopy energy-dispersive spectrometry examination suggested that the adsorbed U ions were mainly in the form of spheres, sheets or petals on the surfaces of CFB-PM. X-ray diffraction revealed several U-bearing mineral phases (i.e. Ca(UO2)2(PO4)2·3H2O, HPUO6·4H2O and (UO2)3PO4·4H2O). The U ion adsorption behaviours were further explored by Fourier transform IR spectroscopy. The U ion adsorption process of CFB-PM could be well described by a quasi-second-order adsorption kinetics model and the Langmuir adsorption isotherm model. The separation coefficient (RL) was close to zero, indicating that U ion adsorption was dominated by single-layer chemisorption. The findings reported in this study have implications for applying the synthesized material for remediation of U ion-contaminated groundwater.","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2021-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48568568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mobile radiogenic lead isotopes (206Pb, 207Pb, 208Pb and 210Pb) represent products of radioactive decay of their parental uranium and thorium isotopes (238U, 235U, 232Th), and are considered potential geochemical pathfinders of buried sandstone-type uranium deposits. Soil samples collected along a geochemical traverse intersecting buried uranium roll front mineralization at the REB deposit in the Great Divide Basin, Wyoming, USA were studied. Mineralization of this deposit is hosted in weakly lithified arkosic sands, at a depth of 120–200 m, without a strong surficial expression of its presence at depth, which makes discovery of this deposit type difficult, slow and expensive. All soil samples have been analysed for ratios of the mobile long-lived Pb isotopes and their parental U and Th isotopes, determined from partial leach products obtained using a weak acid leaching technique. The samples were also analysed for trace elements, assayed both in the partial leach products and using conventional whole-soil sample assays. Ratios of the mobile radiogenic Pb isotopes to their parental U and Th isotopes (206Pb/238U, 207Pb/235U and 208Pb/232Th) determined in the partial leach products exhibit anomalous contents in the soil samples collected above the uranium rolls. The anomalous values are several times greater than background values, to lateral distances of 350–400 m outside of the roll fronts. Notably, conventional whole-soil assays have failed to detect the anomalies that were detected using mobile Pb isotopes. Supplementary material: Minor and trace elements assays of the geochemical samples are available at https://doi.org/10.6084/m9.figshare.c.5610980
{"title":"Geochemical exploration for buried sandstone-hosted uranium mineralization using mobile U and Pb isotopes: case study of the REB deposit, Great Divide Basin, Wyoming","authors":"M. Abzalov","doi":"10.1144/geochem2021-043","DOIUrl":"https://doi.org/10.1144/geochem2021-043","url":null,"abstract":"Mobile radiogenic lead isotopes (206Pb, 207Pb, 208Pb and 210Pb) represent products of radioactive decay of their parental uranium and thorium isotopes (238U, 235U, 232Th), and are considered potential geochemical pathfinders of buried sandstone-type uranium deposits. Soil samples collected along a geochemical traverse intersecting buried uranium roll front mineralization at the REB deposit in the Great Divide Basin, Wyoming, USA were studied. Mineralization of this deposit is hosted in weakly lithified arkosic sands, at a depth of 120–200 m, without a strong surficial expression of its presence at depth, which makes discovery of this deposit type difficult, slow and expensive. All soil samples have been analysed for ratios of the mobile long-lived Pb isotopes and their parental U and Th isotopes, determined from partial leach products obtained using a weak acid leaching technique. The samples were also analysed for trace elements, assayed both in the partial leach products and using conventional whole-soil sample assays. Ratios of the mobile radiogenic Pb isotopes to their parental U and Th isotopes (206Pb/238U, 207Pb/235U and 208Pb/232Th) determined in the partial leach products exhibit anomalous contents in the soil samples collected above the uranium rolls. The anomalous values are several times greater than background values, to lateral distances of 350–400 m outside of the roll fronts. Notably, conventional whole-soil assays have failed to detect the anomalies that were detected using mobile Pb isotopes. Supplementary material: Minor and trace elements assays of the geochemical samples are available at https://doi.org/10.6084/m9.figshare.c.5610980","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2021-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44282541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bin Liang, G. Han, Jie Zeng, Rui Qu, Man Liu, Jinke Liu
Rare-earth elements (REEs) in soils are influenced by pedogenic processes and anthropogenic activities. To interpret the fractionation and migration of REEs during weathering in (sub-)tropical regions, the distribution, fractionation patterns and environmental effects of REEs in laterites were investigated in this study. Soil samples from two laterite profiles (labelled S1 and S2) were collected and the concentrations of REEs were measured with an inductively coupled plasma mass spectrometer. The results suggest that the ΣREEs of S2 (119 ± 10 mg kg–1 to 209 ± 10 mg kg–1) have a higher concentration and a wider variation than those of S1 (114 ± 5 mg kg–1 to 154 ± 8 mg kg–1). The REEs in both laterite profiles are enriched in the order HREEs > LREEs > MREEs. The distribution patterns of laterite profiles show evidence of inheritance from parent granites. The laterites preferentially incorporated HREEs, and secondary Fe2O3 and clay minerals were likely to affect the fractionation of REEs in laterites. The enrichment factor of REEs varied from 11.1 to 18.9 for S1 and 10.0 to 27.6 for S1, indicating potential pollution by REEs. The accumulation of REEs in laterites by mining activity should be a concern of government environmental agencies. Supplementary material: Table S1, Reference values of REEs and Fe2O3 in standard materials (GSS-18 and GSS-20); Table S2, Measurement parameters of ICP-MS; Table S3, Concentrations of REEs and Fe2O3 in laterite profiles from Yunnan province, SW China; Table S4, The enrichment factor for the laterite profiles from Yunnan province, SW China are available at https://doi.org/10.6084/m9.figshare.c.5609234
{"title":"Geochemistry and environmental effects of rare-earth elements in laterites from Yunnan province, SW China","authors":"Bin Liang, G. Han, Jie Zeng, Rui Qu, Man Liu, Jinke Liu","doi":"10.1144/geochem2021-039","DOIUrl":"https://doi.org/10.1144/geochem2021-039","url":null,"abstract":"Rare-earth elements (REEs) in soils are influenced by pedogenic processes and anthropogenic activities. To interpret the fractionation and migration of REEs during weathering in (sub-)tropical regions, the distribution, fractionation patterns and environmental effects of REEs in laterites were investigated in this study. Soil samples from two laterite profiles (labelled S1 and S2) were collected and the concentrations of REEs were measured with an inductively coupled plasma mass spectrometer. The results suggest that the ΣREEs of S2 (119 ± 10 mg kg–1 to 209 ± 10 mg kg–1) have a higher concentration and a wider variation than those of S1 (114 ± 5 mg kg–1 to 154 ± 8 mg kg–1). The REEs in both laterite profiles are enriched in the order HREEs > LREEs > MREEs. The distribution patterns of laterite profiles show evidence of inheritance from parent granites. The laterites preferentially incorporated HREEs, and secondary Fe2O3 and clay minerals were likely to affect the fractionation of REEs in laterites. The enrichment factor of REEs varied from 11.1 to 18.9 for S1 and 10.0 to 27.6 for S1, indicating potential pollution by REEs. The accumulation of REEs in laterites by mining activity should be a concern of government environmental agencies. Supplementary material: Table S1, Reference values of REEs and Fe2O3 in standard materials (GSS-18 and GSS-20); Table S2, Measurement parameters of ICP-MS; Table S3, Concentrations of REEs and Fe2O3 in laterite profiles from Yunnan province, SW China; Table S4, The enrichment factor for the laterite profiles from Yunnan province, SW China are available at https://doi.org/10.6084/m9.figshare.c.5609234","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2021-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48348224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. El Alaoui, A. Dekayir, Mohammed Rouai, El Mehdi Benyassine
In the Zeida abandoned mine, pit lake waters exhibit alkaline pH and high conductivity. The concentrations of the total dissolved lead and zinc are very low due to their adsorption on clay minerals and iron oxyhydroxides. Conversely, arsenic concentrations in two lakes (ZL1 and ZA) exceed WHO water quality guidelines. The As content is relatively high in ZL1 and exists mainly as As(V). In ZA, As(III) occurs in low concentration compared to the total dissolved arsenic, while dimethylarsenic acid (H2AsO2(CH3)2, DMA) prevails. This means that arsenic was methylated by organic matter produced by micro-organisms such as chlorella. The sequential extraction of floor sediments in the two lakes shows that the bioavailable arsenic contents change between them. In ZA, the sediments show high concentrations of lead and arsenic compared to the ZL1 sediment since it is surrounded by mining waste tailings, which are rich in these elements. An arsenic leaching test of ZA sediment shows that bioavailable arsenic is distributed in equal proportion between clay/carbonates, sulfide-organic matter and iron oxide phases, while in ZL1, most of the arsenic is linked to hydrous iron oxides. Supplementary material: Information on quality control/quality insurance for the used analytical techniques, and additional figures 9–13 are available at https://doi.org/10.6084/m9.figshare.c.5545316 Thematic collection: This article is part of the Hydrochemistry related to exploration and environmental issues collection available at: https://www.lyellcollection.org/cc/hydrochemistry-related-to-exploration-and-environmental-issues
{"title":"Lead, zinc and arsenic contamination of pit lake waters in the Zeida abandoned mine (High Moulouya, Morocco)","authors":"L. El Alaoui, A. Dekayir, Mohammed Rouai, El Mehdi Benyassine","doi":"10.1144/geochem2021-009","DOIUrl":"https://doi.org/10.1144/geochem2021-009","url":null,"abstract":"In the Zeida abandoned mine, pit lake waters exhibit alkaline pH and high conductivity. The concentrations of the total dissolved lead and zinc are very low due to their adsorption on clay minerals and iron oxyhydroxides. Conversely, arsenic concentrations in two lakes (ZL1 and ZA) exceed WHO water quality guidelines. The As content is relatively high in ZL1 and exists mainly as As(V). In ZA, As(III) occurs in low concentration compared to the total dissolved arsenic, while dimethylarsenic acid (H2AsO2(CH3)2, DMA) prevails. This means that arsenic was methylated by organic matter produced by micro-organisms such as chlorella. The sequential extraction of floor sediments in the two lakes shows that the bioavailable arsenic contents change between them. In ZA, the sediments show high concentrations of lead and arsenic compared to the ZL1 sediment since it is surrounded by mining waste tailings, which are rich in these elements. An arsenic leaching test of ZA sediment shows that bioavailable arsenic is distributed in equal proportion between clay/carbonates, sulfide-organic matter and iron oxide phases, while in ZL1, most of the arsenic is linked to hydrous iron oxides. Supplementary material: Information on quality control/quality insurance for the used analytical techniques, and additional figures 9–13 are available at https://doi.org/10.6084/m9.figshare.c.5545316 Thematic collection: This article is part of the Hydrochemistry related to exploration and environmental issues collection available at: https://www.lyellcollection.org/cc/hydrochemistry-related-to-exploration-and-environmental-issues","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2021-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45608574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Rabiei, G. Chi, E. Potter, V. Tschirhart, C. MacKay, S. Frostad, R. McElroy, R. Ashley, B. McEwan
The Patterson Lake corridor (PLC) in the southwestern margin of the Athabasca Basin hosts several high-grade uranium deposits. These deposits are located in the basement up to 900 m below the unconformity surface, raising questions about their affiliation with typical unconformity-related uranium (URU) deposits elsewhere in the basin. Based on cross-cutting relationships four pre- and three syn- to post-mineralization quartz generations were identified. Fluid inclusion analyses indicate that pre-mineralization fluids have salinities ranging from 0.2 to 27.2 wt% NaCl equiv. (avg. 9.0 wt%), whereas syn-mineralization fluids have salinities ranging from 8.8 to 33.8 wt% NaCl + CaCl2 (avg. 25.4 wt%), with NaCl- and CaCl2-rich varieties. The homogenization temperatures (Th) of fluid inclusions from pre-mineralization quartz range from 80 to 244°C (avg. 147°C), and from syn-mineralization quartz range from 64 to 248°C (avg. 128°C). Fluid boiling is indicated by the co-development of liquid-dominated and vapour-dominated fluid inclusions within individual fluid inclusion assemblages from the syn-mineralization quartz and is related to episodic fluid pressure drops caused by reactivation of basement faults. Our results indicate that composition and P–T conditions of the ore fluids in the PLC are comparable to those of typical URU deposits in the Athabasca Basin, indicating that the uranium deposits in the PLC formed under similar hydrothermal conditions. Episodic reactivation of basement faults was an important driving force to draw uraniferous fluids from the basin and reducing fluids from the basement to the mineralization sites, forming deep basement-hosted deposits. Supplementary material: Table 1, microthermometric results of type-2 and -5 fluid inclusion assembladges and isolated inclusions from the Patterson Lake corridor, and table 2, microthermometric results of type-6 fluid inclusions from the Patterson Lake corridor are available at https://doi.org/10.6084/m9.figshare.c.5510179 Thematic collection: This article is part of the Uranium Fluid Pathways collection available at: https://www.lyellcollection.org/cc/uranium-fluid-pathways
{"title":"Fluid evolution along the Patterson Lake corridor in the southwestern Athabasca Basin: constraints from fluid inclusions and implications for unconformity-related uranium mineralization","authors":"M. Rabiei, G. Chi, E. Potter, V. Tschirhart, C. MacKay, S. Frostad, R. McElroy, R. Ashley, B. McEwan","doi":"10.1144/geochem2020-029","DOIUrl":"https://doi.org/10.1144/geochem2020-029","url":null,"abstract":"The Patterson Lake corridor (PLC) in the southwestern margin of the Athabasca Basin hosts several high-grade uranium deposits. These deposits are located in the basement up to 900 m below the unconformity surface, raising questions about their affiliation with typical unconformity-related uranium (URU) deposits elsewhere in the basin. Based on cross-cutting relationships four pre- and three syn- to post-mineralization quartz generations were identified. Fluid inclusion analyses indicate that pre-mineralization fluids have salinities ranging from 0.2 to 27.2 wt% NaCl equiv. (avg. 9.0 wt%), whereas syn-mineralization fluids have salinities ranging from 8.8 to 33.8 wt% NaCl + CaCl2 (avg. 25.4 wt%), with NaCl- and CaCl2-rich varieties. The homogenization temperatures (Th) of fluid inclusions from pre-mineralization quartz range from 80 to 244°C (avg. 147°C), and from syn-mineralization quartz range from 64 to 248°C (avg. 128°C). Fluid boiling is indicated by the co-development of liquid-dominated and vapour-dominated fluid inclusions within individual fluid inclusion assemblages from the syn-mineralization quartz and is related to episodic fluid pressure drops caused by reactivation of basement faults. Our results indicate that composition and P–T conditions of the ore fluids in the PLC are comparable to those of typical URU deposits in the Athabasca Basin, indicating that the uranium deposits in the PLC formed under similar hydrothermal conditions. Episodic reactivation of basement faults was an important driving force to draw uraniferous fluids from the basin and reducing fluids from the basement to the mineralization sites, forming deep basement-hosted deposits. Supplementary material: Table 1, microthermometric results of type-2 and -5 fluid inclusion assembladges and isolated inclusions from the Patterson Lake corridor, and table 2, microthermometric results of type-6 fluid inclusions from the Patterson Lake corridor are available at https://doi.org/10.6084/m9.figshare.c.5510179 Thematic collection: This article is part of the Uranium Fluid Pathways collection available at: https://www.lyellcollection.org/cc/uranium-fluid-pathways","PeriodicalId":55114,"journal":{"name":"Geochemistry-Exploration Environment Analysis","volume":" ","pages":""},"PeriodicalIF":2.4,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48755690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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