China Nonferrous Metal Mining Group Co.

Changsha, China

China Nonferrous Metal Mining Group Co.

Changsha, China
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Yu Z.,University of Science and Technology Beijing | Jinfei C.,China Academy of Railway Sciences | Guang H.,University of Science and Technology Beijing | Guang H.,China Non ferrous Metal Mining Group Co.
Engineering Review | Year: 2017

Taking the Muliashi north open-pit mine in Zambia as a case study, the failure mechanism of rock slope with intermittent bedding joints was investigated from a meso mechanical viewpoint using particle flow theory and PFC2D software. In the rock slope model, the rock block and joint were represented by bonded-particle model and smooth-joint model, respectively. The main research results are as follows: (1) Due to orientation and discontinuities of joint, the sliding shape at the bottom of the sliding mass is relatively straight, while the tailing edge shape of sliding mass is flexural and is presenting step-path failure. (2) The fragmented particle assemblies of sliding mass are primarily generated in the middle and bottom part of slope. And they are subsequently generated in the top part of slope. The bulk of fragmented particle assemblies in the middle and bottom part are relatively larger than those in the top part. (3) At the end of sliding process, the contact force of particle is relatively larger along with the direction of rock bridge, and the effect of stress arch is generated around the primary joints. (4) During the sliding process of rock slope, the relationship between the magnitude and count of microseismic events obeys the normal distribution function approximately.

Li J.,CAS Institute of Tibetan Plateau Research | Qin K.,CAS Institute of Geology and Geophysics | Li G.,CAS Institute of Geology and Geophysics | Cao M.,CAS Institute of Geology and Geophysics | And 8 more authors.
Mineralogy and Petrology | Year: 2012

The Yulong porphyry copper deposit (6.5 Mt at 0.46 % Cu) in eastern Tibet was formed in a post-collisional setting. New zircon U-Pb and U-Th/He ages, apatite U-Th/He ages and in-situ zircon Hf isotopic and trace element data for the Yulong ore-bearing adakitic porphyries elucidate the thermal history and petrogenesis of the deposit. Zircon U-Pb ages range from from 41.2 Ma to 40.7 Ma, indicating an Eocene formation age. Combined with the zircon U-Th/He age of 37.5 ± 1.2 Ma, results suggest that magmatic-hydrothermal evolution lasted up to 5 m. y. The apatite U-Th/He age of 33.4 ± 0.9 Ma reflects Yulong deposit exhumation during the ~33-30 Ma Tibetan uplift. Moreover, the high εHf(t)-values (7.1 ~ 12.2) zircon yield the highest ΣREE content, higher Y/Hf, lower Ce/Ce* and higher Th/U ratios compared to inherited zircon or magmatic zircon suggesting that the high εHf(t) zircon crystallized from another magma, and that magma mixing probably contributed to the adakitic porphyries at Yulong. In addition, inherited and magmatic zircon with the lowest εHf(t) values (-20.6 ~ -4.4) suggest crustal contamination. The positive zircon εHf(t) values indicate a source in the juvenile arc lower crust. Significantly, the juvenile arc lower crust inherited arc magma characteristics (abundant F, Cl, Cu and high oxidation state), which are now found in the porphyry Cu-Mo deposits. © 2012 Springer-Verlag.

Li J.-X.,CAS Institute of Tibetan Plateau Research | Li J.-X.,Chinese Academy of Sciences | Qin K.-Z.,CAS Institute of Geology and Geophysics | Li G.-M.,CAS Institute of Geology and Geophysics | And 5 more authors.
Geological Journal | Year: 2016

The Duolong porphyry Cu-Au deposit (5.4Mt at 0.72% Cu, 41t at 0.23g/t Au) was recently discovered in the southern Qiangtang terrane, central Tibet. Here, new whole-rock elemental and Sr-Nd-Pb isotope and zircon Hf isotopic data of syn- and post-ore volcanic rocks and barren and ore-bearing granodiorite porphyries are presented for a reconstruction of magmas associated with Cu-Au mineralization. LA-ICP-MS zircon U-Pb dating yields mean ages of 117.0±2.0 and 120.9±1.7Ma for ore-bearing granodiorite porphyry and 105.2±1.3Ma for post-ore basaltic andesite. All the samples show high-K calc-alkaline compositions, with enrichment of light rare earth elements (LREE) and large ion lithophile elements (LILE: Cs and Rb) and depletion of high field strength elements (HFSE: Nb and Ti), consistent with the geochemical characteristics of arc-type magmas. Syn- and post-ore volcanic rocks show initial Sr ratios of 0.7045-0.7055, εNd(t) values of -0.8 to 3.6, (206Pb/204Pb)t ratios of 18.408-18.642, (207Pb/204Pb)t of 15.584-15.672 and positive zircon εHf(t) values of 1.3-10.5, likely suggesting they dominantly were derived from metasomatized mantle wedge and contaminated by southern Qiangtang crust. Compared to mafic volcanic rocks, barren and ore-bearing granodiorite porphyries have relatively high initial Sr isotopic ratios (0.7054-0.7072), low εNd(t) values (-1.7 to -4.0), similar Pb and enriched zircon Hf isotopic compositions [εHf(t) of 1.5-9.7], possibly suggesting more contribution from southern Qiangtang crust. Duolong volcanic rocks and granodiorite porphyries likely formed in a continental arc setting during northward subduction of the Bangong-Nujiang ocean and evolved at the base of the lower crust by MASH (melting, assimilation, storage and homogenization) processes. © 2016 John Wiley & Sons, Ltd.

Li J.-X.,CAS Institute of Tibetan Plateau Research | Qin K.-Z.,CAS Institute of Geology and Geophysics | Li G.-M.,CAS Institute of Geology and Geophysics | Xiao B.,CAS Institute of Geology and Geophysics | And 4 more authors.
Lithos | Year: 2013

The Duolong porphyry Cu-Au deposit (5.4Mt at 0.72% Cu, 41t at 0.23g/t Au), which is related to the granodiorite porphyry and the quartz-diorite porphyry from the Bangongco copper belt in central Tibet, formed in a continental arc setting. Here, we present the zircon U-Pb ages, geochemical whole-rock, Sr-Nd whole-rock and zircon in-situ Hf-O isotopic data for the Duolong porphyries. Secondary ion mass spectrometry (SIMS) zircon U-Pb analyses for six samples yielded consistent ages of ~118Ma, indicating a Cretaceous formation age. The Duolong porphyries (SiO2 of 58.81-68.81wt.%, K2O of 2.90-5.17wt.%) belong to the high-K calc-alkaline series. They show light rare earth element (LREE)-enriched distribution patterns with (La/Yb)N=6.1-11.7, enrichment in large ion lithophile elements (e.g., Cs, Rb, and Ba) and depletion of high field strength elements (e.g., Nb), with negative Ti anomalies. All zircons from the Duolong porphyries share relatively similar Hf-O isotopic compositions (δ18O=5.88-7.27-; εHf(t)=3.6-7.3), indicating that they crystallized from a series of cogenetic melts with various degrees of fractional crystallization. This, along with the general absence of older inherited zircons, rules out significant crustal contamination during zircon growth. The zircons are mostly enriched in δ18O relative to mantle values, indicating the involvement of an 18O-enriched crustal source in the generation of the Duolong porphyries. Together with the presence of syn-mineralization basaltic andesite, the mixing between silicic melts derived from the lower crust and evolved H2O-rich mafic melts derived from the metasomatized mantle wedge, followed by subsequent fractional crystallization (FC) and minor crustal contamination in the shallow crust, could well explain the petrogenesis of the Duolong porphyries. Significantly, the hybrid melts possibly inherited the arc magma characteristics of abundant F, Cl, Cu, and Au elements and high oxidation state, which contributed to the formation of the Duolong porphyry Cu-Au deposit. © 2013 Elsevier B.V..

Zheng G.-L.,Central South University | Zhu D.-Q.,Central South University | Pan J.,Central South University | Li Q.-H.,Central South University | And 3 more authors.
Journal of Central South University | Year: 2014

The enrichment of Ni from a low-grade saprolitic laterite ore, which has been pre-treated by high pressure grinding roller(HPGR) to be 74% passing 0.074 mm and contains 0.92% Ni, 18.47% Fe, 10.61% MgO and 42.27% SiO2, was conducted by using pelletizing, rotary kiln reduction and magnetic separation process on a semi industrial scale, and the effects of reduction duration, mass ratio of coal to pellets(C/P), the types of magnetic separator, the sections of grinding-separation and the grinding fineness on the recovery of Ni and Fe were examined. It is shown that nickel concentrate containing 3.13 % Ni and 59.20 % Fe was achieved at recoveries of 84.36 % and 71.51 % for Ni and Fe, respectively under the following conditions: reducing at (1120±40) °C for 120 min, C/P being 1.0, wet grinding of reduced pellets up to 70%-87% passing 0.074 mm and a magnetic field intensity of 238.8 kA/m during the first section of grinding-magnetic separation, and a grinding fineness of 84%-91% passing 0.045 mm and a magnetic intensity of 39.8 kA/m during the second section of grinding-magnetic separation. The enriched Ni containing concentrate has a low content of S and P, and can be used for further processing to produce high-grade ferronickel alloy. © 2014 Central South University Press and Springer-Verlag Berlin Heidelberg.

Wang Y.M.,University of Science and Technology Beijing | Huang M.Q.,University of Science and Technology Beijing | Wu A.X.,University of Science and Technology Beijing | Yao G.H.,China Nonferrous Metal Mining Group Co. | Hu K.J.,University of Science and Technology Beijing
Applied Mechanics and Materials | Year: 2013

Goafs formed in mine-out areas threat the underground mines owing to possibilities of rock burst and surface subsidence. This paper aims to discuss the feasibility, design and construction of waste rock backfill in abandoned stopes. Based on goafs distribution and stabilities in the White Bull Mine, rock backfill system with a total volume of 362,000 m3 in 8 gobs was designed and carried out. The system included technologically and economically feasible stopes, conveying equipments of tramcars, rock transfer by electric rakes, haulage network and mining workings. Field effects showed that rock backfill was applicable to control potential hazards. With rock filling, goaf utilization rates ranged from 60% to 70%, which helped to control adjacent rock movement, eliminate rock burst and surface subsidence. Additionally, backfill construction reduced the lift and transportation costs of rocks by about 50%, which further lowered the land usage of surface dumping. © (2013) Trans Tech Publications, Switzerland.

Jiang S.-H.,Chinese Academy of Geological Sciences | Bagas L.,Chinese Academy of Geological Sciences | Bagas L.,University of Western Australia | Hu P.,China Nonferrous Metal Mining Group Company | And 4 more authors.
Lithos | Year: 2016

The Shamai tungsten deposit is located in the eastern part of the Central Asian Orogenic Belt (CAOB). Tungsten mineralization is closely related to the emplacement of fine- to medium-grained biotite monzogranite (G1) and porphyritic biotite monzogranite (G2) in the Shamai Granite. NW-trending joints and faults host orebodies in the Shamai Granite and Devonian hornfels. The mineralization is characterized by a basal veinlet zone progressing upwards to a thick vein zone followed by a mixed zone, a veinlet zone, and a thread vein zone at the top. The ore-related alteration typically consists of muscovite, greisen, and hornfels.In order to constrain the timing of the Shamai mineralization and discuss the ore genesis, muscovite Ar-Ar, molybdenite Re-Os, and zircon U-Pb geochronological, geochemical, and Sr-Nd-Hf isotopic studies were completed on the deposit. The U-Pb zircon dating yielded weighted mean ages of 153. ±. 1. Ma for G1 and 146. ±. 1. Ma for G2. Muscovite from a wolframite-bearing quartz vein yielded an Ar-Ar plateau age of 140. ±. 1. Ma, whereas two molybdenite samples yielded identical Re-Os model ages of 137. ±. 2. Ma. These two ages are younger than the two monzogranites, suggesting a prolonged magmatic-hydrothermal interaction during tungsten mineralization.Major and trace element geochemistry shows that both G1 and G2 are characterized by high SiO2 and K2O contents, high A/CNK values (1.08-1.40), a spectacular tetrad effect in their REE distribution patterns, and non-CHARAC (charge-and-radius-controlled) trace element behavior. This suggests that both G1 and G2 are highly differentiated peraluminous rocks with strong hydrothermal interaction. The Nd-Hf isotope data for the Shamai Granite (εNd(t) between -1.9 and +7.4, e(open)Hf(t) from 5.2 to 12.8) are largely compatible with the general scenario for much of the Phanerozoic granite emplaced in the CAOB. It is here suggested that the Shamai Granite originated from partial melting of a juvenile lower crust with minor input of upper crustal material caused by the underplating of mafic magma in an extensional setting. It can also be concluded that the prolonged fractional crystallization and magmatic-hydrothermal interactions have contributed to the formation of the Shamai tungsten deposit. © 2015 Elsevier B.V.

Han G.,University of Science and Technology Beijing | Han G.,China Non ferrous Metal Mining Group Co. | Zhou Y.,University of Science and Technology Beijing | Hu N.-L.,University of Science and Technology Beijing | Gan Y.-X.,University of Science and Technology Beijing
Dongbei Daxue Xuebao/Journal of Northeastern University | Year: 2015

The equivalent crystal model of granite reflecting the meso structure features of mineral grain was constructed with bonded particle model and smooth joint model. Afterwards it was loaded by uniaxial compression, and the fracture mechanism and energy evolution law of granite were deeply revealed from mesoscopic viewpoint. Research shows that: during loading process, normal fracture and shear fracture generate successively on the boundary of the crystalline body; close to the peak compressive strength, normal fracture breaking grain generates in the crystalline body. The penetrating flaws generated by cracks lead to macro splitting failure of specimen. Strain and bond energy increase gradually before specimen failure, while after that, strain and bond energy reduce sharply with strain increase. Kinetic energy is almost zero and frictional energy increases slowly before peak strength, while after that, kinetic energy changes violently, and frictional energy begins to play a dominant role. ©, 2015, Northeastern University. All right reserved.

Guang H.,University of Science and Technology Beijing | Guang H.,China Non ferrous Metal Mining Group Co. | Bing L.,University of Science and Technology Beijing | Zhou Y.,University of Science and Technology Beijing
Electronic Journal of Geotechnical Engineering | Year: 2016

Production blasting in open-pit mine has a significant impact on the stability of the slope. The slope of Zambia Muliashi open-pit copper mine was selected as the engineering background. In order to analyze the vibration mechanics response of slope under blasting, dynamical response time-dependent analysis method and ANSYS program were used. The study indicated that the differences of the horizontal displacement-time curves of the particles at the edge of the slope were big whilethat of vertical ones were smaller. When the particles were high and the distance of them to the edge was small, displacement amplification effect was significant. Elevation amplification effect of horizontal displacement was relatively obvious before attenuation of the acceleration of blasting. With the increase of time, the higher the slope was, the larger the amplitude of horizontal displacement was. © 2016 ejge.

Zhu D.,Central South University | Zheng G.,Central South University | Pan J.,Central South University | Li Q.,Central South University | And 2 more authors.
TMS Annual Meeting | Year: 2014

Low-grade laterite ore has not been well utilized to produce ferronickel directly due to intensive energy consumption. The mineralogy of a low-grade saprolitic nickel laterite ore was studied and the effect of sodium carbonate and calcium carbonate on the enrichment of nickel and iron as concentrate from this ore was investigated by using coal-based reduction followed by magnetic separation on bench scale. Optical microscope, X-ray diffraction and scanning electron microscope(SEM) were used to characterize the laterite ore and the reduced briquettes. It is shown that sodium carbonate reacted with quartz and forsterite to form sodium-magnesium silicate, enhancing the reduction of nickel, while the formation of calcium-magnesium silicate by adding calcium carbonate facilitated the reduction of iron and the growth of Fe-Ni grains. In the presence of additives, concentrate with 4.28 % nickel and 62.77 % iron was obtained at recoveries of 84.40 %, 78.44 % for nickel and iron, respectively. Copyright © 2014 by The Minerals, Metals & Materials Society.

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