A conceptual flowsheet for heap leaching of platinum group metals (PGMs) from a low-grade ore concentrate

This research proposes a new conceptual process to economically extract platinum group metals (PGMs), and as a secondary aim, base metals (BMs) from a low-grade concentrate originating from typical PGM concentrator plants. Slurry made from the concentrate was coated onto granite pebbles and packed i...

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Bibliographic Details
Main Authors: Mwase, J., Petersen, J., Eksteen, Jacques
Format: Journal Article
Published: Elsevier Science BV 2011
Subjects:
Online Access:http://hdl.handle.net/20.500.11937/47299
Description
Summary:This research proposes a new conceptual process to economically extract platinum group metals (PGMs), and as a secondary aim, base metals (BMs) from a low-grade concentrate originating from typical PGM concentrator plants. Slurry made from the concentrate was coated onto granite pebbles and packed into a column, in which it was bioleached with a mixed culture of thermophiles and mesophiles at 65 °C. After 30 days the extractions achieved were 52% copper, 95% nickel and 85% cobalt. The residual concentrate material was subsequently subjected to a cyanide leach also in a packed column operating at a room temperature of 23 °C. After 21 days 20.3% Pt, 87% Pd and 46% Rh were extracted. Using these results and projected extractions over longer operating times, a conceptual flowsheet was proposed for a possible process route to recover PGM values circumventing the problematic smelter route for this material.