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Liu Y.,China University of Geosciences | Yang L.,China University of Geosciences | Guo L.,China Railway Resources Exploration Co. | Li R.,China University of Geosciences | And 4 more authors.
Acta Petrologica Sinica | Year: 2014

The Dayingezhuang gold deposit, located in the central section of the Zhaoping Fault Zone, northwestern Jiaodong Peninsula, within the phyllic zone in the footwall of main fault. Wall-rock alteration is intense and has a variety of types that include potash feldspathization, silication, sericitization, pyritization, chloritization and carbonatation. Amongst these alterations, silication, sericitization and pyritization are considered more closely related with the gold mineralization. Based on the cutting relations of veins and paragenesis of ore minerals, we determined three major mineralization stages: gold-quartz-pyrite, gold (silver) -quartz-polymetallic sulfides, quartz-calcite-pyrite. Employing the decrepitation thermometry to the ore quartz, we identified three concentrated ranges: 330-510°C, 240-330°C and 240-330°C, which are corresponding with each of the mineralization stage above. The ore-forming fluids in the Dayingezhuang gold deposit are characterized by medium temperature and rich in CO2content, contain a small amount of volatile gases, such as CH4, C2H6and H2S. The scheme of NaCl-H2O-CO2and the high level content of C2H6existed in all of mineralization stages indicate that the ore-forming fluids mostly are the metamorphic water. Even though the gas-liquid content from different mineralization stages are similar with each other, we still observed certain rules along the ore-forming evolution. The trend of increasing N2content indicates that the ore-forming fluids system switch to an open system in the late stage, and atmospheric water began to take part in the ore-forming fluids. The high quantity of H2S in the early gold mineralization indicates that the gold possibly was migrated as Au-S complex. The climbing ratios of C1-/SO2- 4and Na+/K+show that the ore-forming system convert from the CO2-H2O-K2SO4into CO2-H2O-NaCl system with the evolving process. The concentration of Na+, C1-, K+and SO2- 4decreased from early stage to later stage indicates that the salinity of ore-fluid declined. The higher ratio of H2O/CO2in the later stage represents that the fluid boiling may occurred in the middle stage. Overall, we think that a variety of fluid processes, including change of fluid inclusion types and fluid boiling, have been suggested for gold precipitation.

Zhang L.,China University of Geosciences | Liu Y.,China University of Geosciences | Li R.,China University of Geosciences | Huang T.,China University of Geosciences | And 4 more authors.
Acta Petrologica Sinica | Year: 2014

The gold deposits of the Jiaodong Peninsula define the China's largest gold province. Disseminated- and stockwork-style gold deposit, which accounts for 90% of the proved reserves in Jiaodong Peninsula, is the most important deposit type. Its giant source of gold is a striking and key scientific issue. Zhaoping fault zone, whose proved reserves exceed 1500t Au, is the largest fault-metallogenic belt in Jiaodong Peninsula. Dayingezhuang gold deposit, a typical disseminated- and stockwork-style gold deposit, whose proved reserves are about 125t Au, located in the central part of Zhaoping metallogenic belt. Its exploration depth is nearly-800m. NNE-trending Zhaoping fault and NNW-trending Dayingezhuang fault are the main ore-controlling structures. The Zhaoping fault develops along the contacts between the Jiaodong Group and Linglong granite and controls the occurrence of the gold orebodies in Dayingezhuang gold deposit. Linglong granite locates in the footwall of Zhaoping fault. Generally, it underwent pyrite-sericite-quartz alteration and hosts most part of the gold orebodies. Wall rocks in the hanging wall, which underwent intensive carbonation, comprise migmatization biotite-plagioclase-granulite, carbonate schist and amphibolite of Archaean Jiaodong Group, and garnet-sillimanite-biotite schist and biotite schist in the Lugezhuang Formation of Paleoproterozoic Jingshan Group. The gold mineralization is closely related to sericitization, pyritization and silication. The gold orebodies are located in the pyrite-sericite-quartz altered rock and pyrite-sericite-quartz altered cataclasite in footwall of Zhaoping fault. The main metallic mineral is pyrite, followed by galena, sphalerite and chalcopyrite. Frequently, pyrite is symbiotic with galena and sphalerite. The No. I and II orebodies, located in the south and north of the Dayingezhuang Fault respectively, account for 85% of the proved reserves in Dayingezhuang gold deposit. Comparing with the No. II orebody, the No. I orebody possesses more galena, sphalerite and higher silver grades. Nine sulfide samples selected from ores of No. I orebody yield 206Pb/204Pb, 207Pb/204Pb, 208Pb/204Pb of 17. 2638 ∼ 17. 3585, 15.4663 ∼ 15. 6116 and 37. 858-38. 3328 respectively. Six sulfide samples selected from ores of No. II orebody yield 206Pb/204Pb, 207Pb/204Pb, 208Pb/204Pb of 17.2157 ∼ 17. 3286, 15.4595 ∼ 15. 5084 and 37. 8900 ∼ 38. 0004 respectively. They are radiogenic and anomalous lead, who underwent three stages of evolution. The crust-mantle differentiation occurred at about 3.4 Ga when the Pb isotope between the lower crust and upper mantle mixed and formed the normal lead. At about 0.8 Ga, the lead escaped from the reservoirs of the second stage. Then it mixed with a certain amount of radiogenic lead. Finally, it was trapped in the gold-bearing sulfide at ca. 130Ma. All these reveal that ore-forming material may mainly be derived from the Mesozoic remobilization of metamorphic rock of the Jiaodong Group. The No. I orebody underwent intensive water-rock reaction accompanied by the mixing of more substance of the upper crust, when the gold deposited from the ore-forming fluids in the brittle faults of upper crust. In contrast, the No. II orebody keeps more information about the initial ore-forming materials and fluids.

Sun H.-S.,Wuhan University | Wu G.-B.,Wuhan University | Liu L.,Wuhan University | Xie X.-F.,Wuhan University | Duan L.,Zhaojin Mining Industry Co.
Diqiu Kexue - Zhongguo Dizhi Daxue Xuebao/Earth Science - Journal of China University of Geosciences | Year: 2011

This paper summarizes in detail some advances in recent years about the ore-forming tectonic environment of VHMS type, SEDEX type and VSHMS type massive sulfide deposits, on which VHMS type deposit emphasizes three aspects as follows: the spatial and temporal distribution regularities of VHMS type ore deposits which occurred in intra-arc or backarc rift; metallogenic knowledge acquired from contrasting of ancient global VHMS type deposits; summary on the characteristics of lithological types and rock association, and general evolutionary processes of magma from modern seabed hydrothermal areas controlled under trench-island arc-backarc basin tectonic system. SEDEX type deposit emphasizes the metallogenic geodynamic environment from shale-hosted massive sulfide deposits of Proterozoic northeastern Australia. It is different from traditional understandings that these super-large size deposits do not occur in the intra-continental rift or aulocogen tectonic environments, whereas occurred in far-field backarc continental extension basin under plate convergent process, and it is especially pointed out that the paleaozoic typical SEDEX type deposit, such as Sullivan, Red dog, is also regarded as the same metallogenic geodynamic setting as their Proterozoic counterparts. Apart from this, these deposits under the tectonic environment related to convergent plate have more important ore-finding prospect. VSHMS type deposit was concerned much more in the latest ten years, although it has the similar ore ccurrence and metallogenic process as those deposits mentioned above, the different metallogenic tectonic environments, generally occurring in the transition tectonic setting between VHMS type and SEDEX type deposit, making it more important implication for tectonic setting. Accordingly, under convergent plate tectonic setting, from the plate boundary to far-field backarc intra-continental extension basin, a metallogenic sequence was established, i.e, VHMS→VSHMS→SEDEX.

Xu W.,China University of Mining and Technology | Song W.,University of Science and Technology Beijing | Cao S.,University of Science and Technology Beijing | Jiang G.,Zhaojin Mining Industry Co. | And 2 more authors.
Caikuang yu Anquan Gongcheng Xuebao/Journal of Mining and Safety Engineering | Year: 2015

To study the stability of stopes in an underground mine, an approach to analyze the stability of irregular ore pillar was established on the basis of Voronoi diagram. Taking Dayin'gezhuang Gold Mine as engineering background, the collapse modes of ore pillars and roofs were investigated and analyzed, and the main factors influencing pillar stability was put forward. In addition, orthogonal polar difference analysis was used to investigate the sensitivity of influencing factors, and the affecting sequence was listed from the most to minor. The stability status of ore pillars at-496m level were evaluated, and the results show that the safety coefficients of No.1-2, No.2-6, No.3-1, No.3-2 and No.4-2 ore pillars are all below 1.0. The stability of No.6203 Stope is the worst, and the pillars are extremely vulnerable to failure contiguously. Finally, support control measures were taken to ensure the stope stability. It is proved that the occurrence of roof caving and ore pillar fracturing is rapidly decreased, and the whole safety of mining stop is significantly improved. ©, YYYY, China University of Mining and Technology. All right reserved.

Chen G.,Kunming University | Chen J.,Kunming University | Zhang Z.Y.,Kunming University | Guo S.H.,Kunming University | And 6 more authors.
Metallurgist | Year: 2013

The present paper attempts to assess the effects of microwave irradiation on the leachability of refractory gold ores. Characteristics of the crystal structure and microstructure of the ores were determined by x-ray structural analysis (XRD) and scanning electron microscopy (SEM) before and after microwave irradiation. Compared to conventional processes, microwave leaching processes are highly energy-efficient, take less time, and do not harm the environment. The experimental results show that the amount of gold extracted increases with microwave leaching temperature. The results demonstrate that microwave irradiation techniques can be applied effectively and efficiently to the leaching of refractory gold ores. © 2013 Springer Science+Business Media New York.

Li Z.,University of Science and Technology Beijing | Chi W.,Zhaojin Mining Industry Co. | Liu J.,University of Science and Technology Beijing | Guo X.,University of Science and Technology Beijing | Li H.,University of Science and Technology Beijing
Advanced Materials Research | Year: 2013

The characteristics of process mineralogy of some pyrite cinders were studied with optics microscopes, scanning electron microscope, and x-ray diffraction. The chemical composition and the phase composition of the pyrite cinders were analyzed. The occurrence and chemical phase analysis of molybdenum of iron, copper, and gold were also studied. The behaviors of various minerals and mineralogical factors affecting the separation had been explained clearly. The investigation results were favorable to reasonable selection of technological process. © (2013) Trans Tech Publications, Switzerland.

Cao S.,University of Science and Technology Beijing | Du C.-F.,University of Science and Technology Beijing | Tang Z.-X.,Zhaojin Mining Industry Co. | Jiang G.-J.,Zhaojin Mining Industry Co. | Wu F.,Zhaojin Mining Industry Co.
Dongbei Daxue Xuebao/Journal of Northeastern University | Year: 2015

Based on the engineering background of Zhaoyuan Yingezhuang gold mine and by adopting the combination of theoretical calculation method and numerical simulation method, a research for the deep stope structure parameters optimization is carried out and the outcome has been applied to the in-situ mining. The research shows that the average maximum roof span is 8.3 m in theoretical calculation, and the pillar size is 6.1 m. The sensitivities of the factors that influence the stability of pillars are: pillar width>room width>mining depth>pillar height. It reveals the changing relationship between the pillar safety coefficient and the pillar width, room width, mining depth. Numerical simulation shows that a stope width of 8 m is reasonable. Through the application at the -616 m level, an ideal effect has been achieved, in return, it can provide solid basis for the stope structure optimization in deep mining. ©, 2015, Northeastern University. All right reserved.

Yu G.-M.,Qingdao Technological University | Song C.-W.,Qingdao Technological University | Zou J.-B.,Qingdao Technological University | Wu Y.-X.,Qingdao Technological University | And 5 more authors.
Transactions of Nonferrous Metals Society of China (English Edition) | Year: 2011

Considering its structural features, geometric shapes, service mode, environmental media, mechanical behavior, etc, the special nature and complexity of tailings dam were summarized. The technical approach to safety management for tailings dam was proposed, which is the on-line automated monitoring and early warning information. The results show that a strong theoretical basis can be provided for security monitoring and security management of tailings dam. Online automated monitoring system for tailings dam has full implementation of the information. It is applied widely in Lingnan gold mine, Xiadian gold mine and Hedong gold mine in Zhaoyuan, Shandong Province, and achieves good effect. © 2011 The Nonferrous Metals Society of China.

Song W.-D.,University of Science and Technology Beijing | Cao S.,University of Science and Technology Beijing | Fu J.-X.,University of Science and Technology Beijing | Jiang G.-J.,Zhaojin Mining Industry Co. | Wu F.,Zhaojin Mining Industry Co.
Yantu Lixue/Rock and Soil Mechanics | Year: 2014

To understand the sensitivity of factors influencing pillar stability, pillar arrangements in different sublevels are counted. Based on the local pillars in Dayingezhuang gold mine, pillar safety factor formulas of different forms were derived. Using six factors-five levels technology to design the experiment to analyze sensitivity of impact factors; at the same time this paper studies the relationships between pillar safety factor and pillar width, mining depth and room width. The study shows that the size of sensitivity of these factors affecting the stability of the pillar has been obtained via orthogonal experiment method and diminishes in turn: pillar width, mining depth, room width; in addition, the pillar safety factors follow the exponential function with the pillar width growth; follow power function with the mining depth decrease; and follow the exponential function with room width decrease. According to the pillar safety factor regression equation which is based on DPS and Matlab software, the minimum size of single-form pillar arrangement which satisfies both stability and security of the pillar has been reasonably obtained after analysis. Column width should be no less than 3.6 m; square column width should be 5.9 m or lager; and the room width should be no more than 8 m, which will certainly provide identifiable ground for the arrangements of pillar in deep middle section.

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