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By L Whitbourn, K Yang, P C, E Ramanaidou

The potential of hyperspectral mineral mapping within a mine environment is demonstrated. Central to this capability has been the development of portable or vehicle-mounted, hyperspectral mine face-mapping systems. Data from these systems were used to detect subtle mineralogical variations and map their distribution across rock faces in a fashion that previously was not possible. In one study, the data usability was enhanced by ædrapingÆ the mineralogical determinations over a three-dimensional æmodelÆ of the rock-face. The eventual melding of the spectral mine face-mapping and three-dimensional spatial technologies will result in a new generation of mineralogical and structural information becoming available to mine geologists, engineers and metallurgists. Specific uses for spectrally-derived, mineral mapping data sets could include:ore grade mapping systems based on either direct detection of ore minerals themselves (eg iron and nickel oxides), or mineralogies that may be used as surrogates for ore-grade information (via various alteration minerals) after a suitable orientation survey; detecting mineralogies that have a deleterious effect on milling, metallurgical processing or have occupational health implications (talc, swelling clays, carbonates, asbestos, etc); selective mining and blending by collecting, processing and displaying such mineralogical images in near real-time to monitor ore grade and quality, and allow the separation of ore from waste during loading operations at the mine face; a mineral detection and mapping capability to assist in structural and geotechnical mine planning applications; and an enhanced geological detection and mapping capability for ore mineral species or alteration mineralogies that may be used to vector further mineralisation, update the existing mine ore model, or provide input to assist in the control of autonomous mining equipment. Within the Woodlawn open pit, Fe- and Mg-chlorites and phengitic- micas associated with sulfide mineralisation were detected and mapped. Subsequent studies using a second generation face-mapping system demonstrated the direct detection of ore-grade materials for iron-ore and nickel laterite mining activities. Satisfactory and meaningful results were extracted from data that were collected under a variety of challenging conditions. However, these non-ideal climatic and operational conditions would be expected under most operational situations in a mine environment. Development of a system using artificial illumination, permitting night-time (and eventually underground) operation and elimination of atmospheric absorption effects is underway.

Jan 1, 2006

The procedures for an audit and review process upon which continuous improvement programs may be based are described. The case for regular audits of mining operations to establish performance trends is advanced. Analysis of performance data using the parameters of the capacity equation used in conjunction with learning curves is described. The extrapolation of learning curves in performance target setting, operating and capital cost budgeting is advocated.

Jan 1, 1992

By B K. Hebblewhite, G Sharrock

The strength and deformation properties of a rock mass are important parameters influencing the design of civil and mining excavations or structures. The mechanical behaviour of jointed rock masses are controlled by the characteristics of discontinuities and the strength of intact rock bridges between discontinuities. To date, analytical, empirical and experimental methods have not captured the key mechanisms controlling the mechanical properties of actual rock masses with non-persistent joints. The emergence of the synthetic rock mass (SRM) in 2007 provides a promising approach for this purpose. In this paper a rock mass with non-persistent joints is analysed with the SRM model based on PFC3D. The influence of joint geometrical parameters on the uniaxial compressive strength (UCS), rock mass deformation modulus (Em) and failure mode is studied. Joint parameters include joint orientation, persistency, spacing and step angle. Prismatic numerical samples with dimensions 300 mm × 150 mm × 50 mm were generated and a sensitivity analysis of each joint parameter on UCS and Em was undertaken. The results show that of the parameters tested, joint orientation has the greatest influence on UCS. Minimum UCS occurs when the angle between the major principal stress and joint surface is approximately 60°. The joint step angle was found to have a significant effect on failure mode and a joint step angle of 90° is the most favourable joint orientation for step-path failure. The importance of joint step angle is highlighted in the discovery of a failure mode bifurcation point at joint step angles of 60° and 90° for joint orientations of 75° and 90°, respectively. For these parameters the failure mode transitions from block rotation to a new failure mode where the coalescence of cracks results in the formation of new small regularised blocks.

Sep 26, 2011

By Just J, Nguyen G, Dunn J. G, Graham J

A sample of pyritic gold concentrate was investigated by wet chemical and electron optical techniques. Sub-samples were roasted in a laboratory scale fluidized bed roaster in the temperature range 400-700¦C. The calcine was characterised, and cyanide-leached using a standard bottle rolling test. Gold extraction efficiencies varied with roasting temperature. At temperatures of 400 and 450¦C gold ex- tractions of less than 40% were achieved, but between 500-700¦C the extraction had increased to 93--98Z. The surface area of the calcine varied with roasting temperature, reaching a maximum at 500¦C. There was no correlation between the surface area of the calcine and the efficiency of gold extraction.

Jan 1, 1987

By A V. Nguyen

Spherical calcium dioleate particles (~10 ¦m in diameter) were used as AFM (atomic force microscope) probes to measure interaction forces of the collector colloid with calcite and fluorite surfaces. The attractive AFM force between the calcium dioleate sphere and the fluorite surface is strong and has longer range than DLVO (Derjaguin-Landau-Verwey-Overbeek) prediction. The repulsive AFM force between the calcium dioleate sphere and the fluorite surface does not agree with the DLVO prediction. Consideration of non-DLVO forces, including the attractive hydrophobic force and the repulsive hydration force, was necessary to explain the experimental results. The non-DLVO interactions considered were justified by the different interfacial water structures at fluorite- and calcite-water interfaces as revealed by the numerical computation experiments using molecular dynamics simulation.

Jan 1, 2005

The paper describes the reasons for developing, specifically in South Africa, dense medium processes to allow baths to operate at low (about 1,35) and high (about 2,0) cut points. Low density processing was developed to meet the demand for low ash coals; high density processing was developed to enable heavily contaminated raw coals, destined to be burned in captive power stations, to be de-shaled without loss of combustibles. The anticipated and actual technical difficulties of operating baths at such density extremes are described, and the results from operating plants outlined.

Jan 1, 1987

By Filmer AO

In contrast to the '50s and '60s, the period of the '80s and '90s seems likely to have low growth in demand but much greater levels of technological change. In such a climate there will be pressure on costs, productivity will continue to rise and competitiveness will be closely associated with maintenance of the most effective technology. The penalties for inappropriate investments, whether short sighted or mistakenly based on a particular view of the future, will be greatly enhanced. Accordingly, there will be a need for significantly improved anticipation of technical change and thus for better planning. Study of the funding and direction of the world's R&D effort can provide a useful input to the planning processes within industries and individual firms. Such a study also suggests some insights into the characteristics of those countries which have achieved substantial growth and high standards of living over the past two decades. These characteristics may offer significant reminders for our own development. The particular implications for the Australian minerals industry include the need for direction that is sensitive to changing market requirements and customer practice. This is not simply "more of the same." In particular it appears essential for both basic and applied R&D to provide a sound basis for the purchase and ongoing development of the new technology required to achieve international Competitiveness.

Jan 1, 1986

By Buizen M

The results of calibration trials conducted on parachute stoppings under a recently completed NERD&DC grant are presented. Applications of parachute stoppings, for rapid regulation and control of ventilation networks are described including use in mine recoveries, sealing sections and rescue work. Parachute stoppings are one of a series of non-rigid ventilation control structures specifically designed for quick installation in emergency situations, for use in high production/rapid advance areas and areas suffering roof-floor convergence.

Jan 1, 1988

By Leigh J. H

A history is given of the dust control techniques developed and applied by the mining companies at Broken Hill. A history of the regeneration works undertaken since 1936 is out- lined. Particular emphasis is placed on the stabilization of mine residue dumps which are located throughout a belt of mining leases in the middle of the city and which began in 1937. The establishment of vegetation for dust control techniques is discussed in detail and a case study is given of the successful revegetation of the sides of a 650 metre long, 350 metre wide and 35 metre high residue dump.

Jan 1, 1976

By Hatcher MI

Exploration undertaken at Copley diapir has located several occurrences of oxidized supergene and primary sulphide copper mineralization at the margin of the diapir or in adjacent country rocks. The mineraliza- tion is related to carbonate-rich epigenetic solutions which moved along major structural features closely associated with the intru sive diapir.

Jan 1, 1975

By Bhattacharyya AK

With increasing demand for more efficient production from the underground coal mines in the Southern Coalfields- of New South Wales, their design and operational aspects are constantly being reviewed and improved. One key area in such pursuits is the reliable design of stable and yielding pillars. The current designs of pillars based mostly on experience leads to unnecessary sterilisation of coal or strata control problems. To explore such mine design problems, computer based modelling is increasingly being applied. In the study described in this paper, the object was to determine the particular width of pillars separating three roadways in a panel at which the pillars yielded completely and their loads largely transferred to the unmined coal at the flanks of the panel. This was approached through a computer simulation of the behaviour of the strata around a panel, in which the three roadways were separated by pillars of progressively decreasing width. A computer program called FLAC based on the finite difference method was used to simulate the relevant strata behaviour in vertical sections. The appropriate in situ values of the deformability parameters relating to the coal seam, roof and floor were determined from the back analysis of some displacement measurements in such a panel. The process involved successive modelling of a vertical section through such a panel,starting with realistic values of the parameters and varying them until the measured and the modelled displacements agreed closely. Based on the results of the numerical modelling, the width of a yielding pillar for the given conditions is Suggested.

Jan 1, 1992

By M Kongas, K Saloheimo

Concentrating lower and more variable grade ore resources to meet acceptable concentrate quality criteria requires removal of significant amount of gangue minerals. Monitoring plant feed mineralogy and concentrate by on-stream analysis has significant economic benefits in concentrate quality and recovery optimisation. There is a need to develop a sensitive slurry on-line analyser for silica, aluminium, magnesium and other light elements.On-line XRF elemental analysis technology, which is a routine practice in base metal concentrators is not able to measure lighter elements than calcium from slurry. Too much of the X-ray fluorescence signal from lighter elements is absorbed by water. The limitations in the direct measurement of silica and other light elements have restricted its use in some applications. Some light element slurry analysers have been developed based on prompt gamma neutron activation (PGNAA) method but they have not performed up to the expectations. This paper describes a new on-line elemental slurry analyser and the results of on-line laboratory tests.CITATION:Kongas, M and Saloheimo, K, 2013. Online light element slurry analysis, in Proceedings MetPlant 2013 , pp 93-101 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

The Bureau of Mines, with a history of mining research since 1910, still seeks improvement in safety and health along with improvement and competitiveness in the mining industry. Much promise of such improvements lies in new technology, and this is particularly the case in the still growing coal mine sector, although much Bureau research is long term, high risk, aimed at new concepts.The miner's environment is a primary concern, involving technologies of contaminant monitoring and control in high production scenarios. Contaminants arising from diesel use, alternatives to high speed rotary cutting and more efficient dust removal are being addressed, and drilling efficiencies, better monitoring through unitising operations and insitu rock dust monitoring are particular features.

Jan 1, 1991

By B H. Yin, S Mendoza, M Nusheh' C W Bumby, A Zhang

Hydrogen-direct-reduction of iron ore in a vertical shaft furnace is a potential process that could significantly reduce CO2 emissions from the steel industry. This approach requires the pelletisation of iron ore fines, which then undergo high temperature induration to strengthen the pellets before they can be fed into the shaft furnace. Here we report on investigations into the disc-pelletisation behaviour of New Zealand titanomagnetite ironsand, and its subsequent induration and hydrogenreduction behaviour. Initial studies focused on the effect on pellet strength of varying ironsand particle size and induration conditions using bentonite and a commercially sourced carboxymethylcellulose binder. Green pellets formed with ironsand of average particle size of 65 μm exhibited optimal strength. The compressive strength of these pellets after induration at 1200°C for 2 hrs in air was measured to be 976 N. Interparticle bonding within the indurated pellets occurs due to a combination of titanohematite recrystallisation (from oxidation of titanomagnetite), and the formation of a liquid bonding phase due to interdiffusion with the bentonite and subsequent melting. Further investigation with various binders showed that a combination of both organic and inorganic binders was essential to achieve optimal pellet strength. Carboxymethyl-cellulose binders provides green strength, whilst inorganic binders such as bentonite promoted high indurated pellet strength. Hydrogen reduction tests in a thermogravimetric furnace showed that all the pellets could achieve a maximum reduction degree of 97 per cent at 1100°C, indicating that the different pellet preparation procedures had no significant effect on reducibility. Pellet recipes developed in this work are now being used to investigate vertical shaft hydrogen-DRI processing of NZ ironsand in a kg-scale laboratory reactor.

Sep 18, 2023

FaulIing west of the Mount Isa mine is described and is shown to be related to three groups of folds that have been recognized in the area. The first period of faulting postdates the first generation folding; these faulIs are regional faults (tectonic discontinuities) which are folded by second generation folds. The faulting accompanying the second generation folding divides the area west of the Mount Isa mine into four structurally and metamorphically identifiable blocks. The most prominent of these second generation faults is the Mount Isa Fault, which is characterized by a number of distinct zones of intense second generation folding and the presence of localized layers of mylonite. Only limited evidence for brittle deformation has been observed and the major movement appears to be associated with the plastic deformation of the rocks. Confined to the areas of second generation folding in the Mount Isa Fault are numerous third generation kink folds. A detailed description of the Mount Isa and other faulIs is presented together with evidence for their existence. The displacement accompanying this faulting cannot be established because of the complexity of the structure.Postdating these faults and all the folding of the area are minor cross faults.

Jan 1, 1973

By Partridge AC

In order to provide a'valid description of the performance of size classifying equipment it is necessary that a standard procedure be established for testing and for the subsequent expression of results. Such a standard would permit the valid comparison of alternative equipment and may provide a basis for the prediction of performance. An Australian Standard (AS 1634-1974) has been used as the starting point for an International Standards Organisation-(ISO) working group (of which the authors are members) charged with the preparation of an ISO Standard for the expression and presentation of the results of tests on coal size classifying equipment. The approach taken is applicable to all types of sizing equipment (cyclones, screens, dedusters, etc.) and should be suitable for adoption in the minerals industry as well as by coal preparation engineers. The background to the proposed Standard, is given,including a critical review of other frequently quoted performance measures, the procedures described in the draft are discussed, and an example given.

Jan 1, 1984

Today the application of computer programs for planning of mine-ventilation and for safety- analysis of ventilation systems is widespread practice in German mining. The computer program for network calculat- ion, developed at the "Mine Ventilation Testing Centre of the Westfalische Berggewerkschaft- skasse" allows the distribution of airflow and pressure in mines to be calculated. In a physically well founded manner it takes into account the natural ventilation as well as changes of volume-flow in the mine, which both are dependent on pressure and temperature. Compared to an incompressible treatment of the mine air these circumstances are of increasing importance with the increase of depth, air temperatures and fan-pressures'. This especial- ly holds for the calculation of airflows during failures of fans or for assessing the influence of open mine-fires on ventilation. The application of the program is very easy and its structure is made to fit the requirements of practice. For instance it takes into account the fan characteristics of all fans. For each planning calculated air- flows in all mine workings are compared to those of an eligible basic calculation or to measured airflows. In addition for the

Jan 1, 1983

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 A S. Venkatesh, A Das

The Precambrian iron ore of Singhbhum-North Orissa region of eastern India occurs as part of the horseshoe-shaped broad synclinorium known as the Iron Ore Group (IOG) of rocks, which hosts the most important iron ore deposits in India. The Jilling-Langalota iron ore deposits are part of the IOG. Detailed mineralogical characterisation of different ore types has been carried out using transmitted and reflected light microscopy. Scanning electron microscope-energy dispersive spectroscopy (SEM- EDS), X-ray diffraction (XRD) and X-ray fluorescence (XRF) have also been used with a view to test the amenability of these ore types for beneficiation requirements. It has been observed that haematite, martite and goethite are the main iron-bearing minerals. Kaolinite and quartz are the major gangue mineral phases. Considerable mineralogical, textural and compositional variations have been observed among the different ore types. Characterisation data reveals that the massive and hard-laminated ores are of higher grade with very few interlocking textures having haematite and martite as major mineral constitutents. The soft-laminated lateritic and friable ores are relatively low-grade varieties containing various proportions of impurities with complex interlocking textures. The soft-laminated and lateritic ores are porous in nature and contain friable oxide and hydroxides of iron along with kaolinite, gibbsite and quartz. The occurrence of kaolinite, gibbsite and hydrated oxides along the cavities and weaker mineral planes of haematite and martite has been observed. The friable nature and high alumina content of these ores are attributed to these secondary phases. The nature of these ores is responsible for producing large amounts of alumina-rich slime during mining and handling operations. Suitable beneficiation schemes have been recommended for each type based on detailed characterisation investigations on these ores.

Jan 1, 2007

Powercoal Pty Ltd operates eight underground coal mines in New South Wales and produces coal for both domestic power stations and the export market. Approximately 40% of total production is from continuous miners. Over the past five years, place change mining methods have been introduced to improve productivity from continuous miners. This has involved utilising the existing coal clearance system from the continuous miner to the ratio feeder using trailing cable shuttle cars.By late 1996 average productivity at Cooranbong Colliery using this system had plateaued at 800 tonnes per eight hour shift. A number of factors were identified to increase average productivity to 1500 tonnes per eight hour shift. An improved coal clearance system was one of the factors identified.

Jan 1, 1998