Prof. Reid Keys Honours Projects
Geochemistry and recovery of Scandium from laterite deposits
Lateritization of the ultramafic rocks of the Owendale Complex has produced significant Sc, Pt , Ni and Co mineralization. Using a Sc cut off grade of 300 ppm Sc, Platina Resources has announced a mineral resource at Owendale of 33.7 million tonnes @ 395 ppm Sc, 0.28 g/t Pt, 0.11% Ni and 0.06% Co (http://www.platinaresources.com.au/wp-content/uploads/2017/08/2017.08.09-ASX-August-2017-resource-update.pdf). Although a considerable amount is known about the geochemical processes that produce economic Ni laterite deposits, much less is known about the geochemical processes that generate significant Sc laterite deposits. Although about a half of the world’s Ni production comes from laterites, no Sc is currently being recovered from laterites. The aims of the project are 1) to provide insights into the geochemical processes that produce Sc enrichment in laterites and 2) develop techniques to recover Sc from laterites. Aim (1) will be achieved by using Platina’s assay data to document the vertical variations in geochemistry and by carrying out XRD analyses of strategic samples from the laterite profile. Aim (2) will address by carrying out heating and leaching experiments to determine if it is possible to establish a more efficient and economic method of Sc recovery from laterites than the High Pressure Acid Leach (HPAL) methods used to recover Ni from some Ni laterite deposits.
Wall rock alteration associated with Sn-Cu mineralization in the Cleveland Sn-Cu deposit, Tasmania
Supervisors: Reid Keays and Peter Jackson
Field of Study: Economic Geology/ Geochemistry
Support offered: All analytical & thesis-preparation costs
Preferred program: Honours
The Cleveland Sn-Cu deposit in Tasmania was the second largest Sn producer in Australia when it closed in 1986. The mineralization is localized around a quartz porphyry dyke which is associated with the Meredith Granite and which intruded greywackes and shales. A very large alteration halo surrounds the quartz porphyry dyke; the alteration halo is associated with a minimum of 13 vein systems with very well developed alteration envelops around them. Vein filling can be divided into four sequential stages based on mineral assemblages, viz: Stage 1 (Siliceous Stage) – dominantly quartz; Stage 2 (Greisen 1 Stage) – quartz + muscovite + wolframite + molybdenite; Stage 3 (Greisen 2 Stage) – topaz and fluorite rich veins with increasing sulphide and cassiterite content towards end of stage; and Stage 4 (Carbonate Stage) – carbonate and fluorite veins The aim of the project is to compare and contrast the hydrothermal alteration associated with the different types of vein assemblages and to use isocon diagrams to establish which elements were depleted and which enhanced during alteration. This aim would be accomplished by petrographic studies of existing thin sections and utilizing a large geochemical data base of the altered rocks. Variations in the composition of biotite and chlorite with alteration style would be determined using the Electron Microprobe. A useful reference is: Jackson, P., Changkakoti, A., Krouse, H.R. and Gray, J. (2000). The origin of greisen fluids of the Foley’s Zone, Cleveland Tin Deposit, Tasmania, Australia. Econ. Geol. V. 95: 227-236.
For further information contact Reid Keays