Controls on the Formation of Komatiite-Associated Nickel-Copper Sulfide Deposits

1986 ◽  
pp. 43-62 ◽  
Author(s):  
C. M. Lesher ◽  
D. I. Groves
Keyword(s):  
Copper Sulfide ◽  
Sulfide Deposits ◽  
Nickel Copper

Significance of compositional zoning in cumulate chromites of the Kabanga chonoliths, Tanzania

2018 ◽  
Vol 82 (3) ◽  
pp. 675-696 ◽  
Author(s):  
David M. Evans
Keyword(s):  
Divalent Cations ◽  
Chrome Spinel ◽  
Compositional Zoning ◽  
Sulfide Deposits ◽  
Nickel Copper ◽  
History Of ◽  
Trivalent Cations ◽  
Indicator Mineral ◽  
Normal Zoning ◽  
North Western

ABSTRACTCompositional zoning is observed rarely in chrome-spinel grains from slowly-cooled layered intrusions because diffusion of cations continues within the spinel to low temperatures. However, in certain circumstances, such gradational zoning of both divalent and trivalent cations is observed and may be useful in deciphering the thermal history of the host intrusions. The accessory chrome-spinels of the Kabanga mafic-ultramafic chonolith intrusions of the Kibaran igneous event in north western Tanzania are notable because they have preserved gradational compositional zoning. This zoning is demonstrated to predate and be independent of later hydrous alteration of the silicate assemblage. At Kabanga, most chrome-spinel grains within olivine-rich cumulate rocks are gradationally and cryptically zoned from Fe2+-Cr3+ rich cores to more Mg2+-Al3+ rich rims (normal zoning). A few grains are zoned from Mg2+-Al3+ rich cores to more Fe2+-Cr3+ rich rims (reverse zoned). The zoning of divalent cations is proportional to that of trivalent cations with Mg2+ following Al3+ and Fe2+ following Cr3+ from core to rim. The zoning of trivalent and tetravalent cations is interpreted to be caused by either new growth from an evolving melt or peritectic reactions between evolved or contaminated melt and adjacent Al-Cr-bearing ferromagnesian minerals, which is preserved by relatively rapid initial cooling in the small chonolith intrusions. Divalent cation zoning is controlled by sub-solidus exchange of Fe2+ and Mg with adjacent ferromagnesian minerals and continues to lower temperatures, indicated to be 580 to 630°C by the spinel-olivine geothermometer. Preservation of such zoning is more likely in the smaller chonolith intrusions that typically host magmatic nickel-copper sulfide deposits and can be used as an exploration indicator when interpreting chromite compositions in regional heavy indicator mineral surveys.

Preparation of nanoporous nickel copper sulfide on carbon cloth for high-performance hybrid supercapacitors

2018 ◽  
Vol 273 ◽  
pp. 170-180 ◽  
Author(s):  
Dongwei Du ◽  
Rong Lan ◽  
John Humphreys ◽  
Houari Amari ◽  
Shanwen Tao
Keyword(s):  
Copper Sulfide ◽  
High Performance ◽  
Carbon Cloth ◽  
Hybrid Supercapacitors ◽  
Nickel Copper

Partition coefficients for Ni, Cu, Pd, Pt, Rh, and Ir between monosulfide solid solution and sulfide liquid and the formation of compositionally zoned Ni – Cu sulfide bodies by fractional crystallization of sulfide liquid

1997 ◽  
Vol 34 (4) ◽  
pp. 366-374 ◽  
Author(s):  
Sarah-Jane Barnes ◽  
E. Makovicky ◽  
M. Makovicky ◽  
J. Rose-Hansen ◽  
S. Karup-Moller
Keyword(s):  
Solid Solution ◽  
Sulfur Content ◽  
Fractional Crystallization ◽  
Copper Sulfide ◽  
Partition Coefficients ◽  
Crystal Fractionation ◽  
Sulfide Liquid ◽  
Monosulfide Solid Solution ◽  
Experimental Systems ◽  
Nickel Copper

Many nickel–copper sulfide orebodies contain Cu- and Fe-rich portions. The Fe-rich ore is generally richer in Os, Ir, Ru, and Rh and poorer in Pt, Pd, and Au than the Cu-rich ore. In komatiite-hosted ores Ni tends to be concentrated in the Cu-rich ore, whereas in tholeiitic ores it tends to be concentrated in the Fe-rich ore. The origin of this zonation could be due to crystal fractionation of Fe-rich monosulfide solid solution from a sulfide liquid. The crystal fractionation would produce an Fe-rich cumulate enriched in Os, Ir, Ru, and Rh and a fractionated liquid enriched in Cu, Pt, Pd, and Au. This model can be tested for zoned orebodies by applying experimentally determined partition coefficients for the metals into monosulfide solid solution. We have compared our experimental results with those of other workers to show that the partition coefficients are strongly influenced by the sulfur content of the system. There is a positive correlation between the partition coefficients and sulfur content of the monosulfide solid solution and between the partition coefficients and the sulfur content of the liquid. In sulfur-saturated and sulfur-over-saturated experimental systems, the metals behave in a manner consistent with the model, that is, Os, Ir, Ru, and Rh are compatible with monosulfide solid solution, Cu, Pd, and Pt are incompatible, and Ni has a partition coefficient close to 1. The use of the experimental partition coefficients is demonstrated in the numerical modelling of a zoned komatiite-related ore (Alexo, Abitibi Greenstone Belt) and a zoned tholeiite-related ore (Oktyabr'sky, Noril'sk region, Siberia). In both cases, the experimental partition coefficients numerically model the composition zones of the actual ores. This supports the model of fractional crystallization of a monosulfide solid solution from a sulfide liquid to form zoned orebodies. Furthermore, it indicates that the experimentally determined partition coefficients are geologically reasonable.

The effect of a new polysaccharide on the depression of talc and the flotation of a nickel–copper sulfide ore

2015 ◽  
Vol 77 ◽  
pp. 99-106 ◽  
Author(s):  
Kaile Zhao ◽  
Guohua Gu ◽  
Changliang Wang ◽  
Xiying Rao ◽  
Xiaohui Wang ◽  
...  
Keyword(s):  
Copper Sulfide ◽  
Nickel Copper ◽  
Sulfide Ore ◽  
Copper Sulfide Ore
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