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Most Geologists have a well rounded knowledge of the exploration phase and those who have worked as mine geologists have an understanding of the production phase. Few have had exposure to the development and the construction phases. Even fewer have had the experience of closing a mine, disposing of the plant and equipment, carrying out the final cleanup and making the area safe and environmentally acceptable.During the various phases of exploration, the geoscientist gains a wealth of non-geological information which can be of considerable value to engineers and technicians in the feasibili-ty, development, operation phases and finally the closure of a project. Such basic controls as surveys, adopted assay sample lengths and the location of items of infrastructure during exploration, may continue to affect the project through its entire life. Thus the geologist's responsibilities extend well beyond the explo-ration phase of a project.

Jan 1, 1990

North Stradbroke Island is a large sand mass offshore from south east Queensland. Dredging for mineral sands commenced there in 1956 and the rehabilitation discussed in this paper was commenced in 1967. The frontal dunes have a long history of instability, with little vegetation prior to mining. Re-establishment of the naturally stable contours is essential, and their rehab- ilitation is described. Vegetated high dunes present different problems requiring attention to regeneration of the native species. Methods developed over the past eight years are proving successful.,

Jan 1, 1976

By M M. Tarshan

Separator performance is evaluated by the so-called separation efficiency. The concept of efficiency in mineral dressing operations must be interpreted with considerable care. Although qualitative use of term efficiency is valid and useful, difficulties arise in expressing it quantitatively because two conflicting criteria, grade and recovery are normally involved in its evaluation. It is undesirable to express efficiency as a single value, even though this is frequently done in practice, since there are strictly speaking an infinite number of combinations of grade and recovery that can give that one value. Inefficiencies in processes can be attributed to three broad sources: mineral limitations as represented by the separability curves, equipment limitations (which prevent the maximum separation indicated by the separability curves), and human failure to minimise these inefficiencies. In the present paper, the efficiency of a two-constituent separation process has been examined. The separation process has been evaluated by comparing the sharpness factor of the actual, the absolutely efficient and the absolutely inefficient operations.

Jan 1, 2000

By E Hogan, M Goodz, R Wright

The planning, permitting and monitoring procedures of the re-opening and rehabilitation of mine sites is an ongoing process which must continue throughout and beyond the life of the project. Both industry and government bodies must remain flexible to allow guidelines to be altered where and when necessary.To enable the successful re-opening of the Morning Star mine at Woods Point in alpine Victoria, many environmental and historical issues had to be evaluated.The site which had been derelict for 28 years had to be rehabilitated to a safe and aesthetically pleasing state prior to construction of a new operating mine site. Considerable liaison with government authorities and the local community was required.

Jan 1, 1992

By Budd B

this paper outlines the operating advantages gained through applying a mine processor (MISA), to various underground and surface operations. On the surface, MISA monitors and/or controls ventilation fans, crushers, fill plant and stockpiles. Underground, MISA monitors and/or controls dewatering pumps, fill reticulation and high voltage electrical distribution on most levels.

Jan 1, 1988

Natural gas was introduced to the Melbourne reticulation system in April 1969 and since that date sales to industrial consumers in the Gas & Fuel Corporation of Victoria area of supply, have increased by over 50% This increase has occurred despite the fact that the areas in which the new fuel is available have been dependent on the progress of the conversion operation from manufactured gas. The half way mark for conversion was reached in May 1970. The reason for the adoption of natural gas by industrial users is usually the result of objective financial analysis leading to the conclusion that the new fuel will give the lowest overall production cost. Many factors are involved in such an analysis of which the price of the fuel is only one. Amongst other important elements in the cost calculation are:- -ò òò -(1) The effect of fuel on product quality (2) Maintenance and handling costs for alternative fuel. In addition to economic gains for the individual user, the use of natural gas should benefit the whole community through its effect on such things as, air pollution and overseas balance of payments.

Jan 1, 1970

By P Hucker, E Hall

Harmony Gold operates the Mount Marion underground gold mine near Kalgoorlie, Western Australia. The mine consists of two ore zones, East and West, and mining of these zones is currently conducted using the sublevel caving method. When mining commenced in the Western zone, the span was insufficient to induce caving of the country rock above. Dyno Nobel, together with Harmony and 360 Drilling, developed an innovative drill and blast solution in order to promote cave propagation and improve the safety of personnel at the operation. The solution involved a series of shallow angle drill holes up to 90 m into the hanging wall of the West zone. These were charged with Titan« 7000 underground bulk emulsion and the HotShotÖ electronic initiation system. The blast used over seven tonnes of emulsion and 46 detonators and achieved the desired result without damaging nearby mine infrastructure.

Jan 1, 2007

ICI Australia has been developing PC-based software to assist the blast engineer to design and monitor open pit blasts. The scope of this software differs significantly from commercially available mine design packages.The software is designed for routine use in a normal production environment. The system enables the engineer to produce practical documents which include: a drilling plan, a loading sheet, a hook-up diagram, an inventory of explosives and auxiliary items, and other data on the blast such as tonnages and powder factors.

Jan 1, 1992

Optimising a mining or a quarrying operation about the overall cost is quite a challenge as there never is a situation where we have exactly the same conditions regarding rock properties, explosives' performance, mining equipment or evironmental restrictions. The amount of endless influencing parameters and variables make the evaluation process difficult. The enormous progress we have seen during the recent two decades in computing has however significantly increased our ability to evaluate and process the information gathered, and refine our existing prediction models. Refined models demand an increasing volume of good quality information to show reliable conformity with reality. There is a great need for co-operative work in the mining and quarrying society if we shall be able to screen all available data, systematically find the key-parameters influencing the results and to build robust scientific models. No organisations today have all the skilled people needed or can afford to hire the necessary specialists in all the overlapping branches. This paper highlights some on-going work where the Dyno Explosives Group is adding some new pieces to the giant jigsaw puzzle representing the ultimate model of the mining and quarrying operations we all of this society would like to see completed.

Jan 1, 1995

By E J. Gardiner, C M. Hogan

Acidic drainage has long been recognised as the largest environmental liability facing the mining industry, and to a lesser extent, the public, through abandoned mines. The Canadian Mine Environment Neutral Drainage (MEND) initiative was the first international multi-stakeholder program to develop scientifically based technologies to reduce the effect of acidic drainage. The original MEND Program extended over a nine-year time frame ending in 1997, with technology transfer activities continuing to the end of year 2000 under the MEND 2000 program. Both programs have contributed enormously to the understanding of acidic drainage and how to prevent it. MEND3, launched in 2001, intends to further this effort with a strong, research-driven program. The successes of the MEND initiative have come through the collaborative efforts of the partners, the sharing of experiences, the thorough evaluation of technologies and their incremental improvements. As a result, the knowledge base on acidic drainage has grown considerably. An international model of alliance between the various worldwide initiative involved in acidic drainage is being formalised at this conference. This global alliance will enhance technology transfer capabilities and will lead to improved environmental performance for the industry. It is through collaboration that we have achieved the most progress in environmental performance, and this formal relationship will further expand these benefits.

Jan 1, 2003

Accounting for borehole damage in analytical modelling of explosively generated stress waves is important for predicting the finer details of the stress wave patterns observed in the field. The classical Sharpe's [19421 concept of an effective borehole larger than the initial borehole diameter has been widely accepted to explain material damage around a borehole. A new analytical model based on dynamic compaction is advanced to predict far-field stress wave patterns. This model supports field data corresponding to reduced frequency of oscillations and increased damping. The present model recovers the earlier result when compaction around the borehole representing borehole damage is ignored.

Jan 1, 1990

Project managers must juggle many aspects to bring their project in on time, on budget, and in accordance with the aims of the project owner. Whether the project is a mining feasibility study, a technology implementation or a construction project, it falls to the project manager and his or her team to deal with risk from two standpoints, which may be at odds with one another. First, a project team must deal with risks to the project itself û that is, risks to on-time, on-spec and on-budget delivery against the value promise made to the customer. Second, there is the management of risks within the subject matter of the project, undertaken on behalf of the customer. The project manager cannot dodge this responsibility; yet there is a tendency (particularly in smaller, in-house studies) to avoid digging too deep, possibly for fear of what may be uncovered! This paper investigates the responsibilities of project teams in regard to risk management and reporting. It examines ownership of project risk; the nature of risk management activities undertaken by the team during the course of a project; and outlines some controls to ensure that the two opposing arms of project risk are reconciled for the benefit of both the project team and the project owner.

Jan 1, 2007

This paper compares and evaluates the impact of income tax and value-added tax on the decision to explore for minerals or to develop a mine in four countries: Australia, Papua New Guinea, Argentina and Indonesia. Three aspects are considered in depth:- domestic tax rules applicable to mining projects;- taxation of foreign mining investment and foreign providers of expertise;- taxation of project finance (other than equity) from foreign sources.Specific tax issues discussed include tax deductibility of various costs, treatment of tax losses, special tax incentives, comparative treatment of various corporate structures, non-resident withholding taxes, and tax costs of various forms of project finance. The paper also illustrates the comparative impact of income tax on rates of return by means of a simulation of a mining project in each of the four countries. The simulation demonstrates why the highest rate of return may be obtained in Argentina and the lowest in Australia.Relevant features of the income tax systems in each country (at 15 February 1990) are summarized and compared in several tables annexed to the naner.

Jan 1, 1990

The crushing and concentration of ores, as Herbert Hoover commented in a footnote in De Re Metallica, stretches back at least 6000 years. During those years there have been continuing changes and improvements in mineral processing technology. It has expanded greatly in its ability to handle different types of minerals, and lower grade and more complex ores. Australia will be dependent on the mineral industry for the fore- seeable future and there will be continuing demands on the mill opera- tors to improve the technology with regard to efficiency, flexibility and costs. These demands will be met successfully in the future as they have been in the past. This Mill Operators' Conference is an important forum for assessing our present position and planning for the future.

Jan 1, 1988

FIRST TOWN PLANNING PROPOSALS Initially, accommodation at the minesite was provided at the Pastoral Homestead situated some seven kilometres north-east of the mine and between 1963 and 1966 was the base of the exploration camp. Tents were used for sleeping of 100 men and the Homestead used for dining and office facilities. With the beginning of ore production and shipment due to commence in 1969 a permanent town location was sought. Early town planning studies had been commissioned by Amax Inc. and Colonial Sugar Refining Co. Ltd. and in 1967 The Broken Hill Proprietary Company Ltd. took over the responsibility for putting them into effect. The location chosen was about four kilometres due east of the mine. Certain dominant factors influenced this choice. It was near enough to the mine to share services, yet far enough away not to be affected by dust and noise and received the additional shelter of a range of hills separating it from the mine. A predominant slope to the east provided good drainage and the ground was easy to excavate for services.

Jan 1, 1976

The beneficiation of heavy metal oxides, such as iron ore, is usually performed with heavy medium separation in cyclones, static baths and lately with Larcodems. Atomized ferrosilicon is most suitable as a heavy medium at densities above 3600 kg/m3 whereas a mixture of milled and atomized ferrosilicon is suitable at densities below 3600 kg/m3. When operating a beneficiation plant at densities higher than 3600 kg/m3 the quality of the ferrosilicon particles is an important factor that influences the control of the beneficiation process. Therefore, it is important to know how the rheology would be affected by the ferrosilicon quality as it also influences the control of the process at these elevated densities.

Jan 1, 2002

By M Magee, D Way

The Mount Isa Copper Concentrator was commissioned in 1973. In 1991, two autogenous grinding mills were installed replacing two stages of crushing, one stage of rod milling and one stage of primary ball milling. The cyclone overflow P80 of the secondary ball milling circuit was reduced to 120 microns due to the increased operating power in the AG/SAG mill circuits. A study of the mineralogy of the milled products and the plant flotation recovery indicated that the installed secondary grinding energy was more than what was required for adequate liberation of the chalcopyrite and half of it had potential for more effective use elsewhere. Halving the secondary grinding energy meant only one of the two secondary ball mills would be needed. The predicted saving in operating cost of one less ball mill was more than two million dollars per annum. This paper summarises various plant trials that were conducted in the Copper Concentrator to decommission one of the two secondary ball mills.

Jan 1, 2004

By Gregg PEH, Horne D, Bolan N, Stewart RB

The Tui mine site is situated on the NW flank of Mt. Te Aroha, at approximately 400 m altitude. During underground mining operations two lead-copper-zinc ore bodies were exploited and processed on site. The legacy of the mining operation is a barren dam containing over 100,000 m3 of sulphide-rich tailings. The Tui mine site is arguably the worst case of environmental degradation resulting from past mining activity in New Zealand. Although the impacted area (approximately 4 ha) is extremely small by international standards, acid mine drainage (AMD) emanating from the abandoned tailings dam and mine adits has severely contaminated local streams and prevented natural plant recolonisation of the site for more than 20 years.

Jan 1, 1995

While South Africa is well endowed with mineral resources, it is generally accepted that its future will be determined more by the development of its human resources than its mineral wealth. The country has throughout its modern history suffered from an over-supply of unskilled labour and a shortage of skilled and professional manpower. There has furthermore always been an over-reliance on Whites as an internal source of professional manpower, supplemented by immigration wherever possible. Better utilisation of other population groups in professional positions has been hampered by the general lack of education and training among such groups. Although many problems still remain, there are emerging trends which are likely to positively affect the training of professional manpower in the future. The direct and indirect influences that are likely to affect professional training at the macro level include 1. government policy and objectives in respect of manpower education and training, 2. the emergence of technikons as fully- fledged tertiary education institutions, 3. demographic trends in South Africa as they pertain to education, 4. political and statutory developments in the country, 5. industry involvement in tertiary education, and 6. professional registration.

Jan 1, 1986

During the development of Lorca tunnel project in the South-East of Spain, an in-site study has been done, with the purpose of obtaining the characteristics of the different lithological units through twenty-two parameters for the design of the tunnel excavation and support. In the paper both the different works developed and the different methods and criteria followed in the obtention of the parameters are described. The values of those parameters may be useful in similar cases. Also a summary-table of the parametrical characterization for the use in similar studies is given.

Jan 1, 1987