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By Dorricott M. G, McAllister J

This paper is concerned with the application of a probabilistic approach to the risk assessment of mining projects.In current practice, sensitivity analysis is the most commonly used deterministic approach of accounting for the uncertainties involved in mining project evaluation, while Monte Carlo simulation is considered to be the best probabilistic method available for the same purpose. The methodology of the approach proposed in this paper is as simple as that of sensitivity analysis. However, the results obtained can be more comprehensive than those obtained from Monte Carlo simulation. Various important statistical features, such as correlation and skewness, of the basic random parameters can be easily taken into account by the proposed approach. Example studies are demonstrated. Lotus 123 was employed for the associated probabilistic calculations.

Jan 1, 1992

The Ardlethan tin concentrator had dete riorated considerably in metallurgical per- formance, maintenance and plant availability. This problem was compounded by low tin prices and International Tin Council quotas. Mid- 1976 figures were: throughput - 1300 tonnes per day, availability 83% and metal recovery 537. Major problems existed throughout the circuit from crushing to tailings disposal and with morale, staffing, and housekeeping. With the lifting of the quotas in June 1976, management provided funds to implement a major rehabilitation programme and some fifteen major projects, at a cost of about $1.3 million have been completed to date. The change in performance has been dram- atic, and end of 1977 performance figures are: throughput - 1700 tonnes per day, availability 90% and metal recovery 65%.

Jan 1, 1978

By Reilly L, Worner H. K

The EnvIRONment process has been developed to treat steel works dust and organic wastes simultaneously. A pelletised feed is fed into a special DC electric furnace, the pellets becoming immersed in a molten slag above a carbon saturated bath. The iron oxide in the pellets is reduced and carburised whilst the organics are broken down to carbon monoxide, carbon dioxide, hydrogen and water vapour. Volatile metals are vapourised and collected in the baghouse. Over two years of trials in a 100 kg DC electric are furnace has brought the process to the stage where it is ready for commercialisation.

Jan 1, 1995

The BLEG (Bulk Leach Extractable Gold) technique is a semiquantitative measure of cyanide extractable gold contained in a sample. A 5kg sample is leached in cyanide solution for 24 hours and gold is precipitated out of the pregnant solution using zinc and assayed by AAS. The detection limit is reported as ppb (parts per billion). Telfer is located 1300km north north-east from Perth in the Great Sandy Desert. The climate is one of hot summers with irregular rainfall and mild winters. A large portion of the area is covered by aeolian sand and seif dunes with poorly developed drainage, rare outcrop; topographic relief is a maximum of 96m. Poor outcrop and poorly developed drainage render conventional stream sediment sampling and soil geochemistry inadequate. Therefore a technique providing a minimum number of samples with maximum accuracy and sensitivity was needed. Consequently BLEG orientation surveys were conducted over the Telfer Mine area in 1983, 1984 and 1985.

Jan 1, 1988

In any strip coal mining operation the aosL important single operating unit is the dragline. Because the capital and operating costs of a dragline are high, it is desirable to operate these machines at their maximum efficiency. Thiess Bros. Pty. Limited operate a Bucyrus-Erie 1350 Walking dragline at their Callide coal mine. The operating conditions at the Callide Mine are different from those of other coal mines situated in Central Queens ,nd. The topography is rugged, the coal seam is thick, and the overburden is hard and inter- HH,inded. Several different operating techniques for a large dragline working under these con- ditinns arc discrossmd it tt

Jan 1, 1978

By K Marler

The Water Act 2000 includes provisions to manage the take of overland flow water. Overland flow water is water that runs across the land after rainfall either before it enters a watercourse, after it leaves a watercourse as floodwater, or after it rises to the surface naturally from underground. To ensure adequate environmental flows and long-term security for water users, it is necessary to balance the amount of water taken as overland flow water and the amount left to flow into watercourses. A water resource plan made under the Water Act 2000 establishes the basis for the sustainable management of this type of water. Of the water resource plans that have been prepared for Queensland catchments, six include provisions to manage the take of overland flow water. This paper discusses some of the common features of these plans and the management approaches adopted. The paper identifies and explains key aspects of the Water Act 2000 framework for managing the take of overland flow water by the mining industry. In particular it explains key concepts of this framework, such as the ability to take overland flow water using existing works, uses of overland flow water that a water resource plan permits, situations where a specific entitlement under the Water Act 2000 is required, and the means for controlling works that take overland flow water. Future initiatives for the regulation and management of overland flow water are then identified and particular challenges for the mining industry associated with using overland flow water highlighted.

Jan 1, 2006

By R Gilbertson, N Freeman

Metallurgical accounting is key to the control and production planning process of any mining operation. This is even more crucial for complex operations involving mining, concentration, smelting, refining and marketing. The tracking of multiple metal product and contaminant components through the operation can improve process predictability and inventory management. Appropriate use can be made of æhigh quality dataÆ for strategic reserve utilisation, mining operations, milling operations, etc. This information enables the optimisation of all aspects of the mining and processing operations. This case study discusses a metal balance implementation for WMCÆs Olympic Dam operations; a large integrated mining, concentration and refining operation, which used an existing off the shelf statistical data reconciliation package developed for the oil industry. It was extended to track and balance the metal co-products across the entire integrated mining, mineral processing and refining plant. The key benefits discussed are tight integration with existing data collection systems, formalisation of previously informal processes, and leveraging the development and support available for a widely used package. The project provided a solution for the site metallurgical balance spanning the mine and processing plant. The solution facilitates a bridge between the planning and production worlds, using a common data model across the site.

Jan 1, 2002

Thermal Processing of Petroleum Fly Ash for Vanadium Recovery

Sep 13, 2010

Alternatively are they a necessary evil'? Exploration geologists are a much higher profile group but then again the higher they are the bigger they Bill. At a mine site they are reluctantly being accepted as equals by mining engineers given the requirements of the `Code' in the reporting of Ore Reserves. How best can mining geologists service their customers? Are more revealing questions to be answered in who are their customers? In the past mining geologists lived isolated existences pouring over plans and sections, now with user-friendly software packages available and the use of LAN, mining geologists and mining engineers talk electronically - God forhid what the future might hying - they might even talk to accountants and metallurgists!

Jan 1, 1997

By Barnett J. C

The arid and semi-arid region of Western Australia occupies about two-thirds of the State equivalent to an area of about 1.8 million sqkm. Groundwater demand in this area has historically been linked to the pastoral andmining industries commencing with the gold discoveries in the Eastern Goldfields some 100 years ago. Substantial increases in demand have occurred in the past two decades initially as a result of nickel discoveriesin the early 1970's and more recently the rapid resurgence of the gold mining industry. Mineral exploration and development in the Great Sandy Desert at Telfer (gold) and Kintyre (uranium) and in the Great Victoria Desert at MulgaRocks (uranium) has also been accompanied by detailed groundwater investigations.

Jan 1, 1988

By Matsumura T, Takematsu T

The Brown Coal Liquefaction Process (BCL Process) has been developed by Nippon Brown Coal Liquefaction Co., Ltd. (NBCL), and a 50-ton-per -day Pilot Plant has been partially completed and put into operation by Brown Coal Liquefac- tion (Victoria) Pty., Ltd. (BCLV) at Morwell, Victoria, Australia. This Project has been sponsored by New Energy Development Organization (NEDO), an or- ganization associated with MITI, and has been promoted as a National Project with funding by the Japanese government. This project has also been conducted as a cooperative technology de- velopment project between the Japanese and Aus -tralian governments since 1980 and has been supported by the Victorian state government and

Jan 1, 1987

Australian continental crust has accreted and consolidated by thirds: 1/3 during Archean time, 1/3 during Early to mid- Proterozoic time, and 1/3 during latest Precambrian to mostly Paleozoic time. The progression of orogenic systems and the crustal consolidations they represent seem not fundamentally different in basic orogenic processes from better known Mesozoic-Cenozoic examples in that accretionary, continental margin, collisional, and intraplate intracratonic inverted and/or reactivated systems are all recognizable in the tectonic evolution of Australia.

Jan 1, 1995

FOR some years past it has been usual to specify high-grade copper for use for many purposes, but the practice of specifying zinc of a high degree of purity for certain purposes is of comparatively recent origin. It is a practice, however, which is extending ag the effect of the impurities in zinc on products manufactured therefrom becomes widely recognized.The notes hereunder are intended to briefly survey the principal uses to which high-gr.ade zinc is being put, and, wherever possible, to indicate the effect of the impurities normally present in the lower grades of zinc.In the United States zinc is graded into five divisions, known respectively as "High-grade" "Intermediate" "Brass Special" "Selected," and "Prime Western." The maximum amounts of impurities allowed in the various grades are indicated in Table I,which is compiled from data published by the American Society of Testing Materials:In addition, it is specified in an cases that the slabs shall be reasonably free from surface corrosion or adhering foreign matter. Although zinc used in Europe has in many cases been sold on analysis it is only recently that any attempt has been made to grade...

Jan 1, 1923

By Taylor MN

The influx of an industrial environment into or adjacent to the indigenous society has in the past frequently caused the breakdown of traditional be- haviour and culture, and the generation of social and psychological impacts on the local population. Successful programmes developed by government agencies and private industry have been implemented in many areas to maintain the cultural environment and still afford the needs for industrial development. The ultimate goal of such programmes should be directed toward eventual operation and management of the established industry by the local population.

Jan 1, 1978

By T Amiconi

Ernest Henry Mining commenced operations on its copper-gold project in August 1997, some two months ahead of schedule and ten per cent ($35 million) under budget. The mine is located in the highly prospective Mount Isa/Cloncurry mineral district in north-west Queensland, approximately 38 km north-east of Cloncurry. The developer and operator of the project is Ernest Henry Mining Pty Ltd (EHM), an incorporated joint venture between MIM Holdings Limited (51 per cent) and Savage Resources Limited (49 per cent). The deposit is located approximately 40 km north of Cloncurry in North West Queensland and lies beneath a featureless black soil plain with no significant creeks or gullies cutting across the site. Vegetation is sparse and consists essentially of Mitchell grass with occasional low shrubs and trees. Up to nine million tonnes of ore and over 43 million tonnes of waste will be extracted each year from an open pit operation to produce approximately 350 000 tonnes of concentrate when in full production.

Jan 1, 1998

By F Palkovitz, S Wilson, F Felipe

The management of waste from mining operations is a significant aspect of bringing a mineral commodity to final market. The ore beneficiation process and transport/disposal of waste involves significant consumption of costly resources. A number of options exist to dispose of mill waste on surface and as a backfill material. These range in complexity, risk, capital cost, operating cost and ultimately business performance. This paper discusses the value delivered to a business in using dewatering systems including paste as opposed to conventional slurry tailings disposals. This is illustrated through various case studies and serves to demonstrate how paste can add value and reduce risk to a successful business.

Jan 1, 2009

By J Nemcik, E Baafi, I Porter, G Spinks

Spray-on liners used in the mining industry for ground support and stabilisation applications are either cement based (æshotcreteÆ) or polymer based (æthin spray-on linersÆ). Some thin spray-on liners are a blend of both polymer and cement (eg Tekflex). A small number of thin spray-on liners (TSLs) have been trialled in Australia as potential replacements for steel mesh in roadways and other underground mining applications; however, they were found to cure slowly and the cured coatings became brittle after an extended time in place. The University of Wollongong in collaboration with the Australian coal mining industry has shown that a viable polymer-based alternative to steel mesh in underground roadway support applications can be developed to eliminate the use and handling of steel mesh. The work to date has: established the feasibility of developing polymeric alternatives to steel mesh in underground roadway support applications; identified the physical and material constraints to be endured by any new polymeric skin reinforcement system by measuring the mechanical properties of steel mesh; identified materials that can be spray applied; and demonstrated that polymer mechanical properties can be optimised to produce similar mechanical properties (elastic modulus, yield stress, elongation-at-break, etc) to steel mesh. The identified materials will: allow the face support cycle to be fully automated, or at least remotely operated and installed; remove personnel from the immediate face area; and substantially improve underground roadway development rates.

Jan 1, 2008

By T E. Norgate

Salinity in Australia is caused by over irrigation and land clearing for agricultural use over the last 100 years. It is now the biggest threat to the quality of land and water in the Murray Darling Basin and Western Australia. Pumping the saline waters straight into the ocean or transporting the solid residue (mainly sodium chloride) to the ocean after evaporation of the water is expected to cost the taxpayer millions of dollars every year. This paper proposes that the salinity problem of Australia, at least in part, can be converted to an asset rather than a liability if it is exploited and used to make value-added products. The more value made out of saline waters, the more saline water is processed and therefore the more salt is extracted from the land. The value-added products that can be made out of saline waters are numerous and diverse. Rough calculations show that value addition to the saline waters could potentially generate up to $A 200 million per annum business in the Murray-Darling Basin. Although it is a challenge to make cost competitive products and find markets for these products it is possible that up to $A 100 million per year may be gained from import substitution. Value addition to salinity would also reduce the threat on the environment and existing agricultural industry. Investment to add value to salinity will create business in the region, nurture the local small population communities, and increase services and long-term employment.

Jan 1, 2002

The Vera Nancy orebodies, although simple in overall geometry, are in detail generally narrow, multi-veined and fluctuating in width, strike and dip. Tight geological control is required to optimise gold and silver production from this bench stoping operation. The processes used to model the resource and to control ore drive development have evolved since mining commenced in 1997. Grade control is a combination of orebody sampling, geological data collection, understanding orebody geometry and the optimisation of ore driving and stoping activities. Global resource modelling utilises mainly drill hole data which is largely superceded by drive development data as stope development progresses. The orebody has a relatively low nugget effect that assists in grade estimation. Rather than rely on sophisticated grade interpolation methods, resource estimation to-date has focussed on developing the geological understanding of the orebody to ensure the framework for estimation is correct. Drill data alone is not adequate to define deposit geometry for stoping . Drive data is used as the dominant data set for stope geology modelling once development for a stope is complete.

Jan 1, 2000

By Fuller P. G, Dugan K. J

Artificial support can be used to improve wall stability in open pit mines. This is examined for a particular case where the factor of safety for a slope is kept constant by using artificial support as the slope angle is increased. It is demonstrated that the savings in excavation generally exceed the cost of support. However, in order to correctly judge the eco- nomic impact of artificial support on the project, all the elements relat- ing to the use of artificial support must be taken in account.

Jan 1, 1989