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The basic model for the evaluation of any coal-bearing property is the cash flow projection, the major components of which are operating costs, capital charges, taxation and revenue. A range of cash flow projections can be produced by varying the assumptions which underlie the operating costs, by assuming various forms of capital funding, by making assumptions as to future taxation and by speculating upon the present and future market value of the product. As for any model, the informational inputs and assumptions are vital because, no matter how sophisticated the processing, the informational inputs and assumptions cannot be improved by it. That is to say, the validity of the output (the total evaluation itself) cannot be of greater certainty or significance than that of the inputs. The total evaluation can of course be expressed in a number of ways such as the Discounted Cash Flow (D.C.F.) Rate of Return, the Net Present Value or, the Payback Period. The foregoing statement may seem trite. However, it is necessary to be clear about it so as to avoid unnecessary complication and a preoccupation with techniques as opposed to the informational inputs and assumptions. So far as techniques are concerned, much has been written and said about them during the last decade. Most of us have heard, if not always understood, something about probabilistic models, Monte Carlo simulation, sensitivity and risk analysis to say nothing of inflationary costing and the relative merits of developing cash flows in terms of current or constant money. Those techniques have their value, particularly if they can serve to illuminate conclusions which could not be reached on a simple and even perhaps on an intuitive basis. I am, however, reminded of one major coal mining project in which 20 or more major variables were identified, many cash flow projections were run on the computer and a detailed sensitivity analysis was carried out. The major conclusion reached was that the D.C.F. Rate of Return was predominantly sensitive to variations in selling price and operating cost. Of course, the funding and fiscal elements of a cash flow projection have to be dealt with as rigorously as possible. However, in the development of any coal property, capital requirements and taxation are, in part at any rate, dependent upon the assumed operational parameters. If the latter are misjudged, the whole evaluation process is deeply affected. The same is true of revenue, in the sense that, the positive cash flow is a function of output as well as selling price and again, misjudgements about achievable and maintainable levels of production also deeply affect the final evaluation. I shall try to underline the fundamental influence of the technological factors upon lead times, capital costs, operating costs, taxation, funding and the achievable and maintainable levels of production. In turn, these affect the whole question of coal property evaluation and indeed, the likely success or failure of any coal mining venture. I make no apology therefore that this paper does not set out to discuss the more esoteric aspects of the evaluation process but rather, directs attention towards some of the informational inputs and assumptions which merit clarification and discussion.

Jan 1, 1975

Porgera is located in the Central Highlands of Papua New Guinea. Porgera Joint Venture treats a high grade epithennal gold deposit. Most of the gold occurs as submicroscopic particles in a sulphide matrix although there is some quite coarse free gold. Anticipated gold production is 900 000 oz per year for the first six years of operation.Stage I of the treatment plant consisted of a concentrator and leach/CIP Circuit. It was commissioned in August 1990. Design throughput was 1500 tpd with an anticipated gold recovery of 60 per cent. Throughput achieved was actually 1850 tpd with an average gold recovery of 69 per cent. CIP tails were accumulated in a pond awaiting retreatment by pressure oxidation.

Jan 1, 1992

In Australia a social impact assessment (SIA) is generally required prior to the approval of a mineral resource extraction or processing projects as a part of the Environmental Impact Assessment (EIA) process. In recent years there has been increased attention on the adequacy of the SIA process applied in major project assessment. Most applications have focused on the impact identification process with little attempt given to the community negotiating power over how impacts will be addressed. The impact assessment tends to occur at a single point in time, with no subsequent re-evaluation or ongoing social impact management and monitoring process. The assessments rarely specify how responsibilities for impacts on communities may be apportioned between project proponents and government, and have been inadequate in dealing with cumulative project impacts. In Queensland, concern about these shortfalls have led to the release of the Sustainable Resource Communities Policy 2008 and requirements for social impact management plans (SIMP) to be developed for each resource development in the State. In this paper a 'pressure-state-response' approach to impact assessment is used to develop an 'impact-response-monitoring-evaluation' (IRME) framework that can be applied to ongoing evaluation and monitoring of social impacts. The framework is applied to coal resource developments in the northern Bowen Basin in Queensland to identify core requirements in a SIMP. The IRME framework is flexible enough to be implemented at various spatial and time scales, for the wellbeing of the local and regional mining and non-mining communities in Australia. The framework can be further examined in other mine developments and could be integrated with the existing mining or environmental protection acts.

Jun 1, 2010

By Hayes J. A

The satisfactory ventilation of an extensive coal mine is a subject which requires continual attention from all concerned.It must be remembered that a colliery contains many miles of workings, extending in all directions and throughout which noxious gases may be given off either naturally or by oxidation of the coal; fumes from explosives will be produced, dust will be gathered and carried in suspension, and water will be evaporated, producing a high humidity. Hence a considerable quantity of air in movement must be available to provide sufficient oxygen for men and horses, as well as to dilute and sweep away impurities, and maintain a tolerable degree of coolness.To maintain these conditions a modern colliery is divided up from the main ventilation shafts or adits (as the case may be) into a system of main airways, and in the working districts is further subdivided into district splits. To initiate the air movement, large centrifugal fans with a displacement capacity of up to 400,000 cu. ft. of air per minute are installed, generally in drifts off the upcast shaft, or adit, and at the return end of the ventilating circuit. These fans are thus exhausting fans and by producing a region of low density bring the heavier air at the other extremity of the circuit into movement to correct the difference in density, so far as it is not prevented by the frictional resistance of the airways. A flow of air is thus established, and it is obvious that to enable this volume of air to be as great as possible, the frictional resistance of the mine airways should be maintained at the lowest practicable figure. To this end, main airways should be as large as possible, have sides as smooth as practicable, and be straight, any necessary bends being of large radius.REQUIREMENTS OF THE VENTILATION SYSTEMThe New South Wales Coal Mines Regulation Act contains stringent provisions on requirements of the ventilation system. The main points are expressed in the following extracts:"In every mine which is in operation, unless a certificate of exemption from compliance with this rule has been granted by the Minister, whether any person employed therein shall be...

Jan 1, 1947

The SAG milling circuit at Paddington was designed on limited bench testwork and since commissioning with the exception of some mechanical problems has performed well.

Jan 1, 1987

A computer programming language known as GPSS is described and possible applications for the mining engineer are presented. The language is continually being upgraded with improved versions appearing about every three years. The tremendous power of the language is considered by comparing it with standard engineering programming languages, such as Fortran or Basic. Sample problems that can be solved using the language are indicated. The advantages and disadvantages of the languages are also discussed.

Jan 1, 1987

By Warner B. D

Smelting at Mount Morgan started in 1906 with blast furnaces which were replaced by a reverberatory furnace in 1939. The second reverberatory, commissioned in 1944, was replaced by a copper flash smelter in 1972. Flotation concentrates, dried to 0.05 per cent moisture, were oxidised under accurately controlled conditions and produced 45 per cent Cu matte and a slag in the flash smelter. The matte was converted to blister copper and the slag was slowly cooled before grinding and retreatment in a flotation concentrator.

Jan 1, 1974

By Concha F, Sampaio R

In most of the literature, the hydrocyclone is viewed as a black box in which only global variables are present and where the equations are obtained by curve fitting. Recently some work has appeared where the Navier Stokes equations are solved numerically in the hydrocyclone geometry. However, in all of these works the air core surface, which has an important influence on the hydrocyclone dynamical behaviour, is modelled as being a cylindrical surface of fixed radius. In this work, we model the surface of the air core as a free-boundary which has to satisfy a jump condition, the Young-Laplace equation, relating the physics to the geometry. Based on this model, we are able to explain, qualitatively, some phenomena that have puzzled research workers in the field for many years, and can show, through the air core behaviour, the influence of material parameters on the performance of the hydrocyclone.

Jan 1, 1993

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 Runge IC

The mine planning process is reviewed and appropriate software considered in terms of "line process" or "support function". The mine planner's requirements of a geological model and the elements of and requirements of a computerised mine planning system are all discussed. The use of "support" software for mine planning is considered and general rules for its development are given. Important changes involved in implementing a computerised mine planning program are listed.

Jan 1, 1983

The mining industry was one of the first industry groups to be confronted by and to respond to public and government pressure to improve its environmental management. Companies operating in New Zealand and the parts of Australia with firmer environmental and planning controls responded quickly with environmental staff appointments to their development and operating arms. Even in less demanding jurisdictions in Western Australia and Papua New Guinea environmental staff were added to the payrolls. The issues then and now were seen as pollution related with land and water housekeeping leading to progressive or eventual site rehabilitation. Increasingly, however, environmental issues are being recognised as being more complex. They are about equity and social justice. Pollution of water, air or land is seen by the public as a question of personal and public rights, more or less wherever the pollution takes place, on public or private land. Environmental issues in mining have become caught up in the global perspective and a more holistic approach to environmental management. Environmental issues touch every comer of the community and action is being demanded. Nowhere is this better illustrated than on Bougainville Island where increasingly militant demands by land- owners for redress for environmental degradation from the Panguna Mine, on close examination, revealed many years of disenchant- ment with the government and the mining company over a wide range of social, cultural and environmental issues. Failure to address this satisfactorily eventually led to a bloody rebellion and finally an act of secession.

Jan 1, 1991

By C Fountain

It is commonly known that copper smelter terms include penalties if the concentrations of elements, such as arsenic, mercury and fluorine, exceed stipulated limits. It is less commonly known that the behaviour of these elements in the smelters can depend on the processes used to treat the concentrate. The principle behind the penalties is to compensate the smelters and refineries for additional costs caused by the presence of the penalty elements, but these costs will vary depending on the process used and the location of the smelter.The issues caused by the minor elements include effects on the occupational health of smelter workers, increased environmental disposal costs, increased operating costs and reduced cathode copper quality.The effects of minor elements can be surprising. High levels of arsenic in concentrate are considered undesirable, but some smelters add arsenic to anode copper to improve the performance of the refinery.Excess concentrations of some elements will result in rejection of concentrates by smelters. China has blanket import bans on copper concentrates with concentrations of lead, arsenic cadmium, fluorine and mercury exceeding specified levels.This paper will review the behaviour of minor elements in smelters and refineries, explaining the deleterious effects of each of them, to provide a greater understanding for people and organisations wishing to market copper concentrates.CITATION:Fountain, C, 2013. The whys and wherefores of penalty elements in copper concentrates, in Proceedings MetPlant 2013 , pp 502-518 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

By G Gibson

Realising that current roadway development performance levels were unlikely to sustain new generation high-capacity (15 Mt/a) longwall mines then being planned, the Australian Coal Association Research Program (ACARP) established a Roadway Development Task Group (RDTG) in 2005 to develop a research strategy targeted at improving roadway development performance in Australian longwall mines. The initial phase of the project identified a number of factors that differentiated best practice mines from others, and proposed a multi-faceted research strategy encompassing both short- and long-term research initiatives, including:conducting regular benchmarking studies across the industry to identify factors contributing to improved performance and to monitor performance trends,conducting regular industry roadway development operatorsÆ workshops to facilitate the transfer of successful roadway development improvement initiatives throughout the industry and facilitate networking between development practitioners,development of alternative skin reinforcement and containment measures that would eliminate the use of steel mesh and enable face support systems to be fully automated,development of automated bolting and mesh handling systems that would enable operators to be removed from the immediate face area,development of a body of knowledge of industry roadway development practice,development of a web-based information management system to capture and transfer emerging developments in roadway development practice and technology,reviewing the Australian civil tunnelling and underground metalliferous mining sectors to identify practices and technologies that could potentially be utilised to improve roadway development performance, anddeveloping a new generation high-capacity mining system capable of +10 metres per operating hour for 20 or more hours per day (CM2010). The paper reports on the progress of the above initiatives and outlines strategies to continue the pursuit for improved roadway development performance.

Jan 1, 2008

By D Craw

Middle and Late Cenozoic fluvial conglomerates and gravel in northeastern Southland record the transport of alluvial gold from Central Otago into Southland, and subsequent reworking and concentration of this gold into economic placer deposits. A corridor of geochemically distinctive, Hg-free gold derived ultimately from veins in Torlesse Terrane schist in Otago extends through the Caples Terrane and into Southland. The initial repository in Southland was fluvial sediment of the East Southland Group, specifically weakly auriferous, quartzose delta plain strata of the Gore Lignite Measures (GLM), a downstream equivalent of Dunstan Formation in Central Otago. Miocene uplift along the northwest trending Old Man Range beheaded the parent river system, isolating GLM from its Central Otago source area and establishing the proto-Waikaia River system. Rising topography between Otago and Southland increased fluvial gradients, and initiated erosion of cover strata and a sequence of tectonically induced gold recycling events. Auriferous GLM were recycled from the hinterland into broad braided fluvial channel and floodplain deposits of the Waikaia Group (new), specifically the highly auriferous Waikaka Quartz Gravels and equivalent Waimumu Quartz Gravels downstream (WQG), superimposing more proximal depositional environments over parts of the former GLM delta plain. WQG were deformed, and locally cannibalised during the later stages of their deposition by reverse movement on north-northeast trending faults of the Dunsdale System (NW side up). Increased tempo of uplift in the hinterland (Old Man, Garvie, Umbrella, and Blue Mountain Ranges) in the Pliocene and early Quaternary resulted in further reworking of GLM and WkQG from the hinterland as well as basement erosion. Progressively more basement-rich detritus was deposited as a locally auriferous piedmont (Gore Piedmont Gravels - GPG) over earlier channel and delta plain (GLM, WQG) strata, extending from the Blue Mountains to Waikaia, and southward through the Gore Gap to beyond Mataura. Southward propagation of the north-northeast trending ranges, local warping, and uplift of the Murihiku Terrane in Pliocene and Quaternary progressively deflected GPG fluvial systems and ultimately constrained them to the present valleys. Pre-existing auriferous strata (GLM, WQG, GPG) were reworked and deposited with or without basement detritus as these fluvial systems migrated toward their present positions. Auriferous remnants of these transitional deposits are preserved in local structural depressions on the uplifted blocks that deflected the systems (eg King Solomon Mine), and on locally abandoned floodplain segments on the lowlands (Pebbly Hills-Gore Gap). The present drainage has continued to incise and cannibalise its own and earlier deposits during late Pleistocene-Recent uplift to form confined channel placers within the present valleys.

Jan 1, 2002

MAXIMINE is a compiled, comprehensive, spreadsheet-based, macro- driven software package, written to aid in the rapid and early assessment and design of virtually any small, medium, and large mining or quarrying project. The system has been des

Jan 1, 1998

Selection of the mining method and most appropriate mine layout for deep open cut coal mines is discussed, giving particular attention to the types of mines expected to be developed in the future in Australia. Because of the more complex nature of these operations a large number of alternatives for mine design are available, and the constraints associated with these designs are discussed. Potential problems to be overcome are identified to allow setting of realistic targets for maximum output and build-up production rates.

Jan 1, 1981

In 1975 the US Bureau of Mines (BOM) under contract with the Bureau of Indian Affairs (BIA), began a systematic mineral resource evaluation of Indian reservations in the United States. The purpose of the BIA/BOM program was to stimulate economic development on Indian lands through exploration and mining ventures with the mining industry. Since that time, 109 phase I reports (literature studies) and nearly 45 phase II and phase III (field studies) reports have been written by the BOM. The various tribes in conjunction with the BIA have access to these reports for decision making regarding mineral resource development.

Jan 1, 1990

The detailed engineering of a coal preparation plant is important from the point of view of optimum constructibility, operational security, ease of maintenance, operating costs, meeting environmental goals, safety, plant housekeeping and reduced corrosion and erosion. This paper reviews the several large coking coal preparation plants engineered by Fluor Australia in the past 10 years, and changes and trends apparent for detailed engineering of future plants. Areas of engineering to be covered are coal feed preparation, conveyor design, plant layout, electrics and instrumentation, noise attenuation, erosion and corrosion protection, magnetite handling, rejects and tailings disposal and coal stockpiling and blending.

Jan 1, 1982

A universal grinding circuit model suitable for an arbitrary structure of flowsheet has been suggested. In this model classifiers and mills are described in a most general form. What puts the model in a class by itself is the automatic mass balancing in all streams of the circuit. In order to provide this a special classifier model is adopted. A previously published continuous steady state process model is used as a grinding model. Non-linearity of classifier model leads to a resultant circuit model which is equivalent to a non-linear integral equation. It complicates somewhat calculation algorithm in comparison to that of linear model, but provides a physically meaningful solution.

Jan 1, 1993

Modern Management Systems for Higher Margins By Malcolm Roberts, Catalyst for Corporate Performance Ltd Malcolm Roberts put the case for changing systems in order to change behaviours and attitudes and improve productivity. ""The key to lifting margins is changing systems."" A system is anything that drives ways of doing things. Sometimes these are formal, and documented, and sometimes they are not. Improving productivity The way to dramatically improve performance is to use the systems. Roberts stressed that if systems and processes are under control, the benefits of automation are huge. If they are not, the benefit of automation will be lost. To improve productivity, you need to: ò identify what to change in the process, ò use the proven methodology to systematically improve the process, and ò change what people do - change work practices.

Jan 1, 1997