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By Sparrow G. J

In a recently completed AMIRA project, 20 samples were searched for gold mineralisation using the automated location facility (ALF) for rare phases on a scanning electron microscope in the CSIRO Division of Mineral Products, Melbourne. The samples were submitted by mining companies in Australia, and Papua New Guinea, and included crushed ore samples, cyclone overflow and underflow products, a flotation concentrate, and 12 tailing samples. Their gold contents ranged from 600 to 0.2 g/t An. Native gold and gold minerals including a gold telluride, gold-silver tellurides, and a gold bismuth mineral, were located in the samples as free grains and associated with other minerals such as pyrite, magnetite, hematite, ankerite, copper sulphides, silicate minerals, and quartz. In the highest grade samples, both micron sized and 200 ¦m grains of gold were found with ALF. It would be difficult to locate such d wide size range of gold in a manual search. Gold mineralisation was located in the tailing samples assaying 0.4 g/t An and higher. In several tailing samples coarse grains of native gold over 40 p.m in size were located. One grain was estimated to have contributed 40 per cent of the gold in the sample. As well as locating gold mineralisation, the ALF examination resulted in the identification of uranium, mercury, and bismuth minerals in the samples. Knowledge of the distribution of these minerals in processing streams could be important in the operation of a concentrator.

Jan 1, 1992

By Sullivan T. D, Lohe E. M

Geological structure is one of the main controls on ground conditions within mining. It has a significant impact on the mining conditions and productivity of coal mines within the Sydney - Bowen Basin. The three main types of faults common to this region, normal, reverse and strike-slip systems, each present distinct challenges to mining. These systems effect a wide range of geotechnical and mining conditions within the mines. These include coal quality, strata stability, goat and caving behaviour, productivity and maintenance schedules of mining equipment, mine design and mine-site stress fields. A better understanding of the regional, local and mine-scale structural setting, timing relationships of structural events and the mechanisms of fault formation will greatly aid industry's push for greater productivity and competitiveness.

Jan 1, 1991

By T Ye Koltunova an, L A. Otrozhdyonnova

This paper presents the results of studies on the development of an efficient non-cyanide technology for processing massive, finely disseminated, copper-zinc ores of the Urals deposits. Copper is mainly represented by chalcopyrite and zinc û by sphalerite. The main ore mineral is pyrite, with its content in ores varying from 50 to 80 per cent. At the present time, separation of copper concentrate at the Urals concentrating plants is achieved in a lime medium by non-cyanide technology using sodium sulfide and zinc sulfite as depressors of zinc and iron sulfides and butyl xanthate as the collector. Copper content in copper concentrates amounts to 15 - 17 per cent; considerable losses of zinc are associated with copper concentrate and final tailings. Various collectors were tested during the studies: xanthates and aerofloats with different lengths of hydrocarbon radicals, thionocarbamates, Aerofine 3418A of Cytec Industries, reagent S-703G of Mineral Reagents Int, and modifiers û sulfur dioxide, sodium sulfide and zinc sulfite, with a pH of the medium varying from 5 to 12. Optimum results of copper concentrate separation were achieved in a weakly acidic medium using S-703G as the collector and sulfur dioxide and zinc sulfite as modifiers. The copper content in the copper concentrate was increased by 4.8 per cent. Total copper recovery into the copper concentrate and zinc recovery into the zinc concentrate exceeded five per cent.

Jan 1, 2005

By Lock PR

The Silver Swan nickel mine is located at the Black Swan Nickel Project, 53 kin north east of Kalgoorlie, Western Australia. The Silver Swan orebody is a massive sulphide nickel deposit dipping 70¦ east with an average in situ grade of 14 per cent. Mining of the massive orebody is by Mechanised Ramp Cut and Fill (MRCF). A mining recovery of 98 per cent and minimising dilution are primary goals in extracting the high-grade ore. Placing a distinguishable marker bed (working platform) on rock fill was identified as a key method to achieving these goals. Gravel from a pit located onsite was considered the most suitable material for the marker beds. Research undertaken to design the marker beds using the gravel revealed conventional methods used in mining would not suffice, but that road stabilisation methods could be a viable alternative. Trials used a road recycler to mix cement and gravel in situ and several test beds were constructed on the surface to determine the final design. The trials attempted to replicate a marker bed's life cycle of construction and placement and mucking of ore from the marker bed.

Jan 1, 1998

By Torckler L, Brathwaite R. L

At Neavesville gold-silver (electrum) mineralization occurs in steeply-dipping zones of intense fracturing, brecciation and quartz veining within rhyolitic pyroclastics, carbohaceous shales and andesites. Hydro- thermal alteration extends over an area of greater than 3 by 1.5 km. In rhyolitic tuffs, highly silicified zones containing quartz- adularia-illite assemblages are flanked by less silicified assemblages composed of albite, illite-montmorillonite and chlorite. The mineralogy ana sequence of alteration are comparable with the alteration zones which envelop the steam-producing fissures of the active Wairakei and Broadlands geothermal fields. Primary fluid inclusions in quartz from five fissure veins in the Neavesville field show maximum homogenisation temperatures ranging from 220 - 260¦C and salinities of 0.0 - 1.1 wt. % NaCl equivalent, which cover a similar range to actual measured temperatures and salinities in geothermal fluids at Wairakei aria riroaolan¦s. The age of the rhyolitic pyroclastics and related alteration and mineralization is probably Pliocene and Neavesville therefore represents a fossil geothermal system.

Jan 1, 1980

Results from current NERDDC funded research into the geotechnology of highwall trench mining methods have clear implications for mine planners in the areas of blast design, trench shape, location of the surcharge spoil and remnant coal pillar design.Adoption of successful smooth wall blasting techniques not only removes safety hazards from the trench face, but limits development of bedding partings at the seam contacts that interrupt the smooth transition of stress across the coal seam.

Jan 1, 1992

The continuous casting of zinc alloys has been of fundamental importance for many years in the production of a number of products, including sheet for architectural applications, battery cans for dry cells and wire for metallising. The intrinsic benefits of continuous casting, including efficiency and high tonnage capability, uniformity of metallurgical structure and properties, and absence of voids and other defects, have contributed to the success of these products. Less well known, but of growing importance, is the more recent application of continuous casting technology to the production of zinc alloy bar stock products, including bearing stock, machining bar stock, forging stock and cathodic protection anodes. A wide range of zinc alloys are now continuously cast in a variety of cross sectional shapes and sizes to suit the diverse characteristics of these products. Of particular significance are the introduction of hollow zinc-aluminum bearing stock, and the availability of zinc alloy machining bar stock for hydraulic applications and for producing prototypes of zinc alloy pressure die castings. In addition to the traditional benefits, continuous casting provides special properties which are important in the application of these bar stock products. The list of successful applications of continuously cast zinc alloy bar stock is growing rapidly, and the market potential for resultant new zinc applications appears to be significant.

Jan 1, 1993

By Knijnikov M, Cameron D

Coal Quality management and the control of the flow of coal through complex mining preparation and transport phases of standard mining operations has assumed greater importance over recent years.

Jan 1, 1998

By D K. Weatherley, A N. Mainza, I Govender, L M. Tavares, M S. Powell

It is understood that rocks do not instantaneously transport along a grinding mill and are consequently not perfectly mixed, but this is conveniently overlooked in mill modelling. A lack of understanding of the transport phenomenon and the difficulty of modelling realistic transport in a complex tumbling system, contribute to this. Visual observation of segregation in AG and SAG mills and measured lag time of mill response to changes in feed provide evidence of the influence of axial transport within mills. Incorporating this lag in dynamic models should underpin dynamic simulation of milling circuits for design and for model-based control. Limitations and errors in predicting the influence of increased power via mill length versus diameter, inability to predict pebble production, and a lack of the differential in residence time across rock sizes and competences, all contribute to inadequate design prediction that can be especially acute for large Autogenous mills. Examples of dramatically under – and overloaded pebble regrind circuits and the inability to predict pebble load in AG milling discouraging the application of this energy-efficient option, point to the need for predictive modelling of breakage by competence linked to transport through and out of mills. Incorporating progress in granular flow and mixing, coupled to computational advances enable models to be based on complex breakage and transport models at high spatial resolution. This allows mechanistic models to simulate thousands of times faster than real time, opening the door to more accurate mill design, including dynamics in process simulation and to live simulation for process control – all with advanced mechanistic models. The value of grasping this opportunity is not easily refuted.

Aug 24, 2022

By Richards RG, Cross MS

The development of alluvial mining, processing systems and associated gravity separation technology over the last 30 years is largely linked to the mineral sands industry. Attention has been focussed on Australia in these areas of mineral resource development and technological Advancement.

Jan 1, 1986

By P Church

What is the best method of splitting a sample from a reverse circulation drill rig? How important is it to obtain a correctly split sample? What is the impact of an incorrectly split sample? These are just a few of many questions asked daily in the mining industry with regard to sampling. Modern sampling theory is well described in the literature in texts and is taught in short courses throughout the world, however little has been published on the relative performance of sample splitting devices used in the field. This paper compares the performance of the Jones tiered riffle splitter with a cone splitter manufactured by SGS Metal Craft in Western Australia. The testwork was carried out at AnglogoldÆs Sunrise Dam Gold Mine, 55 km south of Laverton in Western Australia. Mineralisation at Sunrise Dam is hosted in a structurally complex framework of shear zones with dips that range from steep (70¦) to shallow (25¦). The deposit is characterised by significant amounts of coarse gold, which presents a challenge in sampling, analysis and grade estimation. The three major areas where sampling errors can occur are in drilling, sampling, sample preparation and analysis. Sampling errors attributable to drilling and sample preparation often far outweigh the errors made at other stages in the process, however historically most effort to identify sampling errors has concentrated on the laboratory and analytical procedures. Splitter design and cleanliness can have a large impact on sample collection and preparation. Splitter performance was tested with respect to sample weights, particle size distribution, and gold grade consistency. The aim was to determine if each particle has an equal probability of being sampled, the resulting sample has integrity, and if any segregation problems occurred. The cone splitter was found to provide the best split in terms of particle size distribution, with no apparent size bias. Duplicate samples had more comparable masses than those provided by the riffle splitter. Most importantly, the cone splitter gave less grade variability between duplicate samples than the riffle splitter. Testwork also confirmed that, like the riffle splitter, the cone splitter must be oriented vertically and the design of the rig or cone splitter trailer should accommodate this requirement.

Jan 1, 2003

By P Breuer, D J. Robinson, A McFarlane, L L. Kuhar

Increasing global demand for commodity metals and capital and the greater operating costs of mining and metal production present significant challenges for the metals mining industry. Current conventional technologies may not be feasible for processing deposits of declining grade, challenging mineralogy or those that occur at increasingly greater depths. To overcome these issues, the development of a step-change technology such as in situ recovery (ISR), which reduces mining and avoids milling costs, may be vital in ensuring future economic metal production. ISR has been used extensively to treat porous soft rock deposits such as the water-soluble salts, sylvite and halite. Although ISR has typically been used for mining conventionally uneconomic uranium ores, it has also been used less frequently for the treatment of other restricted permeability hard rock deposits, such as those containing copper and gold. The reason for the limited uptake of the technology for hard rock mineralisations is primarily due to low natural rock porosity and permeability and hence poor response to available lixiviant. However, additional challenges include solution containment, management of groundwater and regulatory, ecological and societal requirements and expectations. CSIRO has focused on understanding the challenges of hard rock ISR and identifying global capabilities that can contribute to developing the essential enabling technical areas required to realise ISR. Specific focus areas include geochemistry and advanced resource characterisation; drilling and controlled rock-breaking technologies; solution chemistry and environmentally benign lixiviant systems; lixiviant delivery systems and ‘subsurface mixing’; subsurface hydrology and reactive transport mechanisms and models; downstream processing options; legal, social and environmental aspects; and techno-economic modelling. This paper will discuss ISR challenges including industry feedback focused on addressing this issue, gaps preventing ISR from being applied in practice, capabilities to overcome these gaps and the development of a collaborative approach to making hard rock ISR a reality.CITATION:Kuhar, L L, Breuer, P, Robinson, D J and McFarlane, A, 2015. Making hard rock in situ recovery a reality, in Proceedings Third International Future Mining Conference, pp 189–196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By Totterdell JM

The Permian-Triassic Bowen Basin and the Jurassic-Cretaceous Surat Basin evolved in a backarc tectonic setting behind an active convergent plate margin in eastern Gondwana. Several extensional (Early Permian; Eocene) and contractional (mid- Permian; Early Triassic; Middle-Late Triassic; early Late Cretaceous) intraplate deformational events are recognised in the basins. These can be correlated with similar events in the New England Orogen that was being deformed in the Late Permian- Late Triassic as a foreland thrust belt. The intraplate deformations were probably the consequence of plate interactions, including the accretion of terranes, at the ancient active plate margin, remnants of which now occur in New Zealand.

Jan 1, 1995

It is indeed an honour to address the perth branch of the australian institute of mining and metallurgy and to have the opportunity to talk to you about the future role of upgraded ilmenite on t102 feedstock supply and demand. There have been many papers written on upgraded ilmenite supply and demand and now I would like to share with you QIT's view of the situation first, a word about demand, although I will be talking principally on the supply issue. The principal use of t102 is in the manufacture of pigments which, in turn, are used in paints, plastics, and the paper industry together with a few miscellaneous uses, while a further b% or so of t102 minerals are consumed for the manufacture of titanium metal and for the manufacture of welding electrodes. the total demand for contained t102 is of the order-of 3 million tons per annum, and the general consensus in the industry is that growth rates should be of the order of 2% annually- it is against this backdrop that suppliers must compete with one another and produce least cost materials for the pigment industry. At the moment, supplies are relatively tight, but the generally slow growth in demand coupled with the abundance of titanium bearing minerals should ensure that long term the reverse is generally true. Now, let us examine the supply situation. Titanium is the 9th most abundant element in the earth's crust, so the problem from the producers` point of view is not one of scarcity of titanium minerals, but of how to extract most economically t102 feedstocks from a wide variety of choices- up to the present, all titanium feedstocks are being derived from either rutile or ilmenite rutile, at about 95% t102 content, is indeed a premier raw material which does suffer from potential scarcity and rutile supplies will likely be a diminishing factor in future decades- whereas ilmenite, a combination of iron and titanium oxides found in varying ratios, may be found in huge quantities all over the world.

Jan 1, 1986

By Graham J

The successful processing of arsenopyritic ores is difficult and will be facilitated by a better understanding of the mineralogy of gold within arsenopyrite and the type of arsenopyrite in which gold is taken up. Solid solution gold in arsenopyrite is now well documented, and is a significant cause of refractory behaviour in gold processing. Investigations of the crystal structure and stoichiometry of arsenopyrite by X-ray diffraction, electron microprobe analysis and convergent beam electron microscopy have been carried out in order to understand how the gold is incorporated into the structure. Variations in stoichiometry, particularly the As:S ratio, of arsenopyrite leads to variations in structural parameters. These variations result in slight changes in thermal behaviour. The distribution of invisible gold in an arsenopyrite grain is generally non-uniform and synthesised samples contain up to 2 wt per cent gold. A transmission electron microscopy (TEM) technique called ALCHEMI is being used to identify the substitution site. The process of gold agglomeration together with evidence of an ordered breakdown of arsenopyrite to pyrrhotite has been documented with the use of TEM. An arsenopyrite grain containing invisible gold was heated with an electron beam resulting in recrystallisation of arsenopyrite to pyrrhotite with arsenic being expelled. The gold is mostly insoluble in the pyrrhotite lattice and therefore exsolves out and combines with other gold atoms to form droplets at the boundary of the pyrrhotite.

Jan 1, 1992

By Hanna P

Coal geologists are under pressure to minimise exploration expenditure, maximise interpretation confidence and produce the results often too soon. This pressure continues to increase as companies are forced to evaluate borderline economic deposits which are usually deeper and more hazardous, such as the Togara North and Togara South projects in Central Queensland.

Jan 1, 1998

Commercial explosives range from pure emulsions to pure ANFO, with blends of these providing interesting alternatives: energy is often adjusted through addition of aluminium, or the control of density. The energy rating of explosives is derived chiefly from detonation codes, which are used to derive expressions for the internal energy change of the detonation products as they do work under expansion. While all codes used for this purpose work on the basis of Ideal detonation, it is common knowledge that commercial explosives operate in the Non-Ideal domain, which affects the mode of energy delivery to the environment. However, since Ideality represents the foundation from which actual performance evolves, it is valuable to examine the intrinsic energy release of a formulation before attempting to understand the influence of Non-Ideality. In examining the Ideal pressure profile of fundamental formulations, remarkable correlation has been found with field performance, and this increases understanding of the influence of various formulation modifications, especially in regard to the stage at which energy is released, and the effect on rockbreaking. This work has emphasised the value of attempting to understand and define better the non-ideal detonation process.

Jan 1, 2001

The Geograph is a revolutionary seismic system involving special techniques in combining the use of FIT magnetic tape with shock wave echoes created by a weight dropping system.The idea of- weight dropping as a- source of seismic energy is not a new,.,oxie. Records 'indicate òa pos'sihle use of falling weights as early as .1929. 'Dr. Burton McCollum began his experiments in 1938, but it wasn't until 1951 that the method was first proven useful.The first weight dropping crew began commercial operations in Edwards and Sutton .Counties of West Texas in 1953. By 1962, more than '40 weight drop-ping.crews have come into existence with operations in the United States, Canada, Algeria, Iraq, Argent na,òSpanish West Africa, Tunisia, Qatar, Niger Morocco and Libya by most major oil companies and larger independent oil companies. .

Jan 1, 1962

This paper is a tribute to the late Dr Donald Martin Hausen as a father of applied mineralogy. His dedication to promoting the field through technical societies and through his professional work was outstanding, and his activities as a humanitarian are noteworthy. Dr HausenÆs involvement in technical societies included organising and conducting the only ICAM congress that was held in the USA, co-founding and nurturing the Process Mineralogy Committee within the American Institute of Mining, Metallurgy and Petroleum Engineers, and participating in CAM, the International Mineral Processing Congress, as well as other technical societies. The Process Mineralogy Committee that he co-founded has continuously organised annual meetings in the USA by conducting a series of sessions, and 17 books on the proceedings from those sessions have been published. As an applied mineralogist Dr Hausen solved many problems in exploitation and processing of minerals, metals and materials, especially gold. He helped to find many Carlin-type gold orebodies by outlining targets using alteration halos as determined by X-ray diffractometry, and he defined mineral characteristics that affected gold metallurgy and cyanidation. It is also noteworthy that Dr Hausen and his wife, Mary, opened their arms and home to many foster children and were instrumental in their placement in many homes. They also sponsored refugees from south-east Asia, taught them English, housed them, and provided constant support until the refugees became responsible and independent US citizens.

Jan 1, 2008

By Mould GR

Gas drainage has been practiced for many years mainly for safety reasons in various countries in Europe, in the U.S.A., the U.K. and Japan. Legislation has been developed to control the production, transport- ation and utilisation of methane and associated gases. Gas drainage is now being carried out at some Australian Collieries, but as this is a new venture little specific legislation is available. This paper briefly describes the drainage methods and legislation applied overseas, gives a brief history of gas drainage in N.S.W. and indicates the deficiencies of the present legislation. It outlines the approach to new legislation which will deal comprehensively with gas drainage operations and utilisation in New South Wales.

Jan 1, 1982