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This paper presents the water management plan of the Mae Moh Project in the North of Thailand, which includes a large lignite opencast mine and thermal power plants. Lignite production will increase from the present 5.5 million tons per annum to approximately 20 million tons per annum by 1995 when the pit area will be about 20 sq.km. and the depth at over 300 meters. Seven power plants are proposed of which two are under construction. The total capacity to be installed is 2,925 MW. The principles considered for water management are firstly flood protection, including drainage of the mining pit and diversion of the Mae Moh stream away from proposed future mining areas; and secondly, a plan to meet the water requirement of the thermal power plants, while maintaining downstream supplies for irrigation and other purposes. The limited annual run-off of Mae Moh and Mae Chang watershed basins are inadequate for the proposed power plants. A study has been prepared to compare two approaches, namely conveying water from remote watersheds to meet the water requirement of the power plants up to total installed capacity; or by limiting future total generation, at the existing site, to only 2025 MV.

Jan 1, 1988

By G A. Davis, D G. Laughton

The great variability of mineral and energy prices has motivated some governments to incorporate a windfall profits tax into their mineral taxation regimes. Windfall profits taxes are a means for governments to capture additional mineral revenue when mineral prices are considered higher than some historic level. Governments need to be aware of the effects of such contingent taxes on the exploration, development and operating decisions of mining companies. Mining companies need to be able to calculate the full impact of windfall profits taxes on the economics of their projects. This paper examines the valuation of a multi-phase copper-gold project in the presence of a windfall profits tax. Real options Monte Carlo simulation is used to characterise the different exposures of the mine owner and of the government to the risky cash flow streams that they receive from the project. The results highlight that Monte Carlo simulation paired with the real option valuation method is able to account appropriately for the differing risk exposures, while the traditional discounted cash flow valuation model is not. Our key conclusion for governments and mining companies is that the impact of contingent tax and royalty terms can and should be assessed using advanced valuation techniques, and the results used to improve contract designs under the constraint of actual and perceived fiscal system stability.

Jan 1, 2007

CABS - Costs and Budget System - is being developed to provide more appropriate tools to assist cost control. The most important of these tools is responsibility accounting, that is to ensure the respons- ibility for costs and budgets is placed at the lowest possible managerial level in the Company. The system design and computer techniques utilized include the use of on-line facilities for enquiry purposes plus entry and validation of data. Data base management is used to permit the complex relationships that exist between data in CABS to be defined and maintained. The system must be flexible in order to cater for organisational and other maintenance changes with minimum time delays. The major outputs of the system are reports produced in several cost dissections, by responsibility, by products by cost collection group and type of expense. A significant role in CABS has been played by users. This includes development, control and review of the system proposals in order to ensure that the objectives and requirements from all sections in the Company are met. This role has included Project Leader for the system plus a committee formed to provide formal acceptance of the system Design.

Jan 1, 1977

Although giant strides have been made in the Australian mineral industry over the past quarter of a century in terms of mineral discoveries, self-sufficiency of commodities, contributions to exports and other aspects, there are unhealthy signs emerging which require attention. For instance there are 20 out of 34 discoveries of base metals, uranium and nickel which for a number of reasons await development. Some of the reasons for the standstill in the mineral industry are partly economic, partly due to competing land use, uncertainty in applying or, recognising the principle of crown ownership of minerals, and to some extent lack of appreciation of two closely related exploration activities referred to as development exploration and assessment Exploration.

Jan 1, 1979

By E A. Agorhom, P N. Aabulleh

The bulk of the worldÆs production of iron ore is processed into steel. The needs of the steel industry therefore demand a high exploration and exploitation of iron ore. One trend within the industry has been a great increase in the demand of iron ore and this is reflected in an increase in world steel production from 1955 to date. In addition to the high demand for steel, is ChinaÆs high appetite to feed its steel industry. It is therefore important that the iron ore potential of Ghana is showcased for eventual exploitation by potential investors to meet this enormous demand for the commodity in the industry globally. Ghana has three main iron deposits of potential industrial and commercial importance. They are: Shieni sedimentary iron ore (reserves: 1.270 X 106 metric tonnes), Pudo titaniferous-magnetiferous iron ore and the Opon-Mansi lateritic iron ore deposits. The Opon-Mansi iron ore deposit occurs in the Western region of Ghana. The ore deposits are located on top of the range of 15 hills, which extend over a distance of 24 km from Opon-valley, south of the Western region to Dunkwa. The area has an estimated 147 Mt of iron deposit, with Fe content of 52.5 per cent. This paper looks at the iron ore potential of Ghana and how it is capable of attracting potential investors to exploit this valuable mineral for global consumption.

Jan 1, 2007

By Walter GW

Rock mass classification systems for stable excavation design have been studied. The parameters which are important in such a classification system and those which should be included in a classification system formulated to predict explosive fragmentation behaviour are briefly reviewed and compared. There is significant overlap in the data requirements for excavation design and explosive blast de- sign. Recently there has been a trend to ob- tain some of the data required for excavation design by the use of both field and laboratory seismic investigations. The theory of seismic techniques is summarised and the results of seismic investigations carried out for excava- tion design are reviewed. On this basis it is considered that seismic techniques have the potential to be used for data collection prior to blast design. A programme designed to de- velop such techniques and which includes both field and laboratory experimentation is Presented.

Jan 1, 1978

By Sheridan GD

Fifteen samples 'of clays and shales from the Adelaide area were selected from a total of 84 as representing material of possible value for the manufacture of light-weight aggregate. A detailed examination of the bloating. characteristics of these revealed four likely to be suitable. for expansion.' in a rotary kiln. One of these, a Tapley. Hill shale., was-fired in an 8 in. diameter rotary kiln, but con-tinuous bloating without ring formation in the kiln was not achieved. Steam,,-oxygen,, sulphur dioxide and carbon dioxide have been, suggested. as the agents of bloating. An examina-tion of .. the evidence : `leads to the conclusion that carbon dioxide derived from. carbonate minerals is likely to be the principal bloating agent. Attempts to bloat clays by the addition of mica were.not successful.

Jan 1, 1963

By N Boughen, P Ashworth, S Johns, C J. Yeats, A Littleboy

The ocean floor, often called the last frontier, is increasingly discussed in terms of its resource potential û from near shore building aggregate and placer deposits to massive sulfide orebodies in the deeper ocean. Consequently there is an increasing incentive to mine the seafloor. But, do we have the social license to explore and mine the seafloor? Does this nascent industry have support amongst the wider community? If not, why not? And what should be done? To answer some of these questions, the Wealth from Oceans National Research Flagship has explored the social viability of an expanded seafloor exploration and mining (SEM) industry inAustralia. The results show that there are significant geological and environmental data gaps and that, in the absence of sufficient information, stakeholder reaction to the prospect of an SEM industry expansion may be reactionary and negative. This uncertainty means that the perception of risk from the industry is variable and often dependent on individual values. The acceptability of an expansion to the SEM industry is currently precarious, in particular due to the high levels of uncertainty regarding the environmental impacts of seafloor activity. While there are existing federal regulatory frameworks and government processes for the licensing of seafloor mineral exploration and extraction, there is little precedent in the application and implementation of these regulations. The future viability of the industry will be highly dependant on AustraliaÆs ability to improve the knowledge-base underpinning its regulatory regime and also to generate open and transparent communication channels between stakeholders. It will also be dependent on the SEM industryÆs ability to communicate an acceptable value proposition to society. This proposition will need to include the relative impacts of terrestrial and marine mining, the alternative potential uses of the ocean and the multi-use conflict that SEM might engender. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By P M. Downes

Porphyry-related skarns are common around thePacific Rim. Examples include Cadia and Goonumbla (Australia) Ok Tedi (PNG) and Ertsberg and Grasberg (Indonesia). Although usually treated as separate to the adjacent porphyry copper-gold (Cu-Au) deposit, skarns near porphyry deposits are commonly inextricably part of the larger Cu-Au system(s). Using Cadia as the primary example, we demonstrate that large, zoned, calc-silicate skarns necessitate very large porphyry systems. The Big Cadia and Little Cadia Fe-Cu-Au skarns are associated with the Late Ordovician to Early Silurian high-K calc-alkaline to shoshonitic Cadia Intrusive Complex (CIC). Together, these skarns total ~40 Mt of Cu-Au ore but are much smaller than the adjacent Cadia EastûFar East, Cadia Hill, and Ridgeway porphyry-related Cu-Au deposits. Historically these skarns were large, economically significant and highly controversial deposits. Porphyry-related skarns typically have well-developed calc-silicate and ore zonation. At Cadia, classic skarn zonation has been mapped between Cadia Quarry (proximal) and Big Cadia (distal). Over this 800 minterval, mineralogy trends from: proximal garnet > pyroxene, grading to; fe-oxide-rich skarn; and distal haematite-epidote-rich skarn. At Little Cadia, analogous but symmetrical alteration zonation is present. Big Cadia formed from fluids that migrated laterally within calcareous units and were sourced from strongly altered quartz monzonite phases of the CIC at Cadia Quarry. Isotope studies and mass-balance calculations suggest that prograde and retrograde skarn alteration was caused by magmatic dominated fluids. They also indicate that the mapped alteration system at Cadia Quarry is insufficient to account for the total volume of Fe present at Big Cadia. Despite the typically oxidised nature of many porphyry systems, not all skarns in the porphyry environment are oxidised. Assimilation of carbonaceous sediment by hydrous, alkaline intrusions could lead to reduced Au skarns rather than porphyry deposits. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By D Landriault, G W. Wilson, L Langetine and

Engineered soil covers are used for final closure options for both waste rock and tailings disposal facilities. Currently, cover construction requires excavation of appropriate cover material from a nearby site. If no suitable materials are available, the mine operation may have to ship appropriate materials long distances to the site before the construction of the cover can even begin. This has led to the proposal to engineer cover materials using existing waste materials from the mining operation. The paper presented here describes the results of a laboratory scale testing program to evaluate the potential for blending waste rock, smelter slag and tailings for the creation of a suitable cover material at a site in Canada. Tailings from the local mill, waste rock and slag were collected in the field and blended to create a material with an air entry value similar to the tailings and with physical strength similar to the waste rock. Testing indicated this mixed material could be blended at a consistency of a paste and was suitable for pumping. It can also be compacted to a high-density material. The preliminary results show that it may be possible to blend waste rock, slag and tailings into a material that can be utilised in the construction of a water retaining cover.

Jan 1, 2003

By Stevens LG, Mok JK

With the long lead time requirement for engineering and construction of mineral pro- cessing facilities and the costly financing arrangements necessary, effective project management is essential to the successful and timely start up of these major production units. An added complexity is the frequently remote location of such projects and the demands this imposes on efficient project staffing, scheduling, logistics and cost control. Parsons recent experience with major projects such as Greenvale in Queensland and La Caridad in the desert of Northern Mexico and at remote locations like Sar Cheshmeh in Iran are described. The applications being developed for improving project controls through the use of computer techniques such as MSCS-COPES, and readily accessible and versatile transportation means are reviewed.

Jan 1, 1981

X-ray analysis of polycrystalline powder samples has grown beyond its roots in the world of laboratory research and is now regarded as one of the most powerful industrial process-control tools in the field of building materials. This is the key to characterise the element and crystalline phase composition of the material. This is due largely to the development of industrial X-ray analytical systems such as PANalyticalÆs twin solution, which has transformed the advanced analytical techniques born in the laboratory into a robust, workmanlike and easy-to-use tool for todayÆs heavy industries. The increasing use of alternative fuels makes the Bogue method less reliable. Therefore, the real phase quantification by the Rietveld method is the only choice. Additional fine-tuning of the Rietveld method by using alternative methods guarantees the most accurate quantitative results. Moreover, the recent development of ultra high-speed X-ray detectors allows for æon the flyÆ quantitative X-ray diffraction analysis and a truly interactive process and quality control.

Jan 1, 2008

By R West

The Olympic Dam smelter facility processes copper concentrate feed using direct-to-blister smelting technology to support the current site production rate of 225 000 t/a copper. The metallurgical control of the Olympic Dam smelter is largely managed from a single central control room. Control room operation and management is therefore a key function in ensuring safe and reliable operation of the smelter, including identifying and initiating control of abnormal events. As part of a consolidated smelter reliability improvement program, a team consisting of process and control system engineers was formed. The teamÆs charter was to address and resolve the alarm flooding issues being faced by the control room technicians and the lack of an up-to-date base of supporting functional documentation. The project was successfully resourced with WorleyParsons metallurgists, Citect PLC technicians and the on-site technical team. Implementation was conducted over a 12 month period with the goal of achieving best practice alarm levels. The goal was achieved through a systematic process of alarm design review that analysed every configured alarm versus best practice design standards. Innovative concepts such as group-based alarms, first-up interlock displays, graphic only alarming, alarm help and alarm shelving were developed and implemented in conjunction with improved alarm masking. Total configured alarms were reduced from 20 000 to 5000 while the alarm rates were reduced from in excess of 200 alarms per hour per controlling technician to best practice levels of less than 12 alarms per hour per controlling technician. Completion of this program has provided a firm foundation for implementing further control optimisation and was a key activity in supporting sustained smelter reliability levels.

Jan 1, 2005

Experience in evaluating grade control at operating mines has shown that a number of similar errors re-occur in diverse settings. These can be broadly classed as technical errors, and procedural or grade contra management errors. Examples of typical errors are presented a; generalised case studies. A brief explanation of why the recommender solution worked is also presented for each case.

Jan 1, 1993

Ore petrology will fundamentally determine the types of metallurgical processes employed for ore treatment, their operational efficiency and the nature of processing problems encountered. It is therefore paramount that the petrological charact

Jan 1, 1998

A novel solvent extraction process, called the SOHNEX process, has been developed at the University of Utah. In this process, the organic and the aqueous phases flow countercurrently in a horizontal vessel, and the emulsion between the two liquid phases is generated by high-velocity gas jets injected at the bottom. The gas jets are located at certain intervals along the bottom of the vessel with phase disengagement zones on either side of the plume zone created by the gas jet. The system is simple, having no mechanical moving parts or complex internal structures, and yet provides good contact between the phases with minimal backmixing. Tests have shown that emulsions with a wide range of specific interfacial area, including that typically encountered in mixer-settlers, can be generated in this process. It has significant built-in flexibility of operation including the control of the flowrate and hold-up of each liquid phase. The SOHNEX process overcomes the difficulties in the operation of conventional solvent extraction equipment such as mixer-settlers and column extractors. A major advantage of the SOHNEX process is that the energy of mixing can be closely controlled by adjusting the strength of the gas jet. This allows an optimal control of the drop-size distribution of the dispersed phase and thus the specific interfacial area. The process is continuous, and any number of extraction and separation stages may be built into a single vessel. The gas can be recirculated in a closed loop, thus eliminating solvent loss and mist problems, especially for high-temperature operations. The SOHNEX problem can handle solutions that contain suspended solids and that form third phases. The simplicity of the equipment and operation with low maintenance will mean much reduced capital and operating costs as well as low environmental risks and improved safety. The SOHNEX process has been tested for continuous copper extraction from a dilute solution. Calculations also showed that uranium and other radioactive elements can readily be extracted in a small unit of the SOHNEX extractor while satisfying the nuclear criticality condition.

Jan 1, 2000

By Fraser C. J

The township of Yalloum was established in 1921 to provide accommodation for the work force on the sites of the power station and open cut which were to become the basis of Victoria's electricity industry.A company town, Yallourn flourished, and in its heyday in the 1950s the township had a population in excess of 5500 residents.However the town was sited over a valuable coal field. In the 1960s, studies conducted by the State Electricity Commission indicated that excavation of this coal as a continuing development of Yalloum Open Cut was the optimum choice to meet the growing energy needs of Victoria. Operation in what became known as the Township Field commenced in 1979 and the completion of the overburden stripping was successfully achieved on target in 1991.

Jan 1, 1992

The short review of hydrogeologic conditions in the three Polish coal basins have been presented as the background for the prevention measures against water inrushes being underta- ken in coal mines. The Polish mine safety regulations concerning water inrush prevention have been discussed, namely: - classification of sources of the potential water inrushes, - levels of water inrush risk and conditions of mining operation in the mines facing particular risk levels, - determination of the -di.mens.ons.of protecting pillars to prevent water inrush to mines, protection of surface water reservoirs and their earth embankments in regions submitted to mining deformations. Three examples of coal mining being carried out under water bodies have been presented.

Jan 1, 1988

Progress on this project will be verbally reported and a description given of the main features. A detailed feasibility study was completed in December 1986, and the Joint Venture has issued an Environmental Impact Statement. This was open for public comment until 16 February. Issues presently being considered include economic justification traffic, air quality, noise, marine fauna and flora, visual impact, heritage and construction impact. Detail design and construction is likely to commence in mid 1987, following determination of the above matters.

Jan 1, 1987

Open pit planning and scheduling play a significant role in establishing, maintaining and improving the economics of open pit mining ventures.The development of an open pit plan and schedule involves consideration of the following elements:ò the market for the mineral, ò the mineral deposit,ò the treatment process, ò the external factors,ò the mining method,ò the scale of operations, ò the open pit design,ò the open pit schedule,ò the calculation of economic performance, andò the implementation of the open pit plan and schedule.The above factors are described and discussed. Open pit planning and scheduling is the linkage which enables a mineral deposit amenable to open pit mining to meet a market requirement for the particular mineral. To effect this linkage the open pit planner should have a good detailed appreciation of both the mineral deposit and the market.

Jan 1, 1992