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1.
Mercury concentrations of four Australian stratiform lead-zinc-silver deposits of Proterozoic age are not directly related to their metamoprhic grade and are probably determined by local factors. Average mercury contents of H. Y. C. mineralization (unmetamorphosed) is 1300 ppb, Mount Isa ore (greenschist facies) 8300 ppb, Squirrel Hills mineralization (amphibolite facies) 100 ppb, and Broken Hill ore (granulite facies) ranges from 1000 ppb for A lode to 37000 ppb for No. 3 lens. In present-day sulfidic muds from the Coorong region of South Australia, mercury is present as mercury sulfide either as inclusions or chemisorbed on mackinawite. This may be analogous to the manner of mercury occurrence in sediments which predated the ingress of lead-zinc-silver mineralization into ancient basins. In bedded H. Y. C. mineralization mercury is present principally in pyrite, but recrystallized mineralization contains mercury in both sphalerite and pyrite. In bedded Mount Isa ore mercury is present in sphalerite, but in remobilized ore which is enriched in galena, freibergite and pyrrhotite, it occurs in both sphalerite and freibergite. Mineralization from Squirrel Hills contains no tetrahedrite, and sphalerite is the host for most mercury. Normal Broken Hill ore contains mercury parti tioned approximately evenly between sphalerite and tetrahedrite, but mercury is enriched in remobilized ore. Veins generated during retrograde metamorphism of the Broken Hill lodes contain high levels of mercury, and multiple veins produced in this fashion around other deposits could result in mercury haloes that can be detected during exploration programs. The way mercury is held in stratiform leadzinc-silver deposits, and the lack of decrease of mercury contents with increasing metamorphic grade, rules out total loss of mercury during metamorphism. Primary mercury haloes around this type of mineralization are due to mercury in disseminated ore-forming minerals or late-stage vein systems contain secondary mercury-bearing minerals.  相似文献   

2.
万山汞矿区汞质沉积成因研究   总被引:2,自引:0,他引:2  
花永丰 《矿床地质》1987,6(3):68-76
万山汞矿是典型的层控矿床,属沉积改造成因。矿质主要来自围岩。从寒武纪初至寒武纪末,形成了一个完整的沉积成矿系列,即形成磷、镍、钒、银、钾、汞、铅、锌、金等的沉积或沉积改造矿床。不仅在沉积岩中,而且在一些典型的沉积矿物、生物化石、生物礁中都有高丰度的汞、铅、锌、砷、锑,在三叶虫化石中含汞最高达100ppm。从矿物的结构构造特征方面也可找到沉积汞的证据,典型的沉积辰砂与热液辰砂大有区别,并发现极少数微粒辰砂赋存在透镜状褐铁矿结核的中心。各方面的资料说明,沉积岩中分散状态的汞质是沉积成因的。  相似文献   

3.
Secondary mercury dispersion haloes were detected and defined above sulphide mineralization by in-situ mercury in soil gas measurements. The meteorological factors controlling the concentration of mercury in soil gas were investigated by long-term experiments. Different mercury compounds in soils and rocks have been determined by a thermal destruction technique. In areas with sulphide mineralization, adsorbed mercury, HgCl2, HgS, HgSO4 and organically fixed mercury are the most important mercury compounds. The concentrations, transport and secondary formation of mercury and its compounds is controlled by: (1) the content of organic matter, Fe-oxides/hydroxides and clay minerals of the soils; and (2) the composition of the underlying rocks.The occurrence of mercury-sulphur compounds indicates the topographic influence on down-slope dispersion and the direction of inclination of the ore body. HgS and HgSO4 are the dominant mercury compounds in the ore; in the bedrock, mercury occurs mainly as adsorbed mercury.  相似文献   

4.
Massive sulfide deposits in the Pacific and Ural provinces have varying mercury contents. The latter is lower in metamorphosed ores than in unmetamorphosed or in young ones. Two varieties of cenozoic sulfide ores are distinguished: 1) products of subcontinental solfataric action with high mercury content in pyrites, accompanied by cinnabar, 2) products of postvolcanic activity in submarine suites with low mercury content in sulfides (Kurokotype). A distribution of mercury between coexisting sulfides (in descending rank) corresponds to the sequence: sphalerite-chalcopyrite-pyrite. During metamorphism, sulfides loose their mercury (pyrite in higher degree than chalcopyrite). It is possible that mercury vaporised from sulfides has some influence on the formation of mercury ores at some distance from metamorphosed sulfide bodies within the same region.  相似文献   

5.
系统采集淮北卧龙湖煤矿岩浆蚀变煤层中岩浆岩、煤及顶底板岩石样品,测试分析了样品中汞、灰分、挥发分、水 分以及各形态硫的含量,探讨了岩浆蚀变煤层中汞的分布与赋存特征。结果表明:(1) 岩浆侵入导致煤中灰分升高,挥发 分降低,煤中硫主要以黄铁矿硫和有机硫存在;(2) 岩浆侵入导致煤中汞的富集,卧龙湖煤矿岩浆蚀变煤层中汞的平均含 量高达0.23×10-6,是华北石炭-二叠纪煤、中国煤以及美国煤中汞的平均含量的1.4 倍,1.2 倍和1.3 倍;(3) 煤中汞的含量 随离岩浆侵入体距离增大有逐渐降低的趋势,但在煤岩接触带附近,汞在岩浆侵入体上方和下方的煤中呈现不同的分布特 征;(4) 煤中的汞主要以无机结合态的形式存在,且大部分赋存在煤中的黄铁矿中,同时亦存在与有机硫结合的汞。岩浆 热液对煤层的侵入,导致煤质以及煤中汞的含量和赋存方式发生了显著变化。  相似文献   

6.
This paper presents chemical analyses of mercury in 123 specimens of 58 meteorites. A statistical comparison is made of the mercury content in meteorites (using all available data) as a function of their composition and texture.The average mercury abundance in stony meteorites is estimated as 6.6 ppm. Stony and iron meteorites differ significantly in mercury content. Among stones, chondrites and achondrites show significant differences in the mercury content. In ordinary cbondrites, mineralogy and texture do not seem to have a significant influence on the distribution of mercury, judging from the available number of analyses. Carbonaceous chondrites, in which we found up to 500 ppm mercury, stand out among all other varieties of chondrites. Iron meteorites fall at the other extreme, having the lowest mercury concentrations (generally 0-0x ppm). In specimens of several meteorite classes, troilite is a good mercury concentrator, having a consistently higher mercury content than the meteorite as a whole. Nonetheless, troilite generally accounts for less than one-half the total mercury content of the meteorite.  相似文献   

7.
受历史汞矿开采活动影响,万山汞矿区稻田遭受了严重的汞污染。为了查明万山汞矿区稻田土壤的汞污染现状以及评估其环境质量改善情况,系统采集了受汞矿区影响的五条主干河流沿岸稻田土壤进行汞含量分析,评价总汞和甲基汞污染程度及其生态风险,并与2008年以来该区域稻田土壤汞数据进行对比。结果表明,研究区稻田土壤的总汞含量为0.21~207 mg/kg,几何平均值为(4.26±4.83)mg/kg;甲基汞含量为0.42~13μg/kg,几何平均值为(1.81±1.93)μg/kg。59%的稻田土壤处于重度汞污染,75%的稻田土壤存在极强的汞潜在生态风险。与已往数据相比,稻田土壤汞含量在2012年后呈下降趋势,基本反映了当地汞防治措施的执行效果。为了避免稻田土壤汞污染引起的安全健康风险,今后应采取除污染源治理以外的土壤修复措施或风险管控措施。  相似文献   

8.
This study assesses the level of contamination of Hg in farmland soils along the irrigating channel downstream from Guizhou Organic Chemical Factory (GOCF), where metallic mercury is used as a catalyst to produce acetic acid. The total input of mercury into the environment, as announced by GOCF, is 140 t in the past 30 years (1971-2000). Sampling sites were chosen based on the distance from the source of pollution--the chemical factory. A total of 39 samples were collected from the study area and analyzed for total mercury concentrations and methyl mercury concentrations. The characteristics of vertical and horizontal distributions of total mercury and methyl mercury in the study area (farmland) are described in this paper. Much attention was paid to the transformation of inorganic Hg into organic mercury species in soils as well. The results showed that the farmland has been heavily contaminated by Hg. Land cultivation activity, land utilization style and distance from the pollution source could be the dominant factors controlling the distribution of THg and MeHg. It is observed that active transformation of inorganic Hg into organic mercury species (MeHg) usually takes place in paddy soils.  相似文献   

9.
郭清海  吴启帆 《地学前缘》2020,27(1):103-111
汞是环境中典型有害组分,深部地热系统可能是环境中汞的重要来源之一,但当前地热成因汞的研究程度很低。本文以腾冲火山带热海水热区为研究区,开展了热泉中汞的水文地球化学研究。热海水热区内排泄的中性热泉含有异常高浓度的汞,但酸性热泉则绝大多数未检出汞。热海热泉中的汞与典型的岩浆来源组分氯相同,均主要来源于岩浆流体的混合。在中性热泉中,Hg(II)是汞的占优势地位的价态,Hg2+与不同形态硫化物的配合则是决定Hg(II)的形态分布的直接因素,但pH可通过控制水中硫化物的形态分布来影响Hg(II)的形态分布。Hg(II)不易挥发,故中性热泉中汞含量普遍较高;但酸性热泉中的汞受泉口氧化还原电位较高的影响,以Hg(0)为主要价态,且因Hg(0)易挥发而导致总汞含量极低。就中性热泉而言,其汞含量对水热区断裂分布有重要指示作用,原因为沿不同断裂上升的中性地热水经历的冷却方式不同,最终导致热泉汞含量也表现出显著差异。热泉汞含量对水热系统结构研究有借鉴意义。  相似文献   

10.
水生生态系统中汞-硒相互作用研究进展   总被引:1,自引:1,他引:0  
甲基汞是汞存在于水生生态系统(水体、沉积物和水生生物)毒性最强的形态,并通过食物链的传递对生物体产生危害,因此有效控制汞的甲基化过程是汞环境化学和毒理学研究的重要课题。生物体内硒对汞的甲基化过程有明显的抑制作用,明确汞和硒在水生生态系统的形态特征以及汞-硒相互作用机制,有助于解决汞污染问题。汞在生物体内的毒性与生物体内硒含量紧密相关,汞与硒相之间的相互作用主要表现在生成不溶的化合物促使汞去甲基化或受生物体内硒相关酶抑制被直接排除于生物体外,从而抑制了汞的毒害作用。本文评述了汞、硒在水生生态系统中的形态特征,指出在水体中合理添加硒化合物可抑制无机汞在生物体内甲基化过程,深入研究生物体内汞和硒相互作用机制及其生理效应是该领域未来发展方向。  相似文献   

11.
 Understanding the mechanisms of mercury evaporation from soil to the atmosphere is necessary for tracing the fate of mercury in the biological environment and for assessing potential health effects and the impact of anthropogenic mercury emissions on the environment. In this article an integrating overview of the current knowledge of the mechanisms of mercury evaporation is presented. Abiological and biological formation of Hg(0) and/or (CH3)2Hg in the uppermost soil layers are the rate limiting processes of mercury evaporation from soils in background areas; the evaporation rate in background areas is probably strongly influenced by deposited airborne mercury. The evaporation rate limiting factors in mercury enriched mineralized areas with large fractions of total mercury being volatile mercury species (relative to background soil in the non-mineralized vicinity) meteorological variations and the transport characteristics of soils for volatile mercury species. Mercury evaporation rates from background soils are usually <0.2 μg·m–2·h–1 and significantly smaller than from mercury-enriched mineralized areas. Received: 20 November 1995 / Accepted: 24 July 1996  相似文献   

12.
钟勇 《岩矿测试》2001,20(2):145-146
将试样置于潘菲氏管中加入还原铁粉,加热使汞与基体及共存元素分离,继而试验了汞蒸气-原子荧光光谱法测定汞的最佳条件,汞的检出限为0.05μg/L,线性范围为0.5~250μg/L,回收率为94.6%~102.5%。方法已应用于锌精矿中汞的测定,RSD(n=5)<1%。  相似文献   

13.
pH 值对包气带土壤吸附铅和汞的影响实验   总被引:5,自引:0,他引:5  
本文测定了北京西郊4组不同包气带土壤中铅和汞的含量,探讨了pH值变化对铅和汞在土壤样品中分配系数的影响。结果表明:随着pH值的升高,汞和铅在土壤中的分配系数逐步增大,随后降低,pH值与分配系数关系曲线为单峰曲线。汞在砂壤土、轻壤土和中壤土中的分配系数Kd值在0~160mL/g之间,当pH值为10左右时,Kd值最大为160mL/g;铅的分配系数远大于汞,当pH值介于6~10之间时,铅在上述土壤中的Kd值为16 800~29 500mL/g。  相似文献   

14.
渭北石炭二叠系煤中汞的含量及分布特征   总被引:7,自引:0,他引:7  
采用原子荧光和化学分析方法,研究了渭北部分矿区石炭二叠系煤中汞的含量及汞在煤中的分布特征。结果表明,渭北石炭二叠系煤中汞含量较高,高于地壳中汞的平均含量(0.08×10-6)及已经报导的煤和石油中汞的含量(0.001×10-6~0.03×10-6)。煤中汞主要以HgS的形式存在,与煤中无机硫成正比关系。同时论述了煤中汞含量与灰分等的关系。   相似文献   

15.
老厂矿区煤中汞的成因类型和赋存状态   总被引:9,自引:2,他引:7  
老厂矿区无烟煤中的汞有两种成因类型:陆源沉积型和后期矿化叠加型,后者的含汞丰度显著高于前者。低硫煤中汞的主要载体为粘土矿物,高硫煤中为黄铁矿;有机汞含量较低并随煤中黄铁矿含量及其含汞性的增高而增高。根据实测数据计算了不同类型煤中各物质成分的汞丰度;对煤中汞的可造性作了初步评价;预测了燃煤电站排气中汞的平均浓度。   相似文献   

16.
This paper analyses the data on the distribution of mercury in the surface layer of bottom sediments (0–5 cm) obtained in course of sampling trips within the mouth region of the Severnaya Dvina River and the White Sea area. A total of 170 analyses for mercury were performed. Such wide-scale determination of the mercury content in the bottom sediments was carried out for the first time in the study region. The patterns of mercury distribution in the Severnaya Dvina River-White Sea transect are revealed and described. It is shown that the marginal filter of the Severnaya Dvina River facilitates cosedimentation of the main portion of anthropogenic mercury with suspended matter. This drastically decreases the risk of penetration of mercury to the White Sea waters and partially (with the gravity current) to the Barents Sea waters. In general, the Severnaya Dvina River is characterized by mercury pollution of a local scale within the urban territories. No regional pollution of the White Sea off the marginal filter was revealed.  相似文献   

17.
Mercury mobility and bioavailability in soil from contaminated area   总被引:2,自引:0,他引:2  
The mobility and bioavailability of mercury in the soil from the area near a plant using elemental mercury for manufacturing thermometers, areometers, glass energy switches and other articles made of technical glass has been evaluated. Mercury has been determined by sequential extraction method and with additional thermo desorption stage to determine elemental mercury. The procedure of sequential extraction involves five subsequent stages performed with the solutions of chloroform, deionized water, 0.5 M HCl, 0.2 M NaOH and aqua regia. The mean concentration of total mercury in soil was 147 ± 107 μg g−1 dry mass (range 62–393), and the fractionation revealed that mercury was mainly bound to sulfides 56 ± 8% (range 45–66), one of the most biounavailable and immobile species of mercury in the environment. The fractions that brought lower contribution to the total mercury content were semi-mobile humic matter 22 ± 9% (range 11–34) and elemental mercury 17 ± 5% (range 8–23). The contributions brought by the highly mobile and toxic organomercury compounds were still lower 2.3 ± 2.7% (range 0.01–6.5). The lowest contributions brought the acid-soluble mercury 1.5 ± 1.3% (range 0.1–3.5) and water-soluble mercury 1.0 ± 0.3% (range 0.6–1.7). The surface layer of soil (0–20 cm) was characterized by higher mercury concentrations than that of the subsurface soil (60–80 cm), but the fractional contributions were comparable. The comparison of mercury fractionation results obtained in this study for highly polluted soils with results of fractionation of uncontaminated or moderately contaminated samples of soil and sediments had not shown significant statistical differences; however, in the last samples elemental mercury is usually present at very low concentrations. On the basis of obtained correlation coefficients it seems that elemental mercury soils from “Areometer” plant are contaminated; the main transformation is its vaporization to atmosphere and oxidation to divalent mercury, probably mainly mediated by organic matter, and next bound to humic matter and sulfides.  相似文献   

18.
The speciation and partition of mercury in a macrotidal estuary (Seine estuary, France) was studied in order to explore the role of the high turbidity zone (HTZ) in mercury transfer to the adjacent coastal waters. Water and particles were analyzed to determine the concentrations of various mercury species, including monomethylmercury and the inorganic fraction. The exchangeable particulate mercury, which varies with salinity, and the mercury fraction associated with the amorphous oxyhydroxides were evaluated. The distribution of dissolved mercury species during early mixing suggests non-conservative behavior of organically bound mercury at the head of the estuary. Mercury in the particles covaried positively with suspended particulate matter concentrations up to a threshold, which constitutes the typical mercury load of particles and deposited sediments of the HTZ. This distribution pattern is well explained by a dilution model: a slowly settling, low metal population of particle, characterized by relatively invariant turbidity, becomes admixed with a variable amount of higher metal content particles derived from the resuspension in the HTZ. In addition, in the HTZ, which acts as a degradation reactor for particulate organic matter, particulate mercury concentrations increase with increasing C:N ratios and amorphous oxyhydroxides particles. Mercury reaches the estuarine HTZ mainly associated with the riverine and marine particles, including organic matter and oxyhydroxides, which are temporarily trapped in the HTZ and mixed with autochthonous HTZ particles. The largest particles periodically settle and undergo diagenetic reactions and resuspensions, which lead to their mercury enrichment. Depending upon hydrodynamic conditions, mercury escapes seaward as fine particulate within the plume, partially associated with the oxyhydroxides. A surface complexation model reproduces most of the partitioning observed. In the dissolved phase the model simulation suggests that a very strong ligand must be present to explain the field observations.  相似文献   

19.
Mining wastes and calcines from two abandoned mining areas (Valle del Azogue and Bayarque in Almería) have been characterized. In the mining wastes, the dominant mercury phases are cinnabar and elemental mercury in the matrix. In the calcines, however, the dominant mercury phase is elemental mercury bounded to the matrix. Water-leaching experiments were conducted on low-grade stockpiles and calcines in order to simulate the mobilization of mercury by runoff under environmental conditions. The laboratory column-leaching experiments show a possible mobilization of mercury from Hg0 dissolution, colloid transport and a possible dissolution of calomel and other soluble phases in the mine wastes from the Valle del Azogue and Bayarque mines. Equilibrium speciation modeling of Hg, conducted using the numerical code MINTEQ, showed that the theoretical dominant mercury species in the calcine and mining wastes samples are Hg(OH)2, HgCl2, HgClOH and Hg0. In some leachates obtained from the Valle del Azogue mining wastes (sample A06), the high Hg concentrations may indicate the possible dissolution of mineral phases such as calomel and other soluble phases, which are subsaturated. The environmental results indicate a great environmental mobility of mercury, especially during wet episodes associated with intense precipitation events, when there are significative amounts of secondary soluble minerals.  相似文献   

20.
Half a century of mercury research has provided scientists and policy makers with a detailed understanding of mercury toxicology, biogeochemical cycling and past and future impacts on human exposure. The complexity of the global biogeochemical mercury cycle has led to repeated and ongoing paradigm shifts in numerous mercury-related disciplines and outstanding questions remain. In this review, we highlight some of the paradigm shifts and questions on mercury toxicity, the risks and benefits of seafood consumption, the source of mercury in seafood, and the Arctic mercury cycle. We see a continued need for research on mercury toxicology and epidemiology, for marine mercury dynamics and ecology, and for a closer collaboration between observational mercury science and mercury modeling in general. As anthropogenic mercury emissions are closely tied to the energy cycle (in particular coal combustion), mercury exposure to humans and wildlife are likely to persist unless drastic emission reductions are put in place.  相似文献   

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