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The light microscopic study of the physical structures of coal and associated mineral matter is an important technique in providing information on the characterisitics and possible behaviour of coals in industrial processes. However the ultrafine nature of coal and mineral particles together with the limits of resolution of the light microscope restrict such studies. Scanning electron microscopy (SEM)with its better resolution and higher magnifications is the means by which further information on coal properties can be obtained. An associated energy dispersive X-ray specrometry (EDS) method allows non-destructive in-situ chemical analyses to be carried out at the same time.

Jan 1, 1989

A Presidential Commission of Enquiry into the conservation of South Africa's coal resources was appointed in 1970. This Commission, in co-operation with the Chamber of Mines of South Africa, established a national inventory of South Africa's in situ and extractable resources and reserves of coal of various types and grades by several mining methods. South Africa's future demand for coal by all market sectors and the specifications of coal required, were also established by means of econometric models. A comparison of potential supply and anticipated demand indicated serious defi- ciencies of certain types of coal and the need for the conservation of others. This paper describes recommendations for alternate strategies for the optimum utilization of available resources. Con- sideration was given to various policies relating to pricing, exports, taxation and incentives, and to the possibility of the substitution of higher grades of coal by lower grades. The steps so far taken to develop a national coal policy in South Africa are described.

Jan 1, 1977

By Netchaef P

A rationale is presented for the use of vegetation on mine dumps to minimise runoff and infiltration which become vehicles for potential pollution. The unique topography of mine dumps promotes high atmospheric advection which leads to extraordinary energy levels for evaporation discharge - the driving force of vegetation "pumps". This effectiveness is mainly a function of how well the vegetation will grow on a given site. Recent advances in technology allow water discharge by vegetation to be measured semi-automatically, accurately and cost effectively. As a result the basis now exists for a thorough evaluation of the optimum mine dump vegetation cover. This paper presents the current status of dump rehabilitation as seen by the mining industry. The significant prospects for use of vegetation to minimise mine water related problems with subsequent savings in capital and operational cost are also outlined. However, to examine the crucial questions of optimum hydrological ability, suitability and cost effectiveness of various types of dump vegetation a proposition is made to interested parties in the mining industry: The CSIRO needs potential study sites to evaluate the hydrological ability of vegetation under mine dump conditions.

Jan 1, 1988

By Fewings JH

When the mining and milling of 1100 Copper Orebody commenced, difficulties were experienced in producing a satisfactory grade of copper concentrate. The major concentrate contaminants were fine pyrite and silica, particularly in the minus 10 microns fraction. Studies of the 1100 Orebody showed that much of the fine grained pyrite and a proportion of the silica present in the ore contained carbonaceous matter in the form of complete or partial rims and as internal carbon films disseminated throughout grains. The hydrophobic surface property of the carbonaceous material resulted in an inherently flotable fine pyrite and silica fraction. The addition of a 60:40 mixture of nigrosine and dextrine, initially to a prefloat concentrate of the inherently flotable carbonaceous material and finally to'the total copper flotation feed, successfully controlled the flotation rates of the carbonaceous pyrite and silica. The objective of a 25 per cent Cu concentrate grade was then achieved without decreasing copper recovery.

Jan 1, 1970

The economic future of the Palmer Goldfield lies with both the gold mining and the tourist industries. An equitable solution to the competition between the two involves putting a dollar value on the historical evidence there for our Australian heritage.On 23 October 1986 the Queensland Government gazetted the Palmer River Reserves R16 of 16 200 hectares, in recognition of the competing land uses emerging in the region. The intention is that historically significant gold mining sites and relics will be preserved in situ with provision for continued gold exploration and mining.This paper explores and explains the administrative process of achieving a set of Management Guidelines for Rl6 within the Queensland political milieu. The result of that process is the achievement of some of the highest preservation standards in Australia, prohibiting surface disturbance of defined Category 1 sites, and no mining proposal has yet been refused approval.The Palmer Goldfield R16 experience is a major step in achieving a co-ordinated approach to both current mining and preservation of Queensland's mining heritage.

Jan 1, 1990

The main iron ore deposits of Western Australia fall into three very different geological classes, which are, in order of importance: hematite enrichment ore, pisolitic limonite ore, and sedimentary ore. These are presently (1973) being mined in the approximate proportions 20 : 2 : 1, while the equivalent proportions for reserves are, very approximately, 200 : 70 : 1. Two minor categories which mar- ginally qualify as ore are detrital material variously referred to as scree ore or canga, and potentially beneficiable iron formation. These two latter types are dealt with very briefly, and the three main categories are dis- cussed in order of economic significance. Hematite enrichment ore results from the selective replacement of a pre-existing host rock by hematite. Almost without exception, this host is cherty banded iron formation (BIF); but certain exceptions have great genetic inter- est. Ore bodies of this kind occur both in the Archaean BIFs of the Pilbara and Yilgarn Blocks and in the Proterozoic BIFs of'the Hamersley Basin. It follows from their virtual restriction to a single kind of sedimentary host that there is strong stratigraphic control over the shape of ore bodies: these may be almost flat, of dyke-like form, or of complex configuration, according to the pre-enrichment structure of the host bed. This structure was an important control over the position in which ore formed:

Jan 1, 1973

By Parer W. R

During the last fifteen years there has been a marked change in the demand and supply patterns of coking coal. The world demand, predominantly Japan, has increased from 23 million tonnes of world export/import coal in 1960 to an expected total of at least 100 million tonnes by 1975. In the last ten years Australia has been the main beneficiary in the growth of the export coal trade. This has been brought about by its proximity to Japan and its large econ- omically mineable reserves of coking coal. A feature of the recent coal development in Australia has been the requirement of companies in new areas to provide massive capital for infrastructure costs. The ability of the Australian coal industry to retain a large share of the world export market depends to a large extent on reasonable costs to transport coal from mine to the market place. In some areas of Australia this means that railway lines, loading and unloading facilities, and ports will have to be up-dated at substantial costs. On the long haul to Europe the recent increases in the prices of bunker fuel have made the price of coal less competitive when compared with sources

Jan 1, 1974

Since its beginning, with the works of D. Krige and later, G. Matheron, geostatistics has been analyzing in detail the essential factors at play in ore reserves estimation problems, with the ever-present aim of an optimal use of the available information. Not only do the reserves depend on the geological in situ resources, they also require a correct appraisal of many technical and economical parameters. The objective of the present paper is to show how the method of technical parameterization of reserves, which is at the heart of the geostatistical approach, provides an extremely powerful and versatile tool for characterizing a mining project. After a review of the main properties of the technique, its use in the economic optimization of a project will be examined. Two examples from copper and gold deposits will be given.

Jan 1, 1987

By W J. Rankin

A study of refined metallic copper and nickel production was carried out using Life Cycle Assessment methodology to estimate the life cycle emissions of greenhouse and acid rain gases for these metals using data derived from the literature. Various processing routes were investigated which included a pyrometallurgical and a hydrometallurgical route for each metal. The effect of a number of process variables, namely ore grade, fuel type for electricity generation and efficiency of generation were also examined in the study. The results of the study, expressed in terms of total (or full cycle) energy consumption, Global Warming Potential (GWP) and Acidification Potential (AP), showed that the hydrometallurgical processes involving solvent extraction and electrowinning had higher energy consumptions and GWPs than the pyrometallurgical processes for both metals. Nickel metal production was shown to be several-fold more energy intensive than copper metal production. The significant effect that falling ore grades have on attempts to meet greenhouse emission targets was also highlighted in the study.

Jan 1, 2000

The treatment meIhods selected for the concentrator at Cobar Mines Pty. Ltd. called for a high degree of automatic control of both the grinding and flotation sections.The resulting concentrator layout includes a central control room overlooking both grinding and flotation sections. The control room houses process recorders, controllers, and indicators. together with motor stopstart stations and alarms.Plant instrumentation includes load cells and variable speed hydraulic drive feeders for feed-rate control of autogenous mills, together with nuclear density gauges, differential flow transmitters, and pneumatic control valves for water and pulp density control.Flotation cell pulp levels are controlled by floats and pneumatic actuators; flotation reagent controls include magnetic flowmeters and time-operated solenoid valves.

Jan 1, 1969

A zone rich in-fish debris in the Rolling Dow= Group in the sub-surface of the Great-Artesian Basin has been discovered a Further research has shoe i this zone to-be of very wide distribution in the Artesian Basin and to occur. at the base of the Ta?nbo .f ormati'on resting on the Roma forma-tion. The zone gives a very characteristic curve on the electric and' gamma ray logs and is thus an excellent correlation marker in the sub-surface over a very wide area. It is probably to be correlated sith.the Toolebuc member described from: outcrops east of Boulia. There .are apparent similarities between the Fishecale zone of the Great Artesian Basin in' Australia and the Fishscale sand of the Western Canada Sedimentary Basin.

Jan 1, 1962

The behavior of a curved wall under earth pressures for a horseshoe shaped tunnel lining is considered to be closely related to the beha vior of a vertical beam with variable flexural sti-"ness on an elastic foundation. In stress analysis an approximate method which divides the axis of the tunnel lining into small finite lengths and replaces the integrals by summation is usually adopted. this method is extremely complicated and tedious. However the variations of the moment of inertia from point to point along the wall axis can be expressed by a power function inversely .eith the distance from the ll )ottom and the analytical method can still used. The equations for the calculation of deflection, rotation, bending moment, shearing urce, and soil reaction of the curved wall are derived in nondimensional forms in this paper.

Jan 1, 1987

By Thompson J

A programme of testing and evaluation has been in progress at Isa Mine for the last four years with the objectives of rationalising ground support practices, improving installation quality and increasing productivity of ground support functions.Numerous innovations have been successfully implemented. These include the introduction of swellex rockbolts as the major form of temporary support, the use of splitset rockbolts as the primary means of support for the hangingwalls of cut and fill stopes and the introduction of dowels with pumped cement for general long term support.The installation of swellex bolts has been successfully mechanised throughout the mine using Tamrock automatic rockbolters and Atlas Copco BUK 11R drilling rigs modified for this purpose.

Jan 1, 1985

Natural gas was introduced to the Melbourne reticulation system in April 1969 and since that date sales to industrial consumers in the Gas & Fuel Corporation of Victoria area of supply, have increased by over 50% This increase has occurred despite the fact that the areas in which the new fuel is available have been dependent on the progress of the conversion operation from manufactured gas. The half way mark for conversion was reached in May 1970. The reason for the adoption of natural gas by industrial users is usually the result of objective financial analysis leading to the conclusion that the new fuel will give the lowest overall production cost. Many factors are involved in such an analysis of which the price of the fuel is only one. Amongst other important elements in the cost calculation are:- -ò òò -(1) The effect of fuel on product quality (2) Maintenance and handling costs for alternative fuel. In addition to economic gains for the individual user, the use of natural gas should benefit the whole community through its effect on such things as, air pollution and overseas balance of payments.

Jan 1, 1970

It is often said in business that if you donÆt have a customer you donÆt have a business. The same rule applies to project evaluation; if you donÆt have customers you really donÆt have a viable project. It is therefore essential that in the early stages of project evaluation the following fundamental questions are addressed: What products will this project produce? Who are the potential customers? What are the customersÆ requirements with respect to grade and impurities? Do they have adequate capacity to take the production from the proposed project? Will the products introduce adverse effects in the customerÆs process circuits? Will additional waste streams requiring disposal be produced? In the past the attitude has been along the lines of the customer will take whatever we produce at the mine site. Times have now changed with customers now operating under much tighter environmental regulation with waste disposal becoming increasingly difficult. It would therefore be prudent that the principles of product stewardship be used as a tool in project evaluation. This paper will provide a general discussion on customer requirements and provide detail on case studies of the impact of mine products on smelter process circuits. It will provide examples where there were synergies between the mine product and the smelter circuit and where the mine product had adverse impacts on smelter performance.

Jan 1, 2007

The Mons Cupri Cu-Pb-Zn deposit is situated within a complex Archaean volcanic sequence dominated by rhyolitic fragmental rocks. This sequence is underlain by a 150 m group of rhyolitic ash flow tuffs with minor conglomerate and sandstone, and is overlain by approximately 180 m of dacite and andesite flows. The Mons Cupri sequence itself consists of several elongate or circular rhyolite domes, flanked by rhyolitic fragmental rocks ranging up to 400 m in thickness away from the domes. The lithology of clasts (typically 1 cm to 1.5 m in size) provides strong evidence that the flanking fragmental unit was derived by explosive eruptions associated with the rhyolite domes. An approximately 15 m thick shale horizon, bleached and silicified at its base, overlies both the rhyolite domes and the frag- mental unit. A south-dipping chloritic pipe-like body, with near-surface dimensions of 1,000 by 250 m and narrowing at depth to produce a cone-shaped cross section, lies within the rhyolitic frag- mental rocks about 250 m north of the largest rhyolite'dome in the Mons Cupri vicinity. Its east west elongation parallels that of the rhyolite dome. Ghost fragments indicate that the material in this fissure is a severely chloritized derivative of the rhyolitic frag- mental unit. The chloritic pipe is overlain

Jan 1, 1973

A company tax rate based on profitability return, or as more commonly expressed, a resource rent taxation scheme has been intro- duced at various stages in the past by both Australian state and commonwealth governments. At present a number of overseas countries are applying this form of legislation to the taxing of sections of their mining industries. Within this study, ways in which this type of tax has been used are examined. The form in which the tax can be applied varies. 1. It can be selectively or universally applied. 2. The base on which economic return is calculated can be selected in a number of ways. 3. It can start operating only when high profit levels exist, or alternatively be the basis of a total taxation scheme. The implication for the Australian mining industry of the introduction of different types of resource rent taxation schemes is assessed within the context of previously enacted systems.

Jan 1, 1978

Underground mechanized excavation in New Zealand has become more commonplace in civil and mining applications during the last three years. At one stage up to seven Dosco Road- header machines were being used on different projects around the country. The Huntly West Mine Drifts inclined at one in four were by far the most severe grade conditions that the machines were subjected to; however, other operations posed their own particular problems for the machines. Two major interrelated factors became evident as soon as the machines commenced at Huntly. These were traction problems on the grade and control of water, particularly on the invert.

Jan 1, 1978

By J Wiklund

The impact of non-ferrous smelters on their local surroundings is well monitored and guarded by various actors: the owners looking for profitability, the villagers looking for employment, the consumers asking for ever cheaper products and services, the government collecting taxes and all cherishing the environmental impact. Recent challenges facing the industry are various new doomsday projections: that we will be running out of base metals, that the ground we dwell on will be contaminated by the use of products. Smelters, such as BolidenÆs R÷nnskSr Smelter have a long history of increasing non-ferrous resources by recycling. It is shown that extraction and recycling of metals together with energy recovery can be integrated in a modern, profitable and clean smelter. Examples of efforts to further improve the business will be discussed such as flowsheet rationalisation, environmental investments, new feed from recycling and energy utilisation.

Jan 1, 2000

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