- Authors: Carey, Stephen
- Date: 2007
- Type: Text , Journal article
- Relation: AusIMM Bulletin Vol. , no. 6 (2007), p. 81-82
- Full Text: false
- Reviewed:
- Description: The University of Ballarat organizes international excursion for its undergraduate geology students to provide them an opportunity to learn and gain international experiences of geology. The university previously organized an excursion of New Zealand in November-December 2006 to provide students knowledge about plate boundary and gold mineralization. The excursion was sponsored by Oxiana Limited, the Bicentennial Gold 88 Endowment, Newmont Australia Limited, and Castlemaine Goldfields Ltd. The excursion was planned for 17 days and visit to the Taupo Volcanic Zone, Kaikoura, The Waipara, Mt Cook and the Tasman Glacier, Macraes gold mine, Otago's silcretes, Queenstowm, and Milford Sound. More information about 2006-excursion can be found on the website at http://www.ausimm.com.au/main/education/award-bice-gold-php.
The use of low-toxic heavy suspensions in mineral sands evaluation and zircon fractionation
- Koroznikova, Larissa, Klutke, Cameron, McKnight, Stafford, Hall, Stephen
- Authors: Koroznikova, Larissa , Klutke, Cameron , McKnight, Stafford , Hall, Stephen
- Date: 2008
- Type: Text , Journal article
- Relation: Journal of The South African Institute of Mining and Metallurgy Vol. 108, no. 1 (2008), p. 25-33
- Full Text:
- Reviewed:
- Description: This paper outlines a simple methodology for mineral characterization, developed as part of the Australian Mineral Industry Research Association (AMIRA) managed research project P777 'The Development of Heavy Suspension Techniques for High Density Separations (Replacement of Clerici's Solution)'. The project was sponsored by De Beers, Rio Tinto and Iluka Resources. Heavy mineral characterization of samples arising from exploration, mining or metallurgical processes is frequently conducted using laboratory heavy liquid analysis. 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 utilized at relative densities (RD) up to 3.0. Beyond this value organic liquids can be used; however, this presents significant health and safety hazards. Diiodomethane (methylene iodide) having a relative density of 3.31 is commonly used. 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. For the characterization of the heavy components of mineral sand deposits (e.g. anatase RD 3.9, rutile RD 4.2, ilmenite RD 4.4-4.7 and zircon RD 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 few laboratories worldwide, with costs reflecting the chemical costs, infrastructure costs and health and safety regimes (e.g. blood testing of exposed staff). A simple laboratory technique of density fractionation has been developed, employing suspensions of fine tungsten carbide particles in lithium heteropolytungstates solutions, that can replace Clerici's solution in the evaluation of fine mineral sands samples (e.g. -250 +150 microns). The developing methodology that can achieve low-cost, low-toxic separations at relative densities above 4.0 is outlined and the comparison of results with Clerici's solution presented. In addition, preliminary work on density fractionation of zircon samples is presented. Zircon fractionation relates to their inclusion, radionuclide content and metamictization. © The Southern African Institute of Mining and Metallurgy, 2008.
- Description: C1
- Authors: Koroznikova, Larissa , Klutke, Cameron , McKnight, Stafford , Hall, Stephen
- Date: 2008
- Type: Text , Journal article
- Relation: Journal of The South African Institute of Mining and Metallurgy Vol. 108, no. 1 (2008), p. 25-33
- Full Text:
- Reviewed:
- Description: This paper outlines a simple methodology for mineral characterization, developed as part of the Australian Mineral Industry Research Association (AMIRA) managed research project P777 'The Development of Heavy Suspension Techniques for High Density Separations (Replacement of Clerici's Solution)'. The project was sponsored by De Beers, Rio Tinto and Iluka Resources. Heavy mineral characterization of samples arising from exploration, mining or metallurgical processes is frequently conducted using laboratory heavy liquid analysis. 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 utilized at relative densities (RD) up to 3.0. Beyond this value organic liquids can be used; however, this presents significant health and safety hazards. Diiodomethane (methylene iodide) having a relative density of 3.31 is commonly used. 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. For the characterization of the heavy components of mineral sand deposits (e.g. anatase RD 3.9, rutile RD 4.2, ilmenite RD 4.4-4.7 and zircon RD 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 few laboratories worldwide, with costs reflecting the chemical costs, infrastructure costs and health and safety regimes (e.g. blood testing of exposed staff). A simple laboratory technique of density fractionation has been developed, employing suspensions of fine tungsten carbide particles in lithium heteropolytungstates solutions, that can replace Clerici's solution in the evaluation of fine mineral sands samples (e.g. -250 +150 microns). The developing methodology that can achieve low-cost, low-toxic separations at relative densities above 4.0 is outlined and the comparison of results with Clerici's solution presented. In addition, preliminary work on density fractionation of zircon samples is presented. Zircon fractionation relates to their inclusion, radionuclide content and metamictization. © The Southern African Institute of Mining and Metallurgy, 2008.
- Description: C1
Bulk sampling of complex gold deposits - material characterisation and program design and management
- Dominy, Simon, Platten, Ian, Xie, Y.
- Authors: Dominy, Simon , Platten, Ian , Xie, Y.
- Date: 2008
- Type: Text , Conference paper
- Relation: Australasian Institute of Mining and Metallurgy Publication Series, Perth, WA p. 41-57
- Full Text: false
- Description: Complex gold deposits are generally characterised by variable geometries, strong structural controls on grade distribution and a high-nugget effect. The use of diamond drilling and fire assays in this environment often results in an understatement of grade. Bulk samples are likely to be the closest estimators of true grade, and may be required to evaluate geological/grade risk during resource estimation/feasibility studies. Any bulk sampling program requires appropriate planning and implementation. The planning stage should attempt to delimit the extent and nature of mineralisation; characterise mineralogy and metallurgical properties of the ore; and define bulk sample size and how it will be sampled/processed. The approach to sample processing will be governed by the results of metallurgical testing and geological knowledge. Careful design of sampling protocols must be undertaken through material characterisation, understanding of gold particle sizing and the application of Gy's Sampling Theory.
Electrochemical studies of organic compounds in zinc electrowinning circuits
- Authors: Vawdrey, Peter
- Date: 1986
- Type: Text , Thesis , Masters
- Full Text:
- Description: Most of Australia's zinc production is by the electrolytic zinc process, in which zinc is electrowon from an acid sulphate solution. The process is known to be exceptionally sensitive to the presence of trace impurities. At the Electrolytic Zinc plant (Risdon, Tasmania), isobenzofuranone (pthalide) has been detected in the electrowinning circuit, and found in higher concentrations during efficiency slumps. It was found that di-2-ethylhexyphthalate, (present in the liners and plastics used in the electrowinning circuit), is reduced to isobenzofuranone under the electrolysis conditions employed. In addition, an investigation involved a constant current electrolysis of a synthetic zinc electrolyte, as identified an additional pathway for the productionof isobenzofuranone. 2-Naphthol, added to the electrolysis circuit for current efficiency purposes, is also a major precursor of isobenzofuranone. 2-Napthol and possibly 1-nitroso-2-napthol can be oxidized to pthalic acid, either at a lead anode or via anode oxidation productions, and the phthalic acid produced can be reduced to isobenzofuranone at a zinc cathode. In addition, it was found that isobenzofurane is further reduced at the potential of zinc deposition to ultimately yield 2-methylbenzaldehyde. This compound, which has also been detected in Risdon plant electrolytes, is also toxic in the zince electrowinning circuit. The compound 2-methylabenzyl alcohol has also been detected via GLC examination of Risdon plant liquors. However, this compound was not detected in the present investigation, and thus no explanation can be offered for its presence in plant electrolytes. The toxicity of zinc electrolyte impurities on current efficiency was determined by a cyclic voltammetric technique. The results of this investigation indicate that the presence of isobenzofuranone and 2-methylbenzaldehyde can significantly lower current effciency, and the compounds phthalic acid and 2-methylbenzyl alcohol also lower efficiency.
- Description: Masters Degree in Applied Science
- Authors: Vawdrey, Peter
- Date: 1986
- Type: Text , Thesis , Masters
- Full Text:
- Description: Most of Australia's zinc production is by the electrolytic zinc process, in which zinc is electrowon from an acid sulphate solution. The process is known to be exceptionally sensitive to the presence of trace impurities. At the Electrolytic Zinc plant (Risdon, Tasmania), isobenzofuranone (pthalide) has been detected in the electrowinning circuit, and found in higher concentrations during efficiency slumps. It was found that di-2-ethylhexyphthalate, (present in the liners and plastics used in the electrowinning circuit), is reduced to isobenzofuranone under the electrolysis conditions employed. In addition, an investigation involved a constant current electrolysis of a synthetic zinc electrolyte, as identified an additional pathway for the productionof isobenzofuranone. 2-Naphthol, added to the electrolysis circuit for current efficiency purposes, is also a major precursor of isobenzofuranone. 2-Napthol and possibly 1-nitroso-2-napthol can be oxidized to pthalic acid, either at a lead anode or via anode oxidation productions, and the phthalic acid produced can be reduced to isobenzofuranone at a zinc cathode. In addition, it was found that isobenzofurane is further reduced at the potential of zinc deposition to ultimately yield 2-methylbenzaldehyde. This compound, which has also been detected in Risdon plant electrolytes, is also toxic in the zince electrowinning circuit. The compound 2-methylabenzyl alcohol has also been detected via GLC examination of Risdon plant liquors. However, this compound was not detected in the present investigation, and thus no explanation can be offered for its presence in plant electrolytes. The toxicity of zinc electrolyte impurities on current efficiency was determined by a cyclic voltammetric technique. The results of this investigation indicate that the presence of isobenzofuranone and 2-methylbenzaldehyde can significantly lower current effciency, and the compounds phthalic acid and 2-methylbenzyl alcohol also lower efficiency.
- Description: Masters Degree in Applied Science
Copper loss into rotary holding furnace slag
- Authors: Burrows, Alistair
- Date: 1999
- Type: Text , Thesis , Masters
- Full Text: false
- Description: The Rotary Holding Furnace (RHF) is used in combination with the Copper Isasmelt Furnace as a settling vessel. This study investigated the phenomenon of entrained copper losses into RHF slag. Research work was conducted by laboratory-scale flow modelling, and by plant sampling of the RHF at Mount Isa Mines Limited. Laboratory fold modelling was conducted to measure the residence time distribution of a simulated slag layer in a l;'0 -scale model of the RHF. A novel technique, involving a copper tracer dissolved in an organic solvent extractant solution, was used for these experiments. Plant trials complemented the laboratory work with a variety of slag sampling campaigns. Residence time tests were also attempted on the RHF slag. In combination, the laboratory and plant scale experimental work performed in this investigation helped to highlight some likely causes of entrained copper loss in the RHF. Laboratory cold modelling of the RHF suggests that the depth of the upper liquid layer is • likely to affect the fluid flow patterns, and therefore the residence time distribution expected of the layer. A stratification of the flow was prevalent in thick upper liquid layers, but absent when thin upper layers were used. A stagnant region within the upper layer0 0f the model was identified. The introduction of gas injection through porous plugs caused mixing within the upper liquid layer. Stable waves were produced at the liquid liquid interfate. ' .. Plant experiments were constrained by commercial operating schedules. Several parameters were investigated during two different periods of experimental work. Granulated slag sampling indicated a link between the duration of continuous slag discharge and the copper content of the slag. Evidence was found that suggests the presence of interfacial waves.
- Description: Doctor of Philosophy
- Authors: Burrows, Alistair
- Date: 1999
- Type: Text , Thesis , Masters
- Full Text: false
- Description: The Rotary Holding Furnace (RHF) is used in combination with the Copper Isasmelt Furnace as a settling vessel. This study investigated the phenomenon of entrained copper losses into RHF slag. Research work was conducted by laboratory-scale flow modelling, and by plant sampling of the RHF at Mount Isa Mines Limited. Laboratory fold modelling was conducted to measure the residence time distribution of a simulated slag layer in a l;'0 -scale model of the RHF. A novel technique, involving a copper tracer dissolved in an organic solvent extractant solution, was used for these experiments. Plant trials complemented the laboratory work with a variety of slag sampling campaigns. Residence time tests were also attempted on the RHF slag. In combination, the laboratory and plant scale experimental work performed in this investigation helped to highlight some likely causes of entrained copper loss in the RHF. Laboratory cold modelling of the RHF suggests that the depth of the upper liquid layer is • likely to affect the fluid flow patterns, and therefore the residence time distribution expected of the layer. A stratification of the flow was prevalent in thick upper liquid layers, but absent when thin upper layers were used. A stagnant region within the upper layer0 0f the model was identified. The introduction of gas injection through porous plugs caused mixing within the upper liquid layer. Stable waves were produced at the liquid liquid interfate. ' .. Plant experiments were constrained by commercial operating schedules. Several parameters were investigated during two different periods of experimental work. Granulated slag sampling indicated a link between the duration of continuous slag discharge and the copper content of the slag. Evidence was found that suggests the presence of interfacial waves.
- Description: Doctor of Philosophy
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