Search Documents

With the launch of Immersive Technologies' next generation of Advanced Equipment Simulators for the mining industry, correlating and influencing safety, productivity and maintenance with operator competency improvements is now made even more effective. In early 2008, Immersive assembled a project team to investigate the potential linkages between operator competency and performance. Advanced Equipment Simulator Users with a range of sophistication were interviewed and consulted. The result was new and enhanced 'value realisation' programs to directly assist mine sites to deliver the expected return on investment (ROI) from simulators and operator competency development. In just over one year, 29 mine sites around the world have benefited from 34 completed programs. Case studies have been compiled to demonstrate the impact of the implementation of this approach, including at the following operations: Anglo Coal - Callide (Australia), Freeport McMoRAN - Grasburg (Indonesia), Equinox Minerals - Lumwana (Zambia), Peabody Energy - Cabllo (USA), and Xstrata - Lomas Bayas (Chile). Significant performance improvements have been achieved including: reductions of 47 per cent in gear shifting and 37 per cent in over speed errors, improvements of 68 per cent in park break errors and 12 per cent in spotting time, and increase of 54 per cent in passing emergency fire handling competency tests. This presentation draws on these case studies to clearly demonstrate the linkage between improved operator competency through the implementation of training programs tailored around Advanced Equipment Simulators and production performace measured by a range of standard metrics at mines around the world.

May 1, 2010

A recently developed technique for use in collieries is described in which samples of gas of relatively high vitiation value are obtained from points deep within a developing goaf by means of pipes. This technique prevents dilution of small quantities of carbon monoxide by large quantities of fresh ventilation air and eliminates interference from shotfiring gases. By using the technique it should be possible to assign a characteristic ratio of carbon monoxide to oxygen consumed to any district and to predict the onset of heatings.INTRODUCTIONGas analysis has played a vital role in detecting heatings in collieries all over the world. By analysing return air from a district and by calculating the percentage ratio of volume of carbon monoxide found to oxygen consumed (known simply as the "carbon monoxide ratio") it has been found possible, in many cases, to assign a characteristic ratio to a district under consideration. This characteristic ratio serves as an index of the spontan~ous combustion tendency of a goaf area. Any definite and consistent increase in the ratioabove the normal figure· indicates that a heating is developing and hence adequate preparations may be made to deal with the trouble.This ratio technique was developed by Graham (1920-21) who found (Table 1) that the temperature of oxidizing coal was directly related to the ratio obtained from analyses of the effluent gas.Until recently, most attempts to employ a similar technique in collieries working the Greta Seam (N.S.W.) were not successful. From experience gained over the past few...

Jan 1, 1961

By D J. Black

The process of longwall coal extraction coal causes fractures in the overlying and underlying strata and these fractures become pathways for gas released from adjacent coal seams to flow into the mine workings and contaminate the ventilation air. If the rate of gas emission exceeds the diluting capacity of the ventilation air, the gas concentration will increase and exceed the statutory limit resulting in production delays.All potential gas sources within the planned mining area, including coal seams located above and below the working seam, should be identified and sufficient gas data collected and used to determine the specific gas emission from each gas source. Gas reservoir and emission modelling is recommended to determine specific gas emission and changes in gas emission from individual sources over the planned mining area. Accurate gas reservoir and emission modelling provides the information required to accurately design gas drainage programs to effectively manage gas emissions and minimise the risk of ‘gas-outs’.Given the increasing occurrence of incidents of gas concentration in ventilation air exceeding the 2.0 per cent statutory limit and changes to mine plans to avoid ‘difficult-to-drain’ areas, it is apparent that many operations are not effectively utilising gas reservoir and emission modelling to identify high gas emission areas and are not completing sufficient gas drainage in advance of planned mining.The process of gas reservoir and emission modelling to support gas drainage design to control tailgate gas concentration and fugitive emissions is presented and discussed.CITATION:Black, D J, 2017. Gas reservoir and emission modelling to evaluate gas drainage to control tailgate gas concentration and fugitive emissions, in Proceedings Australian Mine Vent Conference 2017, pp 65–72 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

Technological advances evolve in different ways; many are the result of years of application of scientific method. i.e. Observation Deduction Hypothesis Proof In the mining industry, better explosives, drill bits or reagents are likely to evolve in this way. The scientific method is suited to the application of conventional management structures. Other advances are simply the result of a "brainstorm", or building a better mousetrap. Such inspiration probably resulted in "Split Set" rock bolts, or the first use of a vacuum cleaner principle for shaft mucking. Individual consultants can apply lateral thinking to generate such inspiration. In gathering material for the presentation of this paper, I sent a.letter to all members of the Mineral Industry Consultants Association asking them to nominate problems in the industry requiring investigation. The answers have been divided into two classifications - contract research underway and identified problems requiring solutions.

Jan 1, 1986

By Cullen JF

Australia has a large resource of manganese at BHP's Groote Eylandt mine which has been progressively developed over the last two decades. While much of the product is marketed internationally to the iron and steel industry, substantial quantities are processed in Australia at the Company's ferro alloy works in Tasmania. In addition, small but increasing quantities of ore are being consumed by the non-metallurgical industry. Fluctuating fortunes in the steel industry produce similar trends in the marketing of manganese. The increasing cost of freight and power together with strict environmental control is further affecting the market balance. Mine operators are expanding into the alloy making field. Reduction in usage in less developed countries is occurring.

Jan 1, 1982

The present-day arrangement of old ( ? ) Palaeozoic and Mesozoic metamorphic rocks in eastern New Guinea lends some support to the concept of tens:konal dilation in Upper Cretaceous to Lower Tertiary time, It appears that the metamorphic core of the Morobe Arc (Glaessner, 1950) could have been rifted from the eastern flank of Cape York Peninsula, and then been carried north-eastward by some unspecified sub-crustal. tangential force. In the early stages of the rift it is thought.that submarine basalts may have extruded up the .'tension .scar and spread across the floor of the opening rift. Thick clastic muddy sediments derived almost exclusively from the rifted block were then spread across the floor of the opening rift. Later ~ertiary lateral movements from east to west along the Markham-Ramu Fault appear to have bent the northern end of the Morobe Arc towards the.east,,causing the intense folding in the sediments of the Aure Trough.

Jan 1, 1962

By Misra V. N

Upgrading of a Koolanooka magnetite iron ore sample provided by Kingstream Steel Ltd was investigated using low intensity magnetic separation (LIMS) and reverse flotation. The ore contained 38.6 per cent iron, 37.8 per cent silica, 6.5 per cent magnesia and 0.54 per cent alumina, with the main minerals in the ore being amphibole (42 per cent), magnetite (39 per cent) and quartz (14 per cent). The concentrate obtained after low intensity magnetic separation contained 66.6 per cent iron and 6.34 per cent silica with an iron recovery of 72 per cent. This concentrate was further treated by reverse flotation to increase the iron content and reduce the silica content to meet the requirements for direct reduction iron (DRI) feed grade.

Jan 1, 1999

Possibilities for Flotation Acoustics Monitoring - A Review

Sep 13, 2010

The history of gold dredging in New Zealand, leading to the develop- ment of the `New Zealand Type' dredge is considered. Much of this infor- mation has come from contemporaneous publications by the New Zealand Department of Mines. Alluvial gold production declined after 1902, and ceased completely in 1982, but is now rising again. The progress of the New Zealand alluvial gold mining industry is considered, together with some of its more exceptional successes. Recent developments are com- pared to those of the past.

Jan 1, 1988

By R F. G Phelps, C J. S Sangster, G S. C

Narrow vein metalliferous mining in the UK has a long history, but there are only two small gold operations at present (Clogau and Gwynfynydd). Four further gold properties are at various stages of evaluation (Calliachar, Cononish, Curraghinalt and Maestryfer). The South Crofty tin mine closed earlier in the year. Narrow veins are exploited underground and are challenging to evaluate because of their geologically variable nature. They are generally less than 3 m wide, discordant, of variable dip (

Jan 1, 1998

This paper has been prepared to challenge the thinking of new leaders entering the mining industry in two areas. First, what is the worldÆs perception of mining and what does this mean to those entering the industry? Second, what is the future of learning in the mining industry and how can the industry attract and retain the best people?Then in closing, how can mining companies turn these challenges into opportunities and specifically how is BHP Billiton meeting these challenges.

Jan 1, 2004

Removal of Dilute Toxic Anions in Wastewater Using Aluminum Hydroxides Co-Precipitation Method

Sep 13, 2010

By Gerasimenko MP

The authors consider the features and advantages of a new promising trend in mineral processing - column flotation. Design aerohydrodynamic and process characteristics of pilot-scale columns are studied. Optimum process parameters for various ores and operations are studied. Flow patterns in cells of various cross-sections are investigated and the relationship between Peclet criterion and specific capacity of cell is determined. On this basis options were developed for optimisation of hydrodynamic characteristics of large capacity cells, including longitudinal sectionalising of the collection zone. It is shown that advantages of high column cells (10 - 13 m) produced in the West can be implemented in a sectionalised machine of smaller height (5 - 6 m). Investigations on the influence of slurry and air bubbles flow patterns indicated that to increase flotation rate of particles of various flotabilities it is expedient to combine co- and counter-current flows of phases in a single column. The proposed designs allow tailings to repeatedly return tailings to the collection zone and alternate co- and counter-current slurry and air flows. For the first time columns with alternating slurry flows (combination of co- and counter-current flows) are developed and commercialised. Unique multi-sectional cells having a number of essential advantages compared to monocells are developed. Design features of the cell allow: implementation of different flotation process flowsheets in a single unit, improved beneficiation process results, reduced specific power requirement, and elimination of sludging of the aerator and cell bottom part. Operational problems restricting introduction of column cells are connected with the aeration unit. The new cells are supplied with pneumohydraulic and stepped airlift spargers, allowing control of bubble size distribution with a service life of not less than three years. Successful operation of the new generation of columns with cell volumes of 15, 25, 40, and 80 cu m and the height of 5 - 6 m in copper, molybdenum, antimony, tungsten and nickel ores and coal slurry processing at different plants in this country illustrated their considerable process and operational advantages and verified the proposed options and relationships. A simulation technique of the flotation process and models for the solution of various problems are developed. A modular model of column flotation is constructed taking into account the kinetic relationship of the process and the hydrodynamic regime in the cell. Based on this, a technique of calculating the column parameters based on laboratory tests is developed (scaling-up), and applied for calculating the design of commercial-scale columns is developed.

Jan 1, 1993

This study examines the application of Landsat TM data to the identification of hydro- thermal alteration in the arid terrain of the El Salvador region of north Chile. Numerical reflectance values were extracted from the digital Landsat TM data for a variety of rock surfaces, including four parts of the El Salvador gossan, for each of six spectral bands. These reflectance values were analysed statistically in order to select the three spectral bands, combined as a colour composite image, that are most efficient in discriminating different varieties of alteration and for general geolog- ical interpretation. The most cost effective com- posite image for this area is a combination of bands 1,4 and 7 as the blue, green and red components respectively, with simple contrast enhancement. This image is superior to some much more expensive enhancement techniques and allows unambiguous identification of areas of hydrothermal alteration larger than about 50m. The display includes a practical guide to the use of Landsat TM imagery for volcanic gold Exploration.

Jan 1, 1987

By N Strong

Cracow is a high-grade; low-tonnage underground gold mine located approximately 500 km north-west of Brisbane in Central Queensland. It is a steeply dipping, narrow vein, epithermal gold and silver deposit that is accessed via a decline from surface. Cracow is owned by joint venture between Newcrest Mining (70 per cent) and Sedimentary Holdings (30 per cent). The orebodies are 5 m wide on average and the ore is extracted via sublevel open bench stoping. Stopes are extracted to a strike of approximately 25 m before being backfilled with waste. Prior to the introduction of electronics, the mine would remove a small amount of the previous backfill out to create a void, and then begin blasting two to three rings at a time, with the ore being extracted between each blast. This method caused the ore to be blasted onto the waste backfill resulting in dilution of the high-grade ore. It also meant that the extraction of each stope took a number of weeks and numerous blasting events. In the fourth quarter of 2005, the mine struck a geotechnically sensitive stope, where all 20 rings had to be extracted in a single shot or risk possible geotechnical problems that could sterilise the ore. Due to the limitations of NONEL« delay detonators the mine could not fire all the rings in a single shot and needed to use an electronic detonator system to extract the stope. Some unexpected benefits to the mine were increased fragmentation, reduced vibrations, reduced dilution, improved efficiency and improved hanging wall and footwall conditions. After the success of this first electronic shot, the mine has since moved to firing all their stopes with electronic detonators. With electronics the mine has been able to fire much larger blasts, and has in fact moved to firing their blasts in the opposite direction, firing towards the draw point instead of into the waste backfill, thus reducing ore dilution.

Jan 1, 2007

By M P. Schwarz

A major issue presently faced by companies producing and processing iron ore is the need to maximise throughput while minimising capital expenditure. While present high demand means this is of prime importance, the perennial issues of maintenance, operating costs, reliability, quality and environmental sustainability are also critical to profi tability. Attempts to address these issues generally require modifi cations to existing equipment, or trials of new equipment when designing plant for new projects.The risk involved can be substantially minimised by testing equipment improvements using advanced computational models prior to implementation. Examples of application of Computational Fluid Dynamics (CFD) and Discrete Element Method (DEM) modelling to sampling, cyclones, conveyor transfers, classifiers, dust control, banana screens, comminution and smelt-reduction will be given to illustrate the benefi ts of such an approach. *This is an abstract only. No paper was provided for this abstract.*

Jul 11, 2011

By K E. Barns, P J. Sharman, S A. Thomas and

This paper presents the development of a regrind facility design at BHP BillitonÆs Leinster Nickel Operations (LNO) in Western Australia. The recovery opportunity was identified from an analysis of plant operating data together with scanning electron microscope (SEM) measurements on relevant tailings streams from LNO. A laboratory procedure was developed to determine the potential recovery improvement of installing a regrind facility at LNO. The last step in formulating the process flow sheet and defining the process design criteria was to construct and operate a pilot plant, which incorporated four banks of flotation cells and an Xstrata M20 Isa Mill. Pilot plant on/off trials were used to define the expected metallurgical benefit. A prefeasibility engineering design and cost estimate was completed. Following a successful internal business evaluation, a feasibility study is currently underway.

Jan 1, 2007

This paper examines some of the important aspects of mineral taxation policies and practices, with reference to the mining tax regimes of selected Pacific Rim countries (see Tables 1 and 2). The following subjects are addressed:what is æmineral taxationÆ?, basis for mineral taxation, types of mineral taxes, objectives of the mineral taxation regime, best practices, and mineral royalties. Many countries, in some cases with the encouragement and assistance of international funding agencies, are actively assessing the international competitiveness of their mining tax regimes with a view to attracting investment. However, these countries recognise that the mining tax regime is not the only consideration that is taken into account by prospective investors. The countryÆs geological prospectivity, physical infrastructure, labour force, political risk, and regulatory system are also important factors in the investment decision making process. Although it is probably true that an attractive mining tax regime will not necessarily attract mineral investment, there is a real possibility that an unattractive regime can drive away investment. For example, Hugo Dummett, general manager for discovery at BHP, hinted recently that BHP could cease exploration in Russia in the absence of positive tax changes. Dummett is reported as saying that if taxes æend up being as onerous as they are now, we really have to rethink why we are hereÆ (Mining Journal, London, November 27, 1998).

Jan 1, 1999

The structure and tectonic setting has had a strong influence on gold mineralisation at the Porgera gold deposit. Here, the structural controls on the mineralisation at Porgera are discussed and placed in a regional tectonic context. The Porgera gold deposit is related to the emplacement of the Porgera Intrusive Complex. Prior to intrusive emplacement at Porgera,Papua New Guinea was affected by a major fold and thrust episode which occurred in response to arc-continent collision in the Late Miocene. After crustal shortening the region experienced a relaxation of compression which is expressed in the deformation accompanying mineralisation at Porgera. The first stage of mineralisation (stage I) is hosted by extension fractures, and is spatially associated with exposed intrusive stocks. A later episode of mineralisation (stage II) is hosted by the faults and fractures of the Roamane Fault Zone, which was active as a dip-slip normal fault during stage II mineralisation. Therefore a change in the tectonic environment from shortening to extensional tectonics can be seen at Porgera before and during mineralisation. Rapid fault-slip during stage II mineralisation may have aided high-grade gold mineralisation by subjecting hydrothermal fluids to changes in pressure, temperature, fluid-fluid and fluid-rock interaction. Uplift to form the highlands of Papua New Guinea occurred after mineralisation and was largely complete by 4.0 Ma.

Jan 1, 1995

By Firth B. A

The flotation of fine coal (minus 0.5 mm) often requires the addition of an insoluble hydrocarbon collector to apparently promote the adhesion of coal particles to air bubbles. A series of experiments was conducted using a radiotracer and narrow size fractions of clean coal to determine the effect of particle size distribution, collector addition rate, desliming of feed and emuIisification of collector on the distribution of collector between the different size fractions. The concentration of collector per gram of each size fraction was found to be approximately proportional to (average particle size)-2 except if the collector was emulsified prior to addition, the dependence altered to approximately (average particle size)-1. Mechanistic consequences are discussed.

Jan 1, 1982