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Discounted cash flow (DCF) methods are well suited and recommended as a primary valuation method for mineral assets for which there are at least indicated resources and some form of feasibility study containing engineering, production and capital and operating cost data. DCF methods are also applicable as a secondary or check valuation method for exploration properties for which no technical study has been prepared. For projects where little or no engineering, production and/or cost data is available, the process of formulating a project concept by specialists who do not possess experience and expertise in the relevant technical faculties is totally rejected as a basis for applying DCF techniques as a primary valuation method. Such an approach runs counter to The Australasian Institute of Mining and Metallurgy (AusIMM) requirement to apply relevant expertise to specific aspects of mineral valuation. Technical and commercial inputs to mineral valuation should be reviewed by specialists who have specific expertise in the relevant disciplines, and should be tempered by the quantity and quality of technical evaluation which has been undertaken and the development status of the asset.

Jan 1, 1994

Research and Technical Services, Department of Mines Western Australia The nine papers received for this technical session cover a very wide range of hydrological problems in various parts of the world. Three of these papers deal with hydrological predictions for new mines, while three are concerned with the prediction of water chemistry. The three remaining papers deal with gas injection as a dewatering tool, discharge formulae verification and the use of a physical model to predict subsurface strata movement and fracture development due to longwall mining. Hydrological problems in mine planning represent a major risk in many mining operations, booth as a potential life or equipment hazard and a major financial risk. The initial paper selected to review was therefore one by the president of a gold mining company, rather than by one of the specialist scientists, to remind us all that the main reason problems are faced and overcome in the mining industry is usually a commercial one. In one commercial undertaking, the ability to accurately assess future risk is a highly desirable planning tool and hence in mining, the ability to predict the nature and magnitude of hydrological problems is n i-an varxi imnnrfant

Jan 1, 1988

By Brinkmann J. R

The relative effects of the two basic mechanisms contributing to rock breakage during blasting, shock and gas penetration, are neither well understood nor well characterized, and need further clarification. Blasthole liner (BHL) tests separate the two effects, and by enabling direct measurement of borehole expansion give insight into the shock/gas energy partitioning in rock confinement. The hydrodynamic code DYNA2D is used to simulate the shock effect of the detonation of emulsion in a stainless steel lined hole, and the predicted expansion is compared with experiment. Workers in the past have neglected near-blasthole phenomena and have calibrated models based on stress measurements remote from the blasthole. Extrapolation back to the blasthole has inherent limitations, and indeed, one of the deficiencies of these models is that they have not been able to predict correct borehole expansions, as observed in BHL experiments. DYNA2D has been enhanced by the ICI group with a detonation model which resolves the explosive reaction zone. As a preliminary step towards the ultimate goal of devising a practical damage model, simulations are used to predict the maximum expansion that would take place if the rock were to remain undamaged. Various material parameters are investigated and it is shown that calculated liner expansions are appreciably lower than measured values for high rock yield strengths, while greater than values for low yield strengths.

Jan 1, 1990

After the minim operation, most raw materials that occur in the earth's crust require some form of processing or refining before they can be converted into a final end product. In the mineral industry these remarks apply to materials such as iron ore, bauxite, limestone, copper ore and many others that are found in Australia in large quantities. Processing plants for these raw materials operate more efficiently, however, if the feed to them is consistent in both physical and chemical characteristics. Such uniformity rarely occurs in nature so that some form of homogenisation, or blending, is required ahead of the processing plant. Bending also assists the mining operation itself by reducing; the need for selective mining and, by combining high and low grade materials, a more uniformly graded, commercially acceptable product can be obtained, thereby increasing the commercial life of a mine or quarry. Bed blending is the most efficient of the processes available, and following its development in the United States in 1905, over 100 plants have been installed, or are under construction, all over the world. The original process, the Robins--Nessiter system, has been the subject of continued improvements and refinements, so that economical capacities are possible from less than 100 l.t.p.h. up to 10,000 l.t.p,h. and beyond.

Jan 1, 1969

In contrast with mining in areas close to the main centres, mining in remote areas is characterised by comparatively high initial investment and relatively high running cost for the life of the mine. This is because of:the real cost of establishing and running the operation at a location distant from the necessary infrastructure; and the perceived risks priced into their costs by the multitude of suppliers involved in the project. Optimal co-operation between the mine and the supplier in developing the right rela tionship and the correct technical solution permit both cost elements to be reduced. This re duction may well mean the difference between success and failure. This paper examines the possibilities for optimising the contribution of the equipment supplier to the overall success of the process. Issues covered include the necessity to provide more than merely equipment fit for the purpose , but also the need to maximise the benefits of equipment ownership over the life of the mine. A simple method of determining the optimum timing for equipment replacement or rebuilding is proposed . Furthermore the maintenance contract (or performance agreement) is suggested as a means of leveraging the supplierÆs commitment to the mining operation. The specific examples are based on experience with mobile equipment but the methodology has relevance to other equipment and supplies.

Jan 1, 1998

A unique set of circumstances has devel oped in the Mt. Newman Mining Co. Pty. Limited's project in the Pilbara because the mining town of Newman was built almost entirely by the Company whereas residential areas built by the Company at Port Hedland were developed as an adjunct to an existing town. The following discussion points out the different problems which have been developed in the two areas, even though basically the stand- ard of housing and general amenities is the same, and the means taken to overcome these Problems.

Jan 1, 1973

Australia today is one of the leading countries in the fields associated with the mineral industry, an industry which accounts for over 50% of overseas income and revenue to government. This is no accident. In order to be competitive in what was recog- nised very early in the country's history as a highly profitable busi- ness, the Australian mineral industry (mining, extractive and refining metallurgy) has traditionally been very innovation con- scious, a characteristic which has been evident from the begin- ning of the industry or very nearly so: Australia's geographic isolation and the dispersion of the mineral industry over wide distances made an exchange of ideas difficult and often impossible. One needs only to look at the inaugural address given by Sir Henry Ayers, the first president of the then Australasian Insti- tute of Mining Engineers, in Adelaide on 4th April, 1892 (1) "There is probably no other pursuit which depends more on its productive development and profitable results than in the extent and application of the scientific and mechanical knowledge possessed and exercised by its manager." and "Having in view the value of the mining industry of Austral- asians, they should be urged to apply their best skill with all the scientific and mechanical knowledge obtainable to its future development."

Jan 1, 1988

By Lee H. G, Li H, Hayes P

Slag from the smelting of lead can contain up to 20 per cent zinc as an oxide. An understanding of the lead smelting process and of the subsequent fuming process for the recovery of zinc is enhanced by a knowledge of the activity coefficient behaviour of zinc oxide in smelting slags. The literature presents a wide range of contradictory values. This paper critically reviews the published data and outlines new measurements being made by the authors. A consistent set of zinc oxide activity coefficient data is presented for liquid slags within the ZnO-'FeO'-CaO-A1203-SiO2 system, through a combination of present and previous measurements.

Jan 1, 1993

Spatial continuity as described by a variogram is a reflection of the underlying mineralisation/geology. Modelling of the spatial continuity (variogram) must account for both the quantitative data (ie sample grades), on which the variogram calculations are based, and the qualitative information as provided by the geological interpretation. An understanding of the geology and the variogram interpretation tie together the sample values and allow us to go beyond the actual data (Journel, 1995). Variography makes geology transportable and allows the geological interpolations to be channelled downstream into mine planning, ultimately affecting the economic decisions surrounding a deposit. As such the process of variography and resource modelling is critical. Thus consistent expert decisions need to be made which force geologists to have a closer look at the available information and the geological interpretations. The aim of this paper is to provide an overview of the latest developments in visualising variography and to demonstrate their usefulness in decisions regarding the spatial continuity of mineralisation. New ideas concerning potential future developments in visualising and modelling spatial continuity through variography are introduced.

Jan 1, 1996

The Goldfields extend from Norseman in the Eastern Goldfields to Marble Bar in the Pilbara; a distance of approximately 1,500 km. (Figure 1). Tailings dams are conspicuous on the relatively flat and featureless Goldfields' landscape. They impound wastes from mining and processing operations. Tailings dams interact dynamically with their environment and progressively consolidate as water is removed. Water recovery systems have been used over the last decade to improve water conservation, increase dam stability and to extend the service life of the dam. Without water recovery, dams would need to be significantly larger to permit the tailings to dry back sufficiently to support subsequent depositions. The paper reviews inter-relationships between the tailings dam and its environment and discusses water recovery systems, that are commonly used. The effectiveness of water management is illustrated by reference to seasonal water recoveries measured by Western Mining Corporation (W.M.C.) at their number 2 dam at Kambalda.

Jan 1, 1988

Successful management is ultimately measured by return on shareholders' funds. This is the inescapable and inexorable discipline that ultimately rules every investment. Shareholders today are predominantly, and increasingly, the superannuation funds and insurance funds of almost all of us. We have already reached the situation in Australian investment history in which the best interests of employees can be very directly identified with the best interests of the owners of the capital invested.

Jan 1, 1992

By B Lavin, R Sanford

This paper examines the application of Lean Manufacturing in a mining environment, based on experience within the Rio Tinto entities: Rio Tinto Aluminium, Northparkes Mines and Hunter Valley Operations. The three applications have tested the flexibility of the Lean methodology. Within Rio Tinto, Rio Tinto Aluminium was the first group to introduce Lean. The rollout began in late 2004. It was introduced firstly at Boyne Smelters, Gladstone, as a model site with the initial application in the Carbon Bake Furnace area. It was later extended to other sites including the Weipa Bauxite Mine. LeanÆs successful application within Rio Tinto Aluminium was in part responsible for its recent adoption by other Australian-based Rio Tinto business units including Northparkes Mines, a copper mining operation in Central New South Wales, and Hunter Valley Operations, a group of four coal mines in the Hunter Valley region of New South Wales. Lean is also being adopted by Rio Tinto Iron Ore. Rio Tinto Aluminium introduced Lean Manufacturing to complement an existing Six Sigma business improvement program and to achieve continuous improvement activities at a workplace level. Lean provides a similar level of rigour and discipline to Six Sigma but its application is everyday and for everyone, everywhere in the workplace. It is a valuable management tool. In a short time, Lean has achieved good and sometimes spectacular results improving productivity and efficiency at all sites, including our mining site. Within Rio Tinto Aluminium, it has also had beneficial impacts on our ability to develop and retain employees.

Jan 1, 2006

The explosion of a charge in a drillhole sets the surrounding rock mass into vibrating stress wave motion. Except in the immediate vicinity of the drillhole, the dynamic stresses associated with this motion do damage only to pre-existing joints, cracks, or other weak planes, not to the rock material in between these. The joints are weak in tension, therefore the damage occurs as a result of tensile stresses. The initial damage process in the rock mass that ultimately breaks loose in front of the hole is similar to that in the remaining rock behind the drillhole. Recorded or calculated values of the vibration velocity and frequency contain a wealth of information about the combination of stress and strain that causes the damage. This paper outlines a new technique by which the peak strain energy derived from measured or calculated vibration velocity records is used to determine the local fragment size distribution. It combines two previously known and well tested techniques, namely the Holmberg-Persson calculation of the peak vibration velocity generated by an extended charge and King's calculations of the fragment size distribution as a function of the strain energy in rock crushing. Both of these calculations are based on experimental data and have been tested and found to agree well with actual conditions in their respective fields. Holmberg-Persson's calculated peak vibration velocities have been used successfully to predict and control damage to the remaining rock in cautious blasting, while King's calculation successfully describes the comminution of rock in mechanical crushing. Preliminary predictions of fragmentation in two types of rock blasting, a large hole open pit mining blast and a tunnel round, indicate that the new technique for fragmentation prediction has the potential for predicting fragment size distributions within the rock removed by the Blast.

Jan 1, 1995

Mining, like most other businesses, is based upon capital assets; and the primary cap- ital of any mining company is its ore reserve. A company's survival and growth is, thus, dep- endent upon its ability to replace, increase, redistribute and to diversify its ore reserves. A Kennecott executive addressing a group of geologists in 1957 stated, "Management expects a geologist to find ore! That is the primary objective and the justification of the geologist in the minerals industry. There is no other function that we can rationalize." This is, however, a restricted point of view, and one which I an sure is not fully shared by mining executives or mine operators at the present time. Ore reserves are 'made' as well as 'found' and the geologist contributes to this process. A mining geologist engages in activity in- volving the study of geology in connection with the total mining operation. His major task is the adaption of geological knowledge of ore de- posits and rock behaviour to mining needs, and the application of principles of the science of geology to specific problems of finding, develop- ing and extracting of ore bodies.

Jan 1, 1975

By Opitz E. A

The integration of environmental and permitting strategies into development has become a routine part of doing business for the international minerals industry. Paralleling the development schedule with the environmental and permitting schedule is critical to ensuring that design recognises environmental constraints and that the environmental and permitting program has the right focus and achieves the objective of obtaining workable permits that reflect the project design. Regulatory issues including the law of and controls established by the country the project is situated in, the requirements of international financing institutions, international politics and the role of environmental groups and the particular precedents and processes established are all important issues that must be recognised and incorporated into the permitting program by the developer. Technical issues including collecting early environmental data during exploration, establishing hydro-meteorology equipment, baseline data gathering, and getting good environmental engineering information as a part of feasibility and design are also critical issues to the success of a project which are under the direct control of the developer. Finally tying all of these issues into a single integrated strategy under the direction and control of a nominated team is necessary to maintain focus and achieve results.

Jan 1, 1997

By Peters S. G, Beams S. D

CONCEPTS AND REGIONAL GEOLOGY The Charters Towers region holds many keys to the metallogeny associated with the complex geological development of eastern Australia during the Palaeozoic. Tectonic, magmatic and volcano-sedimentary depositional episodes can be identified and related to the chronological development of batholithic host rocks (Clarke & Paine, 1970; Henderson, 1986; Murray, 1986). Pre-batholithic basement rocks in the north (Charters Towers Metamorphics) consist of a package of amphibolite grade schists interlayered with and intruded by gabbros and diorites (Peters, 1987). To the south (Seventy Mile Range Group) greenschist facies Cambro-Ordovician rocks overly some of the basement. The lower age of this basement is not constrained, parts of it could be as old as Pre-Cambrian. Mid-Ordovician (approx. 470 my) to Lower Devonian (approx. 400 my) age I-Type granitoid plutons of the composite Ravenswood batholith intrude the pre-batholith basement and the Seventy Mile Range Group. Igneous activity was initiated again in the Carboniferous with the extrusion of rhyolitic lavas and pyroclastics associated with porphyry and high-level intrusive complexes (Wyatt et al., 1971). The Ravenswood block is bounded by Devonian and Tertiary sedimentary sequences of mainly continental provenence.

Jan 1, 1989

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

By Robertson A. D C, Cranfield L. C, Murray C. G

Most base and precious metal mineralisation in the Gympie Province is genetically linked to intrusion of branitoids of Late Permian to Late Triassic age. Most lodes are hydrothermal quartz and quartz-calcite veins at intrusive contacts, within either the granitoids themselves or the country rocks, and commonly associated with dykes. Other types of intrusive related deposits are disseminated porphyry type Cu, base metals in skarns, and Mo in quartz pipes and veins. Although the Late Permian-Late Triassic granitic intrusives can be subdivided in terms of age, it is not yet possible to relate deposits of particular metals or styles to granites of a specific age on a regional scale.Some significant mineralisation is not associated with granitic intrusions. This includes the Gympie goldfield, by far the largest known deposit within the Gympie Province. Gold occurs in quartz veins crosscutting Early Permian volcaniclastic sediments and also in NW striking fault zones. The source of the mineralisation is unknown. Gold and silver also occur in epithermal, disseminated and breccia hosted deposits within Late Triassic continental volcanics. Epithermal Hg mineralisation at Kilkivan may be related to Early-Middle Triassic volcanics.

Jan 1, 1990

By Szwedzicki T, Jiang J

The acoustic emission (AE) technique has found wide application in rock engineering. Generally, acoustic emission, which is produced by a rapid microcrack growth, is an ubiquitous phenomenon associated with brittle fractures and can provide information on the failure process in rocks. The sudden release of stored energy in the form of an elastic stress wave that travels from the point of origin within the material to a boundary is called an AE signal or a discrete AE event. Based on a number of experiments and analysis, the correlations among the rock type, the complete stress-strain behaviour, mode of failure and AE properties are investigated and the AE pattern has been classified as four types: single-peak AE, double-peak AE, continuous AE and absent AE. Each type of AE pattern corresponds to a certain type of rock and is largely related to the internal structure and imperfection of a rock. Applications of the AE technique in stability monitoring, in situ stress assessment and seismic source location are also discussed.

Jan 1, 1995

It is very apparent that the hydrogeotogicat characteristics of mineral deposits in China be dominated by meteoric factors, terrain factors and the kind of karstic aquifers as a main source threatening the mining.The hydrogeotogicat characteristics of mineral deposits in dry areas are very different from that in non-dry areas.The rote of precipitation is very important to mine dewatering.The difference of water recharge condition of a mineral deposit located upper (or under) Local erosion basis is existing. There are more than two million square kilometers of carbonate in China.Many water-bearing deposits are distributed in it.According to the karst shapes the surrounding karstic aquifers of mines can be divided into three kinds including solution fissure aquifer,karstic cave aquifer and underground stream (karst stream) aquifer. Underlier invasion is a main feature of karst water-bearing coal mine and upper tier incoming is a main feature of skarn copper and ferro mine.Swatlor pillar and collapse is a special feature of karstic water-impregnated mine.

Jan 1, 1988