共查询到20条相似文献,搜索用时 31 毫秒
1.
D. C. Harris 《Mineralium Deposita》1990,25(1):S3-S7
Processing of most gold ores, other than placers, involves conventional gravity separation and direct cyanidation. The difficult (or refractory) gold ores are not amenable to direct cyanidation and these ores require detailed mineralogical investigations to assist in determining the recovery processes. There are six mineralogical factors that can contribute to poorer recoveries. These are 1. the nature of the gold-containing minerals, 2. the grain size of the gold minerals, 3. the nature of the gangue minerals, 4. the associated sulfide minerals, 5. coatings on gold, and 6. chemically bound or invisible gold.Geological Survey of Canada Contribution Number 13089 相似文献
2.
3.
小秦岭金矿田构造演化与金矿成矿作用 总被引:1,自引:0,他引:1
依据小秦岭金矿田的地质构造穿插关系和同位素年龄资料,建立了本区构造、岩浆、成矿事件序列。在此基础上,将小秦岭地区的构造演化划分为6个阶段:褶皱变质、韧性剪切变形、稳定升降、韧-脆性断裂转化、断裂活动、抬升剥蚀阶段。对小秦岭金矿田的成矿时代,成矿深度、矿床成因等地质问题,给出了构造地质学方面的判据。 相似文献
4.
胶东地区探明金储量超过5000t,是我国最重要的金矿集区。玲珑金矿区位于胶东西北部招-平断裂北段,具有典型含金石英脉矿床的特征。矿区部分矿段产出富碲铋化物的明金矿石,是研究富碲铋化物金矿床成因和金超级富集机制的理想对象。通过显微岩相学观察、扫描电镜及电子探针分析,首次对胶东玲珑金矿区富碲铋化物明金矿石的矿物组合和形成机制进行了较为详细的研究。玲珑金矿区含明金矿石中的金矿物主要为含银自然金,成色整体较高,平均为894。共发现了五种与自然金共生的碲化物,分别是辉碲铋矿、碲铋矿、碲银矿、碲铋银矿和碲镍矿,其中辉碲铋矿含量最多。通过矿物共生组合研究及物理化学条件分析,确定成矿流体的碲逸度范围为-12.6相似文献
5.
Calculations based on the available thermodynamic data of AuCl
2
−
and Au (HS)
2
−
indicate that AuCl
2
−
is responsible for the transport and enrichment of gold during the stage of pre-concentration in the source bed while Au
(HS)
2
−
is the main gold species involved in the formation of gold deposits in response to hydrothermal reworking. Acid chloride
solutions witha
Cl
− > 10° and sulfur-rich solutions with aΣs in excess of 10−2 are held as important criteria for gold enrichment in the source bed and for the formation of gold deposits by subsequent
hydrothermal event, respectively. 相似文献
6.
独狼沟金矿是位于丹巴成矿带中穹窿边缘的典型的石英脉型金矿,矿床中发育大量明金与碲铋矿物。本文以独狼沟金矿中碲铋矿物及自然金为主要研究对象,通过显微岩相学观察、扫描电镜、能谱以及电子探针分析,对矿床中碲铋矿物和自然金的赋存状态进行了较为详细的研究,并对金的富集机制进行了探讨。结果表明,碲铋矿物与自然金主要在成矿Ⅱ、Ⅲ阶段产出,矿石中自然金主要为含银自然金,成色整体偏高,平均为881,碲铋矿物主要有楚碲铋矿、叶碲铋矿、赫碲铋矿、硫碲铋矿B、未命名碲铋矿物(Bi2Te、Bi8Te3、Bi3Te)以及自然铋,碲铋矿物与自然金具密切的时空关系。结合前人流体包裹体的研究结果,认为成矿Ⅱ阶段到Ⅲ阶段过渡的过程中温度以及体系中碲逸度的降低是矿床中多种碲铋矿物相形成的关键,独狼沟金矿成矿的物理化学条件以及碲铋矿物与自然金的矿物特征均指示成矿过程中金-铋-碲熔体对热液中金的抽取是导致自然金富集的关键。 相似文献
7.
T.M Seward 《Geochimica et cosmochimica acta》1973,37(3):379-399
The solubility of gold in aqueous sulphide solutions has been determined from pH20°C ≈ 4 to pH20°C ≈ 9.5 in the presence of a pyrite-pyrrhotite redox buffer at temperatures from 160 to 300°C and 1000 bar pressure. Maximum solubilities were obtained in the neutral region of pH as, for example, with mNaHS = 0.15 m, pH20°C = 5.96, T = 309°C, P = 1000 bar where a gold solubility of 225 mg/kg was obtained. It was concluded that three thio gold complexes contributed to the solubility. The complex Au2(HS)2S2? predominated in alkaline solution, the Au(HS)2? complex occurred in the neutral pH region, and in the acid pH region, it was concluded with less certainty that the Au(HS)° complex was present. Formation constants calculated forAu2(HS)2S2? and Au (HS)2? emphasize their high stability. In the temperature range from 175 to 250°C, values of pβ for Au2(HS)2S2? vary from ?53.0 to 47.9 (±1.6) and from ?23.1 to ?19.5 ( ± 1.5) for Au(HS)2?. Equilibrium constante for the dissolution reactions, and 2Au° + H2S + 2H8? ? Au(HS)2? + H2 vary from pKm = +2.4 to +2.55 (±0.10) for Au2(HS)2S2? and from pKn = + 1.29 to + 1.19 (±0.10) for Au(HS)2? over the temperature range 175 to 250°C. Enthalpies of these dissolution reactions were calculated to be ΔHm° = ?5.2 ±2.0 kcal/mol and ΔHn° = +1.7 ±2.0 kcal/mol respectively. It was concluded that gold is probably transported in hydrothermal ore solutions as both thio and chloro complexes and may be deposited in response to changes in temperature, pressure, pH, oxidation potential of the system and total sulphur concentration. 相似文献
8.
9.
从含铜铅金精矿中提取金银的工艺方法 总被引:1,自引:0,他引:1
采用湿法预处理除铜 -氨氰法研究了从含 Cu、Pb金精矿中提取 Au、Ag的新工艺方法。它与常规方法相比 ,Au、Ag的回收率分别提高了 34 .78%和 1 2 .52 % ,对于中小型黄金矿山具有推广价值。 相似文献
10.
11.
胶东地区破碎带蚀变岩型金矿时代的测定及其地质意义 总被引:30,自引:4,他引:26
通过对胶东半岛西北部超大型破碎带蚀变岩型金矿 -新城金矿的强烈热液交代成因黄铁绢英岩 Rb- Sr等时线法测年 ,获得 116 .6± 5 .3Ma成矿年龄。结合本区焦家、仓上等大型 -超大型金矿蚀变矿物、石英流体包裹体的 Rb- Sr等时线年龄、K- Ar年龄 (10 5± 7Ma;10 6± 2 Ma;113.5± 0 .6 Ma)等前人成果 ,确定胶东半岛西北部破碎带蚀变岩型金矿成矿时代主要集中在 10 0~ 117Ma。与围岩花岗岩、花岗闪长岩的成岩年龄 (16 0~ 15 0 Ma;130~ 12 6 Ma)存在着近 10 Ma的时差 ,并根据(87Sr/ 86 Sr) i比值以及已有的 C、H、O稳定同位素资料表明 ,即使成矿物质部分来源于围岩花岗岩类 ,但成矿作用与岩浆活动无明显的成因关系 ,而是深部循环的大气降水或幔源 C- H - O流体参与成矿作用的结果 相似文献
12.
陕西小秦岭金矿床中金的赋存状态及分布规律 总被引:2,自引:0,他引:2
陕西小秦岭脉状金矿床中,金的赋存状态及其分布与硫化物的发育程度密切相关,金优先赋存于硫化矿物中,只有当硫化物不发育时,才主要以金矿物形式赋存于石英等矿物中。金矿物的Ag/Au比率主要受成矿温度、硫化物发育程度、成矿热液中Cl/S浓度比值等因素制约。 相似文献
13.
Determining the source of sulfur in an ore deposit is key to understanding the nature of the ore forming processes. The Neoarchaean Paulsens sediment-hosted gold deposit (∼1 Moz @ 7.6 g/t) located in the Pilbara Craton of Western Australia exhibits many of the characteristics of Phanerozoic shale hosted gold deposits (e.g. Huijiabao Trend, Northern Carlin Trend and Sukhoi Log), in that 1) black shales are the dominant host rock, 2) gold is hosted in pyrite as both free gold and dissolved gold in the lattice of the pyrite, and 3) multiple generations of pyrite have formed due to a variety of geological processes. In this contribution we utilised Secondary Ion Mass Spectrometer (SIMS) to measure the in-situ quadrupole (32S, 33S, 34S and 36S) sulfur isotope compositions of the different generations of pyrite. Our results indicate that the both diagenetic and hydrothermal pyrite generations display similar and anomalous Δ33S signatures (up to +0.4‰). Further, the Δ33S-Δ36S arrays in the hydrothermal pyrite generations lie on a slope which is similar to that of the diagenetic pyrite. These data support the hypothesis that the sulfur in the ore zones came from the host Hardey Formation black shales.We also performed trace element analyses of syn-sedimentary and early diagenetic pyrite from the Hardey Formaiton using Nano Secondary Ion Mass Spectrometry (NanoSIMS), Electron Probe Microanalysis (EPMA) and Laser Ablation-inductively coupled plasma-mass spectrometry (LA-ICPMS), all of which show that the syn-sedimentary and early diagenetic pyrite contain high concentrations of many trace elements (As, Ni, Co, Cu, Ag, Se, Te, Bi), including up to 1.5 ppm Au. These metals contents are also abundant in the several generations of mineralised hydrothermal pyrite and form clear patterns of growth associated with couple dissolution reprecipitation reactions. These findings clearly indicate that the fluid that transported the Au must have also been enriched in the base and precious metals that are contained in the early, syn-diagenesis pyrite.Data from this study clearly support the hypothesis that in some sediment-hosted gold systems, all the sulfur and gold required to form the deposit are sourced from the local sedimentary package. By using the presence of anomalous mass independent sulfur isotope signatures as chemically conservative and indelible tracers, it is possible to fingerprint the source of sulfur in a wide range of mineral systems, thus enhancing predictive exploration strategies at the regional to camp scales. 相似文献
14.
胶东是我国最重要的黄金产地,也是全球成矿晚于赋矿围岩近2Ga的巨型金矿集区之一。大尹格庄金矿床位于胶西北招平断裂中段是区域内典型的超大型蚀变岩型金矿床也是胶东金矿集区内最大的金银伴生矿床。本研究在详实的野外地质调查和岩相学观察基础上对不同成矿阶段的石英中流体包裹体进行碳、氢、氧同位素测试和计算。大尹格庄金矿床热液成矿过程可分为四个阶段:黄铁矿-绢云母-石英阶段(Ⅰ阶段)、石英-黄铁矿阶段(Ⅰ阶段)、石英-多金属硫化物阶段(Ⅲ阶段)和石英-方解石-黄铁矿阶段(Ⅳ)。氢-氧同位素组成表明,Ⅰ阶段流体的δD为-84.4‰~-68.4‰,δ~(18)O为2.04‰~7.36‰;Ⅱ阶段流体的δD为-78.6‰~-69.8‰,δ~(18)O为0.3‰~4.2‰;Ⅲ阶段流体的δD为-81.4‰~-72.0‰,δ~(18)O为-3.47‰~-1.25‰。随着成矿作用进行,δ~(18)O逐渐降低。流体包裹体的碳-氧同位素分析表明,δ~(13)C和δ~(18)O分别随成矿作用的进行降低和升高。两种测试获得的氧同位素变化趋势不同,可能是由于前者是通过石英单矿物氧同位素计算得到的流体包裹体中水的氧同位素而后者测定的是流体包裹体中CO_2的氧同位素。综合分析表明,大尹格庄金矿床成矿流体主体为变质水;成矿作用过程中,断裂带强烈构造变形诱发次生包裹体的形成导致氢氧同位素组成向中生代大气水漂移。 相似文献
15.
16.
全鑫金矿为变质碎屑岩型金矿,矿石的化学成分较简单,主要为SiO2(73.60%)和A l2O3(10.40%),有用元素主要为Au(平均3.45×10-6),其次为Ag,有害元素主要是C有机,As,S,含量很低。主要金属矿物为褐铁矿、赤铁矿及黄钾铁钒;脉石矿物以石英、长石、绢云母及粘土矿物为主。矿石为自形-半自形粒状结构、浸染状构造。矿石中金大多为自然金,粒度一般<0.005 mm,主要以微细粒包裹金的形式存在,部分为裂隙金,金的载体矿物主要为褐铁矿、黄铁矿。 相似文献
17.
19.
西藏尼玛砂金矿中金和银的提纯与精炼 总被引:1,自引:0,他引:1
为提纯与精炼西藏尼玛砂金矿中的金和银,在王水介质中制作供还原的Au液,选择草酸作为还原剂很容易将Au还原,而且不与其他金属离子反应。砂金的提纯与精炼要经还原Au液、排除HNO3和砂金的2次溶解及Au的还原。尾渣以NaCO3、硼砂、KNO3为配料在焦炭炉中进行熔炼和泼珠,进而分离出金、银。在提取银的操作中,采用饱和NaCl水溶液。制定的金、银王水法提纯与精炼流程所产出金锭的成色大于等于99.99%,银锭成色大于等于99.90%。 相似文献