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By Waddell S

A new procedure has been developed for the direct determination of metals loaded on activated carbon. It involves preparation of a suspension of the powdered carbon in water, followed by direct sampling of the suspension with a micropipette,and analyses by atomic absorption spectroscopy using carbon rod atomization. Advantages of the method include the simplicity of sample preparation and the ability to provide a complete metal analysis in 1 - 2 hours. This enables carbon-in-pulp operators to respond quickly to changes in plant efficiency arising from carbon fouling. The successful application of the method has been demonstrated for gold, copper, nickel and iron. Other elements to be surveyed include calcium, magnesium and silicon.

Jan 1, 1984

The Broken Hill orebodies have 'traditionally been mined by cut and fill trethods. In the mid-1950's New Broken Hill Consolidated Limited experimented with sublevel longhole open stoping but did not pursue the method due to inefficient loading and poor fragmentation. The introduction of longhole open stoping in 1968 was a radical change and was necessary to enable the profitable extraction of lower grade orebodies and this method is now used for 55% of the production from The Zinc Corporation, Limited and New Broken Hill Consolidated Limited mines.

Jan 1, 1982

By R M. Papini, A C. Araujo, A E. C Per

Flotation is an important process used in the concentration of iron ores. One of the challenges for process engineers is the low metallurgical recovery associated mainly with the fines fraction. In this work, the use of synthetic flocculants in iron ore reverse cationic flotation was investigated. The flocculants utilised were polyacrylamides of high molecular weight and different ionic degrees. Bench scale flotation tests were performed to compare the flotation performance with and without addition of polyacrylamides. It was observed that cationic and non-ionic polyacrylamides cause a significant increase in the metallurgical recovery. The anionic flocculant did not improve the flotation performance. An adverse effect was a slight increase in the silica content of the concentrate. Flotation with polyacrylamides was influenced by the hydrodynamic conditions of the pulp, such as agitation and the weight percentage of solids in the flocculant conditioning and flotation stages.

Jan 1, 2005

Increases in mechanisation and mining at greater depths are leading to additional problems of heat and humidity in many mines. As a result there is now an escalating demand for temperature prediction simulations appli- cable to underground environments. After a brief review of the present situation with regard to world mining and the use of environmental programs, the paper goes on to discuss in moderate detail the mathe- matical modelling of the many parameters that govern the condition of the ventilating air in a mine. The development of a program that gives the temperature distribution for a mine ventilation system is then outlined. The practicality of the program is discussed and the presentation format for users is explained. Simplification of input data requirements and the acquisition of data from other planning programs are an integral part of the commercial application of this program.

Jan 1, 1977

By Seshold P

The cost of capital is the rate at which a project's cash flow should be discounted to obtain the Net Present Value. The cost of capital is a weighted average of both debt and equity funds of a company, on an after tax basis. Two methods are described for calculating a company's cost of equity, the Dividend Valu- ation Model and, more importantly, the Capital Asset Pricing Model. A worked example is presented where the cost of capital was obtain- ed for two resource companies. The application of the cost of capital was illustrated by way of a mining equipment replacement problem. The paper outlines refinements and problems that may be encountered with the use of the cost of capital, and concludes that it is an integral part of any project evaluation.

Jan 1, 1983

Stress Mapping Technology is aproprietary technique developed to target epigenetic mineralisation located in dilatant (low stress) sites. It is a computer based technique, based on rock mechanics principles and stress-strain relationships, which seeks to transform strain data, in the form of a solid geology map, to stress data.The main assumptions in the conceptual model are that:The strain pattern of faults and lithological contacts have not been changed since mineralisation i.e. that ore formation is late in the structural history.Stress orientations and magnitudes are known.Rheological properties of faults and rock units can be deduced.The 2D geometric and rheological data is then treated by a mathematical technique which permits the geometry of the elements to be defined by the spacing and orientation of the discontinuities in the rock mass.

Jan 1, 1990

Mount Isa Mines operates Hewlett Packard 1000 computer systems for process control in its major mineral processing plants. To simplify control systems implementation, a process control software package has been developed. This package is now used at the Lead/Zinc Concentrator where the HP computer is interfaced to Foxboro Interspec/Spec 200 system and Honeywell TDC 2000 front-ends. The HP computer controls crushing, grinding, flotation and tailings disposal. This paper outlines the development of process control systems at Mount Isa Mines. The creation of the process control package is described and the reasons for its development highlighted. The application of the software package and the implementation of process control systems at the Lead/Zinc Concentrator is detailed.

Jan 1, 1978

Despite extensive oil exploration in"Western Australia over the past 12 years no commercial oil fields have yet been found. A total ' of 66 test wells have been drilled throughout the State but only Rough Range No.s.. 1 and 1A have produced oil in significant quantities. Active oil exploration is now in progress in the" Canning, Carnarvon, Perth, Bonaparte Gulf and Officer Basins. Test wells have been drilled' in ,all of these except the Officer Basin, where the subsurface stratigraphy is still unknown. Large .areas of the other four have hot yet been drilled. It, is- probable that. commercial oil deposits will eventually be found' in these basins as they contain thick marine sequences, and have structures 'suitable for.,the. entrapment of oil. .

Jan 1, 1964

Although the title of this paper permits a very broad scope for discussion, I propose to deal mainly with those aspects of design part- icularly related to rook filling, the'theme of this conference. The unique suitability of belt conveyors for the continuous economical delivery of materials into or out of underground workings, is well established and needs no elaboration. The facility with which conveyor units, comprised of modern modular components, can be adjusted to lengthen or shorten, their ability to be readily repositioned to suit the develop- ment of a work pattern and their virtues as low noise, reliable transport media, are already accepted by all who are involved with the mining industry.

Jan 1, 1973

Clearly visible in geophysics is a trend away from simply finding and drilling anomalies obtained with off-the-shelf equipment, condes- cendingly sold by travelling salesmen. Instead, technical tools are becoming available which allow us to choose or design equipment and sur- vey procedures for the specific problem at hand. The advent of micro- and smaller computers enable us to collect more and better measure- ments and to rapidly process them so as to emphasize the features which are being sought. These new capabilities have important consequ- ences both to the extent to which geophysical tools will be applied in the industry, and to the skills which will be demanded of those using them. Because of its uniquely difficult exploration problems, Australia must expect to amplify its new prominence in the development of mining geophysical technology.

Jan 1, 1981

The Court rejected the suggestion that CRAE had actively misled DMR concerning the worth of its tenements. The Court agreed that CRAE remained silent about certain significant information concerning CRAE's own tenement area. It was a significant question as to what duties CRAE'was under, given that it was in joint venture with DMR in respect of one of the tenement areas. Did that joint venture create an obligation on CRAE to disclose everything it knew? The Court said no. The Court said that the fiduciary duties were defined by the terms of the farm-in agreement between DMR and CRAE. When the Court examined the disclosure obligations within the confines of the contract, it held that CRAE had not breached those terms.

Jan 1, 1990

By Q Xin, X Shengming, C RuÆan, Z Zhigeng a

The optimum defluorinating conditions for Sichuan bastnasite crude ore were determined by orthogonal experiments. Over 95 per cent fluorine in the crude ore was stripped by roasting 30 minutes of the crude ore with Na2CO3/ore =0.25 at 650oC. The stripped fluorine crude ore was further treated by NH4 Cl to recover rare earth. Above 95 per cent rare earth can be leached by water after the stripped fluorine crude ore mixed NH4Cl(NH4Cl/ore =1:1) roasted 1 h at 325oC. At the same time, the rare earth leaching solution contains little Fe, Si and Al. Therefore it is propitious to further purify the solution and recover rare earth.

Jan 1, 2000

The passage of a vast array of new State and Federal environmental legislation over the last couple of years has required many mine operators to sharpen their focus on environmental requirements. Established requirements, such as environmental impact assessment, minimising disturbance and rehabilitation must now be complemented by mine environmental management plans. These may not only require regular monitoring of mine operations and detailed forward planning to prevent or reduce environmental harm caused during mine operation, but annual updating. It is likely that in future these plans will be required to incorporate general principles such as pollution prevention, sustainable development, waste minimisation and conservation of biodiversity and ecological integrity.

Jan 1, 1993

By J Ralston, R Sedev, D Fornasiero

The foam behaviour of low molecular weight polypropylene glycols (PPG) was investigated as a function of concentration and molecular weight (190 - 2000 g mol-1). For each polypropylene glycol, foam stability increases with concentration and passes through a maximum, beyond which foamability is suppressed as the solubility limit of the glycol is exceeded and droplets of glycol form. Light scattering data as well as static and dynamic surface tension results provide the key information leading to these interpretations. A maximum in foamability was observed for the PPG molecules with increasing molecular weight (caused by a change in molecular conformation at the interface). This suppresses the Marangoni effect and leads to a decrease in foam stability.

Jan 1, 2005

It is argued, that plate convergence, i.e. subduction, at other than right angles under a continental margin may lead to compensa-tional transcurrent faulting in the sialic environment. In this pro-cess the introduction of ultrabasic slivers, derived from the down-going oceanic crusial plate, along this fault may occur. This regi-me, both compressive overall and tensional along the transcurrent fault, will contain numerous indications for ongoing igneous and tectonic processes (such as volcanism, hot springs and frequent earthquakes).Examples for this scenario are California, the hinge between the Alpine- and Appennine orogens and the island of Sumatra.Igneous manifestations of subduction will be present both as inter-mediate intrusions and/or andesitic piles. The intermediate volca-nics may be intensely altered (chloritic, propylitic, argillic). Silice-ous breccias and banded chalcedonic sinters may be commonly found. This entire scenario is indicative for epithermal gold mine-ralisation.

Jan 1, 1990

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

This paper will examine some of the significant developments in the training field in Australia in the past decade and the application of these changes to the mining industry generally, and the coal sector specifically. Three major aspects will be examined:1. Competency - the use of Industry Competency Standards and how these can be used for achieving enterprise performance requirements2. Assessment - making judgements about an individual's competence, and using a rigorous assessment system as the basis for the "authorisation" system at a mine3. Evaluation - ways to evaluate the return on investment in training, and convincing CEO's/shareholders that your training dollar is being spent wisely.Before examining these issues, it is important to understand the drivers of change in the training systems in Australia, and the functions that Industry Training Advisory Bodies (ITABs) perform.

Jan 1, 1998

This paper addresses the unique environ- mental programmes which prevail at Ranger and their importance in the future profitability, of Ranger Uranium Mines Pty Ltd. (RUM) Industrial relations, general safety, and occupational health have long been regarded as part and parcel of the concept to 'manage for profits'. More recently, the need for environmental protection has also become an important management consideration. This is particularly so at the Ranger Uranium Mine where environmental protection is very closely and continuously regulated. Since the commencement of operations at Ranger some three years ago the company has operated within these regulations and demonstrated clearly that yellowcake can be produced efficiently, economically and safely. The company also recognises that in order to ensure continuity of production, it will have to continue to operate within these strictly supervised Regulations.

Jan 1, 1984

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