Structural and geochemical inter-relationships between gold and tungsten using arsenic as a proxy for gold
Year:
Project type:
Subject:
Advisers:
Abstract:
Studies of scheelite-sulphide rich ore from Macraes Mine, East Otago, New Zealand illustrate important relationships in terms of their spatial distribution and separation from each other. Understanding this relationship by observing the structural and geochemical inter-relationships between gold and tungsten, using arsenic as a proxy for gold has important economic implications in regards to wheather both gold and and scheelite (as a by-product) can be extracted together effectively. Past work has identified this as a possibility in a similar geological environment.
With the aid of UV-light, XRF, Microprobe and LA-ICP-MS techniques, results show a clear separation between arsenic (+ gold by association) and scheelite. Sulphides are distributed widely and occur at most concentrated levels within shears or micro-shears. They also appear on the edges, or even sometimes within the quartz-scheelite veins. This would suggest for at least one generation, mineralisation of sulphides and scheelite occurred together.
This study has identified that although in parts of the Macraes Deposit, there is a close relationship regarding the distribution of sulphides and scheelite, there is still the spatial separation as would be expected. Further work, ostensibly involving crushing size, will most likely be the important factor in terms of understanding the most effective way of beneficiating scheelite from the overall ore, followed by beneficiation of any remaining sulphides from within the scheelite itself.
With the aid of UV-light, XRF, Microprobe and LA-ICP-MS techniques, results show a clear separation between arsenic (+ gold by association) and scheelite. Sulphides are distributed widely and occur at most concentrated levels within shears or micro-shears. They also appear on the edges, or even sometimes within the quartz-scheelite veins. This would suggest for at least one generation, mineralisation of sulphides and scheelite occurred together.
This study has identified that although in parts of the Macraes Deposit, there is a close relationship regarding the distribution of sulphides and scheelite, there is still the spatial separation as would be expected. Further work, ostensibly involving crushing size, will most likely be the important factor in terms of understanding the most effective way of beneficiating scheelite from the overall ore, followed by beneficiation of any remaining sulphides from within the scheelite itself.
Thesis description:
72 leaves : ill. (some col.), maps ; 30 cm
Department:
OU geology Identifier:
2011Blackler
OURArchive handle:
OURArchive access level:
Collection
Citation
Blackler, Timothy Graeme, “Structural and geochemical inter-relationships between gold and tungsten using arsenic as a proxy for gold,” Otago Geology Theses, accessed February 8, 2025, https://theses.otagogeology.org.nz/items/show/532.