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A short account is given of the theory and practice of determining the true U3O8 content of ore samples by the determination of the beta and gamma activities separately, using the method of Eichholz and his associates.It is shown that, despite the variation of sample activity without change in U3O8 content, the true U3O8 value can still be found.Thorium can be determined simultaneously if this element is also present.

Jan 1, 1957

With some notable exceptions, marine placers located just below, or just above, present sea level, are responsible for much of today's production of detrital ilmenite, rutile, zircon, and other minerals of value. The purpose of this paper is to discuss the paleogeographic and paleo-oceanographic factors which may have determined the location of presently submerged marine placers. These factors include changes in sea level, burial by recent marine sediments, stream capture and other changes in drainage patterns, and recent changes in climate. Selected geologic situations in the Yellow Sea off the coast of Korea, in the Atlantic Ocean off the coast of Portugal, in the Bering Sea off the coast of Alaska, and in the Arabian Sea off the coast of India, will be used to illustrate the author's point of view.

Jan 1, 1971

Despite a long history of production of industrial minerals and rocks, New South Wales still offers significant opportunities for exploration for and development of these minerals. Exploration for opal, sapphires, and zeolites in the State has been particularly encouraged by pioneering geological studies by the Department of Minerals and Energy, which have resulted in the development of important new geological concepts and exploration techniques. Large areas with potential for these minerals have not yet been tested. In the case of sapphires, the studies have identified a new type of deposit which is'the source of most of the sapphires mined from alluvial deposits. Recent price increases for heavy minerals, a re-evaluation of previous exploration in coastal regions, and a recognition of suitable environments in inland New South Wales have stimulated renewed exploration both onshore and offshore and have led to increased production. Significant potential also exists for development of a number of other minerals, including: topaz, which occurs in large, unusual and perhaps unique deposits in northern New South Wales; dimension stone (particularly granite); bentonite; diatomite; and silica for metallurgical use. Potential also exists for development of construction material resources, particularly construction sand, which is in short supply in the Sydney region.

Jan 1, 1989

By T J. Sprott, Associates

A number of people have expressed concern, understandably, that if mining operations take place in the Coromandel, the flows of mineralised ground water which exist will be intercepted. This water in many cases contains toxic metals including mercury, arsenic and lead and it is thought that if this water is allowed to enter streams or the waters of the Hauraki Gulf, it could endanger natural marine life and possibly established fisheries. This paper seeks to explain in simple terms the geology and the process of deposition of the various mineral deposits in the ground, the chemistry of the reactions between these minerals and the rain water falling on the ground, the hydrology and behaviour of this mineralised groundwater as it moves through the ground until it eventually enters the sea.

Jan 1, 1981

Study of Bauxite Separation by Using Flotation Column

Sep 13, 2010

Effects of DA as a Grinding Aid on Selective Grinding of Low-Grade Bauxite Effects of DA (a copolymer of acrylic acid and acrylamide) as a grinding aid on selective grinding of low-grade bauxite were investigated in this study. The addition of DA into the grinding system enhanced the selectivity of grinding and increased the A/S ratio in the coarse fraction of ground product, leading to improved throughput of grinding mills and alumina recovery. The results showed that DA decreased the viscosity of slurry significantly and hence improved grinding efficiency due to low viscosity at a high slurry concentration. Both the hydrogen bond formation and chemical adsorption existed between DA and the surface of bauxite particles. The adsorption of DA on the surface of bauxite could decrease stress needed for crack initiation and extending during grinding, prevent new-born crack surfaces from rejoining, and promote the expansion of the cracks.

Sep 13, 2010

The final criterion of the payability of gold production must necessarily be the cost per ounce. While the cost per ton or per cubic yard is a convenient comparative measure, and a necessary one for operating control, it is obviously insufficient as a means of judging whether or not, in a given set of circumstances, a gold production operation can be carried out economically.. An alternative method, which brings in the ton or cubic yard as a unit of measurement, is to determine what the cost per ton or per cubic yard is equivalent to, in terms of pennyweights or grains at the ruling price of gold. But this is really only another way of stating that the cost per unit of product is the ultimate measure of profit or loss, and not the cost per unit of input material.It is accordingly of interest to determine the cost per ounce of Australian gold production and to compare it with the cost of gold production in some other parts of the world which are important gold producers. The attached Appendix, which it, is believed comprises practically all Australian mines of any consequence (except Big Bell and the de Bernales group, for which. insufficient information is available), shows this information for financial years ending between 31st December, 1938, and 31st December, 1939, the production of gold dealt with being some 1,084,000 oz., or 66% of the total Australian production for 1939. For comparative purposes the cost of producing gold at representative mines in New Guinea, New Zealand, Fiji, Canada, India, West Africa and Rhodesia, and the average cost of production at the Rand mines, has also been included.It is obviously necessary in a study of this sort that the basis of the cost should be clearly set out and should be as nearly as possible uniform. The "cost" as calculated herein comprises the following items:

Jan 1, 1940

By K Ehrig

You are a geologist, geometallurgist, or metallurgist/process engineer and are fortunate enough to work for an organisation who asks you to design/execute a geometallurgy program. What seems like a simple request is actually not a trivial exercise. æRecipeÆ style manuals are not readily available. However, many æexpertsÆ are lurking around willing to deliver solutions which will solve all of your problems. Even though similar ore deposit styles (e.g. porphyry Cu, IOCG, Ni-laterites, calcrete hosted U, etc.) have many similar characteristics, each ore deposit is unique. Hence your geometallurgy program needs to be æfit-for-purposeÆ. This paper offers some insights gained via designing and executing geometallurgy programs from exploration through to production, and working at a mine where you are held accountable for your metallurgical performance predictors.CITATION:Ehrig, K, 2013. Geometallurgy - What do you really need to know from exploration through to production?, in Proceedings MetPlant 2013 , pp 28-33 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

Real Time and In Situ Measurement of Elemental Composition Using Lasers

Sep 13, 2010

By E Apaza, R Neumayr

This paper aims to summarise the discovery of the QTS Central resource, a previously unidentified +1 Mt inferred resource that lies between two major CSA resource systems.The 1.7 Mt at 5.76 per cent Cu, QTS Central ore system represents 1/6th of the CSA mineral resource and was discovered in 2014 based on the accumulation of historic exploration records dating back to 1989.The CSA deposit consists of five ore systems hosted within turbidite-derived siltstones (CSA Siltstone) and lesser sandstones (five per cent) of the Devonian Amphitheatre Group. The host sediments strike approximately north–south with a steep westerly dip and exhibit a well-developed east dipping cleavage. Most CSA mineralisation is hosted within dilation zones at the intersection of cross-cutting structures and is interpreted as epigenetic in origin.Alteration and weak mineralisation, up plunge to the reported QTS Central mineral resource, was initially detected in 1990 during a downhole electromagnetic conductivity (EM) study, where one hole indicated an off-hole conductor, later tested with four diamond holes. One of these diamond holes intersected 3 m at 7.5 per cent Cu at 200 m. Development of the 9070 Subway drive in 2005/2006, linked the QTS North and QTS South workings and intersected structures interpreted to host QTS Central mineralisation. Subsequent drilling proximal to the 9070 Subway in 2007 identified an up plunge extension to the QTS Central zone (UDD07152: 1.8 m at 6.3 per cent Cu from 10.7 m). Work on QTS Central was largely forgotten until 2012 when the mining of a 450 m infrastructure drive provided a platform to test the anomalous grades. In December 2013, drill hole UDD13055A intersected 20.9 m at 7.2 per cent Cu from 378 m. By the end of 2014, the QTS Central inferred resource was 1.0 Mt at 6 per cent Cu and 18 g/t Ag (Hosken and Apaza, 2014). Late in 2016, further infill drilling occurred from two fronts to increase confidence in the QTS Central resource. The results of this drilling are expected late in 2017.The current interpretation indicates the QTS Central system consists of two main lenses hosted within closely bedded sandstones and siltstones. The sandstone in general is not mineralised, being heavily silicified, while the siltstone is mineralised and chloritised. The main mineralised lens is 75–200 m along strike and 450 m high. Massive sulfide feeder structures lie at the core of the two main lenses, although the characteristics of the QTS Central system tend toward the mineralisation being more chlorite-rich than in QTS North and QTS South.CITATION:Apaza, E and Neumayr, R, 2017. The discovery of the QTS Central ore system, CSA mine, Cobar, NSW, Australia, in Proceedings Tenth International Mining Geology Conference 2017, pp 151–156 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

Process Simulation and Plant Design of a Mineral Selective Magnetising Flash Roasting Plant Using Neutrons

Sep 13, 2010

Chelopech Mining EAD and Best Available Techniques for Management of Waste Rock in Mining Activities

Sep 13, 2010

By R Lewis

Drill hole magnetometric resistivity (DHMMR) is a relatively recent addition to the explorationistsÆ suite of techniques for finding further resources in the vicinity of a drill hole. The method relies on gathering of an applied current into zones which are less resistive than the country rocks and it was first applied to exploration programs looking for weakly conductive sulphides, such as, for example, carbonate-hosted zinc deposits. More recently, it has been applied to a wider range of deposit styles, including highly conductive nickel sulphides. It has been found that the technique is capable of not only detecting mineralisation not seen by conventional electromagnetic (EM) techniques, but it can detect at a greater distance. Also, whilst EM is superior at defining tabular-shaped conductors, DHMMR may be more effective at finding cigar shaped sulphides. This paper presents a number of examples illustrating these findings.

Jan 1, 2000

By G J. Corbett, P Magner, M McKenzie

Structures formed during ductile deformation have been reactivated during the later brittle mineralisation process. Two generations of folding are classified as: early recumbent megascopic FI folds and FI shears which transpose the hinge regions, and later upright F2 folds. S1 is folded about F2 folds which contain axial planar S2 crenulation cleavage. Vergence relationships between S1 and bedding indicate that many of the mineralised structures occupy sites of FI folds which have acted as plumbing systems for later gold mineralisation (eg Blackwater mine). The Globe-Progress gold mineralisation is localised by a major jog formed by sinistral strike-slip movement on two FI fault segments and mineralisation also occurs in smaller jogs along strike (eg Sir Francis Drake, Happy Valley-Merrijigs, Cumberland).   The lodes of ribbon quartz which exploit the FI shears and local bedding planes, are inferred to have mostly formed after the peak of metamorphism, possibly related to the emplacement of Carboniferous granites. This was followed by a sequence of vein deposition and wallrock alteration which consists of quartz-As/Fe sulphides ? carbonate - stibnite ¦ trace base metal sulphides and Bi-sulphosalts ? illitic clay/sericite-chlorite. Gold at Globe-Progress is mainly encapsulated in arsenopyrite. At Blackwater, free high fineness gold occurs in partings in lode quartz with late sericite-chlorite. The above sequence of events is comparable to that encountered in many intrusion-related gold systems throughout the Southwest Pacific region. There is a spatial relationship between gold mineralisation and dykes variably described as diabase, dolerite or lamprophyre. Alkaline rocks occur in many Pacific rim and older goldfields and may possibly be related to a magmatic source for gold mineralisation.

Jan 1, 1997

By H Sofatzis, J Kinal, J Siliezar, B Kirkwood

Ernest Henry Mining (EHM) is a copper, gold and magnetite mining and processing operation located 38 kilometres north east of Cloncurry in the Mount Isa - Cloncurry mineral district of north west Queensland, Australia. The EHM ore body is an iron oxide copper gold deposit with an average grade of 1.1 percent copper, 0.5 g/tonne gold and 22 percent magnetite.At the end of 2009, after a series of promising laboratory test work, EHM converted the ball mill media charge from forged steel to high chrome media. Laboratory test work also indicated that with the use of high chrome media, the pH was able to be reduced with no negative impact on plant performance. At high pH values (above 10.5), the forged media is passivated, so as the pH of the system drops the media corrosion rate increases and floods the system with corrosion products, affecting flotation. As the high chrome media is much more inert, pH has less of an effect on copper flotation response.This paper provides an overview of the effects of reducing the pH in the EHM copper rougher flotation circuit. The pH in the roughers was dropped from 10.6 to 9.6 to determine the impact on the rougher performance and the subsequent performance of the whole copper flotation circuit. It was found that there was a slightly increased improvement in copper recovery and no statistical change in either the rougher or final copper concentrate grades for copper and gold.With the reduction in pH, there was a noticeable reduction in lime usage from 0.85 kg of lime per tonne of ore processed to 0.55 kg/t. This reduction in lime is equivalent to approximately $700,000 per annum at current production rates.CITATION:Kirkwood, B, Kinal, J, Siliezar, J and Sofatzis, H, 2013. Low pH trial in the Ernest Henry Mining copper rougher flotation circuit, in Proceedings MetPlant 2013 , pp 371-377 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

Platiniferous horizons such as the Merensky Reef that are mined chiefly for their PGE contents constitute one end member of a continuum of Ni-Cu-PGE sulfide deposits; Ni-(Cu) sulfide deposits in which the PGE may or may not be by-products represent the other end of this continuum. Although it has long been thought that PGE-rich sulfides can only be developed by magma mixing in large magma chambers, new PGE data for the Bushveld Complex suggests an alternate model to account for origin of mineralization in the worldÆs most important Pt producer. Briefly, this model suggests that PGE-rich sulfides were initially deposited at depth below the Bushveld Complex as a result of interaction of a S-undersaturated mantle magma with S-rich crustal rocks. These PGE-rich sulfides were subsequently re-dissolved by a second magma, which introduced the PGE into the Bushveld Complex magma chamber, where the PGE-rich reefs were formed due to cooling of these magmas. If this model is correct, it means that large layered mafic/ultramafic intrusions are not a prerequisite for the formation of economic PGE-rich deposits. Exploration for Merensky Reef-type PGE deposits can be greatly facilitated by documenting variations in the background PGE contents of non-mineralized rocks collected on traverses across mafic/ultramafic intrusions; the mineralized horizons occur at cross-overs in ratios such as Pd/Cu, Pd/Se and Pd/S.

Jan 1, 2002

By H J. Stedman

A Transient Electromagnetic (TEM) geophysical survey was trialled in Bowen Basin Permian coal measures overprinted by Cretaceous intrusion. The trial’s intention was to compare whether TEM could assess residual coal more accurately and economically than drilling.TEM results were promising but had limitations. TEM did not compare to drilling for defining coal thickness or relative level definition. However, TEM resolved conductive anomalies laterally; providing a qualitative picture of remnant coal.Three material types and associated conductivities occur within the trial area: overburden (sandstone/siltstone), intrusive sills and heat affected coal.Ground conductivity was analysed by measuring decay of residual current within the TEM loop. Fast decay related to resistive overburden and intrusion, attenuated decay related to conductive coal.Generally speaking, carbon content governs coal resistivity where good quality, low ash, bright coal is more resistive relative to dull, high ash coal. Though in the trial area, relative to intrusion and overburden, coal was found to be the most conductive of the three materials.By modelling conductive anomalies, a general picture emerged of remnant coal regions. Subsequent highwall exposure reconciled with conductive TEM anomalies.CITATION:Stedman, H J, 2017. Findings from a transient electromagnetic trial for heat-affected coal, in Proceedings Tenth International Mining Geology Conference 2017, pp 233–238 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 20, 2017

In a previous paper the author showed that silver considerably delayed the recrystallisation of lead after cold work. The effect of antimony on the rate of recrystallisation of distorted lead was studied next, and the experiments performed, and the results obtained, are described in this paper. Electrolytic lead was used as a standard of comparison.It was also used to make the lead antimony alloys.This electrolytic lead contained 0.0005% total impurities.It was prepared from commercial lead by fire refining, followed by electrolysis and finally by vacuum casting. The process was described in the previous paper and the description need not be repeated here. PREPARATION OF LEAD - ANTIMONY ALLOYS.The steps taken to procure pure antimony are outlined in the appendix. To make the lead antimony alloys a mother alloy was prepared thus:-A quantity of the antimony (it was received in the powdered form) was placed in a pyrex glass tube, which was closed at one end. The antimony was washed with hot hydrochloric acid (1: 1), then with more dilute acid, then with distilled water, and finally with absolute alcohol; it was dried by warming and evacu,ating the tube. This should leave the antimony more nearly free from surface oxides.The amount of antimony was determined by weighing quickly; the appropriate amount of vacuum-cast electrolytic *Research Fellow, Dept. of Metallurgy, University of Melbourne.

Jan 1, 1936

Laboratory and pilot plant investigations aimed at recovering gold as an electroformed sheet from gold eluate and gold leach solutions and slurries are discussed. The electrolytic test work undertaken makes use of high surface area electrodes, in particular nickel-chrome foam metal and activated carbon, as well as ultrasonic activation. The process involves initial gold electrowinning (or adsorption onto activated carbon), followed by gold electroforming, both operations being carried out in a specially designed reactor. The pilot plant work mainly involved the treatment of gold eluate solutions from a South African gold mine containing 600 mg/L Au: some tests were also carried out on gold leach solutions containing 6 mg/L Au. In the former case, very efficient gold extraction onto the foam metal cathode was achieved using electrolysis combined with ultrasonics. The polarity of the gold-loaded cathode was then reversed and, using a replacement electroforming electrolyte, gold was electroformed in situ onto a polished stainless steel mandrel, from which gold sheet was subsequently removed. In the case of leach solutions, pilot plant tests confirmed laboratory findings that in the presence of calcium (resulting from the lime used during the leaching process) no electrowinning is possible. Laboratory tests showed, however, that when sodium (in the form of NaOH or Na2CO3) is added to the leach solution, electrowinning can indeed take place. Alternatively, if a special activated carbon electrode is used (without current), the non-ionic calcium aurocyanide complex is adsorbed on to the activated carbon. When a gold-loaded activated carbon electrode is made anodic in a gold electroforming electrolyte, gold electroforming is feasible, although the efficiency is very low. The possible implications of these developments for gold recovery are further examined.

Jan 1, 2007

By P Vasconcelos, X D. Deng

Numerous supergene manganese oxide deposits are developed inSouth China as a result of weathering of a thick sequence of Paleozoic marine Mn-bearing sedimentary rocks, consisting mainly of limestones, cherts and black shales that were intensely folded and faulted due to multiple episodes of tectonism since the late Triassic. The ore minerals are dominantly pyrolusite, cryptomelane, nsutite, lithiophorite and braunite. The supergene manganese ores contain Mn ranging from 20 to 44 wt per cent; manganese oxide deposits derived from cherts and black shales also contain recoverable levels of Co, Ni, Cu, Pb and Zn. 40Ar/39Ar dating of potassium-bearing manganese oxides reveals that extensive supergene manganese ore formation started at least in the earliest Miocene and persisted to the Present. Ages of the deposits show a close correlation to tectonic stability, with the oldest in tectonically quiescent areas and the youngest in active areas that have subjected to continuous uplift and thus significant denudation. The prolonged wet and hot climate since Oligocene and the balance between weathering and erosion, which is parameter to the tectonic stability, are the ultimate controls on the formation and distribution of South China supergene manganese oxide deposits. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008