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By Peak DJ, Kearton CJ

Following a summary of the development of a BF model using aerodynamic relationship and bulk fines index a blast furnace policy model is presented complete with the development of nomograms and featuring production rate, oil rate and total fuel rate. Application of the blast furnace model is then illustrated using No. 5 Port Talbot as an example. It is also shown how the policy model assists in ore allocation in the British Steel Corporation. Further developments which have recently occurred in the correlation between the bulk fines index and the permeability coefficient are detailed and a comparison made with a number of furnaces operated elsewhere. The implications of the comparisons made are that high driving rates are possible with burden containing a high proportion of sinter only if the burden behaviour in the lower parts of the furnace permits high driving rates with a steady gas distribution and low pressure drop. It is concluded that the value of a simple set of equations resulting from the model assisted furnace operators to pin-point likely causes of failure to reach or sustain target production rates.

Jan 1, 1975

By Croggon R

Passing a direct current through a jointed fine grained soft rock mass auses the movement of water by the process of electric-osmosis. There are other processes such as electrolysis which transport ions that interact with associated ions and can, in turn, be oxidised. This results in the dissolution products being transported towards the cathode electrode. In the cathode region the ferrous hydroxide is oxidised to ferric hydroxide %%ith consequent precipitation. The cracks and joints are current pathways, along which the ferric hydroxide is deposited. This deposition reinforces the joints and increases the shear strength. By adding calcium chloride to the anode, the rate of corrosion is increased with the concomitant increase of deposited ferric hydroxide along the joints. This, in turn, significantly increases the joint shear strength. The process is pervasive in that the current via the water paths travels through the crack and joint systems The result is that not only specific joints are reinforced but the cracks and mtciconnected voids are also reinforced.

Jan 1, 1997

By S Meffre, A E. Fallick, K Zaw, I T. Graham, G Giuliani

Dispersed gem corundum is mined from placers, commonly from basalt fields, as occurs along eastern Australian and Asian continental margins. New laser ablation inductively coupled plasma mass spectrometry analysis (LA-ICP-MS) of Australian corundum allows genetic distinctions among these suites and gives clues to their primary lithospheric sources prior to basaltic delivery. Bimodal corundum suites at Barrington Tops, Cudgegong-Gulgong-Macquarie River and Yarrowitch, New South Wales (NSW), include lower Ga, higher Mg æmetamorphicÆ and higher Ga, lower Mg æmagmaticÆ groups. The Barrington Tops æmetamorphicÆ corundum is more Fe-rich (av 4500 - 7100 ppm) than Cudgegong- Macquarie River equivalents (av Fe 1800 - 2100 ppm). Yarrowitch corundum is relatively low in Fe, Ti and Cr. Along with other eastern Australian data (north-east Tasmania; New England, NSW) and from gem fields elsewhere, the combined trace element and O isotope data, reveal considerable geographic and genetic variations within the corundum suites. A few corundum groups contain noticeable Be, Sn, Ta, Nb, a particular genetic message that also precludes easy distinction of treated corundum in the gem trade. Expanding geochemical, inclusion and geochronological data on gem corundum hold promise for characterising derivative gem corundum on both geographic and genetic features.

Jan 1, 2008

By Hopkins G. M F

Intensive exploration of the Archaean ultra mafic sequence bordering the Kambalda dome has resulted in the discovery of at least ten dis- tinct areas of nickel sulphide mineralisation subsequent to the initial drill intersection in January, 1966. Sulphide ore reserves to June 30, 1972 were 19.36 million tonnes at 3.3% nickel after mining of 3.0 million tonnes at 3:7%,nickel since production commenced in March, 1967. About 75% of contained nickel metal reserves occur in sulphide concentrations located at the base of the-ultramafic sequence, in contact with underlying meta-tholeiitic basalt. The remaining reserve occurs in concentrations of sulphides within the ultramafic sequence, usually within 100 metres of the underlying contact and typically in proximity to contact mineralisation. These hanging wall orebodies are smaller, contain significantly lower con- centrations of sulphide, and generally exhibit higher Ni:S ratios than underlying contact ore- bodies. The majority of contact sulphides concentr- ations form narrow, elongate, north north-west trending bodies, closely coincident with fault bounded depressions in the contact. Detailed study of the Lunnon Shoot ore environment in- dicates that it was a locus of crustal failure during, and subsequent to, emplacement of ultra- mafic rocks. Resultant structures parallel and

Jan 1, 1973

Bougainville Copper Limited (BCL) ships about 600,000 dry tonnes of copper concentrate per annum to Japan, Germany and Spain, with some spot sales to other countries. Concentrate sales value for 1984 was 335 million US$, representing almost half of PNG exports. Contained metal determination is based on physical and chemical measurements on representative samples. The entire procedure is subject to statistical uncertainties and possible systematic errors; losses as high as several percent of contained copper or gold are common and frequently are regarded as unavoidable. In this context, the function of the chemical laboratory is to identify and eliminate such errors and recommend correct technical procedures for possible inclusion in sales contracts. BCL's marketing management has encouraged this approach and the close buyer versus seller agreement is beneficial for all parties involved. BCL participates in the respective technical committees of the Standards Association of Australia (SAA) and the International Standards Organisation (ISO). Standard methods for sampling and analysis of copper, lead and zinc ores and concentrates are in course of preparation, some being due for publication shortly.

Jan 1, 1986

In the Renison Bell area of western Tas mania, a series of Lower Cambrian quartzites, shales, carbonate beds ("dolomites"), cong- lomerates, tuffs and argillites have been folded into a broad monocline whose general strike is NW-SE, plunging slightly north and dipping NE. The downwarped eastern side of the monocline is disrupted by a steep (50-800) east dipping normal fault, known as the Bassett Structure, whose throw is in excess of 500 m. A series of flat north dipping normal faults, each with a throw of approximately 50 m, further disrupts the sequence. All major faulting was pre-mineralization. A cassiterite- bearing Devonian quartz porphyry body intrudes this Cambrian sequence 2 km south of the currently operating mine. Of economic importance is the presence of three carbonate beds in the sequence. These carbonates consist of a mixture of calcite, dolomite and siderite. The No. 1 (youngest) and No. 2 carbonate beds are each approximately 15 m thick and are separated by 20 m of hematitic conglomerates and tuffs. The No. 3 (oldest) carbonate bed is approximately 5 m thick and is separated from the No. 2 horizon by 50 m of dark grey, finely laminated shales and quart- zites. Whilst the carbonates are remarkably persistent over at least 30 km2, facies changes are common and as a result of these changes, the carbonates vary considerably in

Jan 1, 1973

By W Farnworth, D Fergusson

Estimation of productivity is a key factor in the design of hydraulic mines and in assessing their economic feasibility. A published Russian formula for hydraulic mining monitor cutting rates overstated productivity by up to 2 tonnes per minute (251%) when applied to Solid EnergyÆs hydraulic mines. A new formula, taking into account additional productivity factors, was derived by Solid Energy and produced an acceptable correlation between predicted and actual cutting rates inNew Zealand and overseas hydraulic mines, with an average error of approximately 0.1 tonnes per minute.   Another key factor in hydraulic mine design is the transport of coal slurry via flumes. Solid Energy carried out a series of 80 full scale tests in a surface flume installation, varying the gradient and coal:water ratio. Both steel flumes and plastic-lined flumes were evaluated. A modification of the Chezy Open Channel Flow formula, including a factor for slurry density, gave a reasonable correlation between actual and predicted flows. It is believed that this Solid Energy formula is suitable for the design of flume installations for hydraulic mining.

Jan 1, 2004

FINANCE FOR EXPLORATION Two factors have basic importance in relation to the availability of finance: the apparent success of continuing exploration activity and tax concessions. It is not proposed to discuss the effect of existing tax incentives, as these have already been outlined and are generally accepted as being reasonably attractive; certainly not a deterrent to possible investors. However, it is obvious that the greater the tax incentives, the greater the amount of money that will be attracted, and the wider the number of people who can be brought into the pool. If, as is suggested, the chance of discovery is related to expenditure and effort, then the more money attracted, the better the prospects of significant finds. It is probably correct to assume that the largest expenditure in mining will come from, or be induced by, people expert in the field, people who are fully aware of the risks and benefits and perhaps making conservative decisions because of this awareness. Insofar as the general public is concerned, while in the first burst of enthusiasm it will frequently follow any promoter, in the long run it too will become more sophisticated and will strongly support only those promoters and companies of good repute and proven record.

Jan 1, 1971

Project evaluation is completed through individual studies covering technical and financial aspects of the mine to market. These studies are completed at various levels of detail depending on where the project evaluation is in the projectÆs life cycle. The competency of the studies varies in relation to the quality of data, level of the skills employed, control, management and reporting structure. The focus of this paper is managing elements of the study, looking at the cost of opportunity to influence the project, against the value added. Selection of the study manager and study teams is central to getting an integrated project evaluation addressing the correct issues completed on time. Retention of key personnel can reduce rework which, in turn, can reduce time and cost impacts. It is important to have a work breakdown structure at the outset so that the study teams have a common numbering and naming system that will integrate areas, equipment, budgets estimates and accounts. Having set up the evaluation groups and provided training in the study procedures, understanding the scope and schedule are vital elements in producing a project evaluation that addresses the opportunities and the risks of the final project. Arriving at an accurate capital budget requires integration of the research controlled through common systems. Project evaluation process must also address how the project is to be delivered.

Jan 1, 2007

The new South Australian Mining Act be came operative in July, 1972. It provides appropriate updated legislation covering pro- specting, exploration and development of mining properties. Anomalies inherent in earlier legislation which provided for the private ownership of minerals in certain areas have been overcome by the vesting of the property in. all minerals in the Crown. Appropriate transition- al and long term provisions protect the right of individuals thereby divested of their former property in minerals. In the matter of pro- specting for and quarrying of extractive minerals, the rights of landowners have been formally recognized, and the concept of rehab- ilitation of quarried areas has been introduced utilizing money provided from a royalty fund especially established for this purpose. Con- temporary company exploration practice is catered for under a new exploration tenement and at the same time the legislation makes provision for the interests of individual pro- spectors. Special provisions have been enacted to cope with the rapidly developing opal mining industry. A feature of the new Act is the introduction of legislation which recognizes enlightened contemporary thinking on the matter of environmental considerations. The Act has also extended the powers and widened the jurisdiction of the Warden's Court. In general,

Jan 1, 1974

Flue gases from electrical power station boilers, roasting, metallurgical and chemical plants could be treated by flotation using conventional flotation machines. The flue gases are introduced into the pulp instead of the air. The flotation media is a suspension of Ca(OH)2 or CaCO3 or a solution of NH4OH etc containing Na oleate as collector and frother. The SO2 and dust content of the initial flue gases were experimentally reduced by 100 to 1000 times in one flotation operation. The velocity of the flue gases through flotation machines could reach approximatively 0.4 to 0.5 m/s and more against 1.5 m/s reached in scrubber absorbers used for this purpose, but the quality of purification is expected to be better for flotation, which is essential for the cases of heavy polluted metallurgical and chemical flue gases. For some chemical plants the flue gases flotation media may be different and more suitable as compared to the above mentioned media. The proposed flotation method could be used for separation of dry grinded ores in the form of aerosols, with a realisation of flotation from a closed space (gas bubble in the pulp) onto the interface liquid-air where the particles are attached inside the bubbles.

Jan 1, 1993

By Rao A. B, Rao V. D

Northeast of Brazil is situated in the polygon of drought. It covers some very important states like Bahia,Pernam- buco, Paraiba, Rio Grande do Norte, Cea- ra and Piaui , which have a potential for mineral production. Of them the main contributions that comes from Rio Grande do Nor to , Ceara and Paraiba are the scheelite and im portant quantities of granitic pegmatite mine- rals like tantalite-columbites, micas, beryls, precious stones, lithium minerals etc. On the other hand flourishing mineral economy in gold, tin, emeralds, chromium, lead, apatite is most- ly from Bahia; and potassium, salts, and petro- leum are from Sergipe, Alagoas and Bahia res; pectively. The most interesting aspect coninues to be the nucleus of the drought zone constituted of the Rio Grande do Norte, Paraiba and Ceara sta- tes.The first two authors have worked for twel- ve years in the region and have dedicated atten tion and time to two systems, namely skarns and granitic pegmatites. Their mineralogy,petrogra- phy, geochemistry, origin and economy is being worked upon from time to time to accompany the progress that is being achieved both in the sec tors of geology and economy. Besides, during the field campaigns, evidences have been sought to find the best guide horizons for mineralisa- tion and options for the location of target areas and prospection methods for scheelite, tantalites and other pegmatite minerals.

Jan 1, 1988

Modern technology and the need for published results have created the tendency for exploration to concentrate on drilling and assaying rather than building a broader geological understanding. Though grade is vitally important to a resource estimate, density and volume are also very important aspects that require equal consideration. Wet tropical nickel laterites are developed in humid environments over ultramafic bedrock where the nickel and cobalt are enriched to economic levels by weathering, leaching and supergene processes. These laterites often occur over rugged terrain at higher elevations where there is sufficient rain and stability for the long lateritisation process to occur. For nickel laterite profiles, the variable terrain and significant material type changes within the relatively thin profile make density and particularly volume estimation, just as significant as grade in resource estimation and assessment of resource risk. Drilling alone is generally not a cost-effective way to reduce the risk in laterite volume estimation to acceptable levels. Surface geological mapping, high resolution topographic data and other information such as ground penetrating radar (GPR) can be used very effectively to improve volume estimates. These data types are all differently structured, have different data density and quality and may potentially overlap. Integration of these disparate data types provide the most cost-effective approach to modelling wet tropical nickel laterite volumes and minimising risk. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By Emerson D. W

The search for economic mineral deposits is becoming more difficult as exploration goes deeper in the established mining camps and spread out to the surrounding covered areas, which may have an `overburden' some hundreds of metres thick. Geophysics is finding an ever increasing role in such exploration. When the target is zinc, the task often becomes even more difficult since sphalerite, the most commonly mined mineral, is non-magnetic, resistive, and relatively light compared to other sulphides. Fortunately, sphalerite commonly occurs in association with other sulphides, which are magnetic and/or conductive and/or heavy, thus most zinc-rich orebodies have at least one contrasting physical property to aid exploration. This paper presents the physical properties of sphalerite and other potentially important zinc minerals. Results of petrophysical measurements of samples from various zinc-rich ores are presented together with examples of geophysical surveys over a number of zinc deposits. The results show that the physical properties are not merely dependent upon the properties of the orebodies' constituent minerals. For example, the small (0.4 Mt) and low-grade (five per cent Zn + three per cent Pb + two per cent other sulphides) Flying Doctor deposit at Broken Hill, New South Wales (NSW) is much more conductive than the large (3+ Mt) and high grade (14 per cent Zn + five per cent Pb) Cadjebut deposit in Western Australia (WA). In the former case, tectonic stresses have

Jan 1, 1993

I propose to speak today about our mineral heritage. In common usage "heritage" refers to the past. It means the discoveries, the developments, the mines and the processing plants, the benefits, the consequences, and the human experiences flowing from these. The history of the industry, inseparable from the history of the countries in which The Institute operates, is a rich background of which we can all be proud.But there is also a much wider meaning to mineral heritage. Our past has left us with the ab\lity to create and operate world scale enterprises generating wealth for the community, the ability to offer satisfying and challenging careers in a wide range of skills to our young people, and the willingness to follow adventurous and challenging vocations in remote areas, away from the big cities, at a time when the mentality of many is to get the most for the least effort and at the least inconvenience to themselves. The industry continues to be the repository of the pioneer spirit and a vital contributor to improving the life of the people in our countries.Thus, while our mineral heritage has much to do with the past, an essential part of it is how we use this rich past to build and shape our future. It is in this broader context that I am speaking today.

Jan 1, 1990

Trucks are the primary means of bulk material transport in Open Pit hard rock mines worldwide. They are considered to be the most- flexible system available. The large number of trucks used in some mines provides flexibility. Spare units allow for the reduced availability of the single units. Trucks have however very poor energy efficiency. Only 40% of the consumed energy is for transport of the payload, the remaining energy is required to move the dead load of the trucks. With the increase in cost, pressure, mine operators are now looking for alternative methods to make their operation more economical. Energy conservation and increasing haulage distances and uphill haulage are major factors in many well established operations. New methods have already proven themselves as more economical alternatives. Belt conveyors are an alternative means of transport with much higher energy efficiency. They use up to 80% of the consumed energy for transportation of the payload. Energy costs for conveyors are 30% of the energy costs for trucks on level transport and as little as 15% for elevating payloads. Belt conveyors require much fear spare parts and wear components than trucks. A factor of one to two times applies for level transport and ten to twenty times for uphill transport.

Jan 1, 1986

By Miskelly N

In Australia and New Zealand, the 'Australasian Code for Reporting of Identified Mineral Resources and Ore Reserves', which was released by industry in 1989, is operating successfully in a co-operative approach between industry and regulatory authorities. Similar codes or guidelines exist or are under development in the United States of America, Canada, the United Kingdom and South Africa, although the regulatory backing given to the Australasian Code is unique. International standard definitions for Mineral Resources and Reserves, and for categories of Resources and Reserves, have been under development by the Council of Mining and Metallurgical Institutions since 1994 and have already stimulated considerable convergence of definitions and reporting standards in participating countries. It is hoped that agreement on this international standard for public reporting by mining companies will be reached within the next two years, and it is expected that adoption of the standard will result in a higher and more uniform quality of reporting worldwide, with a consequently greater interest on the part of the general public and financiers in investing in the mining industry.

Jan 1, 1997

Hong Kong continues to display a remarkable enthusiasm for undertaking ambitious tunnelling schemes despite apparent recessions in the Asian economy. This paper provides an outline of tunnel projects currently under construction, those recently tendered and a glimpse of the extent of forthcoming projects which, according to Government sources, carry a price tag of HK$ 200B. Committed works will cost about HK$ 15B and involve a variety of TBM and drill and blast tunnels. These include the recently tendered works for KCRCÆs West Rail and MTRCÆs Tseung Kwan O railway extension, together with five no retendered TBM drives for the Strategic Sewage Disposal Scheme (SSDS) following forfeiture of the works by the Campenon Bernard-Maeda JV in mid-1997. The JV claimed unreasonable specifications leading to unacceptable levels of water inflow and dangerous working conditions. Key technical issues that are now arising in Hong Kong are:the general use of design and build contracts for bored tunnel contracts;a trend to accept TBM options for relatively short drives in urban areas;the use of æfixed-priceÆ contracts which in the current competitive market, can encourage tenderers to take contractors to take very high risks; andthe difficulty of predicting and managing water inflows in rock tunnels.This paper also includes a new empirical method of predicting water inflows in rock tunnels, and makes recommendations for managing these on-site.

Jan 1, 1999

The Osborne copper-gold deposit (within the Trough Tank project area) is located in the Cloncurry Shire about 195 kilometres south-east of Mount Isa. It is hosted by Proterozoic metasediments of the Eastern succession of the Mount Isa Inlier. The deposit is overlain by 25-40 metres of Mesozoic cover, so it represents a true "blind target". Placer Exploration has 100% outright ownership of the property, having purchased the remaining 10% interest in the property from Shell in early 1993.Intensive exploration, both surface and via drilling at Osborne, has taken place since 1985, when CSR Limited Mineral Exploration and Development Group (acquired by Placer in 1988) entered into a joint venture with Billiton Minerals. Exploration effort from 1985 to June 1988 outlined a 20 kilometre strike length of magnetic horizons, in what was termed the North-East, Central and Southern anomalies, which were drilled with weak indications of copper-gold mineralization in the North-East anomaly. During the later half of 1989, four core holes were drilled into the shallower northern partofthe North-East anomalywhere previous drilling had outlined economic intersections of mineralization. These holes encountered high-grade copper-gold mineralization confirming the potential for an economic deposit to be hosted within the ironstone sequence. Further drilling involving over 400 holes (100 kilometres of drilling) has brought the deposit up to its present resource status.The current resource inventory is 36 million tonnes grading 2.0% copper and 1.0 grams pertonne gold and includes a high-grade zone of 13 million tonnes grading 3.6% copper and 1.5 grams per tonne gold. The discovery of this potential economic mineralization resulted from a persistent exploration effort based on indications that a large mineralizing system existed within a sequence of ironstones.

Jan 1, 1993

The resistance of lead to chemical attack and the ease of its fabrication has made it one of the most useful of the metals available to the chemical engineer and the electrometallurgist. It has proved to be of particular value in the manufacture of sulphuric acid, and since the conversion of the sulphur of pyritic ores into sulphuric acid is becoming the duty of the metallurgist, the corrosion resistance of this metal will be a matter of considerable interest to him from the standpoints of both producer and user. He realises that there is little to be gained in carrying the process of purification past the ordinary economic limit if little or nothing is to be added to its corrosion resistance, and he as user would not be willing to pay a premium for such purification if it can be shown that its reputed value has no scientific foundation.The metallurgist is well acquainted with the trouble and expense of meeting demands which have nothing torecommend them but prejudice and fancy. The valuable anti-corrosive properties of lead are very commonly ascribed to its forming insoluble compounds with the acids sulphuric, hydrochloric, carbonic, etc. If we trusted superficial visual evidence alone, such a view would receive strong support, but in the light of what we know of the mechanism of corrosion we must attribute its resistance to other factors much less obvious to casual inspection. Certainly there may be some mechanical obstruction set up to diffusion of the liquids towards the surface of the metal.

Jan 1, 1932