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Measurable physical characteristics of placer deposits include both fluvial sedimentological features and their related heavy mineral suite. These two important identifiable factors are interrelated and generally compliment each other furnishing a complete geological geochemical tool in cost- effective placer evaluation. Heavy mineral suite composition and character will change downstream from the provenance area and will compliment the related sedimento logical environment. Careful attention to gold particle characterization during the exploration phase will indicate new source additions, enhance deposit evaluation techniques and greatly assist in maximizing metallurgical efficiencies. Recognition of the various characteristics within these fluvial systems should enhance the total contained geochemical suite evaluation considering a finite source. Failure to recognize and measure these two important features very frequently leads to frustrated and unrewarding placer evaluation objectives.

Jan 1, 1986

The authors have succeeded in providing additional rigour and clarity to the formulation and execution of the dynamic programming algorithm for optimum open pit limit determination. The inclusion of the blocks on the J + 1 column in the search for Pmax, and constraining this search with blocks assigned a value of negative infinity, ensures an optimal solution within the defmed blocks. The effect of the negative infmity blocks is to preclude mining along the diagonal blocks from the first row that they occur in. Figure 1 graphically illustrates the effects of this on the calculation of P. A practical application for constraining mining with negative infmity blocks is the case where the pit outline is defined by lease boundaries and not by the value of blocks to be removed. Any legal, social or physical constraint could be accounted for in the same way.The danger in applying this technique is that the negative infinity blocks will override any other more profitable solutions that may exist. This is in fact what has happened in the example that the authors use. If a further column is added to the left hand side (column -1) and the calculation is carried out again, a more optimal x-section can be found. (If the negative infinity values are removed the same result is obtained.) This gives a pit value of 112 as against the 108 of the authors' optimal pit. This calculation is shown in Figure 2. Lerchs-Grossman optimization is reliable only if there are sufficient columns available to allow "mining" to optimum depth of the ore body and still allow the pit to break out at the surface within the confines of the columns.This author's approach is to create enough columns each side of the lateral limits of the ore to allow the pit to intersect the surface while still within the confines of the block model. Implementing the methods discussed by the authors helps to reduce the number of columns required to achieve this.

Jan 1, 1987

With the recent collapse in commodity prices the size and number of resources project has diminished markedly in recent years. Coupled with the disappearance of the "open cheque book approach", this has led to a revival of the lump sum or turn key project. The key features of this mode of development are compared with the "owner managed" and "reimbursable cost plus fee" alternatives - with respect to schedule, cost and quality control. Key facts for the successful implem- entation of this mode of development are identified. However, the approach is not advocated for all projects and the potential shortfalls are also identified.

Jan 1, 1986

By Burchell S, McGregor K

The process of design, measurement and review is essential if blasting is to continuously improve to meet the increasing productivity goals of most mining operations. To achieve continual improvements, many operators are turning to contractors to provide the necessary technology. Under this arrangement, the contractor becomes the supplier of a service rather than products and assumes some of the risks associated with blasting by guaranteeing the end result. If contractors are to obtain significant productivity improvements they must continuously improve every aspect of their business.

Jan 1, 1994

Deformation of the lithosphere by tectonic forces is investigated from both observational and theoretical standpoints. Global and regional geophysical data bases, coupled with the means for their rapid display and analysis, facilitate recognition of areas of the con- tinents and oceans where the response of the lithosphere to these deforming processes might fruitfully be studied. Gravity anomalies, from Seasat altimeter data and from land and shipboard measurements, provide critical infor- mation on the isostatic state of deformed lithosphere and therefore on its thermal and mechanical properties.

Jan 1, 1987

Sasol Roche Blasting Services (SRBS) and its former owners have been in the process of developing and utilising low-density explosives over the last ten years. Many blasts have been fired in varying strata types in a number of mining operations. This has led to a good understanding of the product and the best methods to exploit its characteristics when designing blasts. Unlike some other low-density products, SoftLOAD« is a homogeneous mix that is easily handled and able to be loaded at high load rates. This paper discusses the physics of SoftLOAD« low-density explosives and how through correct utilisation, blasting outcomes can be significantly improved. It also touches on the various side benefits that can provide the blast designer with a more controlled blast.

Jan 1, 2004

Petroleum exploration and development is vitally important for the future well being of Australia. The Australian petroleum exploration/development industry is alive but not so well. A combination of.:factors point to the industry requiring a much more mature effort in both short and longer-term planning to ensure greater success and effectiveness for petroleum discoveries and development. While many petroleum exploration companies are competently run, there are far too many which will be lucky to survive, even though their exploration areas are highly Prospective.

Jan 1, 1983

A proved routine mapping practice is described involving detailed observations on grade and structure. The equipment and methods employed are giving good service under the conditions encountered. Stopes are mapped on every floor whether timbered or open, "Kodatrace" workplans and sections being used, and in addition all development whether in country or lode is mapped.INTRODUCTIONThe accumulation of geological data for application to current mining problems and to the search for new ore involves the necessity for close mapping of all available underground faces and backs. The technique which has been developed to suit conditions at the North and British mines of North Broken Hill Limited forms the subject of...

Jan 1, 1940

During the last 20 years, manufacturers of Australian iron have given increasing attention to development of external markets for processed blast furnace slag. Slag has been in widespread use overseas and data on the performance of Australian slag in concrete lave shown it is suitable for that use. Chemical and physical properties of typical Australian slag products including air cooled, granulated and pelletised slag are discussed and compared with local natural aggregates. Special attention is given to pumping achieve- ments with slag concretes and the observed durability of concrete after many years service. More'recent applications for granulated slag as a sand replacement are discussed. It is concluded that'whilst more wide- spread use of slag is possible, the cost of marketing and transporting slag are likely to restrict opportunities unless for local usage.

Jan 1, 1979

By Warren R. P

When the original Mount Gunson joint venture, between CSR and United Uranium ceased operations in December 1971, an intensive ex- ploration campaign was launched to prospect for more ore in the Mount Gunson region. This campaign resulted in the discovery of the Cattle Grid deposit. A comprehensive sampling programme proved the existence of 4.6 million tonnes of ore, at a mean grade of 2.4% Cu, calculated at a 1.0% Cu cut-off. The planning and development programme that followed this discovery included not only the mining and metallurgical aspects of the exploration of the deposit, but also the en- vironmental aspects. Preliminary work included data collection with respect to meteorology, soil types, and existing flora and fauna.

Jan 1, 1976

The present-day arrangement of old ( ? ) Palaeozoic and Mesozoic metamorphic rocks in eastern New Guinea lends some support to the concept of tens:konal dilation in Upper Cretaceous to Lower Tertiary time, It appears that the metamorphic core of the Morobe Arc (Glaessner, 1950) could have been rifted from the eastern flank of Cape York Peninsula, and then been carried north-eastward by some unspecified sub-crustal. tangential force. In the early stages of the rift it is thought.that submarine basalts may have extruded up the .'tension .scar and spread across the floor of the opening rift. Thick clastic muddy sediments derived almost exclusively from the rifted block were then spread across the floor of the opening rift. Later ~ertiary lateral movements from east to west along the Markham-Ramu Fault appear to have bent the northern end of the Morobe Arc towards the.east,,causing the intense folding in the sediments of the Aure Trough.

Jan 1, 1962

Pajingo Gold Mine Pty. Ltd. is a subsidiary of its United States of America parent the Battle Mountain Gold Company. Battle Mountain Gold Company was created in August 1985 as a spin-off of the United States of America Pennzoil Company's gold interests.Pajingo Gold Mine Pty. Ltd. currently has its headquarters and base for operations located in Townsville, Queensland. The Company's main current activities are the exploration and evaluation of the Pajingo Gold Property situated some 50 kilometres south-east of Charters Towers and in the northern Drummond Basin.The discovery of the Pajingo gold mineralisation by the Company was the indirect result of a regional program established to evaluate Carboniferous age volcanic plugs in north Queensland for gold mineralisation.

Jan 1, 1986

The optimum plant capacity for a new mine is usually based on empirical studies or ærules of thumbÆ, subject to confirmation by detailed scheduling of the proposed mining operation. The mining industry has a record of poor returns on investment and a high rate of project failure using these methods, with under-performance in grade being a common experience. The assumption that æeconomies of scaleÆ will result from increasing throughput rates needs to be balanced by an awareness of the adverse effects of increasing the rate beyond a level that issupportable by the resource. For each scale of operation considered, it is a reality that for any intended head grade, at the associated intended cut-off grade, the actual head grade achieved will fall as the mining rate increases. This effect is known to people at operations but is not recognised in current ore reserve estimation methodology. Once recognised, this dependency of head grade on mining rate can be quantified and used to establish the economically optimum mining and processing rate for a new project. A simple analysis is proposed, which may be extended to detailed spreadsheet modelling for financialoptimisation.

Jan 1, 2002

Separation in magnetic fluids is one of the modern techniques that offer a unique approach to material manipulation in a broad spectrum of industries. Its wide-scale application has been restricted so far for a variety of reasons, including limited throughput, inefficient recovery of magnetic fluids and the cost of commercially available magnetic fluids. This situation has changed recently. Very selective separators, with automated density control, capable of treating a variety of materials in a wide spectrum of densities and particle sizes have been built by DebTech and applied in the diamond industry. Technology for the recovery of magnetic fluids has been developed and low-cost magnetic fluids, with high magnetisation and low viscosity are being produced on a production scale. Scale-up of the technology has been addressed and units capable of treating large tonnages of material have been designed. Such a development thus offers the minerals industry a technology that surpasses the existing technologies in selectivity, efficiency and versatility

Jan 1, 2000

Mathematical economic models for assess ment of technological progress in the mining industry in the USSR are discussed. The models are based on a simple index, TT which approxi- mates the rate of growth of the people's living standards. However, for application in the mining industry it is necessary to incorporate various parameters to account for the dynamic charges in the geological, mining and other technological conditions. Derivations of the models are shown and examples of results are Included.

Jan 1, 1977

It is well known that in most areas of Central Europe it is not difficult to find water - usually at shallow depths - and to recover and use this water. What is much more difficult, however, is to find water sources that offer both sufficient in quantity and qual- ity. Far too often, there are sources that offer abundant quantities but of poor quality or vice versa, i.e. high quality water but insufficient volumes. In the former case where water quality is not adequate - which is more often than not due to anthropogenic factors and only very rarely a result of geogenic effects - the application of treatment techniques can help to turn such water into potable water that is suitable for human con sumption.

Jan 1, 1988

Past and present developments in the use of blast furnace slag in the manufacture of glass are outlined. The crude slag from Port Kembla is beneficiated by the Mineral Resources Division of Australian Consolidated Industries Ltd. at Mascot using a dry magnetic separation process which reduces the iron level in the slag to an acceptable value, The chemical and physical properties of both the crude and beneficiated slag are given and compared with those of other slags used in the manufacture of glass. Slag is added to intro- duce alumina into the glass and its addition to the glass batch also results in faster melting and refining. Slag was first used in Australia in 1968 and its use has increased steadily year by year. At present about 16 000 tonnes of slag are used per year, mainly in amber and white glass. Beneficiated slag is used'in three plants to supply all the alumina required in the amber glass and in four plants to supply part of the alumina required in the white glass, the amount added depending on the acceptable iron level in the glass. Slag is also used in limited quantities in the manufacture of both dark and light green glass.

Jan 1, 1979

By Sehic OA

One aim of testwork and flowsheet development is to ultimately provide a reliable and flexible plant that is simple to operate and maintain. Testwork can indicate amenability of ores to CIP treatment and provide a basis for process design and economic appraisal. Batch cyanidation and CIP tests are often sufficient for small projects. Continuous multistage test rigs can be operated to simulate plant operation and to provide data for flowsheet optimisation. Operating requirements, gold recoveries and potential problem areas can be anticipated at an early stage with more confidence. Subsequent project development involving decisions on the basic flowsheet, equipment types and general plant arrangements are based on practical considerations and experience. Computer aided process modeling and economic appraisal can be useful in analysing various tradeoffs, firming up the flowsheet and equipment sizes, and in specifying operating targets for the future CIP plant. INTRODUCTION Carbon-in-pulp (CIP) technology which has developed rapidly since 1974 is now accepted as an economically and technically viable process for the efficient recovery of gold. This paper describes testwork and flowsheet development procedures used for CIP evaluation and design.

Jan 1, 1982

THOSE who dabble in m.ining are no exception to the general rule that persons who know a little of a subject are apt to think that they know all about it. Some colour may be lent to the belief that anyone may succeed in mining when we hear stories ofsuccessful diggers and others who have accidentally dropped on to something good through no foresight on their part; but we seldom hear the contra account of the far larger number who fail. Those who go more thoroughly into the subject, and take up mining as a profession, know very well that it is not one that can be carried out successfully by rule of thumb, but when they point this out to the public they are credited with trying to make it a closed profession; and outsiders are for ever trying to find out the 'trade secrets,' at the same time spurning the main one, which is hard study, experience, and the ability to apply their knowledge.The average mining man is not rich. When he amasses a fortune it is generally through speculation rather than professional work, thought no doubt his technical knowledge may have assisted him. However, making a fortune and running a mine are twodifferent things.

Jan 1, 1911

IN the course of his employment the Broken Hill Co. the writer has had occasion to use and instruct others in the use of the Shamrock rescue apparatus. This paper deals with the various types of apparatus tested. The common object of the various types of breathing apparatus is to enable the wearer to remain and work for varying periods of time in an atmosphere which is either deficient in oxygen or is poisonous that is, contains carbon monoxide or irritating and irrespirable vapours, such as the smoke from underground fires, sulphur dioxide or ammonia fumes. For any apparatus to be efficient as required in the above paragraph it must fulfil the following conditions;1. Air-tight as regards the passage of the air from the outside to the inside. In atmosphere containing carbon dioxide a slight leak would not render the apparatus useless; but where irritating vapours, such as the smoke from burning oregon and sulphides, are met with, even the slightest leak must be avoided.2. The oxygen supply must be ample, and so supplied that it is not checked by expiration.3. Expiration and inspiration must not be retarded.

Jan 1, 1911