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By Ruxton B. P, Rhodes J. M

Two Rb-Sr ages are discernible in data concerning the leucocratic granite which is the youngest pre-sedimentation phase of the crystalline basement complex at Rum Jungle, Northern Territory, Australia. Whole-rockdata suggest that intrusion of this unit took place at about 2400 my ago, with a probable initial ratio around o·707; whole rock-potassium feldspar tie-lines indicate redistribution of strontium at about 1800 my ago. The former age correlates with other measurements on rocks which form basement to the mantling Pine Creek Geosyncline; the latter correlates also with isotopic evidence for regional metamorphism and emplacement of some younger intrusive granites elsewhere within the geosyncline. A few K-Ar ages, from scattered localities, conform generally with the later event or events which appear to have some connection with the structural deformation clearly observable both in the complex and the surrounding metasediments. It is these younger events which appear to match the residual evidence for the earliest detectable concentration of uranium minerals in the Alligator Rivers district.

Jan 1, 1977

By Cordner G. D

Titanium is not yet being produced on a commercial scale despite the facts that it has some impressive properties, and that it occurs very abundantly in easily-mined, highgrade oxide ores. One important reason for this is that the excellent mechanical properties of the metal were not widely recognised and appreciated until about twenty years ago.Another factor which has tended to retard progress in titanium metallurgy has been the realization that the oxide minerals of titanium are very stable; in other words, considerable energy has to be expended to reduce the oxide to metal. Table 1 presents the minimum energies which would have to be expended to produce one ton of each of the metals, aluminium, magnesium, titanium and iron from their respective oxides under theoretically ideal conditions at normal temperature and pressure. At higher temperatures, the minimum energy requirements are different, but the values for the various metals still fall in the same order as indicated in Table 1.In actual fact, the energy consumption in the case of any particular metal is higher than the ideal value by an amount which can be determined only by' the results of plant practice. The only general conclusion that can be drawn from the data in Table 1 is that it might eventually prove...

Jan 1, 1950

Interest in industrial minerals in recent years has increased to such an extent that it has taken them into the mainstream of the Australian mineral industry. Notwithstanding that time series data on the values of production, exports, and imports show that industrial minerals are overshadowed by metals and energy minerals, their contribution to the national economy is important and more significant than would seem to be indicated by the statistics. Whereas the ex mine value of metals generally includes some processing (at least to a concentrate stage), most industrial minerals are valued at little more than their extraction cost, in addition to which such costs are generally low because most industrial minerals are exploited in low-cost surface operations. Consequently, values of mine production of metals and industrial minerals are not strictly comparable in that values of mine production of metals tend to be overstated Short term growth of the industrial minerals sector is assured because of several new projects already commissioned but not yet reflected in the statistics. Longer term growth is also assured, based on various other major projects that are likely to come on stream in the early to mid 1990s.

Jan 1, 1989

It is easy to demonstrate the importance of aggregates in any conversation about infrastructure and other engineering artefacts. Peoples around the world have made use of stone to enrich and enhance their lives since the earliest days of civilisation. In New Zealand, Maori used hard durable rocks for weapons, tools, and basic structures. European settlement accelerated the use of quarried materials and formed the basis for development of our society as we see it today. Logic might suggest that the quarrying sector would be recognised positively for, and encouraged to continue to contribute to, this underpinning of the way we are. The reality is æNot In Most Back YardsÆ. Why? The rock is where it's always been (often overlooked) and our æsocialÆ environment is today's hard place. For a resource-based business in New Zealand, that environment is principally the Resource Management Act, with the widespread power it has distributed to anyone prepared to invest their time. This coupled with a lack of leadership and direction in the implementation of the Act has created a climate that stifles development and diverts energy and resources to æplaying the gameÆ rather than ælifting the gameÆ. Perhaps the real costs of this are not yet widely recognised. The paper will draw mainly on the experience of endeavouring to consent a ægreenfieldÆ quarry in the Waikato region. This is supported by commentary based on nearly 10 years of ælivingÆ with the RMA at sites across much of New Zealand. RMA Scorecard Summary: Effects based? Rarely. Level playing field? No. Maori Consultation? Could do better. Efficient use of resources? No. Timely? No. Is it working for other sectors? Certainly not the quarrying industry's customers and end users.

Jan 1, 2000

Base metal sulphide mineralisation on the northern end of Great Barrier Island is spatially associated with hypabyssal intermediate to acidic intrusives, in transgressive structures in indurated, complexly deformed greywackes and argillites. Copper predominates in the mineralisation, with minor accompanying lead and zinc and also some gold and silver. However, in some cases lead or zinc may be the dominant constituent. The mineralisation is generally characterised by only narrow envelopes of weak alteration (propyliticassemblages dominated by chlorite and epidote) and with only minor amounts of quartz accompanying the sulphides, which form a cement in zones of hydraulic fracturing. There are two distinct structural settings to the mineralisation: at MinerÆs Head, in a structurally complex situation in a shell-like zone of crackling in hornfelsed greywacke, in association with both north- and east-striking fractures and rubble breccias associated with the apical part of a large intrusive; and in very narrow, but very strike-persistent, 1inear steeply-dipping fracture zones, exposed on the north coast and inland areas near Tataweka.

Jan 1, 1984

By J Loimi, P Minkkinen, T Korpela

The head loss caused by metallurgical sampling for slurry streams can be reduced by metallurgical sampler design. When the process volumetric flow rate is reduced by vertical static cutters before the sampling by an equal number of moving cutters to the static cutters, the installation requires less installation head space than other sampling arrangements and is easy to accommodate at suitable locations in the process. Low head loss reduces building costs for the processing plant and operational costs during the lifetime of the plant.The presence of a possible systematic bias in the particle size distribution, solids density and elemental composition between an Outotec MSA 2/50 metallurgical slurry sampler sample and MSA 2/50 manually sampled reject have been studied by a customer. The paired samples were taken as simultaneously as possible. The customer evaluated the possible bias using a paired t-test and provided the assay results to Outotec for further evaluation.The results of the paired t-test showed no systematic bias in particle size distribution, solid density or assayed analytes, except in one analyte with low content and a high relative error. The high relative error in one analyte may have been caused by the same calibration model used in a X-ray fluorescence analyser for both high elemental-content concentrate and very low elemental-content tailings samples. The sampled stream is the tailings of a previous process stage.The results of the t-test were studied further using analysis of variance to reveal the error sources in samples. The results showed no bias between the samples collected from the MSA 2/50 reject and composite samples collected of the MSA 2/50 sample stream. The courier online analyser data was also available for evaluation of representativeness to the process stream.The analysis results of the courier online analysis reveals no bias between the MSA 2/50 reject samples, MSA 2/50 sample stream composite samples and online analysis results during the comparative sample collection period.CITATION:Loimi, J, Minkkinen, P and Korpela, T, 2017. Comparative evaluation of manual sampling and Outotec MSA 2/50 metallurgical slurry sampler, in Proceedings Eighth World Conference on Sampling and Blending , pp 167–172 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

Thirty mixed cultures of microorganisms from soil, water and mineral samples from the Groote Eylandt Mining Company mine site were approximately three times more effective in biodegrading manganese dioxide (34± 18 mg Mn++/1/day) than sixteen purified strains (11 ± 10 mg Mn++/1/day) isolated from the primary enrichment cultures. Two pure bacterial genera identified as a Pseudomonad and a Bacillus, with an excess MnOz and nutrient, were able to dissolve 106 mg Mn++/litre/day in mixed culture compared with 29 mg Mn++/litre/day when grown separately.

Jan 1, 1983

Rheological Behaviour of Clay-Rich Gangue Mineral Dispersions During Hydrometallurgical Treatment Alumino-silicate minerals invariable may present an intractable challenge in hydrometallurgical operations employed in low grade nickel, copper and gold ore leaching or high level nuclear waste (HLNW) processing. The interactions and reactivity of alumino-silicate clay gangue minerals such as muscovite/sericite, chlorite, kaolinite and smectite under acidic (eg pH <3) or alkaline (pH >13) conditions can have a striking impact on the particle interactions. These may manifest in undesirable pulp rheology, poor extraction rates and challenges in the subsequent "handleability" and solid-liquid separation processes (eg dewatering). In the present work, a review of investigations involving the interfacial chemistry, interactions and rheological behaviour of aqueous dispersions of mica-group, layered alumino-silicate clay (muscovite / sericite) and chalcocite minerals as a function of pH in the range 2 - 9 and time at 25¦C, is presented. Particle zeta potential, reflecting interfacial chemistry, indicated a strong pH-history and particle volume fraction dependency. Pristine particles' zeta potentials measured from high to low pH indicated mineral-specific isoelectric point (iep) at pH range 2 - 5. Subsequent measurements from low to high pH showed pH-history dependency with iep shift to higher pH values, the extent of which also depended upon particle volume fraction and aging time. Pulp pH-mediated particle interactions revealed by shear yield stress analysis displayed a bifurcation behaviour and good compliance with DLVO theory. The maximum pulp yield values occurred at the iep whilst weak rheology was observed where the magnitude of the particle zeta potential was greatest. The pivotal role played by both pulp chemistry and suspension conditions in regulating the particle interactions and concomitant rheological behaviour is highlighted. The implications of the findings with regards to clay-base pulps' handleability and its control during aqueous processing are discussed.  

Sep 13, 2010

By Warren L. J

The effectiveness of shear-flocculation as a method for upgrading simple mixtures of ultrafine (1-11 \lm) scheelite and garnet was evaluated. Statistical methods were used in the design and analysis of the main test program.The stirrer speed, stirring time, and initial weight ratio were all found to have significant effects on both the recovery and grade of the floes produced. The particle sizes also had an effect on the final grade. There were several important interactions between factors which also affected the results. Optimum conditions for shear-flocculation were established, and under these conditions about 80 per cent of the scheelite could be recovered at a grade which depended on the composition of the starting mixture. Starting with mixtures containing 10 and 50 per cent scheelite, the best final grades were between 20 and 50 per cent and between 70 and 90 per cent respectively, the actual value depending on the particular combination of particle sizes.

Jan 1, 1977

Fine coal is defined as material with a maximum size of 1/2 in. Various methods for separate washing of such coal are discussed briefly because separate treatment can lead to a higher overall recovery of coal or to a product having a lower ash content.A felspar jig is discussed in detail because it is the method most recently adopted in Australia, and because it has the advantages of compactness, flexibility and automatic Gontrol, with minimum operator attention. This jig has a variety of adjustable controls to enable the desired results to be obtained from a wide range of coals and the general application of each control is discussed.The only separate treatment of fine coal in the Illawarra district is by felspar jigs on Bulli seam coal.INTRODUCTIONAll reasonably large Australian collieries now win coal by mechanical methods. but while mechanization leads to more economic production of high tonnages, it also changes the characteristics of the coal won. In particular there is an increased proportion of fines, and an increased ash and moisture content. However, specifications of coal for sale have become more stringent, and consumers now require coals in a definite size range with a lower and more uniform ash content, as well as with a low and uniform moisturecontent.These factors have led to the need to wash and grade run-of-mine coal at the pithead. In' plants where the whole of the run-of-mine coal is treated in a jig, some of the fine coal in the feed is beneficiated; the extent depending on factors such as the type of coal and the feed rate. However, for dense medium treatment, fine coal must first be screened out, and there may then be no washing of fine coal at all.

Jan 1, 1961

The seams of black coal occurring in Victoria are so disturbed by faulting, wash-outs, thinning, etc., that it is necessary, for the prevention of costly errors in development, that close boring be undertaken so that the correct positions of the shafts, tunnels, main and auxiliary roadways can be set out in order that the area can be economically worked. The State Coal Mine has two boring plants continuously at work, which have given good service for the last twenty-five years.The information supplied herein is merely our experience in boring at the State Coal Mine over an extended period. The type of plant in use is that known as the Victoria Drilling Plant, equipped with an 11 h.p. portable oil engine, using power kerosene as fuel. It was purchased in 1914, complete with mechanism for cable drilling, capable of boring to a depth of 1500 ft. with a guarantee of 1000 ft., with Calyx cutters, boring rods and all necessary equipment for the sum of £1473. The chief mechanical features of the plant are as follows:-The derrick is in the shape of a tripod (see Fig. 1), two of the legs being of steel channel built together to form a frame which, when lowered on to two sets of road wheels, forms a carriage for the transport of a portion of the boring equipment. The third leg is made of oregon in the form of a double bow, with bolts and distance pieces between the wooden sides. The top of this is hinged on to the steel frame, and the bottom is fitted into a cast iron block, having two small wheels to facilitate erection. A rope attached to the cast iron block and to the winch easily...

Jan 1, 1936

Geophysical methods are useful non-invasive means of collecting subsurface information on the environmental impacts of resource developments. Techniques such as seismic refraction, ground probing radar and magnetics are well established tools for environmental studies of waste disposal sites. Repeat resistivity surveys, gravity surveys, and infrared or multispectral remote sensing hold great promise for monitoring environmental changes. Examples from New Zealand include geothermal field monitoring, which may involve the use of geophysics for .detecting changes of surface thermal activity, hydrothermal eruptions, induced earthquakes, contamination or depletion of shallow groundwater, and subsurface fluid recharge. Other examples include resistivity monitoring of contained effluent disposal ponds, tailings dams and landfills. Experience has shown that care is necessary to identify the natural variability of the parameter measured before drawing conclusions regarding an observed change.

Jan 1, 1994

Various steps, and complete sequences, for the recovery of lead and zinc from a mixed sulphide concentrate, high in silica and pyrite, have been tested.Oxidation steps of roasting in air or in a sulphating atmosphere and use of aqueous acidic, ammoniacal, and near neutral oxidation media were compared. Oxidation roasting or use of acidic media appeared most useful. Procedures for dissolution of zinc from calcines using sulphuric and sulphurous acid to avoid silica gelation problems are compared and a direct leaching procedure with sulphuric 'acid at controlled pH shown to be the most useful.Methods for the removal of germanium, nickel, and magnesium from zinc sulphate solutions prior to zinc electrodeposition were tested. The recoveries of zinc from ammoniacal solutions by electrolysis and distillation are compared.The dissolution of lead compounds from the residue of zinc extraction by amine and ammoniacal ammonium sulphate (AAS) solutions Was tested. Lead, sulphide was precipitated in filtera'ble form from AAS solutions. The reduction of lead sulphate to lead sulphide with sulphur was difficult, but possible. The various steps were used to deveiop five complete processing sequences, of which two were shown to be technically feasible and have potential economic viability.

Jan 1, 1975

By M A. Lund, C D. McCullough

In Australia and worldwide, open cut mining has become increasingly common over the last few decades through changes in excavation technology and ore economics. However, such operations frequently leave a legacy of open mine pits once mining ceases. Pit lakes will then form in mine pits that extend below the water table when dewatering operations cease. Pit lake waters are typically contaminated with metals, metalloids, saline or acidic/alkaline and rarely approach natural water body chemistry. Physically, pit lakes have unique bathymetries, are often strongly wind sheltered and have very small catchments. Nevertheless, pit lake waters often constitute a vast resource but of limited beneficial use (due to water quality issues); with a potential to contaminate regional surface and ground water resources. Water in pit lakes has the potential to be useful for a range of purposes in the Australian context of characteristic hot, dry climate and relatively few natural water bodies. Consequently, pit lakes can be seen to represent either a significant liability or a water resource to mining companies and regional communities. However, the lack of knowledge on pit lakes continues to hinder their proper management. This paper summarises the limited information currently available on water quality associated with Australian pit lakes. Information on pit lake occurrence, distribution and water quantity and quality is not nationally collated and requires immediate and ongoing attention from both mining companies and regulating authorities. Lack of a readily available database for pit lake occurrence, distribution and water quality fails to realise the potential for these water resources by both mining companies and Australian communities. Lack of access to pit lake quantity and water quality data may also lead to failure to manage this significant source of mining environmental risk.

Jan 1, 2009

Computer applications are ideally suited to the day to day operations of grade control and short term planning on a mine site. By refining this part of the operation there is scope to increase profits by more accurately predicting ore grade and tonnage, and allowing the mining engineer more flexibility in his approach to scheduling. Large numbers of blasthole or ditchwitch samples need to be processed in a fast and efficient manner, and stored in a database for future reference. The mining engineer has to calculate tonnages and subdivide the blast or digging area into mineable areas of waste, low and high grade ore. New grade and tonnage information must be used by the mining engineer to update his short term plan. Answers must be obtained quickly and efficiently, but a high level of individual input is necessary in order that maximum use is made of the information. Geostatistical analysis of samples can be used to refine the interpolation techniques. Reconciliation between the original grade model, the newly sampled area, and the final product should be monitored continually.

Jan 1, 1989

Retreating Cu-Mo Rougher Tailing by Flotation for Concentration of Copper and Molybdenum

Sep 13, 2010

By Worner H. K

Education has always been a topic to rouse the interest of mining and metallurgical engineers, but the recent activities of the Education Committee of the Australasian Institute of Mining and Metallurgy 1, 2, together with the moves throughout the Commonwealth to extend the field of technological education, have made the subject a very live one at the present time. The authors have felt it would be appropriate that on the occasion of the First Ordinary Meeting for 1950, in Victoria, some contribution should be forthcoming concerning the history, present status and possible future trends of mining and metallurgical education in this State. As for the past, the time approaches when there will be none having personal recollections of the beginning of Victorian mining schools or of the men who started them. As for the future, it is obvious that rapidly expanding metal-producing and metalconsuming industries will demand a greater output of competent graduates and diplomates. The era immediately ahead seems to be bristling with opportunities, but mining educators need to temper their enthusiasm for various policies and programmes with the realisation that they are helping to train men who will be leaders 15-20 years hence when the problems of industry and trials of life generally may be very different from what they are to-day.

Jan 1, 1950

By Clarke DS

The igneous intrusions in SE Papua New Guinea are part of a sub-volcanic to plutonic, high-K calc-alkaline to shoshonitic suite. High-K andesitic to dacitic intrusives on Misima and Woodlark Islands, and shoshonitic intrusives in Milne Bay and the eastern Owen Stanley Ranges are related to late Cenozoic andesitic volcanism. Both suites are associated with epithermal Au-Ag deposits and weak porphyry Cu-Au mineralisation. All significant alluvial and lode gold occurrences in the region are spatially related to intrusions. Intrusions in the D'Entrecasteaux Islands and near Mt Suckling are core plutons related to basement doming, and appear to have no association with either volcanism or hydrothermal mineralisation. The core plutons are not petrochemi:ally distinct from the volcano-re:-ed Intrusions.

Jan 1, 1991

By S L. Garwin

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Since the Eocene, New Guinea tectonics have been driven largely by the south-westerly-directed collision of accreted arc terranes with the northern margin of the Australian Craton, and subsequent westerly-directed transport of these exotic terranes by left-lateral strike-slip fault systems. The subduction of the Solomon Sea plate beneath north-eastern New Guinea in the mid- to late-Miocene led to magmatism and related gold-copper porphyry and epithermal mineralisation in the Maramuni arc and the formation of the Frieda River, Nena, Wafi-Golpu and other deposits.The development of the world-class porphyry and epithermal deposits in the Medial New Guinea magmatic belt, including Grasberg, Ok Tedi and Porgera, is localised by dilational zones formed about the intersections of north-easterly-trending, reactivated basement faults and north-dipping reverse faults related to the southward progression of the Papuan fold belt during the Late Miocene to Pleistocene. These deposits probably formed during short mantle-derived magmatic episodes in zones of regional isostatic uplift, which are attributed to the delamination of the lithospheric mantle beneath New Guinea.CITATION:Garwin, S L, 2015. The tectonics, geology and gold-copper metallogeny of New Guinea, in Proceedings PACRIM 2015 Congress, pp 151–164 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By G de Jong, W Sunyoto, K Sari, P Silalahi

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Big Gossan mine is operated by PT Freeport Indonesia and is one of the largest stope-and-fill mining systems in the world. The Big Gossan deposit is a ~200 m wide, 1200 m long and 500 m high steeply north-east-dipping to subvertical skarn body at the Cretaceous-Tertiary Ekmai-Waripi contact. The copper-gold mineralisation, with a 1.3 per cent copper equivalent cut-off grade, occurs mainly proximal to the Ekmai-Waripi contact in the garnet-clinopyroxene prograde skarn at the base of the Tertiary Waripi formation and partly distal to the contact in the tremolite-actinolite retrograde skarn of the Tertiary Waripi formation.The Big Gossan stope mine is designed from 2540 m to 3020 m above sea level. Present active stoping operations occur at level 2540 mL to level 2640 mL and are done in a primary and secondary stoping sequence. The width and length of the stopes is 15 m and 20 m respectively, while the height of the stope varies between 20 m and 40 m, depending on the ground conditions. The stability of the stopes is visualised in the Mathew’s Stope Stability graphs. These graphs and actual Cavity Measurement Scanner measurements on the stope will predict and show the overbreak and underbreak, which affect the reconciliation of the mined stope and also the pillar stability between the primary stopes. Geological factors like major structures, joints, veins and alteration intensity are important factors that correlated with the stability of the Big Gossan stopes.CITATION:Sari, K, de Jong, G, Silalahi, P and Sunyoto, W, 2015. Stope stability at the Big Gossan skarn deposit, Papua, Indonesia, in Proceedings PACRIM 2015 Congress, pp 139–146 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015