Search Documents

By McKenzie C. K

During a programme of explosive performance evaluation at Hamersley Iron, Mount Tom Price Mining Operations, the relative performances of a range of heavy ANFO explosives were compared during normal production blasting operations. In addition, a number of heavily instrumented single hole blasting trials were conducted with each product type. The blasts were monitored in terms of blasthole velocity of detonation (VOD), measured using multi-point plasma conductivity probes with up to 16 measurements per blasthole. Up to 16 blastholes were monitored in each production blast. The results of measurements show a marked difference in performance of all heavy ANFO products between single blastholes and full production blasts, indicating a significant degree of interaction between blastholes in production blasting. The interaction is shown to result in a loss of detonation pressure of explosive, and considered to lead to a loss of fragmentation. The degree of interaction is seen to increase with increasing emulsion content in the products, and is more pronounced in some explosive types than others. The paper presents the methods of measurement and analysis, and the results of monitoring, together with implications on blast design and application of heavy ANFO products.

Jan 1, 1990

By Vogwill R. I J

The Boddington Gold Mine, operated by Worsley Alumina Pty Ltd, is located about 100 km south of Perth and is one of the largest-producing gold mines in Australia.Multiple open pits are planned and several extend below the water table, through the deeply weathered lateritic profile and into the underlying Archean bedrock. Groundwater related mining problems, such as poor trafficability, wet floor conditions and slope instability began to occur early in 1990.The mine is located within Archean greenstones which are steeply dipping and faulted. Rock types include mafic to felsic volcanics, pyroclastics and sediments. These rocks have been regionally deformed and metamorphosed and are intruded by quartz micro-diorites and post-mineralisation dolerite dykes. Deep weathering has produced a typical oxide profile consisting of laterite, clay and saprolite zones underlain by weathered to fresh bedrock.

Jan 1, 1993

Christmas Island contains large deposits of phosphate minerals varying from high-grade calcium-phosphate (apatite) to lower grade iron and'aluminium phosphate (crandallite/millisite). The surface material is dominantly C-grade (Fe/Al) phosphate profiling into B-grade, a variable mixture of C- and A-grade ores, before reaching the high A-grade phosphate (apatite) which overlies a limestone Karrenfeld Base formation. A-grade ore is the basic phosphate used for the manufacture of superphosphate and phosphoric acid, whilst B-grade contains amounts of iron and aluminium which are unacceptable for these acidulation processes. Research into methods of separating the finer iron and aluminium phosphates from the coarser calcium phosphates has led to the development of wash-screen processes enabling recovery of 50 to 60%, as A-grade phosphate. Developmental stages included laboratory investigations, mineralogical studies, pilot tests leading the initial 20 tph prototype production unit and the current 100 tph production wash/screen plant, commissioned early in 1970 at Christmas Island.

Jan 1, 1971

Mining is an intensive resource development industry, where operations are often of relatively short duration and can result in dramatic impacts on the natural environment during the operational period and for many years post mining. An integral component of all mining operations is water û through exploration, resource definition, mine development and operation, rehabilitation and the long-term post-mining land use. Water is a basic requirement in the provision of worker amenities, in drilling, as a means of dust suppression, as a medium for washing or processing the mine product, and as an aid in establishing vegetation on post-mining landforms. Water also plays an important role in mobilising environmental contaminants and is the primary medium for the transport of contaminants off the mine or processing site into the wider environment. It is for this second reason that the mining industry considers water management as a key component of mine management. Cost-effective water management relies on planning that incorporates a total mine system approach commencing prior to exploration and continuing through to rehabilitation and decommissioning. One of the primary considerations that will provide confidence to both government and community at the time of mine closure and lease relinquishment, will be the evidence that any water originating from, or passing through, the mine site is of a quality that will not have any negative impact on the surrounding environs into the future. The role of vegetation in stabilising disturbances to a landscape is well known, as is the recognition of vegetation being a fundamental component of the water cycle through the physiological processes resulting in the transfer of water back to the atmosphere through transpiration. In terms of water management at a mine site, the two crucial issues are the æquantityÆ and æqualityÆ of water that enters a receiving æoff-leaseÆ catchment. In terms of tolerances of the receiving environment, the total load of potential contaminants becomes critical, a reduction in which can be achieved through reduced volumes of water discharged, reduced chemical and physical concentrations of contaminants in that water, and ideally, both. This paper examines the potential role of vegetation in reducing the quantity of water released from a site, and secondly considers vegetation in the role of influencing the quality of that water.

Jan 1, 2003

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 Gyasi-Agyei Y

In recent years rapid advances have been made in the technology used for hydrology and erosion modelling of rural catchments. These advances have been driven by the growing availability of digital terrain maps that can be used to automatically define catchment properties that previously had to be manually extracted from contour maps. In addition, these models have, in principle at least, more powerful predictive capability. The author is involved in a number of projects to migrate and further develop these models for application to mine rehabilitation assessment. Current technologies for hydrology and erosion assessment (eg CREAMS, ANSWERS) are reviewed, underlying principles highlighted and deficiencies in the context of mine rehabilitation design assessment addressed. The advantages and disadvantages of the new digital terrain map tools (eg WEPP, SIBERIA) are discussed. Current work integrating these new models with existing rehabilitation design tools (eg ACIRL's ARGUS computer package) highlights the advantages of an integrated approach using digital terrain maps; cheaper, faster, lower impact and more flexible rehabilitation design. The use of novel visualisation tools to aid the design process is discussed. The paper is illustrated by applications to mine sites in Queensland and the Northern Territory.

Jan 1, 1995

A review of major mineral processing and extractive metallurgical developments is made and current areas for research are discussed.

Jan 1, 1975

By Jancar T, de Guzman M M, Matthews B, Tu J. Y

The use of computational simulation to predict the performance of existing equipment or for the design of improved mineral processing equipment will be referred to as Computational Mineral Processing (CMP) in this paper. The emphasis will be on solving the governing equations for liquid solid flows in complex geometric domains to obtain, typically, the three-dimensional distributions of velocity and pressure for the liquid phase and the velocity and concentration for the solid phase. The underlying technology, computational fluid dynamics (CFD), is very well-developed in other industries (aircraft, car and chemical) and forms a vital part of product design and analysis. The subsequent design of improved mineral processing equipment may also involve finite element structural analysis (FESA). Computational fluid dynamics (CFD) and finite element structural analysis (FESA) are part of the generic discipline of Computational Engineering and Science (CES). Ciment and Scherlis (1993) define CES as `The systematic application of computing systems and computational solution techniques to mathematical models formulated to describe and simulate phenomena of scientific and engineering interest'. Increasing computer power (Kaufmann and Smarr, 1993), is a dominant factor determining the rapid growth of industrial utilisation of CES. This increase is happening at both the supercomputer and the workstation level. Indeed, today's typical workstation, a Hewlett-Packard 735, is as powerful as a CDC 7600, the leading supercomputer in 1970. Future computer architectures are expected to become increasingly parallel (Gartner Group, 1990) allowing a sustained performance of a teraflop (a million megaflops) to be achieved well before the Sydney Olympics in the year 2000. It is recognised that the modem development of most disciplines in the physical sciences rests on the three complementary strategies of experimentation, analysis and computational simulation. As the 21st century is approached the volume of computational simulation, both fundamental and applied, is growing dramatically and the role of experimentation is diminishing. In the area of equipment design, CES provides the following advantages over experimental testing and measurement: 1. lead time in design and development is significantly reduced; 2. CES can simulate conditions not reproducible in experimental tests; 3. CES provides detailed and comprehensive information; and 4. CES is more cost-effective and time-efficient. The ultimate benefit for industry is greater productivity and hence greater profitability. The broader issues in relation to CFD are discussed by Fletcher (1993b). In the five- to ten-year time frame, growth in computer power will make it practical to combine CFD and FESA with optimisation procedures to produce a design process that is almost fully computerised. It is expected that fully automatic

Jan 1, 1995

The Cleveland Mine has an annual ore production of 400,000 tonnes at a grade of 0.79 per cent tin and 0.30 per cent copper. It is achieved by an open stoping method, mechanised overhead sub-level benching. The operation is trackless with a ramp access from all working places to the surf- ace. Broken material is loaded from the stope and development headings into diesel trucks and hauled to the surface crushing plant.

Jan 1, 1977

Modelling of Magnetic Carrier Separation Process Using Computational Fluid Dynamics

Sep 13, 2010

By Stanton RL

Stratiform lead-zinc mineralization in the Soldiers Cap Group and Kuridala Formation of the Mount Isa Inlier is closely associated with iron-rich sedimentary units or "iron formation", and has many similarities to the Broken Hill deposit in New South Wales. Both the Soldiers Cap Group and the Kuridala Formation have been intensively explored for deposits of this type since the early nineteen- seventies. A mineralized belt of at least eight significant prospects has been identified, of which the Pegmont deposit is the largest and best known example. In most cases the mineralized horizons contain banded galena and sphalerite within a gangue of predominantly quartz-garnet- pyroxene-amphibole rock, sometimes containing a variety of other metamorphic silicates, and apatite. Chemically, the mineralized horizons are distinguished by higher than usual levels of one or more of total Fe, MnO, CaO and P205. Interpretation of patterns of mineral- ization within the belt is based on the Pegmont deposit, where a model of base metal sulphide deposition within restricted basins of iron-rich chemical sediment has been developed (Stanton and Vaughan, 1979). Broadly, the model envisages the deposition of higher grade lead-rich mineralization in the basin centre position, lower grade zinc- rich mineralization in a basin intermediate position, and much weaker copper-rich mineralization in a basin edge position. These three positions reflect a laterally continuous arrangement of silicate microfacies within the original iron-rich sediment.

Jan 1, 1984

By Haslam C. O, Taylor S

Four historical periods of Australian lead-zinc-silver exploration and development are identified.In the first period, 1841-1900, Australia's deeply weathered surface yielded bonanza deposits. The outcrops of easily worked secondary ores, enriched in silver and lead, were discovered by prospectors with the incentive of production at times of high silver price. Districts discovered in this period still contributed, in 1982, 60 per cent of Australia's lead-zinc production, mainly from Broken Hill.The second period 1901-1944, was one of strong mine development but stagnant lead-zinc-silver exploration. Mount Isa was discovered and developed, but otherwise effort was devoted mainly to the mining of deposit extensions and to the metallurgical flotation of zinc. The deposit discovery rate was low but the discovery of Mount Isa was so significant that discoveries of this period contributed, in 1982, 30 per cent of Australia's lead-zinc production.The third period 1945-1972 was one of re-invigorated exploration.New geological and geophysical surveys, developing concepts of ore genesis, and worldwide comparisons of orebody settings improved target area selection. Evolving remote sensing methods, and rapid analytical techniques, assisted detection of lead-zinc deposits. Initiation of exploration led to discovery:1. in regions of previously unsuspected lead-zinc-silver potential (Sorby Hills, Mons Cupri, Golden Grove).2. of poorly exposed deposits in recognized mineral districts (Hilton, H.Y.C., Woodlawn, Elura, Que River).3. during active exploration for another commodity (Brown's, Woodcutters, Mary River, Beltana, Lady Loretla and Pegmont).The period saw a sustained growth in lead-zinc-silver production mainly from established operations. Mines discovered during the third period contributed, in 1982, 7 per cent of Australia's lead-zinc production.In the fourth period from 1973 to the present, exploration initiatives became fewer but resulted in continued discovery of poorly exposed deposits at Teutonic Bore, Thalanga, Benambra, Scuddles, Hellyer, and Jillawarra. Development initiatives strengthened in the period and production commenced at Woodlawn, Teutonic Bore, Que River and Elura; pre-feasibility work commenced at Scuddles, Hilton, Lady Loretta and Thalanga.

Jan 1, 1984

By Arumba J

In the Mount Victor area of the Eastern Highlands Province, re- connaissance geological mapping and new micropalaeontological data have revealed the existence of at least three small thrust- bound windows exposing late Middle to Late Cretaceous (Late Aptian-Early Albian and Late Santonian-Maastrichtian) sedimen- tary rocks and pillow lavas, Latest Paleocene- Earliest Eocene pillow lavas, and Latest Paleocene-Earliest Eocene bathyal micrites. Late Middle Eocene to Late Eocene inner neritic bioclastic micrite units also occurs in thrust contact with Middle Miocene Yaveufa Formation volcanolithic conglomerates. The Cretaceous and Early Tertiary units appear to be thrust-bound and are best exposed in a window just south of Mount Victor, and in two smaller windows to the east. The inner neritic Eocene limestone occurs in a thrust-bound sliver within the Yaveufa For- mation near Obura. The windows occur within extensive out- crop of Early Miocene Omaura Formation and the Yaveufa For- mation. Thin-bedded grey mudstone, siltstone and sandstone, typical of much of the Chim Formation form only a small part of the exposure of Cretaceous rocks. Thick-bedded volcanolithic conglomerate, spilitic pillow basalts, and welded basic tuffs domi- nate the Cretaceous section. The stratigraphy and structure of the Mount Victor area is similar to the Menyamya area, the Aure Scarp, and perhaps the Tapini area. This study has raised the possibility of widespread thrust- ing in the Kainantu area, and suggests that the boundary between the Omaura and Yaveufa Formations is thrusted, at least locally.

Jan 1, 1997

By Takagi T, Seetharam R, Sie SH, Naito K

Tin-polymetallic vein type deposits are one of the major source of metal producers in the Circum Pacific Belt. This type of deposit is of great importance for the modem electronics and medical industries because of their high content of rare metals (especially indium and bismuth). We have studied two representatives, Tosham of India (Cu-In-Bi-Sn-W-Ag-Au), and Mount Pleasant of Canada (Zn-Cu-In-Bi-Sn-W), using proton and electron microprobes in order to delineate the distribution of medical/high-tech rare metals. The electron microprobe study showed that major indium carrier in such type of deposit are roquesite (CulnSZ), sphalerite, stannite and a Cu-Zn-Fe-In-Sn-S mineral; and that indium is incorporated in sulfides by coupled substitution like Cu + In = 2(Zn + Fe). The proton microprobe showed that indium at trace levels is also present in chalcopyrite and pyrite. In addition, zinc, copper, arsenic, antimony, selenium, tin, and bismuth are common in chalcopyrite and pyrite. Arsenopyrite contains nickel, copper, zinc, silver, tin, antimony and bismuth. In chalcopyrite and pyrite, zinc, arsenic, indium, bismuth and lead are higher in Mount Pleasant ore, but silver is higher at Tosham. Also thallium and gold were found only in Tosham pyrite. The Tosham deposit is genetically related to S-type magma, while the Mount Pleasant deposit is related to A-type granite. Tosham ore contains zinc-bearing biotites that coexist with chalcopyrite in ore bodies but Mount Pleasant ore lacks such biotite. We propose that the difference in elemental abundance between the two deposits are caused by the different character of source magma and different mineral associations of the ore body.

Jan 1, 1995

Consideration was given to the.applicab on of a solvent extraction circuit to be'included in the process'for the-recovery of a high grade product from.:-the Rum Jungle Creek.South uranium ore body.The economics of two alternative processes, firstly the Eluex process which uses an ion exchange process followed by solvent extraction.-of a.high grade sulphuric acid eluate, and secondly a process using direct solvent' extractioh of pregnant leach liquor, were studied. There was a small cost advantage favouring the Eluex process but when other factors were considered, the installation of a direct solvent extraction process appeared the better long term investment. A solvent extraction plant was installed at Rum Jungle in 1962.

Jan 1, 1963

By Weber D, Knox PR

The criteria developed for the Argyle Diamond Mine process plant control system are reviewed. The control system installed is described along with a discussion of the method of implementation adopted. The control system was extensively tested prior to instal- lation at site. This approach led to signi- ficant time savings during plant commissioning and facilitated rapid escalation of plant production. The control system has performed satisfactorily with a high level of operator acceptance and basically satisfies the criteria Developed.

Jan 1, 1986

The mined-out Old Waite volcanogenic Cu-Zn deposit lies in the Noranda mining district of northwestern Quebec. The deposit has a distinctive pipe-like zone of alteration beneath the massive ore, extending into the stratigraphic footwall. The hydrothermal metasomatism within the alteration pipe produced a concentric zonation. with a peripheral quartz - sericite - chlorite mineral assemblage surrounding an axial core of magnesian chlorite - Phlogopite.

Jan 1, 1989

Ranger Uranium Mines Pty. Ltd. operates an open pit mine and ore treatment plant in the Northern Territory designed to produce 3 000 tonne/yr of U308 in yellowcake from 3 500 tonne/day of mill feed. The construction of this project was completed in 1981, 12 years after the discovery of the orebody. Wright-Davy, a Joint Venture of Wright Engineers and Davy McKee Pacific, were the Project Managers and Designers of the $270 million ore treatment plant and associated infrastructure. The project was designed in Sydney in -an office integrated with the Client, staffed by 35 key personnel drawn from Wright Engineers and Davy McKee, supplemented by personnel hired for the project. The peak Wright-Davy workforce in Sydney of 200 contained 113 design staff. The design principle of using the best practicable proven technology resulted in a plant which easily produces its design output using ore types outside the design criteria. The structuring of the project systems and industrial relations policies contributed to construction being completed within time and under budget. The plant was built without any major industrial dispute occurring and no dispute arose due to the uranium issue.

Jan 1, 1983

Solar Salt, Lunar Ambitions I Bauerti The title of this paper is `Solar Salt, Lunar Ambitions'. It is largely the result of a lack of imagination and a tight deadline. I was seeking a catchy title to convey the image of being 'here' and wanting to get `there', with `there' being a long way away and our being held 'here' by powerful gravitational forces. I tried `Solar Salt, Lunar Landings', but that implied we had already reached `there' when, on reflection, we had not. A colleague suggested 'Solar Salt, Luna Park' which is a fun park in Sydney and, I must admit, there was appeal in the image of having embarked on a wild roller coaster ride with stomach-wrenching twists and turns and the only reward being a pair of sweaty palms, and a feeling of nausea. That's sometimes how it feels when you launch into change. In the end I settled for the more sedate `Lunar Ambitions'. It contained that suggestion of hope and continual striving which are central to the idea of best practice. I will discuss our experiences in this area shortly, but I would firstly like to provide some background to our business. The salt industry is steeped in history and tradition. As one learned commentator observed, common salt is 'a substance seemingly too ordinary to think about, yet it is the oldest of man's raw materials and the basis of some of his newest inventions' (Multhauf, 1978). From ancient times, salt was recognised as a key necessity of life and it has played a role in the rise and fall of governments throughout history. The Romans recognised its importance when they gave their soldiers money regularly to purchase salt, hence our modern word 'salary'. Today, while culinary use remains important, the main consumer of salt is the chemical industry (Figure 1).

Jan 1, 1995

By R K. W Merkle, E Whiteman

The anorthosite complexes and related rock types of the Indian Precambrian shield are primarily associated with either cratons or mobile belts. They were metamorphosed under amphibolite to granulite facies conditions. The major rock types are chromite-bearing meta-anorthosites, amphibolites, basic granulites, pink granites and gneisses. This study was carried out on chromitite bearing samples from Sittampundi Anorthosite Complex (SAC), Tamil Nadu, to evaluate the nature and textural settings of platinum-group minerals (PGM), using state-of-the-art technology. The structure and petrology of SAC were well studied by earlier workers (Subramanian, 1956), but only scanty data on geochemical, petrology and mineralogy of PGM are available. The mineralogy of the samples is dominated by chromite (>70 mass per cent), plagioclase (An90) and chlorite-actinolite with orthopyroxene (En85). Details of the petrological evolution of the Sittampundi complex will still have to be studied further, but indications of magma replenishment at the level of chromite formation and the elevated PGE values associated with the chromitite samples make the Sittampundi complex a promising target for future exploration activity.

Jan 1, 2008