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By Blackwood R. L, Crichton G. P

In recent years, the value to Australia of the introduction of a system of resource rent taxation on the mining industry has been frequently debated. The forms that this rate of return based tax could take, and the impli- cations on government revenue and mining com- pany profitability have been discussed at some length. Further, the selective application of this taxation scheme to certain mining industry sectors has received considerable attention. This study takes the form of a survey of the taxation history of one significant Australian mining venture, the Mount Lyell Mining and Railway Company. The conditions faced by this company during its history are used as a base for the imposition of rent taxation schemes. Comparisons are drawn between the historical taxation liability of the company and that which would have been incurred if a resource rent form of taxation had been in existence. From the results of the study, it can be concluded that while the company can be con- sidered to have been a successful enterprise during most of its history, it has not achieved a level of profitability which would warrant the collection of any form of excess profits Tax.

Jan 1, 1979

By A Weeks an, R Bertinshaw, S Khosrowshahi

Good mining is central to any approach to value tracking. Good mining occurs where the ore is correctly delineated, measured and fed to the mill. This process is usually referred to as grade control, ore control or quality control. There are now ways to measure the efficiency of this process, such as by using conditional simulation, and a brief synopsis is presented. Resource estimation is the foundation of ore reserve estimation, which should enable useful prediction of the expected metal to be recovered from mining and milling. Significant improvements have resulted from applying new techniques such as the Chain of Mining (CoM) method, which models the mining process. Again, a brief synopsis is presented. Tracking value from the mine through the mill implies a linear sequence of processes that can be modelled. Reality is more complex and there are error components, feedback loops and breaks in the Chain of Value. Modelling the total production process in a number of operations is considered, including the various impacts on producing reconciliations. Procedures are also discussed for handling a number of difficult issues such as: different data supports, stockpiling strategies, blending from multiple ore sources, blast movement and underground ore extraction.

Jan 1, 2002

Copper was first produced in Australia in 1844, at the Kapunda Mine in South Australia, and, by 18i>0, production exceeded 2,000 tons of copper a year. Output increased ,steadily, reaching a peak of 14,00Qo tons a year in 1867 and 1868, when the Burra Burra and Kapunda Mines in South Australia and the Peak Downs Moine at Clermont, Queensland, were at the height of their production. At this period, Australian copper formed a considerable percentage of the world's supply, its output equalling, for a short time, that of the United States. Production declined to between 3,000 and 4,000 tons a year after the closing of' these three mines between 18717 and 1879, and, at this stage, the Australian output came chiefly from the Wallatoo and Moonta mines in South Australia. About 19000, it began to rise again, with the extension of the railway to the copper fields of Chillagoe and Cloncurry, and, between 1905 and 1912, was at its greatest, with a maximum of 47,774 tons of copper in 1912. During this period, Australia contributed 4,7 per cent. of the world's annual production, and ranked among the six major copper-producing countries of the world (Table 1).

Jan 1, 1943

By Hebbard GJ

Vertical crater retreat mining is being used at Zinc Corporation, Limited and New Broken Hill Consolidated, Limited for pillar recovery between previously mined and filled stopes. In order to increase productivity in the older lead lode areas of the mine, particularly in the lower grade sections around the keel of the orebody, score form of longhole stoping was considered necessary.Due to poor ground conditions in the country rock surrounding the ore and the requirement to provide sane wall support during mining, primary VCR mining has been utilised in these areas.At Zinc Corporation, several stopes have thus far been mined by a hybrid longhole stripping - VCR method.

Jan 1, 1985

By G McSpadden

At September 2001 the beneficiation plant at BHP Billiton Iron OreÆs Mt Whaleback mine is set to treat 9.5 million tonnes per annum (Mtpa) of iron ore, 40 per cent better than original design. This paper describes the steps, decision-making processes and innovations used to increase capacity at minimum cost. The plant was designed in 1979 to operate at 1133 t/h for 6000 hours per annum, treating 6.8 Mtpa. Sufficient suitable contact ore was unavailable and feed was finer than planned. The plant was designed with minimum surge capacity between multiple process units. It had never reached design capacity. In 1993 a study by Fluor Daniel to treat increased tonnage resulted in modifications to improve plant operations. Efforts to expand production by increasing reliability did not achieve the desired capacity. NJ Morrow (Pty) Ltd (NJM) conducted a technical audit in 1996 with process evaluation by Mineral Processors. Replacement of operator interface and PLC logic in 1997 made plant operation and diagnosis easier. Involving operators in logic development enhanced their plant knowledge. Fluor Daniel Simulation developed a simulation model of the process. Mineral Processors and NJM reviewed the model findings, recommended metallurgical improvements and developed preliminary designs and costs. BHP Engineering produced a detailed design with a cost estimate of $A34 million. After analysis and revision of the design, a $A10.4 million upgrade to 8.5 Mtpa was carried out. Detailed modifications to the process units, particularly the HM drum plant, allowed significantly higher capacities and improved metallurgical performance. The target capacity was achieved in June 2001. Further modifications are progressing to treat lower-grade ores.

Jan 1, 2002

Backfil ling of excavated Sub Level Open Stopes has been underway since March 1989 and as at December 1992 some 1 100 000 cubic metres of Cemented Aggregate Fill have been placed. During these three years significant developments in fill quantities, types and cost have taken place.Operational improvements have reduced the quantity of Cement Aggregate Fill by 40 per cent. These results have been achieved by:ò rescheduling stopes,ò designing smaller primary stope, and ò use of uncemented rockfill.Unit cost for Cement Aggregate Fill have fallen in the order of 50 per cent through:improving fill hole reli ability,simplified barricade construction procedures, reducing the cement content,ò substituting dune sand for deslimed mill tailings, ò improved maintenance at the Backfill plant, and ò renegotiated site freight agreement.This paper will review the historical developments of backfill use at Olympic Dam.

Jan 1, 1993

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Jun 1, 2010

The increasing global demand for rough materials forces almost every mine to look at the mechanisation in their processes. This will not onlyimprove performance but with safety issues becoming more and more prevalent, the need for the introduction of mechanisation technologies to mining applications is essential. Ongoing developments are occurring in almost every field, ranging from basic developments to specialised mining. Mechanical tunnelling and shaft sinking have set the standards regarding safety, profitability and environmental protection. Different machine types and working principles have been developed to suit the geological and hydrological requirements of tunnelling projects worldwide. Continuous activity in research and development leads to constant optimisation of tunnelling performance.

Jan 1, 2008

Basic Oxygen Steelmaking (B.O.S.) commenced in Australia in December, 1962. Two 200-ton furnaces were installed initially at Newcastle with a 50-ton furnace coupled to a continuous casting machine added in 1967. In 1965, two 100-ton furnaces were installed at Whyalla plant and two 225-ton furnaces are nearing com- pletion at Port Kembla to commence oper- ations in 1972. Plant layouts in each centre differ due to changing circumstance and increasing knowledge of the B.O.S. process since 1962. Raw materials are a most important factor for good operation of the process. Most materials come from within Australia but some are imported. General operating practices are similar in each plant, although treatment of fume at Port Kembla will be by the OG (Oxygen Converter Gas Recovery) Process as against electrostatic precipitators in Newcastle and Whyalla. Special alloy steels as well as plain carbon steels can be made by the B.O.S. process. Production potential of the process in Australia has yet to be fully utilised with 45 per cent of steel production coming from B.O.S. In 1971.

Jan 1, 1972

By Elford H. S

Australia has many potentially important tin deposits, particularly on the eastern shore of the continent and in Tasmania. A number of these have been worked on a meagre scale, while some of them, because of metallurgical, transport, and other difficulties, have not as yet been developed.Believing that the full development of the tin fields of the Commonwealth of Australia is in part dependent upon the adoption of the most efficient methods of milling and smelting, the Development and Migration Oommission arranged for the first-mentioned author to visit the mining fields of Cornwall, one of the oldest tin-producing districts of the world, and prepare a report for the information of the Commission.This paper, now presented to the Australasian Institute of Mining and Metallurgy with the hope that it will assist the full development of tin mining in Australia, is the joint work of both authors.For over two thousand years tin has been produced from the Cornish mines. Even the ancient Greek historians made mention of tin mining in Cornwall, and it is probable that during the earliest periods the mining was alluvial. As early as 1602 a stamp battery working in Cornwall was described, and in 1671 calcination and buddling was a recognised scheme of treating pyritic ore. In the first half of the 16th century the output of tin from Cornwall was 700 tons per annum, and, from then on, production increased to the maximum in 1914 of 6500 tons. At present (Oct., 1929) the Cambourne-Redruth area produces over 95% of the Cornish tin output. This area includes such mines as the South Crofty, East Pool, Dolcoath, Parkanchy, Polhigey, and Wheal Kitty. The remaining 5% is largely supplied by the Levant and Geevor mines at Pendeen, St. Just area, near Land's End.

Jan 1, 1930

In order to understand the technique, basic theoretical principles of radiation emission and in- strumentation theory are reviewed. Methods of surveying, reduction of data and interpretation are outlined. Other applications of the technique (e.g. in airborne geological mapping), as well as its specific use in uranium exploration, are discussed. By means of case history-type examples the successful applicant of gamma-ray spectrometry, as a tool in Australian mineral search, is demonstrated.

Jan 1, 1969

The Gympie Goldfield was the sixth largest producer of gold in historic terms in Australia. The Joint Venture Agreement between BHP Gold Mines Limited and Devex Limited was signed in January 1987. Since that time, some $20 million have been spent on underground and surface exploration work in the southern portion of the goldfield. The project is of considerable interest as the dewatering, rehabilitation and equipping of an old rectangular timber-lined shaft has been undertaken. The project is located in Gympie, a city of 10,000 people. The issues of dealing with urbanisation and associated environmental aspects are vital to the success of the project. An outline of the project and the geology of the mineralised structures follows:

Jan 1, 1989

The Elura Orebody consists of a number of parallel, vertically oriented pipe-like structures of pyrite-sphalerite-galena mineralization located at the core of a structural dome. Concentric zoning of the mineralization into an outer Siliceous, intermediate Pyritic and inner Pyrrhotitic Zone has been previously recognized and is used in routine geologic modelling of the lead, zinc and silver grades.Statistical analysis of the metal grade distribution in the orebody has confirmed the importance of the mineralogical zones in the understanding of grade trends. The gradational nature of intra-zone boundaries, especially those related to the subjective definition of the Siliceous Zone, are apparent in the statistics.

Jan 1, 1990

The main features and recent developments in the processes of benefication and extractive treatments of tin ores are reviewed. The need for development of processes to recover fine tin, tin from low-grade complex ores and from hard rock resources is indicated. The progress in understanding of slag-metal interactions and developments of fuming processes on industrial scale is delineated. the processes and prospects of hydrometallurgical and chlorination methods are briefly indicated.

Jan 1, 1992

The role of the mine geologist in a business perspective is self-evident to some, but to others it may be a new concept. All mine geologists need to know exactly how they add value to the business if they are to be successful. Alternatively, if they do not add value, then they will become redundant. This paper seeks to understand some of the contributing problems that hinder the mine geologist from operating in a business perspective. In doing so, a new context (for some) is proposed to aid the mine geologist and the operation gain greater value from geology. The proposal suggests how to ensure that the activities of our geologists are intrinsically linked to the business process that we are involved in. The mine geologist can and must play a pivotal role in the success of an operation. To do this, they must understand some principles of business such as:process, customer/supplier relationships, and organisational structure. Our geologists must know the business objectives, understand the product that the customer needs and use their geological skills to deliver the product safely, on time and to specification. As geologists, we can be instrumental in ensuring that the operational environment is structured in such a way that maximum value is realised, not only from the mine geologists but the entire site team. In doing so, mine geologists will realise their full potential in delivering the outcomes the business demand, and therefore be recognised as strong contributors to business success.

Jan 1, 2000

Powercoal Pty Ltd operates eight underground coal mines in New South Wales and produces coal for both domestic power stations and the export market. Approximately 40% of total production is from continuous miners. Over the past five years, place change mining methods have been introduced to improve productivity from continuous miners. This has involved utilising the existing coal clearance system from the continuous miner to the ratio feeder using trailing cable shuttle cars.By late 1996 average productivity at Cooranbong Colliery using this system had plateaued at 800 tonnes per eight hour shift. A number of factors were identified to increase average productivity to 1500 tonnes per eight hour shift. An improved coal clearance system was one of the factors identified.

Jan 1, 1998

By Bearman R. A, Parkin R. M

In the comminution industry cone crushers are widely used for secondary and subsequent stages of size reduction. Traditionally cone crushers have been operated and monitored manually. Alteration of discharge setting is now commonly achieved via hydraulic means, however, compensation of liner wear can still involve plant shutdown and loss of production. Drift in discharge setting due to liner wear is still a major problem that must be addressed to improve product quality, consistency and reduce recirculating load. The continuous demand for better quality products and the high cost of reprocessing or discarding unsaleable material, highlights the need for re-examination of the technology associated with the crushers to ensure optimum control and system efficiency. A collaborative project between Pegson Ltd, one of the leading UK manufacturers of jaw and cone crushers, De Montfort University Leicester, and Transfer Technology plc was established to address the technological requirement for automation of the control of cone crushers. The machine chosen for the study is a 900 Autocone cone crusher manufactured by Pegson Ltd. The design philosophy is based on a mechatronic approach providing a complete solution through a distributed network of intelligent sensors, artificial intelligence technology and adaptive control. The modular design of the system ensures a progressive sophistication in technology that allows the automation to be phased in as required. This will ensure maximum benefits to all sectors of the aggregate industry. It is estimated that the automation will result in savings of around ten per cent. The savings will result from minimising the production of unsaleable products by reliable condition monitoring and automation of the control and maintenance of system parameters to optimise system efficiency. Extension of the methods and principles into the mining sector is anticipated. The control over the size of crusher product will offer great benefits to the mining industry with significant implications for subsequent milling and beneficiation processes.

Jan 1, 1995

By Sutherland R. A, Rawling K. R

The Nanisivik Mine is located 750 km north of the Arctic Circle at the north end of Baffin Island in the Canadian High Arctic, and has been in production since 1976. The paper describes the regional and local geology and the current mining and mineral processing operations, including recent innovations in each area. The Nanisivik zinc-lead deposits comprise Mississippi Valley type sulphides in a block-faulted sediment sequence of Proterozoic age. The deposits formed in two mineralizing stages by replacement of the carbonate host rock. Exploration techniques adapted to the permafrost environment include high frequency EM and ground probing radar. Core drilling is done with calcium chloride brine but trials with heated flushing water indicate potential for cost reduction. The predominant mining method at Nanisivik is room and pillar. Cut and fill is used in some satellites to the main zone. Due to the permafrost, dry drilling is employed in the underground mining. The permafrost enhances ground stability, permitting large underground openings and, as a result, the use of relatively large scale mining equipment. For power conservation, a remote control system for the ventilation fans has reduced mine power costs. The milling of the simple coarse-grained ore in an arctic environment requires special techniques in the design and operation of the plant for materials handling, utilisation of waste heat, reagent selection and tailings disposal. Regulated heavy metal contents in effluents discharged to the sensitive environment are achieved by natural processes. A recent change from sub-aqueous disposal of tailings to beach type deposition within a cell in the tailings area is reviewed. Planning closure of the property presents special problems and an opportunity for innovative techniques. Approximately 25 per cent of the employees at Nanisivik are drawn from the Inuit population of the Canadian Arctic. As the first permanent industrial activity in the High Arctic some innovative approaches to employee relations were required which have resulted in a very stable, culturally mixed community in a remote location.

Jan 1, 1993

By Walraven F, Knott G. G

Using a typical small logging instrument (Neltronic KPD), a natural gamma reference section for part of the Brockman Iron Formation and part of the Mt. McRae Shale has been established in the Newman area. This is compared with the stratigraphic type section of Trendall and Blockley (1968). Folding and faulting are recognised using natural gamma logs. Because of the confidence with which stratigraphic horizons can be identified, less expenditure on diamond and percussion drilling is required to confirm stratigraphic position. Using natural gamma logs as stratigraphic control the apparent thinning of the Banded Iron Formation during iron enrichment is Demonstrated.

Jan 1, 1973

By B F. J Kelly

Multiple-point simulation is a family of methods used to generate conditional facies simulations that present the same spatial dependence as a user-defined training image. The main advantage of using a training image is the easy integration of geological concepts in numerical subsurface models. The strength of multiple-point methods is that it allows making the best use of geological expertise when data are too sparse for inferring a model of spatial continuity. However, despite being appealing to geologists, the multiple-point methods are often not used in practice due to the difficulty of building complex 3D training images that contain realistic features.A new framework for multiple-point simulation is presented that involves small and simple training images. The main idea is to use random transformations to expand the range of structures available in the simple training image. The training image is not regarded any more as a global conceptual geological model, but rather a basic structural element of the subsurface. Complex geological structures are obtained, whose spatial structure can be parameterised by adjusting the statistics of the random transformations, based on field data or geological context. In most cases, such parameterisation is possible by adjusting two numbers only. One advantage is that the training images are so simple that they can be easily built even in 3D. The method allows building 3D models that reproduce shapes corresponding to a desired prior geological concept and are in phase with different types of field observations, such as orientation, facies or geophysical measurements. The flexibility of the approach allows for naturally integrating different types of data. This is demonstrated on an example involving seismic data assimilation. Examples where complex 3D folded structures are built from a simple training image and a few orientation data are shown.

Sep 26, 2011