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排序方式: 共有463条查询结果,搜索用时 15 毫秒
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Lithium production in China mainly depends on hard rock lithium ores, which has a defect in resources,environment, and economy compared with extracting lithium from brine. This paper focuses on the research progress of extracting lithium from spodumene, lepidolite, petalite, and zinnwaldite by acid,alkali, salt roasting, and chlorination methods, and analyzes the resource intensity, environmental impact,and production cost of industrial lithium extraction from spodumene and lepidolite. It is fou... 相似文献
275.
The estuarine behaviour of the metal load leaching from acid sulphate (AS) soils was studied in a selected river system (the V?r? River), in western Finland. Large amounts of metals were transported with the river and deposited within the estuary, causing highly elevated metal concentrations in both the sediment traps and in the underlying bottom sediments. Among the metals, there was a diverging deposition pattern where Al, Cu, La and U demonstrated a strong association with organic matter and were deposited within approximately 4 km from the river mouth. In contrast, the deposition of Co, Mn, Ni and Zn occurred when pH reached circumneutral conditions further out in the estuary. Yet other metals were not abundantly leached from the AS soils and thus not elevated in the river and estuary (Fe, Ti, Cr, V). Five separate chemical extractions indicated the geochemical speciation of the metals. 相似文献
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Bioremediation of sulphate rich mine effluents using grass cuttings and rumen fluid microorganisms 总被引:1,自引:0,他引:1
Harma A. Greben Jacobin Baloyi Julia Sigama Stephanus N. Venter 《Journal of Geochemical Exploration》2009,100(2-3):163-168
Acid Mine Drainage (AMD) needs to be treated before it can be re-used or discharged in receiving water bodies due to the low pH, high salinity and high sulphate concentrations of the water. Several treatment methods are currently applied including chemical treatment (e.g. neutralisation of the low pH waters), physical treatment (e.g. reverse osmosis) and biological treatment to reduce the high sulphate concentration. When treating AMD biologically, sulphate reducing bacteria (SRB) reduce sulphate to sulphide, provided that a suitable and cost effective carbon and energy source is present. In the present study mine water was remediated biologically, using the degradation products of grass-cellulose, as carbon and energy sources for the sulphate reducing bacteria. A laboratory scale one stage anaerobic bioreactor (20 L volume) containing grass cuttings and biomass consisting of rumen fluid microorganisms and immobilized SRB, was initially fed with synthetic sulphate rich water and later with diluted AMD. The results indicated an average of 86% sulphate removal efficiency when feeding synthetic sulphate rich feed water to the reactor. When feeding diluted AMD, the highest sulphate removal efficiency was 78%. The sulphate removal was dependant on Chemical Oxygen Demand (COD) concentrations in the reactor. Increased COD concentrations were obtained when fresh grass was added to the reactor on a regular basis. Metal removal, especially iron, was observed due to the metal sulphide precipitates formed during biological sulphate removal. 相似文献
278.
2001年5月23日青海省的一次透雨过程基本解决了春旱问题.此次降水预报准确,开展了飞机人工增雨作业,同时利用一架科研探测飞机对降水云层进行较系统的云微物理特征探测.探测结果表明"5·23"透雨过程中,降水云系在降水形成发展阶段有分层现象,上层云云水含量较下层大,云粒子浓度大,水汽主要由较高层的系统输送,由于青藏高原特有的下垫面条件,云系的发展变化较快.云粒子谱分析表明,降水云系生成阶段,云粒子谱不连续,呈间断分布或呈浓度有多峰的特征,降水云系成熟后云粒子谱明显增宽,且浓度增加一个以上数量级.云系的不同发展阶段降水云系的粒子二维特征也有不同. 相似文献
279.
河南省区域暴雨的客观分型 总被引:3,自引:0,他引:3
从多层聚类分析入手,利用微机对1980~1995 年河南省213 场区域暴雨过程的500 hPa 高度场进行客观分型,得出了4 类天气形势及其与暴雨落区的对应关系。 相似文献
280.
内蒙古雨养农业区土壤水分动态监测模式 总被引:3,自引:0,他引:3
文章根据多年实际观测资料,在土壤水分平衡参数模拟方法的基础上,利用初始土壤有效水分贮存量、降水量和实际蒸散量3要素,建立了0~50 cm土层的土壤水分动态监测模式,确定了各项参数的计算方法。通过11个站点两年的检验和试用,对主要农作物春小麦和春玉米农田的水分状况监测准确率达80%以上。同时,对两个站点的土壤水分进行了预报,准确率平均为92%。 相似文献