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Epicentres of recent shallow earthquakes in the region (3-12¦S, 126-150`E) were plotted to identify the various plate boundaries in the region, in particular the southernmost one marking the northern edge of the Australian plate. New and published fault plane solutions were examined to determine the style of faulting and state of stress along the Australian plate boundary. From east to west the boundary is first a subduction zone along the Solomon Islands, then a spreading centre across the Solomon Sea, a zone of compression and left lateral strike slip along the Papua Peninsula, almost pure thrusting across the centre of New Guinea and lastly left lateral strike silo through Irian Taya to the outer Banda Arc. The principal stress is very consistent, trending NW to NNW in a near horizontal plane, from the triple junction of the Pacific, Solomon Sea and Australian plates in the east to the Banda Sea in the west. Only along southern Solomon Sea plate margin which is a divergent boundary, is the stress different in type and direction.

Jan 1, 1987

By E Mroczek, M Climo, B Carey, M P. Simpson

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The composition and volume of geothermal fluids in New Zealand offers considerable potential for the extraction of various metals and minerals, as well as being a source of heat energy, steam and gases, and for use in generating electricity. While extracting products from geothermal fluids is technically feasible, positive economics is the key driver for commercial success; however, there is no assessment of this opportunity that identifies simple, cost-effective processing technologies and provides a greater understanding of the economic viability and barriers for implementing such technologies. The methodology that will be used to evaluate the commercial opportunities for New Zealand is discussed.CITATION:Mroczek, E, Simpson, M P, Climo, M and Carey, B, 2015. From waste to wealth – mineral extraction from geothermal brines, in Proceedings PACRIM 2015 Congress, pp 133–138 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By P A. Dowd

This paper describes an integrated approach to the evaluation of ore loss and ore dilution via geostatistical simulation of in situ geology and grade characteristics, simulation of blasting mechanisms and simulation of loading from a blast muck pile. The approach is demonstrated on a case study. The sequential Gaussian method is used to simulate in situ bench grades on the scale of the smallest selectable volume within a blast muck pile. The simulated grades of these component volumes are interpreted as the reality that would be available with exhaustive sampling. The simulated bench is subjected to a blast simulator, based on the SCRAMBLE model, which effectively moves each of the component model volumes to its final resting place in the blast muck pile. Ore/waste delineation and selective loading processes are applied to the simulated muck pile to determine the degree of selectivity that can be achieved by various sizes of loader and types of loading and to quantify ore dilution and ore loss. An in situ model representing the reality of knowing only the data and information that are available from specific grade control drilling and sampling grids is obtained by sampling the geostatistically simulated model on a specified grid. The volumes comprising the in situ model are then populated by estimates based only on the data and from the specified grade control drilling and sampling grids. Different drilling and sampling grids are used to generate different models, each reflecting the levels of data and information available. Selectivity is assessed as a function of the drilling and sampling grids as well as the size and type of loader. Performance is assessed against the ideal selectivity that could be achieved on the perfect knowledge model comprising the simulated values of each component volume. Costs, prices and financial criteria enable an optimal selection of the grade control drilling grid, size of loader, type of loading and blast design.

Jan 1, 2004

Traditionally, surface coal mines in the Western United States have been limited by economics to depths between 150 to 200 feet. Utah International Inc., however, is now planning to strip coal its San Juan Mine in Northwestern New Mexico to depths ranging up to 400 feet while uncovering 20 feet of steam coal. This method is cost-competitive with nearby shallower coal deposits and underground mining of the same property. How trucks and shovels can pre-strip for a dragline, along with results of the planning process, comparison with alternate systems, capital requirements, operating costs and comparisons with other coal sources are all detailed. Also discussed are the major problems anticipated, how they might be corrected, and potential improvements to the concept. Introduction The San Juan Deep Stripping Project will be situated at Utah International's San Jean Mine. The mine is in the Four Corners region, so-called because four states enjoy a common border point about 30 miles to the northwest.(see Figure 1). The area is a semi-arid plateau region with an average elevation of 5,200 feet, receiving an average of 6 inches of precipitation annually

Jan 1, 1981

By A Yame, P J. Pollard, E Atase, J Garu, M Tangwari, D R. Hastings, R W. Smillie

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Townsville prospect is situated approximately 4 km north of the Ok Tedi copper-gold mine in Western Province, Papua New Guinea. Drilling in the 1990s delineated a resource of >1 Moz of gold within shallow, skarn breccia-hosted mineralisation associated with quartz-carbonate infill, together with pyrite, chalcopyrite, pyrrhotite, sphalerite, galena, tennantite-tetrahedrite, arsenopyrite, marcasite, and a variety of Au-, Ag- and Bi-telluride minerals. The deepest of these historical holes (TVL034) also intersected copper-gold-silver mineralisation more than 100 m below the gold-rich zone that is associated with calc-silicate skarn breccia. Although copper-gold-silver mineralisation in DDHTVL034 is associated with clinopyroxene-rich skarn, it was also noted that garnet in the skarn breccia became progressively darker in colour with depth, ranging from green at shallow levels to dark red-brown at depth. This indicated that the skarn breccia is zoned, with more proximal garnet skarn at depth possibly indicating an association with porphyry-style copper-gold mineralisation.Based on this skarn zonation model, recent drilling at the Titan prospect, located approximately 500 m south of TVL034, was targeted at potential copper-gold silver mineralisation beneath shallow skarn breccia-hosted gold mineralisation. DDHTVL 081 intersected 46 m at 6.36 g/t Au from 68 m and 80.7 m and 1.67 per cent Cu, 1.27 g/t Au and 20.32 g/t Ag from 184 m. Exploration is now attempting to define the extent of copper-gold-silver mineralisation by defining structural controls on the skarn breccia together with paragenetic and mineral zoning data.CITATION:Smillie, R W, Pollard, P J, Hastings, D R, Yame, A, Tangwari, M, Garu, J and Atase, E, 2015. Exploration of the Townsville Cu-Au-Ag skarn, western province, Papua New Guinea – preliminary observations of paragenesis and zoning, in Proceedings PACRIM 2015 Congress, pp 593–600 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

Underlain by and intruded into the sedimentary rocks of the Transvaal Supergroup the Bushveld Complex is the largest known layered intrusion in the world and contains one of the richest ore deposits on earth. It has been the world's major source of Platinum Group Metals (PGM) since the mid-1900s with Chromite and PGMs the two most economically important components of the Bushveld Complex. The lower group (LG), within the critical zone, consists of seven chromitite layers and it is within this sequence of chromitite layers, the most important target of the lower chromitite group is found, ie the LG6 chromitite unit. The LG6 chromitite unit consists of a chromitite duplex composed of the lower LG6 chromitite layer (Steelport seam), averaging 1 m thick, overlain by a 0.66 m waste parting and a thin 0.34 m thick LG6a chromitite layer (leader layer).Two mining methods are commonly applied in the Bushveld Complex to extract the LG6 chromitite layer package. One method consists of footwall development utilising rail bound equipment to gain access to the orebody and then extracts only the LG6 chromitite layer by means of hand held rock drills and scraper winches. The second method is the use of mechanised equipment to access the orebody on the plane of the ore utilising bord and pillar mining method, which extracts the full mineral resource, ie the LG6 and LG6a layers. Conventional narrow vein stoping is often selected due to the large conventional mining skills base found in South Africa, the perceived cost and dilution implications of utilising mechanised equipment, and the difficulties of using mechanised equipment at dips above 12¦. The driving factor for mechanised mining is the perceived ability to access the orebody quickly and inexpensively, and extract the entire mineral resource package (LG6 and LG6a) while limiting capital expenditure and improving safety.This paper investigates these two commonly applied approaches, highlighting the benefits and problems associated with the two approaches. Comparisons will be made of the two mining methods and recommendations given for the mining engineer to consider before selecting the appropriate mine design.

Dec 6, 2010

By R Morrison, P Owen

Particle breakage is an essential part of mineral processing. The aim is to reduce run of mine mineral ore to an optimal size for liberating target minerals and for subsequent recovery by separation processes such as flotation. This size reduction is typically accomplished in a series of stages in a grinding circuit tailored to the properties of the particular mine ore. Commonly this involves two or more classes of equipment starting with crushers, followed by SAG mills and then sometimes ball mills. Occasionally, high pressure grinding rolls or other novel devices are substituted. Broadly, energy consumption increases and energy efficiency decreases with the fineness of the material produced by each piece of equipment. For many operations, up to 50 or 60 per cent of total greenhouse gas emissions from a plant arise from the operation of the comminution circuit with the majority produced by the finest grinding parts, such as the SAG and ball mills. Wear of mill liners and grinding media also add to greenhouse gas emissions generated by their manufacture. The need for continual cost reduction and increasing regulatory and social pressure relating to greenhouse emissions create a strong need for improvements in comminution energy efficiency. Traditional experimental and modelling approaches are not well placed to create the required insights into comminution fundamentals or facilitate radical step changes in performance. This paper discusses the role that advanced modelling (based on coupled DEM and CFD) can play in improving the energy efficiency and performance of existing mainstream grinding equipment and in the development of new ones with radically superior performance. Achieving this goal will also require an improved understanding of ore breakage and methods to include sufficiently realistic breakage models within the DEM models. Developmental issues for the modelling and the critical need for validation of the advanced model features are highlighted.

Jan 1, 2004

EQUIPMENT TO BE DISCUSSED It is the intention of this paper to discuss the transporting of large skid mounted equipment and track machines around open cut mines. By large I mean 100 to 350 tonne capacity being trans- ported on minesite lowloaders and the capability of moving loads of 300 to 1200 tonne by other means. It is also possible to move larger loads. The main factor in transporting large loads is eco- nomics and is a balance between the cost of the transporter and the increased production from the equipment being moved. For example it could be possible to shift a 7000 tonne dragline faster than their own means of propulsion, being the "walking feet" method. However for the cost of $10 to $12,000,000.00 or more you can afford to walk the dragline and suffer the production loss. Let us concentrate on the economically realistic. BOSICH FBT MINESITE LOWLOADERS 100 TO 350 TONNE CAPACITY. Why initially consider having such a transporter? Our experience has shown that initial enquiries evolve from mines requiring to move large drills, 50 to 200 tonne weight and large hydraulic excavators or backhoes which are track mounted. The reason for shifting them is to move equipment from a mining face to enable blasting, to remove to the central workshop for repairs, overhauls and routine maintenance, to transport equip- ment from one mine face to another, and for drills, to move from one drilling pattern to the next. The cost in terms of time lost and extra wear on tracked equip- ment easily justifies the cost of the transporter. The tracks on large drills and shovels are not intended for long distance walk- ing. These tracks are designed to move the machines to position for drill holes, or moving around the mine face. Long distance travel, ie generally 1 km or more, results in overheating of track rollers, track drive components and accelerated wear on tracks.

Jan 1, 1989

By Firmin K

The Mt. Tom Price orebody of Hamersley Iron Pty. Limited consists of a folded hematite - shale sequence capped by a layer of goethite. Consequently, variations in iron content occur within the orebody, and as the overall grade is below that required to make specification products, selective mining must be carried out. A necessary preliminary to quality control'of products based on selective mining is the production of advance data, on the tonnages and grades of material to be expected in future mining areas. Bench plans showing zones of different grades and types of material anticipated are prepared from structural geological information. The grades of materials on a bench are essentially governed by the positions and attitudes of the shale bands. Quality control is exercised by blending different grades and types of material in primary crusher feed. Iron grade is the prime grade consideration although sometimes the level of phosphorus content must be considered. Pre-production grades Are determined from assay of samples taken from blasthole cuttings.

Jan 1, 1980

I feel a little like the Parson delivering his Sunday Sermon, chastizing his parishioners for not coming to Church. Those who need to hear me are absent.Nevertheless, I hope that if you agree with what I am about to say you will go forth and spread the word.We often hear of the impact mining has on the community. I prefer tonight to deal with the impact some community attitudes have on mining, and I want to point out that the results of these attitudes rebound to the detriment of our society. I want to deal particularly with regulation, taxation, and proflts.In a civilization whose standard of living is essentially dependent on an adequate and reliable supply of cheap metals and fuels, it should be evident to Blind Freddie that mining must be encouraged.I must express concern at the constraints inflicted on the mining industry by our community. We tend to blame Government for our difficulties, but we must recognize that Government acts merely as agent for the community. It is fair to say that in a free society, if Government actions do not reflect the demands of the electorate, then it doesn't stay the Government. It is important though for Government, in framing its policies, to ensure that it is not unduly influenced by the loud voices of minority groups.The people of our nation have every right to demand that our industry meet certain criteria to be allowed to operate. We all wish to live in a healthy and congenial environment, and to have our individual comforts protected. It is essential, however, that the community realizes that its demands on the mining industry are affecting Australia's prosperity.Each new regulation and each new tax or impost has its effect on investment, employment, and national revenue. Restraints result in an increase in costs which in turn raises the minimum value of a mineral deposit which is economically mineable. It results in minerals, which could be mined under more favourable circumstances, remaining in the ground, perhaps lost for ever.

Jan 1, 1978

By Grobler H. P, Chitombo G. R

Production blasting of Dc Beers Consolidated Mines Limited, Koffiefontein and Finsch Mines involves both uphole trough rings of 9 to I I holes and near vertical 360 degree compound rings of 42-54 holes. The rate of production from these stages is dependent upon being able to achieve a specified fragmentation size range and this has driven the derivation of blasting practices to consistently achieve this target fragmentation. At the Dutoitspan Mine, in Kimberley, where mining of the kimberlite pipe is by block caving, 100 per cent extraction of the undercut level by ring blasting is essential. If this is not achieved, pillars are formed which not only inhibit the efficient initiation of the caving process, but also concentrates load onto the extraction level, causing damage to draw points and pillars. These two case studies demonstrate the importance of achieving optimum blasting performance for downstream mining efficiency; ie fragmentation for increased productivity at Koffiefontein Mine and 100 per cent undercut extraction for efficient initiation of the caving process at the Dutoitspan Mine. The case studies also serve to highlight the long road towards blast optimisation taken by De Beers Consolidated Mines Ltd (Koffiefontein. Finsch, Premier and Kimberley Mines) since 1989.

Jan 1, 1995

In 1972 the Marra Mamba Iron Formation in the Lower Proterozoic Hamersley Iron Province of Western Australia was recognised as a stratigraphic horizon with significant potential for high grade iron ore reserves. Within the Newman area the Marra Mamba Iron Formation has been subdivided into four strati- graphic units: Lower BIF member, Middle BIF and shale member, Upper BIF member and Upper shale member - and a standard natural gamma log reference section compiled for the entire formation. The recognition of the Upper shale member as an additional unit contrasts to the previously proposed stratigraphy. Enrichment of the Marra Mamba Iron Formation to ore grade (0)8 percent calcined Fe) in the Newman area is restricted to the Upper BIF member and to a lesser extent to the Middle BIF and shale member. Typical ore from Orebody 29 is friable interbedded martite-ochreous goethite, signifi aptly different both physically and chemically from the Brockman Iron Formation ores of the Tom Price-Whaleback type. Large scale customer acceptance trials (in excess of 4 million tonnes) have shown that Marra Mamba ore crushed to fines and blended with Mt. Whaleback fines in a ratio of up to 15:85 forms an acceptable sinter feed.

Jan 1, 1981

By D Thomas, B Gallagher

Valuable data for geotechnical interpretation and integration into effective Australian underground mine planning may often be available, yet is not always fully appreciated or utilised, particularly in the early stages of mine planning or in due diligence studies. There may be considerable benefits associated with early prioritisation of geotechnical evaluation and impact on mine planning. Unidentified, misinterpreted, or ill-defined adverse geological and related geotechnical resource characteristics can pose significant business risk to underground coal projects and operations. Preliminary resource definition in the early conceptual mine planning stages attributes significant focus (entirely warranted) on resource quality and structural geology constraints. Yet detailed geotechnical data analysis and interpretation, which may have a substantial down stream impact and sensitivity with respect to future mine planning strategies, at times is given lower priority, or scoped and resourced in the later stages of a bankable feasibility study. Through extensive mine planning experience and observation of downstream process impacts, it has been found there is often data available for geotechnical analysis that does not readily stand out or is not adequately understood or utilised, available at the early (conceptual) stages of mine planning. Part of the issue may be that exploration geologists are not necessarily experienced geotechnical engineers and do not necessarily recognise or understand all important parameters. Subject to appropriate application of experienced professionals data can be manipulated to provide key geotechnical hazard assessment at minimal cost, and provide a framework for understanding and optimising the mine planning process. Although there is no single prescribed strategy for resource evaluation from a geotechnical perspective, potential business risks and mitigation approaches can and should be adopted at the conceptual mine planning stage. There has been a recent focus in the metals industry to provide a reporting framework for geotechnical classification of mining projects. This paper outlines the strategies and gives examples of key analyses adopted in mine planning and discusses the relative merits of adopting a reporting framework as a tool for geotechnical classification in mine planning.

Jan 1, 2005

By T Lancaster

The Mount Gordon operation, consisting of the Esperanza open cut mine and the unique Mount Gordon Ferric Leach processing plant, is operated by Western Metals Copper Ltd at Mount Gordon, 125 km north east of Mt Isa. The processing plant treats predominantly the secondary copper sulphide minerals, chalcocite and covellite. The gangue consists of massive pyrite and a range of silicified siltstones. The processing plant utilises a conventional single stage SAG/cyclone milling circuit, followed by low-temperature/low-pressure autoclave oxidation to produce copper in solution. The pregnant leach solution is treated via conventional SX/EW technology to produce copper cathode. Currently the plant is operating at a nominal production rate of 48 500 tpa copper. The Mount Gordon Ferric Leach technology is the worlds first integrated pressure leach/SX/EW process to be used to treat copper sulphides on a full plant scale. In the last six months, July to December 2001, the plant has emerged from a two-year postcommissioning phase to achieve steady state operation. This has been characterised by high plant availability and consistent production performance in excess of the name plate capacity of 45 000 tonnes. Production rates will continue to increase over the next 12 months to over 50 000 tpa via a planned process of incremental improvements. The pressure leach circuit has consistently achieved availabilities exceeding 95 per cent over the past 18 months. Notwithstanding this, the leach circuit still has a much greater requirement for planned maintenance than SX/EW. For much of the Mount Gordon processing plantÆs operating life, the leaching process has constrained production. Recent developments arising from detailed mass and energy balance modelling have now significantly improved leach capability, resulting in the plant bottleneck being shifted to electrowinning. In order to balance the capabilities of the two circuits however, the surge capacity between leach and SX/EW was increased substantially. This effectively de-coupled the higher capability but lower availability leach circuit from the lower capability but higher availability SX/EW circuit. As a result, electrowinning utilisation has increased to in excess of 98 per cent, which is reflected in a higher overall plant throughput.

Jan 1, 2002

Driefontein Gold Mine together with Kloof Gold Mine and Beatrix Gold Mine forms part of Gold Fields South Africa. Driefontein Gold Mine is situated near the town of Carletonville, 50 km south of Johannesburg, in the Gauteng Province. The 4 Shaft East complex comprises of the 4 Main Shaft and the 4 Subvertical Shaft. The main shaft is 9150 m in diameter and was sunk in 1984 to a depth of 2000.5 m. The 4 Subvertical Shaft is 7320 m in diameter and was sunk during 1985 to a depth of 3006 m. Full production was, however, only reached during 1988. Intensive mining is currently being done between levels 28 to 42. In 2002 a decision was made to start mining the shaft pillar, situated between 32 and 33 level in the subvertical shaft. Intensive studies showed that with selective mining scheduling the total mineÆs life could be lengthened by nine years if accessed timeously. The higher grades present in the shaft pillar can be mixed with lower grades from the same reef band presently mined 1500 to 2000 m away from the subshaft pillar area. The shaft pillar comprises 50 per cent of the remaining ore resources available. However, no provisions were made in the initial phases of the shaft development to extract the shaft pillar. Grades between 4300 cmgt to 2500 cmgt relating to 23 and 14 g/t are present in the shaft pillar and an estimated 50 tonnes of gold can be produced from this pillar in the period from 2007 to 2015. The pillar extraction is the key to DriefonteinÆs long-term gold profile. Every geological feature possible is represented in this to-be-mined pillar area. The pillar around the shaft is a complex structure featuring hard and soft lava, sedimentary structures/plane parting that moves against each other, quartzite capping, etc. Replacement of services and secondary support systems were designed, modelled and put in place. The original steelwork was not designed to cope with the various stresses and movements, which are expected once the extraction process is started. Existing shaft steelwork was used as far as practically possible. The principal behind the design was that the steelwork would be totally disconnected from the shaft lining over its total length of 132 m in the area of the reef intersection. This will allow the steelwork to move independently from the geological structures surrounding it, allowing a certain degree of distortion of the shaft lining, moderate twist and tilt to take place without interfering with hoisting operations.

Jan 1, 2005

By Sneddon NW

Aberdare North Colliery is situated on the eastern boundary of the City of Cessnock in the Hunter Valley, New South Wales. Although the area is now noted for its wines and vineyards, the district has a long history based on coal mining. The richest coal seam in the Cessnock district is the Greta Seam, a low ash, high volatile steaming or gas making coal. The seam, up to 10 metres thick, extends over a large area surrounding the city of Cessnock and neighbouring townships such as Bellbird, Aber- dare, Kearsley, Neath, Ellalong, Kurri Kurri and Stanford Merthyr. The Aberdare Colliery, leases, which extend under Aberdare and Cessnock townships, were first worked in 1905 and continued developing pillar panels until the mine closed on 11 Nov- ember, 1960. Coal mining to this time consisted mainly of developing pillars to the 2.4 metre parting and, in some areas, dropping the top coal to the 6 metre parting, thus leaving the pillars intact, the top 1.8 metr-es of coal be- ing left untouched due to the high sulphur content. Aberdare North Colliery was opened in 1956 in order to recover and extract the pillar coal and tops left standing for over 40 years. During the pillar extraction phase the occurr

Jan 1, 1981

High interest to basic-ultrabasic rocks is ex-plained by their specific, sutural, geotectonic po-sition and by deep level of generation of ultraba-sic magmas. These two factors allow us to treat this group of rocks as valuable source of informa-tion about the lower crust and upper mantle of the Earth. Basic-ultrabasic xenolith series is another source of information about the interior of the Earth. Detailed studies of the xenolith series give valuable material to geologists as to how endogenic deposits are fed and what is their source.Besides, the interest is explained by attempts to understand the relationship between basic-ultra-basic complexes and deposits of metalliferous and non-metalliferous mineral material.Absence of genetic boundaries in manifestation of metalliferous and non-metalliferous minerals, their temporal and spatial relationship allow us to treat the minerogenesis of ultrabasic complexes as a result of one ore-forming process manifested in Koryak-Kamchatsky, Sakhalin-Japanese, Ryukyu-Korean and Taiwan-Philippines island arc systems which re-present, in the opinion of the authors, one eastern Asian chain of the Pacific ore belt (Radkevich, 11)87).

Jan 1, 1990

The metallogenic belts of the Central Andes (iron, porphyry copper, polymetallic and tin) are genetically related to an eastward migrating magmatic arc. The polymetallic belt of the Bolivian Altiplano formed during Miocene arc broadening and lies in a critical position for understanding the genesis of this zonation. It is penecontemporaneous with parts of the copper and tin belts, and shares many characteristics with them. The differences between the belts result from contrasting volcanic and feeder stock geometry, depth of erosion and country rocks, and are not due to variations in magma chemistry, age or Benioff Zone depth. Polymetallic mineralisation in the Altiplano is epithermal in style and mostly related to flow-dome volcanism. The intermontane basinal setting precludes deep erosion to expose the epizonal feeder stocks and predicted porphyry copper mineralisation. In contrast, erosion of the less abundant stratovolcanoes of the Altiplano-Puna and Pampean Massif may expose contemporaneous Miocene porphyry copper mineralisation in subvolcanic stocks. The tin belt is coincident with the Paleozoic fold belt of the Eastern Cordillera. The occurrence of minor tin in Altiplano epithermal deposits hosted by Paleozoic sediments, and the persistence of tin mineralisation in the tin belt over 350Ma, suggests that Paleozoic sediments are the source of the tin.

Jan 1, 1987

By Biswas AK, Hayes P

During the reduction of iron oxide pellets in the blast furnace it has been found that catastrophic swelling (up to 300% volume increase) can occur. Although the burden preparation conditions can be designed to avoid this phenomenon the exact reason and mechanism of the swelling has yet to be clearly identified. Swelling of the burden is undesirable since it reduces the interparticulate voidage in the blast furnace thus reducing gas flow through the stack resulting in low production rates of iron. The present study differs significantly from previous experiments in that reduction is carried out on single crystals of wustite thus the problems of control of gas composition and specimen preparation are minimised. The microstructures formed on reduction have been examined by optical and scanning microscopy. Pure wustite and wustite doped with various levels of CaO have been examined after reduction in controlled CO-CO 2 gas mixtures at 968¦C. The catastrophic swelling on reduction coincides with the formation of an unusually open iron structure in which the iron appears as whiskers or needles as previously reported. The spacing and thickness of the needles are shown to vary with impurity content and gas composition. Metallographic examination has shown in addition, however, that the whiskers do not necessarily constitute the only product form of the iron produced and in CaO containing wustites with less than - 2% CaO there is a transition from needle growth to porous growth of iron. Thus the % swelling of the oxide particles is dependent on the initial size of the oxide grains. Samples of FeO - 10% CaO exhibited a previously unreported product inorphology associated with the nucleation of 2CaO.Fe203.

Jan 1, 1980

Exploration for uranium in Australia has so far discovered reserves equal to 17.5% of the Western World's. The Australian uranium industry, when fully developed, will be one of the largest producers and possibly the largest exporter in the world. The world's nuclear industry is young, rapidly developing in size and technology and is subject to more social, political and regulatory controls than any other industry. This paper considers the probable development of Australia's uranium industry against a background of normal commercial parameters together with other factors which are peculiar to the nuclear industry. As the theme of this conference is "Australia's role in the World Mineral Indus- try" this paper concentrates on the commercial and practical aspects associated with the development of Australia's uranium resources in a world context.

Jan 1, 1979