Sample records for gold ores

  1. Genesis of Gold- Silver Deposits in Qingchengzi Ore Field

    Wei Min


    The gold - silver complex ore field of Qingchengzi is located in Liaohe group of Liaodong rift. The gold - silver ore bodies mainly lie in Dashiqiao group and Gaixian group, which provides ore - forming materials for the mineralization. For taking place multi - period and multi - stage magmatic activities, the ore - forming materials in the formation had had dynamothermal metamorphism for a long time and enriched and formed ore bodies after magmatism in Indo- Chinese and Yanshan epoch. The ore bodies are controlled by stratigraphic formation and stored in the interformational faults and schistosity belts. Silicalite is the most important indicator for searching them. Although the Pb - Zn and the gold - silver deposits are the same series of mineralized products, their positions are different, resulting from the differences of elements nature and mineralized conditions. The gold silver deposits belong to strata - bound and hysterogenetic mesothermal - epithermal deposit.

  2. Beneficiation of the gold bearing ore by gravity and flotation

    Gül, Alim; Kangal, Olgaç; Sirkeci, Ayhan A.; Önal, Güven


    Gold concentration usually consists of gravity separation, flotation, cyanidation, or the combination of these processes. The choice among these processes depends on the mineralogical characterization and gold content of the ore. Recently, the recovery of gold using gravity methods has gained attention because of low cost and environmentally friendly operations. In this study, gold pre-concentrates were produced by the stepwise gravity separation and flotation techniques. The Knelson concentrator and conventional flotation were employed for the recovery of gold. Gold bearing ore samples were taken from Gümüşhane Region, northern east part of Turkey. As a result of stepwise Knelson concentration experiments, a gold concentrate assaying around 620 g/t is produced with 41.4wt% recovery. On the other hand, a gold concentrate about 82 g/t is obtained with 89.9wt% recovery from a gold ore assaying 6 g/t Au by direct flotation.


    N. Y. Samsonov


    Full Text Available An economic projection is presented in the paper on the heap leaching technology for extracting a residual gold from the gold-ore dumps accumulated at the exploited or closed gold mines. A brief analysis is performed on the legal status of use this source of raw materials, availability and efficiency of the heap leaching method are reviewed, and the potential users of this method are assessed. An investment plan is created for involving anthropogenic dumps of gold-raw materials at one of the ore deposits in Siberia (heap complex of the North-Western flank of the Sovetskoye minefield, Krasnoyarsk region, North-Yenisey area.

  4. Ore fluid geochemistry of the Jinlongshan Carlin type gold ore belt in Shaanxi Province, China


    The Jinlongshan gold ore belt in southern Shaanxi Province contains a number of Carlin-type gold deposits in the Qinling collisional orogenic belt. Their fluid inclusions are of the Na+ - Cl- type. From the main metallogenic stage to later stages, the total quantity of anions and cations, temperature and deoxidation parameter (R) for fluid inclusions all gradu ally decreased, suggesting the gradual intensification of fluid oxidation, the reduction of met allogenic depth and the input of meteoric water and organic components. The deposits were formed during crustal uplifting and hence had similar tectonic settings to orogenic gold depos its. The CO2 contents and CO2/H2O values of the ore fluid increased from early to late sta ges, and the wall-rock alteration is represented by decarbonation, which is inconsistent with the characteristics of orogenic gold deposits. It is also discovered that Na + , K + ,SO42-, Cl-and the total amounts of anions and cations in the inclusions in quartz are higher than those in the coexisting calcite. The H, O and C isotope ratios indicate that the ore fluid was sourced from meteoric water and metamorphic devolatilisation of the sedimentary rocks that host the ores. The high background δ18O and δ13C values of wall rocks resulted in high δ18O and δ13 C values of ore fluid and also high δ 18 O and δ 13 C values of hydrothermal minerals such as quartz and carbonate. The carbon in ore fluid stemmed largely from the hosting strata. The δ 18O and δ13C values of Fe-calcite and the δD values of fluid inclusions are lower than those of calcite and quartz. In terms of the theory of coordination chemistry, all these differences can be ascribed to water-rock interaction in the same fluid system, instead, to the multi source of ore fluid.

  5. Effects of iron oxidizing bacteria in thiourea leaching of gold ores

    甲斐, 敬美; 山崎, 研市; 高橋, 武重; カイ, タカミ; ヤマサキ, ケンイチ; タカハシ, タケシゲ; KAI, Takami; YAMASAKI, Kenichi; Takahashi, Takeshige


    Bacterial leaching was combined with thiourea method for the gold leaching from ores. For gold bearing pyrites, biological pre-oxidation has been generally perfomed. In the present study, we carried out the biological treatment to the high silicate bearing ores by using the iron oxidizing bacteria, Thiobacillus ferrooxidans. The recovery of gold and silver was enhanced by the biological pretreatment, while the effects of the treatment was influenced by the types of gold ores. Since the biolog...

  6. Synergistic extraction of gold from the refractory gold ore via ultrasound and chlorination-oxidation.

    Fu, Likang; Zhang, Libo; Wang, Shixing; Cui, Wei; Peng, Jinhui


    A synergistic extraction method for gold from the refractory gold ores via ultrasound and chlorination-oxidation was developed. The effects of solid-liquid ratio, extraction time, ultrasound power, NaClO concentration and NaOH concentration on the extraction rate of gold from the refractory gold ore were investigated. The optimum conditions were as follows: NaClO concentration of 1.5mol/L, NaOH concentration of 1.5mol/L, solid-liquid ratio of 5, ultrasound power of 200W and ultrasound time of 2h. Under the optimal conditions, 68.55% of gold was extracted. However, only 45.8% of gold was extracted after 6h without the ultrasound-assisted extraction. XRD and SEM were used to analyze the influence of ultrasound on the mineral properties and strengthening mechanism. The results showed that the interface layer was peeled, new surface was exposed, reaction resistance was reduced, the liquid-solid reaction was promoted and reaction speed was greatly improved under ultrasound. According to the results of range and variance analysis, the optimum leaching experiment with orthogonal design was almost identical with the optimum experiment of single factor. Among them, the ultrasound power was the most significant factors affecting leaching rate of gold. Compared with other extraction method, the synergistic extraction process decomposed completely sulfide and improved significantly the extraction rate of gold. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Source of ore-forming material for the Huangtuliang gold deposit, Hebei Province and ore prospecting in the deep periphery

    NIU Shuyin; SUN Aiqun; WANG Baode; HAN Yuchou; WEI Minghui; ZHANG Hai; ZHANG Ge; SHI Ping; WANG Wenxing


    The Huangtuliang gold deposit is characterized by its wide and large ore belt, stable extension and closely spaced orebodies. Unfortunately, no orebody was found by deep drilling. As a result, ore prospecting in this region was once put into dilemma. Detailed analysis of ore-forming and ore-controlling structures in the mining district by the authors has revealed that the ore-forming and ore-controlling structure in this mining district is a steeply dipping (85°-110°/∠70°-85° N-NNE), spade-shaped ductile shear zone, and the ore-controlling structures are a series of nearly erected second-ordered faults which are developed in the upper part of the ductile shear zone, intersecting with the ductile shear zone. Deep cutting of the ductile shear zone made it possible the ascending of ore fluids from the mantle plume at depth and these ore fluids would migrate upwards along the ductile shear zone under certain temperature and pressure conditions. Along their ascending path, the ore fluids would extract ore-forming elements from the country rocks and the extracted ore-forming elements would be deposited as ores in the hanging-wall second-ordered faults. The reason why no orebody was found in early prospecting at depth is that northward-dipping drilling in the southern part of the shear zone extended so deeply as to be beneath the shear zone. Only shallow-level orebodies could be found by southward-dipping drilling practice in the northern part of the shear zone.The location where deep-seated orebodies occurred shifted northwards and the orebodies occurred at greater depth.Therefore, it is natural that no orebody could be found when drill core passed through the shear zone. After the ore-forming and ore-controlling structures were well understood, the focus of ore prospecting was placed on the deep-level, northward-penetrating veins. In this way a number of new blind orebodies of great thickness have been found. On the basis of research development in the mining

  8. An Application of Microwave Pre-oxidation in Improving Gold Recovery of a Refractory Gold Ore


    Microwave radiation was employed as a pretreating technology to oxidise a refractory gold ore. Heating characteristics showed that, in an identical microwave field, the bulk temperature of the sample increased with microwave power, microwave radiation time and particle size. The rate of sulphur removal increased with microwave radiation time. Particle size also had a significant effect on the oxidation rate. Pyrite and marcasite could be oxidised into Fe2O3 with a high porous structure. When microwave radiation was carried out in a rotary bed, the oxidation was more uniformly developed, in comparison with in a fixed bed. Gold extraction by cyanidation could be remarkably improved after the ore was subjected to microwave radiation. The results showed that gold recovery could be improved from 37% to 69%~81.2%.

  9. The gold contained in imported lead ore concentrate is exempted from import value-added tax


    <正>According to the No. 14 proclamation issued by Customs Service, as from April 1st 2007, the importation of galena and the lead ore concentrate will enjoy the favorable policy intended for associated gold deposits, i.e. the value-added tax for gold component in the imported galena and lead ore concentrate is exempted,

  10. The applications of microwave energy to improve grindability and extraction of gold ores

    Huang, J H


    decomposed than pyrite at the same exposure conditions. Scanning electron microscope (SEM), optical microscope, and X-ray diffraction results indicated that the alterations during microwave treatment were complex. Some intermediate products (e.g. Fe sub ( sub 1 sub - sub x sub ) S) were formed before the sulphides were completely oxidised into hematite (Fe sub 2 O sub 3). Oxidation developed from the surfaces into the cores of the microwaved particles. Metallic particles were also formed during microwave exposure. Lihir gold ore, in which gold was finely disseminated in pyrite and marcasite, was an extremely refractory gold ore. Without pretreatment, only 37 approx 39% of the gold could be extracted with sodium cyanide. However, this was improved after the head ores or floatation concentrates were pretreated by microwave radiation. 74.5 approx 81.2% of the gold was extracted from the microwave treated head ore. The hydrometallurgical pretreatment of pyrite and marcasite in a microwave field and a conventional...

  11. Geological structure, composition of ores and age of the Bamsk gold deposit, Amur region, Russia

    Vitaly A. Stepanov


    The Bamsk gold-ore deposit is located in the Amur region, the Far East of Russia. It is confined to the Early Cretaceous volcanic-plutonic uplift of central type, located in the Stanov folded-clumpy Pre-Cambrian system. The deposit is presented by a series of gold-bearing quartz and carbonate-quartz vein-stringer zones. They are confined to the super-intrusive zone of the Nevachansk subvolcanic intrusion of sienite-porphyric composition. The mineralization is being controlled by zone of fractures developed in the autochthone ofthe Bamsk fault. Quartz, carbonates and sericite prevail in the composition of ores. The quantity of ore minerals doesn't exceed 1%~5%. Pyrite, chalcopyrite, galena and native gold are widely spread. Sheelite, gold and silver tellurides, sulphobismuthites, acanthite, sphalerite and cinnabar are less developed. Four stages of mineralization have been distinguished. Gold-sulphide-sulphosalt ore with tellurides of gold and silver is productive for gold. The following set of elements is typomorphic for the ores of the deposit: Au, Ag, Cu, Bi,Mo, Pb and Sb (W1, Pb1, Mo) -Cu- (Ag, Bi, Sb, Mn, W1, Pb2) form the vertical series of zoning. Rocks, enclosing the mineralization are exposed to the processes of listvenitization-beresitization. The processes of gumbeization and argillization are less manifested. The age of the gold mineralization, determined by Rb-Sr method on ore-accompanying minerals, is 130.6 Ma.

  12. Structure-geochemical zoning of Topolninsk gold-ore field (Gorny Altai)

    Timkin, T. V.; Lavrov, D. S.; Askanakova, O. Y.; Korotchenko, T. V.


    Geochemical zoning of prospective mineable gold-bearing skarns was carried out. The geochemical field abnormal structures of different hierarchy levels associated with gold- skarn formations were revealed. The interrelation between the structure of ore-geochemical fields and associated ring structures was studied. Complex structure-geochemical criteria for gold mineralization prospecting and evaluation were proposed.

  13. Characteristics and origin of ore-forming fluids of Jinchangqing gold (copper) ore deposit (s) in Xiangyun, Yunnan Province

    HE Mingqin; SONG Huanbin; LIU Jiajun; LI Chaoyang


    On the basis of results of the studies of primary fluid inclusions, and the hydrogen and oxygen isotope data, the authors concluded that the early-stage ore-forming fluid from the Jinchangqing gold (copper) ore deposit is a kind of sulfate type hot brine characterized by medium temperature and salinity, genetically related to the late-stage ore-forming fluid derived from an acidic and more reductive environment. However, the late-stage ore-forming fluid is a sort of low temperature and low salinity chloride-type hot brine which originated from a lower pressure, acidic and more oxidative environment. In general, the ore fluids were derived from the late-stage, or largely from the early-stage groundwater-derived meteoric water, which has a 12‰-17‰ heavier oxygen isotopic composition than the original rain water (δ 18 O= -15.3‰ ), and were formed during gold mineralization as a product of oxygen isotope exchange during the reaction between ore-forming fluid and wall rocks under a lower water/rock ratio condition.

  14. Deep-Source Ore-Forming Materials and Prospecting of Gold Deposits in Eastern Hebei, China

    王宝德; 牛树银; 孙爱群; 李红阳


    Eastern Hebei Province is one of the important gold mineralization areas in North China, and detailed investigations have been made in this area. Different mineralization models and different ore-forming sources have been proposed for the gold deposits in this area. As more detailed work was made and more information has been accumulated, it is necessary to make a new investigation on gold metallogenesis and its source. This paper presents the data about 13 gold deposits (occurrences). It is concluded that the element gold came from the deep mantle.Different models of metallogenesis substantially describe such processes that ore-forming fluids were involved in metallogenesis in different favorable loci. Gold ore prospecting should be focused on fluid channel ways and favorable structures.

  15. 76 FR 9449 - National Emission Standards for Hazardous Air Pollutants: Gold Mine Ore Processing and Production...


    ... add carbon adsorbers to control the ore pre-heaters. Based on this beyond-the-floor analysis, we... controls on all thermal units at Nevada gold mines. According to the commenters, these permits are...



    Adsorption capacity of ACFF in cyanide leaching liquor of gold ores was studied withcyanide leaching liquor of gold ores, containing various kinds of ions. The adsorbed leaching liquorwas analyzed by atomic emission spectroscopy and colorimetric method. The contents of variouskinds of ions in ACFF were determined with X-ray photoctron spectroscopy. ACFF not onlyadsorbed gold but also adsorbed arsenic, nickel, zinc, calcium, sulphur, bismuth, copper, iron. silverand cyanide anion. Atomic percentage of C and those of O, N, Zr, Fe increase and decreaserespectively with the increase of the layer depth, while those of Ca, Au, Ag keep constant.

  17. Ore-forming and Exploration Models of the Baguamiao Gold Deposit, Shaanxi Province


    The Baguamiao superlarge gold deposit in Shaanxi Province is one of the typical cases in China that are hosted by sedimentary rocks. Explorers and researchers have discussed the gold mineralization enrichment conditions by studying sulphur, oxygen, carbon, silicon stable isotopes and mineralizing fluid features of the Baguamiao gold deposit and proposed a hydrothermal sedimentation-magmatic reconstructing gold mineralization model featuring multi-sources of ore-forming materials and multistage mineralizations. In addition, prospecting for "Baguamiao-type"gold deposits was started in the Fengtai Basin and a great number of important prospecting targets such as Tonglinggou, Simaoling, Guoansi and Dachaigou were discovered.

  18. Isotope Geochemistry of Gold Ore Deposits in the Gezhen Shear Zone, Qiongxi, Hainan Island



    Gold deposits hosted in the Gezhen shear zone at Qingxi, Hainan Island occur in the Precambrian metamorphic rock series and are regionally developed in the N-E direction along the tectonic zone. From northeast to southwest are distributed the Tuwaishan-Baoban gold mining district, the Erjia gold mining district and the Bumo gold mining district, making up the most industrially important gold metallogenesis zone on the Hainan Island. Isotope geochemical studies of the typical gold deposits in this metallogenesis zone indicate that their ore-forming materials stemmed largely from the Baoban Group migmatite series, though the involvement of some plutonic materials could not be ruled out. The ore fluids are the mixture of migmatitized hydrothermal solutions and meteoric waters in addition to the involvement of local magmatic hydrothermal solutions. The superimposition of plutonic materials and magmatic hydrothermal solutions is controlled by the deformation environment of the shear zone and later magmatic activities. Obvious variations are noticed in isotopic composition in the region studied, probably related to tectonic deformation, metamorphism and other evolutionary characteristics. This study is of great significance in understanding the relationship between the shear zone and gold metallogenesis, the rules of gold metallogenesis and gold ore prognosis.

  19. New data on the age of gold mineralization of the Lugokan ore cluster (Eastern Transbaikalia)

    Redin, Yu. O.; Dultsev, V. F.; Nevolko, P. A.; Ponomarchuk, A. V.


    The Lugokan ore cluster is located in the southeastern part of Transbaikalia within the Aga-Borzya structural-formational zone of the Mongol-Okhotsk orogenic belt. The 40Ar/39Ar dating of K-bearing minerals of syngenetic to ore parageneses has been carried out applying stepwise heating technique: it has been demonstrated that the earliest gold-ore mineral associations are Au-pyrite-arsenopyrite (163 ±1.9 Ma) and Au-chalcopyrite (160 ±2 Ma). The later parageneses encompass the Au-polymetallic (156.3 ± 1.8 Ma) and Au-Bi (155.9 ± 4.5 Ma) one. By their ages and position in the general scheme of the Late Jurassic magmatism of Eastern Transbaikalia, the Lugokan's ore cluster gold-bearing mineral associations corresponds to the time of intrusion of the Shakhtama pluton (161 Ma) and the Porphyry Complex (159-155 Ma).

  20. Sulfate Saturated Hydrous Magmas Associated with Hydrothermal Gold Ores

    Chambefort, I.; Dilles, J. H.; Kent, A. J.


    -ICP-MS. Yanacocha anhydrite, hosted by amphiboles, are enriched in FeO (up to 0.6 wt%) and present positive anomalies in Eu and SrO (up to 8000ppm in anhydrite blebs hosted by high Al amphibole of the sample RC6). Anhydrite hosted by clinopyroxene (CPx) and low Al amphibole present higher Ce2O3 content (up to 2000ppm in CPx). In comparison, hydrothermal anhydrite analyzed from El Salvador, Butte and Ajo ore deposits contain less SrO (~ 2000 ppm) and no FeO. Pinatubo anhydrite phenocrysts and inclusions from the 1991 Pinatubo dacite yield low FeO contents, except anhydrite included in amphibole. These data suggest FeO in anhydrite is a product of subsolidus diffusion from the host. The breakdown of abundant anhydrite crystals "stored" in the magma may source of SO2-rich hydrothermal fluids that produced the sulfur enrichment (>500 M Tonnes) observed the Yanacocha hydrothermal gold deposits. The two populations of amphibole are evidence of magma mixing in the Yanacocha magmatic rocks. A sulfate-saturated oxidized dacitic magma chamber resided at about 4 to 8 km depth and 800°C was periodically underplated or fed by hydrous sulfate-rich oxidized basaltic-andesite magma. The shape of the irregular anhydrite blebs suggest that these inclusions could have been trapped as an immiscible sulfate- phosphate rich melt, despite the fact that anhydrite normally has a liquidus temperature of 1450°C and the host amphiboles crystallized at no more than 1050°C based on experiments on andesites and dacites.

  1. Shear Alteration, Mass Transfer and Gold Mineralization: An Example from Jiaodong Ore Deposit Concentrating Area, Shandong, China


    Taking the gold ore deposit concentrating area of Jiaodong area in Shandong, China for an example, based on geological analysis, and applying Gresens' equation, Grant's isocon diagram and O'hara microelement calculation method, a thorough study on shear alteration, mass transfer and gold mineralization was carried out. The authors also made mathematic simulation and geochemical analysis. The work reveals temporal-spatial changing regularities of temperature field and velocity field of fluids, and also reveals fluid transport-chemical reaction coupling metallogenic dynamics of the Jiaojia gold ore concentrating area. During shear-alteration process of the Jiaodong gold ore concentrating area, all kinds of components transferred with different amounts, fluid-rock ratio was rather high and volume strain was of dilation type. Fast flow of ore-forming fluid favors the occurrence of mixed fluid. Shear-fractured zones are places where there was strong transportationreaction coupling mineralization. Ore bodies were located in dilation space of shear structure where there was the greatest fluid flux. After the emplacement of the rock body, a convex heat field was formed around the rock body. It is one of the main metallogenic forces. The major reason for mineralization is the mobilization, migration and enrichment of ore-forming elements induced by shear compressive-extensional tectonism. Inclusion gold dominant Iow-grade ores were formed in the early ore-forming stage, while high-grade ores, which contained fissure gold and polymetallic veinlets, were formed in late ore-forming stage.

  2. Analysis of Ore-controlling Structure in the Qifengcha-Detiangou Gold Deposit, Huairou County, Beijing


    The Qifengcha-Detiangou gold deposit is a medium-sized deposit recently found in Huairou County, Beijing. It belongs to the altered mylonite type with superimposed quartz vein type and is related to the early Yanshanian magmatic activity. Characterized by multiperiodic activity, the NE-trending Qifengcha fault is a regional ore-controlling structure in the area, and gold mineralization develops only in its southeastern part. Meanwhile, gold mineralization is controlled by the Yunmengshan metamorphic core complex. The nearly N-S- and E-W-trending low-angle detachment faults, reformed by the Qifengcha fault in the northwestern part of the core complex, are the main ore-bearing faults. All discovered gold deposits are located within an area 1.5(4.0 km away from the boundary of the upwelling centre. The N-S- (NNE-) and E-W-trending ore-bearing faults are ductile-brittle structural zones developing in shallow positions and subjected mainly to compressive deformation. The structural ore-controlling effects are as follows. (1) The attitude, shape, and distribution of gold orebodies are controlled by faults. (2) There is a negative correlation between the gold abundance and the magnetic anisotropy (P) of the altered mylonite samples from the deposit, which shows that the gold mineralization is later than the structural deformation. (3) Quartz vein type mineralization is superimposed on altered mylonite type mineralization. (4) In mineralized mylonite, the stronger the ductile shear deformation, the easier the late-stage gold mineralization to occur and the higher the gold abundance. The richest gold mineralization occurs only around the centre of the fault subjected to the strongest deformation.

  3. Characterization of refractory behaviour of complex gold/silver ore by diagnostic leaching



    The amenability of a refractory ore to the extraction of gold and silver by cyanide leaching was investigated. Diagnostic leaching tests were also performed to shed light on the refractory characteristics of ore. The leaching tests show that the extraction of gold and silver is consistently low, i.e. ≤47% and ≤19.2%, respectively, over a leaching period of 24 h. Even fine grinding (e.g. <38 μm) does not improve the recovery of gold and silver. Diagnostic leaching approach provides information into the cause of the refractoriness of the ore. The findings suggest that the refractoriness is induced by the dissemination and encapsulation of the very fine gold and silver particles largely in the carbonates, oxides and sulfides and, to a small extent, with silicates present in the ore matrix. These findings highlight the practical importance of diagnostic leaching for the understanding of the refractory characteristic of such an ore and for the identification of possible pretreatment options to overcome its refractoriness prior to cyanide leaching.

  4. Deformation and metamorphism of gold-sulphide lodes in the Bhukia–Jagpura gold prospect, Rajasthan: Implications for ore genesis

    S Deol; A Chattopadhyay; M Deb


    The role of polyphase deformation in controlling the emplacement of gold-quartz lodes in dilational regimes is demonstrated from the Proterozoic Bhukia–Jagpura gold prospect in south Rajasthan. Earlier researchers deciphered the gold-sulphide mineralisation event as synchronous to the second phase of deformation (D2) without convincing microstructural or metamorphic evidences. In this contribution, we correlate the deformation and metamorphic imprints in the host rocks with those in the gold-sulphide mineralised zone, and present a new interpretation for the relative timing of gold emplacement vis-á-vis deformation. The ore-forming process first involved layer-parallel influx of ore-bearing hydrothermal fluids along S1 schistosity in the host rocks, synkinematic with respect to the first phase of deformation (D1). This initial ore concentration experienced metamorphism isofacially (∼500° C at 5.3 kb) along with its host rocks during D1, and subsequently underwent extensive remobilisation, giving rise to gold-bearing silicified lodes along the hinges and axial surfaces of F2 folds during D2.

  5. Geochemistry of ore-forming fluids and geological significance of the Kuoerzhenkuola gold field in Xinjiang, China

    SHEN Ping; SHEN Yuanchao; LIU Tiebing; LI Guangming; ZENG Qingdong


    The Kuoerzhenkuola gold field (including the Kuoerzhenkuola and the Buerkesidai gold deposits) is the most important one in the Sawuer gold belt, northern Xinjiang, China. Isotopic studies including D, O, He, C, S, Pb and Sr reveal that the ore-forming fluids of the Kuoerzhenkuola and the Buerkesidai deposits shared the same source: the water of ore fluids was magmatic water and minor meteoric water; the mineralizers and ore materials derived mainly from mantle beneath the island arc, and partially from crust. The ore-forming fluids of two deposits are a mixture of mantle-derived fluids incorporated by crust-derived fluid, and meteoric water. Based on these results, combined with the consideration of the tectonic setting and geological features, we suggest that the two gold deposits in the Kuoerzhenkuola gold field, Sawur gold belt share the same genesis, and are volcanogenic hydrothermal gold deposits occurring in the same caldera.


    V. A. Vanin


    Full Text Available Metamorphosed volcanic rocks of the Ushmukan suite were studied in the Mukodek gold-ore field located in the Baikal-Muya belt in the Northern Baikal area, Russia. The Ushmukan suite shows interleaving of ortoschists which compositions are widely variable. Basalt-andesite-dacite series of normal alkalinity are the substrate of the studied metavolcanic rocks. Based on the set of geochemical characteristics, it is concluded that the rocks were formed in suprasubduction geodynamic conditions corresponding to a mature island arc. The proximity of the geological locations and the similarity of the geochemical characteristics of the volcanic rocks of the Ushmukan suite and rocks of the Kelyan suite (Neoproterozoic, 823 Ma, which have similar compositions, give grounds to consider these two rock suites as age peers. Specific features of gold distribution through the Mukodek gold-ore field are analyzed. Industrial gold contents are recorded only in berezite-listvenite metasomatic rocks of the gold-quartz-sulfide formation which were formed on metavolcanic rocks of the Ushmukan suite. It is concluded that the volcanic rocks, which are specific of the island-arc setting, could be a source of gold for deposits in the Mukodek gold-ore field. 

  7. Research on Technology of Pressure Pretreatment with Oxygen for Refractory Gold Ores

    Liu Shengming; Sun Tichang; Chen Jinghe; Wang Dianzuo


    An combined technology of pressure pretreatment with oxygen on refractory gold ores is pointed out and discussed on this paper, according to the experiments included the test in 1kg grade batch pressure pretreatment with oxygen of the concentrate from the refractory gold ores of Dongbeizhai in Sichuan province, which is called the most refractory gold ores in China. It is shown that gold recovery reach 91.73% in the combined process which is described as follows: The flotation of the sulphide gold ores is under controlled conditions, producing the concentrate for pressure pretreatment with oxygen in acidic medium and the middling for the pressure pretreatment with oxygen in alkaline medium. The thickening and washing process substitute the pressure filtration process of the pulp after pressure pretreatment. The thick slimes of the two kinds of pressure pretreatment were mixed and then enter the CIL process for simplifying the flowsheet. The possible superabundance of acid of pressure pretreatment with oxygen in acidic medium was neutralized by the tailings of flotation and the cost of neutralization will be lower. The combined technology of pressure pretreatment with oxygen has the same advantages as the normal technology of pressure pretreatment and both is helpful for environment protection.

  8. [Biooxidation of a Double-Refractory Gold-Bearing Sulfide Ore Concentrate].

    Bulaev, A G; Kanaeva, Z K; Kanaev, A T; Kondrat'eva, T F


    The efficiency of biooxidation for treatment of a double-refractory gold-bearing sulfide ore concentrate from the Bakyrchik deposit (East Kazakhstan) was defined. The experiments were conducted in two different modes, i.e., with the standard liquid medium and the medium imitating the chemical composition of the Bakyrchik deposit groundwater and containing high concentrations of sodium, magnesium, and chloride. The concentrate contained 17.5% of organic carbon, 6% of pyrite and 13% arsenopyrite. Gold content was 57.5 g t@-1@. Direct gold recovery by cyanidation was very low (2.8%). While biooxidation was efficient in both cases (approximately 90% of sulfide sulfur was oxidized), the efficiency of cyanidation was low (39 and 32%, respectively). This fact suggests high efficiency of biooxidation is insufficient for efficient treatment of double-refractory gold-bearing sulfide ore concentrates.

  9. REE Characteristics of Microfine Disseminated Gold Ores in Danzai,Guizhou

    陈庆年; 周丕康; 等


    Described in this paper are the fundamental characteristics of mineralization of gold ores in the Sandu-Danzhai Hg-Sb-Au ore belt of Guizhou Province,Through systematic sampling of the industrial orebody and alteration zone,the total amount of the rare-earth elements,that of the light rare-earth elements,Eu depletion and other parameters are clarified.There have been distinguished two types of REE distribution patterns:the"Clay type"and the "quartz type" .High-grade orebodies are closely related with silicification,illitization and pyritization.The seven-component diagram of the REEs of even numbers in the periodic table(Bal-asov,1966)is capable of distinguishing ore-bearing from ore-barren deposits.

  10. Pretreatment of copper-bearing refractory gold ores by bio-heap leaching


    The refractory gold ores associated with rich copper and trapped in pyrite and quartz were studied. With conventional technique (all-sliming cyanidation), the gold recovery rate is only 51.78%. To eliminate the negative effects of copper and pyrite on cyanidation and increase the gold recovery rate, the investigation on bio-heap leaching pretreatment was made, by which Cu would be dissolved and gold would be liberated from pyrite. The experiment adopted mixed bacteria, mainly Thiobacillus ferrooxidan (named T. f1), as the bacterial catalyst for bio-preconditioning and was carried out in a PVC column with a diameter of 20 cm and a height of 1.3 m loaded with gold ores. The temperature was controlled between 28 and 30℃, the pH value was kept between 2.0-2.5,and the flux of sprinkling bacterial liquid was maintained 0.80 L/h. After 45-day's bio-oxidization, among the samples sizing from 0to 5 mm, the oxidation rates of Cu, Fe and S were respectively 44.62%, 28.16% and 25.46%, and the gold recovery rate by cyaniding increased to 80.35%. The bio-heap leaching pretreatment can therefore effectively dissolve Cu and liberate gold from pyrite and lead to the increase of gold extraction.

  11. Gold upgrading in metamorphosed massive sulfide ore deposits: Direct evidence from laser-ablation-inductively coupled plasma-mass spectrometry analysis of invisible gold

    Wagner, Thomas; Klemd, Reiner; Wenzel, Thomas; Mattsson, Benny


    The metamorphosed Boliden volcanic-hosted massive sulfide (VHMS) ore deposit, northern Sweden, is characterized by an abundance of massive arsenopyrite ore and unusually high gold enrichments (up to 300-600 g/t) in crosscutting veins and fracture zones. The ore textures observed record progressive recrystallization and porphyroblast growth during meta morphism. We conducted a systematic laser-ablation-inductively coupled plasma-mass spectrom etry (LA-ICP-MS) study on the gold distribution in fine-grained massive arseno-pyrite and pyrite ore, partially recrystallized arsenopyrite ore, and both arsenopyrite and pyrite porphyroblasts found in gold-rich veins. The gold concentrations in massive arseno-pyrite are highest (30-50 ppm on average) and systematically decrease to 0-2.7 ppm with increasing degree of recrystallization. By contrast, gold concentrations in pyrite ore are much lower and do not exceed 0.2 ppm. The LA-ICP-MS data, coupled with textural data, provide the first direct conclusive evidence that gold is progressively liberated from massive sulfide ores during metamorphism and reprecipitated in veins and other low-strain sites. We suggest that such upgrading is the principal mechanism responsible for significant gold enrichment observed in many metamorphosed VHMS deposits worldwide.




    Adsorption capacity of ACFF in cyanide leaching liquor of gold ores was studied with cyanide leaching liquor of gold ores,containing various kinds of ions.The adsorbed leaching liquor was analyzed by atomic emission spectroscopy and colorimetric method.The contents of various kinds. of ions in ACFF were determined with X-ray photoctron spectroscopy.ACFF not only adsorbed gold but also adsorbed arsenic,nickel,zinc,calcium,sulphur,bismuth,copper,iron,silver and cyanide,anion.Atomic percentage of C and those of O,N,Zn,Fe increase and decrease respectively with the increase of the layer depth,while those of Ca,Au,Ag keep constant.

  13. Gold-silver-tellurium mineral assemblages in different ore styles of the Southern Urals VHMS deposits

    Maslennikov, V. V.; Zaykov, V. V.; Maslennikova, S. P.; Tesalina, S. G.; Herrington, R. J.; Buschmann, B.; Becker, K.; Petersen, S.; Orgeval, J. J.; Leistel, M.


    VMS deposits of the South Urals generally show a continuum in degradation and reworking ranging from pristine steep-sided hydrothermal sulphide mounds to deposits dominated by layered strata of clastic sulphides. Four different deposits with varying degrees of degradation in order of increased reworking: (Yaman-Kasy longrightarrow Molodezhnoe longrightarrow Alexandrinskoe longrightarrow Balta-Tau) have been ranged. The influence of sulphide mound destruction and of sea-floor alteration on mineral assemblages was investigated In the pristine Yaman-Kasy sulphide mound gold and silver occur as altaite+tellurium+hessite-stuetzite+sylvanite and later galena+native gold+pyrite assemblages in chalcopyrite+isocubanite-rich linings of former chimney conduits. Chalcopyrite-dominated conduit fragments in clastic ore facies contain native tellurium+gold intergrowths. In the weakly reworked Molodezhnoe deposit gold-silver assemblages only occur in sea-floor altered clastic sulphides on the slope of massive sulphide mounds in bornite- and tennantite-rich ores in association with Cu-Ag sulfides such as jalpaite, mckinstryite, and stromeyerite and rare Au-Ag-tellurides (petzite). The Alexandrinskoe deposit is dominated by clastic ores and here native gold and rare hessite occur together with galena in tennantite-sphalerite-dominated veins of the footwall as well as in drusy sphalerite forming conduits of vent chimneys. An assemblage of electrum+galena+tennantite was observed in secondary chalcopyrite in the outer walls of chimneys. Native gold+stromeyerite are common in bornite-rich clastic sulphides while an assemblage of Ag-sulphosalts+electrum is common in barite-rich ores. In the reworked Balta-Tau deposit Ag-sulphosalts+electrum-kustelite occur often together with tennantite+galena+barite banded ores. Gold-silver-telluride mineralisation in these VMS deposits changes with degree of reworking from Au-tellurides, and native gold+galena+pyrite in pristine sulphide mounds to

  14. Analysis of Ore-Controlling Structures of the Xincheng-Hexi Gold Deposit, Shandong Province, China


    Based on quantitative and semi-quantitative mathematical and mechanical analysis of the shape, motion, structural factors, stress field and deformation field of the ore-hosting faults in the Xincheng-Hexi gold deposit, the ore-controlling features of faults and mineralization mechanism are discussed. It is concluded that the mineralization is controlled by the main faults, subsidiary fractures, joint density, mechanical features and deformation of the faults. The ore bodies are mainly located in the lower part of the convex crest and upper part of the concave trough of the main undulating fault surface. Mineralization is positively correlated to the development of subsidiary fractures and joints, which correspond to zones of low internal stress and high body strain and shear strain. They are favourable positions for mineralization and alteration.

  15. Neutron capture gamma-ray spectroscopy and its analytical applications for gold ore sample using the reactor neutrons

    Hassan, A.M.; El-Kady, A.A.; Rofail, N.B.; Hamouda, I.


    Prompt gamma-rays which immediately follow thermal neutrons capture have been used as a technique for non-destructive elemental analysis for gold ore sample. The thermal column of the Egyptian Research Reactor - 1 (ET-RR-1) was used. This requires a design of a well collimated and thermalized neutron beam. A high resolution and high efficiency Ge (Li) detector was required. In order to estimate the content of gold in its ore, calibration curves were constructed. For testing the results obtained, an empirical formula including the thermal neutron flux, the microscopic cross-section and the absolute efficiency of the detection system were applied. The concentration of gold in its ore sample was found to be as low as 5 ppM. Several elements beside gold could be identified in the ore sample. 10 references.

  16. Geochemical Characteristics and Source of Ore-Forming Fluid of Duolanasayi Gold Deposit, Xinjiang

    肖惠良; 周济元; 王鹤年; 董永观; 季俊峰; 赵宇


    The Duolanasayi gold deposit, 60 km NW of Habahe County in Xinjiang, is a medi-um-large scale gold deposit controlled by the coupled ore-forming processes involving brittle-duc-tile shearing, albitite veins, and post-stage magma solution. Fluid inclusion studies indicate thatthe homogenization temperatures range from 160℃ to 315℃ with the peak values of 220 -300℃. Mineralization pressures are from 21.0 MPa to 64.5 MPa. Ore fluid inclusions containCa2+, K+, Na+, Mg2+; HCO3-, SO242-, HS-, F-, Cl- and Au+( maximum: 5.3 × 10-6),and the mineralizing fluid is a H2O-CO2 system. Sulfur, hydrogen, oxygen and strontium isotop-ic compositions ( δS = - 2.46‰ - - 7.02‰, δ 18 OH2O = 1.65‰ - 12.4‰, δD = - 132.2‰- -51.8‰, (Sr/Sr)i =0.7043 -0.7073) suggest that the ore-forming fluid is the mixture ofmagmatic water, meteoric water, metamorphic water and formation water sealed in rocks andstrata. It is mainly magmatic water in the early stage, and mixing fluid of water, meteoric water,metamorphic water and formation water that occurred in rocks and strata in the major mineraliza-tion stage. The ore-forming materials were derived from the upper mantle or lower crust.

  17. Gold grade of epithermal gold ore at Lamuntet, Brang Rea, West Sumbawa District, West Nusa Tenggara Province, Indonesia

    Ernawati, Rika; Idrus, Arifudin; TBMP, Himawan


    Lamuntet is one of gold ore mining area carried out by the Artisanal Small scale Gold Mining (ASGM) located in West Sumbawa, Indonesia. Most of the miners at this area are not the local miners but also those from other regions. Mineralization of this area is strong identified as low sulfidation epithermal system. There are two blocks of this mining location, namely, Ngelampar block with an area of 0.164 km2 and Song block with an area of 0.067 km2. This study was focused on Ngelampar block. The characteristic of epithermal system is the existence of quartz vein with comb, vuggy, and sugary texture. The aim of this research was to analyze the gold grade and other metals, such as Cu, Ag, Pb, As, Zn, and Hg. The research methods included literature study from previous researches, field work, laboratory work, and interpretation. The literature study was performed on previous researches with similar study area. The field work comprised of direct observation and sampling. Fieldwork was done for a week to obtain gold ore/vein. Sixteen samples were analyzed to obtain the grade of ore/metal. The Hg laboratory analysis was then performed on the six samples with the highest gold grade. Laboratory works were conducted at Intertek Jakarta by using Fire Assay (FA) for gold grade and Atomic Absorption Spectrophotometry (AAS) for Cu, Ag, Pb, As, Zn, and Hg. Results of the analysis showed the range of Au was grade (0.1 ppm - 27.8 ppm), Cu was 26 ppm -1740 ppm, Pb was 101 ppm- >4000 ppm, Zn of 73 ppm- >10,000 ppm, Ag of 3 ppm -185 ppm, As was 150 ppm-6530 ppm, and Hg of 0.08 ppm - 1.89 ppm. L1 and L15 had high grade for all values (Au, Ag, Zn, Cu, As, and Hg). Gold mineralization was formed as electrum because of Ag content is higher than 20%. Associated minerals of the samples in the study area were galena, sphalerite, arsenopyrite, and chalcopyrite which showed the characteristic of rich base metal of Pb, Zn, and Cu at LS epithermal.

  18. Geostatistical Approach to Estimating the Gold Ore Characteristics and Gold Reserves: A Case Study Daksa Area, Quang Nam Province, Viet Nam

    Luan Truong, Xuan; Luong Le, Van; Quang Truong, Xuan


    Daksa gold deposit is the biggest gold deposits in Vietnam. The Daksa geological structure complicated, distributed mainly metamorphosed sedimentary NuiVu formation (PR3-?1nv2). The sulfide gold ore bodies distributed in quartz schist, quartz - biotite related to faut and distribution wing anticline. The gold ore bodies form circuits, network circuits, circuits lenses; fill the cup surface layer of the developing northeast - southwest; is the less than or west longitude north - SE. The results show that, Au and accompanying elements (Ag, Pb and Zn) have correlated pretty closely. All of its consistent with the logarithmic distribution standard, in accordance with the law of distribution of content mineral rare. The structure functions have nugget effect and spherical models with show that Au and accompanying elements special variation are changes. Au contents shown local anisotropy, no clearly anisotropy (K=1,17) and weakly anisotropy (K=1,4). Intensity mineralization of the ore bodies are quite high with demand spherical conversion coefficient ranging from 0.49 to 0.75 and from 0.66 to 0.97 (for other body). With nugget effects, ore bodies shown that it is consistent with mineralization in the ore bodies study, ore erasable, micro vein, infilling fractures in quartz vein. All of variogram presents local anisotropy, indicated gold mineralization at study area has least two-mineralization stages, consistent with the analysis of mineralography samples. By the results of the structure function study, the authors present the system optimization for exploration deposit and used to evaluate gold reserves by Ordinary Kriging. High accuracy of Kriging estimation results are expressed in the minimum Kriging variance, by compare the results calculated by some other methods (such as distance inverse weighting method, ..) and specially compare to the results of a some blocks have been exploited. Key words: Geostat and gold deposits VN. Daksa and gold mineralization. Geostat

  19. Geological characteristics and ore-forming process of the gold deposits in the western Qinling region, China

    Liu, Jiajun; Liu, Chonghao; Carranza, Emmanuel John M.; Li, Yujie; Mao, Zhihao; Wang, Jianping; Wang, Yinhong; Zhang, Jing; Zhai, Degao; Zhang, Huafeng; Shan, Liang; Zhu, Laimin; Lu, Rukui


    The western Qinling, belonging to the western part of the Qinling-Dabie-Sulu orogen between the North China Block and South China Block, is one of the most important gold regions in China. Isotopic dates suggest that the Mesozoic granitoids in the western Qinling region emplaced during the Middle-Late Triassic, and the deposits formed during the Late Triassic. Almost all gold deposits in the western Qinling region are classified as orogenic, Carlin-type, and Carlin-like gold deposits, and they are the products of Qinling Orogenesis caused by the final collision between the North China Block and the South China Block. The early subduction of the Mian-Lue oceanic crust and the latter collision between South Qinling Terrane and the South China Block along the Mian-Lue suture generated lithosphere-scale thermal anomalies to drive orogen-scale hydrothermal systems. The collision-related magmatism also provided heat source for regional ore-forming fluids in the Carlin-like gold deposits. Orogenic gold deposits such as Huachanggou, Liziyuan, and Baguamiao lie between the Shang-Dan and Mian-Lue sutures and are confined to WNW-trending brittle-ductile shear zones in Devonian and Carboniferous greenschist-facies metasedimentary rocks that were highly-deformed and regionally-metamorphosed. These deposits are typical orogenic gold deposits and formed within a Late Triassic age. The deposits show a close relationship between Au and Ag. Ores contain mainly microscopic gold, and minor electrum and visible gold, along with pyrite. The ore-forming fluids were main metamorphic fluids. Intensive tectonic movements caused by orogenesis created fluid-migrating channels for precipitation locations. Although some orogenic gold deposits occur adjacent to granitoids, mineralization is not synchronous with magmatism; that is, the granitoids have no genetic relations to orogenic gold deposits. As ore-forming fluids converged into dilated fractures during the extension stage of orogenesis

  20. Ore-forming fluids in the Dongping gold deposit, northwestern Hebei Province

    FAN; Hongrui


    : 1435-1444.[11]Schwartz, M. O., Determining phase volumes of mixed CO2-H2O inclusions using microthermometric measurements, Mineral Deposita, 1989, 24: 43-47.[12]Brown, P. E., Hagemann, S. G., MacFlincor and its application to fluids in Archean lode-gold deposits, Geochimica et Cosmochimica Acta, 1995, 59: 3943-3952.[13]Fan Hongrui, Xie Yihan, Zhao Rui et al., Dual origins of Xiaoqinling gold-bearing quartz veins: Fluid inclusion evidences, Chinese Science Bulletin, 2000, 45(15): 1424-1430.[14]Chen Yanjing, Li Chao, Zhang Jing et al., Sr and O isotopic characteristics of porphyries in the Qinling molybdenum de-posit belt and their implication to genetic mechanism and type, Science in China, Ser. D, 2000, 43 (supp.): 82-94.[15]Zhang Fuxin, Chen Yanjing, Li Chao et al., Geological and geochemical character and genesis of the Jinlongshan-Qiuling gold deposits in Qinling orogen: Metallogenic mechanism of the Qinling-pattern Carlin-type gold deposits, Science in China, Ser. D, 2000, 43(supp.): 95-107.[16]Chen Yanjing, Guo Guangjun, Li Xin, Metallogenic geodynamic background of gold deposits in Granite-greenstone ter-rains of North China craton, Science in China Ser. D, 1998, 41(2): 113-120.[17]Clayton, R. N., Oxygen isotope exchange between quartz and water, J. Geophys. Res., 1972, 77: 3057-3607.[18]Zhang Ligang, Cheng Zhengshen, Liu Jingxiu et al., Two Stage Water-rock Interaction and Prospecting Cases, Beijing: Geological Publishing House, 1995, 1-231.[19]Jiang Sihong, Nie Fengjun, 40Ar-39Ar geochronology of the Shuiquangou alkaline complex and related gold deposits, Northwestern Hebei, China, Geological Review, 2000, 46(6): 621-627.[20]Taylor, H. P., Oxygen and hydrogen isotope relationships, in Barnes H L(ed.), Geochemistry of Hydrothermal Ore Depos-its, 2nd ed., New York: John Wiley & Sons, 1979, 236-277.[21]Yardley, B. W. D., Post-metamorphic gold-quartz veins from N.W Italy: The composition and origin of the ore fluid, Min

  1. Geochemical Features of Ore Fluid for Gold Deposits Related to Alkaline Rocks in China

    齐金忠; 李莉


    Fluid inclusion studies of 5 gold deposits connected with alkaline rocks show that quartz separated from auriferous quartz veins contains abundant three-phase CO2-NaCl-H2O inclusions and two-phase CO2-dominated ones,measuring 5-20um in diameter,Homogenization temperatures of the fluid inclusions are mostly within the range of 150-300℃,and the salinities,mainly 0.2wt%-12 wt%(NaCl),Gold mineralizations occurred at depths of 1.4-2.8km,The most striking character of fluid composition is that among the cations,Na+ in dominant,followed by K+,Ca2+,among the anions,Cl- is slightly higher than SO42-,In the evaporate,H2O is dominant,followed by CO2,The pH values are mainly within the range of 6.5-8.5,indicating that the ore-forming solutions are alkaline in nature.The hydrogen and oxygen isotopic ratios indicate that the ore fluid is composed mainly of magmatic water.With the dropping of temperature in the ore fluid,the contents of CO2 decreased while the salinity increased.The relations between Au and other components of the ore fluid are discussed in the paper,and it is concluded that in these deposits,Chlorides,H2S,SiO2,CO2, the fluid all are involved in the migration and concentration of Au.

  2. Ore-forming fluids in the Dongping gold deposit, northwestern Hebei Province


    The Dongping gold deposit is contained within an inner contacting zone of the Hercynian Shuiquangou alkali syenite. The ores occur as veins or as replacement bodies. Fluid inclusion observation shows that in early and main mineralizing stages inclusion types are gas and gas-liquid inclusions, respectively. Gas inclusions occur in isolation in vein quartz, their homogenization tem-perature is 372-306℃, and salinity 3.7-1.0 wt% NaCl. Gas-liquid inclusions occur in clusters or healed fractures but do not cut quartz boundary with homogenization temperature 342-267℃ and salinity 1.9-0.8 wt% NaCl. Stable isotope measurements show that at main gold mineralization, hydrogen and oxygen isotopic ratios of the mineralizing fluids are -70.8‰- -108.4‰ and 2.44‰-4.05‰, respectively. Primary ore fluids in Dongping are higher temperature and lower salinity NaCl-CO2-H2O fluids, and come from Yanshanian granitic magmatism. Fluid immiscibility, fluid-rock interactions and meteoric water adding were main reasons for gold deposition.

  3. Rare Earth Element Geochemistry on Magmatic Rocks and Gold Deposits in Shizishan Ore-Field of Tongling, China


    REE geochemical characteristics of the magmatic rocks and gold deposits in Shizishan ore-field of Tongling were studied. Three types of the magmatic rocks have almost the same chondrite-normalized REE patterns, Eu and Ce anomalous values, and ΣREE, ΣLREE/ΣHREE regular changes, which indicates that their magmas come from the same source and their digenetic mechanism is fractional crystallization. In three gold deposits, the mineral ores and related altered rocks have similar chondrite-normalized REE patterns and sharp Eu positive anomalous values. The REE contents reduced from the magmatic rocks to skarnization or alteration magmatic rocks, skarn type ores, sulphide type ores, wall-rocks limestone or marble. The REE geochemical characteristics of the ores and related rocks show that primary fluids originated from magmatic differentiation in lower pressure of shallow crust, ore-forming hydrothermal solutions gained REE and mineralization elements further from leaching the magmatic rocks, then superimposed and reformed the limestones or marbles and deposited ore-forming material.

  4. Determination of gold in copper-bearing sulphide ores and metallurgical flotation products by atomic-absorption spectrometry.

    Strong, B; Murray-Smith, R


    A method is described which is specific for the determination of gold in sulphide copper ores and concentrates. Direct decomposition with aqua regia was found to be incomplete. A carefully controlled roasting stage followed by treatment with hydrochloric acid and then aqua regia was effective for dissolving all the gold. The gold is extracted into 4-methylpentan-2-one (methyli-sobutylketone) then aspirated into a very lean air-acetylene flame and the gold determined by atomic-absorption spectrometry. No interferences were observed from large concentrations of copper, iron or nickel.

  5. Comprehensive recovery of gold and base-metal sulfide minerals from a low-grade refractory ore

    Wen-juan Li; Shuang Liu; Yong-sheng Song; Jian-kang Wen; Gui-ying Zhou; and Yong Chen


    The comprehensive recovery of small amounts of valuable minerals such as gold and base-metal sulfide minerals from a low-grade refractory ore was investigated. The following treatment strategy was applied to a sample of this ore: gold flotation–gold concen-trate leaching–lead and zinc flotation from the gold concentrate leaching residue. Closed-circuit trials of gold flotation yielded a gold concen-trate that assayed at 40.23 g·t−1Au with a recovery of 86.25%. The gold concentrate leaching rate was 98.76%. Two variants of lead-zinc flotation from the residue—preferential flotation of lead and zinc and bulk flotation of lead and zinc—were tested using the middling proc-essing method. Foam from the reflotation was returned to the lead rougher flotation or lead–zinc bulk flotation, whereas middlings from re-flotation were discarded. Sulfur concentrate was a byproduct. The combined strategy of flotation, leaching, and flotation is recommended for the treatment of this kind of ore.

  6. Comprehensive recovery of gold and base-metal sulfide minerals from a low-grade refractory ore

    Li, Wen-juan; Liu, Shuang; Song, Yong-sheng; Wen, Jian-kang; Zhou, Gui-ying; Chen, Yong


    The comprehensive recovery of small amounts of valuable minerals such as gold and base-metal sulfide minerals from a low-grade refractory ore was investigated. The following treatment strategy was applied to a sample of this ore: gold flotation-gold concentrate leaching-lead and zinc flotation from the gold concentrate leaching residue. Closed-circuit trials of gold flotation yielded a gold concentrate that assayed at 40.23 g·t-1 Au with a recovery of 86.25%. The gold concentrate leaching rate was 98.76%. Two variants of lead-zinc flotation from the residue—preferential flotation of lead and zinc and bulk flotation of lead and zinc—were tested using the middling processing method. Foam from the reflotation was returned to the lead rougher flotation or lead-zinc bulk flotation, whereas middlings from reflotation were discarded. Sulfur concentrate was a byproduct. The combined strategy of flotation, leaching, and flotation is recommended for the treatment of this kind of ore.

  7. Rare Earth Elements Geochemistry of Laowan Gold Deposit in Henan Province: Trace to Source of Ore-Forming Materials


    The compositions of REE in quartz and pyrite from the main stage of the Laowan gold deposit in Henan Province and that in quartz from Laowan granite were determined by inductively coupled plasma-mass-spectrometry (ICP-MS) to trace the source of ore-forming materials. Meanwhile, the REE compositions of the deposit ore, granite and metamorphic wall rock were also considered for comparative studies in detail. The range of ∑REE of quartz and pyrite from the deposit ores is 4.18×10-6~30.91×10-6, the average of ∑REE is 13.39×10-6, and the average of ∑REE of quartz in the Laowan granite is 6.68×10-6. There is no distinct difference of REE parameters between the deposit ore quartz and granite quartz. The quartz in gold deposit has the same REE particular parameters as quartzes from Laowan granite, such as δEu, δCe, (La/Yb)N and (La/Sm)N, partition degree of LREE to HREE, especially, the chondrite-normalized REE patterns, but no similarity to those from metamorphic wall rock, which shows that ore-forming hydrothermal fluid is mainly the fluid coming from the Laowan granite magma, rather than metamorphic fluid. Meanwhile, comparison studies on REE features between minerals from the deposit ores and related geological bodies in the deposit show that REE characteristics of minerals can serve as an indicator of ore-forming fluid properties and sources, while the REE characteristics of the bulk samples (such as deposit ores, granites and wall rocks) can not trace the source of the ore-forming materials exactly.

  8. Bioleaching of refractory gold ore (Ⅲ)--Fluid leaching Jinya refractory gold concentrate by Thiobacillus ferrooxidans

    闵小波; 柴立元; 陈为亮; 于霞; 张传福; 邝中


    A novel fluidized-bed reactor was designed and installed for bioleaching in a semi-continuous way,by which a process for bioleaching-cyanidation of Jinya refractory gold arsenical concentrate was studied.The arsenic extraction rate reaches 82.5% after 4-day batch biooxidation of the concentrate under the optimized condition of pH 2.0,ferric ion concentration 6.5 g/L and pulp concentration 10%.And leached rate of gold in the following cyanidation is over 90%.The parameters of three series fluidized-bed reactors exhibit stability during the semi-continuous bioleaching of the concentrate.Arsenic in the concentrate can be got rid of 91% after 6-day leaching.Even after 4 days,82% of arsenic extraction rate was still obtained.The recovery rates of gold are 92% and 87.5% respectively in cyaniding the above bioleached residues.The results will provide a base for further commercial production of gold development.

  9. 甘肃某金矿石中金的赋存状态研究%Occurrence State of Gold in a Gold Ore in Gansu

    王利珍; 瞿思思; 姜楚灵


    Detailed studies were conducted, by using modern measurement methods, on characteristics of gold-loaded minerals and types, forms, particle size, occurrence state, deliberation features of gold ore, so as to provide theoretical basis for beneficiation of a low-grade gold ore in Gansu Province. Results show that gold element in the ores was distributed along the edge, inter-particle, fractures and pores of gold-loaded minerals in the form of natural gold (micro-fine to fine particle), or electrum, or partially embedded in the gold-loaded minerals in form of inclusions. It is concluded from the study that low grade of gold, high content of sulfide, and the complex occurrence of gold are the primary factors affecting gold enrichment and recovery.%为给甘肃某低品位金矿石的选矿试验提供理论依据,通过多种现代测试手段对矿石中主要载金矿物的特征和金矿物的种类、形态、粒度、产出形式、解离特性等方面进行了较详细的研究,结果表明矿石中金部分呈微细粒~微粒自然金或银金矿沿载金矿物的边缘、粒间、裂隙及孔洞充填分布,部分则呈包裹体嵌布在载金矿物内部。影响金矿物富集回收的主要因素是矿石中金品位低、硫化物含量高、金的赋存状态较为复杂。

  10. Application of the superfine fraction analysis method in ore gold geochemical prospecting in the Shamanikha-Stolbovsky Area (Magadan Region)

    Makarova, Yuliya; Sokolov, Sergey; Glukhov, Anton


    The Shamanikha-Stolbovsky gold cluster is located in the North-East of Russia, in the basin of the Kolyma River. In 1933, gold placers were discovered there, but the search for significant gold targets for more than 50 years did not give positive results. In 2009-2011, geochemical and geophysical studies, mining and drilling were conducted within this cluster. Geochemical exploration was carried out in a modification based on superimposed secondary sorption-salt haloes (sampling density of 250x250 m, 250x50 m, 250x20 m) using the superfine fraction analysis method (SFAM) because of complicated landscape conditions (thick Quaternary sediments, widespread permafrost). The method consists in the extraction of superfine fraction (quartz formation are identified within the anomalous geochemical field core zone. 3. In all these prospects, mining and drilling penetrated gold ore bodies within the identified potentially gold zones. The Nadezhda target now has the status of gold deposit.

  11. Helium and argon isotope trace in ore-forming fluid of Sawuer gold belt in Xinjiang, China

    SHEN Ping; SHEN Yuanchao; ZENG Qingdong; LIU Tiebing; LI Guangming


    The helium and argon isotope compositions of fluid inclusions hosted in pyrite have been measured from Kuoerzhenkuola and Buerkesidai gold deposits in Sawuer gold belt, northern Xinjiang. The results show that fluidinclusion 3He/4He ratios are 0.64 Ra-4.25 Ra and 1.16 Ra 9.48 Ra, 40Ar/36Ar ratios are 282-359 and 312-525 for Kuoerzhenkuola and Buerkesidai gold deposits respectively.The ore-forming fluids of two deposits possessed the same source and derived mainly from mantle beneath the island arc (including oceanic crust and oceanic sediments by subduction of oceanic plate). They were diluted by incorporating meteoric water to form a mixture of mantle- and partial meteoric water-derived fluid. The ore-forming fluids of two deposits are of the same evolutionary histories. From the early to the late mineralization stages, the ratios of meteoric water/mantle- derived fluid in ore-forming fluid increased gradually. Based on these results and detailed geological and geochemical studies on the two deposits, it is proposed that the geneses of the two gold deposits are the same, being volcanogenic late-stage hydrothermal gold deposits occurring in the same volcanic apparatus.

  12. Analysis of the Ore-Controlling Structure of Ductile Shear Zone Type Gold Deposit in Southern Beishan Area, Gansu, Northwest China

    Chen Bailin; Wu Ganguo; Ye Dejin; Liu Xiaochun; Shu Bin; Yang Nong


    The ductile shear zone-type gold deposit is a kind that both the ore-forming mechanism and ore-controlling factors are closely related to the ductile shear zone and its evolution. Ductile shear zone develops in Beishan area, Gansu of Northwest China, and develops especially well in the south belt.The controls of the ductile shear zone on gold deposits are as follows. (1) The regional distribution of gold deposits (and gold spots) is controlled by the ductile shear zone. (2) The ductile-brittle shear zone is formed in the evolution process of ductile shear zone and both are only ore-bearing structures and control the shape, attitude, scale, and distribution of mineralization zones and ore-bodies. (3) Compresso-shear ductile deformation results in that the main kind of gold mineralization is altered mylonite type and the main alteralization is metasomatic. (4) Ore-bearing fracture systems are mainly P-type ones, some D-type and R-type ones, but only individual R'-type and T-type ones. (5) Dynamic differentiation and dynamic metamorphic hydrothermal solution resulting from ductile deformation is one of the sources of ore-forming fluid of gold mineralization, and this is identical with that ore-forming materials are mainly from metamorphic rocks, and ore-forming fluid is mainly composed of metamorphic water, and with the fluid inclusion and geo-chemical characteristics of the deposit. (6) There is a negative correlation between the gold abundance and susceptibility anisotropy (P) of the altered mylonlte samples from the deposit, which shows that the gold mineralization is slightly later than the structural deformation. All above further expound the ore-forming model of the ductile shear zone type of gold deposits.

  13. A statistical approach to the experimental design of the sulfuric acid leaching of gold-copper ore

    Mendes F.D.


    Full Text Available The high grade of copper in the Igarapé Bahia (Brazil gold-copper ore prevents the direct application of the classic cyanidation process. Copper oxides and sulfides react with cyanides in solution, causing a high consumption of leach reagent and thereby raising processing costs and decreasing recovery of gold. Studies have showm that a feasible route for this ore would be a pretreatment for copper minerals removal prior to the cyanidation stage. The goal of this experimental work was to study the experimental conditions required for copper removal from Igarapé Bahia gold-copper ore by sulfuric acid leaching by applying a statistical approach to the experimental design. By using the Plackett Burman method, it was possible to select the variables that had the largest influence on the percentage of copper extracted at the sulfuric acid leaching stage. These were temperature of leach solution, stirring speed, concentration of sulfuric acid in the leach solution and particle size of the ore. The influence of the individual effects of these variables and their interactions on the experimental response were analyzed by applying the replicated full factorial design method. Finally, the selected variables were optimized by the ascending path statistical method, which determined the best experimental conditions for leaching to achieve the highest percentage of copper extracted. Using the optimized conditions, the best leaching results showed a copper extraction of 75.5%.

  14. Geochemical Characteristics of Two Types of Ores from Jinshan Shear Zone—hosted Gold Deposit,Jiangxi,with a Discussion on the Mechanism of Two—stage Mineralization

    季峻峰; 刘英俊; 等


    Two types of gold ores,siliceous mylonite and quartz vein,formed at the first and second stages of mineralization respectively, can be clearly recognized in the shear zone-hosted gold deposit at Jinshan, Jiangxi.Similarity in REE and trace elements between the siliceous mylonite and the country rocks indicates that the ore metals were supplied by the surrounding strata during the first stage of mineralization.On the other hand, as indicated by fluid inclusion data,the ore-forming fluid at the second stage was of meteoric origin and the precipitation of gold was caused by phase separation.

  15. Physico-Chemical Modeling of the Sulfo-Arsenide System of Gold Bearing Ore Deposits

    N. V. VILOR


    Full Text Available The existence of gold-arsenic mineralization, the presence of enhanced concentrations of gold in arsenopyrite, especially in its fine grain varieties showing positive gold-arsenic ratios in gold-quartz and gold-pyritic ores indicate the important role of As in hydrothermal gold transport. The most accessible approach to the investigation of these complicated systems is provided by physico-chemical modeling. In the present work the isobaric isothermal potentials (DG°f 298 of thioarsenides, the most important group of arsenic compounds in the solution, have been determined and refined on the basis of the creation of physico-chemical models using the data on the As sulfide solubility in the As – S – O – H system. The data obtained were reconciled with the thermodynamic data available by solving the reverse thermodynamic problem. Numerical physico-chemical modeling has been carried out for a series of tests in both pure water and hydrogen sulfide solutions (0.0032 - 0.011m with the initial pH values from 1.14 to 8.4 in the 25-250°C temperature range under saturated water steam pressure. The computer-calculated constants are included in the modeling of tests on orpiment dissolution in sulfide-sodium solutions. The As2S3ryst solubility in the 25-250°C temperature range has first been obtained. A specific feature of the process is a sharp increase in dissolved arsenic total concentration as the pH value of the hydrothermal phase rises from 4 to 6-7. Concentration increases and gradient decreases with temperature rise. The predominant forms are represented by thioarsenites. Just as in acidic, so in weakly and moderately alkaline solutions the orpiment solubility is caused by the concentration combination of thioarsenous acid H3AsS3 and its oligomers H4As2S50 and H2As2S40. At a temperature of over 200-250°C these concentrations can be compared only with that of the AsOH (HS2o complex of mixed composition.

  16. Main types of gold ore forming systems and their relationship with the paleogeodynamic settings on the Taimyr Peninsula and the Severnaya Zemlya Archipelago

    Proskurnin, Vasiliy; Anatoly, Gavrish; Aleksandra, Bagaeva; Petrushkov, Boris; Shneider, Alexey; Saltanov, Vasily; Stepunina, Maria; Proskurnina, Alina


    Within the Taimyr - Severnaya Zemlya mineragenic province, the Late Paleozoic - Early Mesozoic Kara rare-metal - gold and Byrrangsky coal-bearing - polymetallic mineragenic areas are distinguished. Main geological commercial types of the Kara mineragenic area include manifestations of gold-quartz, gold sulphide-quartz (proper gold ore), and gold-rare metal, gold-bearing copper-molybdenum-porphyry formations. The Riphean - Vendian subduction - collisional and Late Paleozoic - Early Mesozoic repeated collisional (deuterogenic) ore-forming systems play a leading role in their formation. Regardless of the age and formation features, manifestations of proper gold ore formations are controlled by a common factor, the degree of metamorphism of host rocks - not above the sericite-biotite subfacies of the greenschist facies, and belong to the group of hydrothermal-metasomatic ore forming systems conditioned by alkali-acid differentiation of matter in temperature gradient field with ore concentration in mesozone. Depending on the host Precambrian formations, Kara Late Paleozoic - Early Mesozoic mineragenic area is subdivided into Mininsky-Bolshevistsky flysch-terrigenous carbonaceous zone with manifestation of zonal regional metamorphism of the andalusite-sillimanite type (Arctida passive margin) and Shrenk-Faddey volcanogenic-carbonate-terrigenous carbonaceous zone with ophiolites (accretion prism of Siberia). For the Riphean - Early Vendian endogenous manifestations, the following main types of gold ore forming systems are distinguished: in the passive marginal Mininsky-Bolshevistsky zone - early collisional metamorphic-hydrothermal in terrigenous carbonaceous complexes (Valterovsky, Voskresensky, Litkensky ore zones) and late collisional plutonic-hydrothermal in allochthonous granitoids of S-type (Martovsky-Nikitinsky ore cluster); in the accretionary Shrenck-Faddey zone - subduction-collisional plutonic-metamorphic-hydrothermal (Zhilninsky, Leningradsky ore zones) in

  17. 山东某金矿石浮选试验%Flotation Experiments of a Gold Ore in Shandong

    李艳军; 陈波


    The gold particle in a quartz-vein type gold ore with low sulfur in Shandong is uniform granularity,and exists in pyrite or quartz,in form of fissure gold and inclusion gold.Research of the technical conditions for grinding and separation of the ore showed that under the grinding fineness of-0.074 mm 80%,gold concentrate with gold grade of 61.33 g/t,and recovery of 93.73% was achieved by the process of one roughing,two scavengings,two cleanings and middles back to the process in turn.%山东某低硫石英脉型金矿石中的金粒度较均匀,以裂隙金和包裹金的形式赋存于黄铁矿和石英中.对该矿石的磨选工艺技术条件研究表明:在磨矿细度为-0.074 mm占80%条件下,采用1粗2扫2精、中矿顺序返回流程处理,可获得金品位为61.33 g/t,回收率为93.73%的金精矿.

  18. A Study on the Geological—Geochemical Dynamics of Hydrothermal Ore Deposition as Exemplified by the Muping—Rushan Gold Deposit Belt,Eastern Shandong,China

    赵伦山; 高太忠; 等


    This paper presents a method of establishing a hydrothermal ore-forming reaction system.On the basis of the study of four typical hydrothermal deposits,the following conclusions concerning geochemical dynamic controlling during hydrothermal mineralization have been sions concerning geochemical dynaamic controlling during hydrothermal mineralization have been drawn:(1)The regional tectonic activities control the concentration and dispersion of elements in the ore-forming process in terms of their effects on the thermodynamic nature and conditions of the ore-forming reaction system.(2)During hydrothermal mineralization the activites of ore-bearing faults can be divideb into two stages:the brittle splitting stage and the brittle-tough tensing stage,which would create characteristically different geodynamic conditions for the geochemical thermodynamic ore-forming system.(3)The hydrothermal ore-forming reaaction system is an open dynamic system.At the brittle splitting stage the system was so strongly supersaturated and unequilibrated as to speed up and enhance the crystallization and differentiation of ore-forming fluids.And at the brittle-tough tensing stage,the ore-forming system was in a weak supersaturated state;with decreasing temperature and pressure the crystallization of oreforming material would show down,and it can be regarded as an equilibrated state.(4)In the lates stages of hydrothermal evolution,gold would be concentrated in the residual ore-forming solution.The pulsating fracture activite in this stage led to the crush of pyrite ore and it was then filled with gold-enriched solution,forming high-grage“fissure”gold ore.This ore-forming process could be called the coupling mechanism of ore formation.

  19. An abbreviated fire-assay atomic-absorption method for the determination of gold and silver in ores and concentrates.

    Moloughney, P E


    A simplified scheme, combining aspects of the classical fire-assay with an atomic-absorption finish, is presented for the determination of gold and silver in ores and concentrates. The lead assay button is scorified to approximately 2 g and then parted in nitric acid. The filtrate is analysed by AAS for silver; the residue is dissolved in aqua regia and subsequently analysed for gold by AAS. The precision and accuracy of the method have been established by application to four diverse certified reference materials. The proposed method eliminates the need for such time-consuming steps as inquartation, multiple scorifications, and cupellation.

  20. Explosion-assisted preparation of dispersed gold-bearing different-grade ore for selective mining

    Trubachev, AI; Zykov, NV


    It is found that there are transient zones (between quality and off-quality ore areas) with the respective content of useful component in an ore body, and a variant of explosive treatment of such zones before the selective mining is put forward. Practicability of two processing technologies is evaluated: processing of high-grade and low-grade ore from the transient zones and heap leaching of metals from the low-grade and impoverished ore. Open mining technology is conventional truck-and-shovel scheme, with distributed ore flows to processing plant and (or) to heap leaching, which generally enhances the mine efficiency.

  1. Sources of ore-forming fluids and metallic materials in the Jinwozi lode gold deposit, eastern Tianshan Mountains of China

    LIU; Wei(刘伟); LI; Xinjun(李新俊); DENG; Jun(邓军)


    This paper presents gas compositions and H-, O-isotope compositions of sulfide- and quartz-hosted fluid inclusions, and S-, Pb-isotope compositions of sulfide separates collected from the principal Stage 2 ores in Veins 3 and 210 of the Jinwozi lode gold deposit, eastern Tianshan Mountains of China. Fluid inclusions trapped in quartz and sphalerite are dominantly primary. H- and O-isotopic compositions of pyrite-hosted fluid inclusions indicate two major contributions to the ore-forming fluid that include the degassed magma and the meteoric-derived but rock 18O-buffered groundwater. However, H- and O-isotopic compositions of quartz-hosted fluid inclusions essentially suggest the presence of groundwater. Sulfide-hosted fluid inclusions show considerably higher abundances of gaseous species CO2, N2, H2S, etc. Than quartz-hosted ones. The linear trends among inclusion gaseous species reflect the mixing tendency between the gas-rich magmatic fluid and the groundwater. The relative enrichment of gaseous species in sulfide-hosted fluid inclusions, coupled with the banded ore structure indicating alternate precipitation of quartz with sulfide minerals, suggests that the magmatic fluid has been inputted to the ore-forming fluid in pulsation. Sulfur and lead isotope compositions of pyrite and galena separates indicate an essential magma derivation for sulfur but the multiple sources for metallic materials from the mantle to the bulk crust.

  2. Formation conditions of high-grade gold-silver ore of epithermal Tikhoe deposit, Russian Northeast

    Volkov, A. V.; Kolova, E. E.; Savva, N. E.; Sidorov, A. A.; Prokof'ev, V. Yu.; Ali, A. A.


    The Tikhoe epithermal deposit is located in the Okhotsk-Chukotka volcanic belt (OChVB) 250 km northeast of Magadan. Like other deposits belonging to the Ivan'insky volcanic-plutonic depression (VTD), the Tikhoe deposit is characterized by high-grade Au-Ag ore with an average Au grade of 23.13 gpt Au and Au/Ag ratio varying from 1: 1 to 1: 10. The detailed explored Tikhoe-1 orebody is accompanied by a thick (20 m) aureole of argillic alteration. Pyrite is predominant among ore minerals; galena, arsenopyrite, sphalerite, Ag sulfosalts, fahlore, electrum, and küstelite are less abundant. The ore is characterized by abundant Sebearing minerals. Cu-As geochemical specialization is noted for silver minerals. Elevated Se and Fe molar fractions of the main ore minerals are caused by their formation in the near-surface argillic alteration zone. The veins and veinlets of the Tikhoe-1 ore zone formed stepwise at a temperature of 230 to 105°C from Nachloride solution enriched in Mg and Ca cations with increasing salinity. The parameters of the ore-forming fluid correspond to those of epithermal low-sulfidation deposits and assume the formation of high-grade ore under a screening unit of volcanic rocks. In general, the composition of the ore-forming fluid fits the mineralogy and geochemistry of ore at this deposit. The similarity of the ore composition and parameters of the ore-forming fluid between the Tikhoe and Julietta deposits is noteworthy. Meanwhile, differences are mainly related to the lower temperature and fluid salinity at the Julietta deposit with respect to the Tikhoe deposit. The fluid at the Julietta deposit is depleted in most components compared with that at the Tikhoe deposit except for Sb, Cd, and Ag. The results testify to a different erosion level at the deposits as derivatives of the same ore-forming system. The large scale of the latter allows us to predict the discovery of new high-grade objects, including hidden mineralization, which is not exposed at

  3. Isotopic indication to source of ore materials and fluids of the Wangfeng gold deposit in Tianshan: A case study of metallogenesis during collisional orogenesis

    陈华勇; 鲍景新; 张增杰; 刘玉琳; 倪培; 凌洪飞


    The Wangfeng gold deposit is one of the five most important gold deposits in the Tian-shan. Studies of its metallogenic time, space, geodynamic background, ore feature and ore fluid have proved that the deposit formed in the late Paleozoic continental collision, and consequently is a suitable delegate to probe mineralizing regularities during collisiona! orogenesis. Isotopic studies including O, D, C, S, Pb and Sr reveal ore materials derived from sedimentary association (including carbonate and sulfate), which further refers to the Hercynian carbonate-silicolite-argillite formation north to Wangfeng camp. At the end of Paleozoic, the southward intracontinental subduction of Hercynian synthem along the Hongwuyueqiao fault down to the Central Tianshan terrane induced large-scale fluidization which extracted and out-transported ore materials from Hercynian synthem upto shallow fair positions, and finally resulted in the formation of the Wangfeng deposit. This study excludes the possibility of other tecton

  4. 复杂矿石中金的化学物相分析进展%Chemical Phase Analysis of Gold in the Complex Gold Ore and Its Develop-ment



    The main occurrence states of gold in nature mainly is fine and discrete free gold in the rockymineral and henoboer minerals.It contains uncovered nature gold,linked gold and wrapped gold.So Chemical phase analysis of gold is to measure gold content in various mineral.It is discussed that how to determine the Chemical phase analysis in the complex gold ore.At the same time,it also presents the progress in gold of chemical phase analysis in recent years,including determination of different valence state gold,the occurrence of invisible gold in gole ore (especially in sulphide ore) and the development of chemical phase analysis in refractory gold ore.%  金在自然界主要以细小自然金状态存在于各种脉石矿物或载体矿物中,有单体金、连生金和包裹金,因此金矿石中金的化学物相分析主要是分析金在各种(类)矿物中的含量。本文论述了几种复杂矿石中金化学物相分析的方法,简要介绍了金的化学物相分析近几年来取得的进展,包括不同价态金的测定、“不可见金”在矿物中(特别是在硫化矿)的存在形式,从而为相关工作人员提供金的化学物相分析数据。


    王建平; 戚开静; 杨立强


    Through gathering basic data of 258 gold ore deposits in China, the paper proposes that enough investment on gold exploration should be ensured. Also we should strengthen study on gold ore-forming theory and develop new technologies and new methods in order to enhance the effect of gold ore exploration. By this way, we can increase gold reserves to meet the demands of gold production.%通过对中国258个金矿床资料的统计,简析了中国金矿床在发现年代、规模、类型以及找矿关键因素等方面的一些规律,提出新时期中应保障黄金勘查工作的投入,加强金成矿理论研究,发展完善找金新技术、新方法,以提高金矿找矿的成效,不断增加地质储量,满足黄金生产的需要.

  6. Thermodynamics and technology of extracting gold from low-grade gold ore in system of NH4Cl-NH3-H2O


    According to the principles of simultaneous chemical equilibrium and electronic charge neutrality, the thermodynamics of Au-NH4Cl-NH3-H2O system was studied by using the exponential computation method and through MATLAB programming, and the solid figure of potential-c(NH4Cl)-c(NH4OH) was drawn. The results show that when the sum concentration of Au+ and Au3+ is equal to5 × 10-5 mol/L, ψ(Au+/Au) is about -0.2 V; when the sum comes up to 0.5 mol/L, the value of ψ(Au+/Au) increases to 0.2 V. In this case, ψ(O2/OH-) is as high as 0.7 V. This means that it is feasible to extract gold in this system. In addition, to predict the feasibility of reducing gold from the Au(Ⅰ)-NH4Cl-NH3-H2O system with copper or zinc powder, the solid figures of potential-c(NH4Cl)-c(NH4OH)for both systems of Cu-NH4Cl-NH3-H2O and Zn-NH4Cl-NH3-H2O were also drawn. The results indicate that both copper and zinc powders can reduce Au+ into metal gold, and zinc powder can also reduce H2O into H2, while copper powder can not. The leaching results of a cuprous gold ore show that the extraction of gold can reach 80% in this system. The preliminary results of reduction with copper and zinc powders show that with deoxygenizing, the reduction effects are relatively good.

  7. Advances in geophysical technologies for the exploration and safe mining of deep gold ore bodies in the Witwatersrand basin, South Africa

    Durrheim, RJ


    Full Text Available -1 Proceedings of the Twelfth Biennial Meeting of the Society for Geology Applied to Mineral Deposits, Uppsala, Sweden, 12-15 August 2013 Advances in geophysical technologies for the exploration and safe mining of deep gold ore bodies in the Witwatersrand...

  8. Childhood Lead Poisoning Associated with Gold Ore Processing: a Village-Level Investigation—Zamfara State, Nigeria, October–November 2010

    Lo, Yi-Chun; Dooyema, Carrie A.; Neri, Antonio; Durant, James; Jefferies, Taran; Medina-Marino, Andrew; de Ravello, Lori; Thoroughman, Douglas; Davis, Lora; Dankoli, Raymond S.; Samson, Matthias Y.; Ibrahim, Luka M.; Okechukwu, Ossai; Umar-Tsafe, Nasir T.; Dama, Alhassan H.


    Background: During May–June 2010, a childhood lead poisoning outbreak related to gold ore processing was confirmed in two villages in Zamfara State, Nigeria. During June–September of that year, villages with suspected or confirmed childhood lead poisoning continued to be identified in Zamfara State. Objectives: We investigated the extent of childhood lead poisoning [≥ 1 child with a blood lead level (BLL) ≥ 10 µg/dL] and lead contamination (≥ 1 soil/dust sample with a lead level > 400 parts per million) among villages in Zamfara State and identified villages that should be prioritized for urgent interventions. Methods: We used chain-referral sampling to identify villages of interest, defined as villages suspected of participation in gold ore processing during the previous 12 months. We interviewed villagers, determined BLLs among children lead. Results: We identified 131 villages of interest and visited 74 (56%) villages in three local government areas. Fifty-four (77%) of 70 villages that completed the survey reported gold ore processing. Ore-processing villages were more likely to have ≥ 1 child lead poisoning (68% vs. 50%, p = 0.17) or death following convulsions (74% vs. 44%, p = 0.02). Soil/dust contamination and BLL ≥ 45 µg/dL were identified in ore-processing villages only [50% (p lead poisoning or lead contamination was 3.5 times as high in ore-processing villages than the other villages (95% confidence interval: 1.1, 11.3). Conclusion: Childhood lead poisoning and lead contamination were widespread in surveyed areas, particularly among villages that had processed ore recently. Urgent interventions are required to reduce lead exposure, morbidity, and mortality in affected communities. PMID:22766030

  9. Study on the Physical and Chemical Conditions of Ore Formation of Hetai Ductile Shear Zone-Hosted Gold Deposit and Discovery of Melt Inclusions

    李兆麟; 翟伟; 李文; 石贵勇; 文拥军


    The Hetai ductile shear zone-hosted gold deposit occurs in the deep-seated fault mylonite zone of the Sinian-Silurian metamorphic rock series. In this study there have been discovered melt inclusions, fluid-melt inclusions and organic inclusions in ore-bearing quartz veins of the ore deposit and mylonite for the first time. The homogenization temperatures of the various types of inclusions are 160℃, 180 - 350℃, 530℃ and 870℃ for organic inclusions, liquid inclusions, two-phase immiscible liquid inclusions and melt inclusions, respectively. Ore fluid is categorized as the neutral to basic K+ -Ca2+ -Mg2+ -Na+ - SO2- 4-HCO3-Cl- system. The contents of trace gases follow a descending order of H2O>CO2>CH4>(or < ) H2>CO>C2H2>C2I-I6>O2>N2.The concentrations of K , Ca2 + ,SO2-4,HCO3-,Cl- H2O and C2H2 in fluid inclusions are related to the contents of gold and the Au/Ag ratios in ores from different levels of the gold deposit. This is significant for deep ore prospecting in the region. Daughter minerals in melt inclusions were analyzed using SEM. Quartz, orthoclase, wollastonite and other silicate minerals were identified. They were formed in different mineral assemblages.This analysis further proves the existence of melt inclusions in ore veins. Sedimentary metamorphic rocks could form silicate melts during metamorphic anatexis and dynamic metamorphism, which possess melt-solution characteristics. Ore formation is related to the multi-stage forming process of silicate melt and fluid.


    HU Bin; DAI Ta-gen; XIE Li-hua


    @@ The Lancangjiang tectonic zone in Western Yunnan is an important magmatic,metamorphic and tectonic mobile zone of Southwestern China,whose geotectonic location is very unique.It is characterized by complex geological structures,perfectly developed strata,frequent magmatic activities,,various degrees of metamorphism,rich ore resources and lots of metal deposits,thus formed a centralized zone of mineralization and also constituted one of the important metallogenic belts of noble and nonferrous metal deposits.

  11. A fire-assay and wet chemical method for the determination of palladium, platinum, gold, and silver in ores and concentrates.

    Moloughney, P E


    A method is presented for the determination of palladium, platinum, gold and silver in ores and concentrates by a fire-assay and wet chemical technique. After parting of the lead assay button with dilute nitric acid, and separation of the solution from the residue, the palladium and platinum in the solution are precipitated by the addition of stannous chloride, with tellurium as collector. The resulting precipitate is combined with the gold residue and dissolved in aqua regia, then the solution is analysed for palladium, platinum and gold by atomic-absorption spectrophotometry (AAS). Silver is determined in the original solution by AAS before the reduction step.

  12. Evolution of ore-forming fluids in the Sawayaerdun gold deposit in the Southwestern Chinese Tianshan metallogenic belt, Northwest China

    Chen, Huayong; Chen, Yanjing; Baker, Michael J.


    The Sawayaerdun gold deposit was discovered in the early 1990s and is the largest orogenic-gold deposit in the Chinese Tianshan. Gold mineralization occurs in quartz veins, which are hosted in carbonaceous metasediments and controlled by faults and fractures. Three major hydrothermal events can be identified at Sawayaerdun: An early barren quartz vein stage, middle stage quartz veins with pyrite and gold mineralization and late carbonate (-quartz) veins. Fluid inclusion studies of quartz, pyrite and carbonate formed during the major hydrothermal stages show distinct changes in fluid, temperature, composition and redox conditions occurred during fluid evolution. Three types of fluid inclusions have been identified at Sawayaerdun: H2O + NaCl (L + V), H2O + NaCl + CO2 (L + V) and CO2 (L + V). Fluids trapped in early barren quartz have high temperatures (280-420 °C), low salinities (quartz formation, resulting in the generation of coexisting fluid inclusions with distinguishable vapor/liquid ratios and salinities. The compositional difference between fluids trapped in pyrite and quartz indicate fluid mixing may have occurred during the mineralization stage. The oxidized fluids, probably a mixture of meteoric water and fluids generated during water-host rock interaction, emerged into the ore-forming system to generate extensive metals precipitation. The fluid immiscibility and fluid mixing are most likely caused by pressure decrease during Late Paleozoic uplift and erosion in the Chinese Southern Tianshan area. Comparison of fluids between four major mineralization zones at Sawayaerdun indicate that zone II is similar to the most important zone IV and the order of similarity is probably zone II > XI > I, which could be applied to the future mineral exploration in this area.

  13. SR-XRFA in Biogeochemical Studies: Elemental Composition of Larch Tissues (Larix cajanderi Mayr.) of the Kuranakh Gold ore Field (Russia, Yakutia)

    Artamonova, Svetlana Yu.; Zhuravskaya, Alla N.

    Technogenic impact on the elemental composition of larch (Larix cajanderi Mayr.) in the Kuranakh Gold ore field (Russia, Yakutia) is considered. Elemental composition of the larch tissues was determined by means of X-ray fluorescence measurements with synchrotron radiation at the "Siberian Synchrotron and Terahertz Radiation Center" based on VEPP-3 of the Budker Institute of Nuclear Physics SB RAS. Comprehensive possibilities of the X-ray fluorescence measurements along with the simple preparation of biological samples, allowed us to carry out valuable biogeochemical studies. New data on the accumulation of macroelements K, Ca, Mn, Fe, biophilic microelements Cu, Zn, chalcophilous Mo, Pb, Ag, As, Sb, Ga, Cd, Tl, rare lithophilous Rb, Sr, Zr, Y, Nb, in the tissues of larch (Larix cajanderi Mayr.) of the natural taiga landscape and the tailing dump in the Kuranakh Gold ore field were obtained. The results allow us to assess both natural and technogenic biogeochemical anomalous aureole of gold mining areas.

  14. Multielemental analysis of Migori (Southwest, Kenya) artisanal gold mine ores and sediments by EDX-ray fluorescence technique: implications of occupational exposure and environmental impact.

    Odumo, O B; Mustapha, A O; Patel, J P; Angeyo, H K


    The results of heavy element profiling of the gold ores and sediments associated with the artisanal gold mining activities of the Migori gold belt of Southwestern Nyanza, Kenya, were reported in this paper. The analysis was made to assess the occupational exposure of the miners as well as to investigate the environmental impact of toxic heavy metals. Gold ores and sediments from the artisanal gold processing were sampled in four artisanal gold mining areas: Osiri A, Osiri B, Mikei and Macalder (Makalda) and analyzed for heavy elemental content using (109)Cd radioisotope excited EDXRF spectrometry technique. Analysis consisted of direct irradiating of sample pellets. The concentrations of major elements detected were: titanium (711.41-10,766.67 mg/kg); cobalt (82.65-1,010.00 mg/kg); zinc (29.90-63,210 mg/kg); arsenic (29.30-8,246.59 mg/kg); gold (14.07-73.48 mg/kg); lead (16.31-14,999.40 mg/kg) and mercury (16.10-149.93 mg/kg). The average concentration of the heavy toxic metals i.e. arsenic, lead, titanium and zinc were found to be above 50 mg/Kg as recommended by World Health Organization.

  15. 贫硫化物稀疏浸染型金矿石提金试验研究%Experimental research on gold extraction from loosely disseminated gold ores with little sulfide

    沈永宇; 苑仁财; 霍明春; 姚雨龙; 袁振航; 田野


    对云南某贫硫化物稀疏浸染型金矿石进行了提金试验研究。其结果表明:氰化工艺不适宜处理该类矿石;采用原矿重选浮选闭路工艺流程,可获得重选精矿金品位464.20 g/t,金回收率30.95%,浮选精矿金品位66.32 g/t,金回收率57.60%,总回收率88.55%的良好指标。%Experimental research has been carried out to gold extraction from one loosely disseminated gold ore with little sulfide .The results show that cyanidation is not suitable for such ores .But raw ore gravity separation-closed circuit flotation process achieves satisfactory results ,with gravity separation gold concentrate grade of 464.20 g/t,gold recovery rate of 30.95%;flotation gold concentrate grade of 66.32 g/t,gold recovery rate of 57.60%,total recovery rate of 88.55 %.

  16. Study on the Physical and Chemical Conditions of Ore Formation of Hetai Ductile Shear Zone—Hosted Gold Deposit and Discovery of Melt Inclusions

    李兆麟; 翟伟; 等


    The Hetai ductile shear zone-hosted gold deposit occurs in the deep-seated falut mylonite zone of the Sinian-Silurian metamorphic rock series.In this study there have been discovered melt inclusions,fluid-melt inclusions and organic inclusions in ore-bearing ruartz veins of the ore deposit and mylonite for the first time.The homogenization temperatures of the various types of inclusions are 160℃,180-350℃,530℃and 870℃ for organic inclusions,liquid inclsions two-phase immiscible liquid inclusions and melt inclusion,respectively,Ore fluid is categoriezed as the neutral to basic K+-Ca2+-Mg2+-Na+-SO42--HCO3-Cl- system.The contents of trace gases follow a descending order of H2O>CO2>CH4>(orCO>C2H2>C2H6>O2>N2.The concentrations of K+,Ca2+,SO42-,HCO3-,Cl-,H2O and C2H2 in fluid inclusions are related to the contents of gold and the Au/Ag ratios in from different levels of the gold deposit.This is significant for deep ore prospecting in the region.Daughter minerals in melt inclusions were analyzed using SEM.Quartz,orthoclase,wollastonite and other silicate minerals were identified.They were formed in different mineral assemblages.This analysis further proves the existence of melt inclusions in ore veins.Sedimentary metamophic rocks could form silicate melts during metamorphic anatexis and dynamic metamorphism,which possess melt-soulution characteristics.Ore formation is related to the multi-stage forming process of silicate melt and fluid.

  17. Process Mineralogy Study on the Oxidized Ore in a Gold Deposit%某金矿床氧化矿石工艺矿物学研究

    杨磊; 史光大; 刘飞燕


    The oxidized ore mined from a gold deposit contained 8.1g/t Au,82.5g/t Ag and 0.94%Cu. The gold is mainly occurred as native gold,electrum,the silver is mainly occurred as orgentojarosite,horn-silver,and the copper is mainly occurred as cuprite,tenorite,azurite in the ore. The oxidizing rate of the ore is higher,the mouse-eaten and crevasse are developed,and the permeability of the ore is satisfactory. Therefore,the ore is suitable leaching treatment. However,owing to the content of clay is relatively high,and the oxidized copper minerals are soluble in cyanide solution and resulted in production of Cu(CN)2-3 ion that is an important factor influencing recovery of gold and silver. Thus,a technological flowsheet of desliming-wet pretreatment-cyanide leaching of gold and silver was recommended,so as to realize comprehensive recovery of gold,silver and copper from this kind of ore.%某金矿床氧化矿石含金8.1g/t,含银82.5g/t,含铜0.94%.金主要以自然金、银金矿形式存在,银主要以银铁矾,角银矿形式存在,铜主要以赤铜矿、黑铜矿、蓝铜矿形式存在.矿石氧化率高,孔洞、裂隙发育,渗透性良好,适宜湿法浸出.由于粘土矿物含量高,氧化铜矿物易溶于氰化物溶液,并产生影响金、银回收的Cu(CN)2-3离子,因此推荐采用脱泥→湿法预处理→氰化浸出金、银的工艺流程,综合回收矿石中金、银、铜.

  18. 75 FR 22469 - National Emission Standards for Hazardous Air Pollutants: Gold Mine Ore Processing and Production...


    ...- 1990s. Also, a number of facilities had carbon adsorption beds to control mercury emissions on various... adsorption process, the gold loaded carbon (which also contains mercury and other constituents) is moved into... in the pregnant solution are concentrated through adsorption onto activated carbon. If mercury...

  19. Ore features and gold occurrence in Yinwagou Gold Deposit,Gansu Province%甘肃阴洼沟金矿床矿石特征及金的赋存状态研究

    赵民; 郭月琴; 赵国斌; 温志亮; 杨鹏飞; 李普涛; 吴天娇


    Characteristics of gold minerals and the occurrence of gold have been determined in Yinwagou Gold Deposit ,on the basis of systematic laboratory study ,such as electron microscope observation ,multi-element analysis ,e-lectronic microprobe energy spectrum analysis , electronic microprobe wavelength spectrum analysis , mineral phase a-nalysis .The result shows the gold ores mainly have three different mineralogical types ,that is low sulphide altered rock type gold ore,low sulphide cataclastic quartz-vein type gold ore and low sulphide ankerite -albite-quartz-vein type gold ore ,and Au is the only one industrially valuable element;the metallic mineral content in the ore is low and they are mainly limonite ,hematite and pyrite;non-metallic minerals are mainly quartz ,followed by sericite ,carbonate min-erals,feldspar,chlorite and kaolinite; gold minerals are native gold,and the average fineness of native gold is 975;The main type of dissemination is fissure gold ,followed by inclusion gold ,few in the form of the intergranular gold;grain size of native gold is dominated by fine visible gold ,followed by microgranular gold .Native gold is primarily visi-ble gold,followed by microscopic gold .%为了查清阴洼沟金矿床矿石特征及金的赋存状态,采用电子显微镜、多元素分析、电子探针能谱分析、电子探针波谱分析、物相分析等技术方法,对阴洼沟金矿床的金矿石、金矿物进行了系统的研究.研究结果表明:金矿石工艺类型主要有少硫化物蚀变岩型金矿石、少硫化物碎裂石英脉型金矿石和少硫化物铁白云石-钠长石-石英脉型3种,且有工业价值的元素只有Au;矿石中金属矿物含量较低,主要是褐铁矿、赤铁矿及黄铁矿,非金属矿物主要是石英,其次是绢云母、碳酸盐矿物、长石、绿泥石及高岭石;金矿物为自然金,金成色平均为975;金的嵌布类型以裂隙金为主,其次为包裹金,粒间金含量较少;自然金以细

  20. Chemical changes during alteration of volcanic rocks and gold ore formation, La Libertad, Nicaragua

    Darce, M.; Levi, B.; Nyström, J. O.

    A chemical comparison between altered and unaltered basic lavas from a Tertiary epithermal gold deposit at La Libertad and its surroundings in central Nicaragua shows that chemical changes associated with the geothermal field type of alteration centered at the mining district reach more than 5 km away from it. Titanium seems to have been immobile, H 2O, CO 2, K, and S have been added, and Ni, Mg, and Cl partly lost from the fossil geothermal system. Gold, originally concentrated in the glass of basic lavas, was leached during zeolite facies conditions and precipitated with silica in fractures, forming veins in the center of the geothermal field. An estimate shows that the amount of Au released during the alteration was sufficient to form the La Libertad deposit.

  1. 原子吸收光谱法测定矿样中金%Measurement of gold in sample ore by atomic absorption spectroscopy



    After the sample is ignited in 650℃ and cold digested in aqua regia (1+1),gold is enriched by foamed plastics and is released by thiourea solution.The gold in the sample ore is measured by flame atomic absorption spectroscopy.This method is suit for measurement of gold in rock minerals which contains more than 0.05×10-6 gold.%试样经650℃灼烧,王水(1+1)冷浸泡分解试样,利用泡沫塑料富集金,采用硫脲溶液解脱金,用火焰原子吸收光谱法测定矿样中的金,本法适用岩石矿物中0.05×10-9以上金的测定。

  2. 某难浸金矿的次氯酸钠浸出研究%Study on Leaching of Refractory Gold Ore with Sodium Hypochlorite

    杨聪; 晋克勤; 唐道文; 王锐


    采用次氯酸钠对贵州某难浸金矿进行浸出,考察次氯酸钠浓度,浸出时间和温度对金浸出率的影响.结果表明,次氯酸钠不仅可氧化分解矿石中的FeAsS和FeS2,同时还可以打开包裹的金;在下述优化条件下,金浸出率可达到75%以上:次氯酸钠质量浓度0.6 mol/L,pH 13~14,液固比6,35℃浸出4h.%One refractory gold ore in Guizhou Province was leached with sodium hypochlorite.The effects of concentration of sodium hypochlorite, leaching time and temperature on leaching rate of gold were investigated.The results show that sodium hypochlorite not only oxidizes FeAsS and FeS2 in gold ore, but also opens the encapsulated gold.The leaching rate of gold is above 75% under the following optimum conditions including concentration of sodium hypochlorite of 0.6 mol/L, pH of 13~14, ratio of liquid to solid of 6, leaching time of 4 h, and temperature of 35 ℃.


    刘洪; 吕新彪; 刘阁; 尚世超; 李春诚; 柯昌辉; 王玉奇; 胡庆成


    河南省罗山县金城金矿位于桐柏-大别造山带北侧,矿体受北西西向韧性剪切带控制,呈脉状、透镜状产于中元古界浒湾组变质岩中.根据矿物共生组合和脉体穿插关系,将热液成矿作用分为3个阶段:石英-金-黄铁矿阶段、石英-金-多金属硫化物阶段、石英萤石-碳酸盐矿物阶段.本文在详细分析金城金矿床成矿地质背景、矿床地质特征的基础上,研究该矿床各阶段石英和萤石中流体包裹体,以及石英的氢、氧同位素特征.包裹体研究表明该金矿床的成矿流体分3个阶段,为中低温、中低盐度、低密度体系.成矿流体的δD为-72.0‰~-86.6‰(均值-79.0‰),δ18O值为-5.98‰~+-4.1‰(均值-0.32%),氢氧同位素分析表明初始成矿流体来源自岩浆热液,后期有大气降水成分加入.各阶段的流体具有沿韧性剪切带从深部到浅部,从高温到低温,从高压到低压运移和演化的趋势,最终在浅部构造有利的导矿-容矿构造逐渐富集成矿.%The Jincheng gold deposit lies in the north of Tongbai-Dabie orogenic belt in the Lu-oshan County of the Henan Province. Ore bodies of veins and lens are controlled by ductile shear zone,and are hosted by metamorphic rocks of upper Proterozoic Huwangang Formation. In accordance with paragenetic association of minerals and intercalation relationship of different veins, hydrothermal ore-forming period can be divided into 3 stages, quartz-gold-pyrite stage, quartz-polymetallic sulfides stage and quartz-carbonate stage respectively. Based on the geological setting ore formation and the geologic feature of deposit,we further investigate the fluid inclusions in the quartz and the fluorite of each ore-forming stage as well as the oxygen and hydrogen isotope composition of the quartz are studied. It shows that the ore-forming of the gold deposit is characterized by medium to low temperature,medium to low salinity and low density system. The S18O

  4. Experimental Study on Gold Ore with Clay-bearing Mineral%含泥质矿物的金矿石浮选试验研究



    对某金矿石进行的浮选试验研究结果表明,含金黄铁矿中泥质矿物是影响金选矿工艺指标的主要因素,在强化载金黄铁矿浮选的同时,选择合理的调整剂可以显著的提高金的选矿工艺指标。经过试验研究,在原矿含金品位为2.53 g/t时,浮选获得了金精矿含金品位为62.50g/t ,金回收率为92.60%的工艺指标。新型复合捕收剂sk和调整剂羧甲基纤维素的应用是提高精矿含金品位的关键。%An experimental study result of a kind of gold ore shows that the main factor affecting the miner-al flotation process index is the clay mineral in gold-bearing pyrite . At the same time of strengthening flo-tation of gold loaded pyrite , choosing a reasonable adjustment can significantly increase the mineral flota-tion process index . Through experimental study , when the gold grade of a raw ore is 2 .53 g/t ,the better process indexes have gain by flotation :the grade of gold-bearing gold concentrates is 62 .50 g/t , and the gold recovery is 92 .60% .The application of new type composite collectors sk and regulator carboxymeth-ylcellulose is the key to increase the gold concentrate grade .

  5. Research on gold extraction from a carlin-type oxide gold ore in Gansu%甘肃某卡林型氧化金矿石回收金试验研究

    缑明亮; 崔长征


    甘肃某卡林型氧化金矿石中金以微细粒包裹赋存在硫化矿、氧化铁矿、碳酸盐、硅酸盐等矿物中,采用全泥氰化和浮选工艺处理,金回收率很低.通过探索试验,确定采用焙烧—氰化工艺处理,在试验确定的最优条件下,金氰化浸出率可达到92%,取得了理想试验指标.%Oxide gold ores in this carlin-type gold deposit in Gansu province occur in superfine form embeded in sulfide ores,ferrous oxide ores,carbonate,silicate and so on.Poor gold recovery is only to be achieved when all sliming cyanidation and flotation are applied.Through exploratory experiments,a process of roasting-cyanidation is selected,in which,under optimisedconditions,gold recovery can reach 92 %.


    高太忠; 赵伦山; 杨敏之


    山东牟乳金矿带位于华北地台东缘活化区。区内荆山群和胶东群变质绿岩建造是金矿化的矿源层。区内主要控矿构造为北北东、北东向构造。金矿床主要为含金硫化物石英脉型。成矿流体来源于地壳深部和后期大气降水的加入。对矿带成矿演化机理的研究表明,金矿形成经历了 3个阶段:①新太古至古、中元古代金初始矿源层形成阶段;②中元古代末期区域变质—混合岩化金再富集阶段和③燕山期构造—流体—金成矿作用阶段。%The Mouping- Rushan gold ore belt lies in the activated region on the eastern margin of the North China Craton.The Jingshan and Jiaodong Groups metamorphic green formation is the source bed of the gold mineralization in this region.The main controlling structures are the NNE,and NE - trending faults.Gold ore main type is auriferous quartz vein type.Ore- forming fluid rooted in the deep crust mixed with meteoric water.The research for metallogenic evolution mechanism in the region indicates that gold ore formation has undergone three stages:① gold elementary source bed formation stage from the Neo- Archean to the Paleo- Proterozoic and Meso- Proterozoic,② regional metamorphism- migmatization gold reenrichment stage at the late Meso- Proterozoic,③ structure- fluid- gold mineralization stage at the Yanshan Period.

  7. The Sarylakh and Sentachan gold-antimony deposits, Sakha-Yakutia: A case of combined mesothermal gold-quartz and epithermal stibnite ores

    Bortnikov, N. S.; Gamynin, G. N.; Vikent'eva, O. V.; Prokof'ev, V. Yu.; Prokop'ev, A. V.


    New mineralogical, thermobarometric, isotopic, and geochemical data provide evidence for long and complex formation history of the Sarylakh and Sentachan Au-Sb deposits conditioned by regional geodynamics and various types of ore mineralization, differing in age and source of ore matter combined in the same ore-localizing structural units. The deposits are situated in the Taryn metallogenic zone of the East Yakutian metallogenic belt in the central Verkhoyansk-Kolyma Fold Region. They are controlled by the regional Adycha-Taryn Fault Zone that separates the Kular-Nera Terrane and the western part of the Verkhoyansk Fold-Thrust Belt. The fault extends along the strike of the northwest-trending linear folds and is deep-rooted and repeatedly reactivated. The orebodies are mineralized crush zones accompanied by sulfidated (up to 100 m wide) quartz-sericite metasomatic rocks and replacing dickite-pyrophyllite alteration near stibnite veinlets. Two stages of low-sulfide gold-quartz and stibnite mineralization are distinguished. The formation conditions of the early milk white quartz in orebodies with stibnite mineralization at the Sarylakh and Sentachan deposits are similar: temperature interval 340-280°C, salt concentration in fluids 6.8-1.6 wt % NaCl equiv, fluid pressure 3430-1050 bar, and sodic bicarbonate fluid composition. The ranges of fluid salinity overlapped at both deposits. In the late regenerated quartz that attends stibnite mineralization, fluid inclusions contain an aqueous solution with salinity of 3.2 wt % NaCl equiv and are homogenized into liquid at 304-189°C. Syngenetic gas inclusions contain nitrogen 0.19 g/cm3 in density. The pressure of 300 bar is estimated at 189°C. The composition of the captured fluid is characterized as K-Ca bicarbonatesulfate. The sulfur isotopic composition has been analyzed in pyrite and arsenopyrite from ore and metasomatic zones, as well as in coarse-, medium-, and fine-grained stibnite varieties subjected to

  8. 哈西亚图金矿选矿综合回收利用研究%Research on Comprehensive Recovery and Utilization of Gold Ore in Haxiyatu

    代岩; 刘江峰; 朱建鹏


    The gold ore associated in Haxiyatu iron-polymetallic deposit has reached medium-scale,which can greatly improve the economic efficiency of the iron-polymetallic deposit.Research on comprehensive recovery and utilization method of gold ore is very important.The gold ore belongs to the sulfide skarn type,with the natural type belonging to the mixed ore.The metal minerals in the ore are dominated by magnetite,pyrrhotite and pyrite,and noble metal minerals are native gold and electrum.Through the experiment,the flotation process scheme is recommended that“gold flotation,tailings magnetic iron and iron concentrate flotation sulfur”.Leaching process scheme is recommended that“all sliming cyanidation carbon leaching,tailings magnetic separation iron and iron concentrate flotation sulfur”.According to the test results,the process by all sliming cyanidation carbon leaching and magnetic iron(remove sulfur by floating) can obtain better effect.%哈西亚图铁多金属矿床中共生的金矿规模已达中型,可大大提高该矿床的经济效益,对金矿综合回收利用方法的研究显得尤为重要。矿石工艺类型为中硫化物矽卡岩型金矿石,矿石自然类型属混合矿。矿石中主要金属矿物为磁铁矿、磁黄铁矿和黄铁矿,贵金属矿物为自然金和银金矿。通过试验研究,浮选工艺推荐“浮选金—尾矿磁选铁—铁精矿浮硫”方案,浸出工艺推荐“全泥氰化炭浸提金—尾渣磁选铁—铁精矿浮硫”方案。试验结果表明,采用全泥氰化炭浸—磁选铁(浮选除硫)工艺处理哈西亚图金矿石效果最佳。

  9. Dissolution of Gold and Silver with Ammonium Thiosulfate from Mangano-Argentiferous Ores Treated in Acid-Reductive Conditions

    Tiburcio Munive, G.; Encinas Romero, M. A.; Vazquez, V. M.; Valenzuela García, J. L.; Valenzuela Soto, A.; Coronado Lopez, J. H.


    A novel process was studied to extract economic metals from refractory ores that are difficult to leach with cyanide and ammonium thiosulfate, such as the well-known mangano argentiferous minerals, which are minerals of manganese, iron, and silver. The mineral under consideration originates from the tailings of the Monte del Favor, Hostotipaquillo Jalisco, Mexico. The sample was characterized by x-ray diffractometry, atomic absorption spectroscopy, scanning electron microscopy, and microanalysis by energy-dispersive x-ray spectroscopy. First, the material was passed through a 100-mesh screen, and then it was subjected to reductive leaching by varying the liquid-solid ( L/ S) ratio from 2:1 to 10:1 (observations were carried out at a ratio of 5:1, which yielded higher extraction of manganese). With H2SO4 and Na2SO3 as the reducing agents, manganese extraction of up to 96.05% was achieved during the first 3 h with a mineral head of manganese 3.58%, acid consumption of 90.74 g/L, and sulfite consumption of 25.8 g/L. The mineral was then filtered and proceeded to neutralize the acidity, reaching a pH of 8 with calcium hydroxide. Then, the material was subjected to a new leaching of gold and silver values with ammonium thiosulfate. The L/ S ratio was varied (1:1, 2:1, 3:1, 4:1), and the contact time and the concentration of ammonium thiosulfate was investigated, while controlling the pH using Ca(OH)2 and NH4Cl. An L/ S ratio of 2:1 showed the best extraction of silver (97.06%) and gold (86.66%), and the thiosulfate consumption was 10.36 g/L. The mineral head of gold and silver was 0.30 g/ton and 310 g/ton, respectively. The pH was maintained between 9.8 and 8.4, such that ammonium thiosulfate stabilized with lime, and ammonium chloride did not suffer any decomposition.

  10. The Isotopic Composition of Noble Gases in Gold Deposits and the Source of Ore-Forming Materials in the Region of North Hebei,China

    王宝德; 牛树银; 孙爱群; 李红阳


    The source of ore-forming materials has long been a controversial focus both in metallogenic theory and in ore-searching practice. This study deals with the helium and argon isotopic characteristics of pyrites from 11 gold deposits and some country rocks in the gold mineralizationconcentrated areas within the three mantle-branch structures in the region of North Hebei Province. It is indicated that 3He/4He ratios in the gold deposits are within the range of 0.93 × 10 -6-7.3×10-6,with an average of 3.55 × 10-6; R/Ra =0.66 -4.93,averaging 2.53;40Ar/39Ar ratios vary between 426 and 2073,with the average value of 40Ar being 8.32; and the average of 4He/40Ar ratios is 2.17. 3He/4He ratios in gneiss and granite in the periphery of the mining district are within the range of 0. 001 × 10 -6 _ 0. 55 × 10 -6,reflecting significant differences in their sources. 3 He and 4 He fall near the mantle,as is shown in the He concentration diagram. Studies have shown that the ore-forming materials in this region should come from the deep interior of the Earth. With the multi-stage evolution of mantle plume,ore-forming fluids in the deep interior were moving upwards to shallow levels (crust). Under such circumstances,there would be inevitably occur crust/mantle fluid mixing,so their noble gas isotopic characteristics are intermediate between the mantle and the crust.

  11. Minimum critical thickness of dike for ore-bearing fluid injection: A new approach applied to the Shihu gold deposit, Hebei Province, North China

    Dedong Li


    Full Text Available According to the metallogenic theory by transmagmatic fluid (TMF, one magmatic intrusion is a channel of ore-bearing fluids, but not their source. Therefore, it is possible to use TMF’s ability for injection into and for escaping from the magmatic intrusion to evaluate its ore-forming potential. As the ore-bearing fluids cannot effectively inject into the magmatic intrusion when the magma fully crystallized, the cooling time and rates viscosity varied can be used to estimate the minimum critical thickness of the intrusion. One dimensional heat transfer model is used to determine the cooling time for three representative dikes of different composition (granite porphyry, quartz diorite and diabase in the Shihu gold deposit. It also estimated the rates viscosity varied in these time interval. We took the thickness of dike at the intersection of the cooling time – thickness curve and the rates viscosity varied versus thickness curve as the minimum critical thickness. For the ore-bearing fluids effectively injecting into the magma, the minimum critical thicknesses for the three representative dikes are 33.45 m for granite porphyry, 8.22 m for quartz diorite and 1.02 m for diabase, indicating that ore-bearing dikes must be thicker than each value. These results are consistent with the occurrence of ore bodies, and thus they could be applied in practice. Based on the statistical relationship between the length and the width of dikes, these critical thicknesses are used to compute critical areas: 0.0003–0.0016 km2 for diabase, 0.014–0.068 km2 for quartz diorite and 0.011–0.034 km2 for granite porphyry. This implies that ore-bearing minor intrusions have varied areas corresponding to their composition. The numerical simulation has provided the theoretical threshold of exposed thickness and area of the ore-bearing intrusion. These values can be used to determine the ore-forming potentials of dikes.


    张连昌; 沈远超; 曾庆栋; 邹为雷


    邓格庄金矿床位于胶东牟平-乳山金矿带的北段,含金石英脉受NNE向断裂控制。工业矿体由矿化石英脉的富金段组成。富金矿体在走向上一般分布于NNE向断裂的转折地段,倾向上分布于断裂产状由陡变缓的过渡部位。控矿构造经历了压剪性到张剪性的演化过程,主要成矿作用发生于断裂的张剪性活动阶段。深部地质地球化学研究表明,Ⅱ号矿体深部还有隐伏矿体存在。%Denggezhuang gold deposit is located in north of Muping-Rushan gold ore belt. The occurrence of gold-bearing quartz vein was controlled by NNE-trending faulted zones. The ore-body is in the gold-rich part of ore-bearing quartz vein. The gold-rich ore bodies occurrs in the winding part of NNE-trending fractures on strike and transforming part from steeply dipping to gently dipping on dip direction. The ore-controlling faults underwent a evolutional process from compressional shearing to tensional shearing and the main ore-forming process took place in the stage of tensional shearing. Studies on the primary geochemical halo from the deep of Denggezhuang gold deposit shows that the vein No.II has characteristics of reversed axial zonality. The authors considered that there should be blind ore-body under the ore-body No.II.

  13. Flotation Experiment Research on A Gold ore of a Gold Mine from Inner Mongolia%内蒙古某金矿石金的浮选试验研究

    程秀峰; 周南


    The main recovering element in a ore is gold , and gold mineral is micro particle . poisonous ele-ment in a ore is less . The technology of one coarse grinding and two roughing flotation Followed by three cleanings .This technology is simple and effective . Flotation gold concentrate grade is 122 g/t and the gold recovery rate 92 .56% on the condition of crude gold grade being 19 .56g/t . This technological process pro-vides a technical basis for the development of the mine .%矿石中可回收的元素为金 ,属于微细粒金 ,有害元素砷含量较低.浮选工艺流程为一次粗磨两次粗选、三次精选.工艺流程简单有效 ,在原矿品位A u4 .20 g/t条件下 ,浮选得到金精矿金品位122 g/t ;金回收率92 .56% .为该金矿的合理开发提供了技术依据.

  14. Chemical and stable isotopic geochemical characteristics of ore-forming fluid of the Shizishan copper and gold ore-field, Tongling, China%铜陵狮子山铜金矿田成矿流体成分及稳定同位素地球化学

    陆三明; 徐晓春; 谢巧勤; 楼金伟; 储国正; 熊亚平


    Shizishan ore-field is a nonferrous and noble metal ore-field which is most rich in copper and gold. There are many types of fluid inclusions in minerals of the deposits. The homogeneous temperatures and the salinities of the fluid inclusions in main mineralization stages have wide ranges, while the different types of the fluid inclusions existed together and their homogeneous temperatures are almost identical in the same mineralization stage, which indicates that the ore-forming process has great relation with the fluid boiling. The gas and liquid chemical compositions and the carbon, hydrogen and oxygen isotopic compositions of the fluid inclusions show that the ore-forming fluids of copper-gold deposits have the same characteristics and evolution tendency, which reflects that the ore-forming material mainly came from the magmatism. The stratigraphic component and the meteoric water may mix in oreforming fluids in the later mineralization stages. Furthermore, with the fall of the ore-forming temperature the ratios of water and rock decreased. The characteristics of chemical composition and carbon isotopic composition of fluid inclusions indicate that CH4 may play an important role for separating copper and gold in the ore-forming process.

  15. Discussion on grades of raw ores and raw ores for cyanidation in ore-dressing plant of Longtoushan Gold Mine%龙头山金矿选矿厂原矿品位、氰原品位问题探讨

    姚让彪; 林取乾


    针对贵港市金地矿业有限责任公司龙头山金矿选矿厂重选+氰化工艺流程因存在粗粒明金、矿样代表性差、部分金提前浸出,导致原矿品位、氰原品位实际值与理论值存在误差,金属难以平衡的问题。通过改进措施、选取合适的取样点,确定了一种较为合理的计算方法,使其实际值与理论值基本相符。%There are many defects in gravity separation -cyanidation process currently used in ore-dressing plant of Longtoushan Gold Mine,Guigang Jindi mining company,that are the presence of coarse-grained visible gold,poor representativeness of samples and early leached gold ,making the actual value of the grades of raw ores and raw ores for cyanidation deviate from the theoretical one and resulting in the imbalance between metal .To deal with that ,optimiza-tion measures are taken ,proper sampling sites are selected and thus a fairly reasonable calculation method is obtained , making the actual value of the grades consistent with the theoretical one .

  16. 锰银矿与含砷金矿同时浸出过程探讨%Simultaneous Leaching of Mn-containing Silver Ore andAs-containing Gold Ore

    袁明亮; 陈可; 邱冠周


    As-containing gold ore and Mn-containing silver ore were leachedsimultaneously by sulphuric acid to resolve FeAsS and MnO2.FeAsS and MnO2 can act as reductant and oxidant to each other, andthe co-leaching technique reduces the leaching cost. The experiments showedthat the resolution rate of MnO2 and FsAsO were 96% and 92%respectively, and the leaching rate of silver and gold were 85.4% and93.5% respectively, under the condition of using small amoumt ofwater-soluble oxidant. The overall recovery rate of gold and silver are93% and 84.5% respectively.%在硫酸体系中用两矿工艺同时浸出含砷金矿和锰银矿,以分解包裹金、银的毒砂和氧化锰矿物.由于毒砂和氧化锰可互为还原剂和氧化剂,因此该工艺降低了贵金属矿的预处理消耗.实验表明,在使用少量水溶性氧化剂NaClO3的条件下,氧化锰、毒砂分解率分别为96%和92%,银、金的浸出率分别可达85.4%和93.5%,总回收率分别为84.5%和93%.

  17. Mineral types of hydrothermal alteration zones in the Dukat ore field and their relationships to leucogranite and epithermal gold-silver ore, northeastern Russia

    Filimonova, L. G.; Trubkin, N. V.; Chugaev, A. V.


    The paper considers the localization of potassic and propylitic hydrothermal alteration zones in the domal volcanic-plutonic structure controlling the position of the Dukat ore field with the eponymous unique epithermal Au-Ag deposit. Comprehensive mineralogical and geochemical data on rocks and minerals in hydrothermal alteration zones and associated intrusions have shown that quartz-jarosite-sericite, quartz-pyrite-sericite, and quartz-adularia-chlorite alterations were formed with the participation of fluid flows related to a fingerlike projection of a high-K leucogranite porphyry intrusion with large phenocrysts. These hydrothermal alterations developed in the rifted graben under conditions of divergent plate boundaries, whereas quartz-clinozoisite-calcite, epidote-chlorite, and garnet-calcite-chlorite alterations were linked to K-Na leucogranite intrusive bodies and developed under conditions of convergent plate boundaries reactivated as a result of formation of the marginal Okhotsk-Chukotka volcanic belt. Phase separation and coagulation of specific portions of ascending fluids resulted in the formation and stabilization of small-sized particles of native silver and other ore components, which enabled involvement in flows of secondary geothermal solutions and ore-forming fluids. The Sr, Nd, and Pb isotopic compositions of rocks and minerals from the hydrothermal alteration zones, associated intrusions, and economic orebodies at the Dukat deposit indicate that their components have been derived from the juvenile continental crust, which was altered in pre-Cretaceous periods of endogenic activity. The components of gangue minerals of potassic and propylitic hydrothertmal alterations and associated intrusions have been taken from deep sources differing in 87Sr/86Sr and 143Nd/144Nd at similar U/Pb and Th/Pb ratios. Chalcophile lead in products of hydrothermal activity and melanocratic inclusions in leucogranite has been taken from regions with elevated U/Pb and

  18. A rapid fire-assay/atomic-absorption method for the determination of platinum, palladium and gold in ores and concentrates: A modification of the tin-collection scheme.

    Moloughney, P E; Faye, G H


    The tin-collection scheme of fire-assaying has been simplified to permit the rapid and accurate determination of platinum, palladium and gold in ores and related materials. The presence of tellurium in the charge ensures that the precious metals remain insoluble during the parting of the tin button with hydrochloric acid. The residue is easily collected and dissolved and the resultant solution analysed for the precious metals by AAS. The accuracy of the method has been established by application to five diverse certified reference materials.

  19. Study on gold extraction from double refractory gold ores with high sulfide and carbon content%高硫高碳双重难处理金矿石提金工艺研究

    石吉友; 赵喜民


    针对某高硫高碳双重难处理金矿石,采用常规浮选法、全泥氰化炭浆法和全泥氰化炭浸法进行处理,金浸出率均很低。最终,通过采用钝化-全泥氰化炭浸工艺处理该矿石,获得了较好指标,金浸出率达到82.83%。%Gold leaching rates are frustrating when conventional flotation ,all-sliming cyanidation-CIP and all-sli-ming cyanidation-CIL method are applied in the treatment of some double refractory gold ores with high sulfide and carbon content.Finally,an inactivation -all-sliming cyanidation-CIL process is used,achieving better indexes with gold leaching rate reaching 82.83 %.

  20. 从含碳金矿石中提金工艺方法的试验研究%Experimental Study on the Technique of Extracting Gold from Carbonaceous Gold Ore

    薛光; 于永江; 吴国富


    拟定了一种从含碳金矿石中提取金的工艺方法,该方法采用氨水-煤油混合体系对矿样进行预处理,从而使可溶性铜形成铜氨络合物,使矿样中的碳吸附煤油而钝化,以消除碳在氰化过程中对金的吸附。在助浸剂H2O2存在的条件下,分别采用CaO和NaOH为pH值的调整剂进行氰化浸出,使金的氰化浸出率分别达到96.01%和97.79%,具有较好的经济效益和社会效益。%One technique of extracting gold from carbonaceous gold ore has been intended,which pretreated ore samples using the ammonia-kerosene mixed system,and made soluble copper become to be copper ammonia complex.It enables the carbon in ore samples adsorbed kerosene and passivated,and eliminated the gold adsorption in carbon’s cyanide leaching process.In the presence of leaching aid(H2O2) and using CaO and NaOH as the pH value regulator respectively,the cyanide leaching rate of gold has reached 96.01% and 97.79%.There are good economic and social benefits.

  1. Failure inspiration of Mozambique gold ore investment%投资莫桑比克金矿失败的启示

    车海龙; 李波; 王冠中; 王雷; 孙冬雪


    In response to the“going out”strategy, a large-scale private enterprise to invest in Mozambique gold mine, although with many conditions, but in the end they did not ifnd industrial ore body for the scale mining. That brings the following enlightenments to us:(1) the data of Mozambique has low reliability;(2) placer gold spread all over the Africa, but there is not gold ore body;(3) use geochemical prospecting for gold, need to study the element zoning and denudation depth problem;(4) the prospecting work must be step by step, can not act with undue haste;(5) the geological prospecting is a high-tech industry, talents are the key to the success or failure of mining investment.%为了响应“走出去”战略,某大型民营企业投资莫桑比克金矿,虽然具备了很多条件,但是最终没有找到可供规模开采的工业矿体,给我们带来了以下几点启示:一是莫桑比克的资料可信度低;二是非洲大地砂金矿遍地,但是并非都有岩金矿体存在;三是利用化探找金,要研究元素分带和剥蚀深度的问题;四是找矿工作必须循序渐进,不能操之过急;五是地质找矿是高科技行业,人才是矿业投资成败的关键。

  2. Origin of ore-forming fluids of the Haigou gold deposit in the eastern Central Asian Orogenic belt, NE China: Constraints from H-O-He-Ar isotopes

    Zeng, Qingdong; He, Huaiyu; Zhu, Rixiang; Zhang, Song; Wang, Yongbin; Su, Fei


    The Haigou lode deposit contains 40 t of gold at an average grade of 3.5 g/t, and is one of the largest deposits in the Jiapigou gold belt located along the eastern segment of the northern margin of the North China Craton. The deposit comprises 15 gold-bearing quartz veins hosted in a Carboniferous monzonite-monzogranite stock. Cretaceous dikes consisting of diorite, diabase, and granodiorite porphyries are well developed in the deposit. The diorite porphyry dikes (130.4 ± 6.3 Ma) occur together with gold-bearing quartz veins in NNE- and NE-striking faults. Gold-bearing quartz veins crosscut the diorite porphyry dikes, and the veins are in turn crosscut by E-W-striking 124.6 ± 2.2 Ma granodiorite porphyry dikes. The mineralization mainly occurs as auriferous quartz veins with minor amounts of sulfide minerals, including pyrite, galena, chalcopyrite, and molybdenite. Gold occurs as either native gold or calaverite. Common gangue minerals in the deposit include quartz, sericite, and calcite. The deposit is characterized by various types of hydrothermal alteration, including silicification, sericitization, chloritization, potassic alteration, and carbonatization. Three stages of hydrothermal activity have been recognized in the deposit: (1) a barren quartz stage; (2) a polymetallic sulfide (gold) stage; (3) a calcite stage. Fluid inclusions in hydrothermal pyrites have 3He/4He ratios of 0.3 to 3.3 Ra and 40Ar/36Ar ratios of 351 to 1353, indicating mixing of fluids of mantle and crustal origin. Hydrothermal quartz yielded δ18O values of -1.3‰ to +7.2‰ and δD values of fluid inclusions in the quartz vary between -80‰ and -104‰. These stable isotope data also suggest mixing of magmatic and meteoric fluids. Noble gas and stable isotopic data suggest that the ore fluids have a predominant mantle source with a significant crustal component. Based on the spatial association of gold-bearing quartz veins with early Cretaceous intrusions, and the H-O-He-Ar isotopic

  3. 辽宁邵家堡子地区金成矿地质条件及找矿前景%Ore-search prospects, ore-forming geological conditions and gold mineraliza tionin in shao jia of liaoning province



    为了研究邵家堡子地区金及多金属矿的有利成矿区的成矿特征,通过对区域地质背景、区域地球物理、地球化学特征及成矿条件分析,研究表明:金矿化主要发育于燕山期侵入花岗岩体与鞍山群变质岩系接触部位的断裂构造中,燕山期构造运动和强烈的岩浆活动为成矿物质富集提供了充足的热源和赋矿空间,区域上形成了连续的金、铜等元素富集带,具备了矿集区的特征,具有良好的找矿前景.该研究对邵家堡子地区金及多金属矿的开发具有一定的参考价值和指导意义.%To study to main characteristics of gold mineralize tionin in the shaojia of liaoning province,Analysis of the geogical background, geophysical characterstics, geochemical characterstics and ore-forming conditions ,most investments showed that gold mineralization chiefly construeted in contact of Yanshannian granitic intrusions and metamorphic rock series of Anshan group, Yanshan construction movement and strong magma movement supply enougy energy and space for minerals.forming continuous such as gold, copper enrichment cincture, has the characters of mineral-gather, and has the good prospect for seeking mineral.The research has some instruction meaning and reference value to development in gold mineralize tionin in the shaojia of liaoning province.

  4. The Study of the Ore Character of Luoba Gold Deposit Gansu Province%甘肃省徽县洛坝金矿床矿石特征研究



    洛坝金矿床矿石工艺类型为贫硫化物全氧化含金矿石类型,矿石中金矿物为自然金及银金矿,有害元素炭品位为>0.1%,金矿物粒度细小,赋存状态以裂隙金为主,次为粒间金、包裹金;载金矿物主要为褐铁矿,粒度粗细不均,大部分粒度较细;通过对矿石质量研究,为选矿试验提供必要参数,并为矿床下步开发提供依据.%The technical types of the ore of the Luoba deposit is the gold ore types of poor sulfide and all oxidation, the gold mineral in the ore is gold and electrum, the content of Carbon as the deleterious element is above 0.1%, The gold mineral's granularity is exiguous, its beigng state is fissures at first, and then is intergranulars and entrainments; the mineral which carrying the gold element is limonite,it's granularity is asymmetrical, but exiguous in a great measure. By studying the ore quality, this article offered the necessary parameter for mill run and offered the gist for the exploitation of the deposit.

  5. 某氧化型金矿石氰化浸出试验%Experimental Research on Cyanide Leaching of an Oxidized Gold Ore

    王伟之; 韩苗苗


    某氧化型金矿石金含量高达7.76 g/t,但浮选工艺回收效果极不理想.采用分段浸出工艺对磨矿细度、氰化钠用量、浸出时间等重要工艺技术条件进行了研究,还对影响金浸出的铜离子进行了预处理研究.结果表明,浸前氨水预处理有利于削弱铜对金浸出的负面影响,在试验确定的最佳工艺技术条件下,金浸出率达到了90.11%,达到了工业生产要求.%An oxidized gold ore contains gold up to 7. 76 g/t,but the gold recovery is highly undesirable by adopting the flotation process. Tests on the technical conditions of grinding fineness, sodium cyanide consumption, leaching time through segment leaching process are carried out,by which Cu ions that affects the gold leaching are pre-treated. The test results show that the ammonia pretreatment before leaching is conductive to weaken the negative impact of copper on gold leaching. Under the optimum conditions obtained from the above tests,gold leaching rate reaches 90. 11% .which can meet the requirements of industrial production.

  6. 难处理含铜氧化金矿抑铜浸金试验研究%Study on Copper Inhibition-Gold Leaching from Copper-Bearing Gold Refractory Ore



    提出一种新型的选择性抑铜浸金新工艺处理含铜氧化金矿,该工艺加入抑浸剂(MZY)后进行氰化浸出,可达到抑铜浸金的效果,并对工艺参数进行优化.结果表明,当石灰、MZY和氰化钠用量分别为18、0.5和1.2 kg/t时,金、铜浸出率分别为83%~84%和4%~5%,新工艺的金浸出率高、铜抑制效果好、操作简单.%Abstract:A new process to leach gold from copper-bearing gold refractory ore was put forward.Copper was inhibited with depressant (MZY) and gold was selectively cyaniding leached.The technical parameters were optimized.The results show that the leaching rate of gold and copper is 83 %~84% and 4%~5 % respectively when the dosage of lime,MZY and sodium cyanide is 18,0.5 and 1.2 kg/t respectively.The new process has the advantages of high gold leaching rate,good copper inhibitory effect,and easy operation.


    魏明安; 张锐敏


    利用微波的加热特性,通过条件试验确定,在450℃用微波处理5min,可使某金矿的金精矿氰化浸出率由74%提高到90%以上,使现场金精矿氰化渣的氰化浸出率达到86%以上。试验结果表明,微波预处理对于打开黄铁矿包裹金的前景光明。%By using the heating feature of microwave, it has shown from condition tests that the gold leaching recovery can be improved from 74% to more than 90% if the gold concentrates is treated for 5 minutes in a microwave oven at 450℃. Therefore, the gold leaching recovery of cyanide residue of more than 86% can be obtained in leaching plant. The results indicate that microwave pretreatment to packaged gold by pyrite in gold ores has a glory prospect.

  8. Element Geochemistry and Petrogenesis of High—K Potassic Dike Rocks in Two Types of Gold Ore Fields in Northwest Jiaodong,Shandong,China

    孙景贵; 叶瑛; 等


    This paper deals with the high-K,potassic dike rocks in two types of gold ore fields at Linglong and Dayigezhuang,Northwest Jiaodong.The rocks can be divided into three types.i.e.,(1) lamprophyre,(2) andesite porphyrite,and (3) dacite porphyrite,based on their geological occurrence and space-time relationship with gold mineralization.These rocks were the products of early,synchronous and late mineralization.respectively,Element geochemistry shows that variations in chemical composition of major oxides follow the general rules of magmatic fractional crystallization.The fractional crystallization of mineral phases of augite in the early stage(namely in the lamprophyre stage)and hornblende and plagioclase in the late stge(namely from the andesite-porphyrite to dacite porphyrite stage)controlled the magma evolution.The rocks are enriched in alkili and have higher K2O and lower TiO2 contents,as well as strongly enriched in large ion lithophile elements such as Ba,Sr and Rb,and LREE but strongly depleted in transition elements such as Cr and Ni,Rb is depleted relative to Sr and Ba,and Rb/Sr ratios are low.Volatile constituents are abundant.These characteristics indicate that the initial magma originated from the metamorphic subduction ocean-crust that had been intensively contaminated by crustal materials,and retrogressive metamorphism is characterized by low-degree partial melting during back-arc spreading,Varying degrees of partial melting and different emplacement enviornments may be the main causes for the evolution of the rocks and mineralization in different degrees in the two gold ore fields at Linglong and Dayigezhuang,Shandong.

  9. Experimental research on one refractory gold ore in Hebei%河北某难选金矿选矿试验研究

    唐平宇; 郭秀平; 王素; 李龙飞; 高璐


    针对河北某金矿矿石自然金粒度大小不等、嵌存状态复杂的特点,采用尼尔森重选-浮选工艺流程回收金取得了较为理想的指标。尼尔森选矿机处理一段磨矿产品回收中粗粒金,获得品位291 g/t、回收率26.71%的重选金精矿。尼尔森中矿并入尾矿一起再磨至-0.074 mm占85%,以丁基黄药和M-钠盐组合捕收剂强化金的浮选,获得品位122.7 g/t、回收率62.35%的浮选金精矿,金总回收率达到89.06%。相比单一浮选流程,金回收率提高3.57%。%Considering the characteristics of different sized native gold and complex embedding conditions of one gold ore,Nelson gravity-flotation process is used to recover gold and achieves satisfactory results .Nelson processing machinery treats the first-stage grinding products and recovers medium and large sized gold particles ,obtaining gravity separation gold concentrates with grade of 291 g/t and recovery rate of 26.71 %.Nelson middlings are mixed with tailings and together grinded to 85 % -0.074 mm.Combined collector of Butyl Xanthate and M-sodium salt is used to enhance gold flotation,obtaining flotation gold concentrates with grade of 122.7 g/t and recovery rate of 62.35%. Overall gold recovery rate reaches 89.06%and compared to single flotation process ,gold recovery rate is increased by 3 .57 %.

  10. Heap Leaching Test for a Low Grade Gold Ore in He'nan%河南某低品位金矿堆浸试验研究

    曹飞; 吕良; 李文军; 岳铁兵


    河南某金矿为低品位高泥质氧化金矿,金含量0.98 g/t,实验室采用柱浸工艺模拟现场堆浸进行试验研究,通过对矿石粒度、氧化钙用量、喷淋液氰化钠浓度、浸出时间等工艺参数进行优化,确定了最佳条件,并获得了较好的选别指标,金浸出率89.23%,浸渣金品位0.11 g/t。如原矿含泥较高,则可进行分级处理,分级后粗级别采用堆浸工艺,细级别则采用搅拌浸出工艺。试验所采用的工艺为处理同类型金矿提供了强有力的技术支撑。%A high politic, low grade oxidized gold ore in He'nan contains 0.98 g/t of Au.Labora-tory test was conducted by the column leaching , which can simulate heap leaching process .The processing parameters , including ore granularity , calcium oxide dosage ,spraying liquid -sodium cyanide concentration and leaching time , were optimized and the best result was obtained .The fi-nal leaching rate was 89.23%and the gold content of the leaching residues was 0.11 g/t.When the slime content goes high in the run -of-mine, classification is recommended before leaching process .In this case, the coarse size can go to heap leaching while agitation leaching is more suit -able for the undersize particles .The study can be a reference for exploitation of similar gold ore.

  11. Metallogenetic Prediction Based on an Ore-Prospecting Model:An Application of QI Ⅰ Gold Deposit Prospecting Model%基于找矿模型的成矿预测——以齐Ⅰ金矿为例

    曾祥武; 刘家军; 赖月荣; 刘雪刚


    安齐成矿带是新疆重要金成矿带,齐Ⅰ金矿是该成矿带目前发现的最大金矿床.对比齐Ⅰ金矿找矿模型,结合遥感解译成果,在周边地区应用地质、物探、化探、遥感等找矿方法进行成矿预测,圈定出多处找矿靶区,经工程验证,发现工业矿体.利用找矿模型以现有资料为基础,以有效勘查方法组合为手段,设计验证工程,指导找矿勘探工作.%The QI I gold deposit is the biggest gold deposit metallogenic belt in anqi,one of the most important gold deposits in XinJiang.In order to enhance geological research and summarize the results of previous survey to guide the later prospecting work,we make comparison with the QI I gold prospecting model and use the remote sensing information to analyze the conditions of mineral formation in this area. Based on QI I ore-prospecting model,we successfully applied a set of effective working methods which integrate geology,geophysics,geochemistry and remote sensing to locate the target ore area quickly around QI I gold deposit. Located some target ore areas,with Au,Ag,As anomaly.Anomaly inspection led to the discovery of the new ore-body,which shows that target selection was fairly successful.On the basis of the prospecting model and comprehensive analysis of the resource potentials scientific resource prospecting plan is put forward and performed,with the ore body in depth being the main exploratory target.

  12. Up-dated ore composition data (Central ore-field, Kuznetsk Alatau

    Bushmanov A.


    Full Text Available Applying scanning electron microscope (SEM, energy-dispersive microanalyzer and X-ray ray fluorescence microscope the ore mineral composition in Central gold-ore field ore field (Kuznetsk Alatau was investigated. Eleven new minerals were detected in this ore field. The differentiated behavior of mineral formation stages in veinsand near-veined beresites was determined. The composition of native gold was studied, as well as the distribution of trace elements in pyrite.

  13. Gold and Antimony Mixed Flotation on a Micrite Gold Antimony ore in Guizhou%贵州某泥晶灰岩型含锑金矿金锑混浮试验

    石贵明; 周意超


    贵州某泥晶灰岩型含锑金矿石为块状构造,金属矿物主要为黄铁矿、针铁矿,含量小于1%,非金属矿物以方解石为主,另有少量石英、有机质等;金含量为6.04 g/t,显微镜下未见自然金粒,74.34%的金赋存在硫化矿中,游离金仅占总金的7.14%;硅酸盐、碳酸盐包裹金分别占11.96%和6.56%;锑主要以辉锑矿的形式存在。为高效、低成本回收矿石中的金、锑,对混合浮选工艺进行了试验研究。结果表明,在一段磨矿细度为-0.074 mm占71%的情况下1粗2扫混浮、尾矿再磨细度为-0.074 mm占92.7%的情况下再1粗2扫混浮、两粗精矿合并后3次精选、中矿顺序返回流程处理,最终获得了金品位为47.60 g/t、锑品位为9.81%、金回收率为76.68%、锑回收率为85.22%的金锑混合精矿,金锑混浮效果较理想。尾矿中金的回收及金锑分离工艺研究将另文介绍。%The micrite type antimony-containing gold ore in Guizhou is in blocky construction. Its metallic minerals are mainly pyrite and goethite,with content of less than 1%. Non-metallic minerals are calcite,and few of quartz,organic matter, etc. It contains gold of 6. 04 g/t,and natural gold grains were not seen in microscope,74. 34% of the gold occurred in sulfide ore,free gold accounted for only 7. 14%,wrapped gold in silicate and carbonate accounted for 11. 96% and 6. 56% respective-ly. Antimony mainly existed in the form of stibnite. Bulk flotation process was studied to make high efficient recovery of gold and antimony at low costs. The results indicated that,at the grinding fineness of 71% passing 0. 074 mm,through one roughing and two scavenging bulk flotation,one roughing and two scavenging bulk flotation after regrinding the tailings to 92. 7% passing 0. 074 mm,three cleaning flotation for the two mixed rough concentrate,and then middles back to the flow-sheet in turn,rough gold-antimony concentrate with gold grade of 47. 60 g

  14. Experimental research on comprehensive recovery of a refractory gold ore%某难选金矿综合回收试验研究

    刘新刚; 宋翔宇; 翟晓辰


    某难选金矿矿石中伴生有铜、铁等有价元素,为了充分利用矿产资源,对该矿石进行了选矿综合回收试验研究。其结果表明:通过采用活化剂 AS -2活化浮选铜、浮选尾矿细磨预处理—氰化浸金工艺,可获得铜品位14.32%、回收率58.64%的铜精矿,金总回收率达到83.12%;氰化尾矿采用磁选回收磁铁矿并浮选脱硫,可得到铁品位62%以上的磁铁矿精粉和硫品位28%以上的硫铁矿精粉。该工艺流程有效地回收了矿石中的有价金属元素。%The experimental research on comprehensive recovery of gold,copper and ferrum from a refractory gold ore is performed to make full use of resources.Experimental results show that the copper concentrate with the recovery of 58.64 % and the grade of 14.32 % can be produced when reagent AS -2 was used as activators;in this circum-stance,flotation tailings were further processed by using fine grinding pretreatment -cyanidation process,total gold re-covery rate reached 83.12 %;Magnetic separation was used to recover magnetite from cyanide tailings,and flotation was used for removing pyrrhotite from magnetite.Fe grade of magnetite concentrates was above 62 % and S grade of pyrrhotite concentrates was above 28 %,respectively.Thus,the valuable metallic elements of refractory gold ore are ef-fectively recycled.

  15. Experimental study on gold extraction from quartz vein type gold ores with low metal sulfide content%某石英脉型贫金属硫化物金矿选矿试验研究



    Accoding to the characteristics of cataclastic albitite quartz vein type gold ores with low metal sulfide content ,an once grinding ( 70 %-0 .074 mm ) -once roughing -three times cleaning -three times scanvenging process is applied , obtaining satisfactory results , with a concentrate yield of 6.78 %, gold concentrate grade of 48.89 g/t,silver grade of 127.29 g/t,and gold recovery rate of 86.65 %,silver recovery rate of 71.50 %.%针对豫西某碎裂钠长岩石英脉型贫金属硫化物金矿石的矿石性质,进行了选矿试验研究。通过采用一段磨矿(磨矿细度-0.074 mm占70%)、一次粗选、三次精选、三次扫选浮选工艺流程,获得精矿产率6.78%,金品位48.89 g/t、银品位127.29 g/t,金回收率86.65%、银回收率71.50%的较好指标。

  16. 广西某微细粒浸染型金矿石提金试验研究%Experimental study on extraction of one ultra fine disseminated gold ore in Guangxi Province

    张勇; 任洪胜


    Experimental study on extraction of one ultra fine disseminated gold ore was conducted .The results show that with the crude ore grade of 12.00 g/t,the crude ore flotation-flotation tailings cyanidation process achieved a flotation concentrate grade of 41.30 g/t,gold recovery rate of 29.93%,gold leaching rate by flotation tailings cyani-dation of 71.24 %and the overall gold recovery rate of 79.85 %,indicating a satisfactory index.%  对广西某微细粒浸染型难处理金矿石进行了提金试验研究。其结果表明:在原矿金品位12.00 g/t时,采用原矿浮选—浮选尾矿氰化工艺流程,获得浮选精矿金品位41.30 g/t,金回收率29.93%,浮选尾矿氰化金浸出率71.24%,金总回收率为79.85%的较好指标。

  17. Fuzzy Comprehensive Appraisal of Concealed Ore Deposits


    In this paper, the transformation from the fuzzy to the accurate process is exemplified by the Jiaodong gold ore deposits concentrated region where the mathematical analysis is used to appraise and forecast regional concealed gold ore deposits. In this sense, this paper presents a new way to the appraisal of the non-traditional mineral resources.

  18. Magmatic-vapor expansion and the formation of high-sulfidation gold deposits: Structural controls on hydrothermal alteration and ore mineralization

    Berger, B.R.; Henley, R.W.


    High-sulfidation copper-gold lode deposits such as Chinkuashih, Taiwan, Lepanto, Philippines, and Goldfield, Nevada, formed within 1500. m of the paleosurface in volcanic terranes. All underwent an early stage of extensive advanced argillic silica-alunite alteration followed by an abrupt change to spatially much more restricted stages of fracture-controlled sulfide-sulfosalt mineral assemblages and gold-silver mineralization. The alteration as well as ore mineralization stages of these deposits were controlled by the dynamics and history of syn-hydrothermal faulting. At the Sulfate Stage, aggressive advanced argillic alteration and silicification were consequent on the in situ formation of acidic condensate from magmatic vapor as it expanded through secondary fracture networks alongside active faults. The reduction of permeability at this stage due to alteration decreased fluid flow to the surface, and progressively developed a barrier between magmatic-vapor expansion constrained by the active faults and peripheral hydrothermal activity dominated by hot-water flow. In conjunction with the increased rock strength resulting from alteration, subsequent fault-slip inversion in response to an increase in compressional stress generated new, highly permeable fractures localized by the embrittled, altered rock. The new fractures focused magmatic-vapor expansion with much lower heat loss so that condensation occurred. Sulfide Stage sulfosalt, sulfide, and gold-silver deposition then resulted from destabilization of vapor phase metal species due to vapor decompression through the new fracture array. The switch from sulfate to sulfide assemblages is, therefore, a logical consequence of changes in structural permeability due to the coupling of alteration and fracture dynamics rather than to changes in the chemistry of the fluid phase at its magmatic source. ?? 2010.

  19. Mineral processing test for a fine grain disseminated gold ore from Gansu Province%甘肃某细粒浸染型金矿石选矿试验研究

    靳建平; 向虹; 吴天骄; 万宏民; 齐晓东


    甘肃某细粒浸染型金矿石中金主要以包裹金形态存在,且载金矿物黄铁矿与脉石矿物连生关系复杂.针对该矿石的性质,进行了选矿试验研究.其结果表明:在最佳试验条件下,采用阶段磨矿-阶段浮选工艺,可获得金品位30.17 g/t、金回收率81.23%的较好指标;硫精矿经氧化焙烧—氰化浸出,金对原矿的回收率为6.96%,金总回收率达88.19%.%Mineral processing test was carried out for a fine grain disseminated gold ore from Gansu Province.The gold-carrying mineral is pyrite and it is connected with gangue minerals in a complex way.The test results under opti-mal test conditions,a stage grinding-stage flotation process can obtain a gold grade of 30.17 g/t and a gold recovery rate of 81.23 %.Sulfur concentrates go through roasting-cyanide leaching process,the recovery of primary gold ores is 6.96 %and the total recovery rate of gold is 88.19 %.

  20. 甘肃两当某高硫金矿石选矿试验研究%Beneficiation Experiment on a High Sulfur Gold Ore from Liangdang in Gansu Province

    宫在阳; 张飞飞; 马鹏程; 张志刚; 王文辉; 王路平


    There is 0.93 g/t gold in a high sulfur gold ore from Liangdang region in Gansu Prov-ince.76.71 % of the gold exists in form of packages and fissure gold in pyrite,fine disseminated,diffi-cult to be liberated.For fully recycling of gold in the ore,the flotation test research was conducted.Test results show that with Na2 S and Na2 SO3 as segmented sulfur inhibitor,CuSO4 as activator,butyl xanthate+ammonium butyl aerofloat as combination collector,via two roughing two scavenging-regrinding on the rough concentrate-four cleaning closed circuit separation process,gold concentrate with 20.74 g/t gold, 39.33% sulfur,gold recovery of 70.90%,tailings of 0.29 g/t gold was finally obtained,concentration of the gold was obtained,reduce the influence of sulfur on the gold concentrate quality.The test results provide technical basis for the determination of dressing process on the gold ore.%甘肃两当地区某高硫金矿石,金品位0.93 g/t,硫含量较高。76.71%的金以包裹金、裂隙金的形式嵌布在黄铁矿中,嵌布粒度细,单体解离困难。为充分回收利用矿石中的金,进行了浮选试验研究。试验结果表明,以 Na2 S 和 Na2 SO3分段抑制硫,CuSO4为活化剂,丁基黄药+丁基铵黑药为组合捕收剂,原矿经2粗2扫—粗精矿再磨—4次精选闭路试验选别,最终可获得金品位20.74 g/t、含硫39.33%,金回收率70.90%的金精矿,尾矿金含量仅0.29 g/t,实现了金的富集,降低了硫对金精矿质量的影响。选矿试验结果为该金矿石选别流程的最终确定提供技术依据。

  1. 某含铜氧化金矿石氨氰法浸金工艺试验研究%Study on gold extraction from an oxidized gold ore with copper by ammonia cyanide leaching



    Gold extraction was studied from a gold ore with copper by ammonia cyanide leaching in the paper as well as copper removal from pregnant solutions .The leaching results showed that in certain conditions ,satisfactory tech-nical indexes could be obtained ,with leaching residues grade of 0.38 g/t,average mass concentration of gold and copper in leaching pregnant solutions respectively are 2.27 mg/L and 61.94 mg/L,gold leaching rate according to residues is 89.44 %.Hydrogen peroxide is used for copper removal ,gaining a copper precipitation rate of 85.85 %,and copper grade in the oxidation precipitation slags is over 50 %,making it possible to sell them as copper concentrates .%针对某含铜金矿石进行了氨氰法浸金及浸出贵液脱铜试验研究。其结果表明:在一定条件下,可获得较好的技术指标,浸渣金品位0.38 g/t,浸出贵液金、铜平均质量浓度分别为2.27 mg/L、61.94 mg/L,渣计金浸出率为89.44%;采用双氧水除铜,铜沉淀率为85.85%,氧化沉淀渣铜品位超过50%,可以铜精矿出售。

  2. Research on the Flotation of a Gold - antimony Ore in Gansu%甘肃某金锑矿选矿试验研究



    The systematical flotation experiments were conducted on a gold - antimony ore in Gansu based on mineralogy. When the grinding fineness was 82% -0. 074 mm, sodium silicate was used as ganguefe depressant, lead nitrate as activator, and the mixture of sodium ethyl xanthate and ammonium dibutyl dithiophosphate as selective flotation collectors, an antimony concentrate of 50. 67% Sb could be obtained with a recovery of 78.43% . Then the mixture of sodium sulfide and copper sulfate were used as activators of gold - bearing mineral in antimony tailings, combined collectors was also used, and benzyl hydroxamic acid was used to enhance gold flotation. A gold concentrate containing 60. 89 g/t Au could be obtained with a recovery of 80. 52% .%以甘肃某金锑矿为研究对象,在矿石工艺矿物学研究的基础上,通过系统的浮选试验,对含锑0.73%、金2.42 g/t的原矿,确定在磨矿细度为-0.074 mm占82%时,采用单一的水玻璃作为脉石矿物抑制剂,以硝酸铅活化含锑矿物,混合使用乙基黄药和丁铵黑药优先浮选锑,组合采用硫化钠与硫酸铜活化浮锑尾矿中的载金矿物,混合使用Y89黄药和丁铵黑药浮金,浮金回路添加少量苯甲羟肟酸以强化浮选效果,实验室小型闭路试验可获得锑精矿品位50.67%、回收率78.43%;金精矿含金60.89 g/t、回收率80.52%的选矿指标.

  3. Developments in gold and silver recovery through flotation in processing of gold ore slags; Avances en la recuperacion de oro y plata mediante flotacion en escorias de procesamiento de menas de oro

    Hidalgo, N.; Diaz, A.; Bazan, V.; Sarquis, P.


    The aim of this work is to recover and improve the extraction of gold and silver present in smelting slags through various mineralogical processes applicable in gold ores. The slag was concentrated in a Knelson type centrifuge, two concentrates (C1 and C2 and a tailing T1) being obtained. In order to improve the recovery, three series of rougher flotation tests were conducted on the tailing T1. The variables analyzed were: particle size, type of collectors (xanthates, di-monothiophosphate) and flotation time. It was deduced that by applying gravity concentration, the recovery of Au and Ag (Knelson centrifuge) is 42.0% and 13.7%, respectively. Au recovery is improved by 87.7% through the flotation of the centrifuge separation tailings, whereas that for Ag is 47.4%. The optimum conditions were: particle size 200 mesh, collectors: PAX (15.8 g/t), F-C5439 (18.75 g/t), MIBC frother (12.5g/t) and 8.5 minutes of flotation time. (Author)

  4. Comparison determinations of gold in ore between atomic absorption spectrophotometry and hydroquinone volumetric method%原子吸收分光光度法与氢醌容量法测定矿石中金的比对



    Two kinds of analysis methods of gold in the ores are compared. The results show that, the atomic absorption spectrophotometry is better than the hydroquinone volumetric method.%本文对矿石中金的两种分析方法进行了比对。结果表明原子吸收分光光度法要优于氢醌容量法。

  5. Two series of copper-gold deposits in the middle and lower reaches of the Yangtze River area (MLYRA) and the hydrogen, oxygen, sulfur and lead isotopes of their ore-forming hydrothermal systems

    周涛发; 袁峰; 岳书仓; 赵勇


    Based on studies on the geological characteristics of the copper-gold deposits in the middle and lower reaches of the Yangtze River area (MLYRA) and their hydrogen, oxygen, sulfur and lead isotope compositions, it is concluded that there existed two series of copper-gold deposits. They are evolutional products of two ore-forming hydrothermal systems in different geodynamic settings and geological era. Series I is stratiform or stratabound copper-gold deposits. These deposits were formed by submarine exhalation and sedimentation of hydrothermal solutions in Her-cynian tensional tectonic environment after bot brine ascending along contemporaneous faults and exhaled into the sea-floor. Series II consists of copper-gold deposits related to medium and acidic magmatic intrusions. Their mineralizations took place in Yanshanian in a tensional or a transitional period to the tensional tectonic environment from the composite of the tethys tectonic regime and the Paleo-Pacific ocean tectonic regime, as well as in

  6. The Geological Characteristics and Deep Ore-searching Prospects of Gold Deposit in Yindongpo Tongbai, Henan Province%河南桐柏银洞坡金矿床特征及深部找矿前景

    王宗炜; 刘伟芳; 刘伟頡; 刘国范; 王勇


    The Henan Yindongpo gold deposit is situated in the conjunction area between the North China plate and yangtze plate, and is in the Tongbai-Dabieshan metallogenic sub-belt east of Qinling polymetallic mineralization belt. This tectonic line extends in NWW direction. The ore-deposit stratum is strictly controlled by Neoproterozoic Waitoushan Formation and ore-bearing structures. The ore deposit earth surface and shallow industry ore show saddle-shape and stratiform. As deep ore-searching going deep, it is found that gold ore does not disappear below former planned deep, besides it downward extend, and the gold ore become much thicker, grade higher, thus it shows a three layer floor metallogenic model.%河南省桐柏县银洞坡金矿床位于华北板块与扬子板块的接合部位、秦岭多金属成矿带东段桐柏—大别山成矿亚带内,区内构造线呈NWW向展布.矿床严格受新元古界歪头山岩组地层和赋矿构造双重因素控制.矿床地表及浅部主要工业矿体呈鞍状、似层状,分布在歪头山岩组厚层碳质绢云石英片岩内的朱庄背斜(形)转折端、倾伏端的虚脱部位中;随着深部找矿工作的进一步开展,发现原勘探深度标高以下,金矿体不但没有尖灭,反而向深部沿断裂呈似层状稳定延伸,金矿体厚度增大、品位增高,因而显示"三层楼"式成矿模式.扩大了找矿视野,为在该区寻找金多金属矿床开辟了广阔前景.




    With virtue of mild operation condition, faster oxidation velocity, lower invest cost and less pollution, refractory gold ore pre-oxidation by chemical reagent is a technique of good prospect. Nitric acid pre-oxidation, alkaline pre-oxidation, electrochemical intensive electrode and their industrial application are introduced respectively in the paper.%化学预氧化法指通过添加化学试剂的方式对矿石进行预氧化的技术,具有操作条件温和、氧化速度快、设备和生产投资费用较低、环境污染小等优点,在处理难浸金矿方面有很好的发展前景.本文分别介绍了硝酸预氧化法、碱性预氧化法和电化学强化电极法三种化学预氧化技术以及其在工业中的应用情况.

  8. Experimental study on Fioatation for a certain gold-silver ore containing lead in Jilin province%吉林省某矿含铅金银矿石浮选工艺试验研究

    郭宏; 邢洪波; 王学哲; 任洪胜


    Experimental study on floatation is carried out for a certain gold-silver ore containing lead in Jilin province.According to the low grade of gold, silver and lead, the experimental flowsheet is chosen as follow, raw ore bulk floatation-concentrate cyanidation-leaching residue floatation for lead.Ideal recovery rates are obtained as follow, gold 83.80 %, silver 51.19 % , lead 77.91% and sulfur 73.59 %.The flowsheet can produce gold and silver on the spot, meanwhile lead and sulfur can be recovered comprehensively.%对吉林省某矿含铅金银矿石进行了浮选工艺试验研究.根据矿石性质,针对矿石中金、银、铅品位较低的特点,试验采用原矿混合浮选-精矿氰化-浸渣浮选铅工艺流程,获得回收率:金83.80%,银51.19%,铅77.91%,硫73.59%.采用该工艺流程可实现就地产金银,同时综合回收铅硫.

  9. Trace element geochemistry of zircons from mineralizing and non-mineralizing igneous rocks related to gold ores at Yanacocha, Peru

    Koleszar, A. M.; Dilles, J. H.; Kent, A. J.; Wooden, J. L.


    Zircons record important details about the evolution of magmatic systems, are relatively insensitive to alteration, and have been used to investigate the geochemistry, temperature, and oxidation state of volcanic and plutonic system. We examine zircons that span 6-7 m.y. of calc-alkaline volcanic activity in the Yanacocha district of northern Peru, where dacitic intrusions are associated with high-sulfidation gold deposits. The 14.5-8.4 Ma Yanacocha Volcanics include cogenetic lavas and pyroclastic rocks and are underlain by the andesites and dacites of the Calipuy Group, the oldest Cenozoic rocks in the region. We present data for magmatic zircons from the Cerro Fraile dacitic pyroclastics (15.5-15.1 Ma) of the Calipuy Group, and multiple eruptive units within the younger Yanacocha Volcanics: the Atazaico Andesite (14.5-13.3 Ma), the Quilish Dacite (~14-12 Ma), the Azufre Andesite (12.1-11.6 Ma), the San Jose Ignimbrite (11.5-11.2 Ma), and the Coriwachay Dacite (11.1-8.4 Ma). Epithermal high sulfidation (alunite-bearing) gold deposits are associated with the dacite intrusions of the Coriwachay and Quilish Dacites. Zircons from the non-mineralizing rocks typically have lower Hf concentrations and record Ti-in-zircon temperatures that are ~100°C hotter than zircons from the mineralizing intrusions. Temperatures recorded by zircons from the mineralizing intrusions are remarkably similar to those of the underlying Cerro Fraile dacite pyroclastics, but the zircons discussed here generally record SHRIMP-RG 206Pb/238U ages within error of previously published Ar-Ar eruption ages (eliminating antecrystic or xenocrystic origins). These observations suggest that zircons in the mineralizing intrusions form after greater extents of crystallization (and thus record elevated Hf concentrations and lower temperatures) than do zircons in the non-mineralized deposits. Unlike zircons from mineralized units associated with the porphyry Cu(Mo) deposits in Yerington, Nevada, which




    佐家庄金矿床是通过对1:10万的水系沉积物测量预测的金矿远景区开展的1:2.5万土壤地球化学测量发现的。通过分析研究金及其指示元素的异常特征和分带特征等地球化学特征来预测金矿体的空间位置和找矿潜力。佐家庄金矿床属中型的三台山金矿床。%Based on prediction of gold mineralized potential obtained by stream sediment survey at 1 : 100, 000, geochemical soil survey at 1 : 25, 000 commenced in this area discovered the Zuojiazhuang gold deposit. Analysis and researches of anomaly and zoning features of gold mineralization and its indicative elements have made a prediction of the spatial positions and ore-prospecting potential of gold orebodies. Geological investigation and exploration over ten years has developed and renamed Zuojiazhuang gold deposit into the mediumsized Santaizi gold deposit.

  11. Preliminary exploration of ore-controlling conditions of Huichungoubei Gold Deposit in Luoning County,Henan Province%河南省洛宁县回春沟北金矿床控矿条件初探



    The paper summarizes geological achievements in the prospecting phase of Huichungoubei Gold Depos-it,introduces and analyzes the metallogenic geological background and geological characteristics of the deposit(body), and the ore-controlling factors in the district are explored.It is pointed out that the mineral source,the magmatic activi-ty and favorable tectonics are decisive ore-controlling factors.It is necessary to further study the space and time rela-tion between the tectonics in mineralization stage and Yanshanian granite,and to find out the ore-conducting,ore-de-positing structures and the transportation direction and channels of ore-bearing fluids.Also,investment in deep explora-tion should be enlarged to find high and medium temperature hydrothermal deposits near the contact zone of granite and surrounding rocks.%总结了回春沟北金矿床地质找矿的阶段地质成果,对所处的成矿地质背景、矿床(体)地质特征进行了介绍和分析,探讨了本区的控矿条件. 指出矿质来源、岩浆活动、有利的构造3个因素是决定性的控制条件,加强研究成矿期构造和燕山期花岗岩的时空关系,厘清导矿、赋矿构造及含矿热液的运移方向和通道,并应加大深部找矿投入,在花岗岩与围岩接触带附近寻找中高温热液矿床.

  12. Research on Mineral Processing-metallurgy Combination Technology for an Oxidized Gold Ore in Gansu%甘肃某氧化型金矿石选冶技术研究

    毛益林; 陈晓青; 杨进忠; 王秀芬


    甘肃某氧化型金矿石金含量为2.25 g/t,伴生银可综合回收。金主要以独立金矿物形式存在,大部分被载金脉石矿物石英所包裹,少部分以微细粒的形式嵌布在黄铁矿、磁黄铁矿、闪锌矿、黄铜矿和方铅矿等矿物的裂隙中。为高效开发利用该矿石资源,对其进行了选冶联合试验研究。结果表明:在磨矿细度为-0.074 mm占73.00%条件下,经1粗1精2扫浮选、浮选尾矿重选的闭路流程可获得金品位74.2 g/t、回收率91.28%的混合金精矿。混合金精矿经石灰预处理后,经氰化钠浸出,获得了金浸出率为96.52%、金总回收率为88.10%的指标。试验结果对同类型金矿石的选矿回收具有借鉴意义。%The oxidized gold ore in Gansu contains 2. 25 g/t gold and associated silver can be comprehensively recov-ered. Gold mainly exists in form of independent mineral,most gold ore were wrapped in gangue minerals,like quartz,few others was inlayed in the cracks of pyrite,magnetic pyrite,sphalerite,chalcopyrite and galena with the form of fine particles. In order to high efficiently utilize the resource,mineral processing-metallurgy combination experimental research was carried out based on process mineralogy. The results indicate that the mixed concentration with gold grade and recovery of 74. 2 g/t and 91. 28%can be obtained at the grinding fineness of 73. 00% passing 0. 074 mm,via one roughing-one cleaning-two scavenging floatation operation,and gravity separation for floatation tailings. Gold leaching rate of 96. 52% and total recovery of 88. 10% was ob-tained by lime pretreatment with mixed concentrate and then leaching by sodium cyanide. The experimental results can provide technology basis for beneficiation of the ore in same type.

  13. 内蒙古某低品位铜铅锌矿石中金银回收工艺研究%Technologic Study of Mineral Processing on Recovering Some Gold and Silver Ore from Low Grade Copper, Lead and Zinc Ore in Inner Mongolia



    在对内蒙古某低品位铜铅锌矿石工艺矿物学研究的基础上,结合矿石中主要有价组分——金银的计价结算体系,确立了将金银富集到铜铅精矿中的流程思路,进行了铜铅混合浮选、后选锌、再铜铅分离流程的工艺技术条件研究,采用试验确定的磨矿、1粗2扫1精铜铅混浮、磨矿、2次混合精选、1粗1扫1精铜铅分离、1粗2扫4精浮锌、中矿顺序返回闭路流程,可以获得金回收率达85.92%、银回收率达50.99%的铜精矿和金回收率达5.50%、银回收率达17.49%的铅精矿,金总回收率高达91.42%、银总回收率高达68.48%.%Based on the research of process mineralogy to some low grade copper, lead and zincores containing gold and silver ore in Inner Mongolia,combining the value system of gold and silver,the main value component in the ore,the flow project of concentrating gold and silver to copper and lead concentrates is confirmed. According to the technical study of bulk flotation of copper-lead,copper-lead separation,flotation of zinc later,the closed circuit,ore grinding,mixed flotation of copper,lead of one roughing, two scavenging, one concentrate,another grinding, two bulk concentrate,separate of copper, lead of one roughing,one scavenging,one concentrate,zinc flotation of one roughing,two scavenging,four concentrate,middling return in sequencers determined. The copper concentrate of gold recovery 85.92% .silver recovery 50. 99% ,and the lead concentrate of gold recovery 5. 50% .silver recovery 17.49% are gained. The total recovery of gold is 91.42% ,the total recovery of silver is 68.48% in copper concentrate and lead concentrate.

  14. Geology, Ore-microscopy and Fluid inclusion study on Auriferous Quartz Veins at the Gidami Gold Mine, Eastern Desert of Egypt

    Abd El Monsef, Mohamed; Salem, Ibrahim; Slobodnik, Marek


    The gold deposits are represented by auriferous quartz veins and aplitic dykes that are cutting through granitic rocks. The main lode of gold is confined to two principal veins occupying fracture zones and fissures. The main auriferous vein is striking mainly NNW-SSE with dipping 85° NE, it extends up to 450 m with an average thickness 120 cm. The second vein is striking NW-SE and dipping 60° E, it extends for 150 m with an average thickness 35 cm. The gold bearing veins are made up of fine grained quartz that is always massive, milky-white with reddish or greenish tint. They commonly include vugs, some of them are occasionally filled with iron oxides, carbonate and clay minerals. Sometimes the quartz veins enclose remnants of altered wall rock materials as an indication for the metamorphic or syntectonic nature of the veins. Brecciation, comb layering, swelling and nodules manganese dendrites are usually detected. The microscopic examination for thin and polished sections of auriferous quartz veins revealed that quartz and calcite are the predominant minerals commonly associated with accessory minerals (fluorite, apatite, zircon, muscovite and sericite). Ore mineral assemblage is found as disseminated sulfide minerals (pyrite, sphalerite, chalcopyrite, molybdenite, pyrrhotite covellite, galena and pentlandite). Ilmenite and goethite are the main iron oxide mineral phases. Gold most commonly occurs as small inclusions within pyrite or goethite. Gold also occurs as tiny grains scattered within quartz vein (in close proximity to the sulfides) or as disseminated grains in the altered wall rocks. Hydrothermal alteration includes silicification, kaolinitization, sericitisation, carbonatisation confined to a delicate set of veins. Petrography and microthermometry of fluid inclusions revealed that the majority of inclusions are of primary/pseudosecondary nature that occur in clusters and along growth zones or along intra-granular planar trails (pseudosecondary

  15. 云南某黄金选矿厂工艺技术改造及生产实践%Process optimization and its production practice in one gold ore-dressing plant,Yunnan Province

    刘志斌; 汪勇; 高起方


    云南某金矿是中国西南地区最大的黄金多金属共伴生矿山,其选矿厂原采用“全泥氰化浸出—弱磁选—强磁选”工艺对该矿多金属氧化矿石中的金、银、铁进行回收。为了提高金、银浸出率和铁回收率,对该选矿厂进行了控氰抑铜富氧浸出—差异化优先浸吸—脱泥梯级磁选的技术改造。生产实践表明:改进工艺实际生产指标与原工艺流程比较,金浸出率提高了12.16百分点,银浸出率提高了15.14百分点,总铁回收率提高了18.44百分点,经济效益显著。%The gold mine in Yunnan is the largest gold poly-metallic mine in southwest China .A whole ore cyani-dation leaching-low intensity magnetic separation -strong magnetic separation process is used to recover gold ,silver and iron from the poly-metallic oxide ores in the ore-dressing plant .To increase the leaching rate of gold and silver as well as the recovery rate of iron ,a renovation process of cyanide control copper suppression atmospheric leaching -dif-ferential preferential leaching and adsorption -desliming stepped magnetic separation is applied in the plant .Produc-tion practice show that the renovated process compared to the previous one increases gold leaching rate by 12.16 percent points,silver leaching rate by 15.14 percent points,iron recovery rate by 18.14 percent points,achie-ving satisfactory profits .

  16. 青海某铁帽型金银矿石氰化浸出试验研究%The Experimental Study on Cyanidation Leaching of a Gossan Type Gold-Silver Ores in Qinghai Province



    为开发利用铁帽型金银矿产资源,对青海某铁帽型金银矿石进行了氰化法浸出试验研究,考察了磨矿细度、浸出时间、矿浆浓度、NaCN 用量、石灰用量和醋酸铅用量等因素对金银浸出率的影响,进而确定了最佳浸出条件。试验结果表明:在磨矿细度-0.074 mm 占98.23%,矿浆浓度33.33%,石灰用量10 kg/t,氰化钠用量2.5 kg/t,醋酸铅用量100 g/t 以及浸出时间24 h 条件下,该矿石中金、银浸出率分别达到93%和83%以上。该研究成果为青海某铁帽型金银矿的开发利用提供了技术支撑,并对同类型矿石资源的高效开发具有重要的借鉴意义。%In order to develop and utilize mineral resources in gossan type gold and silver ores,cyanide leaching was applied to study the gossan type gold and silver ores in Qinghai Province.We investigated the effect of grinding fineness,leaching time,pulp density,dosage of sodium cyanide,lime and lead acetate to leaching rate for gold and silver,finally the optimum leaching condition was determined.The results showed that grinding fineness of -0.074 mm accounted for 98.23%,pulp density around 33.33%,lime dosage of 10 kg/t,the dosage of sodium cyanide of 2.5 kg/t,lead acetate of 100 g/t,and under the leaching time of 24 h,the leaching rate of gold and silver was above 93% and 83%,respectively.The results provided technical support for the development and utilization of gossan type gold silver ores in Qinghai Province,and it is of great significance for the efficient development of the same kind of resource.

  17. 安徽某金铅锌硫化矿选矿新工艺试验研究%Experimental Study on a New Mineral Processing Technology for a Gold -Lead-Zinc Sulfide Ore in Anhui Province

    冯章标; 俞献林; 陈江安


    For a gold-lead-zinc complex polymetallic sulfide ore in Anhui has a problem such as the low ore dressing indexes,the dosage of reagent system is complex and big.The mineral composition and ore characteristic of raw-ore is analyzed and a large number of exploratory experiments is explored.The last put forward the principle of process to deal with the ore by magnetic separation removal of pyrrhotite,gold-lead bulk flotation,gold-lead separation flotation,activation of tailings flotation zinc.By closed circuit texts can obtain the good indicators,and the gold concent rate with the Au grade of 43.67×10-6 and recovery rate of 46.11%;lead concentrate with the Au grade of 162.00×10-6 and recovery rate of 35.39%, Pb grade of 38.53% and recovery rate of 72.24%,the accumulation of the gold recovery rate is 81.50%;zinc concent rate with the Zn grade of 42.76% and recovery rate of 67.46%.This new method has a better index than the traditional process,as it can not only improve dressing indexes,but reduce a lot reagents dosage.%针对安徽某金铅锌复杂多金属硫化矿选矿指标较低、药剂制度复杂且用量大等问题,分析了原矿的矿物组成及矿石性质,并开展了大量探索性试验,最后提出采用磁选脱除磁黄铁矿—金铅混合浮选—金铅分离浮选—尾矿活化选锌的原则流程处理该矿石。结果显示:闭路试验可获得金含量为43.68×10-6,回收率为46.12%的金精矿;铅精矿中金含量为162.00×10-6,回收率为35.39%,铅含量为38.53%,回收率为72.24%,金的累积回收率达81.51%;锌精矿中锌含量为42.79%,回收率为67.51%。与原有选矿工艺相比,新工艺不仅提高了选矿指标还大幅减少了药剂用量。

  18. A Research of Ore-Forming Conditions of Nipu Gold Deposit in Guizhou Province, China%贵州泥堡金矿床成矿地质条件研究

    孙军; 聂爱国; 黄思涵; 付斌; 陈世委


    The Nipu gold deposit is one of the important components of Carlin-type gold mining area, which is located in Southwest of Cuizhou Province. However, Nipu has its remarkable characteristics in host rocks, gold bearing formation and lithofacies palaeogeography. By researching the forming conditions of Nipu gold deposit, it is found that the mater and heat sources of Nibao gold deposit come from the Emei mantle plume's activities whichis the prerequisites of forming and activating the Ore-bearing hydrothermal. Also the location and formation of Nibao gold deposit are ultimately determined by a large scale of orogenic movements in Yanshanian period.%泥堡金矿是黔西南卡林型金矿矿集区的重要组成部分,但在赋矿岩石、含金建造和岩相古地理位置方面,泥堡金矿具有显著的特殊性.本文通过对贵州泥堡金矿床成矿地质条件的研究,分析认为峨眉山地幔热柱的活动为泥堡金矿的形成提供了物质来源和热能来源,为含矿热液的形成和活动创造了前提条件,燕山期大规模的构造造山运动最终决定了泥堡金矿的定位和形成.

  19. 辽西北票二道沟金矿的成矿特点和黄铁矿热电性特征%Ore-forming Characteristics and Pyroelectricity of Pyrite of the Erdaogou Gold Deposit, Beipiao, Western Liaoning

    王鹏; 董国臣; 李志国; 聂飞; 陈友长; 孙凡; 王霞; 董美玲


    通过对辽西北票二道沟金矿Ⅲ号脉的不同中段的矿石组构、金的分布特点和主要载金矿物立方体、五角十二面体及它形黄铁矿的热电性研究,讨论了成矿特征,计算了成矿温度和矿体剥蚀率并对深部找矿远景进行了预测.研究表明:二道沟金矿金的分布特点存在不均匀性;黄铁矿热电性以P型为主且变化范围宽,只有少量的N型,表明矿体的剥蚀率较低.二道沟金矿可能存在多期次的热液活动,且每一期次相互叠加改造;成矿热液来自南东方向,成矿热液早期温度较高,金属元素大量沉淀温度为150 ~300℃,属中低温,且不同中段的成矿温度有一定的变化规律.不同晶形的黄铁矿热电性研究表明,不同晶形载金能力不同,黄铁矿热电性P型频率不同,形成的温度不同,但计算的矿体剥蚀率相差不大.%According to the ore texture, gold occurrence, shape and pyroelectricity of pyrites of vein Ⅲ in the Erdaogou gold deposit in Western Liaoning, the authors discussed the ore-forming temperatures, denudation rates and evaluated the ore deep prospects. The studies prove that the gold occurrence in the ores was unhomo-geneous. The pyrite was mainly P-type and varied widely, with a few N-type, in terms of pyroelectricity, which indicated that a few part of the orebody was removed by uplift and erosion. Possibly, there were several hydro-thermal activities superposed each other in the Erdaogou gold deposit. The metallogenic hydrothermal solution came from southeast direction. Though the initial hydrothermal temperature was high, most metal minerals precipitated when the temperature ranged from 150 to 300 ℃ , indicating that the Erdaogou gold deposit belonged low-medium hydrothermal type. The pyroelectricity measurements of pyrite indicated that denudation rate was similar, even though the pyrites were different in frequency of P-type, forming temperature and gold content.

  20. Western Australia Kalgoorlie Gold Field Ore-forming Geological Characteristics%西澳大利亚卡尔古丽金矿区成矿地质特征

    李华; 杨恺


    卡尔古丽金矿区(Kalgoorlie Gold Filed)是西澳大利亚最大的金矿产区,在大地构造上属于西澳伊尔岗(Yil-garn)克拉通东部卡尔古丽绿岩带内。矿区主要出露太古代地层,包括镁铁质-超镁铁质熔岩序列、长英质火山碎屑岩序列,以及一系列侵入的基性-超基性岩脉。区域内的主构造为北北西向,包括一对结构不对称的水平褶皱--卡尔古丽背斜和向斜,以及与向斜西翼平行的Golden Mile断层,主构造被后期走滑断层影响形成的破碎剪切带,是赋存金矿的主要构造。根据控矿构造、矿质来源和沉积时间,可以将金矿脉分为三种类型,分别是Fimiston型、Oroya型和Charlotte型。研究认为,在该地区找矿主要应从围岩、构造、地球物理、地球化学几个方面着手。通过对本区成矿地质特征的分析和研究,新发现了Eureka小型金矿,希望能对中国企业在该地区的勘探投资有所帮助。%The Kalgoorlie gold field is the largest gold production area in Western Australia, tectonically the area is within the Yilgarn craton east part Kalgoorlie greenstone belt. Mainly Archean strata outcropped in the mine area, including mafic-ultramafic lava se-quence, felsic pyroclastic rock sequence and a series of intrusive basic-ultrabasic veins. Main structure in the area is NNW structurally asymmetrical horizontal fold pair-Kalgoorlie anticline and syncline, and syncline west limb parallel Golden Mile fault;the main struc-ture fractured shear zone formed by subsequent strike-slip fault impacting is the main structure hosted the gold ore. Based on ore-con-trolling structure, material source and deposit time, can divide gold vein into three styles:Fimiston, Oroy and Charlotte respectively. The study reckoned that the prospecting in the area should start with wall rock, structure, geophysical, geochemical aspects. Through the analysis and study of the ore-forming geological

  1. 广东那程银金多金属矿地质特征及找矿方向研究%Geological Characteristics and Prospecting Direction of Nacheng Silver Gold Polymetallic Ore in Guangdong Province

    刘昌明; 范震宇


    那程银金多金属矿是武警黄金第九支队在广东云开地区发现的一个中等规模的银金多金属矿,矿区位于华南褶皱系西段,云开隆起核部和吴川-四会深大断裂中部。矿区断裂发育,岩浆活动强烈,成矿地质条件良好,脉体较多且有成群产出特征,矿脉主要受次一级张扭性断裂控制,其空间排列具雁式左行规律。通过近几年大量的研究工作,共圈定银金多金属矿体10个,且深部呈现银金多金属元素富集程度增高的趋势,显示了较好的找矿前景。通过研究矿体赋存特征、矿石质量、矿石结构构造、矿石化学成分和成矿阶段矿物生成顺序,探讨矿床成因并总结找矿标志,为在该矿区深部和边部进一步开展找矿勘探、扩大其远景规模提供了较为详实的地质资料。%Nacheng silver-gold polymetallic ore mine found in Yunkai area,Guangdong,is a medium scale mine.It is located in the core of Yunkai uplift and the centre of Wuchuan-Sihui fault,in the western section of South China fold system.It has good ore-forming geological conditions around the mining area,along with faults developing and strong magma action.A lot of veins with characteristic of ore output in groups,which is mainly controlled by the lower-level tensorshear faulting,as a result,its space arrangement showing the pattern of intensively left addressed.In recent years,through the large research work,outlining 10 mine areas for the gold-silver polymetallic ore,all of which present an increase trend of silver gold polymetallic ore enrichment,showing a good prospect for finding mineral resources.Through the study of ore deposition,quality,texture and structure, chemical composition and metallogenic stages of mineral formation sequence,we discussed the deposit genesis, summarized the prospecting marks,and provided detailed geological data for further prospecting and mining scale expanding in deep and edge.

  2. 西藏雄村斑岩型铜金矿集区Ⅰ号矿体的硫、铅同位素特征及其对成矿物质来源的指示%Sulfur and Lead Isotope Characteristics of No.Ⅰ Ore Body in the Xiongcun Porphyry Copper-Gold Ore Concentration Area of Tibet:Implications for the Source of Metals in the Ore Deposit

    郎兴海; 唐菊兴; 李志军; 黄勇; 丁枫; 王成辉; 张丽; 周云


    The Xiongcun porphyry copper-gold ore concentration area, one of the large-size metallogenic areas discovered along the Gangdise porphyry copper belt, occurs in an island arc environment associated with northward intra-oceanic subduction of Neo-Tethys oceanic crust. The ore-forming age of the Xiongcun porphyry copper-gold ore concentration area is middle Jurassic. It is located in the middle of the southern margin of the Gangdise orogenic belt, and its south margin is Shigatse forearc basin. The latest exploration data indicate that there are several potential mineralization-alteration areas and three large-size copper-gold ore bodies (No. I, II and Ⅲ) in the Xiongcun porphyry copper-gold ore concentration area. In this paper, Xiongcun No. I ore body was chosen as the research object. According to sulfur and lead isotope composition of ore-baring porphyry, tuff and main sulfides of the ore, the authors have reached the following two conclusions: 1) Sulfur isotopic compositions vary in a narrow range of δ34S values from -3.5‰ to +2.7‰ (-1.07‰ on average) and are close to zero, indicating a mantle sulfur signature. 2) They have uniform Pb isotope compositions with low content of radiogenic Pb. The 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb ratios vary in the ranges of 18.104-18.432, 15.473-15.533 and 37.918-38.3072, respectively. They are located in the transition zone of mantle Pb and orogen Pb but are closer to the former, reflecting a mixing between the mantle material and minor crust material. Through a comparative study of sulfur and lead isotopes of porphyry copper deposits of the island arc environment (e.g., Xiongcun No. I ore body) and those of the collisional orogenic environment in the Gangdise porphyry copper belt, the authors found that they have similar metal sources, but porphyry copper deposits of the island arc environment have experienced weak contamination of crust materials, whereas porphyry copper deposits of the coilisional orogenic

  3. Kellad orelis


    18. VI Tallinna toomkirikus organist Ines Maidre (kaastegev Kristjan Mäeots) kontsert "Kellad orelis". Kontserdiga esitleb I. Maidre ka oma samanimelist CD-d (kujundaja Margus Haavamägi), mis on osaliselt sisse mängitud Tallinna toomkiriku Ladegasti-Saueri orelil. Tänavu tähistatakse toomkiriku Maarja kella ja Lunastaja kella 315. aastapäeva.

  4. Research on the nitration pre-leaching technique of one sulfur-containing oxide gold ore%某含硫氧化金矿硝酸预浸技术研究

    郭月琴; 孙志勇; 吴天骄


    针对某难浸氧化金矿石的矿石性质,采用硝酸预浸技术进行提金试验研究. 其结果表明:在最佳试验条件下,可获得金浸出率87 . 86 %、银浸出率76 . 56 %的较好指标. 相对于其他处理工艺,硝酸预浸技术可以显著提高金、银的浸出率,并降低氰化物的消耗量,减轻生产成本压力,达到了资源最大化利用和综合回收的目的.%In light of the hard-to-leach property of one oxide gold ore,experimental research is conducted using nitration pre-leaching technique. The results show that under optimal conditions,gold leaching rate can reach 87. 86%and silver leaching rate 76. 56 %. Compared to other treatment techniques,nitration pre-leaching technique signifi-cantly increases gold and silver leaching rate and reduces the consumption of cyanide,cutting production cost and a-chieving the goal of full utilization of resources and comprehensive recovery.

  5. Gold recovery from refractory ores. The role of pressure oxidation. Recuperacion de oro de minerales refractarios. El papel de la oxidacion a presion

    Alguacil, F.J.; Cobo, A.; Caravaca, C. (Consejo Superior de Investigaciones Cientificas. Centro Nacional de Investigaciones Metalurgicas. Madrid (Spain))


    Pressure oxidation is a hydrometallurgical technique that renders auriferous refractory materials, specially sulphides, amenable to cyanidation process. The effectiveness of the operation as a pretreatment to the recovery of refractory gold, is reflected by the succesful startup over the last ten years of seven commercial plants. Some factors affecting the selection of pressure oxidation as pretreatment for gold recovery are discussed. (Author)

  6. Ore Prospecting Prospect Analysis of the Gold Polymetallic Deposit at Fourteen Section Region in Heilongjiang Province%黑龙江十四工段地区金多金属矿找矿前景分析



    The gold polymetallic deposit at fourteen section region located at middle part of the Zhangguangcailing-Taipingling edge uplift belt.It was found that the volcano-magmatic activity was frequent in the area,together with structure development and good ore-forming geological conditions.Through 1/50 000 stream sediment survey work in the study area,approximately 205 ingle element anomalies of stream sediments were identified,additionally,26 combination anomalies of stream sediments were also defined and these include the Hs-18 combination anomalies. In order to search for gold dominated polymetallic ore at the fourteen section area,verification work was carried out at the Hs-18 combination anomalies.The methods applied in this study including 1/20 000 soil measurement,1/20 000 geological detection,1/2 000 high-precision magnetic measurement,IP ladder measurement and methods of trenching.Finally,we defined 89 single element anomalies for soil,8 combination anomalies,one low grade gold ore body,one gold mineralization body, which suggested that the area has good ore prospects.%十四工段地区金多金属矿处于张广才岭—太平岭边缘隆起带中部。区内火山—岩浆活动频繁,构造发育,具备良好的成矿地质条件。在该区通过开展1/5万水系沉积物测量工作,圈出水系沉积物单元素异常205处,水系沉积物组合异常26处,其中 Hs-18号组合异常位于研究区内。为在十四工段地区寻找以金为主的多金属矿产,对 Hs-18号组合异常进行了查证,采用1/2万土壤测量、1/2万地质简测、1/2万高精度磁法测量、激电中梯测量及槽探等方法,在区内圈定出土壤单元素异常89处,组合异常8处,发现低品位金矿体1条、金矿化体1条,表明该区具有较好的找矿前景。

  7. 贵州省册亨县尾若金矿点地质特征及找矿方向%Geological Characteristics and Ore-searching Directions of Weiruo Gold Occurrence in Ceting County of Guizhou Province

    丁俊; 张洪信; 罗建均; 肖波


    贵州册亨县尾若金矿产于北东向F2断裂破碎带内,含金地层为三叠系许满组,矿化围岩为泥灰岩、泥质粉砂岩,围岩蚀变有硅化、黄铁矿化、碳酸盐化、黏土化、毒砂化、脱钙;矿体呈扁豆状、透镜状、脉状产出,矿化体(带)长200 m,矿化带(体)水平厚度1.00 m~5.20 m,平均品位Au为0.50×10-6~6.37×10-6。%The Weiruo gold ore in Ceting County of Guizhou Province is produced within NE trend F2 faulted fracture zone, the gold-bearing beds belong to Xuman Group of Triassic System, the mineralized surrounding rocks are mud-limestone and argillaceous siltstone, and the alteration of surrounding rocks includes the siliconization, pyritization, carbonatization, argillization, arsenopyritization and decalcification;the ore body presents the lenticular, lenticular and vein output, the length of mineralized body(belt) is 200 m, the the level thickness of mineralized belt(body) is 1.00 m~5.20 m, and the average grade of Au is 0.50×10-6~6.37×10-6.

  8. 内蒙古某高砷金矿石碱浸预处理-氰化浸出试验研究%Alkali Leaching Pretreatment-Cyanide Leaching Experiments on a High Arsenic Gold Ore in Inner Mongolia

    何毅; 高柏年; 姚凯


    Gold grade of Inner Mongolia Laodonggou Gold Mine is 8.27 g/t,associated silver can be recovered,arsenic content is as high as 3.1 8%.Gold is finely disseminated and mainly exists in other minerals in inclusions form and closely symbiotic,and easily sliming.Heap leaching method was used on the on-site process while the gold leaching rate is only 50%,resource was seriously wasted.To increase the gold leaching rate,on the basis of the analysis of ore properties,alkali leaching pretreatment-all slime cyanidation leaching process at room temperature was put forward.The optimum leaching conditions de-termined are as follows:the grinding fineness of 93.5% -0.074 mm,pulp solid-liquid ratio is 1 ∶2,ad-justing the pH =1 2,alkali leaching NaOH dosage of 3 000 g/t,pretreatment for 2.5 h,leaching agent NaCN dosage of 2 000 g/t,leaching for 24 h,eventually gold and silver leaching rate were 85.49% and 80.1 2%,respectively.By heap leaching process,the gold leaching rate increased by 35 percentage points,and silver was comprehensive recovered,and the economic benefit is remarkable,can be used as the gold ore new extraction process.%内蒙古老硐沟金矿金品位波动较大,综合金品位8.27 g/t,可伴随回收银,砷含量高达3.18%。矿石中金嵌布粒度细微,主要以包裹体形态存在于其它矿物中,共生关系密切,且泥化严重。现场采用堆浸法生产,金浸出率仅50%左右,资源浪费严重。为提高金浸出率,在分析矿石性质的基础上,提出采用常温碱浸预处理—全泥氰化浸出工艺,条件试验确定的最佳浸出条件为:磨矿细度-0.074 mm 93.5%,矿浆固液比为1∶2,调节 pH =12,碱浸 NaOH 用量3000 g/t,预处理2.5 h,浸出剂 NaCN 用量为2000 g/t,浸出24 h,最终金、银浸出率分别为85.49%、80.12%。相比堆浸工艺,金浸出率提高了35个百分点以上,并综合回收了银,经济效益显著,可作为该

  9. Characteristics of ore-controlling structure in Maevatanana gold deposit,Madagascar%马达加斯加 Maevatanana 金矿床构造控矿特征

    杨喜安; 刘善宝; 王光良; 黄凡; 李鹏; 王成辉; 陈毓川


    Madagascar sits in eastern Africa ,ranking the fourth largest island in the world .To this day ,there is no organised or industrialized gold exploitation in Maevatanana region besides manual mining work .This is a large amount considering that all is presently from artisanal mining of mainly alluvial deposits .The region's estimated gold produc-tion is 3-4 tonnes/year.The Au deposit in the Maevatanana region is a classical quartz vein type gold deposit in the greenstone belt by the results of chemical test of drill cores ,the quartz veins was controlled by faults .The chemical tes-ting of the drill core demonstrates that the gold deposits in the Madagascar mainly comprise gold-bearing quartz veins , subordinating the gold-bearing felsic veins .The late gold-bearing quartz veins crosscut the gold-bearing felsic veins , suggesting that there is two epochs of mineralization in the study area .The gold-bearing felsic veins are hosted by the NNW-trending shear zone ,and the gold-bearing quartz veins is related to the intersection of the NNW-trending shear zone and the NNE-striking faults .The NNE-striking faults reworked and crosscut the gold-bearing quartz veins .%马达加斯加位于非洲东部,是世界第四大岛。到目前为止,马达加斯加Maevatanana 地区还没有进行工业化开采金矿床,主要靠手工开采,估计马达加斯加每年的金产量3~4t左右。根据钻孔岩芯化验结果可知,本地区的矿化类型主要为含金石英脉,其次为含金长英质脉。后期的含金石英脉切穿了早期的含金长英质脉,说明该地区具有2期成矿作用。含金长英质脉容矿构造为NNW向剪切带,含金石英脉产在NNW向剪切带和NNE向断层交汇处。 NNE向断层后期活动,破坏了含金石英脉。

  10. Evolution of ore deposits on terrestrial planets

    Burns, R. G.


    Ore deposits on terrestrial planets materialized after core formation, mantle evolution, crustal development, interactions of surface rocks with the hydrosphere and atmosphere, and, where life exists on a planet, the involvement of biological activity. Core formation removed most of the siderophilic and chalcophilic elements, leaving mantles depleted in many of the strategic and noble metals relative to their chondritic abundances. Basaltic magma derived from partial melting of the mantle transported to the surface several metals contained in immiscible silicate and sulfide melts. Magmatic ore deposits were formed during cooling, fractional crystallization and density stratification from the basaltic melts. Such ore deposits found in earth's Archean rocks were probably generated during early histories of all terrestrial planets and may be the only types of igneous ores on Mars. Where plate tectonic activity was prevalent on a terrestrial planet, temporal evolution of ore deposits took place. Repetitive episodes of subduction modified the chemical compositions of the crust and upper mantles, leading to porphyry copper and molybdenum ores in calc-alkaline igneous rocks and granite-hosted tin and tungsten deposits. Such plate tectonic-induced mineralization in relatively young igneous rocks on earth may also have produced hydrothermal ore deposits on Venus in addition to the massive sulfide and cumulate chromite ores associated with Venusian mafic igneous rock. Sedimentary ore deposits resulting from mechanical and chemical weathering in reducing atmospheres in Archean earth included placer deposits (e.g., uraninite, gold, pyrite ores). Chromite, ilmenite, and other dense unreactive minerals could also be present on channel floors and in valley networks on Mars, while banded iron formations might underlie the Martian northern plains regions. As oxygen evolved in earth's atmosphere, so too did oxide ores. By analogy, gossans above sulfide ores probably occur on Mars

  11. Evolution of ore deposits on terrestrial planets

    Burns, R. G.


    Ore deposits on terrestrial planets materialized after core formation, mantle evolution, crustal development, interactions of surface rocks with the hydrosphere and atmosphere, and, where life exists on a planet, the involvement of biological activity. Core formation removed most of the siderophilic and chalcophilic elements, leaving mantles depleted in many of the strategic and noble metals relative to their chondritic abundances. Basaltic magma derived from partial melting of the mantle transported to the surface several metals contained in immiscible silicate and sulfide melts. Magmatic ore deposits were formed during cooling, fractional crystallization and density stratification from the basaltic melts. Such ore deposits found in earth's Archean rocks were probably generated during early histories of all terrestrial planets and may be the only types of igneous ores on Mars. Where plate tectonic activity was prevalent on a terrestrial planet, temporal evolution of ore deposits took place. Repetitive episodes of subduction modified the chemical compositions of the crust and upper mantles, leading to porphyry copper and molybdenum ores in calc-alkaline igneous rocks and granite-hosted tin and tungsten deposits. Such plate tectonic-induced mineralization in relatively young igneous rocks on earth may also have produced hydrothermal ore deposits on Venus in addition to the massive sulfide and cumulate chromite ores associated with Venusian mafic igneous rock. Sedimentary ore deposits resulting from mechanical and chemical weathering in reducing atmospheres in Archean earth included placer deposits (e.g., uraninite, gold, pyrite ores). Chromite, ilmenite, and other dense unreactive minerals could also be present on channel floors and in valley networks on Mars, while banded iron formations might underlie the Martian northern plains regions. As oxygen evolved in earth's atmosphere, so too did oxide ores. By analogy, gossans above sulfide ores probably occur on Mars

  12. Biomining: metal recovery from ores with microorganisms.

    Schippers, Axel; Hedrich, Sabrina; Vasters, Jürgen; Drobe, Malte; Sand, Wolfgang; Willscher, Sabine


    Biomining is an increasingly applied biotechnological procedure for processing of ores in the mining industry (biohydrometallurgy). Nowadays the production of copper from low-grade ores is the most important industrial application and a significant part of world copper production already originates from heap or dump/stockpile bioleaching. Conceptual differences exist between the industrial processes of bioleaching and biooxidation. Bioleaching is a conversion of an insoluble valuable metal into a soluble form by means of microorganisms. In biooxidation, on the other hand, gold is predominantly unlocked from refractory ores in large-scale stirred-tank biooxidation arrangements for further processing steps. In addition to copper and gold production, biomining is also used to produce cobalt, nickel, zinc, and uranium. Up to now, biomining has merely been used as a procedure in the processing of sulfide ores and uranium ore, but laboratory and pilot procedures already exist for the processing of silicate and oxide ores (e.g., laterites), for leaching of processing residues or mine waste dumps (mine tailings), as well as for the extraction of metals from industrial residues and waste (recycling). This chapter estimates the world production of copper, gold, and other metals by means of biomining and chemical leaching (bio-/hydrometallurgy) compared with metal production by pyrometallurgical procedures, and describes new developments in biomining. In addition, an overview is given about metal sulfide oxidizing microorganisms, fundamentals of biomining including bioleaching mechanisms and interface processes, as well as anaerobic bioleaching and bioleaching with heterotrophic microorganisms.

  13. Origin of Gold-Bearing Fluid and Its Initiative Localization Mechanism in Xiadian Gold Deposit, Shandong Province

    邓军; 王庆飞; 孙忠实


    The composition of quartz inclusions and trace elements in ore indicate that gold bearing fluid in the Xiadian gold deposit, Shandong Province, stemmed from both mantle and magma, belonging to a composite origin. Based on theoretical analysis and high temperature and high pressure experimental studies, gold-bearing fluid initiative localization mechanism and the forming environment of ore-host rocks are discussed in the present paper. The composite fluid extracted gold from rocks because of its expanding and injecting forces and flew through ore-conducive structures, leading to the breakup of rocks. The generation of ore-host faults and the precipitation of gold-bearing fluid occurred almost simultaneously. This study provides further information about the relationships between gold ore veins and basic-ultrabasic vein rocks and intermediate vein rocks, the spatial distribution of gold ore veins and the rules governing the migration of ore fluids.

  14. Nonlinear Effects of Laser Surface Modification of Ore Minerals

    N.A. Leonenko


    Full Text Available The effect of continuous laser radiation on complex ore minerals objects containing gold, not extracted by monerd methods was investigated. It was established the formation of different structural surfaces of gold, revealed general patterns of sintering and concentration of sub-micron gold.

  15. Study on organic extraction-flame atomic absorption spectrometry determination of gold in ore%有机萃取—火焰原子吸收法测定岩矿中金的探讨

    张明祖; 覃路燕; 郭炳北


    在现有的有机萃取—原子吸收法测定岩矿中金的基础上,以乙酸丁酯、甲基异丁基甲酮(MIBK)为萃取剂进行比较,考察了两者对金的萃取性能.实验研究了KBr和Fe3+对有机萃取—原子吸收法测定金的影响,并对其他共存离子的干扰情况进行了探讨,优化了实验条件.%On the basis of the current organic extraction-flame atomic absorption spectrometry determination of gold in ores, butyl acetate and methyl isobutyl ketone (MIBK) were compared as extractants, and their extraction performance for gold was studied. The experiments on the effects of KBr and Fe3+ on the organic extraction-atomic ab-sorption spectrometry were carried out. The paper also investigated the interference of other coexist ions and optimized the experimental conditions.

  16. Paleoproterozoic Sediment- hosted Gold Deposits in Eastern Liaoning, Northeast China: Implications for Gold Exploration

    Yang Dejiang


    Gold deposits in eastern Liaoning, northeast China are hosted in the middle and upper parts of a Paleoproterozoic volcanic - sedimentary succession, which consists of interlayered carbonates and fine - grained clastics. This paper discusses the geological features of ore - bearing formations, ore- controlling structures and metallogenetic characteristics. Analysis of ore - controlling factors suggested that the schists from the Gaixian formatyion, syngenetic faults and ductile shear zones are principal ore controls over mineralization and thereafter indicators for gold exploration.

  17. The Ore-controlling Factors and Prospecting Indicator of Qingshuiquan Gold Deposit in Xinjiang Province%新疆清水泉金矿床控矿因素及找矿标志

    赵海滨; 田红彪; 张希兵; 韦定君; 田璐


    清水泉金矿床位于新疆东准噶尔地区重要的金及多金属成矿带--卡拉麦里成矿带西段,产于清水-苏吉泉大断裂与卡拉麦里深断裂之间。区内构造活动强烈,次级断裂及裂隙发育,构成以NW向为主的强蚀变碎裂岩带;岩浆活动频繁,老鸦泉岩体呈岩基状分布于区内北部,构成金属元素迁移活化富集的强大热源;出露地层主要为中石炭统清水组浅变质岩系,并均已接受后期强烈的变形变质作用,发育塑性流动变形石香肠和剪切褶皱等构造形迹。清水泉金矿床类型属破碎蚀变岩夹石英脉型,矿体呈带状和透镜状赋存于与近EW向主构造体系相交的次级构造组中,富集不均匀,矿体形态、分布和矿化富集受地层、构造密切控制,并与岩浆活动热源有关。含金地质体与构造、脉岩分布及矿化蚀变是主要的找矿标志。%Qingshuiquan gold deposit is located in the west of gold and polymetallic ore belt,Kalamaili metallogenic belt in eastern Junggar,and outputted between Qingshui-Sujiquan big break and Kalamaili deep faults. In this region,the violent tectonic activities and the secondary faults and fracture development which constitute a strongly altered cataclasite zone mainly along northwest direction.Magmatic activity is frequent.Laoyaquan rock is distributed in the north and showed rock foundation appearance,which is powerful heat source for the migration of activated metals enrichment in the region.Outcropping strata are mainly middle Carboniferous Qingshui Formation which is a shallow metamorphic rock,has accepted the latter strongly deformed and metamorphosed,and developmental the boudin and shear fold.Qingshuiquan gold deposit is a broken altered rock-quartz vein type deposits.Ore bodies are banded and lenticular which occur in the secondary structure group intersected at nearly EW main structural system.Ore enrichment is uneven,its morphology

  18. 吉林荒沟山金矿床成矿流体特征%Geochemical Characteristics of Ore-Forming Fluid in Huanggoushan Gold Deposit,Jilin Province

    周向斌; 李剑锋; 王可勇; 梁一鸿; 张淼; 韦烈民; 王志高


    荒沟山金矿床为吉南老岭金-多金属成矿带内较具代表性矿床之一,产于元古宇老岭群珍珠门组地层之中,受韧性剪切带构造控制。按地质特征、矿物组合及矿脉之间的穿切关系,将荒沟山金矿床热液成矿作用划分为Ⅰ黄铁矿-毒砂-石英阶段和Ⅱ晚期辉锑矿-乳白色石英两个阶段。系统的流体包裹体岩相学及显微测温研究表明:Ⅰ阶段石英中发育含 CO 2三相、碳质及气液两相3种类型的原生流体包裹体,成矿流体属不混溶的中低温、低盐度 NaCl-H 2 O-CO 2体系热液,在成矿过程中发生过不混溶作用而导致金等有用元素沉淀富集;Ⅱ阶段石英颗粒中主要发育气液两相包裹体,成矿流体属均匀的 NaCl-H 2 O 体系热液。碳、氢、氧同位素研究表明,Ⅰ阶段成矿流体主要来源于岩浆热液,Ⅱ阶段流体除继承早阶段的热液外,还有大气降水的混入;δD 和δ13 CV-PDB 值分析结果证明两个成矿阶段流体均与地层发生过较强的水岩反应。矿床成因属于中温岩浆热液矿床。%Occurred in Zhenzhumen Formation of Laoling Group of Proterozoic Era and controlled by ductile shear belt,the Huanggoushan gold deposit is one of the most representative deposits in Laoling gold-polymetallic metallogenic belt in southern Jilin Province.Based on the geological characteristics,mineral assemblage and the crosscutting relationship between different kinds of veins,the hydrothermal mineralization processes can be divided into two main stages,namely,stageⅠpyrite arseno-pyrite quartz and stageⅡ later stibnite-milky quartz.Systematic study on petrography and microthermometry of fluid inclusions shows that quartz of Stage Ⅰcontains three types of primary fluid inclusions,which are CO 2 bearing three phases,carbonic and aqueous two phases inclusions respectively,and the ore forming fluid is of medium to low temperature and low salinity NaCl-H 2 O-CO 2 kind of

  19. Arsenic bioleaching in medical realgar ore and arsenic- bearing ...

    medical realgar ore that allowed much higher leaching rates ... bioleaching behavior between mixed unadapted ... Acid drainage from copper mine, Zhongtiao Mountain, Shanxi,. China ..... during high temperature bioleaching of gold-bearing.

  20. Structural controls and evolution of gold-, silver-, and REE-bearing copper-cobalt ore deposits, Blackbird district, east-central Idaho: Epigenetic origins

    Lund, K.; Tysdal, R.G.; Evans, K.V.; Kunk, M.J.; Pillers, R.M.


    The Cu-Co ± Au (± Ag ± Ni ± REE) ore deposits of the Blackbird district, east-central Idaho, have previously been classified as Besshi-type VMS, sedex, and IOCG deposits within an intact stratigraphic section. New studies indicate that, across the district, mineralization was introduced into the country rocks as a series of structurally controlled vein and alteration systems. Quartz-rich and biotite-rich veins (and alteration zones) and minor albite and siderite veinlets maintain consistent order and sulfide mineral associations across the district. Both early and late quartz veins contain chalcopyrite and pyrite, whereas intermediate-stage tourmaline-biotite veins host the cobaltite. Barren early and late albite and late carbonate (generally siderite) form veins or are included in the quartz veins. REE minerals, principally monazite, allanite, and xenotime, are associated with both tourmaline-biotite and late quartz veins. The veins are in mineralized intervals along axial planar cleavage, intrafolial foliation, and shears.

  1. Mineralogical, fluid inclusion, and stable isotope constraints on mechanisms of ore deposition at the Samgwang mine (Republic of Korea)—a mesothermal, vein-hosted gold-silver deposit

    Yoo, Bong Chul; Lee, Hyun Koo; White, Noel C.


    The Samgwang mine is located in the Cheongyang gold district (Cheonan Metallogenic Province) of the Republic of Korea. It consists of eight massive, gold-bearing quartz veins that filled NE- and NW-striking fractures along fault zones in Precambrian granitic gneiss of the Gyeonggi massif. Their mineralogy and paragenesis allow two separate vein-forming episodes to be recognized, temporally separated by a major faulting event. The ore minerals occur in quartz and calcite of stage I, associated with fracturing and healing of veins. Hydrothermal wall-rock alteration minerals of stage I include Fe-rich chlorite (Fe/(Fe+Mg) ratios 0.74-0.81), muscovite, illite, K-feldspar, and minor arsenopyrite, pyrite, and carbonates. Sulfide minerals deposited along with electrum during this stage include arsenopyrite, pyrite, pyrrhotite, sphalerite, marcasite, chalcopyrite, galena, argentite, pyrargyrite, and argentian tetrahedrite. Only calcite was deposited during stage II. Fluid inclusions in quartz contain three main types of C-O-H fluids: CO2-rich, CO2-H2O, and aqueous inclusions. Quartz veins related to early sulfides in stage I were deposited from H2O-NaCl-CO2 fluids (1,500-5,000 bar, average 3,200) with T htotal values of 200°C to 383°C and salinities less than about 7 wt.% NaCl equiv. Late sulfide deposition was related to H2O-NaCl fluids (140-1,300 bar, average 700) with T htotal values of 110°C to 385°C and salinities less than about 11 wt.% NaCl equiv. These fluids either evolved through immiscibility of H2O-NaCl-CO2 fluids as a result of a decrease in fluid pressure, or through mixing with deeply circulated meteoric waters as a result of uplift or unloading during mineralization, or both. Measured and calculated sulfur isotope compositions (δ34SH2S = 1.5 to 4.8‰) of hydrothermal fluids from the stage I quartz veins indicate that ore sulfur was derived mainly from a magmatic source. The calculated and measured oxygen and hydrogen isotope compositions (δ18OH2O

  2. Endogenic Au-Ag polymetallic ore deposits and ore-bearing potentiality of strata

    WANG Baode; NIU Shuyin; SUN Aiqun; XIE Yan; LUO Yi; LIU Hailong; WANG Yanhua


    The problem of ore-bearing potentiality of the strata involves metallogenic theory and ore-search orientation. Studies of the spatial distribution of endogenic Au-Ag polymetallic ore deposits in North Hebei indicated that the strata in which ore deposits occurred range in age from Paleozoic, Proterozoic to Mesozoic. In addition the ore deposits are characterized as being strata-bound in nature. The arise and establishment of "extracting" viewpoint may be attributed to the following three reasons: 1) influence by the idea of "ore-source bed"; 2) limitation of analytical techniques in the 1980s' (especially gold element); and 3) a small number of samples (sampling locations were mostly disturbed by mineralization). Studies have shown that ore-forming materials would most probably come from the deep interior of the Earth. Deep-seated ore-bearing materials including Au-Ag polymetals were brought to the shallow levels by way of mantle plume-mantle sub-plume-mantle branch structure multi-stage evolution, finally leading to the formation of ore deposits.

  3. 甘肃拾金坡金矿床成因:来自40Ar/39Ar定年、成矿流体及H-O-S同位素证据%Ore Genesis of the Shijinpo Gold Deposit in Gansu Province, NW China:40Ar/39Ar Dating, Ore-Forming Fluid and H-O-S Isotopes Constrains

    朱江; 吕新彪; 莫亚龙; 曹晓峰; 陈超


    , variably coexisting with minor amounts of galena, sphalerite and chalcopyrite. Laser incremental heating 40Ar/39Ar analysis of hydrothermal sericite yields a plateau age of (364. 6 ± 3) Ma (2σ) , which suggests that the gold mineralization took place in the late Devonian period. The comprehensive fluid inclusion study shows that there are three major types of fluid inclusions in the early stage: liquid-rich, gas-rich aqueous and CO2-bearing fluid inclusions, with intermediate homogenization temperature (280 - 325℃) , and low salinity (7. 86%- 9. 21% NaCl eqv). The fluid boiling is evidenced by the co-existence of three types of fluid inclusions with similar homogenization temperatures. There is only liquid-rich aqueous fluid inclusions in the late stage, with hqmogenization temperatures and salinities varying from 160℃ to 230℃ , 9. 47% to 11. 10%Nacl equivalent. Fluid pressures declined from ca. 113 MPa to ca. 11 MPa through the early stage to the late stage, and the ore-forming fluids are assumed to undergo boiling in a transitional setting (from compression to extension). Oxygen and hydrogen isotopic contents in the ore-forming fluid range from 1. 39%o to 3. 39%o and - 71%o to -99%o, respectively, suggesting that the ore-forming fluid was mainly derived from the metamorphic water, and mixed by the meteoric water in the late stage. The measured δ34 S values in sulfide minerals range from 4. 44%o to 11. 33%o. Both the Precambrian metamorphic rock and granitic wall-rock might be the sulfur sources. Based on the paper and the regional geologic data, we conclude that the Shijinpo gold deposit belongs to the orogenic-type gold deposit.

  4. 新城金矿盲竖井矿石溜井塌方段快速修复施工技术与实践%Construction Technology and Practice in Quick Restoration of the Collapsed Section of the Ore Chute of the Blind Shaft in Xincheng Gold Mine

    付常鹏; 黄永庆; 戚克辉; 周新勍


    新城金矿盲竖井矿石溜井在生产过程中-830 m 水平至-930 m 水平井壁多次塌方,大块毛石堵塞下部振动放矿机,造成盲竖井矿石提升系统瘫痪。矿石溜井修复期间,结合现场施工条件,采取简单实用的施工设备,严格按设计要求施工,圆满地完成了该工程,并介绍了该段矿石溜井快速修复的成功经验。%For the ore chute in Xincheng Gold Mine,the ore lifting system broke down in the blind shaft as a result of several collapses of the horizontal well walls ranging from -830m to -930m in production process and subsequent blocking of large bubbles in the lower vibrating ore - drawing machine. In order to repair the failing ore chute,simple and practical construction equipment are used and construction as set out in the design by taking into account field construction conditions are carried out. At the end,the project achieves complete success at a high rate of speed. The article mainly provides successful ways of quick repairing the section of the ore chute.

  5. 浮选柱单独处理金矿矿泥的试验研究%Experimental study on processing of gold ore slime only using flotation columns

    王攀志; 卞英娟; 姜浩刚


    The metal recovery is affected because there is more slime in the gold ore of Jiaojia Gold Mine. In order to study the influence of independent processing slime on recovery, the slime was treated separately. The pilot test for slime processed by flotation column is carried out. The influences of processing capacity, dosage of collector and frother are surveyed, and the flotation effects are contrasted. The results show that processing slime only using flotation column has obvious advantages than processing slime only using flotator, the recov ery rate improves by 10.02%. The study offers technical parameters for the second-stage extension.%焦家金矿处理的矿石含泥量多,影响金属回收.为探明单独处理矿泥对回收率的影响,对选矿工艺中的矿泥进行了浮选柱半工业试验,考察了处理量、捕收剂用量和起泡剂用量等因素的影响,并且与浮选机的浮选效果进行了比较.结果表明,单独采用浮选柱处理矿泥比单独用浮选机处理矿泥具有明显的优势,回收率提高了10.02%,经济效益显著,为二期扩建提供了技术参数.

  6. A probe into structural ore-control mechanism in the Yangshan gold ore belt in Gansu,evidence from calcite red girdle study%甘肃阳山金矿带构造控矿机理探讨--来自方解石红色环带研究的证据

    孟献真; 孙丹青; 王绍祥


    阳山金矿带内主要容矿岩石为泥盆系灰岩、千枚岩,灰岩裂隙中常发育晶形完好的方解石(冰洲石)晶簇,方解石晶体中发育明显的红色环带,利用扫描电镜及X-射线能谱成份分析结果显示红色环带方解石含微量的锰和铁,推断致色离子为Mn2+,和Fe3+;而Fe3+的存在指示环带生长于金矿的主成矿期;颜色交替环带状结构发育,指示主成矿阶段流体系统进入到温度周期性升降、压力逐渐释放的开放环境。%Major ore-bearing rocks are Devonian limestone and phyllite in the Yangshan gold belt,and limestone frac-tures usually host calcite (Iceland spar) druses with well grown crystal forms. Red girdles are well developed in calcite crystals. SEM and X-ray energy spectrum analytical results indicated that red-girdle calcite contains trace Mn and Fe, and the color is presumably caused by Mn2+ and Fe3+,and Fe3+ suggests that girdle grew in the prime gold mineraliza-tion period. The development of color alternation girdle texture shows that fluid system in the prime mineralization time goes into an open environment with periodic up and down of temperature and gradual release of pressure.

  7. Ore-forming fluid and stable isotope studies of Dazhuangzi gold depositin Jiaodong Peninsula%胶东大庄子金矿成矿流体及稳定同位素研究

    刘玄; 范宏瑞; 胡芳芳; 郑小礼; 蓝廷广; 杨奎锋


    胶东大庄子金矿床位于胶北地体西南缘,中生代胶莱盆地北缘,西侧靠近郯庐(沂沭)断裂带.矿体产出在古元古界荆山群变质岩中,发育碎裂(糜棱)蚀变岩型和石英脉型2种矿石.流体包裹体显微测温表明,主成矿期温度为240~280℃,成矿流体盐度w(NaCleq)为7% ~8%,属于H2O-CO2-NaCl体系.包裹体显微测温及岩相学观察发现,成矿期流体发生了相分离作用,这可能是导致矿化的主要原因之一.氢、氧同位素测试显示石英δ18O石英值变化于10.9‰~ 11.8‰之间,石英包裹体δ18OH2o变化于4.3‰~5.2‰,δDH2O变化于-65.8‰~-74.5‰,表明大庄子金矿成矿期流体以岩浆水为主,成矿后期混入了一定量的大气降水,岩浆水可能来自于与基性脉岩同源的基性岩浆的去气作用.硫同位素分析获得硫化物δ 34S值为7.9‰~11.3‰,与围岩荆山群变质岩硫同位素组成非常接近,而与胶东群变质岩和中生代花岗岩的硫同位素组成差别较大,因此认为大庄子金矿床成矿流体中的硫主要来自于荆山群变质岩.%The Dazhuangzi gold deposit lies in Pingdu City, Shandong Province. Tectonically, it is located in the southwestern corner of Jiaobei terrain and on the northern margin of the Mesozoic Jiaolai basin; to the west, it is adjacent to the Yishu fault zone. The ore bodies, which are hosted in metamorphic rocks of Paleoproterozoic Jingshan Group, can be divided into two types, namely the "altered cataclasite or mylonite type" and the "quartz vein type". Microthermometric investigation reveals that gold precipitation occurs at 240 ~ 280℃ from CQ2-rich, low salinity [ω(NaCleq)7%~8%] hydrothermal fluids in which there are no other volatiles except H2O and CQ2. More importantly, phase separation is observed and is firmly believed to be responsible for the main stage mineralization. Results of hydrogen and oxygen isotope studies suggest that ore-forming fluids were a mixture

  8. Application of Wire-line Coring Hydro-hammer in Xiaoqinling Gold Ore Deposit%绳索取心液动潜孔锤钻进技术在小秦岭金矿区的应用

    杨宽才; 田敏; 曾石友; 蔡记华


    The paper introduced the application of SYZX75 wire-line coring hydro-hammer in Xiaoqinling gold ore deposit of Lingbao City of Henan Province with the application effects.The field trial results show that the unit monthly drilling effi-ciency, average hour efficiency, round trip length and core recovery rate in cracked formation are improved obviously with lower drilling cost and better protection effect of borehole deviation.%  介绍了SYZX75型绳索取心液动潜孔锤在河南省灵宝市小秦岭金矿区的试验应用及其效果。试验结果表明,钻探台月效率、平均时效、回次长度和破碎地层岩心采取率均有明显提高,钻探成本下降,防止孔斜效果好,值得进一步推广。

  9. 新疆东昆仑古尔嘎哈拉曲哈研究区金、钨矿找矿方向和靶区圈定%Gold, tungsten ore prospecting direction and target delineation of Gu’ergahalaquha study area in Xinjiang East Kunlun

    李永宽; 陈明鉴; 邹家林; 董云侠


    In this paper, the writers described typical deposits features and prospecting criteria metallogenic belt of gold, tungsten regional metallogenic belt, which in the Gu’erga Halaquha study area of Xinjiang East Kunlun. We summarized the geology and mineral features of the study area, ore-forming geological conditions, geochemical anomaly combination features, typical mineralized spots features and the known ore occurrence metallogenic factors and genetic types. Pointed out the prospecting direction, to find gold, tungsten ore body in the altered tectonic zone and fracture zone, where containing the metal sulifde mineralization, strong siliciifcation, chloritization, epidotization, sericitization. Optimizing delineated the gold and tungsten ore prospecting target area.%叙述了新疆东昆仑古尔嘎哈拉曲哈研究区金、钨矿区域成矿带典型矿床特征和找矿标志成矿带,总结了研究区地质矿产特征、成矿地质条件、化探异常组合特征和典型矿化点特征,研究了已知矿点成矿因素、成因类型。指出了找矿方向,在含有金属硫化物等矿化,同时具有较强的硅化、绿泥石化、绿帘石化、绢云母化等蚀变构造带、断裂带内找金、钨等矿体。优选圈定了金、钨找矿靶区。

  10. Research of Geochemical Associations of Nephelin Ores

    Vulf, M.; Simonov, K.; Sazonov, A.

    The instant paper concerns research of distribution petrogenic chemical members in urtit ore body of Kia-Shaltyrsk deposit. Rocks of the deposit are ore for producing alum earth. Actuality of the subject based on outlooks of detection noble metal ore-bearing (Au, Pt, Pd, Rh, Ru) in alkaline rocks of Siberia, including rocks of Kia-Shaltyrsk deposit (Kuznetsk Alatau). The main purpose of analysis of distribution of members is directed to detection of a non-uniformity of distribution of substance and segments enriched with alum earth and noble members. The basic solved problems are following: o Creation regression models of ore body; o Definition of cumulative distribution functions of members in a contour of ore body; o The analysis of the obtained outcomes in geologic terms. For construction regression models the full-scale data was used, which was presented by the results of the spectral and silicate analyses of gold and petrogenic members containing 130 assays arranged in ore body. A non-linear multiparameter model of the ore body based on components of nephelin ore using neural net approach was constructed. For each member the corresponding distribution function is produced. The model is constructed on the following members: Au, Al2O3, SiO2, Fe2O3, CaO, MgO, SO3, R2O ((Na2O+K2O) -1) and losses of burning. The error of model forecasting membersS concentrations was from 0.02 up to 20%. Large errors basically connected with assays located near contact of ore body and ad- jacent strata or with very high concentrations of members; also they can be connected with different genesis of rocks or superposition of other processes. The analysis of concentrations of members and normalised absolute errors of the fore- cast has shown, that all members can be sectioned into two groups: first: Al2O3, SiO2, R2O, Fe2O3 and second: Au, losses of burning, CaO, MgO, SO3. The distribution of 1 gold is tightly connected with calcium and losses of burning and spatially linked with zones

  11. The extractive metallurgy of gold

    Kongolo, K.; Mwema, M. D.


    Mössbauer spectroscopy has been successfully used in investigation of the gold compounds present in ores and the gold species which occur during the process metallurgy of this metal. This paper is a survey of the basic recovery methods and techniques used in extractive metallurgy of gold. Process fundamentals on mineral processing, ore leaching, zinc dust cementation, adsorption on activated carbon, electrowinning and refining are examined. The recovery of gold as a by-product of the copper industry is also described. Alternative processing methods are indicated in order to shed light on new interesting research topics where Mössbauer spectroscopy could be applied.

  12. 青海某低品位微细浸染型易泥化难处理金矿选矿试验研究%Study on flotation test for low-grade fine-disseminated and easily argillous refractory gold ore from Qinghai

    邢晴晴; 明平田; 熊召华; 陈自强


    One low-grade fine-disseminated and easily argillous refractory gold ore from Qinghai is wrapped in ar-senopyrite and pyrite taking the form of microscopic and ultra microscopic scattering,and contains a number of easily argillous minerals which occupies 37. 07 %. According to the ore property,the paper adopts a process of ore and mud separation and intensified flotation, which generates a good test index; closed circuit obtains gold concentrates with gold grade of 37. 56 g/t and gold recovery of 85. 57 %. At the same time,the process,taking advantage of recycled water utilization,can effectively save water,reduce reagent consumption and lower production cost.%青海某低品位微细浸染型易泥化难处理金矿石金大多呈显微和超显微分散状态包裹于毒砂和黄铁矿中,且易泥化矿物含量高,为37.07%。针对其矿石性质,采用矿泥分散+强化浮选工艺流程,获得了较好的试验指标:闭路浮选金精矿金品位37.56 g/t,金回收率85.57%。同时,通过回水循环利用,可有效节约水资源,减少药剂用量,降低生产成本。

  13. Gold process mineralogy: Objectives, techniques, and applications

    Zhou, Joe Y.; Cabri, Louis J.


    The extractive metallurgy of gold is largely driven by mineralogical factors such as gold particle size; association with other minerals; coatings; presence of cyanicides, oxygen consumers, and preg-robbers; presence of refractory gold minerals; and locking of submicroscopic gold in sulfide and sulfarsenide mineral structures. Gold process mineralogy addresses all issues related to gold ore processing by the detailed study of an ore or a mill product. The methodology is widely used as a predictive tool in feasibility studies and during the process development stage, and as a trouble-shooting tool for mineral processing and hydrometallurgical operations.

  14. 湖北蛇屋山红土型金矿床PSDs特征及其意义%PSDs characteristics and its significance of Shewushan lateritic gold ore deposit, Hubei province



    土壤颗粒粒度分布(PSDs)是复杂物理化学作用的结果,研究表明,分形理论是刻画这一复杂过程的有利工具.通过对蛇屋山金矿床赋矿红土的PSDs研究发现,赋矿红土颗粒平均粒度在3.42~28.53μm之间,同时从风化壳浅部到深部有增加的趋势.分形统计学研究表明,赋矿红土PSDs,在1.71~9.46μm范围内具有分形特征(R2>0.94),分维值(D)变化范围为2.86~2.22.红土剖面样品的矿物组成、伊利石结晶度Kubler指数以及样品颗粒粒级的综合分析认为,随着Kubler指数不断增加,流体-土壤作用增强,黄铁矿的氧化、长石的黏土化等导致土壤颗拉由粉粒向私粒的转化.D值与黏粒/粉粒含量的良好相关性指示了流体-土壤相互作用而导致红土颗粒的细粒化这一过程,具有一定的普适性.因此,颗粒粒度分形特征可以作为评价红土型风化成土过程的重要指标.%Previous studies showed that particle-size distributions (PSDs) of soil were resulted from complex physical-chemical processes and could be efficiently described by fractal theory.According to the research on PSDs of the ore-hosting laterite of Shewushan gold deposit, we found that the average particle sizes of the laterite are varied from 3.42 to 28.53 μm and the values increase as the altitude decreases.Fractal statistics studies showed that the ore-hosting laterite has the fractal characteristics ranging between 1.71 and 9.46 μm (R2 >0.94) and the fractal dimensions(D) change from 2.22 to 2.86.Moreover, the mineral composition, Kübler index of illite crystallinity and panicle size fraction data suggested that as the increasing of the Kübler index, fluid-soil reaction becomes strong and the oxidation of pyrite and the argillization of feldspar may result in the transformation from the silt to clay.The fine correlations between the D values and caly/silt indicated that the processes of fluid-soil interaction which caused the particle size

  15. Controls on the distribution of arsenic in lake sediments impacted by 65 years of gold ore processing in subarctic Canada: the role of organic matter

    Galloway, Jennifer; Palmer, Michael; Swindles, Graeme T.; Sanei, Hamed; Jamieson, Heather E.; Parsons, Michael; Macumber, Andrew L.; Patterson, Tim; Falck, Hendrik


    Gold mines in the Yellowknife region of the Northwest Territories, Canada, operated from 1938 to 2003 and released approximately 20,000 tonnes of arsenic trioxide to the environment through stack emissions. This release resulted in highly elevated arsenic concentrations in lake surface waters and sediments relative to Canadian drinking water standards and guidelines for the protection of aquatic life. High northern latitudes are experiencing substantial impacts, including changes in bio-physico-chemical processes, due to climate change. Determining the affect of warming climate on contamination is complicated by the fact that little is known of climate change controls on As mobility and bioavailability. Further, while the role of dissolved organic matter in As cycling is relatively well characterized in soils and wetland sediments, few studies have investigated the role of solid organic matter in lacustrine systems. We use a meta-analytical approach to better understand controls on sedimentary arsenic distribution in lakes within a 50 km2 area of historic mineral processing activities. Arsenic concentrations in near surface sediments of the 100 lakes studied range from 5 mg/kg to over 10,000 mg/kg (median 81 mg/kg). Distance from the historical Giant Mine roaster stack and the amount of labile organic matter (S1 carbon as determined by Rock Eval pyrolysis) in lake sediments are the variables most strongly correlated with sedimentary As concentrations (Spearman's rank correlation As:distance from historic roaster rs=-0.57, phydrocarbons derived from readily degradable geolipids and pigments predominantly originating from authochthonous organic matter, represents a small portion of the overall total organic carbon in the sedimentary material analyzed (median 2.33 wt.%). However, this fraction of organic matter has large potential to influence element concentrations in lake sediments through coating of pre-existing solid-phase As-mineral complexes, direct As

  16. Experimental Research on Micro-disseminated Gold Ore Pretreated by Alkaline and Non-cyanide Leaching%微细浸染型金矿碱预处理-非氰化浸出研究

    唐立靖; 唐云; 王燕南; 杨典奇


    The thesis focuses on research of the micro-disseminated gold ore.Explored the extraction effects,under the condition of wet milling,with non-cyanide leaching agent,pre-treating with lime and sodium carbonate,mixed system is more efficiency than single pretreatment system,which may influenced by the generation of sodium hydroxide.The reaction of sodium hydroxide with quartz and pyrite make the package gold exposed,which is beneficial to the leaching of gold.When inflating in the pretreatment and leaching process,leaching effect is better. This may be oxygen participate in the reaction or reduce the thickness of the diffusion layer and solid film thickness.The results showed that under the conditions of lime dosage was 50 kg/t,sodium carbonate dosage was 2 kg/t,pretreatment time was 4 h,a non-cyanide leaching agent was 10 kg/t,leaching time was 14 h,liquid-to-solid ratio was 3∶1,inflatable amounts was about 0.5 m3/h,the gold leaching rate of 86.09% was achieved.%以微细浸染型金矿为研究对象,比较研究了 CaO、Na2CO3及 CaO-Na2CO3混合碱预处理体系的处理效果。结果表明,采用 CaO-Na2CO3混合碱预处理,金浸出效果要优于单一预处理,这与混合体系生成NaOH 有关,NaOH 与石英及黄铁矿作用,使包裹的金暴露出来,有利于金的浸出。在预处理和浸出过程充气时,浸出效果要优于不充气,这是因为空气中氧气参与了反应,充气降低了扩散层的厚度或使固膜减薄,大幅提高了金的浸出率。试验结果表明,在 CaO 用量为50 kg/t、Na2CO3用量为2 kg/t、预处理时间为4 h、浸出剂用量为10 kg/t、液固比为3∶1、浸出时间为14 h、充气量为0.5 m3/h 的条件下,金浸出率可达86.09%。

  17. 西藏雄村铜金矿Ⅰ号矿体赋矿凝灰岩成因探讨:来自岩石地球化学、Sr-Nd-Pb同位素地球化学特征的证据%The Genesis of Mineralized Tuff of No.Ⅰ Ore Body in the Xiongcun Porphyry Copper-Gold Metallogenic Ore District, Tibet: Evidence from Geochemistry and Sr-Nd-Pb Isotopes

    丁枫; 郎兴海; 胡正华; 杨欢欢; 王子正; 张丽


    雄村斑岩型铜金矿集区位于冈底斯造山带中段南缘,目前发现的Ⅰ、Ⅱ、Ⅲ号主矿体均产于含矿斑岩体及其接触带附近的凝灰岩中,本文主要对雄村Ⅰ号矿体赋矿凝灰岩开展岩石地球化学特征研究.赋矿凝灰岩显示出与岛弧火山岩相似的地球化学特征,如相对富集LREE、LILE而亏损HREE、HFS以及低的I(sr)值(变化范围为0.704163~0.705369,均值0.704907)和正的εNd(t)值(变化范围为3.7805~7.6286,均值5.904121)等,其形成与印度-亚洲大陆碰撞造山之前的新特提斯洋俯冲作用有关,产于新特提斯洋向北的洋内俯冲作用而形成的岛弧环境.赋矿凝灰岩起源于岛弧底部的新生玄武质岩层的部分熔融,源岩主要由角闪石、斜长石和少量石榴子石组成.赋矿凝灰岩、含矿斑岩体和成矿作用同属一个火山-岩浆-热液系统,赋矿凝灰岩为成矿提供了必要的围岩外部因素,是矿区重要的控矿因素,也是一个重要的找矿地质条件.在雄村矿区及其外围,侵位于凝灰岩中的斑岩体应该是今后找矿评价的重点区域.%The Xiongcun porphyry copper-gold metallogenic ore concentration area is located in the north of the middle Gangdise orogenic belt. No. Ⅰ, Ⅱ and Ⅲ main ore bodies of Xiongcun area are hosted in ore-bearing porphyries and tuff along the contact zone. This paper mainly studied geochemistry of mineralized tuff in Xiongcun No. I ore body. The mineralized tuff is similar to volcanic rocks in island arc in such geochemical characteristics as relative enrichment of LREE and LILE, depletion of HREE and HFS, low I(Sr) values (raning from 0.704163 to 0.705369, 0.704907 on average), and positive εNd(t) values (ranging from 3.7805~7.6286, 5.904121 on average). Mineralized tuff was formed in an island arc environment and was related to northwards subduction of the Neo-Tethys Ocean which occurred before India - Asian continental collision, and its source

  18. 马鞍桥微细浸染型(沉积岩容矿)金矿床(体)快速定位预测研究%On the rapid-positioning and prediction for microdissemination type (sedimentary rock host) gold deposit (ore bodies),Ma′anqiao

    李福东; 邹湘华; 高纪璞; 陆瑶; 张月红


    Ma′anqiao gold deposit is one of mast important gold deposits, occurring in sedimentary strata, in the middle-west part of Qinling——“Central Orogen”, China and reaches into a large scale in reserves; and its potential of resources adds year after year. The gold deposit has typical significance in the metallogenic mechanism and evolutionary pattern and can be compared with well known gold deposits of the samp type at home and abroad.   Major achievements of the study are as follows.   1.It is clearly pointed out that the metallogenic geotectonic environment of Ma'anqiao gold deposit is located at the plate obduction zone in the fore-arc basin on south margin of North China plate. The major interface of Shang-Dan fault belt on south margin of North China plate is removed southward 10 km away, lying on the Banfangzi-Xiaowangjian line, sharply distincting from formerly northern margin of Yangtze plate.   2.The age of ore-bearing rock series "Wangjiahe Fm.", being certainly confirmed, could be attributed to the early Paleozoic Era rather than the Devonian Period, being concluded before.   3.The Danfeng Gr. Microlithon(Pt3-PZ1dn) and Dacaotan Gr. Microlithon(D3) have been breaked up from the formerly-designated Davonian Wangjiahe Fm., therefore, the existence of the partial carboniferous system has been denied; the new regional stratigraphic sequence has been reordered and the new appearance(PZ1wj) of ore-bearing rock series “Wangjiahe Fm.”has been set up on the basis of two suits of conglomerate. In addition, it is further expounded that Wangjiahe Fm. Should belong to a series of turbidite of the deep- water clinoform facies and is a component part of the important geological body on south margin of North China plate, which is formed by several microlithons overlapped.   4.Described in detail that the metallogenesis of Au in gold deposit of this type underwent, from the early Paleozoic to early Yenshan time, a very long evolutionary

  19. Gold—depleted Zone and Its Metallogenic Significance,Yinshan Ore Field,Jiangxi Proveince,China

    华仁民; 陈克荣; 等


    Based on gold analyses of 213 samples of the Shuangqiaoshan Group in an area of 225km2 with the Yinshan polymetallic ore district as the center, a depleted zone of gold is recognized around the ore district, suggesting that the Shuangqiaoshan Group may be a source bed for gold .Discus-sions were given concerning the alteration-mineralization features of the Yinshan deposit, the ore-controlling mechanism of the NE-trending fault zone and promising targets for further ore pros-pecting.

  20. 含砷金矿细菌氧化提金废渣综合回收砷%Comprehensive Recovery of Arsenic from Bio-oxidation Gold Ore Slag

    孙光勇; 王卫亭; 杨军; 杨譞; 张永奎


    With bio-oxidation gold ore slag as raw material, arsenic was recycled from the slag. In arsenic leaching test, four factors had been studied including the usage of sodium hydroxide, leaching temperature, ratio of liquid to solid(L/S), and leaching time. In arsenic precipitate test, three factors including the initial solution pH, mole ratio between Ca and As and the reaction time had been studied. The optimum conditions for arsenic leaching include the optimal amount of NaOH of 240 g/L, 60 ℃, L/S = 4/l, 2 h. Under the optimum conditions, the leaching rate of arsenic was 85%. The optimum conditions for arsenic precipitating include the initial solution pH of 12. 0 and the mole ratio between Ca and As of 2 :1, 30 min, under which more than 97% of arsenic would be precipitated.%以细菌氧化提金废渣为原料,对其中所含的砷进行回收.分别考察了碱用量、浸出温度、液固比和浸出时间对砷浸出率的影响及溶液初始pH、钙砷摩尔比和沉淀时间对砷沉淀率的影响.通过单因素条件试验确定了浸砷的较优条件为:氢氧化钠浓度240 g/L,反应温度60℃,液固比4∶1,搅拌浸出2h.在副优条件下砷浸出率达到85%.从浸出液中沉砷的较优条件为:溶液初始pH=12.0,钙砷摩尔比2∶ 1,沉淀时间30 min.在优化条件下砷沉淀率达到97%以上.

  1. Health Risk Assessment of the Arsenic in Soil and Groundwater around A Gold Ore%某金矿周边土壤和地下水中砷的健康风险评价

    鲁敏; 李荟敏; 贺小敏; 李爱民; 范俊楠


    以湖北某含砷金矿污染场地为例,依据《污染场地风险评估技术导则》(HJ 25.3—2014),对其周边土壤和地下水中砷元素进行健康风险评价,结果表明:该金矿周边土壤和地下水中砷分别通过经口摄入土壤、皮肤接触土壤和吸入土壤颗粒物、饮用地下水4种暴露途径的致癌风险均超过可接受风险水平(10-6),对周边居民造成潜在危害。计算得到经口摄入、皮肤接触和吸入途径基于致癌效应的土壤风险控制值分别为1.6 mg /kg、9.3 mg /kg 和12.1 mg /kg,应予以重视,并建议对矿山进行综合治理和目标值修复。%The health risks of arsenic in soil and groundwater near an arsenic-bearing gold ore in Hubei province was investigated in this work,which was carried out according to the state environmental protection de-partment of contaminated sites risk assessment technology guideline(HJ 25.3—201 4).The results indicates that the carcinogenic risk of the four paths including oral intake of soil and underground water,skin contact and inha-lation of soil particles exceed the acceptable risk level(1 0 -6 ),which could cause potential damage to the people. The calculated risk control value for the oral intake of soil,skin contact and inhalation of soil particles are 1 .6 mg /kg、9.3 mg /kg and 1 2.1 mg /kg,respectively.The results indicated that attention should be paid to the mine comprehensive treatment and target remediation.

  2. Dissolution of the possibility of compounds auriferous sulfide ores in chemical solvents, alternative cyanide

    Tonkova N.V.,Tomchakova D.A.


    Full Text Available Possibility of the use of tiomochevin’s solutions as alternative the cyanides of gold solvents is considereded. It is established, that most effectively to use the offered technological process for extraction of gold from his associations with sulfides. Effectivity of a two-stage processing of gold ores, consisting of the biooxidation and dissolution of tiomocheviny connections stages is shown.

  3. Ores and Climate Change - Primary Shareholders

    Stein, Holly J.; Hannah, Judith L.


    Many in the economic geology community concern themselves with details of ore formation at the deposit scale, whether tallying fluid inclusion data to get at changes in ore-forming fluids or defining structures that aid and abet mineralization. These compilations are generally aimed at interpretation of events at the site of ore formation, with the goal being assignment of the deposit to a sanctioned ore deposit model. While providing useful data, this approach is incomplete and does not, by itself, serve present-day requirements for true interdisciplinary science. The ore-forming environment is one of chaos and disequilibrium at nearly all scales (Stein, 2014). Chaos and complexity are documented by variably altered rocks, veins or disseminated mineralization with multi-generational fluid histories, erratic and unusual textures in host rocks, and the bitumen or other hydrocarbon products entwined within many ore deposits. This should give pause to our drive for more data as a means to find "the answer". The answer lies in the kind of data collected and more importantly, in the way we interpret those data. Rather than constructing an ever-increasing catalog of descriptive mutations on sanctioned ore deposit models (e.g., IOGC or Iron-Oxide Copper Gold deposits), the way forward is to link source and transport of metals, sulfur, and organic material with regional and ultimately whole Earth chemical evolution. Important experimental work provides chemical constraints in controlled and behaved environments. To these data, we add imagination and interpretation, always tying back to field observations. In this paper, several key points are made by way of ore deposit examples: (1) many IOCG deposits are outcomes of profound changes in the chemistry of the Earth's surface, in the interplay of the atmosphere, hydrosphere, biosphere, and lithosphere; (2) the redox history of Fe in deep earth may be ultimately expressed in the ore-forming sequence; and (3) the formation of

  4. Stable isotope characteristics and origin of ore-forming fluids in copper-gold-polymetallic deposits within strike-slip pull-apart basin of Weishan-Yongping continental collision orogenic belt, Yunnan Province, China

    WANG Yong; HOU Zengqian; MO Xuanxue; DONG Fangliu; BI Xianmei; ZENG Pusheng


    More than 140 middle-small sized deposits or minerals are present in the Weishan-Yongping ore concentra-tion area which is located in the southern part of a typical Lanping strike-slip and pull-apart basin. It has plenty of mineral resources derived from the collision between the Indian and Asian plates. The ore-forming fluid system in the Weishan-Yongping ore concentration area can be divided into two subsystems, namely, the Zijinshan subsystem and Gonglang arc subsystem. The ore-forming fluids of Cu, Co deposits in the Gonglang arc fluid subsystem have δD values between -83.8‰ and -69%0, δ18O values between 4.17‰ and 10.45‰, and δ13C values between -13.6‰ and 3.7‰,suggesting that the ore-forming fluids of Cu, Co deposits were derived mainly from magmatic water and partly from formation water. The ore-forming fluids of Au, Pb, Zn, Fe deposits in the Zijinshan subsystem have δD values between-117.4‰ and-76‰, δ18O values between 5.32‰ and 9.56‰,and δ13C values between -10.07‰ and -1.5‰. The ore-forming fluids of Sb deposits have 6D values between -95%0 and -78‰, δ18O values between 4.5‰ and 32.3‰, and δ13 Cvalues between -26.4‰ and -1.9‰. Hence, the ore-forming fluids of the Zijinshan subsystem must have been derived mainly from formation water and partly from magmatic water.Affected by the collision between the Indian and Asian plates,ore-forming fluids in Weishan-Yongping basin migrated con-siderably from southwest to northeast. At first, the Gonglang arc subsystem with high temperature and high salinity was formed. With the development of the ore-forming fluids, the Zijinshan subsystem with lower temperature and lower salinity was subsequently formed.

  5. Silicophosphate Sorbents, Based on Ore-Processing Plants' Waste in Kazakhstan

    Kubekova, Sholpan N.; Kapralova, Viktoria I.; Telkov, Shamil A.


    The problem of ore-processing plants' waste and man-made mineral formations (MMF) disposal is very important for the Republic of Kazakhstan. The research of various ore types (gold, polymetallic, iron-bearing) MMF from a number of Kazakhstan's deposits using a complex physical and chemical methods showed, that the waste's main components are…

  6. Evolution of ore forming fluid of Daping gold deposit in Ailaoshan tectonic zone, Southeast Tibet%青藏高原东南缘哀牢山大坪金矿成矿流体演化

    朱路华; 戚学祥; 彭松柏; 李志群


    Daping gold deposit is a large quartz-vein gold deposit in Ailaoshan tectonic zone, made of north and south fields. Fluid inclusion homogenization temperatures range from 187t to 329t (average is 2811) in north field, and from 168℃ to 338℃ (average is 264℃) in south field, respectively. Corresponding, the δDV-SMOW values range from -70‰to -81‰ and from -71‰to-86‰, and the 518OH2O values rang from 2. 9‰ to 9. 8‰ and from 3. 5‰ to 5. 1‰, respectively. All samples plotted at the field between magmatic water and underground water in the plots of 5D vs. δ18OH2O, and that for north field are near magmatic water area, and for south field are near underground water area. The sulfur isotopic compositions (834 S) for north and south fields are 0. 7‰ ~ 15. 5‰ and 10. 6‰ ~ 15. 8‰, respectively. The vapour compositions in fluid inclusions are H2O, CO2 and N2, with a little of CH4 , C2H2, C2H4, C2H6 and CO. The ion compositions in fluid inclusions are K+ , Na+ , Ca2+ , Cl- and SO42- , with a little of NO3 - , F- , Br- and Mg2-. ESR dating data for quartz in gold-bearing quartz veins from north and south fields are 27. 2 - 29. 1 Ma and 17.3~22. 1Ma, respectively. All above show, that the ore forming fluids are mixing of postmagmatic solution and underground water, from north to south, deep to shallow fields and from earlier to later stage, the contents of the postmagmatic solution and sulfur are decreasing, and that of the underground water is increasing, and the age of minerallization is youngling, gradually.%大坪金矿是青藏高原东南缘哀牢山构造带中的大型石英脉型金矿床,由北矿区和南矿区组成.北矿区和南矿区的成矿流体包裹体均一温度及其氢、氧、硫同位素、气液相成份的测试结果表明其成矿温度为:187~329℃(平均为281℃)和168~338℃(平均为264℃)、氢同位素组成(δDV-SMOW)为:-70‰~-81‰和-71‰~-86‰、氧同位素组成(δ18OH2o)为:2.9‰~9.8

  7. 桐柏山老湾金矿带右行走滑断裂控矿体系的构建及其意义%Establishment and Significance of Dextral Strike-slip Fault Ore-controlling System of the Laowan Gold Belt, Tongbai Mountains

    杨梅珍; 付晶晶; 王世峰; 陆建培


    Focusing on the Shang Shanghe-Peng Jialaozhuang and Laowan-Sheng Laozhuang gold deposits of the Laowan gold metallogenic belt, Tongbai Mountains, the authors investigated the structural nature and assembly patterns of ore-controlling structural zone of the Laowan gold belt based on field investigation, mine channel observation, statistical analysis of fault attitude and assorting, and discussed the coupling between property of fault and mineralization type. The Shang Shanghe-Peng Jialaozhuang gold deposit has well-developed quartz vein type-mineralization, and its ore-controlling faults are characterized by R-type tension-shear fracture of Reidel shear structure, steep dipping northward, trending 290°~310° which strike at an angle of about +15° to the principal shear zone (286°), 10 m of displacement by dextral strike-slip. The Laowan-Sheng Laozhuang gold deposit has altered rock type mineralization without quartz vein. Its ore-controlling faults are characterized by P-type compression-shear fracture of Reidel shear structure, gently dipping southward, trending about 92°, which strike at an angle of about 15° to the principal shear zone (286°), and dextral strike-slip is reflected by the right echelon arrangement of its three large fracture alteration belts. Integrating the information of faults and mineralization of the whole gold belt, we concluded that the ore-controlling fault system of gold belt is a braided dextral strike-slip shear zone by linkages between R and P shears of Reidel shear zone bounded by the Laowan and Songpa faults. Combined with the regional geological evolution of the Tongbai orogenic belt, it is proposed that the brittle shear zone of the Laowan gold belt was as a consequence of further development of early ductile shear zone, reflecting the dynamic mechanism of oblique collision between different tectonic blocks followed by uplift of the Tongbai orogenic belt. The coupling relationship between the dextral strike-slip fault ore

  8. 难处理金矿浸出预处理过程的电位-pH图%E-pH Diagram of Pretreatment of Leaching for Refractory Gold Ore

    金创石; 张廷安; 牟望重; 曾勇


    通过热力学计算绘制了298.15 K下FeS2-H2O系、FeAsS-H2O系的电位-pH图,为难处理金矿浸出预处理过程中黄铁矿与毒砂的氧化分解提供了热力学依据.由FeS2-H2O系的电位-pH图可知,黄铁矿可以被O2等氧化剂氧化分解.在水的稳定区范围内,元素硫的稳定区较小,浸出预处理过程中硫基本上以HSO-4,SO24-形式存在.由FeAsS-H2O系的电位-pH图可知,毒砂比黄铁矿更容易被氧化分解.浸出预处理过程应提高氧化电位使毒砂中的砷和硫氧化至最高价脱去,避免亚砷酸盐和元素硫的生成.以难处理金精矿为原料进行加压氧化验证实验,在反应温度180℃、精矿粒度为-0.075 mm~+0.061 mm、氧分压为0.8MPa、初始酸质量浓度60 g/L、液固质量比4∶1、反应时间120 min、搅拌转速600 r/min条件下,金精矿的平均脱硫率93.85%,平均脱砷率为95.91%,实验结果与热力学计算结果一致.%E-pH diagrams of FeS2-H2O system and FeAsS-H2O system at 298.15 K were drawn to provide the thermodynamic basis for the pretreatment of pyrite and arsenopyrite before leaching.According to E-pH diagram of FeS2-H2O system,pyrite can be decomposed by O2 and other oxidants.The stable region of sulfur element is small and sulfur exists as HSO-4 and SO2-4 basically in the stable region of water.According to E-pH diagram of FeAsS-H2O system,the decomposition of arsenopyrite is easier than pyrite.Oxidation potential was improved to oxidize sulfur and arsenic to be removed and avoid the formation of arsenite and sulfur elements during the pretreatment process.Verification of pressure oxidation was carried out with refractory gold ore.When the temperature,concentrate particle size,oxygen partial pressure,initial acid concentration,liquid-solid mass ratio,reaction time and stirring speed are 180 ℃,-0.075~+0.061 mm,0.8 MPa,60 g/L,4∶1,120 min andd 600 r/min respectively,average desulfurization rate is 93.85% and average arsenic removal rate

  9. Thermoelectric characteristics of pyrite from the main ore zone of the Huachanggou gold deposit, Shaanxi Province and its significance%陕西省铧厂沟金矿床主矿带黄铁矿热电性特征及其地质意义

    刘冲昊; 刘家军; 王建平; 吴杰; 王维钰; 王立新; 于康伟; 陈冬; 李志国


    陕西省铧厂沟金矿是一个主要赋存于海底基性火山喷流细碧岩中的金矿床.文中系统研究了该矿床主矿带黄铁矿的热电性特征.主矿带成矿温度主要集中在130~330℃,属中—低温矿床;黄铁矿导电类型从早期到晚期由N型向P型转变;P型黄铁矿出现频率从浅部到深部呈减小趋势;金品位高值区与P型黄铁矿的高值区及热电系数离散度的低值区相对应;主矿带黄铁矿热电导型及热电性参数特征反映出主矿带开采区位于矿体中部偏下,向深处仍有一定规模的延伸.综合分析认为,0至2勘探线深部以及22~26勘探线深部发现新的富矿段的可能性较大.%The Huachanggou gold deposit in Shaanxi Province mainly occurs in the submarine basic volcanic effusive spilite.On the basis of a study of the thermoelectric characteristics of pyrite,the authors put forward the following conclusions.The main ore zone is a low-medium temperature gold deposit,whose pyrite crystallization temperature is in the range of 130-330 ℃.The electric conduct assemblage type of the pyrite changes in the order of N-type to P-type from the early stage to the late stage.The frequence of P-type pyrites gradually decreases from the shallow part to the deep.The high average gold grade corresponds to the high frequence of P-type pyrites and low value of thermoelectrical coefficient dispersions.The characteristics of thermoelectricity imply that the lower to middle parts of the ore body have been exhumed until now,and there exists an extension of the main ore zone in the deep.Furthermore,the authors suggest that the better exploring prospect would be expectable in the depth of exploration line Nos.0,2 and Nos.22-26.

  10. Alkaline sulfide pretreatment of an antimonial refractory Au-Ag ore for improved cyanidation

    Alp, Ibrahim; Celep, Oktay; Deveci, Haci


    This paper presents the alkaline sulfide pretreatment of an antimonial refractory gold and silver ore. In the ore, gold occurs mainly as gold-silver alloys and as associated with quartz and framboidal pyrite grains, and, to a small extent, as the inclusions within antimonial sulfides. Silver is present extensively as antimonial sulfides such as andorite. Alkaline sulfide pretreatment was shown to allow the decomposition of the antimonial sulfide minerals (up to 98% Sb removal) and to remarkably improve the amenability of gold (e.g., from silver (e.g., from leaching. An increase in reagent concentration (1-4 mol/L Na2S or NaOH) and temperature (20-80°C), and a decrease in particle size seem to produce an enhancing effect on metal extraction. These findings suggest that alkaline sulfide leaching can be suitably used as a chemical pretreatment method prior to the conventional cyanidation for antimonial refractory gold and silver ores.

  11. 滇中小水井金矿床成矿流体地球化学及成因类型探讨%A tentative discussion on ore-forming fluid geochemistry and genetic type of Xiaoshuijing gold deposit in central Yunnan

    周云满; 张长青; 王树琼; 覃修平


    The Xiaoshuijing gold deposit occurs in a ductile-brittle shear zone, with the host rocks being fractured breccia and cataclasite made up of sandstone-mudstone and limestone. Studies of sulfur and carbon isotopic data indicate that the sulfur and carbon in the fluids were mainly derived from the mantle or a deep-seated place. Oxygen-hydrogen stable isotopic data imply that the ore-forming fluids mainly came from the meteoric water through infiltration, circulation and derivation of heat energy from the structural and magmatic activity. Fluid inclusions in minerals are mostly liquid-vapor (aqueous two-phase) inclusions, with minor vapor inclusions. The cations of liquid phase of inclusions in quartz are mainly Na+ and K+ , with Na+/K+ ratio being 3.056 ~ 4.940, while the anions are chiefly Cl- and SO2-4 , characterized by Cl- >SO2-4>F- . The vapor-phase components of inclusions in quartz are composed mainly of H2O and CO2, with minor CH4 and CO. The ore-forming fluids belong to the H2O-CO2-NaCl system. The homogenization temperatures of fluid conclusions at the main metallogenetic stage vary from 180℃ to 260℃ . Metallogenic depth is 1. 0 km. Ore fluid density ranges from 0.65 g/cm3 to 0.9 g/cm3 and the salinity w(NaCleq) ranges from 1.74% to 9.08% , averagely 5.33% . The ore deposit belongs to the structure-controlled alteration rock-type gold deposit. The ore deposit was formed in a ductile-brittle shear zone and resulted from a mixture of low salinity, low density, mesothermal and epithermal hydrothermal fluids cycling at the shallow part of the shear zone. The ore deposit is similar to the orogenic gold deposit in geological and geochemical characteristics, its genetic type can therefore be assigned to the epizonal orogenic subtype defined by Groves, and its industrial type can be assigned to the altered cataclastic-rock type. The formation of the Xiaoshuijing gold deposit experienced four stages as follows: ① the formation of ore source bed by original

  12. Gold in the Brunswick No. 12 volcanogenic massive sulfide deposit, Bathurst Mining Camp, Canada: Evidence from bulk ore analysis and laser ablation ICP-MS data on sulfide phases

    McClenaghan, Sean H.; Lentz, David R.; Martin, Jillian; Diegor, Wilfredo G.


    The 329-Mt Brunswick No. 12 volcanogenic massive sulfide deposit (total resource of 163 Mt at 10.4% Zn, 4.2% Pb, 0.34% Cu, and 115 g/t Ag) is hosted within a Middle Ordovician bimodal volcanic and sedimentary sequence. Massive sulfides are for the most part syngenetic, and the bulk of the sulfide ore occurs as a Zn-Pb-rich banded sulfide facies that forms an intimate relationship with a laterally extensive Algoma-type iron formation and defines the Brunswick Horizon. Zone refining of stratiform sulfides is considered to have resulted in the development of a large replacement-style Cu-rich basal sulfide facies, which is generally confined between the banded sulfide facies and an underlying stringer sulfide zone. Complex polyphase deformation and associated lower- to upper-greenschist facies regional metamorphism is responsible for the present geometry of the deposit. Textural modification has resulted in a general increase in grain size through the development of pyrite and arsenopyrite porphyroblasts, which tend to overprint primary mineral assemblages. Despite the heterogeneous ductile deformation, primary features have locally been preserved, such as fine-grained colloform pyrite and base and precious metal zonation within the Main Zone. Base metal and trace element abundances in massive sulfides from the Brunswick No. 12 deposit indicate two distinct geochemical associations. The basal sulfide facies, characterized by a proximal high-temperature hydrothermal signature (Cu-Co-Bi-Se), contains generally low Au contents averaging 0.39 ppm ( n = 34). Conversely, Au is enriched in the banded sulfide facies, averaging 1.1 ppm Au ( n = 21), and is associated with an exhalative suite of elements (Zn-Pb-As-Sb-Ag-Sn). Finely laminated sulfide lenses hosted by iron formation at the north end of the Main Zone are further enriched in Au, averaging 1.7 ppm ( n = 41) and ranging up to 8.2 ppm. Laser ablation inductively coupled plasma-mass spectrometry (ICP-MS) analyses of

  13. Research on flotation process of micro-fine particle copper-zinc ores containing gold and silver and high content of sulfur%含金银高硫微细粒铜锌矿石浮选工艺试验研究

    万宏民; 吴天骄; 靳建平


    The useful mineral particles in one gold and silver contained copper-zinc ore are micro-fine with high content of sulfur,chalcopyrite is closely related to sphalerite,galena,and arsenopyrite,and the content of sulfur is as high as 21.44%.In this paper,according to the characteristics of the ore properties,five processes are explored inclu-ding selective flotation of copper and zinc,the flotation capacity of copper and zinc,the flotation capacity of copper, zinc and sulfur,mixed flotation of copper and zinc-regrinding of copper and zinc concentrates-separation of copper and zinc,mixed flotation of copper,zinc and sulfur-regrinding of concentrates-separation of copper,zinc and sulfur. The results show that the process of mixed flotation of copper,zinc and sulfur-regrinding of concentrates-separation of copper,zinc and sulfur is well suited for the treatment of the ore with good technical indexes;at the same time it a-chieves good technical indexes with sulfide concentrates( gold and silver roughing concentrates) subject to metallurgi-cal treatment method.%某含金银高硫微细粒铜锌矿石中有用矿物粒度微细,黄铜矿与闪锌矿、方铅矿、毒砂关系密切,且硫高达21.44%。针对该矿石性质特点,试验探索了铜锌优先浮选、铜锌等可浮浮选、铜锌硫等可浮浮选、铜锌混浮—铜锌精矿再磨—铜锌分离、铜锌硫混浮—精矿再磨—铜锌硫分离等5种选别流程。试验结果表明:铜锌硫混浮—精矿再磨—铜锌硫分离流程适宜处理该矿石,其技术指标较好;同时,硫精矿(金银粗精矿)采用湿法工艺进行处理,也取得了良好的技术指标。

  14. Element geochemical characteristics of No.Ⅱ ore body of the Xiongcun porphyry copper-gold deposit in Tibet%西藏雄村斑岩铜金矿床Ⅱ号矿体元素地球化学特征及其指示意义

    黄勇; 唐菊兴; 丁俊; 郎兴海; 李志军; 张丽


    雄村铜金矿是冈底斯成矿带上新发现的岛弧型斑岩铜金矿床,矿床由3个矿体组成,Ⅱ号矿体位于Ⅰ号矿体北西侧3km处.Ⅱ号矿体中铜、金、银矿化主要分布在早期钾-硅酸盐化带以及绢云母白云母-石英硫化物带中,早期钾-硅酸盐化的典型矿物组合为黑云母+磁铁矿±钾长石+黄铜矿+黄铁矿,热液磁铁矿含量较高.元素空间分布特征以及相关性分析表明,Cu和Au、Ag呈显著正相关,黄铜矿是Au和Ag的主要载体,分布在矿体中心.Cu与K、Rb呈正相关,而与Na呈负相关的特点表明矿化与钾质交代关系密切,晚期矿化以分布在外围的细脉状、脉状方铅矿和闪锌矿化为主.由矿体中心向外,与矿化有关的16种元素构成Cu、Au、Ag、K、Rb、Ba-Mo-Co、Ni-Pb、Zn、Mn、Ag、Sb-Na元素分带,元素带状分布特征与蚀变矿化分带吻合.分布在外围的Na同时受钾质交代过程中Na元素向外迁移作用以及早期深部高温环境下的钠质-钙质蚀变共同控制.元素空间分带特征与蚀变与矿化分带机理类似,受热液流体演化、运移、温压条件和原岩组分等综合因素控制,分带特征对今后的找矿与勘探工作具有一定的指示意义.%The Xiongcun copper-gold deposit is an island arc porphyry copper-gold deposit newly discovered in the Gangdise metallogenic belt. It consists of three ore bodies. No. Ⅱ ore body is located 3 km northwest of No. I ore body. Cu, Au, and Ag mineralizations occur in early K-silicate alteration zone and sericite-muscovite-quartz-sulphide zone. Early K-silicate alteration is characterized by biotite + magnetite ± K-feldspar + chalcopy-rite+ pyrite, and is rich in magnetite. Element distribution characteristics and correlation analysis show that Cu is well correlated to Au and Ag. Au- and Ag-bearing chalcopyrite is mainly distributed at the center of the ore deposit. Cu is positively related to K, Rb and negatively related to Na

  15. Sulphur Isotope Compositions of Shibaqinghao Gold Deposit in Central Inner Mongolia, China

    Zhang Hongying; Liu Xiang


    Shibaqinghao gold deposit is situated in the western part of the northern margin of the North China Craton. It is controlled by an E - W trending tectonic zone that is located in the middle unit of Dongwufenzi group which consists of a sequence of greenschist - facies metamorphic rocks in an Archean greenstone belt.In Shibaqinghao gold deposit there are two types of gold ore, a mylonite ore and a quartz vein ore. Mylonite ore bodies were formed during ductile shearing stage in the Early Proterozoic, whereas quartz vein ore bodies might have been formed in the Mesozoic time.Pyrite accompanied with native gold in the mylonite ore has sulpfur of which δ34S values range from - 5.8 to + 0.8 per mil, similar to the values of mantle- derived sulphur. These data suggest that gold in the mylonite ore be derived from the country rocks which originated directly in the upper mantle.Pyrite in quartz vein ore has the δ34 S values between + 3.0 and + 11.0 per mil, similar to the values of some granitic rocks. These facts indicate that the gold in the quartz vein ore is related to some granitic magma generated in the crust.This study revealed that two different mineralization occurred at different geological times and in different environments but in the same place, resuling in the Shibaqinghao gold deposit.

  16. Geological significance of componential characteristics of pyrite from Shibaqinghao gold deposit in central Inner Mongolia, China

    Yihong Liang; Hongying Zhang; Yanhua Ma


    There are two types of gold ore in Shibaqinghao gold deposit, mylonite ore and quartz vein ore. Pyrite accompanying with native gold in mylonite ore has Fe from 43.66 to 45.32 wt% and S from 52.64 to 53.55 wt%. It is clear that this kind of pyrite is poor in both sulphur and iron. That means that the mylonite ore may be related to metamorphic water. Pyrite in the quartz vein ore has Fe from 44.38 to 45.30 wt% and S from 53.08 to 54.00 wt%. It means that this kind of pyrite is poor in iron but rich in sulphur, while the quartz vein ore may be related to magma water.

  17. 桂西南的两类大型断裂构造与金矿成矿──以凭祥地区为例%Two kinds of large-scale fault structures and gold ore mineralization—An example from Pingxiang region

    梁金城; 冯佐海; 陈懋弘


    There are two kinds of large-scale fault structures in the southwestern Guangxi, one is the onward outspreaded imbricate Pingxiang thrust-nappe tectonics,with strike between 25°~40°, dip to SE, dip angle between 20°~30°, thrust direction towards 310±. It has an obvious zoning system with e=-33.3%. εγ=66.7%, S >5 600 m, and it was formed as a result of the fault-thrust movement of the Indo-Chinese-Yanshan epoch. The other is Pingxiang-Dongmen fault.It stikes at 45°~80°and dips generally southward with dip angles between 50°~80°, it was a tension fault during the Hercynian epoch, and was transformed into a dextral strike-slip one during the Indo-Chinese-Yanshan epoch with a mixed product of mylonite-cataclasite. The results of the finite strain measurements show that k=1.5, γ=3~4, X∶Z=10∶1~20∶1, paleostress Δσ is between 100~120 MPa. Gold ore is related to the stike-slip faults, with main faults directing the ore-forming flow while the secondary NE faults control the ore bodies. Gold ore mineralization is usually existed in the altered lava cataclasite, and T1 medium-acidic volcanic lava is an important layer to look for gold ore deposits. Supergene oxidation helps secondary ore enrichment.The gold enrichment variation in the thrust-nappe tectonics is as follows:front zone 1.0×10-9,middle zone 1.94×10-9,root zone 2.18×10-9,the value increases from the front zone to the root zone,and this will have to be paid attention to in our geological exploration around the root zones.%桂西南发育两类大型断裂构造:(1)逆冲推覆构造为前展式、叠瓦状构造,走向25°~40°,倾向SE,倾角20°~30°,逆冲方向310°±,分带明显;e=-33.3%,εγ=66.7%,s>5 600 m,为印支—燕山早期冲断-推覆成因。(2)东门断裂为一长寿深断裂,走向45°~80°,总体南倾,倾角50°~80°,海西期为拉张控相,印支期以后为右旋走滑,先后形成糜棱岩

  18. 滇西北衙多金属矿田矿床成因类型及其与富碱斑岩关系初探%Genetic types and the relationship between alkalirich intrusion and mineralization of Beiya gold-polymetallic ore field, western Yunnan Province, China

    和文言; 喻学惠; 莫宣学; 和中华; 李勇; 黄行凯; 苏纲生


    北衙金多金属矿田是与金沙江-哀牢山新生代富碱斑岩有关的成矿作用的典型代表之一,近年来在矿产勘查方面又有重大突破,金已达到超大型矿床,伴生铁、铜、银、铅、锌也达到了大-中型矿床规模.本文基于野外观察与室内研究,结合前人研究成果,对北衙多金属矿的成因类型,富碱斑岩与成矿作用的关系及成矿机制进行了系统总结,对与成矿相关的富碱斑岩进行了主量元素及锆石LA-ICP-MS的测试,探讨了铁矿的成因.研究表明,矿田原生金属矿床可分为:斑岩型铜金矿化,夕卡岩型铁、金、铜、铅、锌矿化,爆破角砾岩筒中的铁、金、铅、锌矿化以及热液型金、银、铅、锌矿化.其中夕卡岩型和热液型矿床是该区最主要的成矿类型.新生代富碱斑岩(石英正长斑岩)的年龄分别34.92±0.66Ma和36.24±0.63Ma.属于钾质碱性岩系列.它不仅为含矿流体的上升提供了动力和热能,而且还是成矿物质和成矿流体的主要来源,因此形成以斑岩体为中心,由斑岩型、夕卡岩型、热液型等矿床构成的一个连续的成矿系统.钾质碱性岩及矿床是在碰撞造山走滑构造系统深部壳幔相互作用的产物.本区岩体接触带中发育大量由菱铁矿和磁铁矿组成的铁矿体,其中大部分的磁铁矿是一种具有赤铁矿的板状晶或聚片双晶假象的穆磁铁矿.时磁铁矿和菱铁矿形成条件的分析表明,磁铁矿和菱铁矿主要是在碱性环境下交代含铁夕卡岩矿物形成的.当热液中H+的浓度降低时,赤铁矿被还原为磁铁矿,但仍保留了赤铁矿的晶形,于是成为穆磁铁矿.由此推测,本区成矿作用是在成矿流体及夕卡岩化交代作用长时间反复持续进行的条件下发生的,这可能是本区得以形成巨量金属堆积的重要原因之一.%The Beiya gold-polymetallic ore field is one of the typical deposits related to the Jinshajiang

  19. Processing of lateritic ores

    Collier, D.E.; Ring, R.J. [Environment Division, Australian Nuclear Science and Technology Organisation, Menai, New South Wales (Australia); McGill, J.; Russell, H. [Energy Resources of Australia Ltd., Ranger Mine, Jabiru, Northern Territory (Australia)


    Highly weathered or lateritic ores that contain high proportions of fine clay minerals present specific problems when they are processed to extract uranium. Of perhaps the greatest significance is the potential of the fine minerals to adsorb dissolved uranium (preg-robbing) from leach liquors produced by processing laterites or blends of laterite and primary ores. These losses can amount to 25% of the readily soluble uranium. The clay components can also restrict practical slurry densities to relatively low values in order to avoid rheology problems in pumping and agitation. The fine fractions also contribute to relatively poor solid-liquid separation characteristics in settling and/or filtration. Studies at ANSTO have characterised the minerals believed to be responsible for these problems and quantified the effects of the fines in these types of ores. Processing strategies were also examined, including roasting, resin-in-leach and separate leaching of the laterite fines to overcome potential problems. The incorporation of the preferred treatment option into an existing mill circuit is discussed. (author)

  20. New Understanding of the Source of Ore-Forming Material and Fluid in the Shanggong Gold Deposit, East Qinling%东秦岭上宫金矿成矿流体与成矿物质来源新认识

    胡新露; 何谋春; 姚书振


    上宫金矿床位于华北克拉通南缘的熊耳地体之中,是典型的构造蚀变岩型金矿.本文对上宫金矿的同位素地球化学资料进行了系统分析和综合研究,对其成矿物质和成矿流体的来源取得了一些新的认识.氢-氧-碳同位素体系研究表明,成矿流体并非来自燕山期岩浆热液,也不是来自于太华群或者官道口群和栾川群的变质脱水作用,而主要来自深部地幔或者由幔源岩浆派生,并在成矿的过程中逐渐向大气降水演化.硫-铅-锶同位素体系指示成矿物质为壳幔混合来源,地幔和太华群可能均提供了部分成矿物质.印支期华北与扬子板块发生碰撞对接时导致了强烈的壳幔相互作用,并驱动深部流体向上运移,上官金矿正是在这种构造背景下形成的.%The Shanggong gold deposit is typical of tectonic altered rock type gold deposit occurring in the Xiong 'er terrane, southern margin of the North China Craton. The isotopic data about this deposit were systematically analyzed and comprehensively summarized, and some new understanding about the source of ore-forming material and ore-forming fluid were achieved. The D-O-C isotopic system shows that the ore-forming fluid derived neither from the Yanshanian magmatic-hydrothermal solution nor from devolatilization of the Taihua, Guandaokou and Luanchuan groups, but from mantle or mantle-derived magma, and it evolved to meteoric water with development of mineralization. The S-Pb-Sr isotope ratios imply a mixing origin of the materials from crust and mantle, with the mantle and Taihua Group likely contributing partial metallogenic materials. In the Indochina period, the collision of the Yangtze and North China plates may result in the strong interaction between the crust and upper mantle, and drive the deep seated fluid to migrate upward. It is under this tectonic background that the Shanggong gold deposit formed.

  1. Characteristics of the ore-forming fluid of typical gold deposits in Xiaoshan area of Henan and their enlightenment to further prospecting works%河南省崤山地区典型金矿床的成矿流体特征及其对进一步找矿工作的启示

    徐文超; 王通; 常云真; 周奇明; 贾慧敏; 赵留升


    Xiaoshan area is located inside the middle-west part of Xiaoqinling-Xiaoshan-Xiong’ershan-Waifang-shan Au-Ag-Mo polymetallic metallogenic belt in western Henan.However,the measured reserves of gold ores is far less than that of Xiaoqinling area and eastern Xiong’ershan area.Therefore,the prospecting po-tential in Xiaoshan area attracts great attention of related industrial sectors.Combined with previous work, this paper put forth the theory that the gold ores in the area were predominated by fracture zone alteration rock type and quartz vein type.According to the analysis of typical deposits,the paper concluded that the mineralization of gold ores could be divided into four stages from early to late:(1)quartz-pyrite (arsenopy-rite)stage,(2)pyrite-quartz stage,(3)quartz-polymetallic sulfide stage,and (4)quartz-carbonate stage. Among the four stages,stage (2)and (3)are the main stages of mineralization.The author conducted analy-sis on the content,homogenization temperature and S-H-O-Pb isotope composition of the fluid inclusions in the quartz crystals in each ore-forming stage.It indicates that the fluid was CO 2-rich aqueous fluid with nu-merous dissolved Na+ and Ca2 + ions.The homogenization temperature of fluid inclusions ranges from 243℃to 285℃,and it suggests that the gold deposits in Xiaoshan area are mainly intermediate temperate hydro-thermal deposits being short of fluid inclusions of high temperature stage.The δ34 S value of metal sulfide ranges from -0.5‰ to 5.4‰ and it shows the characteristics of deep source sulfur.And its δ1 8 O H2 O value ranges from 0.1‰ to 9.4‰ and δ1 8 D value ranges from - 134.9‰ to 24.3‰,and it shows that the ore-forming fluid occurs mainly as magmatic water with lesser atmospheric precipitation and metamorphic water. Based on the comparison between outcrop area of granitic intrusive rocks in Xiaoshan area and that in Xiao-qinling area,it appears that the unsatisfactory prospecting results in Xiaoshan area

  2. Mineralogical-Geochemical Peculiarities of Ores in Pyritaceous Fields of Filizchai Type in the Greater Caucasus



    Full Text Available Pyritaceous fields of the south slope of the Greater Caucasus confined to the Lower-Middle Jurassic sandy clayey deposits are: polygenic polychrone formations which were formed by a complex of hydrothermal sedimentary, hydrothermal metasomatic and hydrothermal metamorphogenic processes of ore formation. Filizchai pyritaceous polymetallic field is the largest in the region and can be characterized by diversity of texture-mineralogical types of ores, rich mineral composition and with geochemical spectrum. Some of the admixture components (Cd, In, Tl, Ga, Ge, Se, Hg are only in isomorphic forms in ores, others (Te, Bi, Au, Ag, Co, Sn, As along with it characterize in their own minerals. The Co is mainly concentrated in pyrite, pyrrhotine; Ag, Bi and also Te – in galenite and chalcopyrite; Se – in pyrite, pyrrhotine and galenite; in sphalerite (mainly in marmatite and chalcopyrite; Cd, Ga, Ge – in sphalerite, mainly in cleiophane; Au – in pyrite and chalcopyrite; Tl – in galenite and colloform pyrite. In all sulphides selenium prevails over tellurium (excepting the late chalcopyrite and cobalt over nickel. Maximum amount of cobalt is confined to pyrite from pyritaceous polymetallic ores and late generation of pyrrhotine. The nature of the connection between chemical elements in ores coordinates with determined stages of minerals formation. The main productive stage of ore formation bringing the main mass of gold, silver, rare and other precious components of ores are sulphosalt polymetallic stage of sulphur ploymetallic stage. Comparative analysis of absolute content of gold, silver and values of gold-silver relation in pyrite fields ores of region with appropriate values in meteorite standard indirectly indicates the relationship between gold-silver mineralization and assimilation crust source.

  3. Complexing and hydrothermal ore deposition

    Helgeson, Harold C


    Complexing and Hydrothermal Ore Deposition provides a synthesis of fact, theory, and interpretative speculation on hydrothermal ore-forming solutions. This book summarizes information and theory of the internal chemistry of aqueous electrolyte solutions accumulated in previous years. The scope of the discussion is limited to those aspects of particular interest to the geologist working on the problem of hydrothermal ore genesis. Wherever feasible, fundamental principles are reviewed. Portions of this text are devoted to calculations of specific hydrothermal equilibriums in multicompone

  4. The Extraction and Analysis of Iron Alteration Information Based on SPOT Data for Mineral Prediction: A Case Study of the Longnan Gold Ore District%基于SPOT数据的铁化蚀变信息提取及找矿应用研究——以陇南金矿区为例

    李智峰; 朱谷昌; 张建国; 刘欢; 胡杏花


    针对遥感方法找矿预测问题,以甘肃陇南金矿区为例,对基于SPOT数据的铁化蚀变信息提取及其在找矿预测中的应用进行了研究.在分析研究区的地质背景资料及其围岩蚀变类型的基础上,利用SPOT 5卫星遥感数据,经过多种图像处理,提取了与金矿密切相关的铁化蚀变异常信息,探索了利用中高分辨率卫星SPOT数据提取遥感蚀变异常信息的可行性.研究表明,相对于ETM、ASTER等数据,虽然SPOT不具有更宽的光谱范围和更高的光谱分辨率,但是针对特定区域的特定任务,SPOT数据仍然能够发挥应有的作用.%Taking the Longnan gold ore district in Gansu Province as the study area, this paper carried out the study of extracting iron alteration information from satellite - based remote sensing images from SPOT data. Based on analyzing the geological background and rock alteration types, the authors used SPOT 5 satellite remote sensing images and, by utilizing a variety of image processing methods, extracted the iron alteration information closely relat I to gold mineralization and explored the feasibility of extracting alteration information from moderate and high resolution satellite data. The results show that, in comparison with ETM, ASTER and other satellite data, SPOT does not have a broader spectral range and higher spectral resolution, but can play an effective role in carrying out some specific tasks in particular area.

  5. 烟台市牟平区某金矿地面塌陷特征及防治对策研究%Study on the Characteristics of a Gold Ore Surface Collapse in Muping District of Yantai City and Some Prevention Countermeasures

    孟盼盼; 王经; 吕宝平; 赵菲


    The article introduces the basic characteristics and geological environmental conditions of surface collapse of a gold ore in Muping District of Yantai city as well as analyzes the controlling factors of the surface collapse.Then the article predicts its development tendency and proposes the corresponding countermeasures according to the characteristics of surface collapse.T his article introduces the basic methods of investigating and analyzing the mining collapse and proves that the surface collapse caused by mining is closely related to the geological environmental conditions.%介绍了烟台市牟平区某金矿地面塌陷的基本特征和地质环境条件 ,分析了该地面塌陷的控制因素 ,预测了其发展趋势 ,并根据地面塌陷特征提出了相应的防治对策.说明了调查分析采空塌陷的基本方法及采矿所引起的地面塌陷与地质环境条件有着密切关系.

  6. Hunting for Iron Ore Bargains


    One of China’s leading steel mills has turned to smaller mines for long-term, lowcost iron ore supplies china’s oldest steel producer is looking to South America to fulfill its iron ore needs in the face of rising prices from

  7. 酒石酸络合掩蔽锑-氢醌容量法测定锑矿石样品中的常量金%Determination of Gold in Antimony Ores by Hydroquinone Volumetric Method with Antimony Tartrate as Complexing and Masking Agent

    张志刚; 刘凯; 陈泓; 冯瑞; 黄劲; 魏晶晶; 詹宝


    The traditional method of determining gold in antimony ores commonly includes sample digestion by aqua regia,preconcentration of gold by activated carbon,and measurement by hydroquinone volumetric technique. The traditional method suffers from the high contents of antimony,sulfur,arsenic,and mercury. Sulfur,arsenic, mercury,and carbon can be removed by stepwise heat,but antimony cannot be removed. In this study,tartaric acid is added to eliminate the interference of antimony. Adding tartaric acid to aqua regia during sample digestion can prevent proteolysis of antimony compounds as the acidity or temperature decreases. This step can ensure that the antimony quantity is less than 0. 3 mg after the ashing of activated carbon that has adsorbed gold. After being ashed,tartaric acid is again added in aqua regia to dissolve gold,eliminating the interference of antimony on gold during hydroquinone volumetric determination of gold. The proposed method suggests adding tartaric acid at the sample digestion stage is simple and rapid relative to the method of antimony elimination by hydrobromic acid and hydrochloric acid. The relative standard deviation of natural sample analysis is less than 5% and standard-addition recovery is 92 . 0% -107 . 0%.%应用王水溶样-活性炭富集金-氢醌容量法测定高品位锑矿石的金量时,通常受到较高含量的锑硫砷汞等元素的干扰,硫砷汞碳及有机质可以通过阶梯升温焙烧去除,但是对锑则无明显去除作用。本研究在相关实验环节通过加入酒石酸使锑的干扰问题得到解决,包括:王水溶矿时加入酒石酸络合锑,防止锑的化合物在酸度或温度降低时水解,保证吸附金的活性炭灰化后的锑量小于0.3 mg;活性炭灰化除碳后,用王水溶解金时再加入酒石酸,消除了氢醌容量法滴定过程中少量锑的干扰。本方法只需在溶矿时加入一定量酒石酸,与氢溴酸除锑、盐酸等除锑方

  8. Temporal and spatial distribution of Au-Ag polymetallic ore deposits and source of ore-forming materials in the Zhangjiakou-Xuanhua mantle-branch metallogenetic zone


    The Zhangjiakou-Xuanhua area is a mineral resource-concentrated area for gold-silver polymetallic ore deposits. The temporal and spatial distribution and origin of mineral resources have been argued for a long time. Based on the comprehensive studies of geochronology and sulfur, lead, oxygen, carbon and noble gas isotopes, it is considered that the temporal and spatial distribution of mineral resources in this area is obviously controlled by the Zhangjiakou-Xuanhua mantle branch structure, as is reflected by the occurrence of gold deposits in the inner parts and of Ag-Pb-Zn polymetallic ore deposits in the outer parts. The mineralization took place mainly during the Yanshanian period. Ore-forming materials came largely from the deep interior of the Earth, and hydrothermal fluids were derived predominantly from Yanshanian magmatism.

  9. Multi-information integrated exploration methods and ore-prospecting model of the Chelsea East gold deposit in Mutawatawa area,Zimbabwe%津巴布韦 Mutawatawa 地区 Chelsea East 金矿床多元信息综合找矿方法及找矿模型

    闫红圃; 刘文斌; 程兴国


    笔者通过津巴布韦北东部 Mutawatawa 地区 Chelsea East 金矿床的发现,提出了适合于南部非洲亚热带大陆性半干旱气候区的多元信息综合找矿方法,即以成矿地质特征研究为前提,融合了地质、地球物理、地球化学和工程验证等多种技术手段的综合找矿过程。实践证明,综合找矿具有经济、快捷和找矿效果显著等特点。在此基础上,通过对各种找矿方法的相互配合和分析研究,提出了适合于本地区的金综合找矿模型,为本地区乃至南部非洲地区的金多金属矿找矿提供了重要的指导意义。%Based on discovering the Chelsea East gold deposit in northeastern Mutawatawa of Zimbabwe, the authors put forward the suitable multivariate⁃information comprehensive prospecting methods for subtropical continental semi⁃arid climate of South Africa. The methods combine a variety of geological, geophysical, geochemical and engineering means for comprehensive prospecting process on the premise of the study of ore⁃forming geological characteristics. Practice has proved that the comprehensive prospecting has remarkable e⁃conomic and prospecting effect besides its rapidness. Based on an integrated analysis of prospecting methods, the authors present a comprehensive prospecting model suitable for gold exploration in this region, which has important guiding significance for gold poly⁃metallic ore prospecting work in this region or even in whole South Africa.

  10. Use of ferricyanide for gold and silver cyanidation



    Low gold and silver leaching kinetics has been commonly observed in traditional gold-silver cyanidation process, especially in heap leaching and in situ leaching operations. The different mineralogy of gold and silver in the ores is suspected to be the main reason, e.g., the occurrence of low solubility acanthite (Ag2S) typically results in low overall silver extraction. Due to the low solubility of oxygen in cyanide solution, the reactivity and availability of oxidant is believed to be the critical limitation for gold and silver dissolution. The use of ferricyanide as the auxiliary oxidant for gold and silver cyanidation has been examined. The rotating disc test results prove the assistant effect of ferricyanide on increasing the dissolution rate of gold and silver. The potential use of ferricyanide in gold/silver cyanidation process is proposed based on the leaching results of actual ores.

  11. Leaching behavior of butanedionedioxime as gold ligand


    Butanedionedioxime, a small organic compound with low-toxicity and good chemical stability, has been proposed as an effective gold ligand in gold extraction. The result of experiment shows that: 1) highly effective gold lixiviantcan be composed of butanedionedioxime (BDM) with many oxidants, especially potassium permanganate; 2)in the leaching system of BD M- K M nO4 the suitable Ox/Lig(ratio of oxidants to gold ligands) tange is 0.20 ~ 0. 50, optimally 0.25 ~0.45 at the pH range of 7 ~ 11; 3) BDM-KMnO4 extraction of gold from an oxide ore is similar to cyanide(cyanide-O2)extraction, but the leaching rate of gold by BDM-KMnO4 is faster than that by cyanide-O2; 4) gold may readily be recov-ered by carbon adsorption and zinc precipitation

  12. Dual origins of Xiaoqinling gold-bearing quartz veins: Fluid inclusion evidence


    Fluid inclusion research in Archean metamorphic rocks, Yanshanian granite and gold-bearing quartz veins shows that regional metamorphic fluids are high temperature and high saline, Yanshanian post-granitic fluids are CO2-bearing low saline, and ore-forming fluids are also CO2-rich low saline. In gold-barren/free parts of quartz veins in gold deposits, daughter mineral-bearing high saline inclusions related with metamorphic fluids remained. This proclaims quartz veins hosting gold ores might have been formed in early metamorphism, and overlapped or mineralized by late Yanshanian gold-bearing fluids.

  13. 振动给矿机在河台金矿选矿厂的改造与设计%Reformation and design of vibrofeeder in Hetai gold mine ore processing plant



    针对河台金矿选矿厂原矿仓至颚式破碎机使用板式给矿机存在的一些问题,提出了选矿厂给矿改造方案.详述了改造方案的设备选型及技术参数的设计计算过程.河台金矿选矿厂振动给矿机替代板式给矿机技术改造实践表明,技术改造提高了选矿处理能力40%,给矿均匀,且对颚式破碎机工况冲击小,维护维修简易,能耗低,取得了很好的应用效果.%A reformation design was put forward in light of the problems occurring in the plate feeder of jaw crusher. The equipment selection and technical parameters calculation process were introduced in detail. The replacement of plate feeder by vibrofeeder in the processing plant of Hetai gold mine results in a 40 % increased treatment capability. Besides, the feeder consumes less energy, feeds evenly, doing little impact to the crusher, and is convenient for maintenance, achieving good application outcome.

  14. Geological and geochemical character and genesis of the Jinlongshan-Qiuling gold deposits in Qinling orogen: Metallogenic mechanism of the Qinling-pattern Carlin-type gold deposits

    张复新,陈衍景,李超Department; of; Geology,; Peking; University,; Beijing; 100871,; China; ,张静Department; of; Geology,; Peking; University,; Beijing; 100871,; China; ,马建秦,李欣Department; of; Geology,; Peking; University,; Beijing; 100871,; China


    The Qinling Carlin-type gold deposit belt is the second largest Carlin-type gold ore concentrated area in the world and occurs in Mesozoic intracontinental collisional orogen, contrasting to the Carlin-type gold deposits in the Basin and Range province in Cenozoic active continental margin of West America. With ore-forming ages focussed at the range of 197.45-129.45 Ma, its metallogenic geodynamic background was the decornpression-pyrogenation regime at the transition stage from collisional compression to extension, indicating that gold mineralization synchronized with the Mesozoic continental collision. Geochemical studies discover that ore fluids and materials mainly came from the Hercynian-lndosinian tectonic layer. Mesozoic intracontinental subduction of Hercynian-lndosinian association along the Shuanghe-Gongguan fault led to the formation of Jinlongshan-Qiuling gold deposits. Accordingly, the tectonic metallogenic model is established for Qinling-pattern Carlin-type gold deposits.

  15. Microbial reduction of iron ore

    Hoffmann, Michael R.; Arnold, Robert G.; Stephanopoulos, Gregory


    A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry.

  16. Gold Rush!

    Brahier, Daniel J.


    Describes a mathematical investigation of gold--how it is weighed, stored, used, and valued. For grades 3-4, children estimate the value of treasure chests filled with gold coins and explore the size and weight of gold bars. Children in grades 5-6 explore how gold is mined and used, and how the value of gold changes over time. (PVD)

  17. Porphyry-copper ore shells form at stable pressure-temperature fronts within dynamic fluid plumes.

    Weis, P; Driesner, T; Heinrich, C A


    Porphyry-type ore deposits are major resources of copper and gold, precipitated from fluids expelled by crustal magma chambers. The metals are typically concentrated in confined ore shells within vertically extensive vein networks, formed through hydraulic fracturing of rock by ascending fluids. Numerical modeling shows that dynamic permeability responses to magmatic fluid expulsion can stabilize a front of metal precipitation at the boundary between lithostatically pressured up-flow of hot magmatic fluids and hydrostatically pressured convection of cooler meteoric fluids. The balance between focused heat advection and lateral cooling controls the most important economic characteristics, including size, shape, and ore grade. This self-sustaining process may extend to epithermal gold deposits, venting at active volcanoes, and regions with the potential for geothermal energy production.

  18. Source and location mechanism for lode gold deposits hosted in metamorphic rocks in northeastern Hunan, China


    For understanding the source and location mechanism of lode gold deposits hosted in metamorphic rocks in northeastern Hunan, the authors analyzed the REE (rare earth elements) in ores and their host rocks, metallogenic elements in host rocks near and distant from the ore-bodies, and characteristics of ore-controlling structures, and deduced their genetic implication. Their geochemical features of REE and metallogenic elements suggest that they are formed by mobilization of dispersed metallogenic materials in Lengjiaxi Group of Middle Proterozoic during deformation and metamorphism process, mainly in Wulingian period. From the attributes of ore-controlling structures and regularity of location of gold metallization, it is concluded that the location of gold deposits is closely related to reverse shearing. Ore-forming fluids are focused on the secondary faults and extension fractures of reverse shear zones of nearly EW strike by stress-driven diffusion and seismic pumping.

  19. Some features of mineralization and magnetism of the Kara ore field according to Pb-isotopic data

    Spiridonov, A.M.; Fefelov, N.N.; Petrovskaya, S.G.; Gnilusha, V.A.; Solodyankina, V.N.


    The genetic nature of the Kara are field, being a part of the gol - molybdenum zone of the East Transbaikal region, is considered. The lead isotopic composition of mineralization represented by veins, ore and metasomatic zones with vein-impregnate mineralization of gold-sulphide-quartz formation is measured. Investigations of the lead isotopic composition permit to connect the mineralization of the Kara ore field with magmatites of the shoshonitelatite series.

  20. Uranium mill ore dust characterization

    Knuth, R.H.; George, A.C.


    Cascade impactor and general air ore dust measurements were taken in a uranium processing mill in order to characterize the airborne activity, the degree of equilibrium, the particle size distribution and the respirable fraction for the /sup 238/U chain nuclides. The sampling locations were selected to limit the possibility of cross contamination by airborne dusts originating in different process areas of the mill. The reliability of the modified impactor and measurement techniques was ascertained by duplicate sampling. The results reveal no significant deviation from secular equilibrium in both airborne and bulk ore samples for the /sup 234/U and /sup 230/Th nuclides. In total airborne dust measurements, the /sup 226/Ra and /sup 210/Pb nuclides were found to be depleted by 20 and 25%, respectively. Bulk ore samples showed depletions of 10% for the /sup 226/Ra and /sup 210/Pb nuclides. Impactor samples show disequilibrium of /sup 226/Ra as high as +-50% for different size fractions. In these samples the /sup 226/Ra ratio was generally found to increase as particle size decreased. Activity median aerodynamic diameters of the airborne dusts ranged from 5 to 30 with a median diameter of 11 The maximum respirable fraction for the ore dusts, based on the proposed International Commission on Radiological Protection's (ICRP) definition of pulmonary deposition, was < 15% of the total airborne concentration. Ore dust parameters calculated for impactor duplicate samples were found to be in excellent agreement.

  1. Origin of Gold—Bearing Fluid and Its Initiative Localization Mechanism in Xiadian Gold Deposit,Shandong Province

    邓军; 孙忠实; 等


    The composition of quartz inclusions and trace elements in ore indicate that gold-bearing fluid in the Xiadian gold deposit,Shandong Province,stemmed from both mantle and magma,belonging to a composite origin.Based on theoretical analysis and high temperature and high pressure experimental studies,gold-bearing fluid initiative localization mechanism and the forming environment of ore-host rocks are discussed in the present paper.The composite fluid extracted gold from rocks because of its expanding and injecting forces and injecting forces and flew through ore-conducive structures,leading to the breakup of rocks.The generation of ore-host faults and the precipitation of gold-bearing fluid occurred almost simultaneously.This study provides fur-ther information about the relationships between gold ore veins and basic-ultrabasic vein rocks and intermediate vein rocks,the spatial distribution of gold ore veins and the rules governing the migration of ore fluids.

  2. [Study of hydrogen cyanide activity in various working environment in gold-mining industry].

    Dedkova, L A; Dorogova, V B; Petrov, V F


    The study concerned an influence of saline content of liquid phase of crushed ore and presence or absence of solution blending on the process of cyanic hydrogen release in air of working area gold-mining industry.

  3. Numerical Modelling of Ore-forming Dynamics of Fractal Dispersive Fluid Systems

    邓军; 方云; 杨立强; 杨军臣; 孙忠实; 王建平; 丁式江; 王庆飞


    Based on an analysis of the fractal structures and mass transport mechanism of typical shear-fluid-ore formation system, the fractal dispersion theory of the fluid system was used in the dynamic study of the ore formation system. The model of point-source diffusive illuviation of the shear-fluid-ore formation system was constructed, and the numerical simulation of dynamics of the ore formation system was finished. The result shows that: (1) The metallogenic system have nested fractal structure. Different fractal dimension values in different systems show unbalance and inhomogeneity of ore-forming processes in the geohistory. It is an important parameter to symbolize the process of remobilization and accumulation of ore-forming materials. Also it can indicate the dynamics of the metallogenic system quantitatively to some extent. (2) In essence, the fractal dispersive ore-forming dynamics is a combination of multi-processes dominated by fluid dynamics and supplemented by molecule dispersion in fluids and fluid-rock interaction. It changes components and physico-chemical properties of primary rocks and fluids, favouring deposition and mineralization of ore-forming materials. (3) Gold ore-forming processes in different types of shear zones are quite different. (1) In a metallogenic system with inhomogeneous volumetric change and inhomogeneous shear, mineralization occurs in structural barriers in the centre of a shear zone and in geochemical barriers in the shear zone near its boundaries. But there is little possibility of mineralization out of the shear zone. (2) As to a metallogenic system with inhomogeneous volumetric change and simple shear, mineralization may occur only in structural barriers near the centre of the shear zone. (3) In a metallogenic system with homogeneous volumetric change and inhomogeneous shear, mineralization may occur in geochemical barriers both within and out of the shear zone.


    Košuth Marián


    Full Text Available The main processing interest of examined Zlatá Baňa polymetalic ores was focused on copper-lead-zinc minerals with precious metals and trace elements. Gold occurrin a native form or as an isomorphism in pyrite. The role of inclusions of own Ag-minerals was inflated by geologist, but a prevailing amount of silver is isomorphous in galena and argentotetrahedrite. Almost no possibility to concentrating discrete silver minerals was proved technologically. In galena, an interesting content of Se and Te was registered. Among trace elements, a higher content of cadmium folows exclusively the content of zinc in blende.

  5. Mineralization Types of Gold in Central Inner Mongolia, China

    Liang Yihong; Zhang Hongying


    There are four mineralization types of gold in Central Inner Mongolia: mylonite type, quartz vein type, quartzpotash- feldspar vein type and alteration type.Ore bodies of mylonite type were controlled by ductile shear zone. Both of ore and gangue minerals were undergone ductile deformation. Mineralization age is about 2040Ma and represents the metallogenetic process in deep tectonic level.There are three types of quartz veins differed from genesis mechanism. Small scaled, lens- shaped quartz veins formed during ductile shearing are found in mylonite ore bodies. Decation quartz veins are in the ore bodies of alteration type. Infiltration quartz veins are main gold- bearing bodies for some gold deposits such as Bainaimiao and Saiwusu gold mines. It also occurred in many other deposits from the middle Proterozoic to the Mesozoic.Quartz potash- feldspar veins are observed in the Palaeozoic and occurred in middle tectonic level.Gold deposits of alteration type such as Donghuofang and Saihudong occurred in shallow tectonic level of the Mesozoic.In short, from the Proterozoic to the Mesozoic, mineralization types varied from mylonite type to quartz potash- feldspar vein type and to alteration type. Gold - bearing quartz veins changed from syn - ductile - shearing quartz vein to infiltration vein and to decation quartz vein. Mineralization developed from deep to middle and to shallow level.

  6. Comparison of the native antimony-bearing Paiting gold deposit, Guizhou Province, China, with Carlin-type gold deposits, Nevada, USA

    Xie, Zhuo-Jun; Xia, Yong; Cline, Jean S.; Yan, Bao-Wen; Wang, Ze-Peng; Tan, Qin-Ping; Wei, Dong-Tian


    The Paiting gold deposit, Guizhou Province, China, has been regarded as a Carlin-type gold deposit by several researchers. Alteration and ore-related minerals from the Paiting deposit were examined, and results were compared with the Cortez Hills Carlin-type gold deposit, Nevada, USA. Similarities include the structural and stratigraphic controls on the orebodies in both deposits and the occurrence of invisible gold ionically bound in arsenian pyrite. Significant differences include the following: (1) The gold-bearing mineral in Nevada is arsenian pyrite. However, gold-bearing minerals in the Paiting deposit include arsenopyrite, arsenian pyrite, and trace pyrrhotite. Also, euhedral or subhedral gold-bearing arsenian pyrite at Paiting contains significantly less As, Cu, and Hg than gold-bearing pyrite from Nevada. (2) Alteration in the Paiting deposit displays significantly less decarbonatization. Instead, dolomite precipitation, which has not been described in Nevada deposits, is associated with deposition of gold-bearing sulfide minerals. (3) Stibnite and minor native antimony typify Paiting late-ore-stage minerals, whereas in Nevada, realgar, orpiment, and calcite are common late-ore-stage minerals. Precipitation of native antimony in the Paiting deposit reflects the evolution of a late-ore fluid with unusually low sulfur and oxygen fugacities. Some characteristics of the Paiting gold deposit, including formation of ore-stage dolomite and precipitation from CO2-rich ore fluids at temperatures in excess of 250 °C, are more typical of orogenic deposits than Nevada Carlin deposits. The presence of similarities in the Paiting deposit to both Carlin type and orogenic deposits is consistent with formation conditions intermediate to those typical of Carlin type and orogenic systems.

  7. Bismuth mineral inclusions in gold-bearing magnetite from the giant Beiya gold deposit, SW China: insights into mineralization process

    Zhou, Haoyang; Sun, Xiaoming


    Bismuth minerals are commonly found in a wide range of gold deposits and could offer valuable information on the process of gold mineralization. This is because Bi minerals always show immediate association with gold and are sensitive to chemical-physical variations (Afifi et al., 1988). Specifically, native bismuth has a melting point of 271°C and could melt at lower temperatures when gold is added (Okamoto et al,, 1983). It has been verified that Bi melt could efficiently scavenge gold from hydrothermal fluids (Tooth et al., 2008, 2011). The Beiya deposit, situated in the Sanjiang Tethyan tectonic domain in the southwestern China, is one of the largest gold deposits in China 10.4 Moz Au @ 2.47g/t). Located along the contacts between a 36 Ma quartz syenite porphyry and the Triassic limestones, the deposit contains abundant massive Au-bearing magnetite ores, which are considered as a product of skarn mineralization. However, the pivotal processes accounting for the huge accumulation of gold resource at Beiya area are poorly constrained. In the massive magnetite ores, abundant native gold was observed to be present as submicron-scale inclusions hosted by magnetite (Zhou et al., 2017). We also noted that abundant Bi minerals occur within these ores (Zhou et al., 2016), which provide critical clues to reveal the processes of gold mineralization. An assemblage of Bi minerals, composed of native bismuth, maldonite and bismuthinite, is present as tiny inclusions in these Au-bearing magnetite grains. Mineralogical study illustrates the encapsulation of native bismuth and maldonite as melts during magnetite growth, which is also supported by the ore-forming temperatures over 300°C derived from previous fluid inclusions study (He et al., 2016). Our thermodynamic modeling demonstrates that Bi melts scavenged gold from hydrothermal fluids. Subsequently, sulfidation of Bi melts resulted in precipitation of gold, which was captured by growing magnetite. We thus propose that

  8. Environmental Monitoring at the Nalunaq Gold Mine, South Greenland, 2011

    Bach, Lis; Asmund, Gert; Søndergaard, Jens

    This eighth environmental monitoring programme was conducted in the Nalunaq area, about 40 km from Nanortalik, South Greenland, from 29 August to 12 September 2011. The environmental monitoring program is conducted to trace and avoid unwanted impacts of the mining industry to the environment. Since...... to the use of cyanide to extract gold from the ore, strict control with the outfl ow of cyanide from the mine to the Kirkespir Valley is performed. The described impact on the environment of the Kirkespir Valley, both terrestrial, freshwater and marine, is considered to be minor, and is generally lower than...... the monitoring in 2010, the mining company Gold Angel Mining A/S is breaking new ore, but is also carrying previously broken ore with low grade back to the mine with vehicles with limited speed and load capacity. The gold is recovered by the use of chemical extraction (carbon-in-pulp) using cyanide. Due...

  9. Mineral chemistry and isotope geochemistry of pyrite from the Heilangou gold deposit, Jiaodong Peninsula, Eastern China

    Yutong Yan; Na Zhang; Shengrong Li; Yongsheng Li


    The Heilangou gold deposit is located in the northern QixiaePenglai gold belt, which is one amongst the three large gold belts in the eastern Shandong Province (Jiaodong Peninsula). The ore body has formed within the Guojialing granite. In this study, we report the mineral chemistry of pyrite, as well as the S, Pb, and HeO isotope data of the Heilangou gold deposit. The chemical composition of pyrite in the Heilangou gold deposit indicates that the associated gold deposit is a typical magmatic hydrothermal one. The geochemical signatures and crystal structure of pyrite show that the ore-forming materials have been derived from the crust. The S isotope data of the pyrites from Heilangou show an overall range from 5.5 to 7.8&and an average of 6.7&. The S isotope data in this deposit are similar to those from the deposits in the Jiaodong gold belt. The Pb and S isotope variations are small in the Heilangou gold deposit. The 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios are 17.4653e17.5958, 15.5105e15.5746 and 38.0749e38.4361, respec-tively. These data plot between the lower crust and the orogenic belt. The Pb isotope data in the Heilangou gold deposit are similar to those in the Linglong gold deposit. From the Qixia gold area (the Liukou and Majiayao gold deposits) to the MupingeRushan gold belt (Rushan gold deposit) to the ZhaoeYe gold belt (the Linglong, Sanshandao and Jiaojia gold deposits), the 206Pb/204Pb ratios progressively increase. The DeO isotope data obtained from quartz separates suggest that the ore-forming fluid was similar to a mixture of magmatic and meteoric waters. These results suggest that the ore-forming elements were primarily from source fluids derived from the lower crust.

  10. Tectonic setting of Late Cenozoic gold mineralization in the gold belt of Costa Rica

    Deruyter, V.D.


    The Gold Belt of Costa Rica is a northwest-elongated zone 15 km wide by 120 km long containing numerous auriferous quartz veins and pyritic silicified patterns upon which abundant small mines are developed. Gold veins are related principally to northeast-southwest and north-south striking, steeply dipping faults. Higher grade ore and thicker veins invariably occur at intersections of these fracture orientations, indicating simultaneous opening at the time of gold introduction. Restriction of gold veins to the northwest-trending arc of Miocene Aguacate Group andesite volcanic rocks, a product of Cocos Plate subduction, suggested approximately coeval formation, but recognition by the writer of the important role played by 2-5 m.y. old altered, gold mineralized rhyolite dikes intruded along north-south gold vein structures and intimately involved with high grade ores at the Esperanza Mine and Rio Chiquito prospect, for example, suggest a much younger period of fracturing and gold introduction. The rhyolite intrusions are more brittle and stockwork mineralized than andesite host rocks and form bulk tonnage gold targets. Initiation of right-lateral movement along the north-south Panama Fracture Zone at 5 m.y.a. within the pattern of northeastward Cocos Plate subduction may have tapped rhyolites from subvolcanic magma chambers into new faults.

  11. Geology and Geochemistry of Reworking Gold Deposits in Intrusive Rocks of China—Ⅱ Gold Deposits and Their Genesis

    王秀璋; 程景平; 等


    Gold deposits in intrusive masses include the veinlet dissemination,quartz vein and veinlet dissemination+vein types,They are distributed in fracture zones along the endocontact zone of a batholith or in the centre and edge of a stock.The metallogenic epochs are Yenshanian,Hercynian,Archean,Proterozoic and Himalayan,The gold deposits are characterized by a big difference in time span between gold mineralization and the formation of host masses Ore-forming materials were derived from the masses and auriferous strata and ore-forming fluids came from meteoric and formation waters.When circulating water was heated by ascending heat flow,gold would be extracted,concentrated and transported from auriferous rocks and then precipitated in the masses during the late tectonic movement,Finally gold deposits were formed in the intrusive masses.

  12. Research on Magnesite Ore Purification

    Berisha, K.


    Full Text Available Magnesite ore, consisting mainly of magnesite, MgCO3 is a chief mineral source for production of high quality refractory materials based on highly pure MgO. However, the presence of calcium and silicium mineral impurities in the ore adversely affect refractoriness. The removal of silicate minerals is now a routine process but it is not so for calcium minerals impurities. In this work, the new method for the removal of calcium mineral impurities from magnesite ore has been investigated. It is based on extraction of calcium hydroxide from the calcined hydrated ore with the solution of magnesium nitrate. The results show that it is possible to remove up to 65–83 % of calcium oxide (CaO within five minutes, and up to 88–95 % within an hour. The process itself is complex, but mainly under mass transfer control. It is possible to use waste materials produced as fertilizer in agriculture thus helping in environmental protection.

  13. Ore Petrography Using Optical Image Analysis: Application to Zaruma-Portovelo Deposit (Ecuador

    Edgar Berrezueta


    Full Text Available Optical image analysis (OIA supporting microscopic observation can be applied to improve ore mineral characterization of ore deposits, providing accurate and representative numerical support to petrographic studies, on the polished section scale. In this paper, we present an experimental application of an automated mineral quantification process on polished sections from Zaruma-Portovelo intermediate sulfidation epithermal deposit (Ecuador using multispectral and color images. Minerals under study were gold, sphalerite, chalcopyrite, galena, pyrite, pyrrhotite, bornite, hematite, chalcocite, pentlandite, covellite, tetrahedrite and native bismuth. The aim of the study was to quantify the ore minerals visible in polished section through OIA and, mainly, to show a detailed description of the methodology implemented. Automated ore identification and determination of geometric parameters predictive of geometallurgical behavior, such as grade, grain size or liberation, have been successfully performed. The results show that automated identification and quantification of ore mineral images are possible through multispectral and color image analysis. Therefore, the optical image analysis method could be a consistent automated mineralogical alternative to carry on detailed ore petrography.

  14. A Study on the Relations Between Ultrabasic Dikes and Fine Disseminated Gold Deposits in Southwestern Guizhou Province as Exemplified by Zimudang Large—Sized Gold Deposit



    The relations between ultrabasic rocks and gold deposits in time,space and genesis are discussed in this paper,the research results show that the ore-forming materials of the gold deposits is characteristic of crust-mantle mixing,The formation of the gold deposits is related with the activity of juvenile fluids along with the intrusion of ultrabasic dikes.The ascending juvenile fluids not only offered part of the gold.water and mineralizers for gold mineralization but also promoted the remobilization,deposition and enrichment of gold in crustal sediments.

  15. Virtual phosphorus ore requirement of Japanese economy.

    Matsubae, Kazuyo; Kajiyama, Jun; Hiraki, Takehito; Nagasaka, Tetsuya


    Phosphorus is indispensable for agricultural production. Hence, the consumption of imported food indirectly implies the import of phosphorus resources. The global consumption of agricultural products depends on a small number of ore-producing countries. For sustainable management of phosphorus resources, the global supply and demand network should be clarified. In this study, we propose the virtual phosphorus ore requirement as a new indicator of the direct and indirect phosphorus requirements for our society. The virtual phosphorus ore requirement indicates the direct and indirect demands for phosphorus ore transformed into agricultural products and fertilizer. In this study, the virtual phosphorus ore requirement was evaluated for the Japanese economy in 2005. Importantly, the results show that our society requires twice as much phosphorus ore as the domestic demand for fertilizer production. The phosphorus contained in "eaten" agricultural products was only 12% of virtual phosphorus ore requirement.

  16. Bioleaching of zinc from gold ores using Acidithiobacillus ferrooxidans

    Pakawadee Kaewkannetra; Francisco Jose Garcia-Garcia; Tze Yen Chiu


    that Acidithiobacillus ferrooxidans can successfully leach zinc by as much as 6 times compared with the control experiment (without Acidithiobacillus ferrooxidans ferrooxidans). The maximum efficiency (92.3%) for microbial leaching is obtained in

  17. Determination of trace gold, platinum and palladium in lean-platinum ore by bismuth fire assaying-inductively coupled plasma mass spectrometry%铋试金-电感耦合等离子体质谱法测定贫铂矿石中痕量金铂钯

    李可及; 赵朝辉; 范建雄


    为解决传统铅试金法中所存在的污染问题,通过理论计算、优化操作流程等方式建立了针对贫铂矿石中痕量金、铂、钯的铋试金-电感耦合等离子体质谱测定方法.结果表明,选用40.0g氧化铋、30.0g硼酸、20.0 g无水碳酸钠和2.0g面粉作为试金配料的组分,贵金属的选择性好,排除重金属的能力强,可基本满足贫铂矿石样品(20.0 g)中痕量金、铂、钯的测定需要.实验还针对铋扣难以完全回收的问题,采用了在出炉时趁热倾倒熔渣,使铋扣于空气中自然冷却然后取出的方法.在进行质谱测定时,选择197 Au、195 Pt、105 pd分别作为金、铂、钯的测定同位素,以185 Re、115In作为校正基体效应与信号漂移的内标元素.方法检出限(ng/g,以20.0g取样量计)分别为:0.51(Au)、0.43 (Pt)、0.50(Pd),Pt、Pd、Au测定结果的相对标准偏差(RSD,n=5)分别为4.7%、5.4%、9.7%.对GBW07291和GBW07293铂族元素地球化学标准物质中Pt、Pd、Au进行测定,测定值与认定值基本一致.方法可用于地质样品中痕量Au、Pt、Pd的准确测定.%In order to solve the pollution problem in traditional lead fire assaying method,the determination method of trace gold,platinum and palladium in lean-platinum ore by bismuth fire assaying-inductively coupled plasma mass spectrometry was established through theoretical calculation and optimization of operation procedures.The results showed that,the selectivity of precious metal by fire assaying formula containing 40.0 g of bismuth oxide,30.0 g of boric acid,20.0 g of anhydrous sodium carbonate and 2.0 g of flour was good.This formula had strong exclusion ability to precious metals and could meet the determination requirements of trace gold,platinum and palladium in lean-platinum ore samples (20.0 g).Aiming at the problem that bismuth button was hardly recovered,the melt slag was poured while hot.The bismuth button was naturally cooled in air,thus it could

  18. Fungal Biorecovery of Gold From E-waste.

    Bindschedler, Saskia; Vu Bouquet, Thi Quynh Trang; Job, Daniel; Joseph, Edith; Junier, Pilar


    Waste electric and electronic devices (e-waste) represent a source of valuable raw materials of great interest, and in the case of metals, e-waste might become a prized alternative source. Regarding gold, natural ores are difficult to mine due to their refractory nature and the richest ores have almost all been exploited. Additionally, some gold mining areas are present in geopolitically unstable regions. Finally, the gold mining industry produces toxic compounds, such as cyanides. As a result, the gold present in e-waste represents a nonnegligible resource (urban mining). Extraction methods of gold from natural ores (pyro- and hydrometallurgy) have been adapted to this particular type of matrix. However, to propose novel approaches with a lower environmental footprint, biotechnological methods using microorganisms are being developed (biometallurgy). These processes use the extensive metabolic potential of microbes (algae, bacteria, and fungi) to mobilize and immobilize gold from urban and industrial sources. In this review, we focus on the use of fungi for gold biomining. Fungi interact with gold by mobilizing it through mechanical attack as well as through biochemical leaching by the production of cyanides. Moreover, fungi are also able to release Au through the degradation of cyanide from aurocyanide complexes. Finally, fungi immobilize gold through biosorption, bioaccumulation, and biomineralization, in particular, as gold nanoparticles. Overall, the diversity of mechanisms of gold recycling using fungi combined with their filamentous lifestyle, which allows them to thrive in heterogeneous and solid environments such as e-waste, makes fungi an important bioresource to be harnessed for the biorecovery of gold. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Pb Isotope Compositions of Shibaqinghao Gold Deposit in Central Inner Mongolia, China

    ZHANG Hongying; LIANG Yibo


    There are two types of gold ore in Shibaqinghao gold deposit, a mylonite ore and a quartz - vein ore. Pb isotope compositions for mylonite ore are characterized by lower Pb isotope ratios ranging from 16.63 to 17.45 (206Pb/204Pb), 15.31 to15.48 (207Pb/204pb), 36.52 to 38.85 (208Pb/204Pb). They are scattered very close to a model curve of the mantle evolution. These ratios suggest that gold in the mylonite ore might be derived from the country rocks, which originated directly in the upper mantle. Pb isotope compositions for quartz - vein ore are characterized by higher Pb isotope ratios ranging from 18.23 to 19.74 (206Pb/204Pb), 15.69 to 15.89 (207Pb/204Pb), 38.64 to 40. 13 (208Pb/204Pb). They are scattered very close to a model curve of the upper crustal evolution. These facts indicate that the gold in the quartz - vein ore might be related to some granitic magma generated in the crust.

  20. Geochemical and GIS study of the Zarshuran Gold mine in Iran

    Sedighi, Tahereh; Sedighi, Ahmad


    Geochemical and GIS study of the Zarshuran Gold mine in Iran Sedighi Tahere 1 Sedighi Ahmad 2 (1) Geological survey of Iran ,GIS branch (2) Shabeke Pars Enginearing Company Zarshuran Gold mine is located in the north of Takab , in West of Azarbayejan Provinc There are four Gold ore types in Zarshuran ; black gouge ,Carbonate tectonized and breccia mineralized ,Massive Jasperiod and Marble and sanded. Refractory ore off Zarshuran are Gold and co-paragenetic ore like;Arsenopyrite and Orpiment. Geographic information system (GIS) has been used to determine the Gold potential of this area. By the GIS system there are different stages with contains, Gathering of all available data, Application of the integration model and the Data processing. By mineralization and Geochemical studies it is indicated that only small fraction of free Gold (21%) is present in the cyanide-soluble salpho-arsenic compound. Major Gold distribution in orpiment, regular and Arsenian Pyrite (32%) oxides, carbonates and labile sulphides (18%) and sulphides pyrite and arsenopyrite (22%). We used several information layers of the geological layer , ore deposit layer , geochemical layer , heavy mineral layer airborn Geophysical layer and remote sensing layer . Also we used from geological maps of this area. By using of the ARCGIS software , we identified the mining potentials for Gold and finally determined the Gold mining area. In this project we used the methods of simple overlay and Fuzzy logic were used. In this presentation, the authors have outlined a strategy to take up Gold mining and refractory and undersetting of the potential for refractory Gold ores in Zarshuran area ,and these results might be used for the other similar gold mines studies.

  1. Development of Technology for Enrichment of Silver Containing Ores

    Shekiladze, Asmati; Kavtelashvili, Otari; Bagnashvili, Mamuka


    The progress of Georgian economics is substantially associated with a development of new deposits of mineral resources. Among them is the David-Gareji deposit where at present the intensive searching geological works are performed. The work goal involves the elaboration of the technology for processing of silver-containing quartz-barite ores. Without its development the mining of more valuable gold-polymetallic ores is impossible. Because of ore complexity silver and barite are considered in a common technological aspect. The investigations were carried out on the representative samples of quartz-barite ores containing 78-88 g/ton of silver and 27-29 % of silver is a nugget in the form of the simple sulphides and chlorides. The ore is characterized by fine coalescence of barite and ore-generating minerals. Non-ferrous metals haven't any industrial value because of their very low content. Therefore, for the processing of the ores under study the direct selective scheme of flotation enrichment was chosen and the formula of optimal reagent regime was elaborated. Potassium xanthogenate is used as a collector for flotation of silver minerals and pine oil- as a foaming agent. The effect of the pulp - pH and medium temperature on silver flotation was studied. It was established that the silver is actively floats in neutral medium. For barite flotation the various collectors were tested: sulfidezid cotton oil-soap stock, soaps of fatty acids and alkyl sulphates of C12 - C16 row, among the “Baritol” is the most efficient one. Depression of the barren rock was carried out by liquid glass in alkaline medium. The effect of pulp pH on barite flotation has been investigated. The best results were obtained at pH=8.5. The increase of the pulp alkalinity has no essential effect on the indexes of the barite enrichment. Conditional concentrate of the barite is obtained by two fold purification of the main flotation concentrate by the addition of the liquid glass to the re

  2. Biomining-biotechnologies for extracting and recovering metals from ores and waste materials.

    Johnson, D Barrie


    The abilities of acidophilic chemolithotrophic bacteria and archaea to accelerate the oxidative dissolution of sulfide minerals have been harnessed in the development and application of a biotechnology for extracting metals from sulfidic ores and concentrates. Biomining is currently used primarily to leach copper sulfides and as an oxidative pretreatment for refractory gold ores, though it is also used to recover other base metals, such as cobalt, nickel and zinc. Recent developments have included using acidophiles to process electronic wastes, to extract metals from oxidized ores, and to selectively recover metals from process waters and waste streams. This review describes the microorganisms and mechanisms involved in commercial biomining operations, how the technology has developed over the past 50 years, and discusses the challenges and opportunities for mineral biotechnologies in the 21st century.

  3. A Study on the Ore-forming Effect of Mantle-derived Fluid

    Meng Qingqiang; Wu Jianfeng; Zhang Liuping


    Based on summarizing of the effect of mantle-derived fluid on the formation of ores, especially on gold ore,and with the latest investigations, such as the formation of ore from the action of shallow-deep fluid, the transportation effect of the thermal energy by mantle-derived fluid, this paper mainly aims at the effect of mantle-derived fluid on the generation of hydrocarbons. With the proof from geochemistry and fluid inclusion, it was suggested that the mantle-derived fluid not only supplied source materials for hydrocarbons, but also supplied essential energy and matter necessary for the generation of hydrocarbons. The mantle-derived fluid had a good effect, but at the same time it had an adverse effect under specific conditions, on the formation of reservoirs. This paper also discusses the future direction and significance of studying mantle-derived fluid.

  4. Chemical composition of the ore and occurrence state of the elements in Jingbaoshan platinum- palladium deposit

    SONG Huanbin; HE Mingqin; ZHANG Shangzhong; YI Fenghuang


    The Jingbaoshan platinum-palladium deposit is China's largest independent PGM (platinum-group metals) deposit so far discovered. There are eleven kinds of useful components in the ore: Pt, Pd, Os, Ir, Ru, Rh, Au, Ag, Cu, Ni, and Co. The platinum-group elements, gold and silver occur in the form of minerals in ores. twenty-five kinds of precious metal minerals have been found, of which twenty one belong to the platinum-group minerals. The minerals are very small in grain size. Copper occurs mainly as copper sulfide with a small amount of free copper oxide, and the beneficiated copper accounts for 95.21%. Nickel occurs mainly as nickel sulfide, and some nickel silicate and nickel oxide occur in the ore. The beneficiated nickel accounts for 72.03%. Cobalt occurs mainly as cobalt sulfide, and there are some cobalt oxide and other kinds of cobalt. The beneficiated cobalt accounts for 77.58%.

  5. Getting rid of the unwanted: highlights of developments and challenges of biobeneficiation of iron ore minerals-a review.

    Adeleke, Rasheed A


    The quest for quality mineral resources has led to the development of many technologies that can be used to refine minerals. Biohydrometallurgy is becoming an increasingly acceptable technology worldwide because it is cheap and environmentally friendly. This technology has been successfully developed for some sulphidic minerals such as gold and copper. In spite of wide acceptability of this technology, there are limitations to its applications especially in the treatment of non-sulphidic minerals such as iron ore minerals. High levels of elements such as potassium (K) and phosphorus (P) in iron ore minerals are known to reduce the quality and price of these minerals. Hydrometallurgical methods that are non-biological involving the use of chemicals are usually used to deal with this problem. However, recent advances in mining technologies favour green technologies, known as biohydrometallurgy, with minimal impact on the environment. This technology can be divided into two, namely bioleaching and biobeneficiation. This review focuses on Biobeneficiation of iron ore minerals. Biobeneficiation of iron ore is very challenging due to the low price and chemical constitution of the ore. There are substantial interests in the exploration of this technology for improving the quality of iron ore minerals. In this review, current developments in the biobeneficiation of iron ore minerals are considered, and potential solutions to challenges faced in the wider adoption of this technology are proposed.

  6. Simulation-Assisted Evaluation of Grinding Circuit Flowsheet Design Alternatives: Aghdarreh Gold Ore Processing Plant / Ocena Alternatywnych Schematów Technologicznych Procesu Rozdrabniania W Zakładach Przeróbki Rud Złota W Aghdarreh, Z Wykorzystaniem Metod Symulacji

    Farzanegan, A.; Ghalaei, A. Ebtedaei


    The run of mine ore from Aghdarreh gold mine must be comminuted to achieve the desired degree of liberation of gold particles. Currently, comminution circuits include a single-stage crushing using a jaw crusher and a single-stage grinding using a Semi-Autogenous Grinding (SAG) mill in closed circuit with a hydrocyclone package. The gold extraction is done by leaching process using cyanidation method through a series of stirred tanks. In this research, an optimization study of Aghdarreh plant grinding circuit performance was done to lower the product particle size (P80) from 70 μm to approximately 40 μm by maintaining current throughput using modeling and simulation approach. After two sampling campaigns from grinding circuit, particle size distribution data were balanced using NorBal software. The first and second data sets obtained from the two sampling campaigns were used to calibrate necessary models and validate them prior to performing simulation trials using MODSIM software. Computer simulations were performed to assess performance of two proposed new circuit flowsheets. The first proposed flowsheet consists of existing SAG mill circuit and a new proposed ball mill in closed circuit with a new second hydrocyclone package. The second proposed flowsheet consists of existing SAG mill circuit followed by a new proposed ball mill in closed circuit with the existing hydrocyclone package. In all simulations, SAGT, CYCL and MILL models were selected to simulate SAG mill, Hydrocyclone packages and ball mill units. SAGT and MILL models both are based on population balance model of grinding process. CYCL model is based on Plitt's empirical model of classification process in hydrocyclone units. It was shown that P80 can be reduced to about 40 μm and 42 μm for the first and second proposed circuits, respectively. Based on capital and operational costs, it can be concluded that the second proposed circuit is a more suitable option for plant grinding flowsheet

  7. Ore—Search Perspective for Superlarge Gold Deposits in the Jiaolai Basin of the Jiaodong Gold Metallogenetic Domain

    张竹如; 陈世桢; 等


    There are three types of gold deposits in the Jiaodong gold metallogenetic domain.The strata-bound gold deposits are a new type,which occur in a hydrocarbon-dled double-source bed enriched in gold(Au 174ng/g) and organic carbon(0.007-4.225%),At diagenetic a d hydrotherrmal stages water and oil were simultaneously activated and the stratabound gold deposits were formed from interactions between water ,oil and rocks.In the late Yanshanian period,gold oreboides were enriched and enlarged in response to tectonmoagmatism and action of complex ore-forming hydrothermal solutions.As a results,it is highly expected to find suparlarge gold deposits and the Yanzi area is expected to be a perspective target area.

  8. Measurement of moisture in mill feed ore

    Timm, A.R.; Moench, P.; Moisel, E. (Council for Mineral Technology, Randburg (South Africa))


    The control of the moisture in the feed to a mill is very important for efficient mill operation. Water is added continuously to the ore fed to a mill to maintain a suitable mix of ore and moisture in the mill. However, problems arise because of the large variation in the moisture content of the ore, which affects the efficiency of the grind. If too little moisture is present, the mill is unable to grind the ore finely enough, creating instead a thick 'porridge' that causes the mill to choke up. On the other hand, too much moisture results in inefficient grinding because the ore is flushed through the mill too quickly. Several techniques are available for measuring moisture and Mintek undertook an investigation in an attempt to develop a reliable robust moisture meter suitable for monitoring the moisture content of ore, which include the following: neutron backscattering, infrared absorption, microwaves, capacitance and moisture as a function of conductivity.

  9. Gold resource modeling using pod indicator kriging

    Bargawa, Waterman Sulistyana; Rauf, Abdul; Amri, Nur Ali


    This paper describes an implementation of the pod indicator kriging method used to gold resource modeling. Method such as ordinary kriging estimate the mean grade of a block that is fairly large. The usual outcome is that large blocks rarely turn out to be all ore or all waste, thus making reserve estimates an incorrect estimate of what will be mined. Pod indicator kriging offers a solution to this problem by estimating the distribution of grade values within a large block, rather than just estimating the mean grade of the block. Knowing the distribution of grade value within the block, it is then easy to calculate the proportion of the block that is above cutoff grade and the grade of the ore above cutoff grade. This research shows that the pod indicator kriging model is quite applicable and reliable in gold resourcemodeling.

  10. Geology of the florencia gold – telluride deposit (camagüey, cuba) and some metallurgical considerations

    López K Jesús M.; Moreira Jesús; Gandarillas José


    This paper describes the results from a study of the Florencia gold-telluride deposit in Central Cuba, including mineralogical, petrographical, microprobe and chemical analysis. Valuable information is provided for the exploration, mining and processing of gold ores from other nearby deposits with similar characteristics. Results highlight changes in the mineralogical composition of the ores between the north and south sectors of the deposit, as reflected in metallurgical concentrates after b...

  11. Study on Mineralization Age of Xiaoban Gold Deposit, Fujian Province


    The Xiaoban gold deposit is a large-size deposit recently found in middle area of Fujian Province. It belongs to magmatic hydrothermal type occurred in Mayuan Group metamorphic rocks of Middle Proterozoic and is controlled by low angle fault (detachment) structures. The contents of Au in Mayuan Group metamorphic rocks, Caledonian-Indosinian deformed granite and early Yanshanian granite are higher with Au enrichment coefficient of 2.06-5.68, 5.11 and 6.67 than those in other geological bodies. And the higher enrichment coefficients (>2) of Ag, S, Sn and Te are similar to those of gold ore. Meanwhile, the distribution of Au in Mayuan Group metamorphic rocks and early Yanshanian granite with a low D-value (0.58 and 0.67) is favorable to gold mineralization. REE characteristics of gold ore, ratios of (LREE/HREE), (La/Sm)n, (Yb/Lu)n, (La/Tb)n and (Sm/Nd)n are similar to Mayuan Group metamorphic rocks, only non or little normal Eu abnormal of ore is dissimilar to metamorphic rocks. The δ(34S) of the gold ore, with a high homogenization, is (-4.7×10-3)-(-2.7×10-3). The study of inclusion indicates 180-249 ℃ of mineralization temperature, 3.69 %-11.81 % of salinities and 0.869-0.991 g/cm3 of densities of mineralization fluid. Based on hydrogen and oxygen isotope (δ(18O)=11.0×10-3-11.7×10-3, δ(D)=(-48×10-3)-(-62×10-3)) and initial w(87Sr)/w(86Sr) =0.715,combining to the analysis of geological history, regional metamorphism and magamtic activity, the authors confirm that the source for the ore fluid was mainly from magmatic, partly from metamorphic water, and with a little influence of meteoric water. Isotopic dating made on Rb-Sr isochron age of 182 Ma, by using alteration minerals of gold-ores from the deposit, indicates that the mineralization occurs in early Yanshanian epoch. This is close to the age of 187 Ma of the Anchun magmatite with a similar alteration and gold mineralization to the Xiaoban gold deposit. The age of early Yanshanian epoch of the Xiaoban

  12. Geochemistry of Main Types of Gold Deposits in Shear Zones,China

    吴学益; 杨元根; 等


    Shear zone-hosted gold deposits in China can be divided into four types:ductile,brittle-ductile,ductile-brittle and brittle,of which the ductile and brittle types are the basic ones.All these types of gold deposits have their own geochemical characteristics.The Hetai gold deposit in Guangdong Province,for example,is a mylonite-type gold deposit in a ductile shear zone.With increasing mylonitization,obvious changes took place in trace elements in minerals and rocks,enriching gold and mineralizing elements.The S and Pb isotope data indicated that the ore-forming materials were derived from the strata.Hydrogen and oxygen isotopic and fluid inclusion studies also implied that the ore-forming fluid was much closer to meteoric water from the early to the late ore-forming stage.The Linglong gold deposit,Shangdong Province,is a quartz-type gold deposit in a brittle shear zone.Changes in rocks,minerals and trace elements occurred in the process of f ormation of gold quartz veins,and the analytical results of S,Pb ,Hand O isotopes showed that ore deposition is connected not only with the Jiaodong Group,but also with anatexic granites.

  13. Metallogenic Features and Metalogenic Model of Laterite Gold Deposits in Southern China


    The modern laterite gold deposits in southern China, which belong to reworked laterite deposits, can be further divided into three subclasses and seven types. Their geological features, ore-forming conditions and regularities are discussed. A geologic-geochemical metallogenic model for laterite gold deposits has been established.

  14. World-class Xincheng gold deposit:An example from the giant Jiaodong gold province

    Liqiang Yang; Jun Deng; Ruipeng Guo; Lin’nan Guo; Zhongliang Wang; Binghan Chen; Xudong Wang


    The Jiaodong gold deposits are currently the most important gold resources (with Au reserves of>4000 t) in China, and the leading gold-producing country globally (with Au production of w428 t in 2013). Jiaodong is also considered as perhaps the only world-class to giant gold accumulation on the planet where relatively young gold ores (ca. 130e120 Ma) were deposited in rocks that are 2 Ga older. The Xincheng world-class high-grade gold deposit, with a proven reserve of >200 t gold, is one of the largest deposits in the giant gold province of the Jiaodong Peninsula. It is located in the northwestern part of the Jiaobei Uplift, and hosted by ca. 132e123 Ma Xincheng quartz monzonites and monzogranites. Ore zones are structurally controlled by the NE-trending and NW-dipping Jiaojia Fault and subsidiary faults, and are mainly restricted to the footwall of the fault. The dominant disseminated-and stockwork-style ores are associated with strong sericitization, silicification, sulfidation and K-feldspathization, and minor carbonate wallrock alteration halos. The four mineralization stages are pyriteequartzesericite (stage 1), quartzepyrite (stage 2), quartzepolysulfide (stage 3) and quartzecarbonate (stage 4). Gold occurs dominantly as electrum, with lesser amounts of sulfide-hosted native gold and rare native silver and argentite, normally associated with pyrite, chalcopyrite, galena and sphalerite:the latter with proven resources of about 105 t Ag, 713 t Cu, and 5100 t S. There are three types of ore-related fluid inclusions: type 1 aqueous-carbonate (H2OeCO2), type 2 aqueous (liquid H2O þ vapor H2O), and type 3 CO2 (liquid CO2 and vapor CO2) inclusions. Homogeni-zation temperatures range from 221 to 304 ?C for type 1 inclusions, with salinities of 2.4e13.3 wt.%NaCl eq., and bulk densities of 0.858e1.022 g/cm3. The d34SCDT values of hydrothermal sulfides are 4.3e10.6&and d18O values of hydrothermal quartz have a median value of 13.0&. dD values of fluid inclusions in

  15. Hageri alustas oreli taastamisega / Inge Põlma

    Põlma, Inge


    1851. aastal eesti orelimeistri Carl Tantoni valmistatud ja 1892. aastal Gustav Terkmanni poolt kohendatud Hageri Lambertuse kiriku oreli restaureerimisest, ekspertiisi tegi rootsi organist Göran Grahn

  16. Geology and Genesis of the Superlarge Jinchang Gold Deposit, NE China

    JIA Guozhi; CHEN Jinrong; YANG Zhaoguang; BIAN Hongye; WANG Yangzhong; LIANG Haijun; JIN Tonghe; LI Zhenhui


    The superlarge Jinchang gold deposit is located in the joint area between the Taipinglinguplift and the Laoheishan depression of the Xingkai Block in both eastern Jilin and easternHeilongjiang Province. Wall rocks of the gold deposits are the Neoproterozoic Huangsong Group ofmetamorphic rocks. Yanshanian magmatism in this region can be divided into 5 phases, the diorite,the graphic granite, the granite, the granite porphyry and the diorite porphyrite, which resulted in themagmatic domes and cryptoexplosive breecia chimney followed by large-scale hydrothermalalteration. Gold mineralization is closely related to the fourth and fifth phase of magmatism.According to the occurrences, gold ores can be subdivided into auriferous pyritized quartz vein,auriferous quartz-pyrite vein, auriferous polymetallic sulfide quartz vein and auriferous pyritizedcalcite vein. The ages of the gold deposit are ranging from 122.53 to 119.40 Ma. The ore bodies werecontrolled by a uniform tectono-magmatic hydrothermal alteration system that the ore-formingmaterials were deep derived from and the ore-forming fluids were dominated by magmatic waterswith addition of some atmospheric water in the later phase of mineralization. Gold mineralizationtook place in an environment of medium to high temperatures and medium pressures. Ore-formingfluids were the K+-Na+-Ca2+-Cl--SO42- type and characterized by medium salinity or a slightly higher,weak alkaline and weak reductive. Au in the ore-forming fluids was transported as complexes of [Au(HS)2]-, [AuCl2]-, [Au(CO2)]- and [Au(HCO3)2]-. Along with the decline of temperatures andpressures, the ore-forming fluids varied from acidic to weak acidic and then to weak alkaline, whichresulted in the dissociation of the complex and finally the precipitation of the gold.

  17. Gold recycling and enrichment beneath volcanoes: A case study of Tolbachik, Kamchatka

    Zelenski, Michael; Kamenetsky, Vadim S.; Hedenquist, Jeffrey


    Magmas supply metals to hydrothermal ore deposits, although typical arc basalts may be unable to produce a gold-rich ore-forming fluid, as such basalts rarely exceed 5 ppb Au. Consistent with this, the occurrence of native gold of magmatic origin is extremely rare, and only a few finds of micron-sized gold particles in unaltered basalts have been documented. Surprisingly, some lava flows and scoria cones of the historic basaltic eruptions of Tolbachik volcano (Kamchatka) are unusually gold-rich. Tolbachik basalts contain up to 11.6 ppb Au based on whole rock analyses, nuggets of gold (electrum) up to 900 μm in size and native gold droplets up to 200 μm, plus numerous vapor-deposited gold crystals within fumarolic incrustations and directly on surfaces of basaltic lapilli. Our results demonstrate that the gold nuggets in Tolbachik basalt are of hydrothermal origin and were physically scavenged from epithermal veins hosted by country rocks during intrusion of mafic magmas. Depending on the melt temperature and/or time span of the melt-rock interaction, gold was ejected by the erupting volcano either in the form of abraded nuggets or liquid droplets, or was fully assimilated (dissolved) into the shallow long-lived magma chamber to provide a 4-fold increase in gold content over background concentration of 2.7 ppb Au, characteristic of mafic volcanic rocks in Kamchatka. Upon the end of the eruption, the continued discharge of volcanic vapors enriched in gold deposited abundant crystals of gold on cooling lava and scoria. Similar to Tolbachik, recycling of metals from prior accumulations (ore deposits) in the shallow crust may take place in other long-lived magma reservoirs, thus upgrading the gold and other metal contents and contributing to the ore-forming potential of a magma.


    López K Jesús M.


    Full Text Available This paper describes the results from a study of the Florencia gold-telluride deposit in Central Cuba, including mineralogical, petrographical, microprobe and chemical analysis. Valuable information is provided for the exploration, mining and processing of gold ores from other nearby deposits with similar characteristics. Results highlight changes in the mineralogical composition of the ores between the north and south sectors of the deposit, as reflected in metallurgical concentrates after beneficiation and flotation of samples from these sectors.
    It is shown that gold deposits of the Cretaceous Volcanic Arc of Cuba largely consist of native gold, telluride and pyrite, where arsenopyrite is almost absent. Traces of lead, zinc and cadmium are present in the periphery of the main ore zones.

  19. The dilemma of the Jiaodong gold deposits: Are they unique?

    Richard J. Goldfarb


    Classification of the gold deposits remains problematic. Many features resemble those typical of orogenic Au including the linear structural distribution of the deposits, mineralization style, ore and alteration assemblages, and ore fluid chemistry. However, Phanerozoic orogenic Au deposits are formed by prograde metamorphism of accreted oceanic rocks in Cordilleran-style orogens. The Jiaodong deposits, in contrast, formed within two Precambrian blocks approximately 2 billion years after devolatilization of the country rocks, and thus require a model that involves alternative fluid and metal sources for the ores. A widespread suite of ca. 130–123 Ma granodiorites overlaps temporally with the ores, but shows a poor spatial association with the deposits. Furthermore, the deposit distribution and mineralization style is atypical of ores formed from nearby magmas. The ore concentration requires fluid focusing during some type of sub-crustal thermal event, which could be broadly related to a combination of coeval lithospheric thinning, asthenospheric upwelling, paleo-Pacific plate subduction, and seismicity along the continental-scale Tan-Lu fault. Possible ore genesis scenarios include those where ore fluids were produced directly by the metamorphism of oceanic lithosphere and overlying sediment on the subducting paleo-Pacific slab, or by devolatilization of an enriched mantle wedge above the slab. Both the sulfur and gold could be sourced from either the oceanic sediments or the serpentinized mantle. A better understanding of the architecture of the paleo-Pacific slab during Early Cretaceous below the eastern margin of China is essential to determination of the validity of possible models.

  20. Iron from Zealandic bog iron ore -

    Lyngstrøm, Henriette Syrach


    og geologiske materiale, metallurgiske analyser og eksperimentel arkæologiske forsøg - konturerne af en jernproduktion med udgangspunkt i den sjællandske myremalm. The frequent application by archaeologists of Werner Christensen’s distribution map for the occurrence of bog iron ore in Denmark (1966...... are sketched of iron production based on bog iron ore from Zealand....

  1. The Luster of Iron Ore Prices


    China battles its way out of an iron ore stalemate by finding alternative supplier After months of seesawing, China’s iron ore negotiators appear to be breaking through the tight encirclement of suppliers. On August 17, the China Iron and Steel Association (CISA) announced that Fortescue

  2. Structural controls on Carlin-type gold mineralization in the gold bar district, Eureka County, Nevada

    Yigit, O.; Nelson, E.P.; Hitzman, M.W.; Hofstra, A.H.


    The Gold Bar district in the southern Roberts Mountains, 48 km northwest of Eureka, Nevada, contains one main deposit (Gold Bar), five satellite deposits, and other resources. Approximately 0.5 Moz of gold have been recovered from a resource of 1,639,000 oz of gold in Carlin-type gold deposits in lower plate, miogeoclinal carbonate rocks below the Roberts Mountains thrust. Host rocks are unit 2 of the Upper Member of the Devonian Denay Formation and the Bartine Member of the McColley Canyon Formation. Spatial and temporal relations between structures and gold mineralization indicate that both pre-Tertiary and Tertiary structures were important controls on gold mineralization. Gold mineralization occurs primarily along high-angle Tertiary normal faults, some of which are reactivated reverse faults of Paleozoic or Mesozoic age. Most deposits are localized at the intersection of northwest- and northeast-striking faults. Alteration includes decalcification, and to a lesser extent, silicification along high-angle faults. Jasperoid (pervasive silicification), which formed along most faults and in some strata-bound zones, accounts for a small portion of the ore in every deposit. In the Gold Canyon deposit, a high-grade jasperoid pipe formed along a Tertiary normal fault which was localized along a zone of overturned fault-propagation folds and thrust faults of Paleozoic or Mesozoic age.

  3. Tellurium-Gold Mineralization Related to Cryptoexplosive Breccias within Volcanic Pipe in Zhuojiazhuang Gold Deposit,Shandong Province, China

    Zeng Qingdong; Liu Tiebing; Shen Yuanchao; Li Guangming


    Zhuojiazhuang gold deposit (ZGD) is the most enriched breccia pipe type gold deposit in East China, resulted from cryptoexplosion related to alkalinic magmatism and orebearing fluid filling. The ZGD is a small-sized mine with over 5 tons of gold reserves and grade of 156g/t in average and the highest 2 728 g/t as known. In addition, tellurium and silver are also valuable.The mineralized breccia pipe is cylinder-like in shape with 15 m long and 10 m wide and controlled by intersection ofNW and EW trend faults. Mining level has reached 170 m below the surface, but the whole pipe mineralization is still stable. Mineralization commonly occurs within the cements of breccias. Gold ores consist of hydrothermal breccia ore, shatteredbreccia ore and cataclastic ore. From the center of the ore body outwards, there is the transition from hydrothermal breccia toshattered breccia and then to cataclastic ores. According to composition and amount of the cements, the hydrothermal brecciaores can further be divided into three subtypes: sulfides cemented, hydrothermal mineral cemented and magma cemented.The content of gold is closely related to the types of the cements. The grade of the sulfide cemented breccia is the highestone, usually more than 1 000 g/t, and the known maximum grade is 2 728 g/t. The composition of the shattered breccia ismainly dioritic porphyrite and cemented by hydrothermal minerals, the grade ranges from ten to several tens g/t. The catsclastic ores are mainly composed of dioritic porphyrite, syenitic porphyry, as well as carbonate with mineralized veins, and the grade is only 35 g/t.Major ore minerals consist of pyrite, native tellurium, sphalerite, with minor calaverite, galena and altaite. Gangueminerals are composed of microcrystalline quartz, decktite and fluorite, with minor sericite and calcite. Brecciated and disseminited structures are main structures of ores. Four ore-forming stages are defined: microcrystalline quartz-pyrite stage

  4. Biomass for iron ore sintering

    Zandi, M.; Martinez-Pacheco, M.; Fray, T.A.T. [Corus Research Development & Technology, Rotherham (United Kingdom)


    Within an integrated steelworks, iron ore sinter making is an energy intensive process. In recent years, biomass is becoming an attractive alternative source of energy to traditional fossil fuels such as coal. In this study, commercially available biomass materials suited to sinter making have been identified as an alternative source of fuel to coke breeze. Olive residues, sunflower husk pellets, almond shells, hazelnut shells and Bagasse pellets have been characterised and prepared for sintering. A laboratory sinter pot has been employed for studying sintering behaviour of biomass material. On average, the calorific values of selected biomass materials, on a dry basis, are about 65% of dry coke breeze. It was found that less of this energy would be available in sinter making due to the evaporation of some of the volatile matter ahead of the flame front. At a replacement rate of 25%, the crushed sunflower husk pellets showed the closest thermal profile to that of coke breeze alone in the size range of -0.8 to +0.6 mm. A specification of less than 1 mm has been recommended for the studied biomass materials when co-firing biomass with coke breeze for iron ore sintering.

  5. Crust-Mantle Structures and Gold Enrichment Mechanism of Mantle Fluid System

    邓军; 孙忠实; 王庆飞; 韦延光


    Gold enrichment mechanism of ore-forming fluid is the essence of gold metallization.This paper summarizes the distinguishing symbols of mantle fluid and effect of crust-mantlestructure on fluid movement. Fluid moving processes include osmosis, surge, gas-liquid alterna-tion and mutation of fluid speed. During fluid movement, gold will be enriched gradually. Final-ly, a layered circulatory system is illustrated in this paper.

  6. Geological and Geochemical Characteristics of the Zhulazhaga Gold Deposit in Inner Mongolia,China

    JIANG Sihong; NIE Fengjun


    Located in Alxa Zuoqi (Left Banner) of Inner Mongolia, China, the Zhulazhaga gold deposit is the first largescale gold deposit that was found in the middle-upper Proterozoic strata along the north margin of the North China craton in recent years. It was discovered by the No. 1 Geophysical and Geochemical Exploration Party of Inner Mongolia as a result of prospecting a geochemical anomaly. By now, over 50 tonnes of gold has been defined, with an average Au grade of 4 g/t. The ore bodies occur in the first lithological unit of the Mesoproterozoic Zhulazhagamaodao Formation (MZF), which is composed mainly of epimetamorphic sandstone and siltstone and partly of volcanic rocks. With high concentration of gold,the first lithological unit of the MZF became the source bed for the late-stage ore formation. Controlled by the interstratal fracture zones, the ore bodies mostly appear along the bedding with occurrence similar to that of the strata. The primitive ore types are predominantly the altered rock type with minor ore belonging to the quartz veins type. There are also some oxidized ore near the surface. The metallic minerals are composed mainly of pyrite, pyrrhotite and arsenopyrite with minor chalcopyrite, galena and limonite. Most gold minerals appear as native gold and electrum. Hydrothermal alterations associated with the ore formation are actinolitization, silicatization, sulfidation and carbonation.A total of 100 two-phase H20-rich and 7 three-phase daughter crystal-bearing inclusions were measured in seven goldbearing quartz samples from the Zhulazhaga gold deposit. The homogenization temperatures of the two-phase H2O-rich inclusions range from 155 to 401℃, with an average temperature of 284℃ and bimodal distributions from 240 to 260℃ and 300 to 320℃ respectively. The salinities of the two-phase H20-rich inclusions vary from 9.22wt% to 24.30wt% NaCl equiv, with a mode between 23 wt% and 24wt% NaCl equiv. Comparatively, the homogenization temperatures of

  7. Application of natural analog studies to exploration for ore deposits

    Gustafson, D.L. [Consulting Economic Geologist, Reno, NV (United States)


    Natural analogs are viewed as similarities in nature and are routinely utilized by exploration geologists in their search for economic mineral deposits. Ore deposit modeling is undertaken by geologists to direct their exploration activities toward favorable geologic environments and, therefore, successful programs. Two types of modeling are presented: (i) empirical model development based on the study of known ore deposit characteristics, and (ii) concept model development based on theoretical considerations and field observations that suggest a new deposit type, not known to exist in nature, may exist and justifies an exploration program. Key elements that are important in empirical model development are described, and examples of successful applications of these natural analogs to exploration are presented. A classical example of successful concept model development, the discovery of the McLaughlin gold mine in California, is presented. The utilization of natural analogs is an important facet of mineral exploration. Natural analogs guide explorationists in their search for new discoveries, increase the probability of success, and may decrease overall exploration expenditure.

  8. A New Genetic Type of Gold Deposits-Meso-Epithermal Carbonate-Type Gold Deposits as Exemplified by the Baguamiao Suprlarge Gold Deposit


    Gold deposits of the meso-epithermal carbonate type were first proposed based on the study of the Baguamiao gold deposit.This new type of gold deposits has many unique characteristics as follows:(1)Obviously strata-bound.The gold deposits are hosted in Middle Devonian turbidite formations;(2)Structrually controlled.Struc-ture is an important factor leading to metallogenesis of this type of gold deposits.The shape and distribution of orebodies are controlled by byittle-ductile shear zones;(3)Multi-stage wall-rock alteration.According to the characteristics of mineral assemblage,gold mineralization can be classified into three stages in association with various wall-rock al-terations.Wall-rock alterations closely genetically related to the gold mineralization are ankerization ,silicification,pyrrhotization and pyritization ;(4)Mineral compositions of the orebodies are mainly pyrrhotite,pyrite,marcasitolite,chalcopyrite,quartz,ankerite,and sericite.Gold mineralization is associated closely in space and time with iron sulfides;(5)Rare elements and REE in ores are low in contents relative to those of the crust.Au content varies from 1.91g/t to 11.15g/t ,averaging 5.5g/t;(6)Studies of sulfur,hydrogen,oxygen and carbon isotopes in main gangue minerals (quartz and ankerite)indicate that fluids and ore-forming materials came from deep-seated sources;(7)Three types of inclusions are recognized in terms of their composition and the vapor amounts of inclusions.The homogenization temperatures of inclusions range from 210℃to 310℃,averaging 230℃,showing that this type of gold deposits belongs to the meso-epithermal type;(8)Metallogenic age of this type of gold deposits is similar to that of the collision between the Yangtze Plate and the North China Plate,indicating that gold deposits of this type are genetically related to continental-margin plate activity.

  9. The characteristics, origins, and geodynamic settings of supergiant gold metallogenic provinces

    Robert; Kerrich[1; Richard; Goldfarb[2; David; Groves[3; Steven; Garwin[4


    There are six distinct classes of gold deposits, each represented by metallogenic provinces, having 100’s to > 1 000 tonne gold production. The deposit classes are: (1) erogenic gold; (2) Carlin and Carlin-like gold deposits; (3) epithermal gold-silver deposits; (4) copper-gold porphyry deposits; (5) iron-oxide copper-gold deposits; and (6) gold-rich volcanic hosted massive sul-fide (VMS) to sedimentary exhalative (SEDEX) deposits. This classification is based on ore and alteration mineral assemblages; ore and alteration metal budgets; ore fluid pressure(s) and compositions; crustal depth or depth ranges of formation; relationship to structures and/or magmatic intrusions at a variety of scales; and relationship to the P-T-t evolution of the host terrane. These classes reflect distinct geodynamic settings. Orogenic gold deposits are generated at mid-crustal (4-16 km) levels proximal to terrane boundaries, in transpressional subduction-accretion complexes of Cordilleran style erogenic belts; other orogeni

  10. Physical Properties of the Triassic Host Strata and Their Relations With Gold Mineralization in Youjiang Rift,South China

    张景荣; 陆建军; 等


    Micro-fine disseminated gold deposits are hosted in the Triassic Baipeng Formation (argillaceous siltstone and arenaceous mudstone)in the Youjiang Rift,South China.Physical properties(grain size,specific surface,porosity and permeability)of the host rocks are studied with respect to ore-fluid cirulation,water-rock reaction and the effective volume from which ore-components could be extracted.On this basis,it is considered that the ore-fluid and oremetals were extracted mainly from the strata and hydrothermal solutions,tending to move to wards low-energy sites,depositing their gold in fault zones at the margins of the basin and in the circle fracture systems around underwater uplifts.The gold deposits resulted from the deepcirculation of hydrothermal solutions,Probably aided by multi-stage superimposition The quantites of ore-fluid necessary to form the deposits were estimated.

  11. Advances in research of sulphide ore textures and their implications for ore genesis

    GU Lianxing; ZHENG Yuanchuan; TANG Xiaoqian; WU Changzhi; HU Wenxuan


    Important advances in research of sulphide ore textures in recent years have deepened our understanding of ore genesis of related mineral deposits. Pressure solution of sulphide minerals has been suggested as a mechanism for remobilization of ore materials,whereas pressure solution of the gangues is believed to raise the grade of the primary ores. We have known that precipitation of base metal sulphides from fluids prefers crystal and crack surfaces of pyrite to form overgrowth. Therefore, pyrite-bearing embryo beds in a sedimentary sequence can be acted as effective crystal seed beds and are favorable for fluid overprinting to form huge statabound deposits. Texture studies of various sulphides can be used to interpret the entire history of sedimentation, diagenesis, deformation and metamorphism of the ores. The study of chalcopyrite disease in sphalerite has brought about the idea of zone refining, and given a new explanation to metal zonation in massive sulphide deposits. Ductile shearing of sulphide ores may form ore mylonites, which will become oreshoots enriched in Cu, Au and Ag during late-stage fluid overprinting. Despite that various modern analytical techniques are being rapidly developed, ore microscopy remains to be an unreplaceable tool for ore geologists. Combined with these modern techniques, this tool will help accelerate the development of theories on ore genesis.

  12. Nitrile O-ring Cracking: A Case of Vacuum Flange O-ring Failures

    Dees, Craig


    A review of recent nitrile O-ring failures in ISO-KF vacuum flange connections in glovebox applications is presented. An investigation of a single “isolated” o-ring failure leads to the discovery of cracked nitrile o-rings in a glovebox atmospheric control unit. The initial cause of the o-ring failure is attributed to ozone degradation. However, additional investigation reveals nitrile o-ring cracking on multiple gloveboxes and general purpose piping, roughly 85% of the nitrile o-rings removed for inspection show evidence of visible cracking after being in service for 18 months or less. The results of material testing and ambient air testing is presented, elevated ozone levels are not found. The contributing factors of o-ring failure, including nitrile air sensitivity, inadequate storage practices, and poor installation techniques, are discussed. A discussion of nitrile o-ring material properties, the benefits and limitations, and alternate materials are discussed. Considerations for o-ring material selection, purchasing, storage, and installation are presented in the context of lessons learned from the nitrile o-ring cracking investigation. This paper can be presented in 20 minutes and does not require special accommodations or special audio visual devices.

  13. Gold deposits of the Carolina Slate Belt, southeastern United States--Age and origin of the major gold producers

    Foley, Nora K.; Ayuso, Robert A.


    Gold- and iron sulfide-bearing deposits of the southeastern United States have distinctive mineralogical and geochemical features that provide a basis for constructing models of ore genesis for exploration and assessment of gold resources. The largest (historic) deposits, in approximate million ounces of gold (Moz Au), include those in the Haile (~ 4.2 Moz Au), Ridgeway (~1.5 Moz Au), Brewer (~0.25 Moz Au), and Barite Hill (0.6 Moz Au) mines. Host rocks are Late Proterozoic to early Paleozoic (~553 million years old) metaigneous and metasedimentary rocks of the Carolina Slate Belt that share a geologic affinity with the classic Avalonian tectonic zone. The inferred syngenetic and epithermal-subvolcanic quartz-porphyry settings occur stratigraphically between sequences of metavolcanic rocks of the Persimmon Fork and Uwharrie Formations and overlying volcanic and epiclastic rocks of the Tillery and Richtex Formations (and regional equivalents). The Carolina Slate Belt is highly prospective for many types of gold ore hosted within quartz-sericite-pyrite altered volcanic rocks, juvenile metasedimentary rocks, and in associated shear zones. For example, sheared and deformed auriferous volcanogenic massive sulfide deposits at Barite Hill, South Carolina, and in the Gold Hill trend, North Carolina, are hosted primarily by laminated mudstone and felsic volcanic to volcaniclastic rocks. The high-sulfidation epithermal style of gold mineralization at Brewer and low-sulfidation gold ores of the Champion pit at Haile occur in breccias associated with subvolcanic quartz porphyry and within crystal-rich tuffs, ash flows, and subvolcanic rhyolite. The Ridgeway and Haile deposits are primarily epithermal replacements and feeder zones within (now) metamorphosed crystal-rich tuffs, volcaniclastic sediments, and siltstones originally deposited in a marine volcanic-arc basinal setting. Recent discoveries in the region include (1) extensions of known deposits, such as at Haile where

  14. Oolitic ores in the Bakchar iron-ore cluster (Tomsk Oblast)

    Rudmin, M. A.; Mazurov, A. K.


    Oolitic iron ores are typified, and their morphology and composition are studied. Special attention is focused on the character of distribution of valuable and harmful admixtures and determination of the principal minerals concentrating these elements. As a result of this study, three types of ores are identified, such as "loose" ores, cemented ores with glauconite-chlorite-clay cement, and well-cemented ores with siderite cement. The morphology and composition of the ore oolites are characterized. The forms of occurrence of calcium phosphates (anapaite) and phosphates of rare-earth elements (monazite, cularite) that are related to the harmful phosphorus admixture are described. According to the analysis of the elemental composition, the fractions of (-1…+0.2) and (-1…+0.1) mm in the western and eastern segments, respectively, may be promising for processing.

  15. Geological and technological evaluation of gold-bearing mineral material after photo-electrochemical activation leaching

    Manzyrev, DV


    The paper reports the lab test results on simulation of heap leaching of unoxidized rebellious ore extracted from deep levels of Pogromnoe open pit mine, with different flowsheets and photo-electrochemically activated solutions. It has been found that pre-treatment of rebellious ore particles –10 mm in size by photo-electrochemically activated solutions at the stage preceding agglomeration with the use of rich cyanide solutions enhances gold recovery by 6%.

  16. Geological Characteristics of Epithermal Ore Concentrated Areas and Epithermal Ore Deposits in China


    The epithermal ore concentrated area is located in Southwestern China. We systematically study the regional geological characteristics such as the basement of Proterozoic, the capping bed, Moho, geothermal feature and tectonics, and discuss the relationship between distributed characteristics of the epithermal ore deposits and ore-control factors in this paper. It is concluded that the conditions, under which the epithermal ore deposits form, are huge thick basement of Proterozoic, long-time and wide-scope developed capping bed and weak magmatic activity. The basement of Proterozoic that enriches volcanic matters and carbon and the carbonaceous-bearing and paleo-pool-bearing capping bed provides main ore source. The large and deep faults and paleopool accordance with gravity anomaly gradient control the distribution of epithermal ore deposits. The lithologic assembles of microclastic rocks and carbonate rocks in the capping bed provide spaces of ore precipitation and create conditions of ore precipitation. The coincidence of many geological factors above forms the epithermal ore concentrated area.

  17. Geochemical Study of Gold and Arsenic Mineralization of the Carlin-Type Gold Deposits, Qinling Region, China

    张复新; 马建秦; 陈衍景


    Element geochemistry of gold and arsenic and mineralogical features of their sulfides in the Carlin-type gold deposits of the Qinling region are discussed in this paper. The initial contents of ore-forming elements such as gold and arsenic are high in the ore-bearing rock series in the Qinling region. Furthermore, both the metals are concentrated mainly in the diagenetic pyrite. Study on the mineralogy of arsenic-bearing sulfide minerals in the ores demonstrated that there is a positive correlation between gold and arsenic in the sulfide minerals. Available evidence suggests that gold in the As-bearing sulfide minerals is likely to be presented as a charge species (Au + ), and it is most possible for it to replace the excess arsenic at the site of iron and was probably deposited together with arsenic as solid solution in the sulfide minerals.Pyrite is composed of (Au3x+, Fe12-+ x) ([AsS]3x- [S2]12--x), and arsenopyrite of (Au3x+ , Fe13-+x)([AsS]3x- [AsS2 ]1-3-x). The occurrence of gold in the As-sulfide minerals from the Carlin-type gold deposits in the Qinling region has been confirmed by electron probe and transmission elec tron microscopic studies. The results show that gold was probably deposited together with ar senic as coupled solid solutions in sulfide minerals in the early stage of mineralization. Metallo genic chemical reactions concerning gold deposition in the Carlin-type As-rich gold deposits would involve oxidation of gold and concurrent reduction of arsenic. Later, the deposited gold as solid solution was remobilized and redistributed as exsolutions, as a result of increasing hy drothermal alteration and crystallization, and decreasing resistance to refractoriness of the host minerals. Gold occurs as sub-microscopic grains (ranging from 0.04 to 0.16 μm in diameter)of native gold along micro factures in and crystalline grains of the sulfides.

  18. The sources of our iron ores. II

    Burchard, E.F.


    In this instalment** the iron ore deposits of the Lake Superior States, which normally furnish about 80 per cent, of the annual output of the United States, are described together with historical notes on discovery and transportation of ore. Deposits in the Mississippi Valley and Western States are likewise outlined and the sources of imported ore are given. Reviewing the whole field, it is indicated that the great producing deposits of the Lake Superior and southern Appalachian regions are of hematite in basin areas of sedimentary rocks, that hydrated iron oxides and iron carbonates are generally found in undisturbed comparatively recent sediments, and that magnetite occurs in metamorphic and igneous rocks; also that numerical abundance of deposits is not a criterion as to their real importance as a source of supply. Statistics of production of iron ore and estimates of reserves of present grade conclude the paper.

  19. Understanding Lateritic Ore Agglomeration Behaviour as a ...


    istics, low grade lateritic ores require more aggressive but costly chemical and hydrometallurgical techniques (e.g., leaching in ... Isothermal, batch agglomeration tests involving 30 and 44 % w/w sulphuric acid ... *Loss of ignition. Table 2: ...

  20. Trace Elements in Fluid Inclusions in the Carlin-Type Gold Deposits, Southwestern Guizhou Province

    苏文超; 胡瑞忠; 漆亮; 方维萱


    Fluid inclusions in quartz from the Lannigou and Yata Carlin-type gold deposits in southwestern Guizhou were analyzed by inductively coupled plasma-mass spectrometry for their trace elements (Co, Ni, Cu, Pb, Zn, Pt, etc. ). The results show that quartz fluid inclusions entrapped at different ore-forming stages contain higher Co, Ni, Cu, Pb and Zn. It has been found for the first time that the ore-forming fluids responsible for the Carlin-type gold deposits are rich in Pt. From this it can be concluded that basic volcanic rocks seem to be one of the im portant sources of ore-forming materials for the Carlin-type gold deposits.

  1. Introduction of Mercury-free Gold Extraction Methods to Medium-Scale Miners and Education of Health Care Providers to Reduce the use of Mercury in Sorata, Bolivia

    Peter W. U. Appel


    Conclusions. The gold ores tested during the project proved amenable to mercury-free gold extraction using borax smelting. The miners also realized that gold recovery increased when performing mercury-free gold extraction. The miners decided to stop using mercury and a follow-up project cleaned their mining equipment for mercury and modified the processing lines. The health care providers were also successfully trained.

  2. Mineralogy and fluid inclusion studies in kalchoye Copper- gold deposit, East of Esfahan

    Rezvan Mehvary


    Full Text Available Kalchoye Copper-gold deposit is located about 110 kilometers east of Esfahan province and within the Eocene volcano sedimentary rocks. Sandy tuff and andesite lava are important members of this complex.The form of mineralization in area is vein and veinlet and quartz as the main gangue phase. The main ore minerals are chalcopyrite, chalcocite, galena and weathered minerals such as goethite, iron oxides, malachite and azurite. Studies in area indicate that ore mineralization Kalchoye is low sulfide, quartz type of hydrothermal ore deposits and results of thermometry studies on quartz minerals low- medium fluid with low potential mineralization is responsible for mineralization in this area.

  3. Analytical fingerprint for tantalum ores from African deposits

    Melcher, F.; Graupner, T.; Sitnikova, M.; Oberthür, T.; Henjes-Kunst, F.; Gäbler, E.; Rantitsch, G.


    Illegal mining of gold, diamonds, copper, cobalt and, in the last decade, "coltan" has fuelled ongoing armed conflicts and civil war in a number of African countries. Following the United Nations initiative to fingerprint the origin of conflict materials and to develop a traceability system, our working group is investigating "coltan" (i.e. columbite-tantalite) mineralization especially in Africa, also within the wider framework of establishing certified trading chains (CTC). Special attention is directed towards samples from the main Ta-Nb-Sn provinces in Africa: DR Congo, Rwanda, Mozambique, Ethiopia, Egypt and Namibia. The following factors are taken into consideration in a methodological approach capable of distinguishing the origin of tantalum ores and concentrates with the utmost probability: (1) Quality and composition of coltan concentrates vary considerably. (2) Mineralogical and chemical compositions of Ta-Nb ores are extremely complex due to the wide range of the columbite-tantalite solid solution series and its ability to incorporate many additional elements. (3) Coltan concentrates may contain a number of other tantalum-bearing minerals besides columbite-tantalite. In our approach, coltan concentrates are analyzed in a step-by-step mode. State-of-the-art analytical tools employed are automated scanning electron microscopy (Mineral Liberation Analysis; MLA), electron microprobe analysis (major and trace elements), laser ablation-ICP-MS (trace elements, isotopes), and TIMS (U-Pb dating). Mineral assemblages in the ore concentrates, major and trace element concentration patterns, and zoning characteristics in the different pegmatites from Africa distinctly differ from each other. Chondrite-normalized REE distribution patterns vary significantly between columbite, tantalite, and microlite, and also relative to major element compositions of columbites. Some locations are characterized by low REE concentrations, others are highly enriched. Samples with

  4. Mechanism of mechanical activation for sulfide ores

    HU Hui-ping; CHEN Qi-yuan; YIN Zhou-lan; HE Yue-hui; HUANG Bai-yun


    Structural changes for mechanically activated pyrite, sphalerite, galena and molybdenite with or without the exposure to ambient air, were systematically investigated using X-ray diffraction analysis(XRD), particle size analysis, gravimetrical method, X-ray photo-electron spectroscopy(XPS) and scanning electron microscopy(SEM), respectively. Based on the above structural changes for mechanically activated sulfide ores and related reports by other researchers, several qualitative rules of the mechanisms and the effects of mechanical activation for sulfide ores are obtained. For brittle sulfide ores with thermal instability, and incomplete cleavage plane or extremely incomplete cleavage plane, the mechanism of mechanical activation is that a great amount of surface reactive sites are formed during their mechanical activation. The effects of mechanical activation are apparent. For brittle sulfide ores with thermal instability, and complete cleavage plane, the mechanism of mechanical activation is that a great amount of surface reactive sites are formed, and lattice deformation happens during their mechanical activation. The effects of mechanical activation are apparent. For brittle sulfide ores with excellent thermal stability, and complete cleavage plane, the mechanism of mechanical activation is that lattice deformation happens during their mechanical activation. The effects of mechanical activation are apparent. For sulfide ores with high toughness, good thermal stability and very excellent complete cleavage plane, the mechanism of mechanical activation is that lattice deformation happens during their mechanical activation, but the lattice deformation ratio is very small. The effects of mechanical activation are worst.

  5. How Many Ore-Bearing Asteroids?

    Elvis, Martin


    A simple formalism is presented to assess how many asteroids contain ore, i.e. commercially profitable material, and not merely a high concentration of a resource. I apply this formalism to two resource cases: platinum group metals (PGMs) and water. Assuming for now that only Ni-Fe asteroids are of interest for PGMs, then 1% of NEOs are rich in PGMs. The dearth of ultra-low delta-v (= US$1 B and the population of near-Earth objects (NEOs) larger than 100 m diameter is ~20,000 (Mainzer et al. 2011) the total population of PGM ore-bearing NEOs is roughly 10. I stress that this is a conservative and highly uncertain value. For example, an order of magnitude increase in PGM ore-bearing NEOs occurs if delta-v can as large as 5.7 km s-1. Water ore for utilization in space is likely to be found in ~1/1100 NEOs. NEOs as small as 18 m diameter can be water-ore-bodies because of the high richness of water (~20%) expected in ~25% of carbonaceous asteroids, bringing the number of water-ore-bearing NEOs to ~9000 out of th...


    GU; Li; DAI; Ta-gen


    Based on the knowing geochemical characteristics of wall rock in the Mobin gold deposit and composition of fluid inclusion in ore,water-rock experiments were carried out,important achievements are acquired as following: Gold is mainly derived from the ore-bearing wall rock,i,e.,a series of epimetamorphic clastic gritstone,sandy slate,and tuffaceous slate in the Wuqiang Banxi Formation,Wuqiangxi Group.In thermal system with middle-low temperature chlorine gold may be derived form stable complex ions,so it is quite important in gold metallogenic process.Sulphur and chlorine perform as the major negative ions throughout the gold activation and migration movement.The concentration of sulphur and chlorine ions,pH value and temperature are of deciding significance for gold activation,migration and precipitation.


    LIU; Liang-ming; PENG; Sheng-lin; YIANG; Qun-zhou; SHAO; Yong-jun; WANG; Zhi-qiang


    This paper discusses the strategy for successfully predicting the location of potential hidden ore bodies in aged ore field,and presents the result of location prediction of hidden ore bodies in Fenghuangshan ore field,Tongling.Innovative conceptual targeting procedures based on a genetic understanding of mineralization systems,carefully geological investigation and correct deduction,together with new geochemical and geophysical technology and integrating of comprehensive information are all very important for the successful prediction.In the aged Fenghuangshan ore field,through researching by application of the metallogenic theory of polygenetic compound ore deposits and triple-frequency induced polarization method and exploration tectono-geochemical method,we predicted location and quality of hidden ore bodies.According to the prediction,hidden high quality Cu-Au ore bodies of skarn type and porphyry type have been discovered.

  8. Major Elements Geochemistry of the Breiner Baiut Ore Deposit (Gutai Mountains, Eastern Carpathians

    Dan Costin


    Full Text Available The Breiner Băiuţ epithermal vein – type deposit is basically a base metal ore body with important amounts of gold and silver. The frequency distribution pattern of the major elements (Au, Ag, Pb, Zn, Cu, S is complex in many cases, but at some mining levels it is lognormal. The correlation coefficient "r" has been calculated for six pairs of major elements. The values are positive and indicate strong correlations between these elements. The average grades values for each major element at all levels have been used to highlight the vertical variation of chemistry of the mineralization. The ore body consists of zones rich in different elements interlayered with poorly mineralized zones.

  9. Quantification of gold and silver in minerals by laser-induced breakdown spectroscopy

    Díaz, Daniel; Hahn, David W.; Molina, Alejandro


    The performance of laser-induced breakdown spectroscopy (LIBS) to identify and quantify gold and silver in ore samples was evaluated. Ores from a gold-producing mine and samples artificially doped with Au and Ag solutions to previously defined concentrations (surrogates) were prepared as 50-mm pellets prior to LIBS analysis. Silver detection and intensity measurement was straightforward for concentrations from 0.4 to 43 μg/g and from 1.1 to 375 μg/g in ore and surrogate samples, respectively. Au emission lines were not found after ensemble average or accumulation of 100-single shot LIBS spectra of ore samples containing up to 9.5 μg/g Au. However, the Au signal was present in the spectra of surrogate samples, for which a detection limit of about 0.8 μg/g was determined. When the number of sampling shots in ore samples increased, various single shot spectra registered Au emission lines. The number of spectra containing Au emission lines increased with the number of single shots. Those results, as well as scanning electron microscopy analysis of ore samples, suggest that the discrete analyte distribution as well as the inherent discrete characteristics associated to LIBS made the presence of gold in the LIBS spark an unlikely occurrence. The particle sampling rates (the percentage of laser pulses expected to sample at least one particle) were estimated for gold concentrations of 1.1 and 10.0 μg/g as 0.04% and 0.32%, respectively. A Monte Carlo simulation indicated that > 100 gold-containing particles should be sampled to accurately represent the discrete character of gold in the ore. Sampling 100 such particles requires > 105 laser pulses over a single pellet. Despite the fact that this rather large number of shots makes difficult to conduct conditional analysis on pellets, for some samples that withstood 5000 shots, gold quantification in ores was successfully achieved at concentrations as low as 1 μg/g. Results are encouraging and illustrate the applicability

  10. Mobility factors of cracked ore in vibrating-ore draw shafts

    WU Ai-xiang; JIANG Li-chun; CHEN Jia-sheng


    The mobile factors of cracked ore in vibrating-ore draw shafts were analyzed. The results show that the mobile coefficient of cracked ores will be mainly influenced by the combination of ore physical factors if the structure dimension and parameters of vibrating ore-draw shafts are sure. It decreases with increasing the cohesion, lump content, lump size and powder content and increases with increasing the porosity. The coefficient decreases with increasing the moisture content, but increases after the moisture content reaches a certain value. Uniform grain leads to better mobility, non-uniform grain leads to worse mobility. The value of the mobile coefficient should be in a range of 0.31.1 when designing the vibrating ore-draw shafts. According to correlation degree of grey system theory, the effects of factors on the mobility of cracked ore are given in the weight decreasing consequence as follows: moisture content, lump content, distribution of grain size, lump size, porosity, cohesion and powder ore content. It is unreasonable to neglect any one because the values of their weights are not obvious.

  11. Contrasting REE Signatures on Manganese Ores of Iron Ore Group in North Orissa, India


    The distribution pattern of Rare Earth Elements (REE) in three categories of manganese ores viz.stratiform, stratabound-replacement, and detrital of Precambrian Iron Ore Group from north Orissa, India was reported.These categories of Mn-ore differed in their major and trace chemistry and exhibited contrasting REE signature.The stratiform ores were relatively enriched in REE content (697 μg·g-1) and their normalized pattern showed both positive Ce and Eu anomalies, whereas the stratabound-replacement types were comparatively depleted in REE content (211 μg·g-1) and showed negative Ce and flat Eu signatures.The detrital categories showed mixed REE pattern.The data plotted in different discrimination diagrams revealed a mixed volcaniclastic and chemogenic source of material for stratiform categories, and LREE (Light Rare Earth Elements) and HREE (Heavy Rare Earth Elements) are contributed by such sources, respectively.In contrast, the stratabound ore bodies were developed during the remobilization of stratiform ores, and associated Mn-containing rocks under supergene condition followed by the redeposition of circulating mineralized colloidal solutions in structurally favorable zones.During this process, some of the constituents were found only in very low concentration within stratabound ores, and this is attributed to their poor leachability/mobility.The detrital ores did not exhibit any significant characteristic in respect of REE as their development was via a complex combination of processes involving weathering, fragmentation, recementation, and burial under soil cover.

  12. Organic Gases in Fluid Inclusions of Ore Minerals and Their Constraints on Ore Genesis: A Case Study of the Changkeng Au-Ag Deposit, Guangdong, China


    The newly discovered Changkeng Au-Ag deposit is a new type of sediment-hosted precious metal deposit. Most of the previous researchers believed that the deposit was formed by meteoric water convection. By using a high vacuum quadrupole gas mass spectrometric system, nine light hydrocarbons have been recognized in the fluid inclusions in ore minerals collected from the Changkeng deposit. The hydrocarbons are composed mainly of saturated alkanes C1-4 and unsaturated alkenes C2-4 and aromatic hydrocarbons, in which the alkanes are predominant, while the contents of alkenes and aromatic hydrocarbons are very low. The Σalka/Σalke ratio of most samples is higher than 100, suggesting that those hydrocarbons are mainly generated by pyrolysis of kerogens in sedimentary rocks caused by water-rock interactions at medium-low temperatures, and the metallogenic processes might have not been affected by magmatic activity. A thermodynamic calculation shows that the light hydrocarbons have reached chemical equilibrium at temperatures higher than 200?C, and they may have been generated in the deep part of sedimentary basins (e.g., the Sanzhou basin) and then be transported by ore-forming fluids to a shallow position of the basin via a long distance. Most of the organic gases are generated by pyrolysis of the type II kerogens (kukersite) in sedimentary host rocks, only a few by microorganism activity. The compositions and various parameters of light hydrocarbons in gold ores are quite similar to those in silver ores, suggesting that the gold and silver ores may have similar metallogenic processes. Based on the compositions of organic gases in fluid inclusions, the authors infer that the Changkeng deposit may be of a tectonic setting of continental rift. The results of this study support from one aspect the authors' opinion that the Changkeng deposit is not formed by meteoric water convection, and that its genesis has a close relationship with the evolution of the Sanzhou basin, so

  13. Mercury use in artisanal small-scale gold mining threatens human health: measures to describe and reduce the health risk

    Steckling, Nadine


    **Background:** Mercury is used in more than 70 countries to extract gold in artisanal small-scale gold mining (ASGM). The application of mercury is simple and plays a key role in the livelihood for more than 16 million gold miners. Mercury is added to the crushed ore and builds an amalgam with the gold it contains. The amalgam is then smelted, the mercury evaporates, and gold remains. The amalgam smelting is the main source of mercury exposure in ASGM. ASGM is the largest anthropogenic sourc...

  14. Metallogenic epoch and genesis of the gold deposits in Jiaodong Peninsula, Eastern China: a regional review

    YANG Liqiang; DENG Jun; GE Liangsheng; WANG Qingfei; ZHANG Jing; GAO Bangfei; JIANG Shaoqing; XU Hao


    Gold deposits are characterized by multi-sources, superimposition, large scale and temporal-spatial concentration in Jiaodong Peninsula, Eastern China. In this paper, we review the history and the development of the study on metallogenic chronology and genesis of gold deposits, summarize the main features of superimposed metallogenesis, provide evidence of the Mesozoic complex metallogenic system, and point out some problems for further research of Jiaodong gold deposit cluster from a regional view. Although gold deposits are different in genetic types, ore-forming materials and geological settings, our research indicates that the accumulation and emplacement of the ore-forming materials are temporally-spatially concentrated on a large scale, and the main metallogenic epoch of Jiaodong gold deposits was concentrated in Mesozoic. Metallogenic chronology and geological-geochemical data indicate that there are two periods of gold mineralizations occurred in 130-110 Ma and 90-80 Ma respectively in Jiaodong ore cluster. The gold deposit cluster results from the superimposition of the polygenetic mineralization, and further study is needed to investigate the formation and evolution of the Mesozoic complex metallogenic system.

  15. A Three—Stage Metallogenic Model for Gold Deposits in Metamorphosed Microclastic Rocks

    王秀璋; 程景平; 等


    Gld deposits occurring in metamorphosed microcelastic rocks are distributed extensively at home and abroad.Some deposits of this type are of superlarge tonnage.The formation of gold deposits in metamorphosed microclastic rocks involves three stages:the sedimentary stage,the regionally metamorphic stage,and the ore-forming stage.At the first stage,microclastic sedimentary source rocks were developed in a relatively semi-enclosed reducing sea basin and were enriched in carbon,sulfur and gold.At the second stage,the gold adsorbed on organic matter and clay minerals was relesed and poorly concentrated during the destruction of organic matter and the depletion of clay minerals by regional metamorphism with increase temperature and pressure.At the third stage,a tectono-hydrothermal event took place.As a result,gold was leached from metamorphosed microclastic rocks,transported to ore depositional locus and/or mixed with gold of other sources in the course of migration,and finally precipitared as ores.Gold deposits of this type were eventually formed at the third stage,and they also can be classified as the orogenic belt type and the activation zone type.The gold deposits occurring in metamorphosed microcalastic rocks are the products of reworking processes and the influence of magmatism should be taken into consideration in some cases.

  16. Selective Flocculation of Dilband Iron Ore, Pakistan

    Muhammad Ishaque Abro


    Full Text Available Selective flocculation for long is known as one of the beneficiation techniques applicable to the concentration of finely disseminated ores. The success of this technique is based on the selective adsorption of an organic polymer on the mineral particles to be flocculated. In present study beneficiation of finely disseminated Dilband iron ore using selective flocculation has been attempted. The effect of pH, sodium silicate (Na2SiO3, sodium hexametaphosphate (Na2OP2O5, sodium trypolyphosphate (Na5P3O10, ethylediaminetretracetae (NaCH2-CH2N, flocculant doses, and flocculant mixing method on the selective adsorption of corn starch on hematite, the chief iron mineral, was studied comprehensively. Improvement in grade was assessed by XRF analysis of the flocculation products. The selective flocculation upgraded the ore from 52% hematite (i.e. 39% Fe to 60% hematite (i.e. 45% Fe with an average hematite recovery of 15%. Appreciable increase in ore grade with sufficiently poor recovery suggested that selective flocculation process is not adequate beneficiating technique to upgrade the Dilband iron ore due to heavily intergrowth of impurities.

  17. Aluminum substitution in goethite in lake ore

    Carlson, L.


    Full Text Available The extent of substitution of Fe by Al in goethite in 32 lake ore samples collected from 11 lakes in Finland varied between 0 and 23 mol-%. The data indicated a negative relationship between Al-substitution and the particle size of lake ore. Differences in the Al-substitution were apparent between sampling sites, suggesting that kinetic and environmental variation in lake ore formation influences the substitution. Non-substituted goethite is formed in coarse-grained sediments with locally high concentrations of Fe due to iron-rich springs. Unit cell edge lengths and volumes of goethite varied as function of Al-subsitution but deviated from the Vegard relationship towards higher values.

  18. Nitrogen isotope and content record of Mesozoic orogenic gold deposits surrounding the North China craton


    As an effective tracer, nitrogen isotopes have been used to determine the source of ore materials in recent years. In this study, the nitrogen isotopes and contents were measured on K- feldspar and sericite of gold deposits and some related granitic intrusions in Jiaodong, Xiaoqinling-Xiong'ershan, west Qinling, the west part of North Qilian and the Zhangjiakou-Xuanhua district around the North China craton (NCC). Although the gold deposits around the NCC are hosted in Precambrian metamorphic rocks, Phanerozoic sedimentary rocks, mafic volcanic rocks or granite, comparison of which with the nitrogen contents and isotope data of previous studies on mantle-derived rocks, granites, metamorphic rocks and gold deposits indicates that those deposits are closely related to granitic rocks. In addition, mantle-derived materials may have been involved in the ore-forming processes to a certain degree. This conclusion is consistent with the result of previous hydrogen, oxygen and carbon isotopic studies of those gold deposits.

  19. Rare Earth Elements Geochemistry of Dongtian Gold Deposit in Western Guangdong



    Yunkai uplifted area is one of the important metallogenic areas in Guangdong and Guangxi Provinces, in which many gold, silver, tungsten, tin, lead, zinc, molybdenum, and iron deposits were found. Dongtian gold deposit in the middle of Yunkai uplifted area, western Guangdong Province, is chosen as an example of those deposits. Comparative studies on the chondrite-normalized REE patterns and ΣREE, LREE/HREE, δEu, δCe, NLa/Yb, and NLa/Sm of auriferous quartz veins, altered gneiss-type gold ores, Caledonian gneissic biotite granite, and Late Yanshanian granite porphyry were made. The results indicate that the source of the metallogenic materials of the auriferous quartz veins and the altered gneiss-type gold ores are the same, and both of them come from the gneissic biotite granite. Metallogenic epoch of the deposit is estimated to be Caledonian period.

  20. The physical hydrogeology of ore deposits

    Ingebritsen, Steven E.; Appold, M.S.


    Hydrothermal ore deposits represent a convergence of fluid flow, thermal energy, and solute flux that is hydrogeologically unusual. From the hydrogeologic perspective, hydrothermal ore deposition represents a complex coupled-flow problem—sufficiently complex that physically rigorous description of the coupled thermal (T), hydraulic (H), mechanical (M), and chemical (C) processes (THMC modeling) continues to challenge our computational ability. Though research into these coupled behaviors has found only a limited subset to be quantitatively tractable, it has yielded valuable insights into the workings of hydrothermal systems in a wide range of geologic environments including sedimentary, metamorphic, and magmatic. Examples of these insights include the quantification of likely driving mechanisms, rates and paths of fluid flow, ore-mineral precipitation mechanisms, longevity of hydrothermal systems, mechanisms by which hydrothermal fluids acquire their temperature and composition, and the controlling influence of permeability and other rock properties on hydrothermal fluid behavior. In this communication we review some of the fundamental theory needed to characterize the physical hydrogeology of hydrothermal systems and discuss how this theory has been applied in studies of Mississippi Valley-type, tabular uranium, porphyry, epithermal, and mid-ocean ridge ore-forming systems. A key limitation in the computational state-of-the-art is the inability to describe fluid flow and transport fully in the many ore systems that show evidence of repeated shear or tensional failure with associated dynamic variations in permeability. However, we discuss global-scale compilations that suggest some numerical constraints on both mean and dynamically enhanced crustal permeability. Principles of physical hydrogeology can be powerful tools for investigating hydrothermal ore formation and are becoming increasingly accessible with ongoing advances in modeling software.

  1. A new radiation shielding material: Amethyst ore

    Korkut, Turgay, E-mail: [Faculty of Science and Art, Department of Physics, Ibrahim Cecen University, Agri (Turkey); Korkut, Hatun [Faculty of Science and Art, Department of Physics, Ibrahim Cecen University, Agri (Turkey); Karabulut, Abdulhalik; Budak, Goekhan [Faculty of Science, Department of Physics, Atatuerk University, Erzurum (Turkey)


    This paper describes a new radiation shielding material, amethyst ore. We have determined the elemental composition of amethyst using WDXRF spectroscopy technique. To see the shielding capability of amethyst for several photon energies, these results have been used in simulation process by FLUKA Monte Carlo radiation transport code. Linear attenuation coefficients have been calculated according to the simulation results. Then, these values have been compared to a fine shielding concrete material. The results show that amethyst shields more gamma beams than concrete. This investigation is the first study about the radiation shielding properties of amethyst ore.


    WU Xiang-bin; DAI Ta-gen; WANG Zhi-bin; FANG Sheng-kui


    The Dachang tin-polymetallic ore field in northern Guangxi,China,lies in a mid-late Paleozoic rift that borders up the southern boundary of the Jiangnan-Xuefeng Massif.As a giant ore deposit,it deposited in middle of the Nandang-Hechi metallogenic zone.The orehosting strata are of the Devonion,which shows the evident characteristics of polymetallic elements,i.e: ,Sn,Zn,Pb,Sb,As,Cu,Ag,In,Ge,Cd,et al.,and over 1 000 000 t tin reserves.

  3. Partitioning properties of rare earth ores in China

    CHI Ru'an; LI Zhongjun; PENG Cui; ZHU Guocai; XU Shengming


    The properties of rare earth partitioning in Chinese industrial rare earth ores were analyzed. Rare earth ores can be divided into the single-mineral type ore with bastnaesite, the multi-mineral type ore with bastnaesite and monazite, and the weathering crust type. Both the Bayan Obo rare earth ore and the Zhushan rare earth ore are a kind of mixed ore, consisting of bastnaesite and monazite. Their rare earth partitionings are strongly enriched in light rare earths, where CeO2 is 50% and the light rare earth partitioning is totally over 95%. The Mianning rare earth ore as well as the Weishan rare earth is a kind of rare earth ore only having bastnaesite. Their rare earth partitionings are also strongly enriched in light rare earths,in which CeO2 is 47% and the light rare earth partitioning is totally over 94%. For the weathering crust type rare earth ore,there are the Longnan rare earth ore, the Xunwu rare earth ore, and the middle yttrium and rich europium ore. In the Longnan rare earth ore, which is strongly enriched in heavy rare earths, Y2O3 is 64.83%, and the heavy and light rare earth partitionings are 89.40% and 10.53%, respectively. In the Xunwu rare earth ore, which is strongly enriched in light rare earths, CeO2 is 47.16%, and the light rare earth partitioning is totally 93.25%. Y and Eu are enriched in the middle yttrium and rich europium ore. Its middle rare earth partitioning is totally over 10%, and Eu2O3 and Y2O3 are over 0.5% and 20%,respectively, which are mainly industrial resources of the middle and the heavy rare earths.

  4. Sintering Properties and Optimal Blending Schemes of Iron Ores

    Dauter0liveira; WUSheng—li; DAIYu—ming; XUJian; CHEN Hong


    In order to obtain good sintering performance, it is important to understand sintering properties of iron ores. Sintering properties including chemical composition, granulation and high-temperature behaviors of ores from China, Brazil and Australia. Furthermore, several indices were defined to evaluate sintering properties of iron ores. The results show that: for chemical composition, Brazilian ores present high TFe, low SiOz, and low Alz03 con- tent. For granulation, particle diameter ratio of Brazilian ores are high; particle intermediate fraction of Chinese con- centrates are low; and average particle size and clay type index of Australian ores are high. For high-temperature properties, ores from China, Brazil and Australia present different characteristics. Ores from different origins should be mixed together to obtain good high-temperature properties. According to the analysis of each ore's sintering prop- erties, an ore blending scheme (Chinese concentrates 20 ~-1- Brazilian ores 400//oo -k Australian ores 40 ~) was sugges- ted. Moreover, sinter pot test using blending mix was performed, and the results indicated that the ore blending scheme led to good sintering performance and sinter quality.

  5. Geochemical explorations for gold deposits at Goldfield, Nevada

    Ashley, Roger P.; Keith, William J.


    The main problem in geochemical exploration for gold ore bodies in the 40 km2 hydrothermally altered area at Goldfield is to decide which of the many silicified ledges exposed are most likely to yield deposits with additional subsurface exploration. We conclude that the most efficient way to search for exploration targets is to collect rock samples from the ledges and analyze for the following elements in decreasing order of priority: gold, lead and silver, bismuth, and mercury. These elements form relict hypogene aureoles restricted to the ledges and are not appreciably redistributed during supergene leaching.

  6. Fire-assay collection of gold and silver by copper.

    Diamantatos, A


    Gold and silver are very effectively collected in copper after fire-assay fusion at 1200 degrees . The resultant copper button is dissolved in perchloric acid and the parting solution is diluted with an equal volume of water. Both gold and silver are precipitated in the copper perchlorate medium by reduction with formic acid or hydroquinone. The two noble metals are collected, dissolved in acids, and determined by atomic-absorption spectrometry. The proposed procedure is simple, relatively rapid, and has been successfully applied to ores, concentrates, furnace products, and copper alloys. Recoveries compare favourably with those obtained by the classical lead cupellation method.

  7. Environmental monitoring at the Nalunaq Gold Mine, South Greenland, 2010

    Glahder, Christian Martin; Søndergaard, Jens; Asmund, Gert

    This seventh monitoring study was performed in the Nalunaq Gold Mine area, Nanortalik, South Greenland during 25-31 August 2010. No ore had been shipped to foreign gold production since the monitoring study in August 2009. Most work has dealt with the excavation of a production chamber...... an uncontaminated area. Samples were analysed for 11 elements with ICP-MS. In lichens, elevated concentrations (2-9 times of background levels) of copper (Cu), chromium (Cr), arsenic (As) and cobalt (Co) were found at the waste rock stockpile and in the mine area. A non-linear temporal trend with decreasing...

  8. A new extraction process of refractory gold arsenosulfide concentrates

    Yuqun Meng; Tao Jin; Minjie Wu; Shaoling Su; Longbao Wang


    A new hydrometallurgical process for the refractory gold arsenosulfide concentrates under normal temperature and pressure was presented. The experimental results of a refractory gold concentrate show that the total consumption of NaOH in alkaline leaching is only 40% of those theoretically calculated under the conditions of full oxidization at the same oxidation of arsenic to arsenate and sulfur to sulfate. After alkaline leaching, cyanidation and adsorption were carried out for 24 h. The dissolution of gold by NaCN is increased to 95.3% from 12.8% before pretreatment, and meanwhile 99.3% of the adsorption of gold by activated charcoal.The consumption of NaCN for one ton ore is 10 kg, which is 1.2 times less than that before pretreatment. As it is carried out under normal temperature and pressure, the investment of installations is also decreased.

  9. The dilemma of the Jiaodong gold deposits:Are they unique?

    Richard J. Goldfarb; M.; Santosh


    The ca. 126e120 Ma Au deposits of the Jiaodong Peninsula, eastern China, define the country’s largest gold province with an overall endowment estimated as>3000 t Au. The vein and disseminated ores are hosted by NE-to NNE-trending brittle normal faults that parallel the margins of ca. 165e150 Ma, deeply emplaced, lower crustal melt granites. The deposits are sited along the faults for many tens of kilometers and the larger orebodies are associated with dilatational jogs. Country rocks to the granites are Pre-cambrian high-grade metamorphic rocks located on both sides of a Triassic suture between the North and South China blocks. During early Mesozoic convergent deformation, the ore-hosting structures developed as ductile thrust faults that were subsequently reactivated during Early Cretaceous “Yan-shanian”intracontinental extensional deformation and associated gold formation. Classification of the gold deposits remains problematic. Many features resemble those typical of orogenic Au including the linear structural distribution of the deposits, mineralization style, ore and alteration assemblages, and ore fluid chemistry. However, Phanerozoic orogenic Au deposits are formed by prograde metamorphism of accreted oceanic rocks in Cordilleran-style orogens. The Jiaodong de-posits, in contrast, formed within two Precambrian blocks approximately 2 billion years after devolati-lization of the country rocks, and thus require a model that involves alternative fluid and metal sources for the ores. A widespread suite of ca. 130e123 Ma granodiorites overlaps temporally with the ores, but shows a poor spatial association with the deposits. Furthermore, the deposit distribution and mineral-ization style is atypical of ores formed from nearby magmas. The ore concentration requires fluid focusing during some type of sub-crustal thermal event, which could be broadly related to a combination of coeval lithospheric thinning, asthenospheric upwelling, paleo-Pacific plate

  10. Timing of ore-related magmatism in the western Alaska Range, southwestern Alaska

    Taylor, Ryan D.; Graham, Garth E.; Anderson, Eric D.; Selby, David


    This report presents isotopic age data from mineralized granitic plutons in an area of the Alaska Range located approximately 200 kilometers to the west-northwest of Anchorage in southwestern Alaska. Uranium-lead isotopic data and trace element concentrations of zircons were determined for 12 samples encompassing eight plutonic bodies ranging in age from approximately 76 to 57.4 millions of years ago (Ma). Additionally, a rhenium-osmium age of molybdenite from the Miss Molly molybdenum occurrence is reported (approx. 59 Ma). All of the granitic plutons in this study host gold-, copper-, and (or) molybdenum-rich prospects. These new ages modify previous interpretations regarding the age of magmatic activity and mineralization within the study area. The new ages show that the majority of the gold-quartz vein-hosting plutons examined in this study formed in the Late Cretaceous. Further work is necessary to establish the ages of ore-mineral deposition in these deposits.

  11. The nature of gold in the Aitik Cu-Au deposit:implications for mineral processing and mine planning

    Sammelin, Monika


    The Aitik mine is a large Cu-Au producer in Europe with an annual production of 28 million tons of ore and a planned expansion of production to 36 million tons of ore until year 2013. Large ongoing investments are done in the mine and a new processing plant is built to manage the capacity increase. The mine is situated 15 kilometers from the town Gällivare, in northern Norrbotten, Sweden. The ore is a large porphyry type deposit with low grades of disseminated copper (0,27 %) and gold (0,16 p...

  12. Element—Assemblage Zoning Features of Gold Deposis in the Cambrian Silicalite Formation,Western Qinling

    刘家军; 郑明华; 等


    The gold deposits,occurring in the south subzone of western Qinling,are the only typical and important strata-bound gold deposits,which are associated with submarine exhalative sedimentation.The gold deposits include the La'erma ore deposit,the Qiongmo ore deposit and the Yaxiang ore occurrence.They are hosted i the Cambrian silicalite formation composed of black chert and slate.The presence of typical chert offers important evidence to evaluate the possible submarine exhalative system and its role in the formation of the gold deposits,which are closely associated with peroclation and diffusion in the horizontal,vertical and axial directions,Element-assemblage zonation is clearly seen due to differences in element concentrations in different directions,Such a zonation makes gold.selenium,uranium,copper,stibium,molybdenum,mercury,etc,precipitate in the form of simple or composite orebodies.The establishent of the element-assemblage zonation is highly helpful for evaluating directly the metallogenesis of gold deposits.


    Fabiana Fonseca Fortes


    Full Text Available This paper aims to identify handling and storage impact in iron ore quality, in their physical and chemical characteristics most important for a mining. It is tried to show the interferences in iron ore quality caused by the handling equipment and stockpiling. The research is restricted to Complexo Vargem Grande (Vale. The timeline was demarcated based on the formation of stockpiling. The fieldwork enables data collection and distinction of the routine procedures of casual operations handling. The quantitative analysis is conducted by the statistical method. As a conclusion, handling and storage identified are able to insert changes in physical and chemical characteristics of iron ore. Storage contributes to reduce variability of silica and alumina concentrations, but contributes too particle size deterioration. The handling induces degradation and segregation. However, there is the possibility to decrease handling of the ore and to establish the ideal size of stocks on the system in study, improving the efficiency of the system and consequent in global costs.

  14. Sources of ores of the ferroalloy metals

    Burchard, E.F.


    Since all steel is made with the addition of alloying elements, the record of the metallic raw materials contributory to the steel industry would be far from complete without reference to the ferroalloy metals. This paper, therefore, supplements two preceding arvicles on the sources of our iron ores. The photographs, with the exception of those relating to molybdenum and vanadium, are by the author.

  15. Mining and processing of uranium ores at the Streltsovsky ore field

    Ovseytchuk, V.A.; Litvinenko, V.G.; Kultishev, V.I. [Joint Stock Company, Priargunsky Industrial Mining and Chemical Union, Krasnokamensk, Chita Region (Russian Federation)


    The uranium deposits of Streltsovsky ore fields provide raw materials for Russian nuclear industry. For this region, it is important to achieve continued and increased activities in the recovery of mineral resources of uranium. Similarly, maintaining the mining and processing of uranium ores ensures the supply of raw materials for the nuclear industry. With the current operations, increasing the mining and processing activities would increase the cost of production of uranium oxides due to decreasing grades of ore body. After a review of the existing economic, technological and natural factors, a solution was proposed based on the joint application of underground mining and ore enrichment and processing with the help of hydrometallurgical process, in-situ leaching. Reduction of operation coasts and creation of radiation-safe working conditions could be achieved with the application of these systems involving concrete hardening in the mines and in-situ leaching of ore. With the help of economic-mathematical modeling, methods for rational application of various technologies could be determined and their processing parameters were specified. A reduction of coasts could be obtained and favorable conditions could be established for improvement in the treatment of lower grade ores by heap leaching. Application of purification of mine waters and tailing pond reduces the influence of the radiation and the impact on the natural environment. (author)

  16. Hydrogen Reduction of Hematite Ore Fines to Magnetite Ore Fines at Low Temperatures

    Wenguang Du


    Full Text Available Surplus coke oven gases (COGs and low grade hematite ores are abundant in Shanxi, China. Our group proposes a new process that could simultaneously enrich CH4 from COG and produce separated magnetite from low grade hematite. In this work, low-temperature hydrogen reduction of hematite ore fines was performed in a fixed-bed reactor with a stirring apparatus, and a laboratory Davis magnetic tube was used for the magnetic separation of the resulting magnetite ore fines. The properties of the raw hematite ore, reduced products, and magnetic concentrate were analyzed and characterized by a chemical analysis method, X-ray diffraction, optical microscopy, and scanning electron microscopy. The experimental results indicated that, at temperatures lower than 400°C, the rate of reduction of the hematite ore fines was controlled by the interfacial reaction on the core surface. However, at temperatures higher than 450°C, the reaction was controlled by product layer diffusion. With increasing reduction temperature, the average utilization of hydrogen initially increased and tended to a constant value thereafter. The conversion of Fe2O3 in the hematite ore played an important role in the total iron recovery and grade of the concentrate. The grade of the concentrate decreased, whereas the total iron recovery increased with the increasing Fe2O3 conversion.

  17. Hydrogen Plasma Processing of Iron Ore

    Sabat, Kali Charan; Murphy, Anthony B.


    Iron is currently produced by carbothermic reduction of oxide ores. This is a multiple-stage process that requires large-scale equipment and high capital investment, and produces large amounts of CO2. An alternative to carbothermic reduction is reduction using a hydrogen plasma, which comprises vibrationally excited molecular, atomic, and ionic states of hydrogen, all of which can reduce iron oxides, even at low temperatures. Besides the thermodynamic and kinetic advantages of a hydrogen plasma, the byproduct of the reaction is water, which does not pose any environmental problems. A review of the theory and practice of iron ore reduction using a hydrogen plasma is presented. The thermodynamic and kinetic aspects are considered, with molecular, atomic and ionic hydrogen considered separately. The importance of vibrationally excited hydrogen molecules in overcoming the activation energy barriers, and in transferring energy to the iron oxide, is emphasized. Both thermal and nonthermal plasmas are considered. The thermophysical properties of hydrogen and argon-hydrogen plasmas are discussed, and their influence on the constriction and flow in the of arc plasmas is considered. The published R&D on hydrogen plasma reduction of iron oxide is reviewed, with both the reduction of molten iron ore and in-flight reduction of iron ore particles being considered. Finally, the technical and economic feasibility of the process are discussed. It is shown that hydrogen plasma processing requires less energy than carbothermic reduction, mainly because pelletization, sintering, and cokemaking are not required. Moreover, the formation of the greenhouse gas CO2 as a byproduct is avoided. In-flight reduction has the potential for a throughput at least equivalent to the blast furnace process. It is concluded that hydrogen plasma reduction of iron ore is a potentially attractive alternative to standard methods.

  18. Hydrogen Plasma Processing of Iron Ore

    Sabat, Kali Charan; Murphy, Anthony B.


    Iron is currently produced by carbothermic reduction of oxide ores. This is a multiple-stage process that requires large-scale equipment and high capital investment, and produces large amounts of CO2. An alternative to carbothermic reduction is reduction using a hydrogen plasma, which comprises vibrationally excited molecular, atomic, and ionic states of hydrogen, all of which can reduce iron oxides, even at low temperatures. Besides the thermodynamic and kinetic advantages of a hydrogen plasma, the byproduct of the reaction is water, which does not pose any environmental problems. A review of the theory and practice of iron ore reduction using a hydrogen plasma is presented. The thermodynamic and kinetic aspects are considered, with molecular, atomic and ionic hydrogen considered separately. The importance of vibrationally excited hydrogen molecules in overcoming the activation energy barriers, and in transferring energy to the iron oxide, is emphasized. Both thermal and nonthermal plasmas are considered. The thermophysical properties of hydrogen and argon-hydrogen plasmas are discussed, and their influence on the constriction and flow in the of arc plasmas is considered. The published R&D on hydrogen plasma reduction of iron oxide is reviewed, with both the reduction of molten iron ore and in-flight reduction of iron ore particles being considered. Finally, the technical and economic feasibility of the process are discussed. It is shown that hydrogen plasma processing requires less energy than carbothermic reduction, mainly because pelletization, sintering, and cokemaking are not required. Moreover, the formation of the greenhouse gas CO2 as a byproduct is avoided. In-flight reduction has the potential for a throughput at least equivalent to the blast furnace process. It is concluded that hydrogen plasma reduction of iron ore is a potentially attractive alternative to standard methods.

  19. Black gold

    Fletcher, MW


    Following the Yom Kippur war of October 1973, OPEC raises the price of oil by 70% along with a 5% reduction in oil production. Len Saunders a highly skilled and knowledgeable British engineer for Jaguar motors, is approached by the UK energy commission in the January of 1974 to create a new propulsion system; using a secret document from a German WW2 scientist, that they have come into possession of. Len Saunders sets to work on creating the holy grail of energy. Seven years later 1981, Haidar Farooq the Kuwait oil minister working at OPEC and head of a secret organisation named Black Gold bec

  20. Geochemistry, Geochronology and Genesis of Gold Mineralization in Nurt of Northern Altay, Xinjiang:A Case Study on the Aketishikan Gold Deposit

    YUAN Feng; ZHOU Taofa; TAN Lugui; LUO Xianrong; YUE Shucang


    Gold deposits such as the Aketishikan, Togetobie, Tasbig-Kokeydlas, Kums and Hongshanzui gold deposits in the Nurt area in Altay of Xinjiang were found in Member 3 rhyolite tufflava, fragmental lava and ignimbrite of the Carboniferous Hongshanzui Group. Trace and rare earth elements, sulfur, lead, oxygen and hydrogen isotopes, and geochronological studies indicate that the ore-forming material was mostly supplied by the Carboniferous volcanic rocks through water-rock interaction under a low-to-moderate temperature, and the hydrothermal ore-forming fluid came from meteoric water with some magmatic water input evolved from the granitic magmas. Gold deposits in the Nurt area as well as in the northern Altay might form in multiple stages, and the Yanshanian mineralization period should be paid more attention besides the Variscan mineralization period.

  1. High-rate behaviour of iron ore pellet

    Gustafsson Gustaf


    Full Text Available Iron ore pellets are sintered, centimetre-sized spheres of ore with high iron content. Together with carbonized coal, iron ore pellets are used in the production of steel. In the transportation from the pelletizing plants to the customers, the iron ore pellets are exposed to different loading situations, resulting in degradation of strength and in some cases fragmentation. For future reliable numerical simulations of the handling and transportation of iron ore pellets, knowledge about their mechanical properties is needed. This paper describes the experimental work to investigate the dynamic mechanical properties of blast furnace iron ore pellets. To study the dynamic fracture of iron ore pellets a number of split Hopkinson pressure bar tests are carried out and analysed.

  2. Going for Gold


    While the international gold price in February hit the highest point in 25 years at $541.20 per ounce for futures delivery, a new gold rush is sweeping across China. According to the World Gold Council, the London-based gold marketing organization funded by leading global gold mining firms, the purchase of gold products in China grew by 9 percent in the first nine

  3. Geochemical Characteristics of the Jinjiazhuang Ultrabasic Rock—Type Gold Deposit in Chicheng County,Hebei Province

    李红阳; 杨竹森; 等


    The Jinjiazhuang gold deposit occurs in the Zhangjiakou gold field,Northwest Hebei.The ore bodies are mostly hosted in Xiaozhangjiakou ultrabasic rocks dominated by diopsidite.Electron microprobe analyses indicate that the deposit is characterized by the enrichment of some platinum group elements in principal metallic minerals such as chalcopyrite,galena,sphalerite and pyrite,and the presence of millerite,Stable isotope studies show that carbon,sulfur and most of the metallogenic elements were probably derived largely from the host Xiaozhangjiakou ultrabasic rocks and that it is possible that the ore-forming fluid was predominted by meteoric water.

  4. Sr Isotope Constraints on the Age and Source of Ore—Forming Materials of Gold Deposits,Southwestern Hunan

    彭建堂; 戴塔根; 等


    We have measured Rb and Sr concentrations in fluid inclusions of quartz in gold deposits,southwestern Hunan,The Rb-Sr isochron ages of 435±9Ma and 412±33Ma are respectively determined,revealing that gold mineralization in this area took place in the Caledonian period rather than in the Wuling-Xuefeng period as traditionalyy considered.Sr isotope geochemistry of the hydrothermal fluid indicates that the ore-forming materials are of crust origin,derived largely from the ore-hositng strata rather than from the basic dikes.

  5. Decrepitation Thermometry and Compositions of Fluid Inclusions of the Damoqujia Gold Deposit,Jiaodong Gold Province,China:Implications for Metallogeny and Exploration

    Yang Liqiang; Deng Jun; Zhang Jing; Guo Chunying; Gao Bangfei; Gong Qingjie; Wang Qingfei; Jiang Shaoqing; Yu Haijun


    The recently discovered Damoqujia (大磨曲家) gold deposit is a large shear zone-hosted gold deposit of disseminated sulphides located in the north of the Zhaoping (招平) fault zone, Jiaodong (胶东) gold province, China. In order to distinguish the temperature range of cluster inclusions from different mineralization stages and measure their compositions, 16 fluid inclusions and 5 isotopic geochemistry samples were collected for this study. Corresponding to different mineralization stages, the multirange peaks of quartz decrepitation temperature (250-270, 310-360 and 380-430℃(2) indicate that the activity of ore-forming fluids is characterized by multistage. The ore-forming fluids were predominantly of high-temperature fluid system (HTFS) by CO2-rich, and SO2-4-K+ type magmatic fluid during the early stage of mineralization and were subsequently affected by low-temperature fluid system (LTFS) of CH4-rich, and Cl--Na+/Ca2+ type meteoric fluid during the late stage of mineralization. Gold is transferred by Au-HS- complex in the HTFS, and Au-Cl- complex can be more important in the LTFS. The transition of fluids from deeper to shallow environments results in mixing between the HTFS and LTFS, which might be one of the most key reasons for gold precipitation and large-scale mineralization. The ore-forming fluids are characterized by high-temperature, strong-activity, and superimposed mineralization, so that there is a great probability of forming large and rich ore deposit in the Damoqujia gold deposit. The main bodies are preserved and extend toward deeper parts, thereby suggesting a great potential in future.

  6. ASTER, ALI and Hyperion sensors data for lithological mapping and ore minerals exploration.

    Beiranvand Pour, Amin; Hashim, Mazlan


    This paper provides a review of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Advanced Land Imager (ALI), and Hyperion data and applications of the data as a tool for ore minerals exploration, lithological and structural mapping. Spectral information extraction from ASTER, ALI, and Hyperion data has great ability to assist geologists in all disciplines to map the distribution and detect the rock units exposed at the earth's surface. The near coincidence of Earth Observing System (EOS)/Terra and Earth Observing One (EO-1) platforms allows acquiring ASTER, ALI, and Hyperion imagery of the same ground areas, resulting accurate information for geological mapping applications especially in the reconnaissance stages of hydrothermal copper and gold exploration, chromite, magnetite, massive sulfide and uranium ore deposits, mineral components of soils and structural interpretation at both regional and district scales. Shortwave length infrared and thermal infrared bands of ASTER have sufficient spectral resolution to map fundamental absorptions of hydroxyl mineral groups and silica and carbonate minerals for regional mapping purposes. Ferric-iron bearing minerals can be discriminated using six unique wavelength bands of ALI spanning the visible and near infrared. Hyperion visible and near infrared bands (0.4 to 1.0 μm) and shortwave infrared bands (0.9 to 2.5 μm) allowed to produce image maps of iron oxide minerals, hydroxyl-bearing minerals, sulfates and carbonates in association with hydrothermal alteration assemblages, respectively. The techniques and achievements reviewed in the present paper can further introduce the efficacy of ASTER, ALI, and Hyperion data for future mineral and lithological mapping and exploration of the porphyry copper, epithermal gold, chromite, magnetite, massive sulfide and uranium ore deposits especially in arid and semi-arid territory.

  7. Singular value decomposition (SVD for extraction of gravity anomaly associated with gold mineralization in Tongshi gold field, Western Shandong Uplifted Block, Eastern China

    B. B. Zhao


    Full Text Available A singular value decomposition (SVD program on MATLAB platform was effectively used to handle gravity signals for the Tongshi gold field. Firstly, the gravity signals were decomposed into different eigenimages with the help of singular value decomposition method (SVD. Secondly, the thresholds between the eigenvalues reflecting different layers of ore-controlling factors were established by multi-fractal method. Finally images reflecting different layers of ore-controlling factors were rebuilt. This yielded two layers of two-dimensional singular value images that depict regional and local ore-controlling factors, respectively.

    1. The regional ore-controlling factor is a saddle valley with the gravity anomaly values varying from −55 to 51 μm s−2 on the NW trending swell with the gravity anomaly values varying from −55 to 567 μm s−2 on the SW side of the Mesozoic volcanic sedimentary basin with the gravity anomaly values varying from −56 to −974 μm s−2. The saddle valley might be tectonically an extensional area where the Tongshi complex pluton and all gold deposits are located and thus this area is favorable for gold deposits.

    2. The local ore-controlling factor is the Tongshi complex pluton with a negative circular gravity anomaly varying from −339 to −11 μm s−2 and the ring contact metasomatic mineralization zone around the Tongshi complex with the positive gravity anomaly varying from 37 to 345 μm s−2. The skarn and porphyry types of gold deposits are located within the complex pluton and the Carlin and cryptobreccia types of gold deposits are located within the contact metasomatic mineralization zone. Thus both of them are potential areas for gold deposits.

    3. The Tongshi gold field exhibits a typical complexity with multi-layers of ore-controlling factors.

  8. Gold and tin of fluid-magmatic systems: causes of combination-separation of concentration elements

    I.I. Fatyanov; V.G. Khomich


    The aim of the investigation is to reveal possible causes of isolation and co-occurrence of the economically significant concentrations of gold and tin. Comparative analysis of the different-rank factors that influenced migration and concentration of these elements show that different geochemical properties of Au and Sn are responsible for isolation of their big concentrations giving rise to independent metallogenic provinces, zones, and ore nodes. These differences resulted in individualization of the element migration ways to the level of ore concentration within the fluid-magmatic columns. Three main factors influenced the Au and Sn migration activity: different patterns of metal connection with the melt structure, different relation with oxygen, and different relation with other strong oxidizers. By the moment when ore-bearing fluid became isolated from magmas, the metallogenic signature of the melts, contrasting in redox-potential, had already been defined that was confirmed by the fact that tin ores associate predominantly with the granitoids of ilmenite series and gold ores - with those of magnetite series. The fluid-magmatic systems with an intermediate degree of the melt reduction-oxidation may be considered the potential producers of the combined metal concentrations. In these cases, the combined concentrating of tin and gold is plagued by an opposite direction of the oxidation-reduction reactions when their most common minerals are formed: the main migration form of Sn +2 must be oxidized (with cassiterite portioning), and the forms of Au + or Au +3 must be reduced (with native gold portioning). Probably, because of this the combined tin and gold concentrations are dominated by one of the metals with a tendency of accumulation in different-stage mineral complexes.

  9. Gold in Modern Economy

    Boryshkevych Olena V.


    Full Text Available The article studies the role of gold in modern economy. It analyses dynamics and modern state of the gold market. It studies volumes of contracts in exchange and off-exchange markets. In order to reveal changes of key features of the gold market, it focuses on the study of gold demand volumes, studies volumes and geographical changes in the world gold mining, and analyses volumes of monetary gold of central banks and its share in gold and currency reserves. It analyses price fluctuations in the gold market during 1968 – 2013 and identifies main factors that determine the gold price. It identifies interconnection between the state of the gold market and financial markets of countries. The study showed that namely geopolitical and economic instability restricts the spectrum of financial assets for investing and gold is not only a safe investment object but also a profitable one.

  10. Metallogenesis of the Ertix gold belt, Xinjiang and its rela-tionship to Central Asia-type orogenesis


    The Ertix gold belt is located on the boundary of the Kalatongkearc and the Kelan back-arc basin of D-C1. Most scholars used to interpret the formation and distribution of the gold deposits in the Ertix tectonic belt in terms of the petrogenic and metallogenic models for active continental margins. However, enormous data of isotopic dating and geologic research show that the mineralization was obviously later than the oceanic subduction, whereas exactly simultaneous with the collisional orogenesis during C2-P, especially at the transition stage from collisional compression to extension. Based on study of metallogenic time, tectonic background, ore geology, ore fluid nature, ore material source, etc., we reveal that all the gold deposits possess the character of orogenic deposits formed in collisional orogenic system, and that their ore-forming materials mainly have derived from the stratigraphic terranes south to individual deposits. Accordingly, the theoretical tectonic model for collisional metallogenesis and petrogenesis is employed to explain the formation of the Ertix gold belt and to determine the gold exploration directions.

  11. Dose calculations for intakes of ore dust

    O`Brien, R.S


    This report describes a methodology for calculating the committed effective dose for mixtures of radionuclides, such as those which occur in natural radioactive ores and dusts. The formulae are derived from first principles, with the use of reasonable assumptions concerning the nature and behaviour of the radionuclide mixtures. The calculations are complicated because these `ores` contain a range of particle sizes, have different degrees of solubility in blood and other body fluids, and also have different biokinetic clearance characteristics from the organs and tissues in the body. The naturally occurring radionuclides also tend to occur in series, i.e. one is produced by the radioactive decay of another `parent` radionuclide. The formulae derived here can be used, in conjunction with a model such as LUDEP, for calculating total dose resulting from inhalation and/or ingestion of a mixture of radionuclides, and also for deriving annual limits on intake and derived air concentrations for these mixtures. 15 refs., 14 tabs., 3 figs.

  12. Analysis of geological characteristics,ore-controlling factors and prospecting potentialsin Niuweipo Gold Deposit in Western Hunan%湘西牛尾坡金矿床地质特征、控矿因素及找矿前景分析

    刘焕军; 符海华


    湘西牛尾坡金矿床产于板溪群马底驿组,赋矿岩性为灰白色硅化砂岩。其顶板、底板均为灰绿色粉砂质板岩夹灰绿色变质砂岩及紫红色粉砂质板岩。金矿体均产于马底驿组的灰白色硅化砂岩中;单个矿体长60~200余m,厚度0.49~5.65 m,平均厚度1.7 m;金平均品位4.1×10-6以上,主矿体最大控制斜深已达到680余m;矿体呈柱状、透镜状、薄饼状、脉状产出,矿脉(体)产状与地层产状一致。研究表明,牛尾坡金矿床成因类型是属于层间破碎蚀变石英脉型金矿床,矿床严格受地层、岩性及构造因素控制;矿床已达到中型规模,在该矿区深部、东部及外围(矿区南部F18、F26附近)具有大型以上规模金矿床的找矿前景。%Niuweipo Gold Deposit in Yuanling County occurs in the gray silicified sandstone of Madiyi Formation, Banxi Group.The roof and the bottom are sage-green silty slate plus sage-green meta-sandstone and mauve silty slate. All gold orebodies occur in the gray silicified sandstone of Madiyi Formation.The length of a single orebody is 60-200 meters,and the thickness is 0.49-5.65 meters (average 1.70 meters).The average gold grade is 4.1 ×10 -6 or above.The maximum controlling depth in dip for the major orebody is 680 meters.The shapes of the orebodies are co-lumnar,lenticular,pancake-like and vein.The occurrence of the veins ( orebodies) is consistent with the strata.The study indicates that the genetic type of Niuweipo Gold Deposit is quartz vein with interlayered broken alteration.The deposit is strictly controlled by strata,rock properties and structures.It is a medium-sized deposit.It has prospecting potentials for large scale deposits in the deep area,east area and surrounding area ( southern area near F18 ,F26 ) .

  13. Genetic Pd, Pt, Au, Ag, and Rh mineralogy in Noril'sk sulfide ores

    Spiridonov, E. M.; Kulagov, E. A.; Serova, A. A.; Kulikova, I. M.; Korotaeva, N. N.; Sereda, E. V.; Tushentsova, I. N.; Belyakov, S. N.; Zhukov, N. N.


    The undeformed ore-bearing intrusions of the Noril'sk ore field (NOF) cut through volcanic rocks of the Late Permian-Early Triassic trap association folded in brachysynclines. Due to the nonuniform load on the roof of intrusive bodies, most sulfide melts were squeezed, up to the tops of ore-bearing intrusions; readily fusible Ni-Fe-Cu sulfide melts were almost completely squeezed. In our opinion, not only one but two stages of mineralization developed at the Noril'sk deposits: (i) syntrap magmatic and (ii) epigenetic post-trap metamorphic-hydrothermal. All platinum-group minerals (PGM) and minerals of gold are metasomatic in the Noril'sk ores. They replaced sulfide solid solutions and exsolution structures. All types of PGM and Au minerals occur in the ores, varying in composition from pyrrhotite to chalcopyrite, talnakhite, mooihoekite, and rich in galena; they are localized in the inner and outer contact zones and differ only in the quantitative proportions of ore minerals. The aureoles of PGM and Au-Ag minerals are wider than the contours of sulfide bodies and coincide with halos of fluid impact on orebodies and adjacent host rocks. The pneumatolytic PGM and Au-Ag minerals are correlated in abundance with the dimensions of sulfide bodies. Their amounts are maximal in veins of late fusible ore composed of eutectic PbS ss and iss intergrowths, as well as at their contacts. The Pd and Pt contents in eutectic sulfide ores of NOF are the world's highest. In the process of noble-metal mineral formation, the fluids supply Pd, Pt, Au, As, Sb, Sn, Bi, and a part of Te, whereas Fe, Ni, Cu, Pb, Ag, Rh, a part of Te and Pd are leached from the replaced sulfide minerals. The pneumatolytic PGM of the early stage comprises Pd and Pt intermetallic compounds enriched in Au along with Pd-Pt-Fe-Ni-Cu-Sn-Pb(As) and (Pd,Pt,Au)(Sn,Sb,Bi,Te,As) solid solutions. Pneumatolytic PGM and Au minerals of the middle stage are products of solid-phase transformation and recrystallization of

  14. Orogenic gold and geologic time: A global synthesis

    Goldfarb, R.J.; Groves, D.I.; Gardoll, S.


    Orogenic gold deposits have formed over more than 3 billion years of Earth's history, episodically during the Middle Archean to younger Precambrian, and continuously throughout the Phanerozoic. This class of gold deposit is characteristically associated with deformed and metamorphosed mid-crustal blocks, particularly in spatial association with major crustal structures. A consistent spatial and temporal association with granitoids of a variety of compositions indicates that melts and fluids were both inherent products of thermal events during orogenesis. Including placer accumulations, which are commonly intimately associated with this mineral deposit type, recognized production and resources from economic Phanerozoic orogenic-gold deposits are estimated at just over one billion ounces gold. Exclusive of the still-controversial Witwatersrand ores, known Precambrian gold concentrations are about half this amount. The recent increased applicability of global paleo-reconstructions, coupled with improved geochronology from most of the world's major gold camps, allows for an improved understanding of the distribution pattern of orogenic gold in space and time.

  15. Iron ore weathering potentials of ectomycorrhizal plants.

    Adeleke, R A; Cloete, T E; Bertrand, A; Khasa, D P


    Plants in association with soil microorganisms play an important role in mineral weathering. Studies have shown that plants in symbiosis with ectomycorrhizal (ECM) fungi have the potential to increase the uptake of mineral-derived nutrients. However, it is usually difficult to study many of the different factors that influence ectomycorrhizal weathering in a single experiment. In the present study, we carried out a pot experiment where Pinus patula seedlings were grown with or without ECM fungi in the presence of iron ore minerals. The ECM fungi used included Pisolithus tinctorius, Paxillus involutus, Laccaria bicolor and Suillus tomentosus. After 24 weeks, harvesting of the plants was carried out. The concentration of organic acids released into the soil, as well as potassium and phosphorus released from the iron ore were measured. The results suggest that different roles of ectomycorrhizal fungi in mineral weathering such as nutrient absorption and transfer, improving the health of plants and ensuring nutrient circulation in the ecosystem, are species specific, and both mycorrhizal roots and non-mycorrhizal roots can participate in the weathering process of iron ore minerals.

  16. Vertical mill simulation applied to iron ores

    Douglas Batista Mazzinghy


    Full Text Available The application of vertical mills in regrind circuits is consolidated. This type of mill is now attracting interest in primary grinding applications, due to its higher efficiency when compared to ball mills, which are usually used at this stage. In this study, a coarse sample of iron ore was tested in a pilot scale grinding circuit with a vertical mill. Other three samples of pellet feed had already been tested with the methodology used in this study. The sample of coarse iron ore was characterized in laboratory tests carried out in a small batch ball mill. Selection and breakage function parameters were determined from the laboratory tests. The parameters were then used for simulating the pilot scale tests using Modsim™ software. The model previously implemented in Modsim™ has been successfully applied to represent the vertical mill operated with different ores. The simulations produced particle size distributions that were very close to the actual size distributions, and the predictions were accomplished only by imputing the calibrated parameters from the batch tests, the power draw and the feed size distribution of the pilot tests. The methodology is therefore useful for scale-up and simulation of vertical mills, only requiring laboratory tests that can be carried out in standard laboratory batch ball mills with small amounts of samples.

  17. Synchrotron radiation X-ray fluorescence analysis on altered mineral muscovite in gold deposit

    TANG Yun-Hui; YUAN Wan-Ming; WANG Li-Hua; HAN Chun-Ming; HUANG Yu-Ying; HE Wei


    Synchrotron radiation X-ray fluorescence (SRXRF) microprobe was used to ananlyse altered mineral muscovite and its surrounding feldspar in Yuerya gold deposit. The major, minor and trace elements of the two minerals were detected and analyzed. SRXRF analysis showed that the Yuerya muscovite had a complex chemical composition, containing K, Fe, Ca, Ti, Cr, Mn, Co, Cu, Zn and many trace or ultra-trace elements. Since muscovite resulted from the alteration of hydrothermal ore fluid acting on feldspar (plagioclase), the difference of chemical composition between the two minerals shows the components of ore fluid, which are characterized by the enrichment of alkaline and alkaline-earth metal elements K, Ca and ore-associated elements Fe, Cu, Zn. And gold, silver and platinum, invisible under microscope, were detected in some areas of muscovite, but not found in feldspar. Especially platinum, a mantle material, is rarely seen in the earth crust but now found in the gold deposit of magmatic sources; its appearance approves the idea of mantle flux participating in the gold mineralization, which suggests that the tectonic event controlling gold mineralization in the Yuerya district is a mantle phenomenon.

  18. Early Yellowstone hotspot magmatism and gold metallogeny

    Hames, Willis; Unger, Derick; Saunders, James; Kamenov, George


    High-grade epithermal gold deposits in the Northern Great Basin have long been associated with regional Miocene basaltic to rhyolitic volcanism. Previous models for the low-sulfidation epithermal gold ores in this region have generally portrayed the bimodal magmas as a source of heat to drive large-scale convection of meteoritic water that leached gold from crustal sources and deposited it in hydrothermal vein systems, or required that the gold evolve from fractionated silicic magmas. New data of the present study indicate a more direct genetic link to the plume-related basaltic magmas of the region. Laser 40Ar/ 39Ar incremental heating plateau ages for single crystals of adularia from several of these low-sulfidation epithermal gold deposits range from 16.6 Ma to 15.5 Ma. Adularia from the Jumbo deposit yields three concordant plateau ages with a combined statistical result of 16.54 ± 0.04 Ma (95% confidence level, MSWD = 0.23). Plateau ages for adularia from other deposits in the region, and from gold-bearing veins in the Owyhee Mountains of southwestern Idaho, yield similar ages up to ~16.5 Ma, however some veins are as young as ca. 15.5 Ma and the grain-to-grain ages for a given sample can vary by up to ca. 0.5 Ma. Observed variations in age among the adularia crystals of a given rock sample indicate varying amounts of extraneous argon, and also loss of radiogenic 40Ar, among the population of grains for a particular sample. The single-crystal results are interpreted to indicate a 16.5-15.5 Ma interval for formation of gold-bearing adularia veins in the region. The initiation and duration of this gold-forming event appears contemporaneous (within uncertainties) with the basaltic volcanism at the Steens Mountain section and an ensuing one-million-year episode of basaltic volcanism from multiple centers in the region ( Brueseke et al., 2007). Trace amounts of lead are alloyed with gold in the deposits studied. The isotopic compositions of this lead are not

  19. Isotopic Characteristics of Mesozoic Au-Ag Polymetallic Ore Deposits in Northern Hebei and Their Ore-Forming Materials Source

    王宝德; 牛树银; 孙爱群; 李红阳


    It has long been a controversy about the source of ore-forming materials of Au-Agpolymetallic deposits both in metallogenic theory and in ore-searching practice. In terms of alarge wealth of the isotopic statistics data from Indosinian-Yanshanian endogenic ore deposits innorthern Hebei (generally referring to the areas along the northern part of Taihang Mountainsand northern Hebei, the same below) , it is considered that the ore-forming materials came fromthe deep interior of the Earth, which had migrated through plumes to the Earth surface while ex-perienced multi-stage evolution and then emplaced progressively in favorable structural loci toform ores. Their isotope data show that 559 sulfur isotopic data from 40 ore deposits are, for themost part, within the range of - 5‰ - 5‰, with a high degree of homogenization, indicatingthat the sulfur is derived mainly from magma; 200 lead isotope data from 37 ore deposits indi-cate that the ore-forming materials are principally of mantle source though some crust-source ma-terial was involved; 96 oxygen, hydrogen and carbon isotope data from 34 ore deposits illustratethat the ore-forming fluids are dominated by magmatic water while other sources of water wouldbe involved. It may therefore be seen that the formation of endogenic deposits has nothing to dowith the strata.

  20. Physical-chemical conditions of ore deposition

    Barton, P.B.


    Ore deposits form under a wide range of physical and chemical conditions, but those precipitating from hot, aqueous fluids-i.e. the hydrothermal deposits-form generally below 700??C and at pressures of only 1 or 2 kbar or less. Natural aqueous fluids in rocks may extract metal and sulfur from a variety of rock types or may acquire them as a residual heritage from a crystallizing silicate magma. Ore-forming hydrothermal fluids never appear as hot springs (except in deep, submarine situations) because they boil, mix with surface waters, and cool, thereby losing their ore-bearing ability before reaching the surface. Mineral systems function as chemical buffers and indicators just as buffers and indicators function in a chemical laboratory. By reading the record written in the buffer/indicator assemblages of minerals one can reconstruct many aspects of the former chemical environment. By studying the record of changing conditions one may deduce information regarding the processes functioning to create the succession of chemical environments and the ore deposits they represent. The example of the OH vein at Creede, Colorado, shows a pH buffered by the K-feldspar + muscovite + quartz assemblage and the covariation of S2 and O2 buffered by the assemblage chlorite + pyrite + quartz. Boiling of the ore fluid led to its oxidation to hematite-bearing assemblages and simultaneously produced an intensely altered, sericitic capping over the vein in response to the condensation of vapors bearing acidic components. The solubility of metals as calculated from experimental and theoretical studies of mineral solubility appears too low by at least one or two powers of ten to explain the mineralization at Creede. In contrast to Creede where the mineral stabilities all point to a relatively consistent chemistry, the Mississippi Valley type deposits present a puzzle of conflicting chemical clues that are impossible to reconcile with any single equilibrium situation. Thus we must

  1. Physical-chemical conditions of ore deposition

    Barton, Paul B.

    Ore deposits form under a wide range of physical and chemical conditions, but those precipitating from hot, aqueous fluids-i.e. the hydrothermal deposits-form generally below 700°C and at pressures of only 1 or 2 kbar or less. Natural aqueous fluids in rocks may extract metal and sulfur from a variety of rock types or may acquire them as a residual heritage from a crystallizing silicate magma. Ore-forming hydrothermal fluids never appear as hot springs (except in deep, submarine situations) because they boil, mix with surface waters, and cool, thereby losing their ore-bearing ability before reaching the surface. Mineral systems function as chemical buffers and indicators just as buffers and indicators function in a chemical laboratory. By reading the record written in the buffer/indicator assemblages of minerals one can reconstruct many aspects of the former chemical environment. By studying the record of changing conditions one may deduce information regarding the processes functioning to create the succession of chemical environments and the ore deposits they represent. The example of the OH vein at Creede, Colorado, shows a pH buffered by the K-feldspar + muscovite + quartz assemblage and the covariation of S 2 and O 2 buffered by the assemblage chlorite + pyrite + quartz. Boiling of the ore fluid led to its oxidation to hematite-bearing assemblages and simultaneously produced an intensely altered, sericitic capping over the vein in response to the condensation of vapors bearing acidic components. The solubility of metals as calculated from experimental and theoretical studies of mineral solubility appears too low by at least one or two powers of ten to explain the mineralization at Creede. In contrast to Creede where the mineral stabilities all point to a relatively consistent chemistry, the Mississippi Valley type deposits present a puzzle of conflicting chemical clues that are impossible to reconcile with any single equilibrium situation. Thus we must

  2. 40 CFR 440.10 - Applicability; description of the iron ore subcategory.


    ... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Iron Ore Subcategory § 440.10 Applicability; description of the iron ore subcategory. The provisions of this subpart A are applicable to discharges from (a) mines operated to obtain iron ore, regardless of the type of ore...


    Juan Enrique Villalva A.


    Full Text Available The objective of this study was to construct an explanatory model of the spot price of iron ore in the international market. For this, the method of multiple linear regressions was used. As a dependent variable, the spot price of iron ore (62% Fe China Tianjin port was taken, between 2010 and 2013. As independents variables were taken seven variables of international iron ore market. The resulting model includes variables: Iron ore inventory in Chinese ports, Baltic Dry Index (BDI, Iron ore exports from Brazil & Australia and Chinese Rebar Steel Price, as explanatory variables of the behavior of the spot price of iron ore in the international market. The model has an adjusted coefficient of determination R2 of 0.90, and was validated by comparing its predictions vs. known values of 2014.

  4. The Russell gold deposit, Carolina Slate Belt, North Carolina

    Klein, T.L.; Cunningham, C.G.; Logan, M.A.V.; Seal, R.R.


    Gold deposits have been mined in the Carolina slate belt from the early 1800s to recent times, with most of the production from large mines in South Carolina. The Russell mine, one of the larger producers in North Carolina, is located in the central Uwharrie Mountains, and produced over 470 kg of gold. Ore grades averaged about 3.4 grams per tonne (g/ t), with higher-grade zones reported. The Russell deposit is interpreted to be a sediment-hosted, gold-rich, base-metal poor, volcanogenic massive sulfide deposit in which gold was remobilized, in part, during Ordovician metamorphism. The ore was deposited syngenetically with laminated siltstones of the late Proterozoic Tillery Formation that have been metamorphosed to a lower greenschist facies. The Tillery Formation regionally overlies subaerial to shallow marine rhyolitic volcanic and volcaniclastic rocks of the Uwharrie Formation and underlies the marine volcanic and sedimentary rocks of the Cid Formation. Recent mapping has shown that a rhyolitic dome near the Russell mine was extruded during the deposition of the lower part of the Tillery Formation, at about the same time as ore deposition. Relict mafic, rock fragments present in the ore zones suggest contemporaneous bimodal (rhyolite-basalt) volcanism. The maximum formation age of the Russell deposit is younger than 558 Ma, which is similar to that of the larger, well known Brewer, Haile, and Ridgeway deposits of South Carolina. Gold was mined from at least six zones that are parallel to the regional metamorphic foliation. These strongly deformed zones consist of northeast-trending folds, high-angle reverse faults, and asymmetric doubly plunging folds overturned to the southeast. The dominant structure at the mine is an asymmetric doubly plunging anticline with the axis trending N 45?? E, probably related to late Ordovician (456 ?? 2 Ma) regional metamorphism and deformation. Two stages of pyrite growth are recognized. Stage 1, primary, spongy pyrite, is

  5. Remnant colloform pyrite at the haile gold deposit, South Carolina: A textural key to genesis

    Foley, N.; Ayuso, R.A.; Seal, R.R.


    Auriferous iron sulfide-bearing deposits of the Carolina slate belt have distinctive mineralogical and textural features-traits that provide a basis to construct models of ore deposition. Our identification of paragenetically early types of pyrite, especially remnant colloform, crustiform, and layered growth textures of pyrite containing electrum and pyrrhotite, establishes unequivocally that gold mineralization was coeval with deposition of host rocks and not solely related to Paleozoic tectonic events. Ore horizons at the Haile deposit, South Carolina, contain many remnants of early pyrite: (1) fine-grained cubic pyrite disseminated along bedding; (2) fine- grained spongy, rounded masses of pyrite that may envelop or drape over pyrite cubes; (3) fragments of botryoidally and crustiform layered pyrite, and (4) pyritic infilling of vesicles and pumice. Detailed mineral chemistry by petrography, microprobe, SEM, and EDS analysis of replaced pumice and colloform structures containing both arsenic compositional banding and electrum points to coeval deposition of gold and the volcanic host rocks and, thus, confirms a syngenetic origin for the gold deposits. Early pyrite textures are present in other major deposits of the Carolina slate belt, such as Ridgeway and Barite Hill, and these provide strong evidence for models whereby the sulfide ores formed prior to tectonism. The role of Paleozoic metamorphism was to remobilize and concentrate gold and other minerals in structurally prepared sites. Recognizing the significance of paragenetically early pyrite and gold textures can play an important role in distinguishing sulfide ores that form in volcanic and sedimentary environments from those formed solely by metamorphic processes. Exploration strategies applied to the Carolina slate belt and correlative rocks in the eastern United States in the Avalonian basement will benefit from using syngenetic models for gold mineralization.

  6. Ore mineralogy of the Serra Pelada Au-Pd-Pt deposit, Carajás, Brazil and implications for ore-forming processes

    Berni, Gabriel V.; Heinrich, Christoph A.; Lobato, Lydia M.; Wall, Vic


    Serra Pelada is a world-class hydrothermal Au-Pd-Pt deposit located at the eastern border of the Amazon craton, northern Brazil. The rocks at Serra Pelada have experienced intense tropical weathering for about 70 Ma, but drill core samples preserve the primary mineralogy and hydrothermal alteration features, with extreme grades of Au, Pd and Pt individually reaching hundreds of parts per million (ppm) by weight. Mineralization at Serra Pelada occurs in hydrothermally altered metasiltstones and dolomitic metasandstones at the hinge zone of a recumbent syncline, comprising zones of hematite, chlorite-carbon, argillic, and siliceous alteration. The main hydrothermal gangue minerals are quartz, kaolinite, sericite, amesite, hematite, monazite, florencite and variable amounts of highly reflective carbonaceous matter. Hydrothermal carbon input is evident from precipitated carbon occurring along crenulation planes and veinlets associated with the precious metals. Ore and accessory minerals include a variety of sulphide, selenide, arsenide, sulphate and oxide minerals, including gold with variable metal contents, palladian gold, fischesserite, sudovikovite, sperrylite, selenian braggite, isomertieite, mertieite-II and secondary Au-Pt-Pd alloys. The composition of fischesserite varies from the ideal formula (Ag3AuSe2) towards a more Ag-rich composition, indicating a disordered solid solution form that is stable only above 260 °C, consistent with the high thermal maturity of associated carbonaceous matter approaching graphite. Primary ore and gangue minerals at Serra Pelada comprise a suite of elements that are best transported in oxidising conditions and precipitated upon reduction. This suggests that fluid mixing between a highly oxidised (metal carrier) and a reduced fluid was a key process for high-grade noble metal precipitation at Serra Pelada.

  7. Metallogeny of the Lannigou Sedimentary Rock-hosted Disseminated Gold Deposit in Southwestern Guizhou Province, China

    BAO Zhiwei; Jayanta GUHA


    The Lannigou deposit is a large-sized sedimentary rock-hosted disseminated gold (SRHDG)deposit located in the Youjiang Basin. It is hosted by the Middle Triassic turbidite. Wall rock alterations, including silicification, pyritization, arsenopyritization, carbonatization and argillization,commonly occur along fractures. PGE study demonstrates that either Permian basalts or Triassic ultrabasic intrusives are unlikely to be the main source of gold mineralization. Coupled with the lack of other magmatic activity in the vicinity of the mining area, an amagmatic origin is proposed. Organic matter compositions and GC-MS analysis of the ores and host rocks show that the organics in the ores and the host rocks have a common source; the organic matter in the ores was mainly indigenous. The positive correlation between S2 and Au contents, along with the common occurrence of organic inclusions, suggest involvement of organic matter in the ore-forming process in terms of promoting Au leaching from the source rocks, making colloidal Au migration possible, as well as hydrocarbon reduction of sulphate. Geological and geochemical characteristics of the Lannigou deposit suggest that it was formed through circulation of meteoric water and probably less importantly organic bearing formation water driven by high geothermal gradient caused by late Yanshanian extension, which leached Au from the source bed, and then migrated as Au-bisulfides and colloidal Au, culminating in deposition by reduction-adsorption and surface complexation of gold onto the growth surface of arsenian pyrite.

  8. Mineralogical Zonation of Wall-Rock Alteration in Jiaodong Gold Province, North China


    Mineralogical zonation of wall-rock alterations in Mesozoic granitoids is summarized from 18 gold deposits in Jiaodong gold province on the Asian mobile continental margin of the west circum-Pacific rim. This paper deals with wall-rock alterations developed around gold mineralizations of the quartz-vein type in granitoids and the wall-rock alteration type in granitoid-basement contacts alongMesozoic fault zones trending mostly NNE-SSW and NE-SW. Five alteration zones are distinguished from host rock to ore zone, namely the chloritization and sericitization zone, the hematitization-rutilization and microclinization zone, the quartz-sericitization zone, the pyrite-quartz-sericitization zone and the pyrite-silicification zone. The former two are outer zones marked by incomplete alteration of first mafic and then felsic minerals of the granitoids, while the later three are inner zones marked by complete alteration of both mafic and felsic minerals of the granitoids leading to retrogressive sericitization and progressive silicification with participation of ore elements. The whole process proceeds under dynamometamorphism with high fugacity of volatiles. Wall-rock alteration is the intermediate link between unaltered host rock and ore mineralization both in time and space. Development of the alteration zonation and its mineral composition controls genetic type of mineralization, size and grade of the deposit and location of the ore zones.

  9. Sulfuric acid leaching of mechanically activated manganese carbonate ore

    Kenan Yıldız


    Full Text Available Acidic leaching of mechanically activated manganese ore from Denizli – Tavas was investigated. The ore was activated mechanically in a planetary mill and the amorphisation in manganese structure was analyzed with X-ray diffraction. The parameters in acidic leaching of the ore were milling time, acid concentration and time. All experiments were performed at 25°C with solid to liquid ratio: 1/10. The activation procedure led to amorphization and structural disordering in manganese ore and accelerated the dissolution of manganese in acidic media.

  10. Tectonomagmatic Metallogenic System of Dexing Ore Field, Jiangxi, China


    13 ore deposits and a large number of ore occurrences cluster in Dexing ore field which is 20 km long and 12 km wide. The tectonic evolution, magmatism, as well as the metallogeny are controlled by the Northeast Jiangxi deep-seated fracture belt (NJDFB). The source is believed to have been derived from the Meso-Neoproterozoic marine volcanism. The magmatic activity of Mesozoic I-type granite could have provided the metal elements, thermal fluid, heat, and the space for ore-forming processes. A unified geological model is proposed, which combines the tectonism, magmatism and metallogeny as the basic control of the giant metal mineralizations.

  11. Pros and Cons,Iron Ore Price Hikes

    Tang Jingtao


    @@ Backaround Baostecl and CVRD reached an agreement on the price hikes of 65 percent and 71 percent in February.And in June Baosteel and Rio Tinto which is the largest iron ore company in Australia reached an agreement on the price hikes of 79.88 percent on the iron ore fines and 96.5 percent on the iron ore lumps.This is the first time that two kinds of the iron ore price grew at the same time in Asian market.

  12. Radon emanation from low-grade uranium ore.

    Sahu, Patitapaban; Mishra, Devi Prasad; Panigrahi, Durga Charan; Jha, Vivekanand; Patnaik, R Lokeswara


    Estimation of radon emanation in uranium mines is given top priority to minimize the risk of inhalation exposure due to short-lived radon progeny. This paper describes the radon emanation studies conducted in the laboratory as well as inside an operating underground uranium mine at Jaduguda, India. Some of the important parameters, such as grade/(226)Ra activity, moisture content, bulk density, porosity and emanation fraction of ore, governing the migration of radon through the ore were determined. Emanation from the ore samples in terms of emanation rate and emanation fraction was measured in the laboratory under airtight condition in glass jar. The in situ radon emanation rate inside the mine was measured from drill holes made in the ore body. The in situ(222)Rn emanation rate from the mine walls varied in the range of 0.22-51.84 × 10(-3) Bq m(-2) s(-1) with the geometric mean of 8.68 × 10(-3) Bq m(-2) s(-1). A significant positive linear correlation (r = 0.99, p 222)Rn emanation rate and the ore grade was observed. The emanation fraction of the ore samples, which varied in the range of 0.004-0.089 with mean value of 0.025 ± 0.02, showed poor correlation with ore grade and porosity. Empirical relationships between radon emanation rate and the ore grade/(226)Ra were also established for quick prediction of radon emanation rate from the ore body.

  13. The Krásná Hora, Milešov, and Příčovy Sb-Au ore deposits, Bohemian Massif: mineralogy, fluid inclusions, and stable isotope constraints on the deposit formation

    Němec, Matěj; Zachariáš, Jiří


    The Krásná Hora-Milešov and Příčovy districts (Czech Republic) are the unique examples of Sb-Au subtype orogenic gold deposits in the Bohemian Massif. They are represented by quartz-stibnite veins and massive stibnite lenses grading into low-grade, disseminated ores in altered host rocks. Gold postdates the stibnite and is often replaced by aurostibite. The ore zones are hosted by hydrothermally altered dikes of lamprophyres (Krásná Hora-Milešov) or are associated with local strike-slip faults (Příčovy). Formation of Sb-Au deposits probably occurred shortly after the main gold-bearing event (348-338 Ma; Au-only deposits) in the central part of the Bohemian Massif. Fluid inclusion analyses suggest that stibnite precipitated at 250 to 130 °C and gold at 200 to 130 °C from low-salinity aqueous fluids. The main quartz gangue hosting the ore precipitated from the same type of fluid at about 300 °C. Early quartz-arsenopyrite veins are not associated with the Sb-Au deposition and formed from low-salinity, aqueous-carbonic fluid at higher pressure and temperature ( 250 MPa, 400 °C). The estimated oxygen isotope composition of the ore-bearing fluid (4 ± 1‰ SMOW; based on post-ore calcite) suggests its metamorphic or mixed magmatic-metamorphic origin and excludes the involvement of meteoric water. Rapid cooling of warm hydrothermal fluids reacting with "cold" host rock was probably the most important factor in the formation of both stibnite and gold.

  14. Signs and symptoms of mercury-exposed gold miners.

    Bose-O'Reilly, Stephan; Bernaudat, Ludovic; Siebert, Uwe; Roider, Gabriele; Nowak, Dennis; Drasch, Gustav


    Gold miners use mercury to extract gold from ore adding liquid mercury to the milled gold-containing ore. This results in a mercury-gold compound, called amalgam. Miners smelt this amalgam to obtain gold, vaporizing it and finally inhaling the toxic mercury fumes. The objective was to merge and analyze data from different projects, to identify typical signs and symptoms of chronic inorganic mercury exposure. Miners and community members from various artisanal small-scale gold mining areas had been examined (Philippines, Mongolia, Tanzania, Zimbabwe, Indonesia). Data of several health assessments were pooled. Urine, blood and hair samples were analyzed for mercury (N = 1252). Questionnaires, standardized medical examinations and neuropsychological tests were used. Participants were grouped into: Controls (N = 209), living in an exposed area (N = 408), working with mercury as panners (N = 181), working with mercury as amalgam burners (N = 454). Chi2 test, linear trend test, Mann-Whitney test, Kruskal-Wallis test, correlation coefficient, Spearman's rho, and analysis of variance tests were used. An algorithm was used to define participants with chronic mercury intoxication. Mean mercury concentrations in all exposed subgroups were elevated and above threshold limits, with amalgam burners showing highest levels. Typical symptoms of chronic metallic mercury intoxication were tremor, ataxia, coordination problems, excessive salivation and metallic taste. Participants from the exposed groups showed poorer results in different neuropsychological tests in comparison to the control group. Fifty-four percent of the high-exposed group (amalgam burners) were diagnosed as being mercury-intoxicated, compared to 0% within the control group (Chi2 p mercury intoxication, with tremor, ataxia and other neurological symptoms together with a raised body burden of mercury was clinically diagnosed in exposed people in artisanal small-scale mining areas. The mercury exposure needs to be

  15. Remobilisation features and structural control on ore grade distribution at the Konkola stratiform Cu-Co ore deposit, Zambia

    Torremans, K.; Gauquie, J.; Boyce, A. J.; Barrie, C.D.; Sikazwe, O.; Muchez, P.H.


    The Konkola deposit is a high grade stratiform Cu–Co ore deposit in the Central African Copperbelt in Zambia. Economic mineralisation is confined to the Ore Shale formation, part of the Neoproterozoic metasedimentary rocks of the Katanga Supergroup. Petrographic study reveals that the copper–cobalt ore minerals are disseminated within the host rock, sometimes concentrated along bedding planes, often associated with dolomitic bands or clustered in cemented lenses and in layer-parallel and irre...

  16. The coupled geochemistry of Au and As in pyrite from hydrothermal ore deposits

    Deditius, Artur P.; Reich, Martin; Kesler, Stephen E.; Utsunomiya, Satoshi; Chryssoulis, Stephen L.; Walshe, John; Ewing, Rodney C.


    The ubiquity of Au-bearing arsenian pyrite in hydrothermal ore deposits suggests that the coupled geochemical behaviour of Au and As in this sulfide occurs under a wide range of physico-chemical conditions. Despite significant advances in the last 20 years, fundamental factors controlling Au and As ratios in pyrite from ore deposits remain poorly known. Here we explore these constraints using new and previously published EMPA, LA-ICP-MS, SIMS, and μ-PIXE analyses of As and Au in pyrite from Carlin-type Au, epithermal Au, porphyry Cu, Cu-Au, and orogenic Au deposits, volcanogenic massive sulfide (VHMS), Witwatersrand Au, iron oxide copper gold (IOCG), and coal deposits. Pyrite included in the data compilation formed under temperatures from ∼30 to ∼600 °C and in a wide variety of geological environments. The pyrite Au-As data form a wedge-shaped zone in compositional space, and the fact that most data points plot below the solid solubility limit defined by Reich et al. (2005) indicate that Au1+ is the dominant form of Au in arsenian pyrite and that Au-bearing ore fluids that deposit this sulfide are mostly undersaturated with respect to native Au. The analytical data also show that the solid solubility limit of Au in arsenian pyrite defined by an Au/As ratio of 0.02 is independent of the geochemical environment of pyrite formation and rather depends on the crystal-chemical properties of pyrite and post-depositional alteration. Compilation of Au-As concentrations and formation temperatures for pyrite indicates that Au and As solubility in pyrite is retrograde; Au and As contents decrease as a function of increasing temperature from ∼200 to ∼500 °C. Based on these results, two major Au-As trends for Au-bearing arsenian pyrite from ore deposits are defined. One trend is formed by pyrites from Carlin-type and orogenic Au deposits where compositions are largely controlled by fluid-rock interactions and/or can be highly perturbed by changes in temperature and

  17. Organic Geochemistry of Sedimentary Rock-hosted Disseminated Gold Deposits in Southwestern Guizhou Province,China

    BAO Zhiwei; ZHAO Zhenhua; Jayanta GUHA


    Sedimentary rock-hosted disseminated gold (SRHDG) deposits in the Youjiang-Nanpanjiang Basin,southwestern Guizhou Province are commonly hosted by the same fold crests that commonly contain a remarkable amount of organic material. The total organic carbon (TOC) contents of the ores and host rocks are usually less than 1%. The reflectance of vitrinite and pyrobitumen in the ores and the host rocks ranges from 1.5% to 4.5%, often in the range of 2% to 3%. In the Lannigou deposit, the reflectance of vitrinite and pyrobitumen in the ores is usually somewhat higher than those within the host rocks, indicating a hydrothermal impact on the organic matter in the altered host rocks. On the contrary, the estimated maximum paleotemperatures of the Getang and Zimudang deposits are higher than the homogenization temperatures of the fluid inclusions in the ores, signifying that the organic matter maturation predated Au mineralization. No correlation between the organic matter contents and Au concentrations were recognized in the ores.However, the most striking observation is that there is a positive correlation between the S2 (a parameter of Rock-Eval analysis), Au and As contents of the ores in the Lannigou deposit. Organic matter maturation and migration is apparent from the TOC vs. HCI diagram. Furthermore, group analysis of the dichloromethane extractable organic component of the ores and host rocks shows that the maturation degree of the organic matter in the ores is slightly higher than that of the host rocks in the Lannigou gold deposit. However, the compositions of their alkanes, steranes and terpenes, which serve as biomarkers, are quite similar; this suggests that the organic matter found in the ores and host rocks has a common marine source. Organic matter probably contributed to the preconcentration of Au in the host rocks. Hydrocarbons in the system,on the other hand, clearly contributed to the emplacement of the gold mineralization through thermal sulfate reduction

  18. Role of ore mineralogy in optimizing conditions for bioleaching low-grade complex sulphide ores



    The role that ore mineralogy plays in understanding and optimizing the conditions favouring the bioleaching of complex sulphide ore containing high amounts of siderite was studied using mixed cultures of mesophilic bacteria, with emphasis on zinc,lead and copper recoveries. The influencing parameters investigated include particle size, stirring speed, volume of inoculum, pulp density, and pH. The results show that the mixed mesophilic cultures can extract about two and a half times the amount of zinc than copper over an equivalent period of time. The highest zinc and copper recoveries of 89.2% and 36.4% respectively are obtained at particle size of 75 μm, stirring speed of 150 r/min, pulp density of 10% (w/v), 12% (v/v) inoculum concentration, and a pH of 1.6. Variations in elemental composition within different particle sizes resulting from the mineralogy of the ore account for the bioleaching behaviour at varying particle sizes. The dissolution at varying pulp density, volume of inoculum, solution pH and the low solution potential observed are also influenced by ore mineralogy.

  19. Puziwan Gold Deposit in Shanxi, China:A Special Linear Cryptoexplosive Breccia Type Gold Deposit


    The Puziwan gold deposit is a special linear cryptoexplosive breccia type deposit found in northeastern Shanxi, China, in recent years. The deposit is located in a secondary metallogenic belt of the most famous Au-Ag polymetallic metallogenic belt along the north margin of the North China platform. The secondary metallogenic belt is a synmagmatic tension-shear fault-fracture belt of ENE linear trend. The Indosinian cryptoexplosive breccia body, quartz monzonitic porphyry (beschtauite breccia), quartz monzonite (243.7 Ma, K-Ar), Yanshanian granite-porphyry (105± 6 Ma, Rb-Sr) and orebodies mostly occur as dykes or veins and short lenses along the structural fracture belt. The orebodies are emplaced in the fractured cryptoexplosive breccia body in the tectonomagmatic belt and their attitude is consistent with that of the breccia body. The orebodies have two types: one is shallow-seated thick and big ones, which are short-lenticular in plan and wedge-shaped in cross section, shallow buried, large in size and high-grade; the other is lean orebodies, which occur as parallel veins at depths. The ores are mainly of Au-Ag polymetallic sulphide-rich breccia type. Pyrite (limonite) is the dominant metallic mineral, with subordinate chalcopyrite, galena, sphalerite, tenantite, native gold, electrum, native silver and argentite. The gangue minerals consist mainly of quartz and plagioclase, with subordinate carbonate minerals, alunite chalcedony and kaolin. Kaolinization is the characteristic alteration type. Sulphide minerals contain abundant trace minerals such as Cu, Pb, Ag, Sb and Hg, while in the ores Ag, Cu, Pb, Zn, As and Sb are the best indicator element assemblage of Au. The δ34S(‰ values of the ores range from - 3.2‰to 5.3‰ with average - 0.102‰ The δOH2O(‰ and δD(‰ values are in the ranges from - 3.1‰to 7.73‰and from - 64‰to - 90‰respectively. The Pb isotopic compositions of the rocks and ores in this region indicate that Pb comes from three

  20. Metallogenesis of superlarge gold deposits in Jiaodong region and deep processes of subcontinental lithosphere beneath North China Craton in Mesozoic

    ZHOU; Xinhua(周新华); YANG; Jinhui(杨进辉); ZHANG; Lianchang(张连昌)


    The study of ore-forming chronology indicates that the superlarge gold deposits in the Jiaodong region were formed in 120±10 Ma. Sr-Nd-Pb isotopic compositions from typical gold deposits suggest that ore-forming materials were derived from the multisources, mantle component was partly involved in mineralization, the deep dynamic processes are the major geological background of large-scale metallogenesis in the Jiaodong region in Mesozoic. The deep pro- cesses mainly include the effect of post deep-subduction of continental crust of the central orogen belt and the distant effect of subduction of the paleo-Pacific plate underneath the Eurasian continent. However, lithosphere thinning, crust-mantle interaction, crustal extension and formation of large-type ore-controlling structures would be the comprehensive consequences of the above- mentioned geodynamic processes in the region.

  1. Bioprocessing of ores: Application to space resources

    Johansson, Karl R.

    The role of microorganisms in the oxidation and leaching of various ores (especially those of copper, iron, and uranium) is well known. This role is increasingly being applied by the mining, metallurgy, and sewage industries in the bioconcentration of metal ions from natural receiving waters and from waste waters. It is concluded that bioprocessing using bacteria in closed reactors may be a variable option for the recovery of metals from the lunar regolith. Obviously, considerable research must be done to define the process, specify the appropriate bacteria, determine the necessary conditions and limitations, and evaluate the overall feasibility.

  2. Project StORe: Social Science report

    Burton, Guy


    There was widespread support across the social science research community regarding the aims of the StORe Project Nearly half of social science respondents claimed that both source-to-output and out-put-to source repositories would offer a ‘significant advantage to my work’; a third in both cases claimed it would be ‘useful but not of major significance’ Postgraduate students were generally more enthusiastic about source-to-output and output-to-source repositories than acade...

  3. Taguchi optimization: Case study of gold recovery from amalgamation tailing by using froth flotation method

    Sudibyo, Aji, B. B.; Sumardi, S.; Mufakir, F. R.; Junaidi, A.; Nurjaman, F.; Karna, Aziza, Aulia


    Gold amalgamation process was widely used to treat gold ore. This process produces the tailing or amalgamation solid waste, which still contains gold at 8-9 ppm. Froth flotation is one of the promising methods to beneficiate gold from this tailing. However, this process requires optimal conditions which depends on the type of raw material. In this study, Taguchi method was used to optimize the optimum conditions of the froth flotation process. The Taguchi optimization shows that the gold recovery was strongly influenced by the particle size which is the best particle size at 150 mesh followed by the Potassium amyl xanthate concentration, pH and pine oil concentration at 1133.98, 4535.92 and 68.04 gr/ton amalgamation tailing, respectively.

  4. Sedimentary exhalative nickel-molybdenum ores in south China

    Lott, D.A.; Coveney, R.M.; Murowchick, J.B.; Grauch, R.I.


    Unique bedded Ni-Mo ores hosted by black shales were discovered in localized paleobasins along the Yangzte platform of southern China in 1971. Textural evidence and radiometric dates imply ore formation during sedimentation of black shales that grade into readily combustible beds, termed stone coals, which contain 10 to 15 percent organic carbon. Studies of 427 fluid inclusions indicate extreme variation in hydrothermal brine salinities that were contained by Proterozoic dolostones underlying the ore zone in Hunan and Guizhou. Variations of fluid inclusion salinities, which range from 0.1 to 21.6 wt percent NaCl equiv, are attributed to differences in the compositions of brines in strata underlying the ore bed, complicated by the presence of seawater and dilute fluids that represent condensates of vapors generated by boiling of mineralizing fluids or Cambrian meteoric water. The complex processes of ore deposition led to scattered homogenization temperatures ranging from 100??to 187??C within the Hunan ore zone and from 65??to 183??C within the Guizhou ore zone. While living organisms probably did not directly accumulate metals in situ in sufficient amounts to explain the unusually high grades of the deposits, sulfur isotope ratios indicate that bacteria, now preserved as abundant microfossils, provided sufficient sulfide for the ores by reduction of seawater sulfate. Such microbiota may have depended on vent fluids and transported organic matter for key nutrients and are consistent with a sedex origin for the ores. Vent fluids interacted with organic remains, including rounded fragments of microbial mats that were likely transported to the site of ore deposition by the action of waves and bottom currents prior to replacement by ore minerals.

  5. Tectonic Dynamic Metallization of Silver-Gold Hydrothermal Fluids in Proterozoic Gneiss Terrene Shear Zones, Suichang, Zhejiang, China


    The Suichang mine is the largest silicified vein-type silver-gold mineralization system in Southeast China, whose ore bodies are controlled by shear zones developing in Lower Proterozoic gneiss terrene with initial migmatization, which is covered by Upper Jurassic and Lower Cretaceous volcanic rock system and cut by acidic igneous veins of Jurassic and Cretaceous. The conclusions are as follows: (1) The ore-forming fluid is defined as superhigh tectonic-metamorphic fluid on the base of: ① δ(D)-δ(18O) values; ② fluid inclusions; ③ trace elements of pyrite from ores. (2) The shear zone silicified orebodies occurred in Proterozoic, Jurassic and Cretaceous, which have been transformed in part by ore-bearing comb quartz vein of volcanism.

  6. Influence of copper minerals on cyanide leaching of gold


    The paper thermodynamically examined the behavior of various copper minerals in cyanide solu-tions and investigated the influence of copper minerals on cyanide leaching of gold. In elucidating the influence of copper minerals on cyanide leaching of gold, copper minerals were classified into two types according to their solubility in cyanide solutions by proposing two concepts, cyaniding easily soluble copper (ECu) and cyaniding insoluble copper. The former involves copper occurrence in metal, oxides and secondary sulfides, and the latter refers mainly to primary sulfides. Experimental results show that not all the total copper in an ore affected cyanide leaching of gold, while cyaniding easily soluble copper turns out to be the decisive factor that interferes with gold cyanidation by causing decrease in gold cyanidation recovery and increase in cyanide consumption. When cyaniding easily soluble copper content (wE(Cu)) lies in the range of 0-0.25%, it linearly affects gold cyanidation recovery (R) as well as cyanide consumption (mc). The regression equations have been worked out to be R(%)=94.177 5-142.735 7 wE(Cu) with a correlation coefficient of -0.902 and mc=5.590 7+33.572 9 wE(Cu) with a correlation coefficient of 0.945, respectively.

  7. Mixed State and High Effective Utilization of Pilbara Blending Iron Ore Powder%Mixed State and High Effective Utilization of Pilbara Blending Iron Ore Powder

    CAO Yong-guo; WU Sheng-li; HAN Hong-liang; WANG Hong-wei; XUE Fang; LIU Xiao-qin


    Pilbara blending iron ore powder (PB powder) is blending ores with good and poor quality iron ores, so how to use PB power effectively is a problem. The self-characteristics of PB powder and its single-components were studied respectively such as the macroscopic properties, microscopic properties, and high-temperature properties the behavior and effect in the sintering were mastered. Then based on the new ore-proportioning idea of iron ores sintering characteristics complementary, the principles on the effective use of PB powder were discussed, and was fur ther validated through the sintering pot test and industrial production. The results show that PB powder is composed of three kinds of iron ore, and the sintering characteristics of different iron ores are obviously discrepant. With the ore-proportioning optimization based on the iron ores sintering characteristics complementary, the proportion of PB iron ore powder can be increased to more than 45 %.

  8. Iron isotope constraints on the mineralization processes of the Sandaowanzi telluride gold deposit, NE China

    Li, Xingxing; Liu, Junlai; Lu, Di; Ren, Shunli; Liu, Zhengyang


    Iron isotopes have been widely applied to interpret the fluid evolution, supergene alteration and the metallogenic material sources of the hydrothermal deposit. It may also have significant potentials on the research of the deposit. The Sandaowanzi telluride gold deposit, located in the Great Hinggan Range metallogenic Belt in NE China, is a large epithermal gold deposit of low-sulphidation type. It has a total reserve of ≥25t of Au and an average of 15 g/t. Gold-bearing quartz veins or gold lodes strike to the NW and dip 50-80°northeastward. Ore bodies, including low-grade ores along margins and high-grade ores in the central parts, principally occur in quartz veins. More than the 95 percent Au budgets are hosted in gold-silver tellurides. A six-stage paragenetic sequence of mineralization is revealed according to the compositions and microstructures of the mineral assemblages. Although sulfide minerals in the bonanza quartz veins are rare, pyrite are widespread in quartz veins and altered host rocks. Meanwhile there are always chalcopyrite veins within bonanza quartz veins. Pyrite Fe isotope compositions from different levels (from +50m to +210m) of the main ore body of the Sandaowanzi gold ore deposit are investigated. There is an overall variation in δ57Fe values from -0.09 to +0.99 (av. 0.33). Among them, twenty three samples from different mining levels give positiveδ57Fe values, with the maximum positive value at the economic bonanza ores (level +130m). Four samples, however, possess negative values, one at level 170m, one at level 130m, and two at level 50m, respectively. The two negative values from the levels 170m and 130m are near the cores of the high grade ore body. The two negative values from the level 50m occur at one end of the lode ore body. The above data set shows that the δ57Fe values are not homogeneous at different levels of the ore body. On the other hand, a general trend for the positive values is that the highest δ57Fe value is

  9. Ion beam analysis of gold jewelry

    Demortier, Guy


    PIXE milliprobe in a nonvacuum assembly has been proven to be a very rapid and accurate method for the elemental analysis of gold jewelry artefacts. Using protons whose energy is lower than 3 MeV, it is possible to obtain, in a few minutes, the actual composition (copper, iron, gold, silver, etc.) of narrow parts of artefacts, without any sampling, even at microscopic level. Most of the studies of our group in this field concern solders on these jewelry items. Narrow regions of gold artefacts have also been studied with a PIXE microprobe. They were then irradiated in vacuum. Nuclear reaction analyses induced by 2 MeV deuterons are also performed to identify the presence of light elements and, particularly O, N and S. Traces of these elements are of primary importance to characterize the origin of the ores used in various workmanships. Interferences of X-ray lines of Au with those of traces of Cu and Zn are solved using a method of selective excitation of X-rays of these elements. Analytical results have been interpreted in order to understand the workmanship of goldsmiths from the Antiquity. Fakes and repairs (or ornaments added to original artefacts) may also be identified. The ancient recipes are improved to give new soldering procedures at low temperature.

  10. Mineralogical analysis of auriferous ores from the El Diamante mine, Colombia

    Bustos Rodriguez, Humberto, E-mail:; Oyola Lozano, Dagoberto; Rojas Martinez, Yebrayl A. [Universidad del Tolima, Departamento de Fisica (Colombia); Perez Alcazar, German A. [Universidad del Valle, Departamento de Fisica (Colombia); Flege, Stefan; Balogh, Adam G. [Darmstadt University of Technology, Institute of Materials Science (Germany); Cabri, Louis J. [Cabri Consulting Inc. (Canada); Tubrett, Michael [Memorial University of Newfoundland (Canada)


    X-ray diffraction (XRD), Moessbauer spectrometry (MS), secondary ions mass spectroscopy (SIMS) and laser-ablation microprobe-inductively coupled plasma-mass spectrometry (LAM-ICP-MS) were used to study mineral samples of Colombian auriferous ores collected from the 'El Diamante' mine, located in the municipality of Guachavez-Narino, in Colombia. The samples were prepared as polished thin sections and polished sections. From XRD data, quartz, sphalerite and pyrite were detected and their respective cell parameters were estimated. From MS analyses, pyrite, arsenopyrite and chalcopyrite were identified; their respective hyperfine parameters and respective texture were deduced. Multiple regions of approximately 200 x 200 {mu}m in each sample were analyzed with SIMS; the occurrence of 'invisible gold' associated mainly with pyrite and secondarily with arsenopyrite could thus be assigned. It was also found that pyrite is of the arsenious type. Spots from 30 to 40 {mu}m in diameter were analyzed with LAM-ICP-MS for pyrite, arsenopyrite and sphalerite; Au is 'homogeneously' distributed inside the structure of the arsenious pyrite and the arsenopyrite (not as inclusions); the chemical composition indicates similarities of this 'invisible gold', forming a solid solution with arsenious pyrite and arsenopyrite. One hundred nineteen and 62 ppm of 'invisible gold' was quantified in 21 spots analyzed on pyrite and in 14 spots on arsenopyrite, respectively.

  11. Photoinitiated gold sol generation in aqueous Triton X-100 and its analytical application for spectrophotometric determination of gold.

    Pal, A


    Gold complex, HAuCl(4) has been transformed into pink-coloured stable gold sol having lambda(max) at 523 nm (in=3.06x10(3)1.mol(-1)cm(-1)) at room temperature in aqueous Triton X-100 (TX-100) upon photoirradiation. It is a very rapid and simple process and the absorbance at 523 nm is a direct measure of gold concentration. Beer's law is obeyed in the range of 0-150 ppm of gold. The relative standard deviation for 22.7 and 90.9 ppm of gold are 2.8 and 2.5% respectively. The 95% confidence limit (ten determinations) for 22.7 ppm of gold is 23.6+/-0.5 ppm. Sandell sensitivity is 6.44x10(-2) mug cm(-2). TX-100 acts both as a reducing agent and a stabilizer here. Statistical parameters, effects of TX-100 concentration, irradiation time and interferents are studied. The method is applicable for ore and synthetic mixture analysis.


    ZHAO Chong-bin; B.E.Hobbs; H.B.Muhlhaus; A.Ord


    @@ Over the past five years,we have been making efforts to develop a practical and predictive tool to explore for giant ore deposits in hydrothermal systems.Towards this goal,a significant progress has been made towards a better understanding of the basic physical and chemical processes behind ore body formation and mineralization in hydrothermal systems.


    ZHAO; Chong-bin; B.E.Hobbs; H.B.Muhlhaus; A.Ord


    Over the past five years,we have been making efforts to develop a practical and predictive tool to explore for giant ore deposits in hydrothermal systems.Towards this goal,a significant progress has been made towards a better understanding of the basic physical and chemical processes behind ore body formation and mineralization in hydrothermal systems.……

  14. Experimental study of ore gabbro liquid immiscibility

    SANG; Zunan; XIA; Bin; ZHOU; Yongsheng; JIN; Zhenmin


    In this paper, the authors present the results of a preliminary experimental study on partial melting of fine-grained gabbro, Panzhihua, Sichuan Province, China. Experiments were conducted under (confining) pressure ranging from 450 to 500 MPa and temperature of 900-1200℃. The results show that the initial melt is distributed along grain boundaries and triple junctions. Liquid immiscibility phenomena are noted in the melt with two compositional different melt phases, i.e. matrix and sphere phases. The matrix phase is relatively rich in Si, Al and K, and is depleted in Mg, Fe, Ca, Na and Ti, whereas the sphere phase shows opposite trends. The calculation of the melt free energy indicates that the liquid immiscibility is governed by the rule of thermodynamics, as the liquid immiscibility would result in the decrease in free energy of the melt system. The field relationships suggest that the liquid immiscibility may have played an important role in the generation of ore magma of Panzhihua V-Ti magnetite ore deposit. This study thus provides experimental constraints on the mechanism of the formation of V-Ti magnetite deposite.

  15. Application of geophysical methods to gold prospecting in Minas de Corrales, Uruguay; Aplicacao de metodos geofisicos a prospeccao de ouro. Teste nas minas de Corrales, Uruguai

    Costa, Antonio Flavio U. [Companhia de Pesquisas de Recursos Minerais (CPRM), Rio de Janeiro, RJ (Brazil); Dias, Rogerio Aguirre; Barcelos, Andre B.B. de [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil)


    Geophysical methods were tested in San Gregorio gold mine, Minas de Corrales, north region of Uruguay. The ores are mainly stockworks, sheeted veinlet zones, ore shoot and disseminated sulfides types, situated in a silicated and carbonated shear zone structure, over granitic mylonites, quartz diorites, quartz-feldspathic breccia, basic rocks and quartz veins. Magnetic and radiometric methods were applied . VLF and EM34-3 detected the high resistivity silicated and carbonated zone and IP detected a weak PFE anomaly associated with pyrite/gold zone. (author)

  16. 胶西北黄埠岭金矿深部及外围找矿前景与找矿方法探讨%Discussion on ore prospects and prospecting methods of deep and peripherals of Huangbuling gold deposit in the northwest of Jiaodong peninsula

    丛培章; 徐国明; 颜倩琼; 杨斌; 阎复传; 王慧


    黄埠岭金矿位于灵北断裂带西南段,其深部及其外围区仍有找矿潜力,找矿远景区包括:Ⅰ号远景区,位于灵北断裂带盛家‐马埠徐家段,发育遥感泥化蚀变和 As‐Sb‐Au‐Ag‐Cu元素组合异常,针对该区覆土厚、露头少的特点,宜采用高精度瞬变电磁法(TEM)和音频大地电磁法(AMT)等物探技术探测灵北断裂带“主断裂”及其上盘次级断裂位置和深部变化情况;Ⅱ号远景区,位于七厘山矿区,鉴于主矿体走向延长较大及上盘遥感泥化蚀变异常和Au‐Ag‐Cu‐As‐Sb元素组合异常的情况,在其深部寻找“第二富集带”可做为一个主要找矿方向,宜选择典型剖面开展音频大地电磁法(AM T法)测量,探测400m以下深度的断裂带及低阻异常分布位置,为钻探工程验证提供依据;Ⅲ号远景区,位于灵北断裂带凤凰庄段。发育Au‐Ag‐Cu‐As‐Sb元素组合异常和金矿化,针对该区露头发育、化探异常清晰的特点,宜采用大比例尺构造与蚀变填图,结合构造地球化学法加密,查明灵北断裂带主带及次级含矿或蚀变断裂的找矿潜力与找矿有利部位。%Located in the southwest section of Lingbei fault zone ,Huangbuling gold deposit has a good potential for prospecting prediction .Prospecting areas includes Section I from Shengjia to Mabuxujia in Lingbei fault zone ,which is characterized by argillic alteration of remote sensing and abnormal combination of elements As‐Sb‐Au‐Ag‐Cu .It has been suggested that geophysical techniques such as TEM and AMT be used in Lingbei fault zone to probe occurrence changes of the “main fault”and its secondary fractures on the hanging wall ,according to the characteristics of the earth cover and the outcrop of the area .Section II is in Qilishan mining area .In view of the great extention of its orebodies and its argillic alteration of remote sensing and

  17. Excited response of granular ores in vibrating field


    The dynamical theory was utilized to probe into the law of the excited response of granular ores generated by the exciting action of exciter and the influence of wave propagation in vibrating field. The exciter with double axes was presented as an example, and the principle of exciter and its mathematical expression of the excitation force were given. The granular ores have viscidity and damping speciality, on the basis of which the motion equation of excited response of ores was established and the approximate expression of mode-displacement by harmonic excitation and the steady effect solution of coordinate response were deduced. Utilizing the step-by-step integration method, the recursion relation matrix of displacement, velocity and acceleration of the excited response of ores were obtained, and the computational flow chart and a computational example were given. The results show that the excited response can change the dynamical character and the flowing characteristic of granular ores.

  18. Geochemical Characteristics of Jinwozi Gold Deposit,Xinjiang

    章振根; 陈南生


    The Jinwozi gold deposit consists of gold-bearing quartz veins in a biotite granodiorite of Hercynian age (Zircon U-Pb age≈335.7Ma).Ore mineralogy is simple .In addition to native gold,there are only small amounts of sulfides,meinly pyrite and minor sphalerite,chalcopyrite and galena.δ34S val-ues average 6.69‰,and δ18O13.99‰.Abundant CO2 is contained in fluid inclusions from quartz.Homogenization temperatures of fluid inclusions are between 186 and 262°.REE distribution pat-terns indicate that the igneous mass may have been derived from a common initial material of calcareous-argillaceous sediments and alkali basalts as the country rocks.In other words,the Jinwozi granodiorite is of remelting origin from crustal material.Isotopic evidence of S,O and Pb shows that the ore-forming material is genetically related to magmatic hydrothermal activity.

  19. Biodiversity and interactions of acidophiles: Key to understanding and optimizing microbial processing of ores and concentrates



    Mining companies have become increasingly aware of the potential of microbiological approaches for recovering base and precious metals from low-grade ores,and for remediating acidic,metal-rich wastewaters that drain from both operating and abandoned mine sites.Biological systems offer a number of environmental and (sometimes) economical advantages over conventional approaches,such as pyrometallurgy,though their application is not appropriate in every situation.Mineral processing using micro-organisms has been exploited for extracting gold,copper,uranium and cobalt,and current developments are targeting other base metals.Recently,there has been a great increase in our knowledge and understanding of both the diversity of the microbiology of biomining environments,and of how the microorganisms interact with each other.The results from laboratory experiments which have simulated both stirred tank and heap bioreactor systems have shown that microbial consortia are more robust than pure cultures of mineral-oxidizing acidophiles,and also tend to be more effective at bioleaching and bio-oxidizing ores and concentrates.The paper presented a concise review of the nature and interactions of microbial consortia that are involved in the oxidation of sulfide minerals,and how these might be adapted to meet future challenges in biomining operations.

  20. High-temperature performance prediction of iron ore fines and the ore-blending programming problem in sintering

    Bing-ji Yan; Jian-liang Zhang; Hong-wei Guo; Ling-kun Chen; Wei Li


    The high-temperature performance of iron ore fines is an important factor in optimizing ore blending in sintering. However, the application of linear regression analysis and the linear combination method in most other studies always leads to a large deviation from the desired results. In this study, the fuzzy membership functions of the assimilation ability temperature and the liquid fluidity were proposed based on the fuzzy mathematics theory to construct a model for predicting the high-temperature performance of mixed iron ore. Comparisons of the prediction model and experimental results were presented. The results illustrate that the prediction model is more accurate and effec-tive than previously developed models. In addition, fuzzy constraints for the high-temperature performance of iron ore in this research make the results of ore blending more comparable. A solution for the quantitative calculation as well as the programming of fuzzy constraints is also introduced.

  1. Summary of the mineralogy of the Colorado Plateau uranium ores

    Weeks, Alice D.; Coleman, Robert Griffin; Thompson, Mary E.


    In the Colorado Plateau uranium has been produced chiefly from very shallow mines in carnotite ores (oxidized vanadiferous uranium ores) until recent deeper mining penetrated black unoxidized ores in water-saturated rocks and extensive exploration has discovered many deposits of low to nonvanadiferous ores. The uranium ores include a wide range from highly vanadiferous and from as much as one percent to a trace of copper, and contain a small amount of iron and traces of lead, zinc, molybdenum, cobalt, nickel, silver, manganese, and other metals. Recent investigation indicates that the carnotite ores have been derived by progressive oxidation of primary (unoxidized) black ores that contain low-valent uranium and vanadium oxides and silicates. The uranium minerals, uraninite and coffinite, are associated with coalified wood or other carbonaceous material. The vanadium minerals, chiefly montroseite, roscoelite, and other vanadium silicates, occur in the interstices of the sandstone and in siltstone and clay pellets as well as associated with fossil wood. Calcite, dolomite, barite and minor amounts of sulfides, arsenides, and selenides occur in the unoxidized ore. Partially oxidized vanadiferous ore is blue black, purplish brown, or greenish black in contrast to the black or dark gray unoxidized ore. Vanadium combines with uranium to form rauvite. The excess vanadium is present in corvusite, fernandinite, melanovanadite and many other quadrivalent and quinquevalent vanadium minerals as well as in vanadium silicates. Pyrite and part or all of the calcite are replaced by iron oxides and gypsum. In oxidized vanadiferous uranium ores the uranium is fixed in the relatively insoluble minerals carnotite and tyuyamunite, and the excess vanadium commonly combines with one or more of the following: calcium, sodium, potassium, magnesium, aluminum, iron, copper, manganese, or barium, or rarely it forms the hydrated pentoxide. The relatively stable vanadium silicates are little

  2. Stable Te isotope fractionation in tellurium-bearing minerals from precious metal hydrothermal ore deposits

    Fornadel, Andrew P.; Spry, Paul G.; Haghnegahdar, Mojhgan A.; Schauble, Edwin A.; Jackson, Simon E.; Mills, Stuart J.


    The tellurium isotope compositions of naturally-occurring tellurides, native tellurium, and tellurites were measured by multicollector-inductively coupled plasma-mass spectrometry (MC-ICP-MS) and compared to theoretical values for equilibrium mass-dependent isotopic fractionation of representative Te-bearing species estimated with first-principles thermodynamic calculations. Calculated fractionation models suggest that 130/125Te fractionations as large as 4‰ occur at 100 °C between coexisting tellurates (Te VI) and tellurides (Te -II) or or native tellurium Te(0), and smaller, typically secondary emmonsite, δ130/125Te compositions were identical. The coincidence of δ130/125Te between all oxidized and reduced species in this study and the apparent lack of isotopic fractionation between native tellurium and emmonsite in one sample suggest that oxidation processes cause little to no fractionation. Because Te is predominantly transported as an oxidized aqueous phase or as a reduced vapor phase under hydrothermal conditions, either a reduction of oxidized Te in hydrothermal liquids or deposition of Te from a reduced vapor to a solid is necessary to form the common tellurides and native tellurium in ore-forming systems. Our data suggest that these sorts of reactions during mineralization may account for a ∼3‰ range of δ130/125Te values. Based on the data ranges for Te minerals from various ore deposits, the underpinning geologic processes responsible for mineralization seem to have primary control on the magnitude of fractionation, with tellurides in epithermal gold deposits showing a narrower range of isotope values than those in orogenic gold and volcanogenic massive sulfide deposits.

  3. Grade-Tonnage, Ore Value-Tonnage, and Enrichment Ratio-Tonnage Models for Resource Assessment


    According to grade-tonnage diagrams of nickel and zinc deposits, their critical grades are 0.4 % and 3.4 %, respectively, and hence the former resources can be considered optimistic and the latter pessimistic. The grade-tonnage diagram of gold deposits is convex downwards suggesting that the critical grade is 1×10-6 in the low-grade part. The ore value (OV)-tonnage diagram of all deposits in the world consists of three parts: high, middle and low value classes. The enrichment ratio (ER)-tonnage diagram of all deposits in the world also consists of three parts: high, middle and low ratio classes. Nine quality categories defined by ER and OV are characterized by some keywords indicating deposit types as follows: category HH (high ER-high OV: 0.7 %) by “unconformity” and “Mississippi Valley”, category HM (high ER-middle OV: 0.7 %) by “vein”, category ML (middle ER-low OV: 0 %) by “sandstone”, “stockwork” and “dissemination”, category LM by “orthomagmatic”, “laterite”, komatiite“ and ”chemical“, and category LL by “porphyry”, “dissemination” and “placer”. Category MM is not characterized by any keyword. If the commodities of a deposit are defined by both the enrichment ratio and the ore value, the defined commodities are relatively coincident for gold and nickel, but different for copper, silver and zinc, and greatly different for molybdenum and lead. Deposits containing lead and/or zinc are complimentary. If the commodity Pb+Zn is applied, most lead or zinc deposits are classified as Pb+Zn by both definitions. Accessory metals are commonly expected for deposits of kuroko-type zinc, epithermal silver, massive sulfide-type zinc and volcanogenic zinc, but uncommon for deposits of orthomagmatic chromium, chemically precipitated copper and sandstone-type uranium.

  4. Research and Application of Flotation Column in Domestic Metallic Ore Beneficiation%浮选柱在国内金属矿选矿中的研究及应用

    吕晋芳; 童雄


    浮选柱凭着其结构简单、占地面积小、技术指标好等优点,在国外得到了广泛的应用,而目前国内主要用于煤的浮选,在金属行业中的应用较少.本文介绍了浮选柱在选别国内铜矿、铅锌矿、金矿、铁矿、镍矿、钼矿及其尾矿中的研究及取得的良好效果,指出了浮选柱在国内金属矿选矿中有着广阔的市场前景.%Flotation column with its advantages of simple structure, small occupation area and good technical inde xes is widely used at abroad, while it is mainly used for coal flotation at home, less in the metallic field. This paper introduced the research and the achieved good results that flotation column was used for separating copper ore,lead -zinc ore, gold ore, iron ore, nickel ore, molybdenum ore and tailings. At the same time, the market prospect of the flotation column was also pointed.

  5. Mineralogical and geochemical features of the Oleninskoe gold occurrence (Kola region, Russia)

    Galkin, N.; Gavrilenko, B.


    The Oleninskoe gold occurrence is situated within the Archean Kolmozero-Voron’ja suture structure. The host rocks are basalts and gabbro-diabases metamorphosed in the amphibolite facies. The mineralized zone is bordered in the west by a major fault intersecting the entire structure. The thickness of the zone is approximately 50 m, it strikes over 1.5 km, and dips to at least 100 m. The alteration processes in the rocks of the Oleninskoe occurrence are represented mainly by the silicification (thin quartz veinlet), biotitization, epidotization, diopsidization etc. Based on study of fissure systems in the host rocks, it is established that ore bodies tend to an intersection of disjunctive dislocations of the lower order represented by steep longitudinal and transversal fissures. Pyrrhotite-arsenopyrite mineralization of the Oleninskoe gold occurrence is of the streaky-disseminated type. It can be referred to low-sulfide gold-quartz formation. The major ore minerals are pyrrhotite, arsenopyrite, native gold, electrum, native silver, chalcopyrite, blende, galena and silver sulphosalts. The primary gold-bearing mineral is arsenopyrite, in which early gold is emulsive. The size of gold grains varies from 0.001 mm up to 0.2 mm. Later gold is represented by veinlets in sulphides and silicates being 0.1 up to 0.5 mm in size. On the basis of 100 individual geochemical analyses, primary geochemical aureoles of Au, Ag and As were mapped. That allowed to reveal a pod-like shape and orientation of the ore bodies. The orientation of the ore bodies coincides spatially with crystallization and metamorphic schistosity of host rocks and corresponds to the general direct strike of the Archean Kolmozero-Voron’ja structure. It is noted according to the primary aureoles that the rocks with highest concentration of Au, Ag and As tend to the contact of gabbro-diabases and muscovite-quartz metasomatic rocks. The gold composition in the Archean Kolmozero-Voron’ja structure ranges from

  6. Anomalous concentrations of gold, silver, and other metals in the Mill Canyon area, Cortez quadrangle, Eureka and Lander Counties, Nevada

    Elliott, James E.; Wells, John David


    The Mill Canyon area is in the eastern part of the Cortez window of the Roberts Mountains thrust belt in the Cortez quadrangle, north-central Nevada. Gold and silver ores have been mined from fissure veins in Jurassic quartz monzonite and in the bordering Wenban Limestone of Devonian age. Geochemical data show anomalies of gold, silver, lead, zinc, copper, arsenic, antimony, mercury, and tellurium. Geologic and geochemical studies indicate that a formation favorable for gold deposition, the Roberts Mountains Limestone of Silurian age, may be found at depth near the mouth of Mill Canyon.

  7. Cohesive strength of iron ore granules

    Contreras Rafael Jaimes


    Full Text Available We present an experimental and numerical investigation of the mechanical strength of crude iron ore (Hematite granules in which capillary bonds between primary particles are the source of internal cohesion. The strength is measured by subjecting the granules to vertical compression between two plates. We show that the behavior of the granules is ductile with a well-defined plastic threshold which increases with the amount of water. It is found that the compressive strength scales with capillary cohesion with a pre-factor that is nearly independent of size polydispersity for the investigated range of parameters but increases with friction coefficient between primary particles. This weak dependence may be attributed to the class of fine particles which, due to their large number, behaves as a cohesive matrix that controls the strength of the granule.

  8. Cohesive strength of iron ore granules

    Contreras, Rafael Jaimes; Berger, Nicolas; Izard, Edouard; Douce, Jean-François; Koltsov, Alexey; Delenne, Jean-Yves; Azema, Emilien; Nezamabadi, Saeid; van Loo, Frédéric; Pellenq, Roland; Radjai, Farhang


    We present an experimental and numerical investigation of the mechanical strength of crude iron ore (Hematite) granules in which capillary bonds between primary particles are the source of internal cohesion. The strength is measured by subjecting the granules to vertical compression between two plates. We show that the behavior of the granules is ductile with a well-defined plastic threshold which increases with the amount of water. It is found that the compressive strength scales with capillary cohesion with a pre-factor that is nearly independent of size polydispersity for the investigated range of parameters but increases with friction coefficient between primary particles. This weak dependence may be attributed to the class of fine particles which, due to their large number, behaves as a cohesive matrix that controls the strength of the granule.

  9. Exact linear modeling using Ore algebras

    Schindelar, Kristina; Zerz, Eva


    Linear exact modeling is a problem coming from system identification: Given a set of observed trajectories, the goal is find a model (usually, a system of partial differential and/or difference equations) that explains the data as precisely as possible. The case of operators with constant coefficients is well studied and known in the systems theoretic literature, whereas the operators with varying coefficients were addressed only recently. This question can be tackled either using Gr\\"obner bases for modules over Ore algebras or by following the ideas from differential algebra and computing in commutative rings. In this paper, we present algorithmic methods to compute "most powerful unfalsified models" (MPUM) and their counterparts with variable coefficients (VMPUM) for polynomial and polynomial-exponential signals. We also study the structural properties of the resulting models, discuss computer algebraic techniques behind algorithms and provide several examples.

  10. Improved polynomial remainder sequences for Ore polynomials.

    Jaroschek, Maximilian


    Polynomial remainder sequences contain the intermediate results of the Euclidean algorithm when applied to (non-)commutative polynomials. The running time of the algorithm is dependent on the size of the coefficients of the remainders. Different ways have been studied to make these as small as possible. The subresultant sequence of two polynomials is a polynomial remainder sequence in which the size of the coefficients is optimal in the generic case, but when taking the input from applications, the coefficients are often larger than necessary. We generalize two improvements of the subresultant sequence to Ore polynomials and derive a new bound for the minimal coefficient size. Our approach also yields a new proof for the results in the commutative case, providing a new point of view on the origin of the extraneous factors of the coefficients.

  11. Rigid Ideals and Radicals of Ore Extensions

    Chan Yong Hong; Tai Keun Kwak; S. Tariq Rizvi


    For an endomorphism σ of a ring R, Krempa called σ a rigid endomorphism if aσ(a) = 0 implies a= 0 for a ∈ R. A ring R is called rigid if there exists a rigid endomorphism of R. In this paper, we extend the σ-rigid property of a ring R to an ideal of R. For a σ-ideal Ⅰ of a ring R, we call Ⅰ a σ-rigid ideal if aσ(a) ∈Ⅰ implies a ∈Ⅰ for a ∈ R. We characterize σ-rigid ideals and study related properties. The connections of the prime radical and the upper nil radical of R with the prime radical and the upper nil radical of the Ore extension R[x; σ, δ], respectively, are also investigated.

  12. Research Progress of the Arsenic-containing Refractory Gold Flotation%含砷难处理金矿浮选研究进展

    沈述保; 唐明刚


    随着易处理单一金矿储量不断减少,含砷难处理金矿所占比重越来越大。此类矿石普遍采用浮选法处理,总结含砷难处理矿石浮选技术研究进展有重要意义。浮选药剂的研发是含砷金矿分选技术的重点,近年来高选择性捕收剂和砷抑制剂的研发和应用取得了较多进展,浮选工艺研究也取得了创新性成果,而新型捕收剂及砷抑制剂的研究应用和浮选联合工艺开发是未来含砷难处理金矿研究的主要方向。%With the increasingly exhausting of easily leachable gold ores,the proportion of refractory gold ores which containing arsenic is growing larger.The ores were dealt commonly with the flotation method,and summarizing the flotation technology of refractory gold ores which containing arsenic is very important. Obviously,research and development of the flotation reagent is the key to the flotation technology of the containing arsenic gold ores.In recent years,it has made more progress for the development and application of the high selective collector and arsenic inhibitors.And the research on flotation also has made innovative achievements.In short,the development and application of the high selective collector and arsenic inhibitors and the exploitations of combined processes are the main directions for the research of refractory gold ores which containing arsenic.

  13. Super-Enrichment of Dispersed Elements and Associated Ore Deposits

    高振敏; 姚林波


    Dispersed elements do not always occur as associated elements in the ore deposits of other elements. Instead, they can constitute independent ore deposits. The focus of this paper is placed on the mechanism of super-enrichment of the four dispersed elements TI, Ge, Se, and Te under favorable geological conditions, where their enrichment coefficients are so high that their abundances can reach n×103-n×104, sometimes even up to n×106 times (e. g. Te) those of the crust. As a result, they can form their independent ore deposits. Studies have shown that such independent ore deposits are mostly distributed in the southwestern part of China, most of which belong to low-temperature ore deposits, ranging in age from Yanshanian to Himalayan(Cretaceous to Cenozoic), with a significant time gap with the host strata. Moreover, this paper also deals with the existing forms (as independent minerals, occurring isomorphously and being adsorbed) of the dispersed elements in those independent ore deposits. The discovery of independent ore deposits of dispersed elements is a great breakthrough in the study of dispersed element metallogenesis.

  14. Leaching hydrodynamics of weathered elution-deposited rare earth ore


    Both porosity (φ) and permeability (k) of the weathered elution-deposited rare earth ores are basic hydrodynamic parameters for RE leaching. The relationship between k and φ of two typical rare earth ores of South China in the packed bed was investigated by measuring the flow (Q) under various leaching pressure difference (Δp). The experimental results show that the relationship between k and φ is unique, moreover the relationship between Q and Δp is in accord with the Darcy's law. The effects of the type of ores, the leaching reagents and its concentration, the granule ore size on the leaching permeability have also been investigated. It is demonstrated that kH (for heavy RE ore, kH=35.98 mm2)>kM-H (for middle-heavy RE ore,kM-H=28.50 mm2), whereas k(NH4NO3)>k(NH4Cl)>k[(NH4)2SO4], and the k value increases with increasing leaching reagents concentration and granule ore size(k0.60~0.75 mm=99.96 mm2,k0.125~0.60 mm=11.83 mm2, k0.074~0.125 mm=0.84 mm2).

  15. Direct Biohydrometallurgical Extraction of Iron from Ore

    T.C. Eisele


    A completely novel approach to iron extraction was investigated, based on reductive leaching of iron by anaerobic bacteria. Microorganisms were collected from an anaerobic bog where natural seepage of dissolved iron was observed. This mixed culture was used to reduce insoluble iron in a magnetite ore to the soluble ferrous (Fe{sup +2}) state. While dissolution rates were slow, concentrations of dissolved iron as high as 3487 mg/l could be reached if sufficient time was allowed. A factorial study of the effects of trace nutrients and different forms of organic matter indicated that the best dissolution rates and highest dissolved iron concentrations were achieved using soluble carbohydrate (sucrose) as the bacterial food source, and that nutrients other than nitrogen, phosphorus, potassium, sodium, and acetate were not necessary. A key factor in reaching high levels of dissolved iron was maintaining a high level of carbon dioxide in solution, since the solubility of iron carbonates increases markedly as the quantity of dissolved carbon dioxide increases. Once the iron is dissolved, it has been demonstrated that the ferrous iron can then be electroplated from solution, provided that the concentration of iron is sufficiently high and the hydrogen ion concentration is sufficiently low. However, if the leaching solution is electrolyzed directly, organic matter precipitates at the cathode along with the metallic iron. To prevent this problem, the ferrous iron should be separated from the bulk solution in a more concentrated, purified form. One route to accomplishing this is to take advantage of the change in solubility of ferrous iron as a function of carbon dioxide concentration. By cycling the concentration of carbon dioxide in solution, it is possible to produce an iron-rich concentrate that should be suitable for electrolysis. This represents the first viable hydrometallurgical method for leaching iron directly from ore and producing metallic iron.

  16. Environmental monitoring at the Nalunaq Gold Mine, South Greenland, 2004

    Glahder, C. M.; Asmund, G.

    Monitoring was performed in the Nalunaq Gold Mine area, Nanortalik mu-nicipality, South Greenland during 20-26 August 2004. This was eight months after the first shipment of ore. Samples were collected at four marine stations in the Kirkespir Bay, Arctic char were sampled in the Kirkespir River......, and li-chens were collected at 20 stations in the Kirkespir Valley. Samples were analysed for 10 elements with an ICP-MS. Concentrations of Zn, Cu, Cr, As and Co were elevated 3-9 times compared to background concentrations found prior to mine start. The increased level of contamination in the local area...

  17. Sulfur isotope geochemistry of ore and gangue minerals from the Silesian-Cracow Mississippi Valley-type ore district, Poland

    Leach, D.L.; Vets, J.G.; Gent, C.A.


    Studies of the sulfur isotopic composition of ore and gangue minerals from the Silesian-Cracow Zn-Pb district were conducted to gain insights into processes that controlled the location and distribution of the ore deposits. Results of this study show that minerals from the Silesian-Cracow ore district have the largest range of sulfur isotope compositions in sulfides observed from any Mississippi Valley-type ore district in the world. The ??34S values for sulfide minerals range from +38 to -32 per mil for the entire paragenetic sequence but individual stages exhibit smaller ranges. There is a well developed correlation between the sulfur isotope composition and paragenetic stage of ore deposition. The first important ore stage contains mostly positive ??34S values, around 5 per mil. The second stage of ore formation are lower, with a median value of around -5 to -15 per mil, and with some values as low as -32 per mil. Late stage barite contains isotopically heavy sulfur around +32 per mil. The range in sulfur isotope compositions can be explained by contributions of sulfur from a variety of source rocks together with sulfur isotope fractionations produced by the reaction paths for sulfate reduction. Much of the variation in sulfur isotope compositions can be explained by bacterial reduction of sedimentary sulfate and disequilibrium reactions by intermediate-valency sulfur species, especially in the late-stage pyrite and sphalerite. Organic reduction of sulfate and thermal release of sulfur from coals in the Upper Silesian Coal Basin may have been important contributors to sulfur in the ore minerals. The sulfur isotopic data, ore mineral textures, and fluid inclusion data, are consistent with the hypothesis that fluid mixing was the dominant ore forming mechanism. The rather distinct lowering of ?? 34S values in sulfides from stage 2 to stage 3 is believed to reflect some fundamental change in the source of reduced sulfur and/or hydrology of the ore

  18. Water leaching of titanium from ore flotation residue.

    Jaworska, Malgorzata M; Guibal, Eric


    Copper ore tailings were tested for the stability of titanium submitted to water leaching in three different reactor systems (agitated vessel, bioreactor and percolated fixed-bed column). For each of these systems, titanium extraction did not exceed 1% of the available metal. Biomass removed from ore residue adsorbed a small part of the titanium with sorption capacities below 20-30 mg g(-1), but most of this biomass was sequestered in the ore residue. Oxygen and carbon dioxide concentrations were monitored and changes in concentration correlated with bacteria development at the initial stage of the process and to fungal development in the latter stages.

  19. Microstructure of Bentonite in Iron Ore Green Pellets

    Bhuiyan, Iftekhar U.; Mouzon, Johanne; Schröppel, Birgit; Kaech, Andres; Dobryden, Illia; Forsmo, Seija P.E.; Hedlund, Jonas


    Sodium-activated calcium bentonite is used as a binder in iron ore pellets and is known to increase strength of both wet and dry iron ore green pellets. In this article, the microstructure of bentonite in magnetite pellets is revealed for the first time using scanning electron microscopy. The microstructure of bentonite in wet and dry iron ore pellets, as well as in distilled water, was imaged by various imaging techniques (e.g., imaging at low voltage with monochromatic and decelerated beam ...

  20. Biological-Chemical Oxidation of Ore Minerals at Pezinok Deposit

    Martin Chovan


    Full Text Available The article presents results of leaching experiments of the comparison between chemical and biological-chemical leaching, at the same conditions in solution, of ores from the Sb-(Au- base metal deposit Pezinok (Malé Karpaty Mts., Western Carpathians, Slovakia. The research study shows the oxidation order and the progression of present ore minerals (löllingite, arsenopyrite, stibnite, native Sb, gudmundite, berthierite, pyrite, sphalerite and chalcopyrite. There are discussed differences between chemical and biological-chemical leaching activity of various ore minerals at the surface of polished sections. The extent of the leaching of sulphide minerals is significantly higher than that without bacteria.

  1. Tourmaline as a recorder of ore-forming processes

    Slack, J.F.; Trumbull, R.B.


    Tourmaline occurs in diverse types of hydrothermal mineral deposits and can be used to constrain the nature and evolution of ore-forming fl uids. Because of its broad range in composition and retention of chemical and isotopic signatures, tourmaline may be the only robust recorder of original mineralizing processes in some deposits. Microtextures and in situ analysis of compositional and isotopic variations in ore-related tourmaline provide valuable insights into hydrothermal systems in seafl oor, sedimentary, magmatic, and metamorphic environments. Deciphering the hydrothermal record in tourmaline also holds promise for aiding exploration programs in the search for new ore deposits.

  2. Start of exploration and mining of uranium ores in Hungary

    Mikolay, I.; Szomolanyi, G. (Mecseki Ercbanyaszati Vallalat, Pecs II (Hungary))


    The mining of uranium ores is the youngest branch in the history of the Hungarian ore mining. The exploration for uranium ores started in Hungary in the decade from 1947, using simple methods at the beginning to apply more developed technologies later on. From the year 1952 Soviet geologists and geophysicists joined the explorations using the most advanced instruments, in co-operation with the Hungarian experts. From 1953 explorations and developments have been concentrated on the SW area of Mountain Mecsek so that by 1957 the preliminary conditions of a successful Hungarian uranium mining were established.

  3. 40 CFR 440.90 - Applicability; description of the antimony ore subcategory.


    ... antimony ore subcategory. 440.90 Section 440.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Antimony Ore Subcategory § 440.90 Applicability; description of the antimony ore subcategory. The provisions of...

  4. 40 CFR 440.20 - Applicability; description of the aluminum ore subcategory.


    ... aluminum ore subcategory. 440.20 Section 440.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Aluminum Ore Subcategory § 440.20 Applicability; description of the aluminum ore subcategory. The provisions of...

  5. 40 CFR 440.50 - Applicability; description of the titanium ore subcategory.


    ... titanium ore subcategory. 440.50 Section 440.50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Titanium Ore Subcategory § 440.50 Applicability; description of the titanium ore subcategory. The provisions of...

  6. 40 CFR 440.70 - Applicability; description of the nickel ore subcategory.


    ... nickel ore subcategory. 440.70 Section 440.70 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Nickel Ore Subcategory § 440.70 Applicability; description of the nickel ore subcategory. The provisions of this...

  7. 40 CFR 440.40 - Applicability; description of the mercury ore subcategory.


    ... mercury ore subcategory. 440.40 Section 440.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Mercury Ore Subcategory § 440.40 Applicability; description of the mercury ore subcategory. The provisions of subpart...

  8. 40 CFR 440.110 - Applicability; description of the platinum ore subcategory.


    ... platinum ore subcategory. 440.110 Section 440.110 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Platinum Ores Subcategory § 440.110 Applicability; description of the platinum ore subcategory. The provisions of...

  9. 40 CFR 440.60 - Applicability; description of the tungsten ore subcategory.


    ... tungsten ore subcategory. 440.60 Section 440.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Tungsten Ore Subcategory § 440.60 Applicability; description of the tungsten ore subcategory. The provisions of...

  10. Gold deposits and occurrences of the Greater Caucasus, Georgia Republic: Their genesis and prospecting criteria

    Kekelia, S.A.; Kekelia, M.A.; Kuloshvili, S.I.; Sadradze, N.G.; Gagnidze, N.E.; Yaroshevich, V.Z.; Asatiani, G.G.; Doebrich, J.L.; Goldfarb, R.J.; Marsh, E.E.


    The south-central part of the Greater Caucasus region, Georgia Republic, represents an extremely prospective region for significant orogenic gold deposits. Gold-bearing quartz veins are concentrated in two extensive WNW-trending belts, the Mestia-Racha and Svaneti districts, within the northern margin of the Southern Slope Zone of the Great Caucasus orogen. This metalliferous region is dominated by Early to Middle Jurassic slates, which are part of a terrane that likely accreted to the continental margin from late Paleozoic to Jurassic. The slates were subsequently intruded by both Middle to Late Jurassic and Neogene granitoids. Quartz veins in the more carbonaceous slate units are most consistently enriched in As, Au, Hg, Sb, and W, and show mineralization styles most consistent with typical orogenic gold deposits. Quartz veins in the Mestia-Racha district were mined in Soviet times for As, Sb, and W, but many of these are now being recognized as gold resource targets. The veins occur in the footwall of a thrust fault between the Southern Slope zone and an earlier accreted terrane, the Main Zone, to the north. Many veins in the district continue along strike for > 1??km and some cut Neogene intrusions, constraining ore formation to the most recent 4 to 5??million years. Gold deposition thus correlates with final collision of the Arabian plate to the south and uplift of the ore-hosting Greater Caucasus. The Zopkhito deposit, previously mined for antimony, contains an estimated 55??t Au at a cutoff grade of 0.5??g/t. The veins are localized in an area where smaller-order structures show a major change in strike from N-S to more E-W trends. A pyrite-arsenopyrite ore stage includes gold concentrated in both sulfide phases; it is overprinted by a later stibnite-dominant stage. Fluid-inclusion studies of ore samples from the Zopkhito deposit indicate minimum trapping temperatures of 300 to 350????C and 200 to 300????C for the two stages, respectively, and minimum

  11. Processes of ore genesis at the world-class Yuchiling molybdenum deposit, Henan province, China

    Zhang, Juan; Ye, Hui-shou; Zhou, Ke; Meng, Fang


    The Yuchiling molybdenum deposit is one of the most significant porphyry molybdenum systems in the eastern Qinling of central China. The mineralization is mainly hosted by a porphyritic granite and associated cryptoexplosive breccia. Hydrothermal alteration minerals include K-feldspar, sericite, pyrite, chlorite, epidote, carbonate, kaolinite, fluorite, and gypsum. Ore minerals are dominated by molybdenite and pyrite, with lesser amounts of chalcopyrite, galena, scheelite, wolframite, ilmenite, leucoxene, native gold, sphalerite, and hematite. The δ34S compositions of sulfide minerals range from -6.0‰ to +4.0‰. The deposit is characterized by four hydrothermal stages: quartz-K-feldspar (stage I), molybdenite-quartz (stage II), pyrite-sericite-quartz (stage III), and quartz-carbonate (stage IV). Microthermometric studies of fluid inclusions show that the fluids evolved gradually during the ore-forming process. Homogenization temperatures, salinities, and minimum pressure estimates for the inclusions from each mineralization stage evolved as follows: (1) stage I: homogenization temperatures = 203.7-525.8 °C, salinities = 2.96-10.49 and 29.66 wt.% NaCl equiv., and minimum pressures = 101.9-196.2 MPa; (2) stage II: homogenization temperatures = 173.6-448.6 °C, salinities = 1.81-9.74 wt.% NaCl equiv., and minimum pressures = 93.1-172.0 MPa; (3) stage III: homogenization temperatures = 130.1-386.0 °C, salinities = 1.40-9.73 and 34.07 wt.% NaCl equiv., and minimum pressures = 95.5-142.5 MPa; (4) stage IV: homogenization temperatures = 170-230 °C and salinities = 0.18-5.71 wt.% NaCl equiv. Various fluid inclusions were observed to contain H2O, CO2, CH4, SO2, C2H2, C2H4, C2H6, and (or) H2S, as well as solids that include halite, sylvite, anhydrite, chalcopyrite, hematite, molybdenite, and jamesonite. The δ18O and δD of the hydrothermal fluids vary from -4.4‰ to +8.5‰ and -81‰ to -61‰, respectively. Microthermometric and stable isotope data indicate that

  12. Geochemistry of Rare Earth Elements in Xikeng Ag-Pb-Zn Ore Deposit, South Anhui, China


    In this paper, a comparative study is done on the geochemical charateristics of REE in ore, ore-hosted rocks of Lantian group, granite related to ore deposit, and altered rocks for tracing origin of ore-forming materials. The result indicates that the ore-forming fluid and ore-forming materials for Xikeng silver-polymetallic ore deposit were derived from Yixian granite's magmatic activity. Water-rock reaction of the hydrothermal fluid with the carbonate-rich stratum led the altered rock to relatively enrich in HREE.

  13. Studies on Sulfating Roasting Process for Mianning Bastnasite and Baotou Mixed RE Concentrate Ore

    Miao Guangli


    Some processes of sulfating roasting and water leaching of crude Mianning RE concentrate ore, of fine Mianning RE concentrate ore, of Baotou RE concentrate ore and of their mixture were investigated.The result shows that the mixture of Mianning and Baotou RE concentrate ore has the optimum leaching rate and rate of recovery when the mixture ratio is 1:4.The recovery rate of the mixture is higher by 14.76% than that of crude Mianning RE concentrate ore, by 5.0 % than that of Mianning fine RE concentrate ore and by 2.4 % than that of Baotou RE concentrate ore.

  14. Experimental study on preferential solution flow during dump leaching of low-grade ores

    YIN Sheng-hua; WU Ai-xiang; SU Yong-ding; ZHANG Jie


    The phenomenon of preferential solution flow during dump leaching of low-grade ores was studied. The formative mechanism of preferential solution flow was investigated through analyzing the relationship between permeability and ore diameter,and the relationship between surface tension and ore diameter. The preferential solution flow happened within the fine ore area when the dump was unsaturated. And it could happen within the coarse ore area when the dump became saturated. The results of experiment show that the outflow of coarse ore area increases sharply with higher applied rate. The outflow of fine ore area is greater than that of coarse ore area when the applied rate is below 3.2 L/min, and the preferential solution flow happens in fine ore area. But the preferential solution flow happens in coarse ore area when the applied rate is higher than 3.2 L/min. The result of the experiment is consistent with the mechanism analyzing.

  15. Brazil's premier gold province. Part II: geology and genesis of gold deposits in the Archean Rio das Velhas greenstone belt, Quadrilátero Ferrífero

    Lobato, Lydia; Ribeiro-Rodrigues, Luiz; Vieira, Frederico


    Orogenic, gold deposits are hosted by rocks of the Archean Rio das Velhas greenstone belt in the Quadrilátero Ferrífero region, Minas Gerais state, Brazil, one of the major gold provinces in the world. The gold deposits occur at the base of the mafic-ultramafic succession, with the most important orebodies controlled by E-W-striking, strike-slip faults. The main mineralization styles are (1) structurally controlled, sulfide replacement zones in banded iron formation (BIF); (2) disseminated sulfide minerals and gold in hydrothermally altered rocks along shear zones; and (3) auriferous quartz-carbonate-sulfide veins and veinlets in mafic, ultramafic, and felsic volcanic rocks, and also in clastic sedimentary rocks. The most common host rocks for ore are metamorphosed oxide- and carbonate-facies banded iron (± iron-rich metachert) formations (e.g., the Cuiabá, São Bento and Raposos deposits) and the lapa seca unit, which is a local term for intensely carbonatized rock (e.g., the giant Morro Velho mine with >450 t of contained gold). Metabasalts host most of the remaining gold deposits. Mineralogical characteristics and fluid inclusion studies suggest variations in the H2O/CO2 ratio of a low-salinity, near-neutral, reducing, sulfur-bearing, ore fluid. The presence of abundant CH4-rich inclusions is related to reduction of the original H2O-CO2 fluid via interaction with carbonaceous matter in the wallrocks. Oxygen fugacity was close to that of graphite saturation, with variations likely to have been influenced by reaction with the carbonaceous matter. Carbon-rich phyllites and schists, which commonly bound ore-bearing horizons, seem to have played both a physical and chemical role in localizing hydrothermal mineral deposition. Microtextural studies indicate that gold deposition was mainly related to desulfidation reactions, and was paragenetically coeval with precipitation of arsenic-rich iron sulfide minerals. Carbon isotope data are compatible with dissolution of

  16. Geochemical Characteristics and Geological Significance of the Tawangshan gold deposit in Dongfang City, Hainan Province

    Xiong Ying


    Full Text Available The Tawangshan gold deposit is located in the southwest of the Gezhen ductile shear zone in southwestern Hainan Island. Major, trace and rare earth element characteristics of the least altered granites and altered granite ores, as well as the oxygen and hydrogen isotopic features of the quartz, the sulfur and lead isotopic features of the pyrites, galena from this deposit were systematically studied. The altered granite ores content of Fe2O3/(Fe2O3+FeO ranges from 0.409 to 0.410, showing strong magma reducibility. REE characteristics of the granite ores are similar to those of the least altered granites, indicating a close relationship between the mineralization and granite. Hydrogen and oxygen analysis results show that the content of 18OSMOW ranges from 7.7‰ to 16.3‰, δ18OH2O ranges from 1.0‰ to 6.8‰, suggesting that the ore-forming fluid was the dual nature of the metamorphic and magmatic hydrothermal. The compositions of sulfur isotope and lead isotope imply that the metallogenic materials of the deposit derived from the deep magma mixing with the shell source material contamination. Ore deposit geological features reflect the obvious characteristics of magmatic hydrothermal and porphyritic granite is mineralized rocks, implying the deposit was formed in the post-collisional extensional tectonic setting.


    Angelo Quintiliano Nunes da Silva


    Full Text Available The main iron ore processing plants in Brazil operate through reverse cationic flotation. Many studies have been conducted in order to improve flotation efficiency by optimization process variables. The pneumatic flotation cell stands out due to the simplicity to and to the intense contact particle/bubble promoted by the pulp feeding system. In this study, laboratory scale and pilot were conducted using a sample of itabirite iron ore. The objectives are evaluating the performance of this device using low grade iron ore, and drawing a comparison with laboratory scale tests on conventional flotation cell. The results indicate the potential application of pneumatic flotation cell to the ore tested. Adjustments in the feed particle size and process optimizations can be performed on the concentrate, reaching Fe and SiO2 grades used by the industry

  18. Microstructure of bentonite in iron ore green pellets.

    Bhuiyan, Iftekhar U; Mouzon, Johanne; Schröppel, Birgit; Kaech, Andres; Dobryden, Illia; Forsmo, Seija P E; Hedlund, Jonas


    Sodium-activated calcium bentonite is used as a binder in iron ore pellets and is known to increase strength of both wet and dry iron ore green pellets. In this article, the microstructure of bentonite in magnetite pellets is revealed for the first time using scanning electron microscopy. The microstructure of bentonite in wet and dry iron ore pellets, as well as in distilled water, was imaged by various imaging techniques (e.g., imaging at low voltage with monochromatic and decelerated beam or low loss backscattered electrons) and cryogenic methods (i.e., high pressure freezing and plunge freezing in liquid ethane). In wet iron ore green pellets, clay tactoids (stacks of parallel primary clay platelets) were very well dispersed and formed a voluminous network occupying the space available between mineral particles. When the pellet was dried, bentonite was drawn to the contact points between the particles and formed solid bridges, which impart strength to the solid compact.

  19. Carbothermal Upgrading of the Awaso Bauxite Ore using Waste ...



    Jun 1, 2015 ... Ore using Waste Pure Water Sachets as Reductant”, Ghana Mining Journal, Vol. ... content) and the emergence of low grade bauxite with high iron oxide content calls for ... effects on the alumina extraction process (Lu et al.,.


    Zoran Markovic


      This paper presents some investigation results about potassium ethyl xanthate (PEX) stability in water solution at higher pH and in presence of mineral chalcopyrite, related to flotation of copper minerals from copper ore...

  1. Measurement and Modelling of Blast Movement to Reduce Ore ...


    growth both from new discoveries and the develop- ment of Subika ... search have developed innovative tools and tech- niques to .... 7 Histogram of Horizontal Blast Displace ment from All Five .... Better QA/QC along the ore/waste boundaries.

  2. Radioanalysis of RE enrichment of ion adsorption type RE ores

    Zhao Shu Quan; Hu He Ping; Li Fu Sheng; Chen Ying Min; LiuShiMing


    Objective: To analyze the radioactivity in Rare Earth (RE) enrichment of ion adsorption type RE ores. Methods: Using HPGe-gamma spectrometer to analyze the activity ratio of gamma radionuclides in kind of samples, using FJ-2603 low background alpha, beta measurement apparatus to measure their total alpha and total beta activities, and using X-ray fluorescence spectrometer to analyze contents of La sub 2 O sub 3 and Y sub 2 O sub 3 , respectively. Results: HPGe gamma spectroscopy and X-ray fluorescence spectroscopy are simple, convenient and non-destructive methods of analyzing radionuclides and La sub 2 O sub 3 , Y sub 2 O sub 3 in RE enrichment of ion adsorption type RE ores, respectively. Conclusion: The basic data were provided for radiation protection and treatment of gas, liquid and solid waste in RE production of ion adsorption type RE ores; method and experience were provided for studying ion adsorption type RE ores

  3. By lithology Zbruch deposits (Lower Sarmatian Nikopol manganese ore Basin

    Bogdanovich V.V.


    Full Text Available Based on lithologic-paleogeographic study Zbruch layers of Nikopol manganese ore Basin sediments described lithological and genetic types of rocks and facies conditions of formation of deposits.

  4. Stripping Chronopotentiometry: An Alternative Method for the Determination of Gold in Geological Samples

    Nipaporn MEEPUN


    Full Text Available A stripping chronopotentiometric method was developed for reliable determination of gold in geological samples. Gold in gold ore and steam sediment samples was determined by constant current film stripping chronopotentiometry at a bare glassy carbon working electrode. The following optimum conditions were obtained: 0.5 M hydrochloric acid as a supporting electrolyte, an electrolysis potential of –0.6 V vs. saturated calomel electrode (SCE, an electrolysis time of 2 min and a constant oxidative current of +4 μA. A linear concentration range was obtained from 1.0 to 20 mg/l. The detection limit was 0.27 mg/l (n = 10 and the relative a standard deviations of 1.0 mg/l Au(III was 2.8 % (n = 10. In order to check the analytical accuracy, standard solution was spiked in a sample and the recoveries were found at 100.1 to 105.8 %. The results revealed that the quantity of gold in gold ore and sediment were 0.6 to 3.3 % and 0.9 to 1.2 %, respectively.

  5. Limitations in small artisanal gold mining addressed by educational components paired with alternative mining methods.

    Zolnikov, Tara R


    Current solutions continue to be inadequate in addressing the longstanding, worldwide problem of mercury emissions from small artisanal gold mining. Mercury, an inexpensive and easily accessible heavy metal, is used in the process of extracting gold from ore. Mercury emissions disperse, affecting human populations by causing adverse health effects and environmental and social ramifications. Many developing nations have sizable gold ore deposits, making small artisanal gold mining a major source of employment in the world. Poverty drives vulnerable, rural populations into gold mining because of social and economic instabilities. Educational programs responding to this environmental hazard have been implemented in the past, but have had low positive results due to lack of governmental support and little economic incentive. Educational and enforced intervention programs must be developed in conjunction with governmental agencies in order to successfully eliminate this ongoing problem. Industry leaders offered hopeful suggestions, but revealed limitations when trying to develop encompassing solutions to halt mercury emissions. This research highlights potential options that have been attempted in the past and suggests alternative solutions to improve upon these methods. Some methods include buyer impact recognition, risk assessment proposals exposing a cost-benefit analysis and toxicokinetic modeling, public health awareness campaigns, and the education of miners, healthcare workers, and locals within hazardous areas of mercury exposure. These methods, paired with the implementation of alternative mining techniques, propose a substantial reduction of mercury emissions.

  6. Gold induced apoptsis study

    Laustsen, Christoffer


    Introduction   Cancer cells are highly thermo sensitive. On the basis of an article in Nature the idea arose, for a new non-invasive thermotherapy technique, based on radio frequency inductive heating of nano gold particles in an MR-scanner. Thermotherapy is getting considerably attention...... at the moment, especially in the fields of lasers, they though have some problems concerning the placement of the tumor in the human body. Local heating by MR has tremendous advance in comparison too lasers. The first step is to validate the hypothesis of the inductive heating of the gold nano particles trough...... in silico methods are here proposed for apoptosis studies and for AMG studies.   Methods   MR - heating of high concentration micrometer gold and low concentration nano gold.   CSLM of ethidum bromide stained cell lines, with and witout gold and automated image processing.   AMG gold uptake study...

  7. Phanerozoic continental growth and gold metallogeny of Asia

    Goldfarb, Richard J.; Taylor, Ryan D.; Collins, Gregory S.; Goryachev, Nicolay A.; Orlandini, Omero Felipe


    ; and (8) Jurassic(?) ores on the margins of the Subumusu block in Myanmar and Malaysia. Circum-Pacific tectonism led to major orogenic gold province formation along the length of the eastern side of Asia between ca. 135 and 120 Ma, although such deposits are slightly older in South Korea and slightly younger in the Amur region of the Russian Southeast. Deformation related to collision of the Kolyma–Omolon microcontinent with the Pacific margin of the Siberia craton led to formation of 136–125 Ma ores of the Yana–Kolyma belt (Natalka, Sarylakh) and 125–119 Ma ores of the South Verkhoyansk synclinorium (Nezhdaninskoe). Giant ca. 125 Ma gold provinces developed in the Late Archean uplifted basement of the decratonized North China block, within its NE edge and into adjacent North Korea, in the Jiaodong Peninsula, and in the Qinling Mountains. The oldest gold-bearing magmatic–hydrothermal deposits of Asia include the ca. 485 Ma Duobaoshan porphyry within a part of the Tuva–Mongol arc, ca. 355 Ma low-sulfidation epithermal deposits (Kubaka) of the Omolon terrane accreted to eastern Russia, and porphyries (Bozshakol, Taldy Bulak) within Ordovican to Early Devonian oceanic arcs formed off the Kazakhstan microcontinent. The Late Devonian to Carboniferous was marked by widespread gold-rich porphyry development along the margins of the closing Ob–Zaisan, Junggar–Balkhash, and Turkestan basins (Amalyk, Oyu Tolgoi); most were formed in continental arcs, although the giant Oyu Tolgoi porphyry was part of a near-shore oceanic arc. Permian subduction-related deformation along the east side of the Indochina block led to ca. 300 Ma gold-bearing skarn and disseminated gold ore formation in the Truong Son fold belt of Laos, and along the west side to ca. 250 Ma gold-bearing skarns and epithermal deposits in the Loei fold belt of Laos and Thailand. In the Mesozoic Transbaikal region, extension along the basin margins subsequent to Mongol–Okhotsk closure was

  8. A geochemical assessment of possible lunar ore formation

    Haskin, Larry A.; Colson, Russell O.; Vaniman, David

    The Moon apparently formed without appreciable water or other relatively volatile materials. Interior concentrations of water or other volatile substances appear to be extremely low. On Earth, water is important to the genesis of nearly all types of ores. Thus, some have reasoned that only abundant elements would occur in ore concentrations. The definition and recognition of ores on the Moon challenge the imaginations and the terrestrial perceptions of ore bodies. Lunar ores included solar-wind soaked soils, which contain abundant but dilute H, C, N, and noble gases (including He-3). Oxygen must be mined; soils contain approximately 45 percent (wt). Mainstream processes of rock formation concentrated Si, Mg, Al, Fe, and Ca, and possibly Ti and Cr. The highland surface contains approximately 70 percent (wt) feldspar (mainly CaAl2Si2O8), which can be separated from some highland soils. Small fragments of dunite were collected; dunite may occur in walls and central peaks of some craters. Theoretical extensions of observations of lunar samples suggest that the Moon may have produced ores of trace elements. Some small fragments have trace-element concentrations 104 times higher than the lunar average, indicating that effective geochemical separations occurred; processes included fractional crystallization, silicate immiscibility, vaporization and condensation, and sulfide metamorphism. Operations of these processes acting on indigenous materials and on meteoritic material in the regolith could have produced ores. Infalling carbonaceous meteorites and comets have added water and hydrocarbons that may have been cold-trapped. Vesicles in basalts, pyroclastic beads, and reported transient events suggest gag emission from the lunar interior; such gas might concentrate and transport rare elements. Large impacts may disperse ores or produce them through deposition of heat at depth and by vaporization and subsequent condensation. The main problem in assessing lunar resources is

  9. Experimental determination of detection limits for performing neutron activation analysis for gold in the field

    Jarzemba, M.S.; Weldy, J.; Pearcy, E.; Prikryl, J.; Pickett, D.


    Measurements are presented of gold concentration in rock/soil samples by delayed neutron activation analysis using a device and method that are potentially field portable. The device consists of a polyethylene moderator and {sup 252}Cf as the source of neutrons for activating the samples and a high-purity germanium detector to measure the 412-keV gamma-ray emissions from activated gold. This information is used to extract the gold concentration in the sample. Two types of samples were investigated: (1) pure SiO{sub 2} doped with a known amount of gold chloride and (2) US Geological Survey standards. The former types were used to evaluate optimum device performance and to calibrate the device and method. The latter types were used to show typical system performance for the intended application (field exploration for gold deposits). It was found that the device was capable of determining gold concentrations to {approximately}10 ppb with a turnaround time (the sum of irradiation, decay, and counting times) of {approximately}10 days. For samples where the gold concentration was much higher (i.e., gold ore), turnaround times are {approximately}2 days and could be shortened further by sacrificing accuracy (e.g., lessening irradiation, decay, and counting times) or by augmenting source strength.

  10. Uranium and thorium recovery in thorianite ore-preliminary results

    Gaiotte, Joao V.M. [Universidade Federal de Alfenas, Pocos de Caldas, MG (Brazil); Villegas, Raul A.S.; Fukuma, Henrique T., E-mail:, E-mail: [Comissao Nacional de Energia Nuclear (CNEN), Pocos de Caldas, MG (Brazil). Lab. de Pocos de Caldas


    This work presents the preliminary results of the studies aiming to develop a hydrometallurgical process to produce uranium and thorium concentrates from thorianite ore from Amapa State, Brazil. This process comprises two major parts: acid leaching and Th/U recovery using solvent extraction strategies. Thorianite ore has a typical composition of 60 - 70% of thorium, 8 - 10% lead and 7 - 10% uranium. Sulfuric acid leaching operational conditions were defined as follows: acid/ore ratio 7.5 t/t, ore size below 65 mesh (Tyler), 2 hours leaching time and temperature of 100 deg C. Leaching tests results showed that uranium and thorium recovery exceeded 95%, whereas 97% of lead ore content remained in the solid form. Uranium and thorium simultaneous solvent extraction is necessary due to high sulfate concentration in the liquor obtained from leaching, so the Primene JM-T primary anime was used for this extraction step. Aqueous raffinate from extraction containing sulfuric acid was recycled to the leaching step, reducing acid uptake around 60%, to achieve a net sulfuric acid consumption of 3 t/t of ore. Uranium and thorium simultaneous stripping was performed using sodium carbonate solution. In the aqueous stripped it was added sulfuric acid at pH 1.5, followed by a second solvent extraction step using the tertiary amine Alamine 336. The following stripping step was done with a solution of sodium chloride, resulting in a final solution of 23 g L-1 uranium. (author)

  11. Orogenic-type copper-gold-arsenic-(bismuth) mineralization at Flatschach (Eastern Alps), Austria

    Raith, Johann G.; Leitner, Thomas; Paar, Werner H.


    Structurally controlled Cu-Au mineralization in the historic Flatschach mining district (Styria, Austria) occurs in a NE-SW to NNE-WSW oriented vein system as multiple steep-dipping calcite-(dolomite)-quartz veins in amphibolite facies metamorphic rocks (banded gneisses/amphibolites, orthogneisses, metagranitoids) of the poly-metamorphosed Austroalpine Silvretta-Seckau nappe. Vein formation postdated ductile deformation events and Eoalpine (Late Cretaceous) peak metamorphism but predated Early to Middle Miocene sediment deposition in the Fohnsdorf pull-apart basin; coal-bearing sediments cover the metamorphic basement plus the mineralized veins at the northern edge of the basin. Three gold-bearing ore stages consist of a stage 1 primary hydrothermal (mesothermal?) ore assemblage dominated by chalcopyrite, pyrite and arsenopyrite. Associated minor minerals include alloclasite, enargite, bornite, sphalerite, galena, bismuth and matildite. Gold in this stage is spatially associated with chalcopyrite occurring as inclusions, along re-healed micro-fractures or along grain boundaries of chalcopyrite with pyrite or arsenopyrite. Sericite-carbonate alteration is developed around the veins. Stage 2 ore minerals formed by the replacement of stage 1 sulfides and include digenite, anilite, "blue-remaining covellite" (spionkopite, yarrowite), bismuth, and the rare copper arsenides domeykite and koutekite. Gold in stage 2 is angular to rounded in shape and occurs primarily in the carbonate (calcite, Fe-dolomite) gangue and less commonly together with digenite, domeykite/koutekite and bismuth. Stage 3 is a strongly oxidized assemblage that includes hematite, cuprite, and various secondary Cu- and Fe-hydroxides and -carbonates. It formed during supergene weathering. Stage 1 and 2 gold consists mostly of electrum (gold fineness 640-860; mean = 725; n = 46), and rare near pure gold (fineness 930-940; n = 6). Gold in stage 3 is Ag-rich electrum (fineness 350-490, n = 12), and has a

  12. Crude oil as carrier of gold: petrological and geochemical evidence from Lannigou gold deposit in southwestern Guizhou, China

    庄汉平; 卢家烂; 傅家谟; 任炽刚; 邹德刚


    Organic matter is related closely to mineralization of Lannigou gold deposit in southwestern Guizhou, China, Regionally, the distribution of organic carbon agrees well with that of faults within which gold deposits are hosted. Studies on organic petrology show that pyrobiturnen, which is related most closely to mineralization, adheres to quartz vein or fills quartz veinlet. Proton-induced X-ray emission (PIXE) analysis shows an evident abundance of Au in pyrobitumen. Pyrobitumen paragenetically associates with pyrite and arsenopyrite which are the main carrier minerals of Au. The thermal simulation experiment indicates that about 99% of Au will be concentrated in oil phase in the coexisting system of oil and brine and rock. The role of crude oil in ore-forming process is: as carrier of Au, crude oil moves upwards, and undergoes thermal decomposition and thermochemical reduction when it encounters the oxidizing fluid within the Trassic turbidity; Au is thus released from crude oil, reduced and precipitat

  13. Study on the multi-sources of ore-forming materials and ore-forming fluids in the Huize lead-zinc ore deposit

    ZHANG Zhenliang; HUANG Zhilong; GUAN Tao; YAN Zaifei; GAO Derong


    The Huize large-sized Pb-Zn deposit in Yunnan Province, China, is characterized by favorable metallogenic background and particular geological settings. This suggested that the ore-forming mechanism is relatively unique. On the basis of geological features such as the contents of mineralization elements, the REE concentrations of gangue calcites, the REE concentrations of calcite veins in the NE-trending tectonic zone and the Pb, Sr, C, H and O isotopic compositions of different minerals, this paper presents that the ore-forming materials and ore-forming fluids of the deposit were derived from various types of strata or rocks. This is a very significant conclusion for us to further discuss the mineralization mechanism of the deposit at depth and establish an available genetic model.


    PENG; Sheng-lin; LIU; Liang-ming; LAI; Jian-qing


    The metallogenic theory of polygenetic compound ore deposit is the Important basis for location prediction of hidden ore deposits in diwa regions.It can play an important role in each step of prediction research,targeting procedure,acquiring information and integrating information.In this paper,the authors discusses how to construct geological concept by using of the metallogenic theory of polygenetic ore deposits for predicting targeting area,to arrange investigation and detection for getting enough useful information,and to analyze and integrate information for reaching a trustful prediction conclusion.According to these strategies,we conduct a successful prediction of location of hidden ore bodies in the outer of the Fenghuangshan copper mine,a principal producing mine in Tongling Cu-Au district.

  15. Transport network and flow mechanism of shallow ore-bearing magma in Tongling ore cluster area

    DENG; Jun; WANG; Qingfei; HUANG; Dinghua


    Abundant studies revealed that shallow intrusions of the Yanshanian epoch resulted in the mass mineralization of the Tongling region. Various evidences showed there existed a concealed magma chamber at -10 km depth in the middle part of this region during Yanshanian epoch, from which the ore-forming magma was generated and then transported to the superficial layer. Yet the transport network and flow mechanism of the shallow ore-bearing magma, the key problem associ- ated with ore-forming process, was relatively little focused on. Integrate analysis of structural me- chanics, statistical fractal and geological facts suggested that NE trending high-angle fold-related thrust faults and the tessellated basement ones served as the main pathways for the shallow magma's transporting, moreover, the saddle void spaces among adjacent strata in the folds upon this fault system provided the place for magma's emplacement. So the folds in the upper part and faults in the lower part of the upper crust constituted the fluid's transport and emplacement network. During the deformation of geologic body with multi-layer structure, the layers in the upper part tended to fold when received the jacking stress from the lower part, while the lower one inclined to fault undergoing loads of the upper part. And the producing probability of this structure assemblage was highly increased in the condition, such as in the Tongling area, that the mechanic rigidity of the lower layers was stronger than that of the upper ones. For the pre-existence of fluid-conducting network, the top magma with high volatile in the magma chamber transported rapidly to the superficial layer in dyking pattern, located in the void spaces of folds, filled and reconstructed them. The sudden drop of pressure caused the fluid unmixing from the magma and mass ore-forming elements concentration. Pulse activity of the dyking may be the principal reason why magmatic bodies in the Tongling area were spatially

  16. Ceramic colorant from untreated iron ore residue.

    Pereira, Oscar Costa; Bernardin, Adriano Michael


    This work deals with the development of a ceramic colorant for glazes from an untreated iron ore residue. 6 mass% of the residue was added in suspensions (1.80 g/cm(3) density and 30s viscosity) of white, transparent and matte glazes, which were applied as thin layers (0.5mm) on engobeb and not fired ceramic tiles. The tiles were fired in laboratory roller kiln in a cycle of 35 min and maximum temperatures between 1050 and 1180°C. The residue and glazes were characterized by chemical (XRF) and thermal (DTA and optical dilatometry) analyses, and the glazed tiles by colorimetric and XRD analyses. The results showed that the colorant embedded in the transparent glaze results in a reddish glaze (like pine nut) suitable for the ceramic roof tile industry. For the matte and white glazes, the residue has changed the color of the tiles with temperature. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Ferrite grade iron oxides from ore rejects

    K S Rane; V M S Verenkar; P Y Sawant


    Iron oxyhydroxides and hydroxides were synthesized from chemically beneficiated high SiO2/Al2O3 low-grade iron ore (57.49% Fe2O3) rejects and heated to get iron oxides of 96–99.73% purity. The infrared band positions, isothermal weight loss and thermogravimetric and chemical analysis established the chemical formulas of iron-oxyhydroxides as -FeOOH.0.3H2O; -FeOOH.0.2H2O and amorphous FeOOH. The thermal products of all these were -Fe2O3 excepting that of -FeOOH.0.3H2O which gave mainly -Fe2O3 and some admixture of -Fe2O3. The hydrazinated iron hydroxides and oxyhydroxides, on the other hand, decomposed autocatalytically to mainly -Fe2O3. Hydrazine method modifies the thermal decomposition path of the hydroxides. The saturation magnetization, s, values were found to be in the range 60–71 emu g–1 which are close to the reported values for -Fe2O3. Mechanism of the -Fe2O3 formation by hydrazine method is discussed.

  18. The Metamorphic Rocks-Hosted Gold Mineralization At Rumbia Mountains Prospect Area In The Southeastern Arm of Sulawesi Island, Indonesia

    Hasria Hasria


    Full Text Available Recently, in Indonesia gold exploration activities  are not only focused along volcanic-magmatic belts, but also starting to shift along metamorphic and sedimentary terrains. The study area is located in Rumbia mountains, Bombana Regency, Southeast Sulawesi Province. This paper is aimed to describe characteristics of alteration and ore mineralization associated  with metamorphic rock-related gold deposits.  The study area is found the placer and  primary gold hosted by metamorphic rocks. The gold is evidently derived from gold-bearing quartz veins hosted by Pompangeo Metamorphic Complex (PMC. These quartz veins are currently recognized in metamorphic rocks at Rumbia Mountains. The quartz veins are mostly sheared/deformed, brecciated, irregular vein, segmented and  relatively massive and crystalline texture with thickness from 1 cm to 15.7 cm. The wallrock are generally weakly altered. Hydrothermal alteration types include sericitization, argillic, inner propylitic, propylitic, carbonization and carbonatization. There some precious metal identified consist of native gold and ore mineralization including pyrite (FeS2, chalcopyrite (CuFeS2, hematite (Fe2O3, cinnabar (HgS, stibnite (Sb2S3 and goethite (FeHO2. The veins contain erratic gold in various grades from below detection limit <0.0002 ppm to 18.4 ppm. Based on those characteristics, it obviously indicates that the primary gold deposit present in the study area is of orogenic gold deposit type. The orogenic gold deposit is one of the new targets for exploration in Indonesia

  19. Cyanide speciation at four gold leach operations undergoing remediation

    Johnson, Craig A.; Grimes, David J.; Leinz, Reinhard W.; Rye, Robert O.


    Analyses have been made of 81 effluents from four gold leach operations in various stages of remediation to identify the most-persistent cyanide species. Total cyanide and weak acid-dissociable (WAD) cyanide were measured using improved methods, and metals known to form stable cyanocomplexes were also measured. Typically, total cyanide greatly exceeded WAD indicating that cyanide was predominantly in strong cyanometallic complexes. Iron was generally too low to accommodate the strongly complexed cyanide as Fe(CN)63- or Fe(CN)64-, but cobalt was abundant enough to implicate Co(CN)63- or its dissociation products (Co(CN)6-x(H2O)x(3-x)-). Supporting evidence for cobalt-cyanide complexation was found in tight correlations between cobalt and cyanide in some sample suites. Also, abundant free cyanide was produced upon UV illumination. Iron and cobalt cyanocomplexes both photodissociate; however, the iron concentration was insufficient to have carried the liberated cyanide, while the cobalt concentration was sufficient. Cobalt cyanocomplexes have not previously been recognized in cyanidation wastes. Their identification at four separate operations, which had treated ores that were not especially rich in cobalt, suggests that cobalt complexation may be a common source of cyanide persistence. There is a need for more information on the importance and behavior of cobalt cyanocomplexes in ore-processing wastes at gold mines.

  20. Carbon isotope evidence for a magmatic origin for Archaean gold-quartz vein ore deposits

    Burrows, D. R.; Wood, P. C.; Spooner, E. T. C.


    Sediments from three sites in the Santa Barbara Basin were examined with a 160X power light microscope and TEM equipment to characterize the magnetostatic bacteria (MB) in the samples. Both the free magnetite and the crystals in the MB in the samples had lengths from 40-60 nm in length and increased in size from one end to the next. An intact magnetosome was also observed. Scanning the sediments with saturation isothermal remanent magnetization (SIRM) and altering field demagnetization techniques using a SQUID magnetometer yielded coercivity spectra which showed that the primary remanence carrier in the sediments was single domain magnetite. Although it is expected that the predominance of the bacterial magnetite component will decrease with depth in the open ocean basin, single-domain bacteria as old as 50 Myr have been observed in oceanic sediments.

  1. Control of Ore Loss and Dilution at AngloGold Ashanti, Iduapriem ...



    Jun 1, 2016 ... Mine using Blast Movement Monitoring System”, Ghana Mining Journal, Vol. 16, No. 1, pp. .... production holes and 102 mm for pre-split. The current blast ..... line for the shot was placed at the centre of the reefs hence the ...

  2. Gold in the Books



    In the present Chinese market, more and more businessmen turn to the profit-making trade. Even some counters in the bookstores are selling gold rings, necklaces, bracelets, etc. One day a school teacher asked a store assistant,“Why are you selling gold in your bookstore?”

  3. Gold-Mining

    Raaballe, J.; Grundy, B.D.


    of operating gold mines. Asymmetric information on the reserves in the mine implies that, at a high enough price of gold, the manager of high type finds the extraction value of the company to be higher than the current market value of the non-operating gold mine. Due to this under valuation the maxim of market...... value maximization forces the manager of high type to extract the gold.The implications are three-fold. First, all managers (except the lowest type) extract the gold too soon compared to the first-best policy of leaving the gold in the mine forever. Second, a manager of high type extracts the gold...... sooner than a manager of lower type. Third, a non-operating gold mine is valued as being of the lowest type in the pool and all else equal, high-asymmetri mines are valued lower than low-asymmetri mines. In a qualitative sense these results are robust with respect to different assumptions (re cost...

  4. Gold Minerogenetic Prognosis Using Satellite Data: Case Study of Paishanlou Gold Mine, Liaoning Province, China

    Malogo J M Kongola; Wang Ende


    The major scientific goal of using satellite data for mineral prospecting in the study area was two-fold: (a) mapping geology, faults and fractures that localize ore deposits; (b) recognizing hydrothermally altered rocks by interpreting their spectral signatures. The lithology, properties, and geological relations of the rocks were key to understanding such varied phenomena as convection, melting and transport mechanisms, rock deformation and alteration, the sources of magnetic anomalies, and the hydrothermal circulation and formation of gold deposits. Satellite data were enhanced using the following techniques: band combinations, ratios, directional sharpening filtering, Laplacian transform, spatial convolution, and density slicing. By mapping a larger area, the Paishanlou Gold Mine was discovered to be located within an accommodation zone, with three significant populations of faults having bearings of 95, 145, and 180 degrees. Faults bearing 145 degrees make up the faults of the main shear zone. The faults bearing 180 degrees have large sinistral offsets, typically 1.5 km, and form a synthetic-antithetic set with the faults bearing 145 degrees, which have dextral displacements of tens of meters. In the Landsat ETM+ image composed of bands 7-4-2 RGB, gneiss rocks were clearly seen as red purple, and granitic and plagioclase bodies in pale brown/pink. The strongest alteration signature in the image was found along the detachment fault antiform located closest to the mine and the plutons responsible for the Paishanlou gold mineralization. Satellite image interpretation coupled with field surveys led to the identification of iron mineral composites, hydrothermally altered areas, fractures, and an accommodation zone. These anomalies finally resulted in the discovery of three new gold-mineralized sites.

  5. Fluorosilicone and silicone o-ring aging study.

    Bernstein, Robert; Gillen, Kenneth T.


    Fluorosilicone o-ring aging studies were performed. These studies examined the compressive force loss of fluorosilicone o-rings at accelerated (elevated) temperatures and were then used to make predictions about force loss at room temperature. The results were non-Arrhenius with evidence for a lowering in Arrhenius activation energies as the aging temperature was reduced. The compression set of these fluorosilicone o-rings was found to have a reasonably linear correlation with the force loss. The aging predictions based on using the observed curvature of the Arrhenius aging plots were validated by field aged o-rings that yielded degradation values reasonably close to the predictions. Compression set studies of silicone o-rings from a previous study resulted in good correlation to the force loss predictions for the fluorosilicone o-rings from this study. This resulted in a preliminary conclusion that an approximately linear correlation exists between compression set and force decay values for typical fluorosilicone and silicone materials, and that the two materials age at similar rates at low temperatures. Interestingly, because of the observed curvature of the Arrhenius plots available from longer-term, lower temperature accelerated exposures, both materials had faster force decay curves (and correspondingly faster buildup of compression set) at room temperature than anticipated from typical high-temperature exposures. A brief study on heavily filled conducting silicone o-rings resulted in data that deviated from the linear relationship, implying that a degree of caution must be exercised about any general statement relating force decay and compression set.

  6. Discriminating fluid source regions in orogenic gold deposits using B-isotopes

    Lambert-Smith, James S.; Rocholl, Alexander; Treloar, Peter J.; Lawrence, David M.


    The genesis of orogenic gold deposits is commonly linked to hydrothermal ore fluids derived from metamorphic devolatilization reactions. However, there is considerable debate as to the ultimate source of these fluids and the metals they transport. Tourmaline is a common gangue mineral in orogenic gold deposits. It is stable over a very wide P-T range, demonstrates limited volume diffusion of major and trace elements and is the main host of B in most rock types. We have used texturally resolved B-isotope analysis by secondary ion mass spectrometry (SIMS) to identify multiple fluid sources within a single orogenic gold ore district. The Loulo Mining District in Mali, West Africa hosts several large orogenic gold ore bodies with complex fluid chemistry, associated with widespread pre-ore Na- and multi-stage B-metasomatism. The Gara deposit, as well as several smaller satellites, formed through partial mixing between a dilute aqueous-carbonic fluid and a hypersaline brine. Hydrothermal tourmaline occurs as a pre-ore phase in the matrix of tourmalinite units, which host mineralization in several ore bodies. Clasts of these tourmalinites occur in mineralized breccias. Disseminated hydrothermal and vein hosted tourmaline occur in textural sites which suggest growth during and after ore formation. Tourmalines show a large range in δ11B values from -3.5 to 19.8‰, which record a change in fluid source between paragenetic stages of tourmaline growth. Pre-mineralization tourmaline crystals show heavy δ11B values (8-19.8‰) and high X-site occupancy (Na ± Ca; 0.69-1 apfu) suggesting a marine evaporite source for hydrothermal fluids. Syn-mineralization and replacement phases show lighter δ11B values (-3.5 to 15.1‰) and lower X-site occupancy (0.62-0.88 apfu), suggesting a subsequent influx of more dilute fluids derived from devolatilization of marine carbonates and clastic metasediments. The large, overlapping range in isotopic compositions and a skew toward the

  7. Lode-gold mineralization in the Tanami region, northern Australia

    Huston, David L.; Vandenberg, Leon; Wygralak, Andrew S.; Mernagh, Terrence P.; Bagas, Leon; Crispe, Andrew; Lambeck, Alexis; Cross, Andrew; Fraser, Geoff; Williams, Nick; Worden, Kurt; Meixner, Tony; Goleby, Bruce; Jones, Leonie; Lyons, Pat; Maidment, David


    at an angle consistent with tensional fractures opened during E-W- to ENE-WSW-directed transpression. Many of these deposits are hosted by reactive rock units such as carbonaceous siltstone and iron formation. Ore deposition occurred at depths ranging from 1.5 to 11 km from generally low to moderate salinity carbonic fluids with temperatures from 200 to 430°C, similar to lode-gold fluids elsewhere in the world. These fluids are interpreted as the product of metamorphic dewatering caused by enhanced heat flow, although it is also possible that the fluids were derived from coeval granites. Lead isotope data suggest that lead in the ore fluids had multiple sources. Hydrogen and oxygen isotope data are consistent with both metamorphic and magmatic origins for ore fluids. Gold deposition is interpreted to be caused by fluid unmixing and sulfidation of host rocks. Fluid unmixing is caused by three different processes: (1) CO2 unmixing caused by interaction of ore fluids with carbonaceous siltstone; (2) depressurization caused by pressure cycling in shear zones; and (3) boiling as ore fluids move to shallow levels. Deposits in the Tanami region may illustrate the continuum model of lode-gold deposition suggested by Groves (Mineralium Deposita 28:366-374, 1993) for Archean districts.

  8. International SUSMIN-project aims at sustainable gold mining in EU

    Backnäs, Soile; Neitola, Raisa; Turunen, Kaisa; Lima, Alexandre; Fiúza, António; Szlachta, Malgorzata; Wójtowicz, Patryk; Maftei, Raluca; Munteanu, Marian; Alakangas, Lena; Baciu, Calin; Fernández, Dámaris


    Although the gold demand has been constantly increasing in past years, the commodity findings have been decreasing and the extraction of gold has complicated due to increasing complexity and decreasing grade of the ores. Additionally, even gold mining could increase economical development, it has also challenges in eco-efficiency and extraction methods (e.g. cyanide). Thus, the novel energy and resource-efficient methods and technologies for mineral processing should be developed to concentrate selectively different gold bearing minerals. Furthermore, technologies for efficient treatment of mine waters, sustainable management of wastes, and methods to diminish environmental and social impacts of mining are needed. These problems will be addressed by the three year long project SUSMIN. The SUSMIN-project identifies and evaluates environmental impacts and economical challenges of gold mining within EU. The objective of the project is to increase the transnational cooperation and to support environmentally, socially and economically sustainable viable gold production. The focus is to develop and test geophysical techniques for gold exploration, eco-efficient ore beneficiation methods and alternatives for cyanide leaching. Additionally, the research will improve treatment methods for mine waters by the development and testing of advanced adsorbents. The research on socio-economic issues pursues to develop tools for enhancing the mechanisms of the corporate social responsibility as well as community engagement and management of the relations with the stakeholders. Moreover, with the environmental risk assessment and better knowledge of the geochemistry and long-term transformation of the contaminants in mining wastes and mine waters, the mining companies are able to predict and prevent the impacts to the surrounding environment, resulting in an improved environmental management solution. The SUSMIN consortium led by Geological Survey of Finland (GTK) includes seven

  9. Gamma Spectrometric Analysis of Iron Ore Samples of Arak, Iran

    Reza Pourimani


    Full Text Available Introduction Iron ore is one of the most important natural raw materials that is widely used for manufacturing iron and steel. This type of ore contains various amounts of radionuclides; thus, exposing workers handling their extraction, transportation, and processing to radiation. Materials and Methods In this study, 12 ore samples (each mass weighing about 2 kg were collected from the iron ore mining areas of Arak region, Iran. The specific activities of 226Ra, 232Th, and 40K were determined usinggamma-ray spectrometry method employing high-purity germanium (HPGe detector. Results The specific activities of 226Ra, 232Th, and 40K in samples were 9.39-271.70 Bq/kg, -3 Sv/y suggested in International Commission of Radiological Protection (ICRP Publication 82. Conclusion The gamma ray spectrometric analysis showed that the specific activities of natural radionuclides in samples, except for limonite ore, were within the worldwide range. The effective dose received by workers was much lower than the maximum acceptable value (1000 μSv/y; therefore, the level of radiations in this mine had no adverse consequences for public health.

  10. Existing State and Partitioning of Rare Earth on Weathered Ores


    The existing state and partitioning of rare earth (RE) on weathered ores in Longnan County (LN), Xingfeng County(XF) and Ninghua County(NH) were characterized systematically by standard geological analytical methods. It is found that RE in the weathered rare earth ores exist as four phases: (a) water soluble, (b) ion-exchangeable, (c) colloidal sediment (oxides), (d) minerals, in which mainly as ion exchangeable phase, accounting for nearly 80% of total RE,with about 20% in the form of colloid sediment phase and mineral phase, but very little as aqueous soluble phase. These rare earth partitioning were mainly chosen mid-heavy RE elements, occupying above 60%, but not equal in the four phases. The mid-heavy RE elements were primarily enriched in the ion exchangeable phase up to 40%, while the containment of cerium dioxide is below 2%. The cerium deficiency occurs in the ion exchangeable phase in weathered ore. It results from that the Ce3+ is oxidized into Ce4+ and changes into CeO2. For LN ore, the containment of Y is high in weathered ore because Y-minerals are abundant in original rock.

  11. Microbial Beneficiation of Salem Iron Ore Using Penicillium purpurogenum

    Mishra, M.; Pradhan, M.; Sukla, L. B.; Mishra, B. K.


    High alumina and silica content in the iron ore affects coke rate, reducibility, and productivity in a blast furnace. Iron ore is being beneficiated all around the world to meet the quality requirement of iron and steel industries. Choosing a beneficiation treatment depends on the nature of the gangue present and its association with the ore structure. The advanced physicochemical methods used for the beneficiation of iron ore are generally unfriendly to the environment. Biobeneficiation is considered to be ecofriendly, promising, and revolutionary solutions to these problems. A characterization study of Salem iron ore indicates that the major iron-bearing minerals are hematite, magnetite, and goethite. Samples on average contains (pct) Fe2O3-84.40, Fe (total)-59.02, Al2O3-7.18, and SiO2-7.53. Penicillium purpurogenum (MTCC 7356) was used for the experiment . It removed 35.22 pct alumina and 39.41 pct silica in 30 days in a shake flask at 10 pct pulp density, 308 K (35 °C), and 150 rpm. In a bioreactor experiment at 2 kg scale using the same organism, it removed 23.33 pct alumina and 30.54 pct silica in 30 days at 300 rpm agitation and 2 to 3 l/min aeration. Alumina and silica dissolution follow the shrinking core model for both shake flask and bioreactor experiments.

  12. On the use of bastnasite ore as a phosphor material

    Mohapatra, M., E-mail:; Natarajan, V.; Rajeswari, B.; Dhobale, A.R.; Godbole, S.V.


    Bastnasite ore obtained from Indian Rare Earth (IRE) was investigated for its possible use as a phosphor material. The material was characterized by X-ray diffraction (XRD), energy dispersive X-ray fluorescence (EDXRF), photoacoustic spectroscopy (PAS), photoluminescence (PL) and electron paramagnetic resonance spectroscopy (EPR) techniques. XRD studies revealed the semi processed ore to be consisting of single phase CeO{sub 2} with no other impurities. EDXRF studies revealed the presence of ‘Th’ and traces of ‘Sm’ along with ‘Ce’ in the sample. PAS studies revealed the presence of strong charge transfer from oxygen to cerium in the system. PL studies confirmed the presence of at least four trivalent rare earths, viz. Sm, Eu, Dy and Tb in the system in trace quantities. The emission spectrum and decay time data were evaluated. It was observed that the rare earth ions are situated at distorted sites in the system surrounded by defect centers. EPR studies confirmed the presence of Ce{sup 3+}in the system along with electron trapped in oxygen ion vacancies. CIE indices for the ore sample were evaluated and it was seen that the overall emission from the system was in the ‘magenta’ region of the visible spectrum. The emission intensities were also compared with that of commercial samples. -- Highlights: • Characterization of bastnasite ore as a phosphor material. • Role of RE impurities in the luminescence • CIE index of the bastnasite ore.

  13. Flotation technology of refractory low-grade molybdenum ore

    Du Shuhua; Luo Zhenfu


    Because of the low grade,high oxidation rate and the accumulation of little associated metal sulfide ore in the molybdenum concentrate during flotation,the Qingyang molybdenum ore is difficult to beneflciate.The experimental studies of grinding fineness,the amount of roughing modifier,depressant and collector were completed.In the cleaning process,the contrast experiments of one regrinding.the regrinding and scrubbing,two-stage regrinding was carried.The result shows that the grade of molybdenum ore concentrate is 45.31%,the recovery is 65.98% and the rich ore ratio reaches 20.59% by the regrinding and scrubbing seven cleaning,the regrinding of concentrations from middling of molybdenum-sulfur separation.The regularly-concentrated material from the apparatus was as the middling products.Hence,ideal beneficiation index can be obtained with a rational mineral processing,which offers new beneficiating technology for the refractory low-grade molybdenum ore in China.


    S.K. Kawatra; T.C. Eisele; J.A. Gurtler; C.A. Hardison; K. Lewandowski


    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. Primary examples of this are copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process, and advanced ironmaking processes, where binders must function satisfactorily over an extraordinarily large range of temperatures (from room temperature up to over 1200 C). As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching and advanced primary ironmaking.

  15. 16 CFR Appendix to Part 23 - Exemptions Recognized in the Assay for Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled...


    ... Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled Gold Plate, Silver, and Platinum Industry...—Exemptions Recognized in the Assay for Quality of Gold Alloy, Gold Filled, Gold Overlay, Rolled Gold Plate... be considered in any assay for quality of a gold filled, gold overlay and rolled gold plate industry...

  16. Effects of laboratory treatments on silver and other elements in native gold

    Campbell, W.L.; Mosier, E.L.; Antweiler, J.C.


    Interpretation of the element content of gold and of alloy proportions of gold and silver may have useful applications in prospecting and ore genesis studies. The commonly used methods of concentration and recovery of gold for analysis (acid leach, roasting, or amalgamation), however, alter the content of silver and other elements in the gold. The treatment of gold with four mineral acids (HF, HCL, H2S04, and HNO3) and combinations of these acids, amalgamation of the gold, and roasting the gold in a muffle furnace at 650°C for 8 hours caused losses of 0-100 percent of the elements studied. In some of the samples studied these treatments also caused losses totaling as much as 50 percent, by weight, of the silver content (which made up 20 percent of the total sample weight). The other elements studied show similar behavior to a lesser extent. The results of these studies show that before one interprets compositional analyses for prospecting or other applications he must know to what extent a recovery treatment changes the composition of the elements.

  17. Signs and symptoms of mercury-exposed gold miners

    Stephan Bose-O'Reilly


    Full Text Available Objectives: Gold miners use mercury to extract gold from ore adding liquid mercury to the milled gold-containing ore. This results in a mercury-gold compound, called amalgam. Miners smelt this amalgam to obtain gold, vaporizing it and finally inhaling the toxic mercury fumes. The objective was to merge and analyze data from different projects, to identify typical signs and symptoms of chronic inorganic mercury exposure. Material and Methods: Miners and community members from various artisanal small-scale gold mining areas had been examined (Philippines, Mongolia, Tanzania, Zimbabwe, Indonesia. Data of several health assessments were pooled. Urine, blood and hair samples were analyzed for mercury (N = 1252. Questionnaires, standardized medical examinations and neuropsychological tests were used. Participants were grouped into: Controls (N = 209, living in an exposed area (N = 408, working with mercury as panners (N = 181, working with mercury as amalgam burners (N = 454. Chi2 test, linear trend test, Mann-Whitney test, Kruskal-Wallis test, correlation coefficient, Spearman’s rho, and analysis of variance tests were used. An algorithm was used to define participants with chronic mercury intoxication. Results: Mean mercury concentrations in all exposed subgroups were elevated and above threshold limits, with amalgam burners showing highest levels. Typical symptoms of chronic metallic mercury intoxication were tremor, ataxia, coordination problems, excessive salivation and metallic taste. Participants from the exposed groups showed poorer results in different neuropsychological tests in comparison to the control group. Fifty-four percent of the high-exposed group (amalgam burners were diagnosed as being mercury-intoxicated, compared to 0% within the control group (Chi2 p < 0.001. Conclusions: Chronic mercury intoxication, with tremor, ataxia and other neurological symptoms together with a raised body burden of mercury was clinically diagnosed in

  18. The production and use of citric acid for the removal of potassium from the iron ore concentrate of the Sishen Iron Ore Mine, South Africa

    Peter J. Williams


    Full Text Available The depletion of the richer iron ore worldwide has made it necessary to process lower quality iron ore. Certain substances, such as potassium, contained within the lower quality iron ore, have a detrimental effect on the smelting process during steel manufacturing. Therefore, international steel-making companies charge penalties when purchasing iron ore concentrates containing high concentrations of potassium. To date, lower quality iron ore has been blended with high quality iron ore in an attempt to alleviate the potassium concentrations in the export iron ore; however, the ratio of low quality iron ore to high quality iron ore is increasing, thereby becoming an escalating problem within the economic functioning of the Sishen Iron Ore Mine. It has, therefore, become necessary to develop an economically viable and environmentally friendly process to reduce the high potassium concentrations contained in the iron ore concentrate of the Sishen Iron Ore Mine. In this study, we compared solid substrate and submerged fermentation using Aspergillus niger for the production of citric acid, which is used for the chemical leaching of potassium from the iron ore concentrate. It was found that submerged fermentation proved to be more economical and efficient, producing a maximum citric acid concentration of 102.3 g/L in 96 h of fermentation. ‘Heap leaching’ simulation experiments were found to be uneconomical, due to the required addition of fungal growth medium every 5 days as a result of growth factor depletion within this time; however, this process removed 17.65% of the potassium from the iron ore concentrate. By contrast, chemical leaching of potassium from the iron ore concentrate proved to be most efficient when using a 1 mol citric acid leaching solution at 60 ºC, removing 23.53% of the potassium contained within the iron ore concentrate. Therefore, the most economical and efficient process for the removal of potassium from the iron

  19. Hydrocarbon-mediated gold and uranium concentration in the Witwatersrand Basin, South Africa

    Fuchs, Sebastian; Williams-Jones, Anthony; Schumann, Dirk; Couillard, Martin; Murray, Andrew


    The Witwatersrand deposits in South Africa represent the largest repository of gold in the World and a major resource of uranium. The genesis of the gold and uranium ores in the quartz-pebble conglomerates (reefs), however, is still a matter of considerable discussion. Opinion has been divided over whether they represent paleo-placers that have been partly remobilised by hydrothermal fluids or if the mineralisation is entirely hydrothermal in origin. In addition, recently published models have proposed a syngenetic origin for the gold involving bacterially-mediated precipitation from meteoric water and shallow seawater. An important feature of the gold and uranium mineralisation in the reefs is the strong spatial association with organic matter. In some reefs, up to 70% of the gold and almost the entire uranium resource is spatially associated with pyrobitumen seams, suggesting a genetic relationship of the gold-uranium mineralisation with hydrocarbons. Here we report results of a study of the Carbon Leader Reef, using high-resolution scanning and transmission electron microscopy (SEM / TEM) and LA-ICP-MS that provide new insights into the role of hydrocarbons in the concentration of the gold and uranium. A detailed examination revealed gold monocrystals containing numerous rounded or elliptical inclusions filled with pyrobitumen. We interpret these inclusions to record the crystallisation of the gold around droplets of a hydrocarbon liquid that migrated through the Witwatersrand basin, and was converted to pyrobitumen by being heated. We propose that the gold was transported in a hydrothermal fluid as a bisulphide complex and that this fluid mixed with the hydrocarbon liquid to form a water-oil emulsion. The interaction between the two fluids caused a sharp reduction in fO2 at the water-oil interface, which destabilised the gold-bisulphide complexes, causing gold monocrystals to precipitate around the oil droplets. In contrast to the gold, uraninite, the principal

  20. Reworking Intensity—A Key Factor Leading to the Formation of Superlarge Gold Deposits in Greenstone Belts and Metamorphosed Microclastic Rocks in China

    王秀璋; 陆德复; 等


    The greenstone belt and metamorphosed microclastic rock-type superlarge gold deposits in China are hosted in metamorphic rocks and later intrusive bodies.Sedimentation.regional metamorphism and mineralization contributed a lot to the formation of the deposits,so did remelting magmatic process to some deposits,but the deposits were finally formed by reworking processes.The key factor leading to the formation of superlarge gold deposits is the reworking intensity,which for superlarge gold deposits is reflected by the large-scale reworked source rocks and even ore materials of various sources,strongly oxidized ore-forming fluids with a long and repeated active history and stable geothermal heat current.The factor which decides the reworking intensity is the network consisting of structures of different classes.

  1. Auriferous Quartz Veins from the Dongping Gold Deposit,NW Hebei Province and Metallogenesis—Fluid Inclusion Rb—Sr Isochron Evidence

    莫测辉; 王秀璋; 等


    The Dongping gold deposit,situated on the northern margin of the North China Platform,is a composite deposit composed of auriferous quartz vein-type and altered rock-type ore bodies.It is hosted in the inner contact zone of an alkaline intrusion which was intruded in to Archean metamorphic rocks and was formed not later than the Hercynian period.Auriferous quartz veins of the deposit are dated with the fluid inclusion Rb-Sr isochron method at 103±4Ma ,indicating that the gold deposit was formed in the Yenshanian period,86Sr/86Sr source tracing shows the ore-forming materials came dominantly from alkaline intrusions.These results combined with other isotope and REE data,suggest that the Dongping gold deposit is not a traditiolal magmatic hydrothermal deposit,but a reworked hydrothermal deposit related to heated and evolved meteoric water.

  2. Geochemical features of gold-quartz veins in granitoid intrusives and terrigenous masses of the Yana-Kolyma folded belt in the northeast of Russia

    Volkov, A. V.; Sidorov, A. A.; Savva, N. E.; Kolova, E. E.; Murashov, K. Yu.; Sidorova, N. V.


    The main task of this study was to reveal geochemical and distinctive features of gold-quartz vein ores of deposits in granitoid intrusive bodies and in terrigenous black-schist masses of the Yana-Kolyma folded belt. The results obtained point to the significant role of metamorphism of the enclosing terrigenous carbonaceous masses in ore formation of both types of deposits. The established facts are not contradictory to the metamorphic-magmagene model of the formation of gold deposits in the Yana-Kolyma belt. The geochemical similarity of both types of deposits shows that these are products of the same orogenic system, which confirms the validity of combining these deposits to form a unified gold-quartz formation.

  3. Chemical state mapping of heterogeneous reduction of iron ore sinter

    Kimura, M.; Takeichi, Y.; Murao, R.; Obayashi, I.; Hiraoka, Y.; Liu, Y.


    Iron ore sinter constitutes the major component of the iron-bearing burden in blast furnaces, and its reduction mechanism is one of the keys to improving the productivity of ironmaking. Iron ore sinter is composed of multiple iron oxide phases and calcium ferrites (CFs), and their heterogeneous reduction was investigated in terms of changes in iron chemical state: FeIII, FeII, and Fe0 were examined macroscopically by 2D X-ray absorption and microscopically by 3D transmission X-ray microscopy (TXM). It was shown that the reduction starts at iron oxide grains rather than at calcium ferrite (CF) grains, especially those located near micropores. The heterogeneous reduction causes crack formation and deteriorates the mechanical strength of the sinter. These results help us to understand the fundamental aspects of heterogeneous reduction schemes in iron ore sinter.

  4. Complex sulphide-barite ore leaching in ferric chloride solution

    Miroslav Sokić


    Full Text Available The results of research on the leaching process of complex sulphide-barite ore were presented in this paper. The leaching process was carried out in a laboratory autoclave by ferric chloride solution. Considering that those minerals are represented in complex structural-textural relationships, it is not possible to extract lead, zinc and copper minerals from ore by flotation methods. The obtained results confirmed possibility of the ore processing directly, by chemical methods. The effect of temperature, time and oxygen partial pressure on the lead, zinc and copper dissolution was studied. The maximal leaching degree was achieved at 100 °C and amount of 91.5 % for Pb, 96.1 % for Zn and 60.7 % for Cu. Leaching at temperatures above 100 °C is impractical.

  5. A hybrid decision support system for iron ore supply

    A. Samolejová


    Full Text Available Many European metallurgical companies are forced to import iron ore from remote destinations. For these companies it is necessary to determine the amount of iron ore that will have to be ordered and to create such a delivery schedule so that the continuous operation of blast-furnace plant is not disrupted and there is no exceedingly large stock of this raw material. The objective of this article is to design the decision support system for iron ore supply which would effi ciently reduce uncertainty and risk of that decision-making. The article proposes a hybrid intelligent system which represents a combination of diff erent artifi cial intelligence methods with dynamic simulation technique for that purpose.

  6. Treatment of coking wastewater by using manganese and magnesium ores.

    Chen, Tianhu; Huang, Xiaoming; Pan, Min; Jin, Song; Peng, Suchuan; Fallgren, Paul H


    This study investigated a wastewater treatment technique based on natural minerals. A two-step process using manganese (Mn) and magnesium (Mg) containing ores were tested to remove typical contaminants from coking wastewater. Under acidic conditions, a reactor packed with Mn ore demonstrated strong oxidizing capability and destroyed volatile phenols, chemical oxygen demand (COD)(,) and sulfide from the coking wastewater. The effluent was further treated by using Mg ore to remove ammonium-nitrogen and phosphate in the form of magnesium ammonium phosphate (struvite) precipitates. When pH of the wastewater was adjusted to 1.2, the removal efficiencies for COD, volatile phenol and sulfide reached 70%, 99% and 100%, respectively. During the second step of precipitation, up to 94% of ammonium was removed from the aqueous phase, and precipitated in the form of struvite with phosphorus. The struvite crystals showed a needle-like structure. X-ray diffraction and transmission electron microscopy were used to characterize the crystallized products.

  7. Investigation of chemical suppressants for inactivation of sulfide ores


    In order to investigate the effective control method of spontaneous combustion in the mining of sulfide ore deposits, This paper presents the testing results of several selected chemicals (water glass, calcium chloride, calcium oxide, magnesium oxide and their composites) as oxidation suppressants for sulfide ores. A weight increment scaling method was used to measure suppressant performance, and this method proved to be accurate, simple and convenient. Based on a large number of experiments, the test results show that four types of chemical mixtures demonstrate a good performance in reducing the oxidation rate of seven active sulfide ore samples by up to 27% to 100% during an initial 76 d period. The mixtures of water glass mixed with calcium chloride and magnesium oxide mixed with calcium chloride can also act as fire suppressants when used with fire sprinkling systems.

  8. Calcination-Digestion-Desliming of Phosphorus Ore Bearing Rare Earth

    Zhang Qin; Zhang Jie; Wang Jing; Qiu Yue qin


    The recoveries of phosphorus and RE of ore from Zhijin in Guizhou were studied.The influences of the calcination temperature, resident time, the digested time and water volume of the calcinating on concentrate yield by desliming were also investigated by orthogonal design.Appropriate calcination temperature is initial condition that makes carbonate mineral decomposition.The recovery of phosphorus is 83.02% and rare earth is 90.56% in phosphorus concentrate when calcined temperature is 900 ℃, other conditions include: calcined time is 30 min, digestion water volume is 300 ml, digestion time is 20 min.The results show that the pre-treatment of the ore is favorable for the separation and enrichment of rare earth from phosphorus ore, and a process of calcination-digestion-desliming was promised.

  9. Fossil bacteria in Xuanlong iron ore deposits of Hebei Province

    DAI Yongding; SONG Haiming; SHEN Jiying


    Discovered in Early Proterozoic Xuanlong iron ore deposits are six genera of fossil iron bacteria, i. e. sphere (coenobium of) rod-shaped (monomer) Naumanniella, ellipsoid elliptical Ochrobium, sphere spherical Siderocapsa and chain spherical Siderococcus, chain rod-shaped Leptothrix and Lieskeella, and six genera of fossil blue bacteria, namely sphere spherical Gloeocapsa, Synechocystis and Globobacter, chain spherical Anabaena and Nostoc, and constrictive septate tubular Nodularia. The biomineralized monomers and coenobia of the two categories of bacteria, together with hematite plates made up the bacteria pelletal, bacteria silky,bacteria fibrous and clasty bacteria pelletal textural lamina. The bacteria pelletal laminae combined with other bacteria laminae to make up oncolite, stromatolite and laminate. The precipitation of iron oxide was accelerated due to iron and blue bacteria cohabiting on microbial film or mat. The Xuanlong iron ore deposits are microbial binding ore deposits of ocean source.

  10. Novel Binders and Methods for Agglomeration of Ore

    S. K. Kawatra; T. C. Eisele; K. A. Lewandowski; J. A. Gurtler


    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. Primary examples of this are copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process, and advanced ironmaking processes, where binders must function satisfactorily over an extraordinarily large range of temperatures (from room temperature up to over 1200 C). As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching and advanced primary ironmaking. This project has identified several acid-resistant binders and agglomeration procedures that can be used for improving the energy efficiency of heap leaching, by preventing the ''ponding'' and ''channeling'' effects that currently cause reduced recovery and extended leaching cycle times. Methods have also been developed for iron ore

  11. Control of Rock Mechanics in Underground Ore Mining

    Golik, V. I.; Efremenkov, A. B.


    Performance indicators in underground mining of thick iron fields can be insufficient since geo-mechanic specifics of ore-hosting fields might be considered inadequately, as a consequence, critical deformations and even earth’s surface destruction are possible, lowering the indicators of full subsurface use, this way. The reason for it is the available approach to estimating the performance of mining according to ore excavation costs, without assessing losses of valuable components and damage to the environment. The experimental approach to the problem is based on a combination of methods to justify technical capability and performance of mining technology improvement with regard to geomechanical factors. The main idea of decisions to be taken is turning geo-materials into the condition of triaxial compression via developing the support constructions of blocked up structural rock block. The study was carried out according to an integrated approach based on the analysis of concepts, field observations, and simulation with the photo-elastic materials in conditions of North Caucasus deposits. A database containing information on the deposit can be developed with the help of industrial experiments and performance indicators of the field can be also improved using the ability of ore-hosting fields to develop support constructions, keeping the geo-mechanical stability of the system at lower cost, avoiding ore contamination at the processing stage. The proposed model is a specific one because an adjustment coefficient of natural and anthropogenic stresses is used and can be adopted for local conditions. The relation of natural to anthropogenic factors can make more precise the standards of developed, prepared and ready to excavation ore reserves relying on computational methods. It is possible to minimize critical stresses and corresponding deformations due to dividing the ore field into sectors safe from the standpoint of geo-mechanics, and using less cost

  12. Isolation and identification of iron ore-solubilising fungus

    Damase Khasa


    Full Text Available Potential mineral-solubilising fungi were successfully isolated from the surfaces of iron ore minerals. Four isolates were obtained and identified by molecular and phylogenetic methods as close relatives of three different genera, namely Penicillium (for isolate FO, Alternaria (for isolates SFC2 and KFC1 and Epicoccum (for isolate SFC2B. The use of tricalcium phosphate (Ca3(PO42in phosphate-solubilising experiments confirmed isolate FO as the only phosphate solubiliser among the isolated fungi. The bioleaching capabilities of both the fungus and its spent liquid medium were tested and compared using two types of iron ore materials, conglomerate and shale, from the Sishen Iron Ore Mine as sources of potassium (K and phosphorus (P. The spent liquid medium removed more K (a maximum of 32.94% removal, from conglomerate, than the fungus (a maximum of 21.36% removal, from shale. However, the fungus removed more P (a maximum of 58.33% removal, from conglomerate than the spent liquid medium (a maximum of 29.25% removal, from conglomerate. The results also indicated a potential relationship between the removal of K or P and the production of organic acids by the fungus. A high production of gluconic acid could be related to the ability of the fungus to reduce K and P. Acetic, citric and maleic acids were also produced by the fungus, but in lower quantities. In addition, particle size and iron ore type were also shown to have significant effects on the removal of potassium and phosphorus from the iron ore minerals. We therefore conclude that the spent liquid medium from the fungal isolate FO can potentially be used for biobeneficiation of iron ore minerals.

  13. Novel Binders and Methods for Agglomeration of Ore

    S. K. Kawatra; T. C. Eisele; K. A. Lewandowski; J. A. Gurtler


    Many metal extraction operations, such as leaching of copper, leaching of precious metals, and reduction of metal oxides to metal in high-temperature furnaces, require agglomeration of ore to ensure that reactive liquids or gases are evenly distributed throughout the ore being processed. Agglomeration of ore into coarse, porous masses achieves this even distribution of fluids by preventing fine particles from migrating and clogging the spaces and channels between the larger ore particles. Binders are critically necessary to produce agglomerates that will not break down during processing. However, for many important metal extraction processes there are no binders known that will work satisfactorily. Primary examples of this are copper heap leaching, where there are no binders that will work in the acidic environment encountered in this process, and advanced ironmaking processes, where binders must function satisfactorily over an extraordinarily large range of temperatures (from room temperature up to over 1200 C). As a result, operators of many facilities see a large loss of process efficiency due to their inability to take advantage of agglomeration. The large quantities of ore that must be handled in metal extraction processes also means that the binder must be inexpensive and useful at low dosages to be economical. The acid-resistant binders and agglomeration procedures developed in this project will also be adapted for use in improving the energy efficiency and performance of a broad range of mineral agglomeration applications, particularly heap leaching and advanced primary ironmaking. This project has identified several acid-resistant binders and agglomeration procedures that can be used for improving the energy efficiency of heap leaching, by preventing the ''ponding'' and ''channeling'' effects that currently cause reduced recovery and extended leaching cycle times. Methods have also been developed for iron ore

  14. [Assessment of Soil Fluorine Pollution in Jinhua Fluorite Ore Areas].

    Ye, Qun-feng; Zhou, Xiao-ling


    The contents of. soil total fluorine (TF) and water-soluble fluorine (WF) were measured in fluorite ore areas located in Jinhua City. The single factor index, geoaccumulation index and health risk assessment were used to evaluate fluorine pollution in soil in four fluorite ore areas and one non-ore area, respectively. The results showed that the TF contents in soils were 28. 36-56 052. 39 with an arithmetic mean value of 8 325.90, a geometric mean of 1 555. 94, and a median of 812. 98 The variation coefficient of TF was 172. 07% . The soil WF contents ranged from 0. 83 to 74. 63 with an arithmetic mean value of 16. 94, a geometric mean of 10. 59, and a median of 10. 17 The variation coefficient of WF was 100. 10%. The soil TF and WF contents were far higher than the national average level of the local fluorine epidemic occurrence area. The fluoride pollution in soil was significantly affected by human factors. Soil fluorine pollution in Yangjia, Lengshuikeng and Huajie fluorite ore areas was the most serious, followed by Daren fluorite ore area, and in non-ore area there was almost no fluorine pollution. Oral ingestion of soils was the main exposure route. Sensitivity analysis of model parameters showed that children's weight exerted the largest influence over hazard quotient. Furthermore, a significant positive correlation was found among the three kinds of evaluation methods.

  15. Challenges facing the North American iron ore industry

    Jorgenson, J.D.


    During the 20th century, the iron ore mining industries of Canada and the United States passed through several periods of transformation. The beginning of the 21st century has seen yet another period of transformation, with the economic failure of a number of steel companies, the acquisition of their facilities by more viable steelmakers, and the consolidation of control within the North American iron ore industry. Changes in Canadian and United States iron ore production and the market control structure involved are analysed. The consolidation of ownership, formation of foreign joint ventures within Nordi America, planned divestitures of upstream activities by steelmakers, and industry changes made to ensure availability of feedstocks will be reviewed. The ttaditional isolation of the Canadian and United States iron ore operations and their strong linkage to downstream steel production will be discussed in the context of a changing global economy. Management-labour conflicts that have taken place and agreements made during 2000 through 2004 will be discussed in the context of the economic environment leading up to these agreements. Cooperative agreements between competing Canadian and United States companies to resolve client needs in processing and blending will be examined. A joint industry-government project designed to use new technology to produce direct reduced iron nuggets of 96 - 98 per cent iron content using non-coking coals will also be assessed. Changes in iron ore transportation methods, ownership and infrastructure will be reviewed for both rail and inland waterway transport between Canadian and United States companies. A brief analysis of social and environmental issues relating to sustainable development of the Canadian-United States iron ore industry will be included.

  16. Stratigraphy and mineralogy of a carbonate-hosted gold deposit: Kings Mountain gold mine, NC

    Supplee, J.; Lapoint, D.; Feiss, P.G.


    The Kings Mountain Gold Mine, Cleveland Company, North Carolina, is unique in the Appalachians in that it is carbonate-hosted, with a distinctive ore mineralogy. The mine stratigraphy is upright, younging east to west. The basal unit is a volcanic to subvolcanic chlorite, feldspar, quartz-eye porphyry, cut by a silicic porphyry, interpreted as a shallow level intrusion. Above and gradational to the chloritic porphyry, unless separated by the intrusive silicic porphyry, is a sericitic, quartz-eye porphyry, probably a metatuff. A north-thinning, graphite schists is above the sericitic porphyry. Carbonates overlie the graphite schist except to the north where they are above the sericitic porphyry. The carbonates consist of basal and upper sequences separated by a sericite, quartz-eye schists (metatuff) which is capped by a chlorite-sericite-graphite schist. Mineralization occurs within each carbonate sequence. This is overlain by interbedded chlorite and graphite schists with two horizons of exhalative iron formation (I.F.). Above the I.F. is a thick sequence of sericitic chlorite schists (turbidites). The mineralized carbonates are pervasively silicified with a disseminated assemblage of pyrite, pyrrhotite, sphalerite, chalcopyrite, galena, gold, altaite (PbTe), tetrahedrite, and pyrargyrite in quartz and dolomite +/- fluorite gangue. We suggest that the mineralization is associated with hydrothermal activity during emplacement of the silicic porphyry and following carbonate diagenesis. Mineralization was syn- or post-depositional with respect to the I.F.

  17. Ore-forming Conditions and Prospecting in the West Kunlun Area, Xinjiang, China

    DONG Yongguan; GUO Kunyi; XIAO Huiliang; ZHANG Chuanlin; ZHAO Yu


    The West Kunlun ore-forming belt is located between the northwestern Qinghai-Tibet Plateau and southwestern Tarim Basin. It situated between the Paleo-Asian Tectonic Domain and Tethyan Tectonic Domain. It is an important component of the giant tectonic belt in central China (the Kunlun-Qilian-Qinling Tectonic Belt or the Central Orogenic Belt). Many known ore-forming belts such as the Kunlun-Qilian Qinling ore-forming zone, Sanjiang (or Threeriver) ore-forming zone, Central Asian ore-forming zone, etc. pass through the West Kunlun area. Three ore-forming zones and seven ore-forming subzones were classified, and eighteen mineralization areas were marked. It is indicated that the West Kunlun area is one of the most favorable region for finding out large and superlarge ore deposits.

  18. A study of the distribution of rare-metals in kuroko-type ore

    Murao, S. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience]|[Geological Survey of Japan, Tsukuba, Ibaraki (Japan); Sie, S.H.; Suter, G.F. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience


    We have performed PIXE analysis of kuroko-type ore from the JADE hydrothermal site of the Okinawa Trough, Japan using the proton microprobe (PIXEPROBE). We analysed five kinds of ores dredged from the sea floor: (I) barite ore with small sulfide dissemination; (2) sphalerite-pyrite chimney; (3) pyrite ore; (4) sulfide veinlets in strongly altered rock; and (5) pyrite megacrystals in strongly altered rock. The analyses revealed that the trace element distribution is regulated by the occurrence mode of the ore, and within each ore, by the crystal structure. The distribution suggests that the hydrothermal system for kuroko ore formation is quite heterogeneous and its chemistry is controlled by local factors such as difference in temperature, and that in-situ PIXE analyses are essential for effective beneficiation strategy for the rare-metals from kuroko-type ore. (authors). 10 refs., 1 tab.

  19. Multistage gold mineralization in the Wa-Lawra greenstone belt, NW Ghana: The Bepkong deposit

    Amponsah, Prince Ofori; Salvi, Stefano; Didier, Béziat; Baratoux, Lenka; Siebenaller, Luc; Jessell, Mark; Nude, Prosper Mackenzie; Gyawu, Eugene Adubofour


    The Bepkong gold deposit is one of several gold camps in the Paleoproterozoic Wa-Lawra greenstone belt in northwest Ghana. These deposits lay along the Kunche-Atikpi shear zone, which is part of the larger transcurrent Jirapa shear zone. The formation of these shear zones can be attributed to the general ESE-WNW major shortening that took place in the Wa-Lawra belt. Gold mineralization in the Bepkong deposit mainly occurs within graphitic shales and volcaniclastic rocks. The ore consists of four N-S trending lenticular bodies, plunging steeply to the south, that are lithologically and structurally controlled. Their shape and thickness are variable, though a general strike length of 560 m and an overall thickness of 300 m can be defined. An alteration mineral assemblage characterises the ore, and consists of chlorite-calcite-sericite-quartz-arsenopyrite-pyrite. Pyrite, as distinct from arsenopyrite, is not limited to the altered rocks and occurs throughout the area. At Bepkong, gold is associated with arsenopyrite and pyrite, which occur disseminated in the mineralized wall rock, flanking Type-1 quartz veins, or within fractures crossing these veins. Textural observations indicate the early formation of abundant arsenopyrite, followed by pyrite, with chalcopyrite, galena, sphalerite and pyrrhotite occurring as inclusions within pyrite and altered arsenopyrite. Detailed petrography, coupled with SEM, LA-ICP-MS and EMP analyses, indicate that gold in the Bepkong deposit occurs in three distinct forms: (i) invisible gold, mostly in arsenopyrite (ii); visible gold as micron-size grains within fractures and altered rims of arsenopyrite, as well as at the interface of sulphide grains; (iii) free visible gold in fractures in quartz veins and their selvages. We interpret the invisible gold to have co-precipitated with the early-formed arsenopyrite. The small visible gold grains observed within the sulphide interfaces, altered arsenopyrite, fractures and grain boundaries

  20. Mining remittances corresponding to metalliferous ores: regulation and budget impact

    N. Asaloș


    Full Text Available Economic statistics and forecasting show that Romania has a very favourable potential as far as the metalliferous ores are concerned. As these are owned by the state, once they are allowed to be exploited, they generate considerable amounts for the consolidated public budget. The present paper is meant to conduct a synthetic analysis on the topic of mining remittances from an economic perspective, by considering the juridical framework of capitalizing deposits of ferrous and non-ferrous ores, correlated with the general regulations concerning property and the specific existing regulations of the EU and of the countries that have experience and potential in the mining sector.

  1. Bioleaching of copper oxide ore by Pseudomonas aeruginosa

    Shabani, M. A.; Irannajad, M.; Azadmehr, A. R.; Meshkini, M.


    Bioleaching is an environmentally friendly method for extraction of metal from ores. In this study, bioleaching of copper oxide ore by Pseudomonas aeruginosa was investigated. Pseudomonas aeruginosa is a heterotrophic bacterium that can produce various organic acids in an appropriate culture medium, and these acids can operate as leaching agents. The parameters, such as particle size, glucose percentage in the culture medium, bioleaching time, and solid/liquid ratio were optimized. Optimum bioleaching conditions were found as follows: particle size of 150-177 μm, glucose percentage of 6%, bioleaching time of 8 d, and solid/liquid ratio of 1:80. Under these conditions, 53% of copper was extracted.

  2. A novel optical granulometry algorithm for ore particles

    Junhao Y.


    Full Text Available This paper proposes a novel algorithm to detect the particle size distribution of ores with irregular shapes and dim edges. This optical granulometry algorithm is particularly suitable for blast furnace process control, so its result can be used directly as a reliable basis for control system dynamics optimization. The paper explains the algorithm and its concept, as well as its method, which consists of five steps to detect ore granularity and distribution. A series of comparative experiments under industrial environments proved that this novel algorithm, compared with conventional ones, improves the accuracy of granulometry.

  3. Bioleaching of copper oxide ore by P seudomonas aeruginosa

    MA Shabani; M Irannajad; AR Azadmehr; M Meshkini


    Bioleaching is an environmentally friendly method for extraction of metal from ores. In this study, bioleaching of copper oxide ore by Pseudomonas aeruginosa was investigated. Pseudomonas aeruginosa is a heterotrophic bacterium that can produce various organic acids in an appropriate culture medium, and these acids can operate as leaching agents. The parameters, such as particle size, glucose percentage in the culture medium, bioleaching time, and solid/liquid ratio were optimized. Optimum bioleaching conditions were found as follows: particle size of 150-177 μm, glucose percentage of 6%, bioleaching time of 8 d, and solid/liquid ratio of 1:80. Under these conditions, 53%of copper was extracted.

  4. Gold cementation on copper in thiosulfate solution: Kinetic, electrochemical, and morphological studies

    Lee, Jaeheon


    Cyanidation has been used for more than a century for precious metal recovery and it is still in use today. Cyanide is a very toxic chemical and if not used appropriately will cause environmental problems. There is considerable attention devoted to the development of non-cyanide lixiviants for the process of gold and silver ores. Thiosulfate solution is one of the proposed alternatives to cyanide and gold cementation by copper has been suggested as a promising method for gold recovery from leaching solution. Copper powder and rotating disc electrode were used for the kinetic study. The rate of gold cementation on copper disc is proportional to the initial gold concentration and disc rotating speed. The cementation reaction exhibited two distinct kinetic regions, an initial slow rate followed by an enhanced rate. The activation energy of the reaction was 5.9 kJ/mol at low copper concentration and the reaction is mass transport controlled. With 30 ppm initial copper concentration, there was noticeable decrease in the reaction rate in high temperature range. EDS, XRD, and XPS analysis revealed that the deposits are a Au-Cu alloy instead of pure gold. The alloy composition ranged from Au 3Cu to AuCu3 depending on the initial Cu/Au mole ratio in solution and applied potential. Electrochemical studies were performed using rotating disc electrode and electrochemical quartz crystal nanobalance. Evans' diagrams were constructed under various experimental conditions. Corrosion current increased with increasing gold concentration, disc rotating speed, as well as thiosulfate concentration. These results confirmed those obtained in the kinetic study. Corrosion potential measurements indicated that passivation onset time was changed by gold concentration, copper concentration and disc rotating speed. Gold(I)-thiosulfate reduction was found to occur at approximately -250 mV vs. SHE using EQCN. Copper adions on the gold surface contributed to the underpotential deposition of

  5. Prelude to Gold


    FEMALE Chinese athletes Fu Mingxia and Wang Junxia recorded outstanding performances at 1996 Atlanta Olympic Games. Fu Mingxia won gold medals in both platform and springboard diving, and in so doing became the first double medal winner in Olympic diving since 1960. Wang Junxia, the holder of several world records in women’s long distance events, struggled against the odds and captured gold in the 5,000-meter event,

  6. Gold nanoprobes for theranostics

    Panchapakesan, Balaji; Book-Newell, Brittany; Sethu, Palaniappan; Rao, Madhusudhana; Irudayaraj, Joseph


    Gold nanoprobes have become attractive diagnostic and therapeutic agents in medicine and life sciences research owing to their reproducible synthesis with atomic level precision, unique physical and chemical properties, versatility of their morphologies, flexibility in functionalization, ease of targeting, efficiency in drug delivery and opportunities for multimodal therapy. This review highlights some of the recent advances and the potential for gold nanoprobes in theranostics. PMID:22122586

  7. The Gold Standard Programme

    Neumann, Tim; Rasmussen, Mette; Ghith, Nermin


    To evaluate the real-life effect of an evidence-based Gold Standard Programme (GSP) for smoking cessation interventions in disadvantaged patients and to identify modifiable factors that consistently produce the highest abstinence rates.......To evaluate the real-life effect of an evidence-based Gold Standard Programme (GSP) for smoking cessation interventions in disadvantaged patients and to identify modifiable factors that consistently produce the highest abstinence rates....

  8. Joining the Gold Rush

    LIU BO


    @@ Flush with advanced technology and large amounts of capital, overseas mining firms are carving a place in the Chinese gold industry Dozens of Western mining companies, particularly those from Canada, are making the journey into the kind of remote corners in China that other overseas investors shy away from. What are they looking for? The answer is one of the most precious substances on the planet: gold.

  9. Environmental nuclear-geophysical ore monitoring in mines of Corporation Kazakhmys PLC.

    Yefimenko, Sergei; Yefimenko, Olga; Makarov, Dmitriy


    An environmental monitoring of ore composition in complex deposits of Kazakhstan (the Zhezkazgan, Kusmuryn, Artemjevsk, Kounrad, Taskura and Zhaman-Aibat deposits) is carried out using EDXRF spectrometers RPP-12, RLP-21 and RLP-21T. The monitoring of ore concentrates in Satpaev, Balkhashsk and Zhezkazgan processing plants and in Zhezkazgan copper smelter continues at present time. The monitoring suggests data on new promising elements and environmental pollutants in ores and new trends in distribution of bound elements in ores.

  10. Sediment—Hosted Gold Deposits in China_geochemistry and Prospecting

    杨蔚华; 刘友梅


    Sediment-hosted gold deposits are the major type of gold resources in china,Concen trated mostly in the two"Triangle Regios",they are generally hosted in fine-clastic turbidite,hydrothermal chet and marl ranging from cambrian to Triassic in age,structurally controlled by domes,anticlines and second-ordered faults.They are similar to the Carlin-type gold deposits in mineral assemblage and geochemical marks,with an element association closely comparable to those of modern springs and submarine hydrothermal sediments.Organic matter may have played an important role in mineralization .The ore solution may be hydrothermally altered meteoric water developed i areas of local geothermal anomaly.

  11. Genesis and Geological—Geochemical Characters of the ushan Gold Deposit,Shandong,China

    翟建平; 胡凯; 等


    The Rushan gold deposit,explored in recent years in the Jiaodong area,Shandong Provinces,is a quartz vein-type gold deposit hosted in granite.The temperature of its major mineralization episode is between 220℃ and 280℃.The salinity o the ore-forming fluid is 5% to 9% NaCl equivalent,with H2O and CO2 as he dominant gas constituents.The fluid is rich in Na+,Ca2+ and Cl-,but relatively impoverished in K+ and F-,characterized by either Ca2+>Na+>K+(in three samples)or Na+>Ca+>K+(in six samples).Hydrogen and oxygen isotopes in the ore-forming fluid are highyly variable with δ18OH2o ranging between-7.70‰and 5.97‰andδDH2 o between-128‰and-71‰.The possiblity of lamprophyre serving as the source of gold can be excluded in view of its low gold content on the order of 2.5×10-9,Rb-S isochron ages of the deposit and the host Kunyushan granite are(104.8±1.5)Ma and 134.6Ma respectively with the respective initial Sr ratios of 0.71307 and 0.7096.It is considered that the emplacement of the labprophyre under a tensile environment had provided sufficient heat energy to facilitate deep circulation of meteoric water by which ore metals were extracted from the Kunyushan granite through long-term water-rock reaction.

  12. 26 CFR 1.272-1 - Expenditures relating to disposal of coal or domestic iron ore.


    ... domestic iron ore. 1.272-1 Section 1.272-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE... relating to disposal of coal or domestic iron ore. (a) Introduction. Section 272 provides special treatment... sometimes referred to as a “coal royalty contract” or “iron ore royalty contract”) for the disposal of coal...

  13. 75 FR 68788 - Ore Knob Mine Superfund Site; Jefferson, Ashe County, North Carolina; Notice of Settlement


    ... Doc No: 2010-28260] ENVIRONMENTAL PROTECTION AGENCY [Docket EPA-RO4-SFUND-2010-0893, FRL-9223-8] Ore... Protection Agency has entered into a settlement for reimbursement of past response costs concerning the Ore..., identified by Docket ID No. EPA-RO4- SFUND-2010-0893 or Site name Ore Knob Mine Superfund Site by one of...

  14. IMPACT: How ORE Findings Have Affected Decisions in Austin and Beyond.

    Wilkinson, David, Ed.; Ligon, Glynn, Ed.

    Over the years, findings of the Office of Research and Evaluation (ORE) of the Austin (Texas) Independent School District (AISD) have had a significant impact on decisions made in the district and sometimes beyond it. The ORE's impact in the AISD is reviewed in 16 areas. Some of the major findings are summarized: (1) ORE studies of retention in…

  15. 40 CFR 440.80 - Applicability; description of the vanadium ore subcategory.


    ... vanadium ore subcategory. 440.80 Section 440.80 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Vanadium Ore Subcategory (Mined Alone and Not as a Byproduct) § 440.80 Applicability; description of the vanadium...

  16. 28 CFR 79.62 - Criteria for eligibility for claims by ore transporters.


    ... ore transporters. 79.62 Section 79.62 Judicial Administration DEPARTMENT OF JUSTICE (CONTINUED) CLAIMS UNDER THE RADIATION EXPOSURE COMPENSATION ACT Eligibility Criteria for Claims by Ore Transporters § 79.62 Criteria for eligibility for claims by ore transporters. To establish eligibility for...

  17. 28 CFR 79.63 - Proof of employment as an ore transporter.


    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Proof of employment as an ore transporter... RADIATION EXPOSURE COMPENSATION ACT Eligibility Criteria for Claims by Ore Transporters § 79.63 Proof of employment as an ore transporter. (a) The Department will accept, as proof of employment for the time...

  18. Rock-magnetism and ore microscopy of the magnetite-apatite ore deposit from Cerro de Mercado, Mexico

    Alva-Valdivia, L. M.; Goguitchaichvili, A.; Urrutia-Fucugauchi, J.; Caballero-Miranda, C.; Vivallo, W.


    Rock-magnetic and microscopic studies of the iron ores and associated igneous rocks in the Cerro de Mercado, Mexico, were carried out to determine the magnetic mineralogy and origin of natural remanent magnetization (NRM), related to the thermo-chemical processes due to hydrothermalism. Chemical remanent magnetization (CRM) seems to be present in most of investigated ore and wall rock samples, replacing completely or partially an original thermoremanent magnetization (TRM). Magnetite (or Ti-poor titanomagnetite) and hematite are commonly found in the ores. Although hematite may carry a stable CRM, no secondary components are detected above 580°, which probably attests that oxidation occurred soon enough after the extrusion and cooling of the ore-bearing magma. NRM polarities for most of the studied units are reverse. There is some scatter in the cleaned remanence directions of the ores, which may result from physical movement of the ores during faulting or mining, or from perturbation of the ambient field during remanence acquisition by inhomogeneous internal fields within these strongly magnetic ore deposits. The microscopy study under reflected light shows that the magnetic carriers are mainly titanomagnetite, with significant amounts of ilmenite-hematite minerals, and goethite-limonite resulting from alteration processes. Magmatic titanomagnetites, which are found in igneous rocks, show trellis, sandwich, and composite textures, which are compatible with high temperature (deuteric) oxy-exsolution processes. Hydrothermal alteration in ore deposits is mainly indicated by martitization in oxide minerals. Grain sizes range from a few microns to >100 mm, and possible magnetic state from single to multidomain, in agreement with hysteresis measurements. Thermal spectra, continuous susceptibility measurements, and IRM (isothermal remanent magnetization) acquisition suggest a predominance of spinels as magnetic carriers, most probably titanomagnetites with low

  19. High and Low Temperature Gold Mineralizations in the Fe–Cu–Zn Sulfide Deposits of Corchia Ophiolite, Northern Italian Apennine

    Zaccarini Federica


    Full Text Available Gold has been found in the Cyprus-type volcanogenic massive sulfide ore (VMS deposits of Corchia ophiolite (Parma province, Italy in the Cantiere Donnini, Speranza and Pozzo mining sites. At Cantiere Donnini and Speranza, the mineralization occurs at the contact between pillow lava and sedimentary rocks. The Pozzo mineralization is hosted by a serpentinite. Concentrations of gold up to 3070 ppb have been reported for the Cantiere Donnini and up to 6295 ppb in the Pozzo mine. According to the field relationships, gold composition, mineralogical assemblage and sulfur isotope data, we can conclude that two different types of gold mineralization have been recognized in the Corchia ophiolite: (1 formed at low temperature in submarine environment (Cantiere Donnini and Speranza and (2 formed at high temperature in the oceanic mantle (Pozzo by segregation of an immiscible sulfide liquid.

  20. [Selection of a community of acidochemolithotrophic microorganisms with a high oxidation rate of pyrrhotite- containing sulphide ore flotatation concentrate].

    Kondrat'eva, T F; Pivovarova, T A; Bulaev, A G; Moshchanetskiĭ, P V; Tsaplina, I A; Grigor'eva, N V; Zhuravleva, A E; Melamud, V S; Belyĭ, A V


    A community of acidochemolithotrophic microorganisms with a high oxidation rate of pyrrhotite-containing sulphide ore flotation concentrate was selected. The Acidithiobacillus caldus OP-1 and Ferroplasma acidiphilum OP-2 cultures were identified to be dominating members. The presence of the Acidithio- bacillusferrooxidans OP-3, Leptospirillumferriphilum OP-4, and Sulfobacillus thermosulfidooxidans OP-5 cultures in the community's composition was also mentioned. The analysis results of solid residues of the process showed a greater elemental sulfur oxidation level and gold recovery when the initial pH value in tank I was maintained at a level of 1.8-2.0 (90.5%) rather than 1.6-1.8 (86.3%).