湘南地区稀土矿产资源开发经济意义探讨

湘南地区风化壳型稀土资源丰富，对其开发的采、选工艺和流程简单，投入资金较少，产出颇丰、经济、社会效益明显，是湘南盆困山区脱贫致富的重要途径。本文就开发湘南稀土矿的成本、效益等进行了初步测算，可供参考。     

中国北西部地区地浸砂岩型铀矿床的成矿条件与分布规律

中亚地区发现大量可地浸砂岩型铀矿床引起了我国的重视 ,目前正在积极开展此类型铀矿的找矿工作。我国北西部是寻找类似中亚地区层间氧化带后生地浸砂岩型铀矿床最理想的地区 ,本文在论述了区域大地构造特征、地壳演化与区域铀成矿带形成的基础上 ,着重阐明了区域中新生代盆地地浸砂岩型铀矿床形成的铀源条件、盆地类型与结构及富铀性对形成地浸砂岩型铀矿的影响 ;并以区内已有层间氧化带地浸砂岩型铀矿床为例 (伊犁盆地、二连盆地与测老庙盆地砂岩型铀矿床 ) ,论述了盆地砂岩型铀矿床形成的岩相古地理条件、水文地质与层间氧化带发育条件及对铀成矿的影响 ;并阐述了本区层间氧化带地浸砂岩型铀矿床的分布规律     

陕西洛川黄土沉积物中稀土元素及其它微量元素的化学淋滤研究

本文采用化学淋滤的方法对洛川黄土沉积物的酸溶和酸不溶相中稀土元素以及其它微量元素的分布分配特征进行了系统的分析。     

Behaviours of REE and Other Trace Elements During Pedological Weathering-Evidence from Chemical Leaching of Loess and Palaeosol from the Luochuan Section in Central China

The chemical leaching method is used for a systematic analysis of distribution characteristics of acid-soluble and acid-insoluble REE and other trace elements from the Luochuan loess deposits. The study shows that the acid-insoluble phase in loess and palaeosol is a stable component of old aeolian dusts and is characteristic of the provenance; the acid-soluble phase is the unstable component in the weathering pedogenic process and reflects rock-forming features after accumulation of aeolian dusts. The acid-insoluble REE and acid-soluble Sr and Pb can be used as geochemical indicators respectively to trace the provenance characteristics and the weathering pedogenic process.     

镍钼在黑色岩系中富集成因的实验研究

对湘西和黔北早寒武世含Ｎｉ、Ｍｏ等多金属黑色岩系进行了淋滤实验。实验分别模拟了普通雨水、富ＣＯ２气雨水及酸性雨水三种不同淋滤条件。实验表明，黑色岩系中Ｍｏ、Ｎｉ、Ｖ等元素是比较容易被淋滤出的，尤其是在酸性雨水条件下，它们的带出强度最大。本实验为镍钼富集层的成因及寻找类似的矿床提供了依据。＊据（１９６２）。图３实验样品在不同雨水淋滤条件下各个元素带出强度的比较Ｆｉｇ．３Ｃｏｍｐａｒｉｓｏｎｏｆｔｈｅｉｎｔｅｎｓｉｔｙｏｆｔｈａｔｔｈｅｖａｒｉｏｕｓｅｌｅｍｅｎｔｉｎｓａｍｐｌｅｓｉｓｌｅａｃｋｅｄｏｕｔｂｙｄｉｆｆｅｒｅｎｔｒａｉｎｗａｔｅｒｓ从图３上可以看出，不同元素的带出强度有着明显的差别。例如带出强度最大的钼与其最小的铝可以相差４～５个数量级。现代空气雨水与饱含ＣＯ２气的雨水对样品淋滤强度的图形基本相似，也就是它们对各种元素的带出强度是相似的。而酸性度很大的雨水则明显地增强了多数元素的带出强度。值得注意的是钼在上述实验的任何条件下都能被强烈的带出，这是因为在表生条件的氧化作用下，Ｍｏ４＋可氧化为Ｍｏ６＋，形成溶解度较高的钼酸或钼酸盐，在溶液中搬运或呈胶体形式迁移，而在还原条件下，在有机质及铁硫化物大量存?     

低温条件下有机酸对铁、铜的淋滤实验研究

水／岩作用实验研究表明，在低温条件下柠檬酸、草酸和酒石酸对岩石中的铁、铜都有很高的淋滤率。这表明，在表生地质作用过程中有机酸对成矿元素有很强的活化能力。实验研究同时发现，有机酸对成矿元素的活化能力受其分解温度的限制，由于大部分有机酸的分解温度都在２５０℃以下，因而有机酸对成矿元素的活化仅限于低温条件。本次研究还显示，判断一种岩石能否成为矿源层，不能简单的以其中成矿元素的含量高低作为标准，其中更关键的因素是元素在岩石中的存在形式，如果成矿元素在岩石中难以活化的形式存在，那么含量再高也无法提供成矿物质     

512铀矿床地浸条件及技术经济评价

本文应用铀矿普查及地浸试验中获取的资料，对５１２矿床地质构造、矿石物质成份、矿床水文地质、工程地质及自然经济地理等地浸条件及矿床技术经济条件进行了分析评价，认为５１２矿床地浸条件较好，地浸技术指标适中，用酸法地浸开采具有耗酸量少、成本低、经济效益好的特点。在今后的开采中，若能解决伴生元素Ｒｅ，Ｓｅ，Ｍｏ的综合利用问题，将会大大提高矿床的经济价值。     

砂岩型铀矿地浸过程中的溶质迁移机理

讨论了“溶质迁移、溶质迁移面和特征性溶质迁移面”的概念，以及研究溶质迁移的方法和实例。在对381砂岩型铀矿床进行地浸模拟试验的基础上，应用以上概念和方法，对地浸过程中的溶质迁移过程进行了讨论，探讨了地浸过程的机理和发生的水文地球化学作用，总结了溶浸试验过程中的溶质迁移分带。在以上溶质迁移机理研究的基础上．论证了地浸地质工艺参数。地浸过程中分带的研究清楚地显示了浸铀的发展过程及其在各个时期各个地段铀浸出作用的进展程度。     

Oxidation of As-bearing gold ore—a comparison of batch and column experiments

This study deals with the experimental determination of the rate of weathering and As release from Au-bearing sulfide ores of the Mokrsko-West deposit (Czech Republic). The elevated As contents in the ore and the possible As mobilisation must be taken into account due to the close proximity of the deposit to the Vltava River, a source of drinking water for Prague. Crushed and homogenized ore material was divided into four grain-size fractions showing uniform chemical and mineralogical composition and subjected to batch and column leaching experiments. The most important reactions controlling metal leaching include (i) oxidation of sulfides, (ii) carbonate equilibrium and (iii) precipitation of hydrated ferric oxides (HFO). Hydrated ferric oxides were found to be important sorbents of mobilized As. The highest concentration of As in the leachates was obtained from the 64–1000 μm fraction. The oxidation rate in the agitated batch experiment calculated on the basis of sulfate concentrations is an order of magnitude higher (3.8×10⁻⁹ to 4.4×10⁻⁸ mol SO₄²⁻ h⁻¹ g⁻¹) than in the static column experiment (9.6×10⁻¹⁰ to 7.4×10⁻⁹ mol SO₄²⁻ h⁻¹ g⁻¹). The higher oxidation rate of batch experiments is explained by abrasion of oxidation products (mainly HFO) and by further exposition of reaction surfaces of the sulfide grains.     

Temperature and pH Dependence of Some Metals Leaching from Fly Ash of Municipal Solid Waste

Abstract. Municipal solid waste combustion leads to concentration of various metals in the solid residue (fly ash) remaining after combustion. These metals pose serious environmental hazard and require proper handling and monitoring in order to control their harmful effects. Leachability of some metals from fly ash was examined in fly ash and Milli-Q water mixture (liquid-to-solid ratio, 100) under various temperature and pH conditions in the laboratory. The leaching experiments conducted for 24 hours showed that pH was generally more important than temperature in controlling the amount of metals leached out of the fly ash. However, at a given pH, rise in temperature led to different degree of (usually one to two fold) enhanced or reduced leaching of metals. Owing to amphoteric nature of oxides of Al, Cr, Pb and Zn, these metals often yielded typical pattern of increase and decrease in their concentrations with change in pH. The extent of leaching of Cr and Pb in our experiments suggests that decrease of pH to acidic range in the case of Pb and to neutral to acidic range for Cr over a long period of storage of fly ash at solid waste dumping site may facilitate leaching of these metals from fly ash, leading to contamination of groundwater to the level that exceeds beyond the level permitted by the environmental laws.