نتایج جستجو برای: sphalerite

تعداد نتایج: 465  

2005
K. D. KELLEY D. L. LEACH C. A. JOHNSON J. L. CLARK W. I. RIDLEY

The Red Dog Zn-Pb deposits are hosted in organic-rich mudstone and shale of the Mississippian Kuna Formation. A complex mineralization history is defined by four sphalerite types or stages: (1) early brown sphalerite, (2) yellow-brown sphalerite, (3) red-brown sphalerite, and (4) late tan sphalerite. Stages 2 and 3 constitute the main ore-forming event and are volumetrically the most important....

Journal: :Computers & Geosciences 2010
Deyi Xu Qiuming Cheng Zhijing Wang

Banding textures are commonly observed in mineral crystals for example in sphalerites in Mississippi Valley-type deposit. Cellular Nonlinear Network (CNN) has been developed in the literature for characterizing complexity especially for reaction-diffusion dynamic systems. These include models describing periodic precipitation incorporating nucleation and banding pattern formation in minerals. B...

2016
Thomas C. Robson

23 The biogeochemistry and bioavailability of cadmium, released during sphalerite 24 weathering in soils, were investigated under contrasting agricultural scenarios to assess 25 health risks associated with sphalerite dust transport to productive soils from mining. 26

2006
Raúl Hita

After the collapse on 25 Apr. 1998 of the Aznalcóllar mine tailings dike in southwestern Spain, 45 km of the Guadiamar valley were covered by a pyritic sludge containing up to 2% sphalerite (ZnS). Later, the sludge was mechanically removed and calcium carbonate was plowed into the soil to immobilize heavy metals. By June 2001 more than 60% of the sulfides in the residual sludge had oxidized and...

2012
Balasubramanian Vasanthakumar Honnavar Ravishankar Sankaran Subramanian

Environmental concerns regarding the use of certain chemicals in the froth flotation of minerals have led investigators to explore biological entities as potential substitutes for the reagents in vogue. Despite the fact that several microorganisms have been used for the separation of a variety of mineral systems, a detailed characterization of the biochemical molecules involved therein has not ...

2010
CHEN Jian-hua CHEN Ye LI Yu-qiong

The electronic properties of sphalerite (110) surface with Zn-vacancy and S-vacancy were calculated by using density-functional theory, and the effects of vacancy defect on the copper activation of sphalerite were investigated. The calculated results indicate that surface state occurs in the band gap of Zn-vacancy sphalerite, which is from the contribution of S 3p orbital at the first layer of ...

Journal: :Science 2000
M Labrenz G K Druschel T Thomsen-Ebert B Gilbert S A Welch K M Kemner G A Logan R E Summons G De Stasio P L Bond B Lai S D Kelly J F Banfield

Abundant, micrometer-scale, spherical aggregates of 2- to 5-nanometer-diameter sphalerite (ZnS) particles formed within natural biofilms dominated by relatively aerotolerant sulfate-reducing bacteria of the family Desulfobacteriaceae. The biofilm zinc concentration is about 10(6) times that of associated groundwater (0.09 to 1.1 parts per million zinc). Sphalerite also concentrates arsenic (0.0...

2017
Jianping Liu Raymond M. Coveney

Indium (In) is commonly hosted in Sn-rich deposits but rarely reported in Sn-poor deposits. However, an In-rich and Sn-poor skarn deposit, the Qibaoshan Cu-Zn-Pb deposit, has been identified in south China. Geochemical analyses were undertaken on 23 samples representing the following mineral assemblages: sphalerite-pyrite, pyrite-chalcopyrite, pyrite-sphalerite-galena-chalcopyrite, pyrite, magn...

Journal: :Colloids and surfaces. B, Biointerfaces 2011
C Y Jia D Z Wei P J Li X J Li P D Tai W Liu Z Q Gong

The adsorption of Mycobacterium Phlei cells on the surfaces of pyrite and sphalerite was studied as functions of time and pH. The results indicated that a higher amount of cells adsorbing onto pyrite compared with that onto sphalerite under neutral and alkaline conditions, and it was also observed from photographs of scanning electron micrograph. To gain a better insight into the mechanisms of ...

2014
Cui-hua ZHAO Jian-hua CHEN Bo-zeng WU Xian-hao LONG

Adsorption of water on sulfide surfaces and natural floatability of sulfide minerals were studied using density functional theory (DFT) method. All computational models were built in a vacuum environment to eliminate the effects of oxygen and other factors. H2O molecule prefers to stay with pyrite and sphalerite surfaces rather than water, whereas for galena, chalcocite, stibnite, and molybdeni...

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