Geochemical modeling for predicting potential solid phases controlling the dissolved molybdenum in coal overburden,Powder River Basin,WY, U.S.A.

Surface coal mining processes may increase the dissolved Mo concentrations in overburden (mine spoils) and in nearby soils. Spoil and soil samples were subjected to solubility studies for determining potential solid phases controlling the dissolved Mo. Additionally, native soil samples were included in the study for comparison. Ion activity products (IAPs) were calculated from the total elemental concentrations of aqueous extracts and compared with solubility products (K_sps) of Mo solid phases. Effects of dissolved organic carbon (DOC) on metal ion complexation were also evaluated. The pH of aqueous extracts ranged from 7.14 to 8.31. DOC in aqueous extracts varied from 17.3 to 58.7 mg/l. Molybdenum concentrations in aqueous extracts ranged between 11.5 and 35.6 μg/l for spoils, 13.5 and 20.0 μg/l for soils near mine site and 14.5 and 29.6 μg/l for native soils. Initially, IAPs suggested varying degrees of supersaturation with respect to wulfenite (PbMoO₄). However, when DOC-Pb²⁺ complexes were considered, the IAPs indicated a close approach to saturation with respect to PbMoO₄. Furthermore, the IAPs suggested a high degree of undersaturation with respect to powellite (CaMoO₄) and ferrimolybdite (FeMoO₄). Results in this study suggest the dissolved Mo concentrations in mine spoils and soils that are near coal mine may be controlled by PbMoO₄ solid phase.     

Accumulation of elements in plants and soils in and around Mangampeta and Vemula barite mining areas, Cuddapah District, Andhra Pradesh, India

Different plant organs and their corresponding substrate samples were collected from Mangampeta and Vemula barite mining areas of Cuddapah District, Andhra Pradesh. The presence of Indigofera cordifolia exclusively developed on mine dumps of the Vemula barite area and its significant absence away from the mining area shows its indicator characteristics for barium from the geobotanical point of view. Multi-element analysis of these samples was carried out and thebiological absorption coefficient (BAC) was calculated. The BAC is the ratio of the concentration of an element in plant ash to that of its substrate. The results show the presence and/or absence of certain elements in plants and soils, which can be explained on the basis of biogeochemical cycling of elements, exclusion mechanisms, and bioavailability. Further, Tridax procumbens (Li), I. cordifolia (Ba), Cassia angustifolia (Sr), and Kirganelia reticulata (Co) are identified as accumulator plants without considering their substrate concentration. Based on BAC, C. angustifolia (Sr) and Tephrosia purpurea (Zn) are determined to be accumulator plants. Such plant species may be useful in mineral exploration, and reclamation and revegetation of adversely affected mining environments.     

云南省武定县土壤重金属地球化学分布特征及其来源浅析

为探明西南地区耕地土壤重金属污染的分布特征及来源,选取云南省武定县优耕区为研究区,在分析1802件表层土壤和4条剖面土壤重金属含量的基础上,运用地累积指数法评估重金属污染风险,利用地统计分析、单因子方差分析、正定矩阵分析探讨重金属的空间分布特征、污染水平及潜在来源。8种重金属与云南省背景值相差较小,其中Cr、Ni平均含量高于云南省背景值,是其背景值的1.75和1.14倍,As、Cu、Hg、Ni、Pb和Zn低于其背景值。8种重金属元素呈现东高西低、南高北低的分布趋势,异常区分布规律明显。地累积指数结果表明,8种重金属中仅Cd存在轻微污染,其余元素均处于无污染水平,与以往认为西南地区是地质高背景区、土壤污染严重有较大出入,需要对西南重金属高背景区的观点进行重新认识和修订。研究区内8种重金属主要有3个污染源:矿业开采源、肥料和交通污染源和成土母质源。其中,As、Cu、Hg主要受迤纳厂铜矿开采的影响; Pb、Cd、Zn受刺竹箐铅锌矿床的开采、交通污染和肥料施用的共同影响; Cr、Ni受成土母质影响较大。     

煤矸石释放重金属环境效应研究--淮南煤矿塌陷区水体试验场实例调查

概要分析了淮南新孜5号井煤矸石所含的重金属元素对塌陷区鱼塘水质的影响,指出除个别水样中Zn、Cu超标外,其他均不超标,该鱼塘水质适宜养鱼要求。矸石样与华北及整个地壳泥岩中元素的丰度比,矸石中Cr、Pb、Zn与泥岩丰度基本持平,而Cd、Cu均超过其他泥岩中丰度值。因此,煤矸石在地面遭受风化,其所含有害物质可能会释放到环境,在煤矸石堆放处适当进行监测还是必要的。     

Copper, nickel and zinc contamination in soils within the precincts of mining and landfilling environments

This study determined copper, nickel and zinc concentrations in soils within the precincts of a copper-nickel mining and urban landfilling environments, and used obtained values to appraise the degree of soil contamination and pollution based on geoaccumulation index, contamination factor and pollution load index. Mean concentrations of copper (252.4?mg/kg), nickel (153.0?mg/kg) and zinc (30.4?mg/kg) in soils around the mining area were considerably higher than those around the landfill (4.3, 0.91, and 13.7?mg/kg, respectively, for copper, nickel and zinc). The mining area was moderate to heavily contaminated with copper, nickel and zinc (1?<?I _geo?<?4), whereas the landfill area was moderately contaminated (1?<?I _geo?<?3). In both areas, the level of copper contamination was higher than that of nickel and zinc. Contamination around the mining environment was attributed to mining activities whereas around the landfill area, migration of leachate from the disposed waste could have been responsible.     

云南临沧晚中新世一种水龙骨科植物化石的修订及其生物学意义

云南现代真蕨类植物资源丰富,蕨类植物多样性的地史起源,必须从化石记录入手。在云南临沧上中新统邦卖组植物化石采集中发现了槲蕨属1块不育叶和2块腐殖叶的新材料,这些标本为修订Drynaria propinqua Wen et al.,2013,以及揭示该种不育叶和腐殖叶的特征提供了新的材料。通过与槲蕨属国内外报道的化石种和现生种的详细比较,将其重新定名为Drynaria cf.propinqua。Drynaria cf.propinqua的发现,表明云南临沧晚中新世的气候与现今中国西南地区温暖湿润的气候类似,这些附生植物的生活习性表明,临沧地区复杂分层的森林生态系统至少在晚中新世已经确立。     

Effects of copper mining on heavy metal contamination in a rice agrosystem in the Xiaojiang River Basin,southwest China

Metallic ore mining causes heavy metal pollution worldwide. However, the fate of heavy metals in agrosystems with long-term contamination has been poorly studied. Dongchuan District (Yunnan, southwest China), located at the middle reaches of the Xiaojiang River, is a well-known 2000-year-old copper mining site. In this work, a survey on soil heavy metal contents was conducted using a handheld X-ray fluorescence instrument to understand the general contamination of heavy metals in the Xiaojiang River Basin. Furthermore, river water, soil, and rice samples at six sites along the fluvial/alluvial fans of the river were collected and analyzed to implement an environmental assessment and an evaluation of irrigated agrosystem. V, Zn, and Cu soil levels (1724, 1047, and 696 mg·kg⁻¹, respectively) far exceeded background levels. The geo-accumulation indexes (I_geo) showed that cultivated soils near the mining sites were polluted by Cd and Cu, followed by Zn, V, Pb, Cr, Ni, and U. The pollution index (Pi) indicated that rice in the area was heavily polluted with Pb, Cr, Cd, Ni, Zn, and Cu. The difference in orders of metal concentrations between the soil and rice heavy metal contamination was related to the proportion of bioavailable heavy metals in the soil. The crop consumption risk assessment showed that the hazard quotient exceeded the safe threshold, indicating a potential carcinogenic risk to consumers. The Nemerow integrated pollution index and health index indicated that the middle of the river (near the mining area) was the heaviest polluted site.

     

Biogeochemical studies at the Khetri copper deposits of Rajasthan,India

Several plants of the Khetri Copper Deposits of Rajasthan (India) accumulate very high levels of copper. The maximum concentration namely 394 ,μg/g (dry wt.) was found in the leaves of Talinum portulacifolium. Some other copper accumulators with the concentration of the metal in μg/g are: Tephrosia villosa (288), Rhus mysorensis (234) and Bouchea morubifolia (147). The respective biological absorption coefficients (copper in dried plant divided by copper in soil) for these four plants were 0.07, 1.35, 0.13 and 0.26, respectively. Leaves were found to be richer in copper than the stems. Copper levels in the leaves of Tephrosia villosa, Aerua tomentosa and Bouchea morubifolia showed a significant (linear) plant/soil relationship. Rhus mysorensis and Talinum protulacifolium showed absorption barriers at high soil copper concentrations, indicating limits to uptake in these two species.     

四川省会理县拉拉地区铜矿山开发生态环境影响评价

本文对四川省拉拉铜矿矿区噪声、水质、土壤、大气等各方面的检测数据进行了分析,阐述了矿区的主要环境地质问题：矿区家属区噪声污染较严重,选矿厂附近大气污染集中在,水质污染主要源于尾矿库渗透;并提出了矿区环境保护建议。     

The natural enrichment of ferruginous weathering products and its implication for water quality in the Hunchun Basin, China

In order to evaluate the extent of a natural enrichment of Fe and Mn over the whole of the Hunchun Basin, the stability of Fe-Mn mineral phases, their status, the weathering rate of source materials, and soil characteristics were determined. A variety of samples were collected from sediments, soil profiles, and surface soils. In the solutions after a sequentially selective dissolution using sodium pyrophosphate (p), acid oxalate (o), and dithionite-citrate-bicarbonate (d), Si, Al and Fe were dominant in the d and p fractions, and Mn in the o and p fractions. The results showed that the existing phases and status of Fe and Mn were distinctly different, and that the abundance of amorphous Mn phases made thermodynamic calculation difficult. An application of these ferruginous weathering products was therefore made to understand basin development. The first terrace of the Hunchun River is more active than the second terrace, which can be inferred from it having a higher value in Fe_d/Fe_t. Amorphous Fe phases such as Fe(OH)₃ and Fe₃(OH)₈ were controlling factors of Fe in the thermodynamic calculations. The transformation of the amorphous Fe phases to more stable phases was hindered by high contents of smectite and gibbsite, amorphous opaline produced from rice roots, and organic phosphate pesticides or fertilizers in soils. Source-rock deduction using water samples suggested granitic weathering. Precipitation around the Hunchun Basin is gradually becoming more acidic. Therefore, in the future it is inevitable that ecological and environmental problems related to the Fe phases mentioned above will occur in the drinking water supply for this area, especially in that of the first terrace.     

Phytoremediation potential of native plants grown in the vicinity of Ahangaran lead–zinc mine (Hamedan,Iran)

This study aims to assess the extent of metal accumulation by plants found in a mining area in Hamedan Province in the central west part of Iran. It also investigates to find suitable plants for phytoextraction and phytostabilization as two phytoremediation strategies. Plants with a high bioconcentration factor (BCF) and low translocation factor (TF) have the potential for phytostabilization while plants with both BCFs and TFs greater than one have the potential to be used for phytoextraction. In this study, shoots and roots of the 12 plant species and the associated soil samples were collected. The collected samples were then analyzed by measurement of total concentrations of trace elements (Pb, Zn, Mn and Fe) using atomic absorption spectrophotometer. Simultaneously, BCF and TF parameters were calculated for each element. Results showed that although samples suitable for phytoextraction of Pb, Zn, Mn and Fe and phytostabilization of Fe were not detected, Scrophularia scoparia was the most suitable for phytostabilization of Pb, Centaurea virgata, Echinophora platyloba and Scariola orientalis had the potential for phytostabilization of Zn and Centaurea virgata and Cirsium congestum were the most efficient in phytostabilization of Mn. Present study showed that native plant species growing on contaminated sites may have the potential for phytoremediation.     

Discrimination of lithogenic and anthropogenic sources of metals and sulphur in soils of the central-northern part of the Zambian Copperbelt Mining District: A topsoil vs. subsurface soil concept

Samples of topsoil together with reference samples of subsurface soil from a depth of 80–90 cm were collected in the central-northern part of the Zambian Copperbelt to distinguish lithogenic sources of metals from anthropogenic contamination of soils caused by fallout of dust from mining operations, flotation ore treatment plants, tailings dams, smelters and slag dumping grounds. The total sulphur, Cu and Co contents were found to be significantly higher in topsoil relative to subsurface soil over a large part of the surveyed area, and Zn, Pb, As and Hg contents showed a definite increase in the close neighbourhood of smelters and in the direction of prevailing winds. This indicates that the increase of these elements in the topsoil is due to anthropogenic activities. The areal extent and degree of anthropogenic contamination of topsoil can be expressed by an enrichment index (EI) based on the average ratio of the actual and median concentrations of the given contaminants. Although the contamination of soil by dust fallout decreases progressively with depth in the soil profile, in areas strongly affected by mining and mineral processing the anthropogenic contamination by sulphur and copper can be traced to a depth of 80–90 cm. In contrast, the concentration of elements such as Cr, Ni, and V, that show a direct correlation with the content of iron in the soils, increases in the subsurface soil relative to the topsoil. This is particularly evident in areas underlain by rocks of the Katanga Supergroup.     

Geochemistry of the Jinman Vein—Type Copper Deposit,Western Yunnan Province,China——I.Element Geochemical Characteristics

The Jinman copper deposit,which is situated on the northern margin of the Lanping-Simao back-arc basin,western Yunnan Province,is a silver-bearing,high-grade vein-type copper deposit.Comprehensive element geochemical studies of the host rocks and hydrothermal minerals revealed the regularities in the distribution,mobilization and transport of elements from the host rocks to hydrothermal minerals.In conjunction with the fluid inclusion and isotope data,it is suggested that the ore-forming fluid was derived mainly from a deep source characterized by CO2 enrichment and reduction in nature.It is also suggested that the oreforming materials come largely from a deep source.although the contribution of the country rocks should not be ruled out.It is also found that some hydrothermal minerals are possessed of MREE-enrichment patterns.It is deduced that the REEs in the deep-source ore fluid were transported in the form of CO3^2- complexes and were deposited in a continental basin(or a hot-spring basin).     

An approach to the classification of Utah mine spoils and tailings based on surface hydrology and erosion

The physical similarities among mine spoils may be strongly influenced by the geologic source of the spoils where overburden is produced from areas of simple geologic structure. Textures and bulk densities are influenced by the methods of handling the materials during mining and disposal operations. Where these influences are the same in more than one mining site, surface hydrology and erosion parameters are often similar. A specific tailing deposit may be highly variable with respect to the physical and chemical characteristics produced by methods of ore treatment and concentration. This variability makes it difficult to classify tailings based on surface hydrology and erosion. Hydrologic characteristics of spoil deposits as related to future successful rehabilitation may be improved by (1) conducting mining activities to permit identification and segregation of favorable overburden strata for use in revegetation, (2) reconstituting soil for optimum plant growth, (3) shaping spoils to be compatible with surrounding topography, (4) mulching with organic materials, and (5) avoiding or ameliorating compaction of the soil-spoil surface. Mr. Burton is currently hydrologist with the Bureau of Land Management in Lewiston, Montana, U.S.A.     

^40Ar／^39Ar Fast Neutron Activation Ages of Quartz from the Jinman Vein Copper Dposit in Western Yunnan and Their Significance

Quartz samples collected from the Jinman vein copper deposit in the Lanping Basin of western Yunnan were determined by⁴⁰Ar/³⁹Ar fast neutron activation techniques, and the spectra are characterized as being saddle-shaped. The samples yielded a plateau age of 58.05 ± 0.54 Ma, a minimum appearance age of 56.76 ±0.81 Ma and an isochron age of 54.30 ± 0.15 Ma, the three ages being close to each other, indicating that the ages of the quartz samples so far determined are true and reliable. The plateau age represents the time of formation of Cu-bearing quartz veins, which is corresponding to Early Himalayan. This age is also consistent with the time at which a tectonically thermal event (60 Ma) took place within the Lanping Basin, Yunnan Province. In consideration of the fact that copper ore and other ore types in the vast area of western Yunnan are concentrated mainly in the Early Himalayan strata, the authors believe that there must have existed some indispensable key factors leading to metallogenesis on a large scale during the Early Himalayan period in western Yunnan and also constraining in union the formation of ore deposits there.     

矿山地质环境问题与治理对策研究——以云南迪庆普朗铜矿一期采选工程为例

矿产资源开发在创造大量财富的同时,也对矿区生态环境产生了严重的负面影响。本文以云南迪庆有色金属有限责任公司普朗铜矿一期采选工程为例,简要分析了临近世界自然遗产"云南三江并流保护区"的普朗铜矿存在的矿山地质环境问题及影响程度,进行了矿山地质环境影响程度分区,同时提出了相应的矿山地质环境保护与恢复治理措施。     

Use of mine spoils from Teruel coal mining district (NE,Spain)

Coal mine restoration projects increase public perception of mining companies. Spain has relatively few examples of completed opencast mine rehabilitation projects. This study seeks to obtain the use of mine spoils from coal mines in Teruel. The studied mine spoils may be used as raw material for the Spanish ceramic industry, located in the provinces of Castellon, Valencia and Teruel. This study specifically discusses the mineralogical and geochemical characteristics of the Lower Cretaceous materials from coal deposits in Estercuel basin, around Teruel and Castellon in Spain. These provinces have a large ceramic industry. A characterization of mine spoils from coal deposits has been carried out. This characterization is based on the data of both mineral and chemical analysis. The mineralogical characterization was complemented with SEM/EDAX. The study of the chemical composition allows the evaluation of the applicability of the studied mine spoils to the following industries: refractory, fine clay, red clay for pavement and coating, and heavy clay. The clay used for refractory industry has the highest compositional demand. The positive results obtained on this set of preliminary tests lead us to envisage new research programs, focusing on testing these mine spoils on a semi-industrial scale.     

Arsenic in soil and vegetation of a contaminated area

Plant and soil samples were collected from one uncontaminated and four contaminated sites (in the Dashkasan mining area western Iran). Total and water-soluble arsenic in the soil ranged from 7 to 795 and from 0.007 to 2.32 mg/kg, respectively. The highest arsenic concentration in soil was found at the ore dressing area (up to 1,180 mg/kg) and lowest at an uncontaminated area (up to 11 mg/kg). A total of 49 plant species belonging to 15 families were collected from four sampling sites. A significant positive correlation was detected between the concentrations of arsenic in plant dry matter and those in soils. The highest arsenic concentrations were found in Hyoscyamus kurdicus Bornm. (up to 205 mg/kg) and Helichrysum oligocephalum DC. (up to 162 mg/kg). These two accumulator species could have potential for soil clean-up by phytoextraction. The data have been compared with those for the Zarshuran mining area (north-western Iran) obtained in a former study.     

Reaction of soil enzymes and spring barley to copper chloride and copper sulphate

Study was carried out to compare the effect of the degree of contamination of soil with copper on the soil enzyme activity, depending on the type of chemical compound with which a metal reaches the soil and on the method of soil use. An effect of increasing doses of copper on growth and the development of spring barley has been studied. The study was carried out as a pot experiment on two types of soil: loamy sand and light loam. Copper was introduced to soil as copper(II) sulphate(VI) and copper(II) chloride at four doses: 150, 300, 450 and 600 mg Cu²⁺ kg^?1 d.m. of soil. Soil without copper was used as a control sample. The experiment showed that contamination of soil with copper applied as CuCl₂ and CuSO₄·5H₂O upset the homeostasis of soil. Dehydrogenases and urease were the most sensitive to contamination of soil with Cu²⁺, both as copper(II) chloride and as copper(II) sulphate(VI), and acid phosphatase and alkaline phosphatase were the least sensitive. Greater changes in enzymatic activity were observed in loamy sand than in light loam. The differences in the impact of copper(II) sulphate(VI) and copper(II) chloride on the soil microbiome were relatively small, because mean ED₅₀ for copper(II) chloride was 341 mg Cu²⁺ kg^?1 d.m. of soil, and for copper(II) sulphate(VI) it was 364 mg Cu²⁺ kg^?1 d.m. of soil. This inhibitory effect of copper persisted throughout the period of the experiment. The sensitivity of spring barley to copper compounds was lower than the enzymes under study.     

Identification of Cu and Ni indicator plants from mineralised locations in Botswana

Plant species that accumulate high levels of metals in proportion to the metal content in the soil are of considerable interest in biogeochemical and biogeobotanical prospecting. This study was aimed at investigating copper and nickel accumulation in the plants Helichrysum candolleanum and Blepharis diversispina, to assess their potential use as mineral indicators in biogeochemical prospecting. Soils and plants were collected from copper–nickel mineralised areas in Botswana. Analyses of the soils and the respective plant parts (roots, stem, leaves and flowers) were carried out using ultrasonic slurry sampling electrothermal atomic absorption spectrometry (ETAAS), which allowed rapid determination of copper and nickel in small amounts of the samples.The metal concentration in the soil was in the range ≈ 40 μg/g–4% (w/w) for Cu and ≈ 60 μg/g–0.3% (w/w) for Ni. The concentration ranges of the elements in the plant parts were ≈ 6 μg/g–0.2% Cu and ≈ 3–210 μg/g Ni. At high soil metal content (greater than 2.5% (w/w) Cu and 0.1% (w/w) Ni), high levels of both nickel and copper were found in the shoots (leaves and flowers) of H. candolleanum. Concentrations as high as 0.2% (w/w) Cu were found in the leaves and flowers of H. candolleanum, indicating hyperaccumulation for this plant. For B. diversispina, the metal concentrations did not exceed 100 μg/g for any plant part, for both metals. Both plant species tolerate high concentrations of metals and should therefore be categorized as metallophytes. In order to evaluate metal translocation from the soil to the shoots, metal leaf transfer coefficients (ratio of metal concentration in the leaf to metal concentration in the soil) were calculated. Our data suggest that the two plant species have different metal uptake and transport mechanisms, which needs to be investigated further. The present work also suggests that H. candolleanum may be used as a copper/nickel indicator plant in biogeochemical or biogeobotanical prospecting.