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The investment worth of a mineral deposit can only be realistically evaluated in relation to specific engineering design criteria, which fully details the proposed method of exploitation. These criteria have not in general been taken into serious consideration when leaseholders have reported reserves in the past. In fact, many "reserve" figures quoted are probably more correctly classified as geological resources. The industry now recognises that it is necessary to take into consideration not only grade and mill recovery factors, but also likely mining and processing costs as well as the current market price for the commodity. Once having estimated those costs which are applicable to the resource under study, they can be deducted from the gross inherent worth of the orebody to result in an estimate of the potential net revenue. Through a process of interactive trial mine designs and evaluation, reserves can be quantified to provide an estimate of the available recoverable economic reserves given a set of assumed cost and operational parameters. It follows then, that the available economic reserve recoverable from a given resource will vary from time-to-time as cost and price factors vary in response to changing technology and economic factors. A methodology is described which may be used to derive economic recoverable reserves based on a computerised model of the geological resource data and appropriate economic and operational cost algorithms. Examples are provided from both coal and gold studies to illustrate the impact of economic criteria on the magnitude of the reserve figure reported for each project.

Jan 1, 1987

The first 12 m diameter rakeless thickener in the Australian gold mining industry was installed to treat plant tailings at the St Ives gold plant in April 2000. The plant processes approximately 3.2 M tonnes of ore producing about 430 000 oz of gold per annum using conventional crushing, grinding, gravity and carbon in pulp processing methods.The main benefit sought from the thickener was to improve water recovery in the plant and provide water for a 55 000 oz per annum heap leach operation. The thickener design indicated that more than 128 m3/h of overflow water could be returned directly into the plantÆs water circuit, relieving the demand on the borefields. The resultant surplus in the water circuit would then be available for the heap leach project. Based on laboratory and pilot plant scale tests conducted by EIMCO the thickener was designed to handle up to 700 m3/h of tailings slurry (450 tph of solids) with a 40 per cent oxide component in the ore blend. The normal plant throughput is 565 m3/h of slurry (400 tph of solids). Gold mineralisation in most areas at St Ives comprises quartz-sulphide vein and breccia lodes with common albite-biotite-chlorite alteration assemblages. There are well developed supergene gold horizons in the clay-oxide profile above most of the deposits (Osborne, 2002). This results in a wide variety of ore types being treated. At times 40 - 50 per cent of the ore may be oxide in nature. After some commissioning difficulties associated with instrumentation, the thickener has performed satisfactorily although it has not reached its design capacity. The maximum density achieved under normal operating conditions with 20 per cent oxide ore is about two per cent below the design. The thickenerÆs performance deteriorates further with increasing amounts of oxide ore in the blend. The thickener has provided sufficient water for the successful operation of the heap leach and has also provided some down stream benefits for the gold plant by way of pH and cyanide conditioned thickener overflow water.

Jan 1, 2002

By Collins J. L, Fytas K

Surface mining accounts for more than 50% of the world's total mineral production. In future years this status is expected to change somewhat in favour of surface mining. The production technology during the past decade has concentrated on greater degree of mechanization with high capacity heavy duty equip- ment. This trend will continue. Next two decades will also see microproces- ,or based equipment, health and performance monitoring and management information systems fully integrated with excavated and material handling systems which in themselves will be amenable to auto- matic and remote control. Computerized mine planning will also be integrated within the system providing a fully integrated planning, excavat- ing and materials handling system. The surface mines of the 1990's and beyond will be so computer dependent that manpower will be reduced to one third of current levels.

Jan 1, 1988

By Meyer C. F

The increasing use of continuous miners in the extraction of high coal seams has amplified the need for enhanced ventilation systems in the headings. Owing to larger face dimensions and higher production rates, more ventilating air is required to effectively dilute liberated methane to acceptable concentrations. However, the increased air quantities raise and entrain greater amounts of dust, to which the operator is subjected. Various methods (eg sprayfans, on-board scrubbers and jet fans) are used in various configurations and combinations to ventilate the headings. These arrangements generally result in a complex air flow pattern, which complicates achieving an optimum balance between diluting methane and minimising dust capture. In order to cost effectively investigate and propose solutions to this problem for the South African coal mining industry, the Division of Mining Technology has embarked on an extensive work program to evaluate various ventilation methods presently in use. Four currently generic ventilation patterns in various heading scenarios have been simulated using the Computational Fluid Dynamics (CFD) computer program. Evaluating these outputs against a predetermined set of criteria allows the best system for a particular situation to be chosen. The program also facilitates fine-tuning of an adopted system without incurring the cost and inconvenience of doing such tests in situ. This process not only provides solutions at significantly reduced costs, but also yields deeper insights into the factors affecting heading ventilation than hitherto possible.

Jan 1, 1995

A schematic overview of the variables which interact to determine ore reserves precedes consideration, in this context, of some recent views on the concept of a 'production cycle'. Political and governmental action, for whatever motives, is a greater obstacle to future mineral supply than technical problems.

Jan 1, 1979

This paper describes some research attempts to isolate factors associated with lost time accidents and attitudes to safety. Some results of these investigations are presented and their implications discussed. Proposed future research is outlined. Error analysis and the importance of organisational variables are briefly mentioned.

Jan 1, 1975

Monazite sand is processed at the rate of 25-30 tons per week at Rare Earth Corporation of Australia's plant at Port Pirie. Main products are rare earth concentrates of cerium, lanthanum and yttrium. By-products are commercially pure water soluble thorium sulphate and tri sodium phosphate. The more recent developments in volume rare earth applications are Discussed.

Jan 1, 1972

By Giannini L. M

A method using dynamic programming for solving the optimum pit limit problem was presented in an earlier paper. A recent issue of this journal contained some contributed discussion on the implementation of this technique. In this paper we provide some additional ideas and possible options one can incorporate into the method. In particular, an efficient procedure for obtaining further optimum pit outlines on extensions of the original block model is described.

Jan 1, 1987

By Agrawal R. D, Kapoor M. L

Activity of FeO in the ternary system MgO-FeO-CaO in contact with metallic iron has been measured at 1000 K employing the cell.PtIFe, (Mg, Fe, Ca)OIZr02 - CaOIFe, FeOlPt. Measured data are used to study the phase stability relations in the system MgO-FeO-CaO and an isothermal section at 1000 K through this system is drawn.

Jan 1, 1987

By N C. White, C M. Allen, I H. Campbell

Porphyry Cu-Mo (Au) deposits of southern and western China are localised in ancient arc environments and continental-collision orogenic belts. Despite the contrasting tectonic setting, the known deposit geology and geochemistry appears identical in both. As such, the application of existing ore deposit models to atypical collisional settings suggests that significant potential exists for future discovery of significant porphyry deposits throughout the accreted cratonic blocks of Asia. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

The B.H.P Company has been using shortwall mining methods for the past six years in the Southern Field. several aspects this experience shortwall equipm H.P. Company has been using shortwall mining methods for the past Northern Collieries and for several years at Corrimal in the Various papers have described and assessed that work. There are of recent work which supplement prior publications. The summary of to date is a background to discussion of the role of self-advancing ent in support in pillar extraction.

Jan 1, 1974

By Peng SS

This paper presents a number of mathematical models for predicting the different phases of the complete surface subsidence process associated with underground longwall mining. A computer program developed based on the mathematical models is briefly introduced.

Jan 1, 1992

By Gillies A. D S, Supriyadi

The landed cost of coal to the international customer is a major parameter which determines market competitiveness. Rail, port and shipping charges represent 30 to 50 per cent of landed costs for Australian mines selling to Asia. This prop

Jan 1, 1994

By Sinha NH

ICI Australia and CSIRO have developed a novel process for extraction of zirconia from zircon sands. The two stage process involves a high temperature step and a wet chemical processing step. A pilot plant has been operating since November 1985 at CSIRO Division of Mineral Chemistry, Port Melbourne and construction of a full scale plant isplanned at Kwinana, WA.The plant has a high degree of flexibility and is capable of producing high purity zirconia up to about 99.99% and withinspecific particle size ranges. The products are being marketed by the joint company, 2-TECH Pty Ltd.

Jan 1, 1986

By Floyd JM, Richardson P

The extension of theoretical and laboratory studies of the roasting of tantalite and cassiterite concentrates from Greenbushes Tin Limited to pilot and semi- commercial plant developments is detailed. A rotary pilot furnace was used to prove the feasibility of the process and a semi- commercial plant was constructed at Greenbushes to produce large quantities of roasted calcine. The additions and conditions of the laboratory study were employed to achieve marketable grades of calcine from the two materials. As well as producing calcines with less than 0.1% Sb, most of the tin in tantalite was recoverable to a separate fume product. Tin fumed during cassiterite roasting on a semi-commerical scale amounted to less than 1% of the tin in feed.

Jan 1, 1986

By King R. L

The Bureau of Mines has developed and deployed three expert systems to give advice on mining health and safety. These are: dust control for continuous miners, dust control for longwall shearers, and methane control. All three systems query about the nature and extent of the problem. Typical questions asked deal with observed methane levels, ventilation type and quantity, cutting sequence, and what control technology is employed. Advice given does not focus on a single issue, but may suggest a variety of approaches consistent with the ability of the operator to implement the Suggestions.

Jan 1, 1988

By Fulton E, Ring RJ, Waters DJ

The Nabarlek uranium treatment plant of Queensland Mines Limited (QML) is currently treating 600,000 tonnes of ore which was mined and stockpiled in a single four month period prior to commissioning of the plant. During the mining phase, material from the open pit was sorted into ore,'below ore grade uranium material (bogum) and waste using a truck discriminator (radiometric analyser) developed by Australian Mineral Development Laboratories (AMDEL). Ore was stockpiled in a single heap with the location and grade of each truck load being recorded. Bogum and waste were stored separately. From the information recorded, both computer and physical models of the stockpile were constructed. These models are currently used in the planning of day to day reclamation of ore from the stockpile.

Jan 1, 1984

This paper presents a summary of tools and methods used for geotechnical assessments and monitoring systems at block caving mines. A critical review of these tools is given based on the authorÆs experience in block caving operations. The reviewed tools include cavability prediction, fragmentation evaluation, geotechnical monitoring systems, numerical stress analysis and others. Some of these tools have been developed under certain circumstances in particular mines and experience shows that their applications under different geological and mining conditions have often been difficult. Examples from block cave mines are also utilised in this paper to illustrate the importance of the further development of these tools, whilst possible improvements on these tools are also suggested.

Jan 1, 2000

By Ju Hao L, Jian L

A joint project between the Fan Kou Mine, the Guangzhou Research Institute of Non-ferrous Metals, the Julius Kruttschnitt Mineral Research Centre, and the Changsha Design and Research Institute of Non-ferrous Metals has implemented grinding control on a circuit consisting of two primary mills and a single secondary mill at the Fan Kou mine in northern Guangdong province, PR China. This paper describes the initial design of the control system and the changes made during its implementation. The initial design was to obtain maximum throughput at a constant product size. This was changed so that the control provided a constant product density at a set feed rate. The set feed rate is reduced when necessary to prevent overloading of critical components in the circuit. The reasons for the changes in the control strategy are discussed.

Jan 1, 1993

Portable crushing at Duval Corporation's Sierrita open pit mine has proven both the economics and operability of large, hardrock, portable systems. In-house expertise was utilized to create a system incorporating both operational and maintenance features requested by operating personnel. The monitor/control system involves over 400 channels of information and is based on a DEC 1SI 11/2 microprocessor communicating with seven microprocessor-based data acquisition systems over a 4-wire, multidrop link. The year and one-half successful operation affirms the design philosophy and the hardware/software implementation.

Jan 1, 1985