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201.
The role of chloride ions in metal sulfides leaching has been well established by researchers, the complexation of chloride ions was considered to be the main effect of chloride ions. In this work, the complexation of chloride ions was neglected by addition of EDTA, a strong complexing agent. In this way, further study was conducted on the effect of chloride ions. The increase of chloride ions concentration from 0 to 2 mol/L, decreased the open circuit potential of pyrite from 264 to 91 mV. Unless otherwise stated, all potentials in this paper are based on the potential of saturated calomel electrode. At 600 mV, the increase of chloride ions concentration acceleraed pyrite oxidation; at 800 and 1000 mV, however, the increase of chloride ions concentration lowered pyrite oxidation rate, and the proportion of elemental sulfur was also decreased with increasing chloride ions concentration; when chloride ions concentration increased from 0 to 2 mol/L, the proportion of elemental sulfur decreased from 32% to 28.4% at 800 mV, and 7.1% to 2.4% at 1000 inV. 相似文献
202.
基于矿床模型综合地质信息法原理,结合砂岩型铀矿特征,总结了一套适用于砂岩型铀资源评价的方法体系,并以伊犁盆地南缘层间氧化带型铀矿为例,通过资料的收集、整理与分析,预测评价模型的建立,预测变量的构置与筛选,成矿有利度计算及最小预测区圈定,资源量估算等5方面的示范,定位定量地对伊犁盆地南缘层间氧化带型铀矿进行了资源评价。 相似文献
204.
205.
CHEN Gang QING Chengsong CHEN Tianhu LI Xiaoxuan SONG Yinxian PENG Shuchuan 《《地质学报》英文版》2006,80(2):257-261
Decoloration of acidic scarlet GR by pyrolusite is studied in this paper. The effects of pH in solution, dosage and granularity of pyrolusite, reaction temperature, and vibration speed on decoloration efficiency are discussed. According to experiment results, the decoloration efficiency may exceed 95% for 40 mg/L GR solution by pyrolusite. pH is most important among all factors which impact the decoloration of acidic scarlet GR. Dosage and granularity of pyrolusite, reaction temperature, and vibration speed have a little benitfit on decoloration. The high decoloration efficiency and low removal efficiency of COD as well as FT-IR spectra of products between pyrolusite and acidic scarlet GR indicate that acidic scarlet GR undergoes the redox reaction on the interface of mineral and its chromophore is oxidated and decolored, but it is not removed thoroughly by oxidation. 相似文献
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207.
地下水的EhW值是反映其氧化还原能力的水文地球化学参数,是确定铀氧化还原环境必不可少的参数之一。在准噶尔盆地东部进行1∶50万层间氧化带砂岩型铀矿床区调时,受工作条件限制,没能对所采集到的水样进行EhW值测定,因而影响了对水的氧化还原能力的评价,但是这批水样分析资料中的Fe2+/Fe3+是非常有用的氧化还原电对,可用来模拟计算地下水环境的EhW值。详细讨论了应用地球化学模式来模拟计算地下水EhW值的原理和结果。 相似文献
208.
安微淮南潘北煤矿–580 m水平探4孔与ES1C3上3-1孔在疏放太原组灰岩水时带有臭鸡蛋气味,且水流过程中伴有白色絮状漂浮物。通过采集水样,测试了出水孔水质及气体,分析了其形成原因。结果表明:气体为H2S,两出水孔的水质均具有低SO2–4、高HCO–3、弱碱性特征,白色絮状物为有机质和钙、镁物质的结合,该异常现象是脱硫酸与脱碳酸共同作用的结果。为及时处理异味对井下作业环境的影响,采用纳米二氧化钛–紫外光催化氧化法在室内对水进行硫化氢去除试验,其去除率为80%~90%,效果显著。 相似文献
209.
In order to understand the response of authigenic pyrite to gas hydrate geo-systems, pyrite tubes or rods at the sulfate–methane transition (SMT) zone of core GC10 from the northern continental slope of the South China Sea (SCS) were investigated. In situ X-ray diffraction (XRD) results show that the pyrite tube consists of pyrite micro-crystals with trace amount of graphite in the inner tube. Scanning electron microscope (SEM) observations of pyrite tubes indicate various aggregations in the form of framboidal, euhedral, and colloidal pyrite microcrystals. Typical framboidal pyrite is considered as packing of octahedral microcrystals. Interestingly, many framboids in the tubes consist of round or irregular microcrystals and have an outer crust that consists of secondary pyrite. The size of the framboids in the inner wall of the tube is larger than that in the middle wall or foraminifer-filled pyrite. High-resolution transmission electron microscopic (HRTEM) images show marcasite lamellae defects in the spherulitic pyrite crystals, which reveal different solution conditions during the pyrite precipitation. Nano-foil-like graphitic carbon was observed to be closely associated with the pyrite spherules. The occurrence of both marcasite layers and nano-foil-like graphitic carbon suggest that the migration of methane from deep sediment. It is suggested that the formation of pyrite serves as a catalyst during the reaction from methane to elemental carbon under the anaerobic oxidation of methane. Meanwhile, this reaction results in local acidification of the solution inside the pyrite tubes, which favors marcasite lamellae growth on the host pyrite substrate. 相似文献
210.
本文论述了电子顺磁共振法测量岩石中结晶石英的顺磁中心浓度──辐射损伤法在层间氧化带砂岩型铀矿床中的应用;在层间氧化带中,氧化带岩石中的石英顺磁中心浓度高,铀含量低,即辐射损伤大,古轴量高,而氧化-还原过渡带中的石英顺磁中心浓度低,铀含量高,表明铀源来自氧化带岩石。由此可以探讨矿床成因和成矿物质来源,并用于找矿和成矿预测工作。 相似文献