Recent research on black shale hosted base-metal deposit of the Mount Isa region, northern Australia
- Authors: Andy, Wilde , McKnight, Stafford
- Date: 2007
- Type: Text , Conference paper
- Relation: Ninth Biennial SGA Meeting, Dublin 2007, Dublin: Ireland p. 307-309
- Full Text: false
- Reviewed:
- Description: Recent research as part of the Co-operative Research Centre in Predictive Mineral Discovery has addressed a number of issues pertaining to the giant base-metal deposits of the Mount Isa Region of northern Australia.
- Description: E1
- Description: 2003005459
The Fosterville (central Victoria, Australia) and globe-progress (Reefton, South Island, New Zealand) deposits : Examples of shear zone-related disseminated-style systems in low-grade metamorphic terrains
- Authors: Bierlein, Frank , Christie, Anthony B , McKnight, Stafford
- Date: 2002
- Type: Text , Conference paper
- Relation: 114th Annual Meeting of the Geological Society of America , Colorado
- Full Text: false
- Description: Orogenic gold deposits in central Victoria and Reefton formed during the evolution of a Paleozoic accretionary system along the Pacific margin of Gondwana. The majority of deposits in both camps are characterised by coarse-grained gold that is hosted in laminated to massive quartz veins. These ‘lode’ structures are developed in isoclinally folded turbidites that have been metamorphosed to lower greenschist facies. At Fosterville, diffuse zones of mineralization occur along a high-angle reverse fault zone consisting of en-échelon, strike-parallel segments with oblique slip and strike slip movement. The Globe-Progress deposit is associated with an arcuate shear that flattens with depth forming a listric ramp flat. In contrast to ‘classic’ lode-style deposits, mineralization at Fosterville and Globe-Progress is predominantly hosted by massive sandstone beds, in quartz/carbonate vein stockworks, and in clay-rich fault breccias of quartz vein and sulfidic wall rock fragments. The porous sandstones, which are intercalated with carbonaceous slates, have a bleached appearance, are invariably sericitized and carbonatized, and are 'impregnated' with a disseminated arsenopyrite-pyrite(±stibnite) assemblage. Gold occurs as sub-micron inclusions within the sulfides and rarely as free grains with a diameter of 1-10 microns. Highest-grade disseminated mineralization occurs within acicular arsenopyrite crystals. Fluid inclusions from Fosterville range in composition from high salinity and relatively high CO2, to low salinity and H2O-predominance, suggesting precipitation of at least a portion of the veins under epizonal conditions.....
- Description: 2003004220
High grade Au-Sb vein-type mineralisation at Fosterville
- Authors: Dowling, Kim , McKnight, Stafford , Kotsonis, Andrew
- Date: 2001
- Type: Text , Conference paper
- Relation: Paper presented at 3rd Conference on Developments in Victorian Geology and Mineralisation, Ballarat : 26th-27th April 2001
- Full Text: false
The development of heavy suspension techniques for high density sink-float separations (replacement of Clerici's solution)
- Authors: Klutke, Cameron , Koroznikova, Larissa , McKnight, Stafford , Hall, Stephen
- Date: 2006
- Type: Text , Conference paper
- Relation: Paper presented at The AusIMM new Leaders Conference 2006, Kalgoorlie : 11th April, 2006
- Full Text: false
- Reviewed:
- Description: Mineral sands represent an important new resource being developed in the Murray Basin, including parts of western Victoria. This paper will outline a simple methodology for mineral sands characterisation, developed as part of the AMIRA-managed project P777 ‘The Development of Heavy Suspension Techniques for High Density Separations (Replacement of Clerici’s Solution)’. This project is currently sponsored by three multinational mining companies (De Beers Consolidated Mines, Iluka Resources Limited and Rio Tinto Limited) and is developing an innovative laboratory mineral characterisation procedure that will allow the replacement of the currently employed highly-toxic chemicals. Mineral sand resources almost always contain more than one valuable (and relatively heavy) mineral. Titanium minerals are found with a large range of titanium contents, giving rise to density variation and often subjective mineralogical descriptions. Companies tend to rely on laboratory heavy liquid separation in the evaluation of samples arising from exploration, mining or metallurgical processes. Unfortunately, there are only a limited number of high density (‘heavy’) liquids and these tend to be more toxic as their density increases. Low-toxicity inorganic solutions, based on tungsten compounds, have been developed that can be utilised at relative densities (RD) up to 3.0. However, beyond this value currently only organic liquids can be used. Diiodomethane (methylene iodide) having a relative density of 3.31 is commonly used; however, this presents significant health and safety hazards. Mixtures of thallium formate and thallium malonate were found in the early 1900s by Clerici to provide liquids having specific gravities between 4.0 and 5.0, hence ‘Clerici’s solution’. For the characterisation of the heavy components of mineral sand deposits (eg anatase sg 3.9, rutile sg 4.2, ilmenite sg 4.4 – 4.7 and zircon sg 4.6 – 4.8) there is currently no heavy liquid alternative to Clerici’s solution. Clerici’s solution is highly toxic and testing is now conducted by very few laboratories worldwide with costs reflecting the chemical costs (though extensive efforts are made to recover and reuse the liquid, plus the requirement of its removal from the mineral samples), the infrastructure costs and health and safety regimes (eg blood testing of exposed staff, inventory management). A simple laboratory technique of density fractionation is being developed, employing suspensions of fine tungsten carbide particles in lithium heteropolytungstate (LST) solutions, that can replace Clerici’s solution in the evaluation of fine mineral sands samples (eg -250+150 microns). The developing methodology that can achieve low-cost, low-toxic separations at relative densities above 5.0 will be outlined and the comparison of results with Clerici’s solution presented.
- Description: E1
- Description: 2003001621
Characterisation of Low-grade Hematite Ore Ultra-fine Size Fraction Particles by Heavy Suspension
- Authors: Koroznikova, Larissa , Begelhole, Jason , McKnight, Stafford
- Date: 2016
- Type: Text , Conference paper
- Relation: Third AusIMM International Geometallurgy Conference 2016 p. 327–334
- Full Text: false
- Reviewed:
Application of high voltage transmission electron microscopy to the study of ultra-fine grained ores
- Authors: McKnight, Stafford
- Date: 2004
- Type: Text , Conference paper
- Relation: Paper presented at The Minerals Industry - Future Directions for New Leaders', Ballarat, Victoria : 21st March, 2004
- Full Text: false
- Reviewed:
- Description: E1
- Description: 2003000706
The biological oxidation of carbonaceous material in the treatment of a refractory gold bearing ore
- Authors: McKnight, Stafford , Hall, Stephen , Rowe, James
- Date: 2004
- Type: Text , Conference paper
- Relation: Paper presented at Refractory Gold Ore Bioxidation 2004, Bendigo, Victoria : 8th November, 2004
- Full Text: false
- Reviewed:
- Description: E1
- Description: 2003000721
Metamorphic style of the Tabberabbera zone, Lachlan Fold Belt
- Authors: Morand, Vincent J , McKnight, Stafford
- Date: 2006
- Type: Text , Conference paper
- Relation: Australian Earth Sciences Symposium, Melbourne 2/07/2006
- Full Text: false
- Description: 2003004226
Hydrothermal insights into the deposition of invisible and visible gold within aresenopyrite
- Authors: Morey, A. , Tomkins, A. , Weinberg, R. , Bierlein, Frank , McKnight, Stafford , Davidson, G.
- Date: 2007
- Type: Text , Conference paper
- Relation: Proceedings of the Ninth Biennial SGA Meeting, Dublin 2007, 20th August, 2007 p. 781-784
- Full Text: false
- Description: By studying backscatter electron (BSE) micrographs, and the major- and trace-element geochemistry of gold bearing arsenopyrite from the late-Archaian Bardoc Tectonic Zone, Western Australia, this study helps constrain the hydrothermal conditions of gold deposition associated with this common ore mineral.
- Description: E1
- Description: 2003005489
Characterization and recovery of gold associated with fine, activated carbon
- Authors: Rowe, James , McKnight, Stafford
- Date: 2009
- Type: Text , Conference paper
- Relation: Paper presented at World Gold Conference 2009, Johannesburg, South Africa : 26th-30th October 2009
- Full Text:
- Description: The attrition of activated carbon, and the loss of gold associated with it, is of significant economic importance to the operation of a CIP/CIL circuit. The focus of this study was on activated carbon recovered from an elution circuit which was deemed too fine for reuse. Results of cyclosizer and laser particle size analysis identified that most of the carbon was contained in the larger size fraction suggesting formation by abrasion. Digestion and AAS analysis of the individual size fractions identified a disproportionate concentration of gold in the finer size fractions which was identified by scanning electron microscopy to be due to the presence of fine metallic gold formed as a result of the acid washing process. Attempts to strip the remaining gold using sodium hydroxide or sodium sulphide based solutions proved unsuccessful due to poor elution efficiencies and re adsorption of gold. Upgrading of the material by froth flotation was also investigated using various conventional flotation reagents which had some success in concentrating the free metallic gold, however, grade and/or recoveries were considered less than desirable. Greater success was ultimately found in the transfer of gold from the fine carbon material onto coarser virgin activated carbon using a caustic cyanide solution. Sodium sulphide, sodium chloride and ammonium chloride based solutions were also trialled but proved less successful owing to their inability to mobilise metallic gold or gold cyanide species. Repetition of the transfer process proved capable of stripping 97% of the gold contained on the carbon fines for a bed volume ratio of 6:1.
- Description: 2003007482