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51.
过硫酸铵氧化容量法测定矿石中锰方法的改进 总被引:5,自引:1,他引:5
采用过硫酸铵氧化容量法测定锰时,可在低酸度(0.18mol/LH2SO4、0.29mol/LH3PO4)和大体积(300mL)溶液中氧化Mn2 至Mn7 。所测得的结果十分稳定,回收率为100%。采用管理样分析验证方法,其结果与铋酸钠容量法结果一致。对于w(Mn)=11.36%的试样进行10次分析测定,RSD=0.33%。方法可测定w(Mn)≥0.01%的常见矿种样品。 相似文献
52.
Abstract On the basis of the Atterberg indexes of various sediments collected in the Mediterranean Sea, we select two major parameters indicative of the mechanical behavior of marine soils: the sedimentary facies (i.e., mechanism of deposition expressed by silt content) and the clay mineral association characterized by smectite content in the fraction finer than 2 μm. Activity and real thixotropic ability appear to be particularly important parameters in marine engineering; better values are obtained by a double test operation in distilled and marine water. 相似文献
53.
湘西南区氧化锰矿以锰帽型氧化锰矿为主,赋矿地层为震旦系下统湘锰组。其特点是含锰点多,分布面广,矿体在地壳贫化,往下3~7m开始富集,氧化深度40m左右。 相似文献
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Abstract. Chemistry and sulfur isotopes are analyzed for a series of rocks in the chert‐dominant sequence around the stratiform manganese ore deposit of the Noda‐Tamagawa mine in the northern Kitakami Terrane, northeast Japan. The sequence is litholog‐ically classified into six units in ascending order: lower bedded chert, lower black shale, massive chert, manganese ore, upper black shale, and upper bedded chert. The rocks around the manganese ore deposit exhibit anomalous enrichment in Ni (max. 337 ppm), Zn (102) and U (30) in the upper part of lower bedded chert, Mo (122), Tl (79) and Pb (33) in the lower black shale, MnO, Cu (786) and Co (62) in the manganese ore, and As (247) and Sb (17) in the upper black shale. The aluminum‐normalized profiles reveal zonal enrichment of redox‐sensitive elements around the manganese bed: Zn‐Ni‐Fe‐Mo‐U(‐Co), Tl‐Pb(‐Mo), Mn‐Fe‐Cu‐V‐Cr‐Co(‐Zn) and As‐Sb in ascending order. The uppermost part of the lower bedded chert and black shale exhibit negative Ce/Ce* values, whereas the massive chert, manganese ore and lower part of the upper bedded chert display positive values. The isotopic δ34S values are 0±6 % in the lower part of the lower bedded chert, ‐19 to ‐42 % in the upper part of the lower bedded chert, ‐36 to ‐42 % in the lower black shale, ‐28 to ‐35 % in the massive chert, manganese ore and upper black shale, and ‐23±5 % in the upper bedded chert. Thus, there is a marked negative shift in δ34S values in the lower bedded chert, and an upward‐increasing trend in δ34S through the manganese ore horizon. The present data provide evidence for a change in the paleoceanographic environmental resulting from inflow of oxic deepwater into the stagnant anoxic ocean floor below the manganese ore horizon. This event is likely to have triggered the precipitation of manganese oxyhydroxides. The redistribution of redox‐sensitive elements through the formation of metalliferous black shale and manganese carbonate ore may have occurred in association with bacterial decomposition of organic matter during early diagenesis of initial manganese oxyhydroxides. 相似文献
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Abstract Knowledge of the hydrochemical dynamics of the trace metal manganese (Mn) in upland catchments is required for water quality management. Stream water Mn and other solutes and flow were monitored in two upland catchments in northern England with different soils: one dominated by peat (HS7), the other by mineral soils (HS4). Maximum Mn concentrations occurred at different times in the two catchments: in summer baseflow at HS4 and during late summer storm events at HS7. A two-component chemical mixing model was used to identify the hydrological processes controlling Mn concentrations in stream water. This approach was more successful for HS4 than HS7, probably because of different processes of Mn release in the two catchments and also difficulties in selecting conservative solutes. Factor analysis of the stream water chemistry data set for each catchment was more useful in identifying the controls on Mn release into runoff. The factors indicate that the main source of Mn at HS4 is the hydrological pathway supplying summer baseflow, whereas at HS7 Mn is released during the rewetting of dried peat soils. Manganese concentrations in stream water in upland catchments appear to depend on soil type and antecedent moisture conditions. This has implications for the design of sampling strategies in upland catchments and also for managing the quality of water supplies from such areas. 相似文献
58.
Takashi Doi Michiaki Takano Kei Okamura Tamaki Ura Toshitaka Gamo 《Journal of Oceanography》2008,64(3):471-477
We present the results of a chemical survey at a submarine volcano, Teishi Knoll, obtained using a submersible in-situ Mn
analyzer (GAMOS) mounted on an autonomous underwater vehicle (AUV) platform. During this survey, high-resolution data of dissolved
Mn were obtained in three dimensions in nearly real time. The AUV enabled continuous detailed observations along a preprogrammed
pathway, which could not have been performed with conventional CTD hydrocasts. During this observation, anomalously high dissolved
Mn concentrations were obtained within the crater, corresponding to high water temperatures. The anomalies might be a hydrothermal
signature due to volcanic activity from the crater. 相似文献
59.
在黄河小浪底水利枢纽观测孔工程中,采用气动潜孔锤跟管钻进结合双动力头钻机成功地解决了普通气动潜孔锤及常规钻进工艺在厚度达50 m渣石层成孔难的问题。 相似文献
60.
Brian Gulson Karen Mizon Michael Korsch Honway Louie Michael Wu Jenny Stauber J. Michael Davis Alan Taylor 《中国地球化学学报》2006,25(B08):62-62
This is a 4-year longitudinal study to evaluate changes to the environment and exposure of young children associated with the introduction of methylcyclopentadienyl manganese tricarbonyl (MMT) into Australia in 2000. The cohort includes 57 females and 56 males; age range of 0.29 to 3.9 years. Samples are collected every 6 months from children in residences located at varying distances from major traffic thoroughfares in Sydney. Environmental samples: air, house and day care dustfall, soil, dust sweepings and gasoline. Samples from children: blood, urine, handwipes prior to and after playing outdoors, and a 6-day duplicate diet. All samples are analyzed for a suite of 20 elements using ICP-MS. Results are presented for the first three 6-month sampling periods for Pb and Mn. For dustfall accumulation, there was no significant change over the 3 sampling periods (time) for Pb or Mn, and a positive relationship between ‘traffic exposure' (traffic volume and proximity to the road) and Pb but not Mn. For handwipes, Pb and Mn in wipes taken from children after playing outdoors were usually significantly greater than for wipes taken prior to playing. There was no significant association between Pb or Mn in handwipes with traffic exposure. Dustfall accumulation was a significant predictor for Pb in the handwipes, and dust sweepings were a significant predictor of Mn in handwipes. 相似文献