Platinum-Group Element Distribution in Some Ore Deposits: Results of EPMA and Micro-PIXE Analyses

2004 ◽  
Vol 147 (3) ◽  
Author(s):  
Fernando Gervilla ◽  
Louis J. Cabri ◽  
Kari Kojonen ◽  
Thomas Oberth�r ◽  
Thorolf W. Weiser ◽  
...  
Keyword(s):  
Platinum Group Element ◽  
Element Distribution ◽  
Ore Deposits ◽  
Group Element ◽  
Platinum Group

Review of platinum-group element distribution and mineralogy in chromitite ores from southern Iran

2012 ◽  
Vol 48 ◽  
pp. 278-305 ◽  
Author(s):  
Mohammad Reza Jannessary ◽  
Frank Melcher ◽  
Jerzy Lodziak ◽  
Thomas C. Meisel
Keyword(s):  
Platinum Group Element ◽  
Element Distribution ◽  
Group Element ◽  
Southern Iran ◽  
Platinum Group

Magnetic signature of magnetite‐enriched rocks hosting platinum‐group element mineralization within the Archean Boston Creek Flow, Ontario

Geophysics ◽  
1998 ◽  
Vol 63 (2) ◽  
pp. 440-445 ◽  
Author(s):  
Michelle S. Larson ◽  
William E. Stone ◽  
William A. Morris ◽  
James H. Crocket
Keyword(s):  
Platinum Group Element ◽  
Magnetic Anomalies ◽  
Ore Deposits ◽  
Group Element ◽  
Rock Types ◽  
Platinum Group Minerals ◽  
Pge Mineralization ◽  
Geophysical Surveys ◽  
Close Proximity ◽  
Platinum Group

Ground‐based magnetometer surveys detect high‐positive magnetic anomalies (up to 72 000 nT) which coincide with the location of subeconomic, magnetite‐associated platinum‐group element (PGE) mineralization within the Boston Creek Flow iron‐rich basalt, Archean Abitibi Greenstone Belt, Ontario. The magnetic anomalies confirm the presence of magnetite‐enriched zones (up to 20 modal%), and reveal that they are ovoid in shape, up to 10 m in size, and along strike from each other in the central gabbro‐diorite layer. Geological and geochemical surveys and mineralogical studies indicate that these zones host smaller zones of disseminated chalcopyrite + pyrite, some of which, in turn, host platinum‐group minerals (PGM) and are enriched in PGE and related metals (whole‐rock [Formula: see text], Ag = 1300 ppb, Cu = 0.3%, V = 0.1%, Ni = 0.05%, Ti = 2.5%, and Fe = 25%). The coincidence of the high‐positive magnetic anomalies with the location of PGE mineralization, points to ground‐based magnetometer surveys as a valuable exploration tool for magnetite‐associated PGE ore deposits. The distribution of the residual magnetic field anomalies indicate that such surveys are especially useful in: (1) identifying rock types and mapping their distribution in areas of limited outcrop exposure; (2) locating magnetite‐enriched gabbroic rock bodies, even in close proximity to serpentinized olivine cumulate rocks; and (3) delineating the detailed geometry of magnetite‐enriched rocks that may carry significant amounts of PGE and PGMs. Exploration strategies should be designed to use ground‐based geophysical surveys, in conjunction with geological and geochemical surveys, to locate and delineate the geometry of magnetite‐enriched zones within thick, differentiated mafic‐ultramafic volcanic flows and plutonic bodies.

Supergene mobilization and redistribution of platinum-group elements in the Merensky Reef, eastern Bushveld Complex, South Africa

2021 ◽  
Vol 59 (6) ◽  
pp. 1381-1396
Author(s):  
Maximilian Korges ◽  
Malte Junge ◽  
Gregor Borg ◽  
Thomas Oberthür
Keyword(s):  
South Africa ◽  
Platinum Group Element ◽  
Bushveld Complex ◽  
Platinum Group Elements ◽  
Element Distribution ◽  
Group Element ◽  
Recovery Rates ◽  
Merensky Reef ◽  
Platinum Group Minerals ◽  
Platinum Group

ABSTRACT Near-surface supergene ores of the Merensky Reef in the Bushveld Complex, South Africa, contain economic grades of platinum-group elements, however, these are currently uneconomic due to low recovery rates. This is the first study that investigates the variation in platinum-group elements in pristine and supergene samples of the Merensky Reef from five drill cores from the eastern Bushveld. The samples from the Richmond and Twickenham farms show different degrees of weathering. The whole-rock platinum-group element distribution was studied by inductively coupled plasma-mass spectrometry and the platinum-group minerals were investigated by reflected-light microscopy, scanning electron microscopy, and electron microprobe analysis. In pristine (“fresh”) Merensky Reef samples, platinum-group elements occur mainly as discrete platinum-group minerals, such as platinum-group element-sulfides (cooperite–braggite) and laurite as well as subordinate platinum-group element-bismuthotellurides and platinum-group element-arsenides, and also in solid solution in sulfides (especially Pd in pentlandite). During weathering, Pd and S were removed, resulting in a platinum-group mineral mineralogy in the supergene Merensky Reef that mainly consists of relict platinum-group minerals, Pt-Fe alloys, and Pt-oxides/hydroxides. Additional proportions of platinum-group elements are hosted by Fe-hydroxides and secondary hydrosilicates (e.g., serpentine group minerals and chlorite). In supergene ores, only low recovery rates (ca. 40%) are achieved due to the polymodal and complex platinum-group element distribution. To achieve higher recovery rates for the platinum-group elements, hydrometallurgical or pyrometallurgical processing of the bulk ore would be required, which is not economically viable with existing technology.

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