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苏北榴辉岩中金红石矿床的形成机制探索 总被引:1,自引:0,他引:1
通过对钛的迁移形式和条件的研讨,结合苏北地区的地质背景、有关矿物流体包裹体的化学成分、榴辉岩中有关矿物的化学成分、金红石的赋存状态、含金红石榴辉岩主要矿物组合等情况,认为该类金红石矿床的形成机制可描述为:华北、扬子两大板块碰撞、俯冲,将苏北地区地壳浅部的基性岩等带入上地幔的高温、高压、强还原富氢环境,岩石中部分钛呈氢化物活化。此后,由于地壳运动,榴辉岩折返、抬升,地幔深部的钛氢化物与岩石中活化的钛氢化物随榴辉岩一同迁移至地壳浅部,由于氧逸度大增,压力、温度大降,还原性气体逃逸、氧化,逐渐演化为相对氧化性的环境,钛氢化物被氧化成金红石、沉淀富集成矿。 相似文献
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Liang LU Jing HE Xiangjun PAN 《中国地球化学学报》2006,25(B08):107-107
Grignard regents have been applied extensively in chemical industry, especially in pharmacy. A mass of bromide-containing wastewater was produced after reaction, and ozonation of these organic contaminants can produce bromate and other brominated pollutants. The US Environmental Protection Agency (EPA) has established a maximum contaminant level of 10 μg/L for bromate in finished water. Therefore, it is necessary and significant to remove the DBP (disinfection by-products) precursor - bromide. On the other hand, since the bromine is a valuable element, recovery of it from wastewater is significant. Bromide removal is important to control DBP (disinfection by-products) contaminant and an ion exchange process is one of several treatment processes for this purpose. Layered double hydroxides (LDHs) are useful as adsorbents for bromide removal because of theft ion exchange properties. In this study, the adsorption properties of LDHs for bromide and the method of regeneration of this material were examined. It has been found that the LDHs with Mg/Al molar ratio of 2 represented the highest capacity to remove bromide ion from aqueous solution at pH 6.0. The equilibrium isotherms of uptake of bromide by CLDH were well fitted by the Langmuir equation. Bromide adsorbed on the LDHs was effectively desorbed at 30% Na2CO3 solution and the LDHs were regenerated at the same time. The regenerated LDHs could be reused repeatedly for the bromide removal. Bromide in the exhausted desorption solution was recovered as bromine by oxidation using Cl2. 相似文献
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Based on the principle of synthesis, a new method was put forward to dispose Congo Red anion-containing dyestuff from wastewater and its feasibility was also examined. The principle of the method is described as follows: Mg^2+ and Al^3+ are hydrolyzed to form Mg/Al-LDH by adding Mg^2+, Al^3+ and NaOH in wastewater containing anion dyestuff, which is selectively intercalated with the interlayer of LDH in order to balance positive structural charge. While Mg^2+ and Al^3+ are co-precipitated to form LDH, the anion dyestuff in wastewater will be removed by LDH synthesized in-situ, as is confirmed by X-ray diffraction analysis of settlings and chemical analysis of aqueous samples. In this work, we studied the influence of Mg/Al mole ratio, pH value, time and temperature of reaction on the removal of anion dyestuff and the use of Mg and Al. The experimental results showed the maximum removal efficiency of anion dyestuff could be attained when pH value was 9.0, and Mg/Al mol ratio was 2 : 1, reaction duration was 2 hours, and the effect of temperature was not remarkable, and the removal efficiency could reach 100%. Meanwhile, the Mg and Al added could be made good use of. This technology has the advantage of extraordinary efficiency of wastewater disposal. 相似文献
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During stabilization or demobilization of contaminants in solid waste materials, different approaches can be taken, which also can be combined: (1) sufficient long-term buffer capacity can be provided, according to the environmental conditions; (2) permeability for dissolved contaminants can be reduced by secondary mineral precipitations or by soft gels injected into the pore space of the waste body; and (3) new formations of ‘reservoir minerals' can incorporate potential pollutants in their internal structure. Emphasizing the geochemical engineering approach, two examples are presented from the field of water management, both focussing on the demobilization of arsenic species. The first example (after Driehaus, W., 1994. Arsenentfernung mit Mangandioxid und Eisenhydroxid in der Trinkwasseraufbereitung. Vol. 133, Ser. 15, VDI-Reports, Düsseldorf, 117 pp.) relates to the problems during purification of arsenic-rich raw water, suggesting the potential application of iron and manganese oxide minerals as oxidizing agents and mineral lattice structures for the elimination of arsenic. In the second example, contaminated sludges from water treatment plants were investigated for their leaching characteristics and long-term stability. A pH-stat test procedure was used to assess the leaching characteristics of metals at typical pH values. Due to the presence of iron and manganese oxides pentavalent arsenic is protected against conversion into the mobile trivalent form at neutral to low pH. Experimental data suggest that co-disposal with reducing organic matter and alkaline stabilization material or wastes could negatively influence the binding properties and, therefore, should be avoided. 相似文献
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硼氢化钠还原共沉淀-感耦等离子体质谱法测定岩石样品中痕量钌铑钯铱金和铂 总被引:5,自引:1,他引:5
研究了共沉淀分离富集贵金属元素的条件,选定在pH1.5溶液中,Mn作捕集剂,NaBH4为还原剂,使Ru(Ⅵ)、Rh(Ⅲ)、Pt(Ⅳ)、Pd(Ⅱ)、Ir(Ⅳ)和Au(Ⅲ)贵金属离子还原成金属态沉淀物,沉淀经体积分数为50%的王水溶解后用ICP-MS测定。样品测定限Rh、Ir、Au为1ng/g,Ru、Pt、Pd为2ng/g。方法的RSD(n=10)为10%~25%,经几种岩石标样验证,其结果与标准值相符。 相似文献
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氢氧化镁处理含铬废水的研究 总被引:17,自引:0,他引:17
用硫酸亚铁将废水中Cr(Ⅵ)还原成Cr(Ⅲ),再用氢氧化镁乳液和废水中的酸,使铬离子,铁离子氢氧化物沉淀,澄清分离,这样含铬废水经处理后,铬的含量及pH值有达到排放标准,该方法操作简便,效果显著。 相似文献
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