Search Documents

Recently discovered Carboniferous bentonites are variable in charadeI and thickness, but being altered aeolian, ash-fall tuffs, they are probably extensive. Most are the Ca-montmorillonite type without the natural swelling characteristics of the Wyoming deposits, but their situation, thickness, and response to beneficiation through cation exchange may give them some potential as sources of future economic deposits.INTRODUCTIONLoughnan and See (1959) gave an account of bentonites and fuller's earth deposits of New South Wales. The most likely potential industrial sources were those occurring in the uppermost formations of the Newcastle and Singleton Coal Measures (Permian) in the Hunter Valley and deposited during epochs not marked by strong contemporary vulcanicity.One feature of the record of known occurrences at that time was the absence of bentonites from the thick volcanic sequences of the Carboniferous, but since this paper appeared, many bentonite beds have been discovered by the writer in the Carboniferous facies formerly known as the "Kuttung Series".The purpose of this contribution is to report briefly on the occurrence, genesis, mineralogy, and economic potential of these deposits which augment possible sources of bentonite near major industrial centres on the eastern seaboard.The potential world demand for bentonite would increase markedly with the trend to pelletization in the steel industry, if its use in this field became more general. More detailed mineralogical studies will be presented in later publications.STRATIGRAPHIC DISTRIBUTIONBentonite occurs at irregular intervals throughout a thick sequence of dominantly continental, plant bearing strata...

Jan 1, 1965

By S Lal, S Rost, Q Williams, K Collerson

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Shoshonite suite (absarokite-shoshonite-banakite) and adakite-hosted epithermal Au deposits are a feature of circum-Pacific magmatism. Fijian examples include Tavua (Emperor) and Tuvatu on Viti Levu. New discoveries of shoshonite suite and adakite-hosted epithermal Au mineralisation have been made in the southern Yasawa Islands and in central-northern and central-western Viti Levu. The Fijian shoshonites define four NE–SW trending suites. The oldest is the northern 7.9–5.0 Ma Yasawa suite, followed by the 4.7–3.5 Ma Sabeto–Tavua–Rakiraki suite in northern Viti Levu, the 4.7–4.2 Ma Yanuca–Vatulele suite approximately 20 km south of Viti Levu and the 3.4 Ma Astrolabe suite approximately 75 km further south. Shoshonite suite lithologies with 3.8–3.0 Ma ages also occur in the Lomaiviti islands between Vatu-Cake and Moala, to the east of Viti Levu, defining a trend oblique to the NE–SW shoshonite belts. Seatura, a 3.3–2.8 Ma ocean island basalt (OIB) volcano, sits at the northern end of the Lomaiviti trend shoshonites. Trace element/isotopic chemistries indicate that shoshonite arc magma genesis involved the melting of a hydrated supra-subduction zone mantle wedge and also a lower mantle-derived plume (OIB) component. The upwelling plume provided heat for melting and possibly Au enrichment. Accessing the melt generation zone associated with the plume required a slab conduit or window. Such slab windows form by tearing during subduction or occur at slab edges. Adakites form by plume-induced slab melting. The four NE–SW Fijian shoshonite suites are interpreted to occur in back-arc extensional zones above a slab window (tear) that migrated southward during rollback of the New Hebrides–Vanuatu subduction zone. The plume (Seatura OIB) that is interpreted to have caused mantle wedge melting and formation of the Lomaviti trend shoshonites was focused along the interface between the north-dipping Vanuatu–New Hebrides subduction zone and the west-dipping Tonga subduction zone, which we have seismically imaged at approximately 400 km depth. Our model ‘cracks the metallogenetic code’ for shoshonites and adakites and has regional and global implications for Au exploration.CITATION:Collerson, K, Lal, S, Williams, Q and Rost, S, 2015. Cracking the metallogenetic code for Fijian epithermal gold mineralisation , in Proceedings PACRIM 2015 Congress, pp 219–226 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Suddenly, mining has been thrust into the limelight. It has a large image that casts its shadow over New Zealand. Is it any wonder that resistance has heightened and that an almost unprepared populous is currently struggling to protect the very land they hold dear. Next to the atomic bomb, mining has the demonstrated power to massively change the land and its side effects can pollute many miles beyond the operation. During the past year, New Zealand concern over the possible effects of the mining proposals has become acute. This was specially so in the areas of special environmental quality, such as the Coromandel, and here a very unhappy situation has arisen.

Jan 1, 1981

The reactions between molten aluminium and cryoIite have been determined from a material balance of all components involved in the process. The interpretation of results were supported by x-ray diffraction studies of the evolved vapours, quenched electrolyte samples, and side-reaction products.The most important reaction involves the formation of both Na2F (sodium subfluoride) and chiolite in the fused electrolyte. The Na2F accelerates vaporization of the melt. Some AIF (aluminium monofluoride) may also be formed but the proportion of this is much less than for the former subvalent compound.

Jan 1, 1968

Removal of Arsenic in Enargite from Copper Ores by Flotation and Leaching in NaHS Media

Sep 13, 2010

By Arthur A. F, MacKenzie I. H

Copper in zinc/lead sinter charged to the Imperial Smelting Furnace operated by Sulphide Corporation Pty Limited at Cockle Creek, New South Wales, concentrates in a complex lead dross which forms as the bullion is cooled to around 400°C. The 0.35 mm portion of this dross, containing approximatelY 67 per cent of the total copper, is treated via a hydrometallurgical route to produce 5000 tonne/yr of CuSO4 5H2O crystal.Around 3000 tonne/yr of copper-lead dross containing 49 per cent copper is leached at 55°C in continuous leach reactors with ammoniacal ammonium carbonate leach liquors to convert copper to soluble copper amine complexes. Leach ettlciencies of 80-85 per cent are obtained. Leach residues are repulped with ammoniacal liquid diluents from the plant and heated in a four stage steam distillation unit to reduce ammonia levels to between 0.5 and 1.0 g/Iitre. The resultant slurry is directed to an effluent treatment plant for final treatment, and separation and return of solids to the sinter plant.Copper is extracted from leach liquor by solvent extraction techniques based on the use of L1X 54 diluted 3:1 with Shellsol 2046 to give a nominal copper loading of 30 g/litre. The loaded organic is contacted with a sulfuric acid solution of pH 5 to remove the bulk of ammonia and zinc, then stripped at 55°C with a 60 g/Iitre H2SO4 95 g/Iitre copper solution to yield a 15 g/Iitre H2SO4 125 g/Iitre copper solution.This liquor is fed to an adiabatic vacuum crvstalliser operating at 35°C and 5 kPa vacuum where crystals of CuSO4 5H2O are formed. Crystals are separated from mother liquor and washed in a two stage pusher centrifuge, then dried in a hot air rotary drier. The crystal product obtained is of a high chemical purity and readily conforms to both Australian and overseas standards.

Jan 1, 1983

Since the last occasion on which I spoke to you on this subject there has been a considerable increase in the mechanical ventilation of Western Australian mines.The following table compares the figures for 1939 with those of 1941. The type of fan most commonly used is the limit load fan. On account of its higher mechanical efficiency it has very largely superseded the multivane fan with forward curved blades.Two fans of the propeller type are in use and these have given very satisfactory service. This type of fan also has a high mechanical efficiency particularly at the correct duty for maximum efficiency.The maximum efficiencies obtainable from the various types are, for "multivane" 670/0, for "limit load" 75%, and' for aerovane 7810/0.References to propeller fans with variable pitch have appeared in the technical press, but no detailed d~scription has been issued. The advantages of these fans for mine ventilation are not obvious. An aeroplane is required to operate over a wide range of duties, while the speed of the motor for maximum efficiency is pl'actically constant. In such circumstances the propeller can be adapted to the particular work it has to do by varying the pitch of the blades. In a mine the speed of the fan can be varied to suit.the conditions, and it would appear that variable pitch is not necessary while there is a reasonable range of fans to choose from.The question of the correct position for the fan still comes in for considerable discussion. Exhausting fans at the surface have the support of time and custom, and in many cases this represents the only reasonable arrangement. Such fans should be fitted with an evase, especially in the case of fans with a high outlet velocity such as the aerovane types.It is claimed that there are advantages in having the fan at the surface where it is readily available for inspection and maintenance. Experience has shown that these advantages are more apparent than real. Fans will run for long periods with no attention other than occasional greasing and cleaning, and modern electric motors will run without attention for very long periods.In some instances the expense of a power cable to take current to the fan may be saved by placing it on the surface, but in the majority of cases...

Jan 1, 1941

By A H. Clemens, T A. Moore

This paper discusses a number of technical issues related to marketing coal. It outlines how the results of research undertaken in New Zealand and overseas can help producers address a range of technical factors that impact on production costs and marketability. The paper also discusses trends in coal utilisation for power generation and how new technologies may require coal with different characteristics. Research and development into options for CO2 sequestration are discussed including carbon storage in forests, and removal of CO2 from flue or fuel gas in power stations, and its disposal.

Jan 1, 1997

By P Goblet, S A. Séguret, E Cordier, A Galli

In salar-type deposits, lithium grades can be measured by bailers introduced at different elevations in the drill holes at locations where, later, the brine will be pumped out to recover the metal. When they are duplicated, these a priori rudimentary measurements may show large differences without indicating whether this is due to the procedure itself or to some physical causes linked to the dynamic behaviour of the salar (seasonality, rainfall, underground flow etc). In the reservoir presented in the paper, the problem is complicated by the double lack of stationarity of the lithium grades: the grades not only increase importantly with the depth but at the same time their fluctuations decrease, making it necessary to use non-stationary geostatistical techniques to simulate them. Reservoir simulation is developed in two steps: first, geostatistical simulations of the lithium grade create possible realisations of the reservoir; then, each geostatistical simulation is followed by a pumping simulation that calculates, at each drill hole of a given extraction scenario, the lithium produced each year over 40 years. For the set of 100 simulations produced in this way, a scenario reduction is made to choose the five most representative simulations where more complex calculations will be carried out (for example, changing hydrogeological parameters such as porosity and permeability, or the elevation of the filters, the number and the location of the pumping and the reinjection drill holes etc). The paper first presents an analysis of the geostatistical model sensitivity to the grade uncertainty when measured by bailer. Among the 100 measurements at our disposal covering the future production domain, 50 per cent are duplicates measured at the same place but at different times. They are randomly sampled to produce five subsets of 75 values, which will constitute the future 3D conditioning points for the geostatistical analysis and the simulations. For each subset, trend, standard deviation and variogram models are fitted, leading to five sets of 20 geostatistical simulations of grades. In this way, the reliability of the different parameters involved in the procedure is evaluated, as well as its impact on the pumping results. Then, a reconciliation study is conducted between the non-stationary nugget effects encountered in the 3D variograms of the lithium grade and a pure statistical analysis of 25 duplicates measured at different locations and/or different times. The result is that if the nugget effect reaches 20 per cent, which is the case of three conditioning subsets out of five, the reconciliation is good and the nugget effect of the variogram model represents the bailer uncertainty, ie the measurement error. Since the geostatistical simulation incorporates a nugget effect, it handles the bailer uncertainty and the impact on the produced metal is included in the evaluation. The final conclusion is that, after the hydrogeological pumping simulations, the initial differences between the five geostatistical models do not influence the final results: lithium grades measured by bailers can lead to a robust evaluation of the extractable resources, a conclusion that conflicts with conventional wisdom.CITATION:Séguret, S A, Goblet, P, Cordier, E and Galli, A, 2017. Bailer uncertainty evaluation in a lithium salar deposit, in Proceedings Eighth World Conference on Sampling and Blending , pp 395–402 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

This paper deals with the application of table flotation to two unusual mineral dressing problems. Both problems involved the removal of interfering minerals at sizes too coarse to normal froth flotation.The first problem was the removal of arsenical minerals from Broken Hill gravity concentrates without further size reduction. Table flotation without grinding of the original concentrates gave almost complete rejection of the arsenic from the concentrates. A typical test result was a reduction of arsenic in jig concentrate from 0.75% arsenic to 0.007% arsenic.The second problem was to develop a method to produce a high grade calcium carbonate concentrate from coastal dune sands containing about 10% silica and about 80% calcium carbonate. The sands were about 30 mesh British Standard Screen (B.S.S.), and for economic and other reasons it was stipulated that the separation be made without grinding. Again, table flotation gave excellent results. A concentrate was produced containing 99.62% acid soluble material, representing a recovery of 98.69% of the calcium carbonate in the feed with a rejection of 96.44% of the silica.The investigations' were carried out at the Kalgoorlie Metallurgical Laboratory, under the Department of Mines...

Jan 1, 1954

Fire suppression systems are now recognised by both NFPA 502 and PIARC as legitimate tools for both life protection and asset protection. The effectiveness of these tools for life protection demands extremely rapid and accurate incident detection coupled with rapid response. This rapid response must be integrated with other emergency systems such as emergency ventilation. The March 2007 fatal Burnley Tunnel incident in Australia graphically illustrates the potential of effectively integrated fixed suppression systems to protect people from harm and save infrastructure from damage. Despite the raft of technology available in that instance to the operator it was the human operatorÆs ability to effectively control the emergency equipment and not the equipment itself which so positively influenced the threat to life and property.

Jan 1, 2008

By P Stephenson, G Mosher, M Berry, C Arnold, P Stoker

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Globally, private minerals companies considering the transition to a public company and entrepreneurs looking to create a new public company through, for example, an initial public offering or by a reverse takeover have many options. For companies with assets around the Pacific Rim, there are arguably five key stock/securities exchanges that actively promote international minerals company listings, and these are located in Australia, Canada, Hong Kong, Singapore and the United Kingdom.Listing on any of these exchanges requires a range of technical, commercial, financial and legal documentation. Each exchange has specific rules and requirements for technical documentation to support the listing process. Once listed, each exchange also has specific rules for technical information to meet ongoing compliance requirements. The nature and detail of this documentation differs for the five exchanges.This paper presents statistics on the minerals company listings on each exchange and provides an overview of the technical documentation required to prepare for an initial listing and ongoing compliance.CITATION:Berry, M, Stoker, P, Stephenson, P, Arnold, C and Mosher, G, 2015. Technical considerations of public listing and ongoing compliance for minerals companies , in Proceedings PACRIM 2015 Congress, pp 101–108 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Silica reacts with cryolite at 1010°C in two stages. The first stage is the formation of a sodium aluminosilicate of composition consistent with the mineral jadeite (Na20.AI20s.4Si02). The formation proceeds by atleast two different reactions. Formation of alumina or an aluminosilicate proceeds to its limiting value in the first 30 min while the formation of jadeite proceeds at a steady rate until quantitative conversion is achieved after 150 min. The net overall reaction can be expressed by the equation 6 Si02+2 Na3AlF6? (Na20.AI20s.4Si02) +2 SiF4 +4NaF.The second stage involves a slow reaction that proceeds with the evolution of a little SiF4, The net result is the formation of sodium aluminosilicates that are soluble in 30 per cent AlCIs-HCI solutions. While this could be explained by disproportionation of jadeite to form albite (Na20.Al203.6Si02) and nepheline (Na20. AI203.2Si02), it is more likely that it is due to further but limited reaction between the oxides and fiuoroaluminates.

Jan 1, 1972

When we are beset with the economic problems the world faces today, we are always inclined to look at the shorter term future. Today I would like to take a long-term view of our industry, project historical demands for our products into the future and discuss opportunities for our members. Perhaps we could firstly look at the long-term demand trends for our metals. If I tend to use non ferrous metals as a basis for my figures it is because this data is more readily available to me. I am sure that most other products of our industry show similar trends.

Jan 1, 1992

Experimental Study of Ore Characterisation Methods for AG/SAG Mills Mining companies have long recognised the importance of ore breakage characterisation in design and optimisation of their crushing and grinding circuits. In one of the industry standard methods relevant to AG/SAG milling, ore is characterised using mainly high energy single impact tests. However recent DEM studies have suggested that breakage in AG/SAG mills is mainly due to low energy repetitive (or multiple) collisions rather than single high energy impacts. Hence a study was initiated at the JKMRC to investigate the behaviour of ores under such conditions. Carefully designed experiments have been performed using two laboratory mill sizes (0.6 m and 1.1 m diameter) to mimic the reported low energy repetitive impact breakage under low load conditions. The breakage characterisation parameters derived from standard high energy single impact tests on the same ores was then used to predict the low energy repetitive impact breakage. Significant bias was found in the simulations which clearly warranted further investigation. The extensive experimental program which followed employed three separate methods: the JKRBT (JK Rotary Breakage Tester) for high energy single impact and low energy repetitive impacts, gravity drops for low energy repetitive impacts, and laboratory mills to provide an extended number of low energy repetitive impacts. The breakage energies associated with these experiments were accurately measured with a high speed video camera. Two breakage indices, the degree of breakage (t10) and the breakage probability (S) were used to describe the breakage test results. This paper summarises the major results from this experimental study, which has facilitated the development of a new breakage characterization method relevant to AG/SAG mill modelling.

Sep 13, 2010

By Rayner J. G, Leckie J. F, Moorehead C. F

The Coronation Hill gold-platinum-palladium prospect is located in the valley of the South Alligator River (latitude 13'35'S, longitude 132'36'E), about 80 kilometres east of Pine Creek in the Northern Territory. Coronation Hill was one of thirteen sites in the South Alligator Valley at which uranium was mined between 1955 and 1964 after initial discovery by the Bureau of Mineral Resources in 1953. Most of the mines were operated by United Uranium No Liability. The Sleisbeck mine 25 kilometres south of Coronation Hill was operated by North Australian Uranium Corporation and the group of mines at Rockhole about 20 kilometres to the north-west of Coronation Hill was operated by South Alligator Uranium No Liability. The uranium mine at Coronation Hill produced about 26000 tonnes of ore averaging 2.6 kg/t U308 with an estimated average gold grade of 10.4 g/ gold. Gold was commonly associated with the uranium mineralisation and was recovered at the gravity treatment plant at El Sherana. Gold was also recovered in 1986 by Pacific Gold Mines Limited by treating the tailings from the Moline and Rockhole uranium leach plants at a CIP plant at Moline. With the completion of uranium contracts in 1964 mining in the South Alligator Valley ceased. Exploration for uranium continued in the area during the 1960s and 1970s with no success. The Coronation Hill Joint Venture (BHP Gold Mines Limited 45 per cent, Pioneer Minerals (Gold) Pry Ltd 45 per cent, Notgold Limited 10 per cent)carried out the first exploration specifically targetted at gold in 1984 with the drilling of five vertical drill holes which indicated high potential for a substantial gold resource at Coronation Hill with no associated uranium. The Joint Venture has sub- sequently drilled about 25000 metres of diamond drill holes at Coronation Hill alone. Analytical results from 1985 drilling established that platinum and palladium were associated with gold. An indicated resource of 3.49Mt at 5.12g/t Au, 0.21g/t Pt and 0.56g/t Pd has been calculated using a lg/t Au cut off.

Jan 1, 1991

Background information, formulae and a systematic set of procedures for estimating capital and operating costs for open pit mining equipment are presented in this paper. Firstly, equipment capital costs are required. These can be obtained from either suppliers, contractors or from first principles. The equipment is then divided into cost elements. Typically these are fuel and power requirements, spare parts consumption, wear items such as tyres, teeth and drill bits and finally repair and operating labour requirements. By consideration of the cost and life of each element a base cost can be derived. The base cost is then adjusted to suit specific site conditions such as the proximity to spare parts suppliers, the duty or ground conditions and the management and operator skills specific to the site. Hence, the same item of equipment can be costed to reflect different operations. Included are tables and data for typical plant items. Several examples are also given to illustrate the methodology being presented. The intention is to provide a set of procedures to allow costs to be built up from base level in a systematic and repeatable way. Applications for these costs include feasibility studies, budgetting and data for economic analyses.

Jan 1, 1990

Maintaining high carbon activity is vital to the efficiency of any Carbon-In-Leach or Carbon-In-Pulp process. Reduced activity can lead to longer residence times or gold losses in the tails. Regenerated carbon from the CIL circuit at Macraes Gold Mine was analysed for kinetic activity and composition over a 15 month period. An increase in kinetic activity during the time period was recorded, which was linked to reduced Na and Ca loadings. A laboratory simulation of the loading, stripping and regeneration of gold was developed and tested. Kinetic activities were obtained for synthetically fouled carbons following three circuits of the laboratory simulation. It was shown the competitive gold adsorption ability of xanthate fouled carbon (previously reported as a serious deactivator) could be significantly recovered following effective thermal regeneration. This ability was maintained in a subsequent circuit loading.

Jan 1, 1993

By A A. Ndiaye, A Galli

In a companion paper on current hedging practices in the mining industry (Armstrong et al, 2009) we showed that contrary to popular belief, mining groups are still using financial derivatives to hedge against foreign exchange risk and interest rate risk, and more recently against adverse changes in energy prices, notably the oil price. This paper presents a case study on a hypothetical gold mine to illustrate the impact that hedging policies could have on its profitability by reducing the downside risk due to adverse changes in the exchange rate and increases in fuel prices. The characteristics of the hypothetical mine have been set to reproduce those of a real gold deposit, the Kisladag mine that is currently being exploited by open pit methods in Turkey. This mine was selected because its feasibility study was available to the public. Geostatistical simulations are used to reproduce the inherent uncertainty on the recoverable reserves û stochastic simulations are used to generate the variability of the other three key sources of uncertainty: the gold price, the cost of energy and the exchange rate. A simple strategy based on straightforward vanilla options (puts and calls) was developed for hedging the last two risks, on the assumption that the company sells its production at the prevailing spot price.

Jan 1, 2009

An important consideration in any mining operation is waste disposal management. Tailings management at Macraes gold mine allows for the disposal of tailings into fully engineered embankment dams and overburden material to be incorporated as construction material into those embankment dams. This paper outlines the current tailings management practices.

Jan 1, 1992