新疆雪米斯坦火山岩带铀资源调查评价主要进展及成果

总结了铀资源调查评价工作的主要进展及成果,通过区域性成矿条件分析,认为新疆雪米斯坦火山岩带具备形成铀矿化的有利地质背景。按照控矿要素归纳了不同地段的铀矿化特征,白杨河铀多金属矿床受次火山岩接触带控制,伊尼萨拉—十月工区铀矿化集中区受次级裂隙带控制,马门特矿化点受塌陷式火山机构控制。结合地质条件及工作程度,预测了铀矿找矿远景区,指明了找矿方向,提出了下一步工作建议。     

对夹皮沟金矿集中区发现新的大型金矿床的思考

重新界定的夹皮沟金矿集中区包括了太古宙花岗-绿岩带和高级变质区两个组成部分。这-太古宙地体除受到新太古宙-早元古宙的金矿成矿作用外，还受到中生代构造岩浆活动的影响，使该区金矿具有多期成矿特点。有利构造部位上的地球化学异常是寻找金矿的切入点，经查证，在高级变质区内发现了大型构造蚀变岩型六批叶沟金矿。强调了在成矿集中区内找矿的重要性。     

Characterization of corrosion products in the permeable reactive barriers

 The impact of geochemical processes and microbial activity has been a major concern for the long-term performance of reactive iron barriers because corrosion products and precipitates during the water treatment with reactive materials will decrease the reactivity and permeability of the iron bed. This study characterizes corrosion products in reactive iron barrier as well as evaluates the effect of the iron corrosion products and precipitates on iron wall performance during contaminated-water treatment under varying conditions. Major phases in the reactive iron barrier include iron oxides, carbonates, iron sulfides, and elemental sulfur, depending on the degree of iron oxidation, groundwater chemistry, and microbial activity. Detailed geochemical and mineralogical characteristics are imperative for long-range predictions of the reactive iron wall performance on water treatment because the surface coating materials reduce the effectiveness of the zero-valent iron media. Received: 17 September 1999 · Accepted: 11 April 2000     

几个铀矿床碱交代作用中重砂矿物变化的研究

本文通过对碱交代作用前后岩石中重砂矿物──晶质铀矿、锆石、榍石和含铁氧化物等的研究,得出如下结论：在碱交代作用中,含铀副矿物由于在碱性热液中不稳定而大量减少,残留副矿物的铀含量也比交代前减少,其释放出的铀遂成为热液中的铀源之一;碱交代热液呈氧化性质,致使碱交代岩由于高价铁氧化物含量增高而普遍发生“红化”;一些硅酸盐矿物,如石榴石、角闪石、黑云母、榍石等也由于在碱性热液中不稳定而分解。     

浓酸熟化——一种有效的硬岩铀矿浸出方法

本文通过对某中生代火山岩型铀矿床矿石进行铀浸出试验研究,认为浓酸熟化浸出法是处理硬岩铀矿石、提高其铀浸出率的一种有效方法。本文所研究的铀矿石,在浸出条件相同的情况下,浓酸熟化法的铀浸出率比常规酸浸法高20％左右。     

512—1铀矿床矿化特征及其成因探讨

512-1铀矿床位于白依背斜北翼志留系下统中,含矿岩层为碳质泥质板岩所夹的硅灰岩透镜体。区内岩浆岩不发育。铀矿体受地层、岩性、东西向走向断层和北东向切层断裂破碎带控制,呈透镜状,以边幕式斜列产出。合矿岩石主要为破碎或碎裂的硅质灰岩、硅岩。铀赋存形式以吸附状态为主,有少量的沥青铀矿、铀黑和铀的次生矿物。铀通过同生富集,后生再造等多期地质作用富集成工业矿体。     

Heavy metal geochemistry of the acid mine drainage discharged from the Hejiacun uranium mine in central Hunan,China

The acid mine drainage (AMD) discharged from the Hejiacun uranium mine in central Hunan (China) was sampled and analyzed using ICP-MS techniques. The analyzing results show that the AMD is characterized by the major ions Fe_Total, Mn, Al and Si, and is concentrated with heavy metals and metalloids including Cd, Co, Ni, Zn, U, Cu, Pb, Tl, V, Cr, Se, As and Sb. During the AMD flowing downstream, the dissolved heavy metals were removed from the AMD waters through adsorption onto and co-precipitation with metal-oxhydroxides coated on the streambed. Among these metals, Cd, Co, Ni, Zn, U, Cu, Pb and Tl are negatively correlated to pH values, and positively correlated to major ions Fe, Al, Si, Mn, Mg, Ca and K. The metals/metalloids V, Cr, Se, As and Sb are conservative in the AMD solution, and negatively-correlated to major ions Na, Ca and Mg. Due to the above different behaviors of these chemical elements, the pH-negatively related metals (PM) and the conservative metals (CM) are identified; the PM metals include Cd, Co, Ni, Zn, U, Cu, Pb and Tl, and the CM metals V, Cr, Se, As and Sb. Based on understanding the geochemistry of PM and CM metals in the AMD waters, a new equation: EXT = (Acidity + PM)/pH + CM × pH, is proposed to estimate and evaluate extent of heavy-metal pollution (EXT) of AMD. The evaluation results show that the AMD and surface waters of the mine area have high EXT values, and they could be the potential source of heavy-metal contamination of the surrounding environment. Therefore, it is suggested that both the AMD and surface waters should be treated before they are drained out of the mine district, for which the traditional dilution and neutralization methods can be applied to remove the PM metals from the AMD waters, and new techniques through reducing the pH value of the downstream AMD waters should be developed for removal of the CM metals.     

二连盆地含矿建造后生改造作用过程及其演化

通过对二连盆地地质发展史、构造运动和沉积作用特征的分析，将盆地后生改造作用过程可划分为四个具有不同特点的基本演化阶段：晚白垩世阶段(K2)、古新世一始新世阶段(E1-2)、渐新世一中新世阶段(E3—N1)和上新世一第四纪阶段(N2-Q)。其中每一阶段依据古构造、古水文地质图及古气候特征，将盖层后生改造作用划分还原型和氧化型两种基本类型。对第一类型，划分出油气区、还原剂迁移方向和呈现还原后生改造作用的地区；对第二类型，划分出含氧含铀潜水运移方向和含氧含铀层间承压水运移方向。这对评价二连盆地的铀成矿远景具有现实意义。     

西北地区钙结岩(膏结岩)特征及铀成矿条件初析

从已获资料分析出我国西北地区含铀钙结岩(膏结岩)主要发育在古盐湖中。它是由膏结泥岩、膏结砾岩、膏结砂岩等组成。含铀层数多,工业矿化只在近地表一层或两层,含铀矿物主要是硅钙铀矿、钒钙铀矿、钒钾铀矿等。以西北区域地质特征及古气候条件为依据,结合区调、普查,勘探成果进行综合对比,编出了钙(膏)结岩分布略图,并认为钙(膏)结岩型铀矿化是西北地区值得探索的一种新类型。