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By Jones BH

Discovery of the Vera-Nancy deposit in late-1995 followed 12 years of active exploration in and around the Pajingo Epithermal System, an andesite hosted veinfield covering an area of 150 square kilometres at the northern end of the Devono-Carboniferous Drummond Basin in North Queensland. Early exploration targeted open-pittable resources in the numerous auriferous veins and it was not until 1994 that exploration focus shifted to drilling to depths below about 100 metres from surface, which resulted in the Vera-Nancy discovery. That deeper drilling process is still at a very early stage of coverage of the epithermal system as a whole and substantial potential exists for additional discoveries.Drill-out of Vera-Nancy has to-date established a gold resource in excess of 1.4 million ounces. Mine development is proceeding via a twin decline system with first stoped production scheduled for August 1997.

Jan 1, 1997

The company was formed in 1926 to exploit tin bearing veins adjacent to Aberfoyle Creek in north-east Tasmania. In 1928 a 923ft tunnel was driven to explore and develop the mine 150ft below surface. This put the company on a path to become Australia's second largest tin producer by the late 1960's. Recently, Aberfoyle Resources Limited completed a 1.1km tunnel to access the major Hellyer zinc, silver, lead orebody at 300m depth. Production at 1 million tonnes a year is likely, and will make the company a significant world supplier of zinc by the late 1980's. The intervening 20 year history of survival and diversification illustrates principles of mineral exploration which proved valid in the Australian context. The objective of exploration should be to develop mines which can survive rigorous competition and downturns in commodity prices. Such mines will be based on orebodies with many of the following characteristics described by Richards (1986).

Jan 1, 1987

By A Nixon

The Australian mining industry has changed dramatically over the past 20 years in terms of mining methods, mining equipment and human resource policies. The industryÆs approach to safety and health in terms of attitudes, style of legislation, and risk management techniques has also changed significantly. These changes have had and continue to have major impacts on the design of underground mine ventilation systems. In some areas, trends are clearly emerging. In other areas, mine ventilation planning remains very æreactiveÆ and is performing poorly in terms of providing a safe and healthy work environment at a reasonable cost. New concepts involving the role of ramps and shafts, the provision of refrigerated air, æventilation on demandÆ and newe gress and entrapment approaches are likely to be incorporated into mine planning and operating practices over the next ten years. This paper discusses these and other trends and identifies some likely future developments in the area of hardrock mine ventilation.

Jan 1, 2005

By Lynch A. J

The success of the Australian mining industry depends on the quality of its skills. High quality skills supported by a culture which demands success lead to innovations, good practices and prosperity. Average skills lead inevitably to mediocrity. Universities play an essential role in the development and use of skills but the crucial industry-university links have been subordinated to conventional academic interests in training mining and processing engineers. It is only in the area of post-graduate research degrees which are oriented towards the mineral industry that Australia can claim world leadership. Deficiencies are not due to lack of training resources, they are due to inadequate utilisation of the resources that are available. Australia can and should have the world's best mineral engineering school, with a branch in Asia where many of its customers are and close ties with South America where some of its production operations will be. Some steps which might be taken to achieve this are proposed.

Jan 1, 1995

By E S. Bernard

Steel fibre reinforced shotcrete (SFRS) is increasingly being used as ground support in both civil and mining applications. In recent years, methods of assessing the performance of SFRS have been developed. These include the beam test such as that prescribed by ASTM C-1018 and the panel test prescribed in the EFNARC European Shotcreting Standard. The panel test has gained popularity in recent times due to the two-way action modelled in the test. However, some difficulties have been noticed. Shear failures sometimes occur and there appears to be a rather high degree of variability in the panel test results. A new method of testing panels has been proposed. A circular panel supported on three symmetrically arranged points has been assessed at the University of Western Sydney. This paper describes the new test which may be the basis of a new specification for the testing of toughness of SFRS and summarises research work which has been carried out to-date.

Jan 1, 1999

By Ruffles B. R

A computer simulation has been developed to model the flow of copper ore in Isa Mine. It simulates extraction of copper ore from the 1100 orebody by load-haul-dump (LHD) units to ore passes, haulage from chutes on 19 level by Rockflo trains to crusher bins, crushing and hoisting. It can assess in terms of the tonnage and head grade of ore hoisted, the effect of varying operating strategies, as well as measur- ing shortfalls in required capacities of any of the operations (extraction, hauling, crushing and hoisting). The simulation was designed as a modular, deterministic, steady-state model with parameter input allowing complete flexibility in its use. Queuing theory is used extensively to evaluate the effect of interference at potential bottlenecks. The model has been used to determine the effect on production of varying train sizes, maintenance policies on the haulage circuit, orepass capacities, and extraction operations.

Jan 1, 1974

Extensive geophysical exploration and drilling operations have been: conducted in, South Central Queensland by Phillips Petroleum Company and Sunray DX Oil Company since late 1959. The main outlines of subsurface geology are now known, but many problems must be solved before a comprehen sine. picture can be presented of the geology and petroleum prospects e Interpretations to date suggest that -fiddle Paleozoic sedimentary rocks, probably, related to the Tasman belt of geosynclines, once extended. over. most. of the area An oro;eny 2.n late Paleozoic time, succeeded by deep pre-Pexmian erosion, removed the older sediments over large. areas, but Paleozoic sediments, were preserved from erosion in the Adavale and ancillary structur-a.l basins. Marine sediments of Devonian age are con-sidered prospective source beds for petroleum. Current work is directed toward finding favorable structure and reservoir beds to test the oil prospects of the area.

Jan 1, 1962

With the continued drop in export coal prices (as measured in US$) delivered to the Pacific Rim market, and a fixed annual 12 per cent increase in overburden, Usibelli Coal Mine Inc was faced with the need to reduce mining costs substantially or else forfeit its foreign coal contractual commitment which amounted to about half of annual mine output. Management made a difficult and fortuitous decision to proceed with an engineered plan to switch from a two seam, extended bench dragline operation to a two seam, cast blast and spoil side operation. While down-sizing and cut-backs became the rule in all departments of the mine, the drilling and blasting budget was more than doubled. Most will agree that this is contrary to what usually happens when a mine is faced with down sizing. The more common scenario would have management target the drilling and blasting budget for decrease as a first priority to cutting cost, and then later witness a decrease in equipment performance leading to an increase in the production cost per tonne. Although Usibelli Coal Mine more than doubled its annual drilling an blasting budget three years ago, the overall stripping cost has be, reduced by more then 37 per cent.

Jan 1, 1995

The paper gives details of the reasons why attention was directed towards the modification of flotation cells. The cell volume and impeller speeds were reduced, and it is estimated that the power consumption for lead and zinc flotation will be reduced by about 2·8 kWh per ton of ore treated, and that substantial savings will be made in maintenance costs. The metallurgical efficien.cy of the operation has been maintained and attention is now being directed towards the improvement of grades of concentrates and recoveries of metals.INTRODUCTIONIt was on 1st August, 1934, that the first Denver No. 21 flotation cells were operated in the treatment plant of The Zinc Corporation Limited, in a pilot Nant which had been installed to determine the economics of all-flotation as against the then existing gravity and flotation practice.The ore being mined at that time came from the lead lode which consists of a granular mixture of galena, marmatite, chalcopyrite, tetrahedrite, pyrrhotite, pyrite and lollingite with a gangue association of calcite, quartz, bustamite, rhodonite, manganhedenbergite, garnet, fluorite, manganocalcite and apatite. The silver content of the ore occurs in three minerals-tetrahedrite, dyscrasite and pyrargyrite, the last two mentioned occurring in microscopic association only.A parallel lode, known as the zinc lode, was well developed at that time. The common lead lode gangue minerals-calcite, rhodonite, bustamite-were rare in the underground exposures of the zinc lode. No metallurgical work was done on this ore during the pilot plant operations although since then both lead and zinc lode ore have been treated.Early in 1936 plans were made for the complete re-organization of the mine operations, and in view of the metal-

Jan 1, 1956

Classifications of Ni-Cu deposits are based on petrology, geochemistry and the geotectonic setting of host igneous bodies (Naldrett and Cabri, 1976; Besson et al, 1979; Nadrett, 1989). The four major classes in Naldrett's (1989) division rest on the geotectonic setting of the igneous complexes and the classes are further subdivided on the basis of the petrology and geochemistry of the intrusion. A more common subdivision of mafic and ultramafic igneous rocks is based on the environment of rock-forming processes, endogenic or exogenic, intrusive or extrusive, and this subdivision has been applied, in practice, to the classification of sulphide Ni-Cu deposits, too. The extrusive deposits, Class I in Naldrett's (1989) classification, are directly related to volcanic processes whereas all the others refer to the intrusive environment. This paper looks at the differences between the extrusive and intrusive groups of Ni-Cu deposits and presents generic, genetic and structural features of the intrusive group.

Jan 1, 1996

Although laterite ores already provide a significant proportion of the world's nickel and cobalt production it is anticipated that they will surpass sulphide ores as a source of nickel in the next century. The most recent period of greenfield nickel project construction was during the 1970s when it was notable that all of the eight new plants were based on treating laterite ores. This was because of the relatively large selection of available high grade laterite ore deposits amenable to cheap open cast mining and a paucity of high grade sulphide ore prospect alternatives. Of the three processing options for treating laterite ores: 1. smelting for the lower horizon saprolite ore, 2. ammonia; and 3. acid leach for the upper horizon limonite ore, smelting currently accounts for about 80 per cent of nickel production. In the future, as saprolite ore grades decline because of relatively high exploitation rates, the incentive to process the large untapped reserves of limonite ore will increase. The high cobalt content of limonite ore also makes it ideally suited to processing by a hydrometallurgical rather than smelting route. With only two exceptions, all saprolite smelting operations have a Class 2 nickel end product (largely ferronickel) and do not produce a cobalt by-product. As a result of technological advances, the modified ammonia leach process for limonite and transition ore as undertaken at Yabulu, now allows the production of pure nickel metal as a Class 1 product, along with significant tonnages of cobalt by-product. The mixed Ni-Co sulphide intermediate product of the pressure acid leach processing of limonite ore at Mon is converted to Class 1 nickel and cobalt metal at Fort Saskatchewan, Canada.

Jan 1, 1996

By Enichlmayr E

Lignin grouts are cheap and easy to get. They have some desirable properties, but they aag less used now because environmental pollution is often caused by Cr from the lignochrome component of the grout. Their usefulness was researched in an earlier paper on lignin as a grout from other viewpoints. A non-toxic grout FUL was made composed of furfural, urea and lignin. After initial tests, including tests by spinning regression design, some response equations in which FUL's properties are described were obtained. Optimum formulations have been established by using optimization methods based on response equations. The engineering quality was assured by formulations whose properties were measured in further tests. The mechanical feature of gelling sand was measured by means of triaxial tests. This provides a basis for using FUL grout in-situ. Finally, an in-situ experiment on FUL was completed successfully. The results were that cracks in stratum were filled or blocked, the gelling of FUL had high strength, and low permeability and consolidation were achieved.

Jan 1, 1988

This paper examines the broader implications of recent and ongoing changes in mineral resource managementå and reporting practices and the impact that these might have on mining companies. It is likely that an International Reporting Code will be developed in the near future, based on a number of National codes produced in recent years. However, this is only part of the reporting story, as an International Code brings with it a range of further issues to resolve. For the Code to be effective, there needs to be international recognition and perhaps licensing of Competent Persons and an expanded base of sponsoring professional bodies. Also, in an increasingly global business, shareholders, regulators and other interested parties need to know and understand the general processes involved in resource and reserve estimation and reporting in order to recognise companies that maintain the highest standards. There is a current trend towards greater scrutiny of company performance in a range of areas under the banner of corporate governance, and many changes are happening that will place greater disclosure burdens on all companies in the future. Good corporate governance means management of company assets for the benefit of the stakeholders. For a mining company, there is no greater asset than its mineral resources and reserves and directors are just as responsible for effective management of their mineral resources as they are for financial good practice. The paper looks at the relevance of corporate governance principles to mineral resource management and the changes that this could bring to the way that companies deal with regulators, shareholders, financiers and others. Finally, increased scrutiny and further regulation inevitably means greater effort by the industry and higher costs. Despite this the author believes that there are substantial offsetting benefits to be gained by companies prepared to take the initiative in improving resource management practices and communicating these improvements to shareholders. In order to achieve the benefits however, the industry needs to fully engage in the changes that are taking place û setting its own standards and working with the regulators rather than sitting back and being legislated against. Mineral resource reporting provides a good model of how this process can work and there will be other opportunities in the coming years as the industry seeks to develop best practice in mineral resource management. The author is an employee of Rio Tinto but wishes to point out that the views expressed in this paper are his own and not necessarily those of Rio Tinto.

Jan 1, 2002

By James D

Fletcher Challenge Limited through its subsidiary Grampian Mining Co Ltd has carried out an ore evaluation of one of New Zealand's largest known deposits of ilmenite located at Barrytown on the west coast of the -South Island, New Zealand.The ilmenite is located in a beach sand environment which has previously been mined for gold. Two analytical techniques were developed to quantify the resource. Considerable difficulty was experienced in this phase of the evaluation due to the presence of major inclusions within the ilmenite grains. Wet and dry concentration circuits, utilizing spiral, wet magnet, high tension and plate electrostatic separators have been G47designed to produce ilmenite from the ore. Studies to utilize the titanium content of the Barrytown ilmenite have been made. Recent work has been directed towards a titanium dioxide pigment process.

Jan 1, 1986

By Holliday RJ

The Imperial Smelting Furnace (ISF) was developed in Britain during the 1950's as a process which could produce zinc from a blast furnace. Since then it has evolved into an efficient means of producing zinc and lead from lower grade raw materials, both of primary and secondary origin. These changes have been in response to the need to improve the cost competitive position of the ISF in a climate of decreasing metal prices. The improvements at the Cockle Creek smelter of Sulphide Corporation Pty Limited have resulted from work undertaken in four main areas: 1. Changes in plant design and operating practice to give more stable furnace operation. 2. Improvements to the quality of sinter being charged to the furnace. 3. Improved monitoring of process variables and the formulation of control strategies based on the improved data. 4. Increased understanding of the processes occuring within the furnace shaft to allow predictive modelling to be undertaken. Work in these areas is still progressing but the work to date has resulted in a significant improvement in the production rate and efficiency of operation.

Jan 1, 1984

By D von Horn

Mineral sand orebodies are typically mined for their TiO2 content. Increasingly over the past 30 years, the major mineral focus has shifted from natural rutile to ilmenite and an acceptance that the latter generally needs some form of upgrading for economic conversion into TiO2 pigment. This upgrading obviously has a cost, and in conjunction with diminishing mineable feed grades, results in higher cost TiO2 units for chloride route Pigment Plant feedstocks. The net cost of feedstock can be significantly influenced by the recovery and sale of accessory minerals and by-products from the processing chain to the extent that some producers have the potential to achieve a zero net cost. Whilst slagging plants typically reduce net cost from rutile, zircon and pig iron revenues, operations supporting Becher type synthetic rutile operations have been limited to revenues from rutile and zircon only. A range of alumino silicate minerals show industrial potential, as does activated carbon, iron oxide and gypsum, by-products of the synthetic rutile process. Tiwest is a good example of a company maximising revenue from the accessory minerals as well as from by-products of the synthetic rutile process.

Jan 1, 2001

As an older member of The AusIMM, I received my 30 year æPearl AwardÆ in June and had my 50th birthday two weeks ago, I am honoured to be here today. I thank those responsible for their confidence in me and in my ability to hopefully hold captive a broad group of individuals who are here as equals, sharing an interest, no a passion in blasting technology and associated works à over the two days you will hear some excellent operational and technical presentations I am sure. But today I will digress; I want to talk about the importance of leadership and how it indeed can be the catalyst for success, improvement and change. There has been much written about leadership, its principals, the charismatic leaders, the doÆs and donÆts and so on à and I for one am not about to give you the Holy Grail; there are many experts with greater wisdom than I on this subject matter. What I do want to do is explore the application of this passion to examples within the world stage and some examples drawn from my experience in mining.

Jan 1, 2007

By M Hitzman, E P. Nelson, J Skarmeta

The Coastal Cordillera of northern Chile hosts the youngest and possibly best preserved iron oxide copper gold (IOCG) belt yet discovered and includes important deposits such as Candelaria and Mantoverde. The spatial and temporal relationships of hydrothermal alteration and mineralisation (Fe and Cu-Au) related to structural and lithologic features were investigated through geologic mapping and petrographic and geochronological studies along two W-E-transects crossing the Coastal Cordillera to the north of Vallenar. The project aimed to determine vectors for district-scale and regional exploration. Along with magnetite-apatite deposits (Central Iron Belt) and manto-type copper deposits, the IOCG deposits are hosted in a N-trending volcano-sedimentary sequence formed in a Jurassic to Early Cretaceous arc/back-arc setting (Sillitoe, 2003; Ramos and Alemßn, 2000). Calc-alkaline plutonic rocks intrude and metamorphose the volcano-sedimentary sequence, and become progressively younger from west to east reflecting a shift of arc magmatism (to Paleocene in the far east). From west to east along the Agua Grande-Chehueque profile, four domains of different economic potential are recognised. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

One of the more recent developments within the mining industry has been the adoption of formal continuous improvement programs. A continuous improvement (CI) program was launched across Kalgoorlie Consolidated Gold Mines (KCGM) in early-2002. The purpose of this program was to identify further operating improvements within departments. The focus of the continuous improvement program was not only on the areas of the operation which were performing below expectations but also on areas of the operation which were performing well but could still be further improved.The effectiveness of a continuous improvement program depends on the stability of the processes in place and the participation of many employees from all levels of the business.Continuous improvement has had some successes and failures at KCGM and this paper will discuss both within the open pits department. Further improvements that could be made to the process will also be discussed. Kalgoorlie Consolidated Gold Mines Fimiston operation is located in the Kalgoorlie Goldfields and it the largest gold mine in Australia producing over 800 000 ounces of gold per annum.

Jan 1, 2004

Since 1865 when Congress moved to create a Federal Mining Bureau, successive legislations have given rise to the current '!Federal Coal Mine Health and Safety Act, 1969. Coal beds from 22 feet to 20 feet thick are mined under covers from 50 to 2800 feet with full and partial pillar recovery equally popular and accounting for a total of 54% of the mines. Pillar recovery and roof support practices vary, and each operator must submit an overall roof control plan (within specific guidelines) for approval before undertaking any development. The guidelines relate to dimensions of openings, details of support, sequence of extraction, limits of extraction and caving details. Experienced and professional staff of M.E.S.A. provide roof control plans and make inspections and grant-approvals of principles of support and minimum support in pillar extraction, with provision for modifications with time. Guidance is given with training programmes and standards of supervision. All of these aspects are approached in the spirit of the Congress declaration that the first priority and concern must be the health and safety of the miner.

Jan 1, 1974