甘肃省阳山金矿田金的赋存状态和金矿物特征

甘肃阳山金矿田属于类卡林型金矿床,金矿化类型主要有蚀变千枚岩、蚀变斜长花岗斑岩、蚀变砂岩、蚀变灰岩四种。金多呈独立金矿物形式出现,少许呈分散状,矿石中金矿物以自然金为主,其次是银金矿。金矿物以包体金、裂隙金、粒间金等形式嵌布于毒砂、黄铁矿、辉锑矿、粘土矿物等主要载金矿物中,且毒砂、黄铁矿、辉锑矿较其它金属硫化物中占优势。金矿物形态各样,粒度以微细粒为主。金矿物特征反映出本区金矿床的成矿物质主要来源于变质岩、岩浆岩和地幔,成矿作用与印支晚期中酸性侵入岩有关。这与地质地球化学研究所获得的矿床成因认识相一致。     

南美洲大型-超大型金矿地质特征与成矿作用研究

金是南美洲仅次于铜的优势矿种,据美国地质调查局统计,2016年秘鲁金矿储量2800 t,巴西金矿储量2400 t,智利仅公布到2014年金矿储量3900 t。通过对南美安第斯成矿带和南美地台金矿地质背景分析,根据对31个大型-超大型金矿的综合研究,剖析斑岩型、浅成低温热液型、IOCG型、造山型等不同类型金矿床的时空分布、地质特征,梳理重要成矿区特征,摸清区域构造岩浆-成矿作用演化的关系,为以后在南美洲金矿的勘查开发提供科学依据。在安第斯成矿带,金成矿作用与太平洋板块向南美大陆板块的俯冲密切相关,大型-超大型金矿类型主要是以浅成低温热液型,以及与铜共生的斑岩型、IOCG型矿床为主,大规模金成矿作用集中在新生代,形成了众多世界著名的金矿床。南美地台成矿带位于亚马孙陆块边缘,受古元古代(2.5~1.8 Ga)Trans-Amazonian旋回影响,经历了反复俯冲造山运动,大型-超大型金矿以造山带型金矿为主,主要成矿期在太古宙—新元古代。南美的金资源相当丰富,未来具有巨大的勘查开发潜力。     

中国东北寒区的风化壳与砂金矿床

大、小兴安岭北部寒区发育有3个砂金富集区.大量的找矿实践表明, 区内砂金矿床与内生成矿作用没有必然的联系, 砂金矿床与区域发育的风化壳有着密切的空间关系, 风化壳中的低温地球化学作用对区域砂金矿床的形成具有一定的控制作用.在砂金的形成过程中寒冻气候条件至关重要, 寒冷的气候条件有利于风化壳的保存, 同时, 冰冻条件下的水文地质条件及电化学作用也有利于金在其中的活化、迁移、富集和生长.     

中国火山岩地区金的成矿环境及分布规律

中国是一个火山岩广泛分布的国家，火山岩区的金矿不论其数量和储量在全国均占有重要地位，根据金和火山活动的关系，可划分出６种金矿类型，它们主要分布在６个火山岩区中，不同地区金的成矿作用各有其特色，总体可概括出７条成矿特征，这对于在我国广阔的火山岩区寻找金矿具有重要的指导意义。     

Mineralogical characteristics and recovery process optimization analysis of a refractory gold ore with gold particles mainly encapsulated in pyrite and Arsenopyrite

To interpret the leaching rules, select suitable treatment methods, or optimize the treatment process of refractory gold ores, an in-depth analysis of ore characteristics using ore mineralogy is required. In this study, the mineralogical characteristics of a low-grade refractory gold ore were analyzed by a variety of analytical techniques and methods. The ore composition was obtained by chemical analysis, and the main minerals include gold, pyrite, arsenopyrite, feldspar, mica, and quartz. Gold exists in the form of sub-microscopic gold with a particle size of fewer than 1.7 μm, of which 56.90 % is encapsulated gold, 16.97 % is semi-coated gold, and 26.13 % is fractured gold. The content, classification, shape, grain distribution, and occurrence state of the main minerals in the gold ore were obtained by microscopic observation and statistical analysis. Based on the results, the leaching rules of the gold ore were predicted, and suggestions for optimizing the pretreatment process were put forward. These results can accurately guide the pretreatment and leaching process of the gold ore and lay a foundation for the effective utilization of comparable gold ores.     

Selective extraction of organically bound gold in soils, lake sediments and stream sediments

The extraction of organically bound gold from surficial materials is accomplished by using a solution of 5% sodium hypochlorite. A 10-g sample is digested at least twice with 50 mL of hypochlorite solution. The recovery of gold from the organic phase is nearly quantitative for lake sediments and stream sediments high in organic content. For stream sediments and soils low in organics, the recovery of gold is complicated by the sorption of released gold onto inorganic sample components. For these materials, recoveries as low as 70% of the organically bound gold are possible. For a stream sediment sample containing 53.4 ppb gold, the precision of the method is approximately 6% for a 10-g sample and 14% when a 5-g sample of stream sediment is used. The results obtained for all materials tested indicate that a substantial fraction of the gold found in sediments and soils exists as organically bound gold.     

铜石杂岩体隐爆作用与金矿成矿的关系及其研究意义

山东省平邑县铜石地区是鲁西最重要的金矿产地,继归来庄大型金矿床发现之后,又相继发现了卓家庄特富金矿床及磨坊沟、梨方沟、贺山庄等具层控特征的金矿床,构成了铜石金矿田。这些金矿床的形成与铜石地区中生代多期次岩浆活动或隐爆作用密切相关,分布于岩体边部的隐爆-侵入角砾岩是金矿床的载体,成为寻找隐爆-侵入角砾岩型金矿的重要标志。     

阳山金矿带金的赋存状态及其对成矿过程的指示意义

阳山金矿带是西秦岭金矿带已探明金储量最大的独立金矿区,其矿化样式主要为微细浸染状矿化,其次为石英脉型矿化,可见金与“不可见金”均有发育,该金矿带是研究造山型金矿金赋存状态的理想地区,其研究成果对理解金成矿作用和过程以及指导选矿工艺具有重要意义。论文在翔实的野外地质调查和显微观察基础上,将成矿期划分为早阶段(黄铁矿石英)、主阶段(黄铁矿毒砂绢云母石英)和晚阶段(辉锑矿石英方解石),综合应用电子探针、激光剥蚀电感耦合等离子体质谱、电感耦合等离子质谱仪、高分辨率透射电镜、X射线粉晶衍射等技术,剖析阳山金矿带不同成矿阶段金的赋存状态,进而探讨其对成矿过程的指示意义。研究表明：成矿早、主阶段以微细浸染状硫化物矿化为主,金主要以晶格金的形式赋存于黄铁矿和毒砂中;而成矿晚阶段以脉状矿化为主,金主要以自然金的形式存在。金的赋存状态的变化,指示从成矿早阶段到晚阶段,成矿温度、压力逐渐降低,成矿流体成分由富As流体演化为相对贫As且富Sb的流体。     

贵州省金矿资源分布特征及开发利用布局建议

贵州省金矿资源丰富且分布广泛,包括岩金、砂金和伴生金三类,主要以岩金为主,砂金和伴生金较少。按矿床类型划分,岩金分为卡林型金矿、石英脉型金矿和红土型金矿。文章介绍了贵州省金矿资源分布特征、金矿资源勘查开发利用现状和不同矿床类型金矿资源分布特征。根据贵州省金矿资源分布相对集中的特点,划分出册亨—兴仁金矿矿集区、锦屏—天柱金矿矿集区,并提出了贵州省金矿开发利用布局建议和政策建议。     

地质冶金学及其在金和关键金属赋存状态研究中的新应用

地质冶金学(Geometallurgy)是一门交叉学科,将矿体的地质学、地球化学和矿物学特征与冶金性能联系起来,目标是描述和了解矿体的冶金性质的多样性,并建立三维地质冶金学模型,用于协助矿山开采计划和优化工艺设计流程等。金矿石依据选冶难度可以分为易选矿石和难选矿石,其中难选矿石的原因主要可以归结为金的包裹和脉石矿物影响两种因素。金的地质冶金学需要查清金的赋存状态,包括金矿物的种类与矿石难选冶的原因,从而为选矿提供指导。金的赋存形态包括显微金、亚显微金和表面金,研究金的赋存状态需要使用自动矿物分析系统等分析显微金矿物,并结合多种选矿试验来交叉验证,加上对载金矿物中亚显微金的分析,得到金的全部分布特征。不同成因类型的金矿床往往具有不同的地质冶金学特征,同时金的地质冶金学研究还可以对矿床的成因和演化过程提供依据。本文简要介绍了近年来典型的热液金矿床包括斑岩型、浅成低温热液型、铁氧化物-铜-金(IOCG)型、卡林型和矽卡岩型的地质冶金学的研究进展,以及应用于地质冶金学上的新方法如VNIR-SWIR高光谱技术、地球化学数据机器学习。关键金属具有含量低、矿物细小的研究难点,与金的地质冶金学研究具有诸多相似之处,因此本文提出将金的赋存状态研究的流程和新技术方法应用于关键金属矿床,并设计了关键金属赋存状态的研究流程和规范化表达,进一步延伸了地质冶金学的内涵和外延。     

Simulating Experiments on Enrichment of Gold by Bacteria and Their Geochemical Significance

The experiments on the enrichment of gold by bacteria indicate that bacteria have a very intense capacity of enriching gold and act as an arrester of trace gold in sea water,Bacteria enrich gold in two forms:absorption and adsorption.Absorption means that gold finds its way into organisms and it is combined with the mercapto group of protein,whereas adsorption means that gold is adsorbed on organisma by amino acid secreted by cell walls,Bacteria are organisms with very high vitality and reproductive capacity and huge productivity in nature Bacteria,which are important geolgical agents for gold enrichment and can exert effects on geological environments by their metabolism,are of important geochemical significance for the formation of gold-bearing black rock series.     

Mossman orogenic gold province in north Queensland,Australia: regional metallogenic controls and undiscovered gold endowment

The Hodgkinson and Broken River provinces of the Mossman Orogen in north Queensland host numerous orogenic gold deposits and still remain under-explored. This paper discusses regional metallogenic controls and results of a probabilistic quantitative assessment of undiscovered gold potential in the region. Significant orogenic gold deposits in the region occur only within relatively small well-endowed metallogenic zones, likely to be controlled by the eastern margin of the Paleoproterozoic continental crust underlying the western Mossman Orogen. Three distinct styles of primary orogenic gold deposits are present in the area: gold–quartz veins, refractory gold associated with quartz–pyrite–arsenopyrite veins and stockworks and stibnite–quartz±gold veins. Refractory gold deposits are estimated to have the highest potential for significant undiscovered resources in the region. The Hodgkinson Province is estimated to host between one and ten significant undiscovered refractory gold ore fields, with a 50 % probability of at least 20 t of total contained gold and a 90 % probability of at least 1 t. The Broken River Province is estimated to host up to five significant undiscovered refractory gold ore fields, with a 50 % probability of at least 12 t of contained gold.     

全球金矿床类型划分

基于矿床"棋盘式"分类方法,对金矿床类型进行了划分。"棋盘式"矿床分类是指,将金矿床分为岩浆型金矿床、与构造有关的金矿床、沉积型金矿床及变质型金矿床四大类,每大类又可分为若干小类。通过该方法在金矿床分类中的应用及相关典型金矿床的介绍,弥补和补充原有分类方案的不足,完善对金矿床的认识,为找矿和勘探提供帮助。     

甘肃省徽县头滩子金矿地质特征及远景预测

徽县头滩子金矿是近年来在西秦岭东部地区发现的规模较大的新类型金矿床。文章通过对区域成矿地质背景的分析研究,结合头滩子金矿的地质特征,总结了该区金矿的控矿因素,初步认为,泥盆系和石炭系含碳细碎屑岩和碳酸盐岩建造含金背景值较高,为金成矿矿源之一;印支期及燕山期花岗斑岩、正长斑岩及脉岩为金成矿提供热源和深部矿源;东西向、北东向、北西向三组断裂交汇显示出环形构造特征,构成聚矿场。以金矿为中心,向外扩散以后出现锑矿和汞矿,属低温成矿系列。该矿床在西秦岭东部南缘具有代表性,据初步预测,该矿区有一处大型金矿产地,在矿区外围有3个找矿靶区。     

The geochemistry of Witwatersrand-type gold deposits and the possible influence of ancient prokaryotic communities on gold dissolution and precipitation

Compared to the prokaryote-dominated lower Proterozoic there are few environments now left on Earth where prokaryotes are dominant. By about 2.5 Ga chemical conditions affecting the solution and precipitation of minerals were much influenced by microbial communities. Results of recent experiments show that modern living prokaryotes are capable of actively precipitating or flocculating gold. This process goes far towards explaining the phenomenal extent to which gold is enriched in kerogenous marker seams on the Witwatersrand.Neutron activation analyses confirm that gold is likewise anomalously enriched in kerogenous material present in the Lower Huronian metasediments of Ontario. Long known as thucholite, it appears from pyrolysis and X-ray studies of a sample from a stratiform occurrence that it is a kerogen remarkably similar to kerogen from the Vaal Reef, South Africa. A prokaryote precursor has been postulated for the Vaal Reef kerogen, and the same may well be true of at least some of the stratiform occurrences of kerogen in the Huronian.Simplifying solutions to the metallogeny of Witwatersrand-type gold that do not take into account the diverse types of gold in the deposits, are unrealistic. Precipitated gold associated with kerogen is only one of four main types of Witwatesrand gold, but it may be the major one. Our proposed model to account for this gold involves the weathering of gold from Archean source rock under anaerobic conditions, and probably in the presence of S-cycling microbial communities. Transported as a solution or colloid the gold was stabilized by humic acids, or S-cycle intermediates, and was deposited onto braided alluvial plains. There, in the presence of extensive prokaryote microbial mats (now preserved as kerogen), gold was precipitated in forms characteristic of biologically induced biomineralization.     

黑龙江布鲁嘎里河砂金矿地质特征及成因探讨

布鲁嘎里河砂金矿产于兴华渡口群下兴华组和晋宁期花岗岩分布区。研究区为低山丘陵,经长期风化剥蚀和堆积形成了一系列侵蚀堆积地貌。第四纪松散物覆盖在下兴华组地层和花岗岩之上。目前已圈定２条矿体。矿体连续性好,平面上呈条带状,多为粒状,板状,片状,ＮＥ,ＮＷ向断裂不但控制区内的地貌形态,也为砂金的形成提供了有利地质条件。砂金分布区应该是原生金矿（化）的集中区,在普勘勘探砂金的同时更要注意寻找原生金矿,在兴     

半干旱—干旱地区以钙积层为采样介质的隐伏金矿地球化学勘查

在隐伏金矿的地球化学勘查中,常用的采样介质包括岩石、水系沉积物、土壤、植物和地气等.近几十年,澳大利亚在半干旱—干旱地区以钙积层作为隐伏金矿床地球化学勘查的采样介质,并取得了成功.本文对以钙积层作为隐伏金矿地球化学勘查采样介质的理论和勘查进展进行总结,其勘查理论基础是土壤剖面中金-钙高度相关性,其成因机理较合理地解释为...     

北祁连西段牛毛泉东金矿地质特征、成矿时代及成因分析

牛毛泉东金矿位于北祁连造山带与阿尔金断裂的结合部位,该地区被誉为西北的"金三角"。牛毛泉东金矿为该地区近年来新发现的受脆韧性剪切带控制的金矿床,金矿体产于阴沟群安山质凝灰岩、安山质凝灰熔岩中的近东西向脆韧性剪切蚀变带,矿化受构造控制显著,成矿具有多阶段性,金主要形成于硫化物-石英-金矿化阶段。矿脉两侧热液蚀变强烈,与成矿有关的蚀变主要为硅化。通过石英流体包裹体测得金矿石中流体包裹体的均一温度112～191℃;成矿流体盐度0.35%～7.86%,平均4.77%;密度为0.92～0.96 g/cm^3,平均0.95 g/cm^3,显示成矿流体具有浅层低温热液特征。对黄铁绢英岩型矿石中绢云母⁴⁰Ar-³⁹Ar测年获得坪年龄为(296.7±2.8) Ma,对应于北祁连陆内伸展拉张构造演化过程。矿床的地质特征及成矿时代与邻近的寒山金矿类似,并受同一条韧性脆性断裂构造带控制,均为低硫浅成低温热液型金矿,主成矿时代为华力西晚期。牛毛泉东金矿的发现及成因研究对指导区域找矿方向具有重要的意义。     

内蒙古虎拉林地区砂金与岩金的关系

虎拉林地区砂、岩金矿的空间位置关系十分密切。在虎拉林河上中下游及虎拉林岩金矿分别采取样品，结果表明虎拉林河砂金粒度大，分选较差，磨圆度差；砂金形态总体上以粒状为主；溶蚀系数均值小于1。微量元素含量特征表明砂金的主要物质来源是近源，与岩金矿关系密切且具有继承性。虎拉林岩金矿床的矿石中自然金颗粒粗大，矿体的上部遭到剥蚀，虎拉林河砂金主要来源于虎拉林岩金矿床，砂金可作为岩金的找矿标志。自然金化学-结晶温度图表明砂金的原生Au源为中低温热液矿床。     

茅排地区金水文地球化学特征及找矿效果

本文通过对临川茅排地区金水文地球化学调查，指出了该区金水文地球化学特征，总结了金水地球化学找矿标志，并对其找矿效果进行了评价。