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A study of the accessory opaque iron-titanium oxide minerals of the Oiles Complex, central Australia, was an Important complement to an investigation of the magnetic properties of the Complex. These minerals constitute no more than 10 per cent of the rocks sampled, and generally less than 1 per cent of the ultramafic rocks ("magnetite" concentrations were not sampled for magnetic investigation).Titanomagnetite is the main opaque mineral present, although ilmenite exsolution has been widely developed. High-temperature oxidation of these produced mainly titanohematite, pseudobrookite and rutile. Both exsolution and high-temperature oxidation developed along specific crystallographic directions (along {111}), and in Irregular patches. Low-temperature oxidation is generally not well-developed, indicating the small degree of weathering in the rocks sampled.Although the Oiles Complex is layered, no apparent overall preferred orientation of the iron-titanium oxide minerals was observed, other than crystallographically controlled alignment of very fine grains within pyroxene crystals. Other textural features of the opaque oxides are restricted to symplectic intergrowths mainly with the ferromagnesian silicates.

Jan 1, 1971

By Cunningham CG

Many epithermal gold-silver deposits areknown to occur in the Neogene-Quaternary volcanic complex of the central Andean region of southern Peru, northern Chile, western Bolivia, and north-western Argentina, an area of about 300,000 km2 where these volcanic rocks constitute the dominant cover. Some of the gold-silver deposits were mined during Spanish colonial times, as early as the 16th century,- whereas others were not discovered until the 19th and 20th centuries. The extraordinary gold-silver potential of this young volcanic complex, however, was not recognized until the 1970's when the phenomenal increase in gold and silver prices stimulated new exploration. New discoveries were made, chiefly in southern Peru and northern Chile, of high-grade ores in old mining districts and large low-grade ore bodies, both in old districts and in new areas having no history of mining activity. Many additional gold and silver deposits remain to be discovered within and beneath the young volcanic complex of this region.

Jan 1, 1990

By Williams ID

Ore and coke of various size fractions (1 to 11 mm) were packed in a column (146 ó) and resistance to air flow measured under a range of conditions. Results have shown that layered charging results in an interface having essentially a directional structure the thickness of which is directly proportional to the coke and ore size ratio and whose flow resistance exceeds that of the coke layer many times its thickness. Friction factor - Reynolds number plots showed large positive departure from the Ergun equation for all components investigated whilst functional analysis and that in terms of bed constants, showed a strong dependency of the pressure gradient on bed properties and the actual particle size as well as the size ratio. It is also shown that pressure gradient in mixed beds follows previously reported behaviour and that a directional interface offers higher resistance to flow than a mixed interface having the same volumetric ore/coke ratio. Significance of results to practice is discussed.

Jan 1, 1975

The story of the Penjom gold mine located near Kuala Lipis on the Malay Peninsular demonstrates the valuable role successful exploration companies can play in the development of the gold mining industry. Avocet Mining PLC ('Avocet') began exploration in the area on a limited budget in 1989, securing land tenure around the Penjom alluvial workings in July 1990. The lease granted, known as Block 7, formed part of a land package offered at the time by the Pahang State Government to develop the resources of the area. Until the late-1980s, the Kuala Lipis region, situated approximately 180 km north west of Kuala Lumpur, had restricted accessibility for security reasons precluding serious exploration or mining activity. The situation has changed dramatically in the 1990s, with several foreign explorers active in the Peninsular, targeting old alluvial and underground workings adjacent to the north-south trending Raub-Bentong Suture. Deeper drilling of these prospects has shown there is potential for both small- to medium-scale open pit mining and possibly underground operations, providing companies such as Avocet with an ideal mining investment opportunity.

Jan 1, 1997

E. W. Stutchbury (Internationa~ Oombustion Aust. Ltd.) : Mr. Callcott made particular mention in his paper of erosion in primary air fans which are placed after the mill discharge. He adds that subsequent reduction in plant performance and resulting increased maintenance costs occur. It is generally assumed that this statement is substantially correct as the fan handles the complete output from the mill, but with modern materials, reduction in performance and subsequent .maintenance are not now a problem. This consideration of handling the pulverised coal in the fan is more than offset by the advantage of operating the mill under suction which results in cleaner operating conditions, simpler feeder arrangements and elimination of complicated seals on the mill.and feeder unit. It should be specially noted that whereas mill exhausters in the past have used chequer plate blades (sometimes with the addition of hard facing by electrode deposit) it is modern practice to provide fan blades of up to 1 in·. thick Ni-hard suitablyheat treated, with the circumferential section of the fan also in Ni-hard. By the use of this material large power...

Jan 1, 1957

A programme began in 1970 to eliminate the charging of fine materials into the copper blast furnace of The Electrolytic Refining and Smelting Company of Australia Ltd. at Port Kembla, N.S.W. A disc pelletiser and drying plant has been installed as part of this programme. Feed material for the plant is a blended mixture of copper concentrates, fine copper-bearing residues, and blast furnace cyclone dust. The operating parameters for the disc have been calculated by comparing the perform- ance of three other discs on the plant. Re- search work on choice of binder, feed moisture and drying conditions has led to the production of reasonably high strength pellets. A description of the pellet plant and modifications necessary to overcome the initial performance problems is given.

Jan 1, 1974

Before presenting this address I desire to express my appreciation of the honour which has been conferred on me by my election as iPresident of The Australasian Institute of Mining and Metallurgy. At this stage it might not be out of place to recall that Broken Hill was the birthplace of The Australasian Institute of Mining and Metallurgy, originally formed as the Australasian Institute of Mining Engineers in 1893.In selecting for my address the topic of "The Broken Hill Mining Industry and its Contribution to the Economy of Australia" I realise it is impossible to cover fully every aspect of the nation's economy which owes all or part of its origin to the Broken Hill field. Nevertheless, I feel that some attempt should be made to give credit to the Broken Hill mining industry for its part in the progress which Australia has made over the past seventy years.. If we care to reflect for a moment it soon becomes apparent that, not only is the Broken Hill mining industry an important producer of base metals for domestic and overseas consumption, but its profits have provided the means whereby many of Australia's leading secondary industries have been established or built up. Examples which come to mind are the founding of the iron and steel industry by the Broken Hill Proprietary Company; the establishment of plants at Port Pirie in South Australia, and at Risdon in Tasmania, for the production of metallic lead and zinc; and also at Port Kembla for the smelting of copper ores. From profits derived from operations at Broken Hill, capital has also been provided to assist other new essential...

Jan 1, 1956

Alluvial gold mining is thriving in the Yukon Territory and Alaska. The scale of many operations is similar to those in New Zealand but there is greater government support for research and test work. As a result a great deal of information on equipment for the recovery of alluvial gold has been obtained. This paper is a review of the information with the aim of making relevant data available in New Zealand.

Jan 1, 1989

By I M. Platten, C J. S Sangster, Y Xie

The Cononish gold-silver deposit is a steep, relatively narrow quartz-vein system, with a current total mineral resource of 154 000 oz Au and 589 000 oz Ag. The northeast-southwest trending system was emplaced into late Proterozoic metasediments, and postdates metamorphism and associated Caledonian Orogenic foliations. Assay and mineralogical data show that gold and silver is spatially associated with sulfides in quartz. The main sulfide is pyrite, but galena, chalcopyrite and sphalerite occur in small amounts. Gold occurs as electrum, with minor native gold, and silver occurs additionally as tellurides and native metal. The gold/electrum is fine-grained, generally less than 100 microns in size. The main ore shoots plunge 45¦ south-west, have a 40 m to 80 m intersection with the existing underground development and extend between 40 m and 260 m down plunge. Small-scale sulfide-bearing domains within the vein carry the highest gold grades. They collectively define the ore shoots, where one or two, and rarely three, of the domains are present at an individual site in the vein. Discontinuity of individual domains, variation in domain thickness and internal heterogeneity results in short scale variation in grade across the structure. Geological mapping along a 1.2 km exploration adit has provided critical æconditioningÆ data to support resource evaluation based on development and relatively wide spaced drilling. In addition, it has provided an indication of potential challenges that could be encountered during production.

Jan 1, 2009

The Northland region of New Zealand has a complex geological history which has long been the subject of considerable controversy. Small mineral deposits have been discovered in the past, and some have been mined. Except for aggregates and very high quality china clay, mining is virtually nonexistent at present. Mercury mining is proposed from small deposits in the Kaeo area. Intensive exploration for epithermal precious metals deposits in the past seven years, combined with some recent geological mapping undertaken by the Geological Survey and University thesis students has added greatly to an understanding of Northland's geology. Mapping of the Whangaroa-Kaikohe map sheet at a scale of 1:100 000 by Brown and Laurenson Limited has enabled new geological information to be collated for the first time since 1961, when the last geological map was published. The 'Northland Allochthon' is now observed to be a series of four or more thrust sheets each containing predictable formations. High angle faulting contemporaneous with overthrusting has modified the thrust sheets, and established a series of horsts and grabens. The Pirau Fault is considered to be a major earth fracture.

Jan 1, 1987

The theme of this conference is æRediscover OtagoÆ and the conference occurs during a resurgence of economic activity in New Zealand, and in particular at a time when the Macraes Gold Project has had a significant effect on mining and business activity in Otago. The Macraes Gold Mine has implemented a Zero Accident Programme and this paper reviews some of the factors responsible for the implementation.

Jan 1, 1992

The Project Financing Industry is currently being expanded en- compassing greater competition due to the improved worldwide economy. This has meant that money is in greater supply than demand for both loan and equity investment and is available for larger and higher risk ventures. The consequence of this is that the Project Financing Industry should be better able to provide more innovative forms of financing to meet the needs of mining and petroleum companies, regardless of size. Large mining and petroleum companies in Papua New Guinea should therefore be looking for ways to raise equity funds for exploration in greenfield areas, diversifying their risks through acquisition, and seeking to reduce their costs of borrowings. The small to medium sized mining sector should be looking to raise equity for increased ex- ploration on tenements and, where possible, to raise borrowings to fund expansion and further development of their projects. In summary, it is a period during which companies should take ad- vantage of available funding to augment their strategic plans and increase their long term returns to shareholders.

Jan 1, 1997

THE method depends upon:--1. The position of the mill.2. The space available for stacking the residue.3. The nature of the residue as discharged from the mill.4. The value of the residue for re-treatment.5. The requirement of the residue for underground filling.Originally the conditions in this district varied mainly in the position of the mill, some mills having an elevated site with plenty of dumping space for the time being, whilst others had a flat site, and very little dumping space near at hand; but in most cases the residue discharged was in the form of filter-press cakes, suitable for conveying on belts, or in trucks, and stacking in a high clump; and, while a portion of the residue was used for underground filling, the dump was regarded as a valuable asset, to be re-treated later. Under these conditions, conveyor belts, electric trams, aerial trams, and hose trucks, all gave satisfactory results, and the following figures, taken from "'West Australian Metallurgical Practice," will show how these methods compared as regards costs...

Jan 1, 1909

By T Do, J Siliezar, M Larson

With the expansion of magnetite projects in Australia has come the opportunity to take advantage of newer technologies that were not necessarily available when the magnetite industries of North America and Europe were maturing. One of these technologies is the IsaMill, originally developed for the economic treatment of ultra-fine grind (UFG) duties of Mount Isa Mines. As understanding of the IsaMill has increased, so too has the ability to process coarser feeds while maintaining the same energy efficiency advantage and tight product size distribution that originally made the IsaMill so attractive. In the case of magnetite the hard non-elastic ceramic grinding media is ideally suited to the grinding duty when compared to steel grinding media. The centripetal separator and naturally steep product size distribution curve provide a mill discharge that maximises the critical concentrate grade. This paper analyses the effect of the IsaMill grinding technology on the full-scale Ernest Henry Mine (EHM) magnetite operation along with pilot and lab scale demonstrations of optimisation. Issues encountered and the solutions to maximise the mill throughput and quality are examined in an effort to promote better understanding across the industry. CITATION:Larson, M, Do, T and Siliezar, J, 2013. Enhancing magnetite returns - the benefits of IsaMilling, in Proceedings Iron Ore 2013 , pp 411-416 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By B S. Utting, W J. Cowie

The alluvial gold industry of New Zealand is based on the placer deposits in Otago and on the West Coast. Production from these since discovery in the 1850s has been an estimated 480 t (15 Moz) of gold. Annual output has expanded continuously since 1980 and is expected to be over 2 t of gold for 1989. Following a historical review, the characteristics of typical operations, which use hydraulic excavators and mobile trommel units are discussed. Descriptions are then given of alluvial activities in Otago and on the West Coast.

Jan 1, 1990

BHP Billiton Olympic Dam produces copper cathode, uranium oxide concentrate and refined gold and silver. The operation is comprised of an underground Mine and Processing Plant and is located 560 km north of Adelaide. Water for the operation is sourced from two wellfields located 120 and 200 km from the operation in the Great Artesian Basin (GAB) at a rate of approximately 36 ML/d. Regulatory drawdown limits were established to protect regional GAB springs and are monitored at compliance bores. Drawdown was predicted in the æOlympic Dam Environmental Impact StudyÆ (Kinhill, 1997); however, pumping at higher volumes may have the potential for increased drawdown resulting in a trend towards the compliance limits. In recent years increased usage of water in the Concentrator and Hydromet sections of the Processing Plant has caused excess process water reporting to the Tailings Retention System (TRS). This has resulted in excessive amounts of liquor ponding on the tailings cells with a potential impact being contamination due to seepage of liquor to groundwater. Effective management of water by the operation is necessary to both reduce GAB drawdown and reduce the amount of liquor on the tailings cells. A site working-group has been established to investigate and pursue opportunities to improve the water use efficiency of the operation. This paper will highlight the issue of water management at Olympic Dam and discuss the various options currently being investigated to improve management of this important resource.

Jan 1, 2006

A system for rapid on-line determination of weight percentage coal in slurry and weight percentage ash in coal has been developed at the Julius Kruttschnitt Mineral Research Centre, University of Queensland. The gauging system is suitable for use with coal flotation slurries or slurries having a maximum particle size of about 1 millimeter. The system is based upon measurement of gamma ray transmission; radioisotope sources emitting photons of two widely different energies are employed. The inaccuracies of measurement that would normally result from variable amounts of air entrained in the slurry are substantially reduced by pressurising the slurry to approximately 2MPa (300 psi) using a Mono pump. The equipment can be used to make measurements on more than one slurry stream by pumping streams sequent- ially. The system is being tested at the Peak Downs Mine of the Utah Development Company in Central Queensland. This paper describes the theoretical principles of the gauge design, the experience gained to date in the commissioning of the equipment, including the installation of a PDP 11/03 computer, and the progress made in developing satisfactory interpretations of the gauge count-rate output.

Jan 1, 1978

By A P. Tinnelly

This paper explores the structural/physical and policy based issues that have lead to the apparent resource conflict between Forestry and Mining on the West Coast. Both industries are important to the West Coast and bear many similarities, particularly at the corporate end of the mining scale. However there are very distinct structural differences which set the scene for friction at the boundaries. Examples of how mining impacts upon forestry illustrate where some of the friction arises and provides some insight as to where some solutions are or may be found.

Jan 1, 1996

By D F. S Natusch, R J. Hooper

Recent lignite investigations indicate their potential as a strategic long-term fuel resource. This potential however would be determined not only by lignite quantity and quality, but also by economic, physical and social resources required to support it. The following discussion uses the example of a typical lignite mining operation to review the major resource requirements. While recognising that the implications of supplying those resources may be as important as their actual existence, this paper has purposely omitted such discussion as this will be one of the main target areas for the next phase of investigations.

Jan 1, 1983

By J Langhans, Y Choi, Q Wang, J Y. Baron, P Kondos

Barrick has successfully developed the thiosulfate leaching process to treat sulfidic high preg-robbing ores. The process was developed through rigorous bench test programs and proved in pilot campaigns and demo plant operations. The process uses calcium thiosulfate as a leaching reagent, resin for gold recovery with sulfite/trithionate elution and reverse osmosis as a mean of reagent recovery. The thiosulfate leaching plant is under construction as a brownfield project and the start-up is planned in 2014 at Goldstrike, Nevada, USA, one of BarrickÆs operations.CITATION:Choi, Y, Baron, J Y, Wang, Q, Langhans, J and Kondos, P, 2013. Thiosulfate processing - from lab curiosity to commercial application, in Proceedings World Gold 2013 , pp 45-50 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013