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By M A. Gontalves, A F. D C Varajpo, S A. Stachissini

Clays from the Santa Elena Peninsula, south-east of the Ecuador coast, were investigated with a view to identifying their main mineralogical, physical, chemical and textural characteristics as well as their potential for industrial use as adsorbents. Identified as calcic bentonites, two representative samples from the Tosagua Formation (Oligocene to Lower Miocene) were selected for acid activation trials. The selection criterion was based on the greatest amount of clay fraction (<2 ¦m fraction) associated with the greatest content of montmorillonite. For the activation treatments, HCl and H2SO4 solutions of 4, 6 and 8 N were used in a stirred glass reaction vessel with the clay sample under reflux during four hours at temperatures of 70¦C for HCl and 85¦C for H2SO4. Mineralogical analysis by X-ray diffraction (XRD), chemical analysis by X-ray fluorescence (XRF), differential and gravimetric thermal analysis and measures of density, surface area and porosity indicated the changes occurred in the crystal structure of the montmorillonite. The acid treated clays were utilised in trials of purification and decolourisation of soybean vegetable oil in a ratio of 2:100 (clay/oil) at 90¦C for 30 min, under constant stirring. After centrifugation of the suspension, the wavelength of the bleached oil was measured by UV-visible spectrophotometer and the bleaching capacity of the clays was determined. The best bleaching capacity of the samples was obtained with 6 N H2SO4 acid-activated clays. The bleaching capacity was compared to Tonsil, a commercial acid-activated clay and similar results between them evidenced the potential industrial application of the Ecuadorian clays to bleaching of vegetable oil.

Jan 1, 2008

Willemite mineralization was discovered in 1966 in the North Flinders Ranges of South Australia, in the course of a stream sediment sampling programme. Further work outlined a total of nine separate willemite occurrences in the Copley/Beltana area, and ten small deposits in the Toondana area south of Parachilna. Mineable reserves of 1 000 000 tonnes grading 36.8% zinc were outlined in three deposits in the Copley/Beltana area and campaign mining of the Main Orebody commenced early in 1974. The main group of deposits all occurred within red, dolomitized Cambrian Ajax Limestone, and most are associated with significant thrust faulting. The area of the Main Orebody group of deposits has been intensely fractured, and the surrounding dolomites are often brecciated and contain up to 5% zinc. Lead and arsenic mineralization are minor components of the main group of deposits. Masses of Middle Proterozoic Willouran Formation crop out adjacent to or close to most of the deposits in the Copley/Beltana area. The Willouran is frequently highly sheared, brecciated, and often contains large inclusions of younger formations. It is believed that most of the Willouran outcrops represent piercement structures.

Jan 1, 1975

Before commencing design of a coal prepar ation plant, it is essential to have detailed information of the raw coal to be treated to- gether with a clear understanding of the products required. Prediction of raw coal size distribution, particularly the amount of fine material, is difficult and the methods employed should be large scale pilot plant studies or techniques to simulate coal degradation and shale breakdown in water. A detailed knowledge of well proven coal preparation processes and new developments allows processes and process combinations to be compared to'obtain the maximum economic recovery when using lower cost, less efficient processes within acceptable limits. Equipment should be selected bearing in mind its precise application and the location where it is installed. Plant layout should be carefully studied to minimise equipment requirements and to simplify construction. Measurement, control and automation should be an integral part of plant design in order to obtain the optimum performance of the processing equipment.

Jan 1, 1974

Design of underground extraction layouts to protect surface improvements is an important area of subsidence research in the Coal Mining Engineering Branch of the Department of Mineral Resources, New South Wales, Australia. Some conventional partial extraction layout are important with reference to coal recovery and surface subsidence. The analysis ofsubsidence data collected from field surveys over longwall panels in the Southern Coalfield of New South Wales allows assessment of the effect of pillars left unmined between the longwall panels in reducing surface subsidence. The availability ofa wide variety of layouts with ranging degrees of surface movements affords considerable flexibility in designing layouts to suit a particular situation.Total extraction of coal should be the aim as far as possible. Partial extraction layouts should only be considered when surface subsidence movements caused by total extraction are not acceptable to the surface improvements.

Jan 1, 1985

For many years the mining industry at Broken Hill, New South Wales, Australia, was carried on with just sufficient attention to underground ventilation and hygiene conditions as to keep pace with necessity. However, the campaign against industrial diseases in other mining centres (notably South Africa) some years ago, brought the subject more prominently before local mining engineers.Throughout a period of several years, gradual improvement has been effected, and at the present time industrial hygiene is considered an essential part of the production operations of the various companies.In June, 1918, a move was first made by the Board of Trade advising an inquiry respecting the health of employees engaged in the metalliferous mining industry in the State of New South Wales. At the end of that year, a recommendation was made to the State Government by the Board of Trade that a Techni.cal Commission of Inquiry be appointed to examine and report upon the dust conditions of the metalliferous mines at Broken Hill. Following this a second report presented in 1919 made specific recommendations in respect to the scope of such a Commission. A Technical Commission of Inquiry was accordingly appointed and arrived in Broken Hill to inquire into the prevalence of miner's phthisis and pneumonoconiosis in the mines. Early in March, 1920, the examination of all mine employees commenced, and the work was completed in June, 1920. The full report of the activities of the Commission and the conclusions arrived at was officially published at a later date. Based on the recommendations...

Jan 1, 1940

By Gomm SA

The Mount Tom Price Concentrator, which contains a heavy medium cyclone plant for beneficiation of the -6+0.5mm fraction of low grade iron ore, is described. Testwork was carried out on an opportune basis over a period exceeding twelve months, to evaluate the separation performance of the heavy medium cyclones. Plastic density tracers were used and ore samples were taken and analysed. The effect of operating medium specific gravity (S.G.) on the separation parameters, the iron grade of the sinks product, and the mass and iron recoveries were investigated. Also examined were the differences in perform- ance between particles of different size. The implications of the findings for plant oper- ation are discussed.

Jan 1, 1987

By G Kluck, N Stoitis, D R. Seaman, R A. Lauten

The presence of clays, in particular clay slime, may complicate many mining operations. Clay slime particles may possess a negative or positive charge depending upon the pH in the process and their presence may lead to reduced recoveries in flotation processes. It is assumed that slime particles may adsorb onto the surfaces of the minerals to be floated and by doing so, reducing the efficacy of the flotation chemicals. In this work it is shown that addition of a small amount of dispersant, either a polyacrylic acid or an anionic polyphenolic polymer, increases the recovery of copper and gold, both in laboratory trials and in plant testing of an ore with high clay content. Measurements of adsorption isotherms reveal that the tested dispersants show preferential adsorption towards the clay minerals present, suggesting that the improved recovery upon dispersant addition occurs by prevention of attachment of clay slime particles onto primarily chalcocite but also chalcopyrite.CITATION:Seaman, D R, Lauten, R A, Kluck, G and Stoitis, N, 2012. Usage of anionic dispersants to reduce the impact of clay particles in flotation of copper and gold at the Telfer Mine, in Proceedings 11th AusIMM Mill OperatorsÆ Conference, pp 207-214 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Oct 29, 2012

The goal of the Bureau of Mines, U. S. De- partment of the Interior, diesel engine research program is to reduce exhaust emissions and mini- mize the risk of fires and explosions caused by the use of diesel-powered equipment in under- ground mines. Significant results of research conducted during the last 5 years are briefly described, with references to published reports on specific topics. Topics covered here include brief discussions of a newly completed diesel research laboratory, the effects of a fuel addi- tive on diesel exhaust particulate matter, the effect of diesel engine maintenance on emis- sions, a diesel particulate filter for equipment used in underground metal and nonmetal, and coal mines, and lastly, the prototype hydrogen- powered mine vehicle. These research accomplishments could favor- ably affect the mining industry by reducing the health and safety hazards associated with the use of diesel-powered equipment in underground Mines.

Jan 1, 1988

Australia contains a variety of iron ores, differing in grade, chemistry, size distribution and genesis. While a proportion of this ore is used world-wide as blast furnace lump, much of the material mined is high grade fines, requiring agglomeration (usually sintering) before blast furnace reduction. Sintering studies initially concentrated on the production of ferrous material of high iron content, coarse size and sufficient cold strength. In recent years research involving pilot plant sintering, precise test procedures and mineralogical analyses has focussed on the additional sinter properties of hot strength and reducibility. Aspects of mineralogical studies applied to iron ore sintering are described.

Jan 1, 1989

By M Coulthard, J Rivalland, K Dugan

Prior to 2001 Yallourn Mine has pumped approximately 1000 Megalitres of water per annum from aquifers beneath the mine floor in order to control aquifer pressures that were thought to have an influence on mine floor and permanent batter stability. In 2001 one of the deep aquifer pumps was shut down for five months in order to measure the aquifer recoveries. Prior to the shutdown a UDEC model was created in order to predict what level of recovery in the aquifer pressures would be critical to mine stability. The shutdown showed that the aquifer levels recovered and stabilised at levels that did not threaten the stability of the mine. The aquifers recovered to levels below the critical levels identified in the UDEC model.

Jan 1, 2003

By G J. Corbett

Magmatic-related low sulfidation hydrothermal ore systems at plate margins exhibit distinct spatial and temporal zonations which can be used to aid mineral exploration and development. Low sulphidation systems at all crustal levels exhibit the same paragenetic sequence of events: early breccia formation, followed by quartz - secondary feldspar sericite/illite veining, then mineralisation, and final argillic overprint. This sequence of events is interpreted to reflect the initial emplacement of melts at high crustal levels, and the progressive cooling of that melt and release of magmatic constituents into a circulating hydrothermal system.   Low sulphidation systems in the south-west Pacific region exhibit a vertical zonation in deposit types: from porphyry copper-gold at deep levels, quartz-sulfide-gold at mesothermal to deep epithermal levels, carbonate-base metal gold at mainly epithermal levels, and epithermal quartz silver-gold at shallow levels. It is interpreted that the characteristics of each of these styles of deposits is produced by mixing with circulating waters of different physio-chemical compositions.

Jan 1, 1995

By Nag D. K

King Island Scheelite is a wholely owned subsidiary of Peko-Wallsend Ltd. The company works two underground mines near the southern end of King Island at the western approach to lass Strait, 240 km south of Melbourne. (See ^igure 1).

Jan 1, 1981

By Tooley S. M

An experimental investigation of the hydraulic cuttability of coal from the Theiss Dampier Mitsui mine near Moura, Central Queen land illustrated the ability of established cutting equations to describe the behaviour of the coal during cutting. The experimental equipment developed for the work proved reliable. The results of the experimental programme are consistent with accumulated experience from overseas.

Jan 1, 1985

By Wilson PH

A research programme sponsored through the Australian Mineral Industries Research Association investigated two aspects of mine aerodynamics on model scale. These were aero- dynamic losses in (a) shaft/airway intersections and (b) losses created by mine cages moving in a combined haulage/ventilation shaft. The shaft/airway intersections studied included base and intermediate levels for both upcast and downcast. shafts, with one to four rectangular airways intersecting a circular shaft. Changes in intersection geometry were limited to the installation of 45¦ conical brow cutoffs of varying size and the addition of simple flow control devices. The relative air- flows between the airways and the downstream shaft were varied over a range employed in Australian mining practice. In general, experiments revealed that a small brow cutoff was significantly better than none at all, and a simple device such as a cone can reduce losses and improve flow stability at an intersection. The mine cage studies determined the effect on aerodynamic loss of cage area blockage, height/length ratio, openings in cage walls and surface roughness due to external structural members. The results show that in a combined haul- age/ventilation shaft, when the relative air

Jan 1, 1978

The quality of the rock mass in which an excavation is being driven has a strong influence on the level of dynamic forces to which the excavation can be subjected and sustain damage. Though each specific rock mass occurrence is unique yet there are common rock mass features which influence the outcome of controlled blasting in a similar way. A field study was conducted which involved assessment of blast damage at several operating mines and the blasting of small-scale models. The effects of block size and strength, joint parameters, ground water, weathering of rocks and rock mass rating on the results of controlled blasting have been investigated and discussed in this study.

Jan 1, 2003

British Coal's Selby Complex is the newest producing mine in the United Kingdom. The reasons behind its origins, planning and design are explained. Some detail is given of equipment used, with the emphasis being placed on the unique features of its layout. The entire project has been planned and constructed over many years and the design has consequently changed, principally in response to the geology of the coalfield and improving technology. In spite of many totally unexpected difficulties, the mine, which is not yet in full production, has the highest productivity in the United Kingdom.

Jan 1, 1991

By Hammond J. R, Ward T. A

The Tom Price orebody, in the Hamersley Ranges of North West of Western Australia, is mined by Hamersley Iron Pty. Limited. The orebody is a folded sequence of hematite and shale bands capped with goethite, with a con- sequential variable iron content. The overall grade is below that required to yield spec- ification product, necessitating selective mining, 'Zone Plans' based on geological structure have been developed to yield forward information on material types and grades. Short and medium term mine plans - the initial stage of quality control - are based upon these 'zone plans'. Blasts are laid out to break to the grade boundaries, thus minimising dilution, and the samples taken from the blasthole cuttings provide blast grades. Blending of shovel out- put from different blasts forms the operational basis of grade control. Shales, being more friable than hematite, produce fines that are lower in iron grade than lump. Quality control in the mine centres around maintaining the target fines grade, compensation being applied in the mine if the fines grade lies outside the target range.

Jan 1, 1973

By Purvis A. H, Greenwood-Smith R, Sowerby B. D

A nuclear technique for the determination of copper and nickel in bulk samples and drill core has been developed at Lucas Heights andfield-tested at Mount Isa. The technique, which is highly specific to the element being measured, utilises the gamma-ray resonance scallering process.A bulk mineral analyser was installed in mid-1976 for the routine assay of copper in bulk samples and drill cores, and remained in operation until late 1981. The operation of the analyser over this five-year period is reviewed with particular emphasis on reliability, accuracy and principal usage.The main application of this analyser was in stope planning and design whereby several thousand drill-core and Wall-chip samples were analysed. It was also used as an aid to underground grade control of stopes where ore dilution by supporting barren backfill was a problem.

Jan 1, 1984

By King D, Dickinson S. B, Matheson R. S

Graham Hall and V. M. Cottle (Rosebery, Tas.) : In their paper on "The Mineralized Rift Valleys of Tasmania", Campana, Dickinson, King and Matheson have summarized a wealth of data from many sources. In proposing the new concept of a rift valley structure, they claim to have found a new guide to regional ore control and distribution in North-west Tasmania.Although the authors acknowledge suggestions made by us prior to publication of the pa:per, we are still at variance with their conclusions. We are not convinced that a rift valley structure exist~d when the Ordovician conglomerate was deposited. We are unable to find evidence for Cambrian deposition in a rift valley or reason to project the structure to embrace Hercules, Rosebery, and "possibly" Mt Bischoff.That the Great Lyell Fault (the authors' Owen Rift Fault) is a promising place to look for ore is not a new idea, but the existence of important ore deposits away from the structure reveals its inability to provide an adequate explanation of regional mineral distribution. A well-known structure that does have an influence on ore deposition is not discussed by the authors.STRUCTURAL CONSIDERATIONSThe great thickness of coarse unsorted Ordovician conglomerate lying in an elongate but narrow belt of country is presented as evidence of its deposition centrally within a rift valley, the position-of which is now said to be outlined by resistant slabs of the conglomerate. The marginal shears of the rift are said to show up well along the edges of the conglomerate.

Jan 1, 1959

By M J. Nugus

A substantial cost is invested into the data collection phase of any exploration or development program; notwithstanding, it is impractical to expect a database of information can be collated to ensure a perfect geological interpretation. The question then becomes, is there a possible alternative interpretation and what is the likely impact of the variations? Modelling in 2005, of the Cosmo lode at Sunrise Dam Gold Mine, Western Australia led to consideration of the philosophical implications associated with resource management. It was concluded that several plausible geological models could be constructed from the known geological database. To varying degrees, this predicament is common to all geological reconstructions, as several alternative geological models can be generated at almost any stage that will impact on the resultant resource estimation and mine plan. The significance of that variation and the associated risk of multiple geological models (MGMs) requires due consideration. What is being suggested is that using plausible multiple geological models advances the holistic understanding of a mineral deposit within the bounds of the data collected, providing fluidity for updating geological knowledge and building inherent variability into the design and planning departments where variations of the geological models may materially impact on the resource performance.

Jan 1, 2006