Search Documents

Many aspects of best practice resource evaluation do not create value, but poor practice can certainly destroy value. Generally companies prefer to present how their good practice adds value and for this reason few publications exist on examples of how poor practice can destroy value. However in big and small companies there are many previous and current examples of poor practice destroying value. The incremental expenditure required to move from poor practice towards best practice can be looked upon as insurance against destroying shareholder value. Examples of how poor practice in geology has destroyed value are presented as well as the improvement model used by BHP Billiton to add value and insure against destroying value.

Jan 1, 2002

Mine scheduling is a process which represents what happens in a mine over time. An optimised plan involves selecting the best workable plan which meets a stated objective. This paper discusses some of the theory and philosophy behind mine scheduling and explains how scheduling is a step in the total iterative mine planning process. Several schedules may be necessary before arriving at a mine plan which can be considered optimal. A description of broadbrush and detailed scheduling is given and the features of computer assisted scheduling are also described. The use of mathematical modelling techniques in conjunction with scheduling to optimise the mine plan is explained. The need to incorporate these techniques to optimise the whole mining system rather than only a part, is emphasised.

Jan 1, 1991

Hilton Mine is located 20 km north of the city of Mount Isa and Isa Mine in far north west Queensland. The sealed road used by the 500 employees to commute from the city is part of the Barkly Highway linking Mt Isa to the Northern Territory.Although discovered in 1947, major underground development did not start until late-1982 and first cut-and-fill production in mid-1987. The J53 exploration shaft was sunk in 1970-73 and the main P49 shaft in 1973-75. Since January 1990, most of Hilton ore production has been treated in the Hilton Concentrator, and concentrates trucked in slurry tankers to Isa for smelting or shipping.

Jan 1, 1993

The mineral sands industry in Australia can contribute much more sig- nificantly to economic development beyond the year 2000 by increased production of constituent minerals such as ilmenite, zircon, rutile, leu- coxene and monazite from existing and new resources, and especially from downstream processing to intermediate and finished products based on these resources. The end-use areas for mineral sand-based products include those products whose demand is tied to general economic growth, such as paints and plastics, and refractory bricks for the steel industry. High techno- logy applications such as zirconia ceramics and super-magnets are indica- tive of new developments in technology which provide considerable scope for expansion at higher rates than overall western world economic growth. An optimistic outlook for the industry is outlined, based upon a brief review of opportunities.

Jan 1, 1988

A continuous casting machine, of the Concast curved mould design casting billets in four strands, was commissioned at the Newcastle Works of The Broken Hill Proprietary Co. Ltd., in November, 1967. Quality assessment of early casts from this plant indicated that steel cleanliness was sometimes inferior to that of equival- ent ingot cast steel. Extensive trials to develop a modified deoxidation technique were not successful in improving clean- liness to the desired level. A "contra-flow" gas shroud, to cover the steel stream between the tundish and the mould, was developed, and proved successful in achieving the required levels of product cleanliness. The inclusion content of six grades of steel ranging in carbon content from 0.10 to 0.70 per cent is examined, and an attempt is made to explain theoretically some of the results obtained.

Jan 1, 1972

Gold mining commenced at Telfer in Western Australia in 1977. Ore mining was carried out by owner equipment and personnel with waste stripping by a contractor. Initial ore reserves were in predominantly high grade, geologically simple reef structures. A mining method was developed using dozers to selectively mine the ore bearing horizons with a minimum of dilution. As the mine has developed the simple, high grade ore reserves have been progressively replaced by more geologically complex, lower grade reserves. In turn, mining methods have evolved to extract this ore by the most appropriate methods. On-going attention to ore mining practices will ensure that project profitability and viable mine life are optimised.

Jan 1, 1986

By R F. Weinberg, R A. Armstrong, A G. Tomkins

We investigated the duration of formation of the giant Ok Tedi porphyry copper-gold deposit in Papua New Guinea using zircon SHRIMP U-Pb dating. The intrusions that host the Cu-Au mineralisation have a maximum age of 1.43 ¦ 0.22 Ma. Since previously published K-Ar dates on the same intrusion constrain the last thermal event at 1.11 ¦ 0.05 Ma, we conclude that the magmatic-hydrothermal event that produced the deposit lasted ~0.45 million years (Myr). A comparison of Ok TediÆs calculated volatile fluxes with those from arc volcanoes and active mineralising hydrothermal systems suggests that the efficiency of metal deposition is a key factor in determining the duration of deposit formation. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

Polarization phenomena associated with the use of an agitated bed of particles as an electrode for metal deposition were studied. The concentration polarization at this type of electrode is much smaller than that occurring at a fixed or moving electrode surface. Agitated particle electrodes can be used to electro-reduce copper from solutions over a wide range of concentration and at cur·rent densities up to 2000 AIsq. ft. of bed cross section.

Jan 1, 1971

A new approach to strategic planning, the Life of Business Optimisation System (LOBOS) optimises production systems from the scale of stopes in a single mine to an entire business strategy consisting of multiple mines and products competing for capital and processing capacity. LOBOS has optimised cash flow for a wide variety of operations, including large metalliferous or coal mines and as an aid to high-level strategic business optimisation solution to multi-mine/processing/product complexes. This paper discusses the application of optimisation technology to strategic planning with an emphasis on project evaluation with examples on the application of LOBOS to a variety of recent projects.

Jan 1, 2007

The procedures for an audit and review process upon which continuous improvement programs may be based are described. The case for regular audits of mining operations to establish performance trends is advanced. Analysis of performance data using the parameters of the capacity equation used in conjunction with learning curves is described. The extrapolation of learning curves in performance target setting, operating and capital cost budgeting is advocated.

Jan 1, 1992

In his letter of resignation as General Superintendent of the Broken Hill Associated Smelters (BHAS) prior to taking up aconsulting position at imperial Smelting, G.K. Williams wrote that he considered his major contributions at BHAS were:the development of large scale sintering machines;the double tuyere-row blast furnace; continuous lead refining.Despite his well deserved reputation as a scientist, based on his advancement of the metallurgical chemistry underlying lead refining processes, Williams reveals that he considered commercial implementation as the ultimate measure of technological success. Furthermore, he clearly did not differentiate between the scientific and the empirical as a means of achieving that end.

Jan 1, 1985

In the exploration of an area proposed for the establishment of an underground colliery, consideration of all land and mining titles and consents has early priority. Environmental aspects have become more meaningful. Preliminary assessments of previous geological knowledge, together with new geological and geophysical data from surface investigations, condition the decision to proceed with costly diamond drilling programmes. Methods other than fully cored diamond drilling have a useful application in appropriate circumstances. Drilling exploration is conducted in stages of increasing density of-hole spacing to the point where, with holes at 1 km centres, reserves are categorized as measured. The programme is subject to constant review in the light of market changes.

Jan 1, 1976

By R Gaze, J Horton

Block models generated with all linear interpolation algorithms contain inherent smoothing that typically results in an underestimation of grades and overestimation of tonnes in resource estimates. For mineral deposits that are anticipated to be exploited by underground mining methods excessive smoothing may result in materially misleading estimates of Ore Reserves. To account for smoothing in the open pit mining environment recoverable reserve techniques such as indicator kriging and uniform conditioning are employed to provide non-spatially located proportions of the large blocks above the cut-off grade. These models are not suitable for underground mine planning where the actual location of material above cut-off is required to design its extraction. To correct for excessive smoothing it is proposed to modify the ordinary kriged block estimates a posteriori using an affine correction with a local variance adjustment factor. The proposed methodology is demonstrated for a base metal deposit during a feasibility study.

Jan 1, 2009

By G B. Siddall

The paper examines the current state of equipment and circuit design, with reference to Australian practice. Following a review of the changes in milling applications over the last 15 years, developments in mill design are examined. Current issues include trunnion versus shell support; drive type and economic analysis for comparison of the various systems; the efficiency of the mill discharge system for slurry and pebble removal, and lining configuration. Peripheral problem areas such as pebble crushing and classification are briefly examined. Circuit design issues are reviewed. The decision to modify the traditional primary crushed feed is examined with reference to recent and proposed installations. A retrospective look at fully autogenous installations and their successes is presented, and current views on increasing throughput are assessed. Finally, future developments are anticipated in mill design and control, and competing processes are identified.

Jan 1, 2002

The topic for my address is Sharemarket Floats - Issues for Expert Valuers. I've decided to focus on three areas where current practice in the preparation of prospectus valuation reports for resource companies might be improved. My central theme is that the valuer for a float should augment the usual assessments of the value of the company or its assets, with some input on the way the share market might value the company's shares when they are listed. I will then look at the valuer's role in relation to vendor consideration, last I will look at his role in providing investors with some input on the risk dimensions of the new company.

Jan 1, 1989

Both blast furnace and steel furnace slags have been used extensively and successfully on main line railroads in the United States for more than 25 years. Annually, these slags are being used as ballast at the rate of about 4 million tonnes of blast furnace slag and 1 mil- lion tonnes of steel furnace slag, much of it on main line with 90 metric tonne car loadings. More steel furnace slag would be used if it was available. Both slags meet all the specification limits of the American Railway Engineering Association. Actual use on high density rail- roads has confirmed the long range economics of their use. Comparison of laboratory tests, such as Los Angeles abrasion, with actual field per- formance has shown conclusively that commonly used laboratory tests can not be used to accu- rately compare the quality of various types of ballast materials.

Jan 1, 1979

The commercial outcomes from new mining projects or brownfields expansions often fall short of feasibility study forecasts because of technical under-performance. This paper: reviews past feasibility study performance; identifies the key drivers of underperformance; and proposes actions that can be taken to manage the risk of underperformance. There have been a number of published reviews of feasibility study performance since the 1970s. The results of these studies are summarised together with recent unpublished data. Key drivers of underperformance include inadequate metallurgical testing, simultaneously pushing a number of project parameters beyond comfortable limits and a failure to recognise the linkage between mining rate and head grade. Actions can be taken during the data acquisition phase and during the feasibility study to manage project technical risks. These generally require a more flexible approach to study management than can be achieved under a ælump sumÆ contract.

Jan 1, 2003

By Ranford LC

Modern, research-based approaches to mineral exploration are essential to the future maintenance of the mineral industry. These need to fully utilise the rapidly expanding growth of understanding of the evolution of the earth's crust, and be properly integrated with advances in understanding of chemical and physical processes involved in ore formation. BMR has a major role to play in supporting the growth and utilisation of this research base, as well as maintaining the national geological and geophysical bases which are essential both to tactical and strategic interests of Australia and of its mineral industry. The objective development of data-process modelling is one target of such strategic research based on a more integrated approach to research by BMR, mineral companies, CSIRO and the universities with emphasis given to promoting positive feedback during research activities. Examples of the success of strategic research in Australia and overseas are noted in the Text.

Jan 1, 1986

Modern minerals projects face serious challenges in earning and maintaining acceptance by their key stakeholders. Factors which underpin effective response to managing these challenges include consideration of public affairs issues from the earliest planning stages, building robust alliances with a range of influential partners, developing a level of transparency in all operations and decision-making and integrating activities towards resolving key strategic issues. Effective community relations is vital and there are a number of elements common to the best approaches. These include senior management support and involvement, appropriate involvement in project decisions and activities by community members and company responsiveness to community expectations. The project's operations manager and executive team must fully commit to developing the capability and processes to meet these challenges. They require a whole of project response and it is not an option to manage them peripherally.

Jan 1, 1997

The various functions of public relations are playing an increasingly important part in the activities of the many companies now engaged in oil exploration in Australia.Several of the larger exploration companies, notably West Australian Petroleum Pty.Limited, Ampol Exploration Limited, Caltex Oil (Australia) PtSr: Limited and Australian Oil and Gas Ltd. (and its American Associate Union-Kern), employ staff or consultant public relations specialists. In, most of the other companies now exploring in Australia, public relations are handled within the company, directed from the highest executive level.The object of public relations in.the oil industry is. to create in the public mind an impression favourable to the industry as a whole and'the company -or group of companies with which the public relations officer is associated.

Jan 1, 1962