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By Smith P

The past 20 years have seen the replacement of hydraulic control of longwall mining systems by the neater. smaller and better controlled electronic units.Early problems of moisture and other effects on reliability were overcome to see electronically controlled supports chosen for Corrimal Colliery ten years ago. Lessons from Corrimal and elsewhere, with following improvements and sophistication led to wider use as exemplified by Meco and other electronically controlled supports used in more recent installations in New South Wales, Queensland, USA and Czechoslovakia of the total of over 80 electronically controlled support installations worldwide in the past decade. Present work is toward a fully "integrated face" of British Coal by 1993, incorporating the Meco automatic face straightening system already due for practical use in the UK later this year. However the manless face still appears to be some way off although the present minimum crews and close monitoring, including early warning, are promising stages.

Jan 1, 1991

By Scaife PH, Cripps Clark J, Cameron DB

Tuyere coke samples have been taken through the tuyere openings of B.H.P. International Blast Furnaces since 1978 with Whyalla No. 2 Blast Furnace taking samples on a regular basis since 1982. The degradation of coke during it's passage through the Blast Furnace can be measured and the relationships between these data, feed coke data and blast furnace operating data demonstrated. Tuyere coke sampling has been useful in revealing misleading external coke testing results and is still the method to monitor directly the performance of coke within the Blast Furnace.

Jan 1, 1987

In the last two decades, equipment used in the coal mining operations has become much more sophisticated. The way that work is organised and performed in the industry has also changed significantly. Changes in equipment specification or procedures inevitably means that the risk associated with that equipment or procedure also changes. In an attempt to address this the Joint Coal Board Occupational Health and Safety Trust (JCB) commissioned the University of New South Wales Mining Research Centre and Mine Site Technologies to perform a feasibility study into the development and deployment of Virtual Reality (VR) based training simulators in the New South Wales coal industry. The main aims of the study were to identify, the key providers of VR Technology, the VR options available to the JCB and the information that would need to be included in any simulator. It was anticipated that a critical assessment of these components would produce a format for a cost effective, state of the art simulator that could be readily accessed by all mines. The expectations of the feasibility study were that VR should offer three-dimensional (3D) simulations that are interactive, high-resolution models of real environments based on best practice Safety Management Plans. It was anticipated that the simulations would allow trainees to experience the consequences of poor decision-making and allow them to learn from their mistakes in a safe and forgiving environment. It was envisaged that such simulators would become an addition to the existing training methods used in the industry.

Jan 1, 2003

Sluice-boxes are by far the most widely used concentrating devices by small-scale operators in PNG who work alluvial gold deposits. The sluice-box designs and their operating conditions used are known to vary widely. The selection of sluice-box configuration and the operating parameters such as the water flow rate is purely based on past experience. Some use small flowrates to increase the fine gold recovery at the expense of efficient separations and capacity while others use high flow rates resulting in increased fine gold losses but with high throughput rates. Recent work has revealed that the combination of riffle height, their spacing and wash water flow rate are the most important parameters that determine the success or failure of such operations. This combination has been shown to depend on the in situ gold and gangue size distributions of the deposit being processed. This paper describes a design procedure which uses a non-linear optimisation method to determine the optimal combination of the above parameters to maximise the metallurgical efficiency of such operations.

Jan 1, 1993

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

Spiral separators have been used to treat heavy mineralsands in Australia for some 35 years. During the last five years the logical extension of this technology has been torecover cassiterite from alluvial deposits. Plants incorporating spirals are already operating in Indonesian andAustralian tin mines. A more fundamental understanding of the design of spiral separators has recently led to their use in other mineral treatment plants.In particular, the treatment of alluvial gold and fine coal has been most successful. The new generation of spirals that has been developed to treat these minerals is more easily operated than other competing processes and is therefore ideal for new mine situations.

Jan 1, 1986

By M Pizey

After 60 years of operation, coal extraction at Solid Energy New ZealandÆs (SENZ) Strongman Mine, near Rapahoe is scheduled to end in early 2005. Up until 2003 the closure bond for Strongman Mine was only $930, and both SENZ and the West Coast Regional Council (WCRC) agreed that a more realistic level of bonding was required.   A conceptual closure plan has been developed by Golder Associates, and the cost of the work estimated. Closure includes decommissioning of equipment and facilities, rehabilitation and replanting of all disturbed areas and a period of maintenance and monitoring to verify that closure objectives have been met. Significant maintenance allowances are included to cover management of underground fire, subsidence and slope instability. These make up much of the potential ongoing environmental liability at the Strongman. All costs incurred beyond year 1 of closure are discounted to present value. Uncertainty in costs is addressed by Monte Carlo simulation, with an 80 % confidence level adopted.   A bond quantum of $3.0 million has been calculated for the first year of closure at Strongman. A three-year ærollingÆ bond is proposed. Progress will be reviewed annually, with the bond adjusted up or down accordingly. It is then renewed for a further three years. This allows for progressive return of the bond as rehabilitation objectives are met and verified. Similarly, if there are delays in meeting objectives, a proportion of the bond may need to be kept in place for a longer period than assumed. The level of bonding in place for the Strongman operation at any time in the future will therefore reflect the cost to complete the closure work programme.

Jan 1, 2004

By Smith IEM

Some samples from arc-type volcanic suites collected in northern New Zealand and southeastern Papua New Guinea show rare earth element (REE) and Y abundances which are enriched relative to the those typical of their respective associations. This enrichment appears to be the result of an alteration process which selectively mobilises the REE and re-precipitates them as REE-bearing minerals in veins and interstitial patches. The alteration is on a micron scale and is not detected in routine petrographic examination. The spectre of REE mobility in young apparently fresh rocks is important to igneous geochemists who use REE abundances to constrain petrogenetic models and may also be important because it indicates the operation of a natural REE enrichment process which could operate in the formation of economic REE deposits.

Jan 1, 1990

By Y V. Haarlem, P Coghill, N G. Cutmore, M Millen, I Carter

Due to the low concentration of gold, ore sorting for gold has always required measuring indirect properties, such as density or colour, to allow separation on a rock by rock basis. This only works on an ad hoc, by deposit basis and is likely to be least reliable where it is most required in low grade ores. One candidate technique, Gamma Activation Analysis (GAA) has been demonstrated to directly measure gold extremely accurately in powder samples of around 500gm and is used in the Chrysos PhotonAssay assay system. This method uses a linear accelerator (linac) to generate the X-ray radiation that activates the ore at low levels to emit a characteristic gold gamma ray that is then measured by a radiation detector. CSIRO is adapting this measurement technique to application on a belt at up to 800tph to measure pods of ore. The principal differences between measuring samples and an on-line measurement of pods are the requirement to measure coarse ore (<50mm), to measure a larger volume of ore as uniformly as possible, and to have an open-ended geometry with adequate shielding of the linac radiation source. These issues have all been addressed with measurements of coarse ore reported down to around 1ppm in sub-optimal test conditions. They have been demonstrated for <75mm particles with detectors capable of measuring a large volume geometry continuously. These are projected to allow measurements down to 0.3ppm in more optimum conditions for a 10 second measurement time period where the U/Th content of the ore is less than ~10ppm. Extensive Monte Carlo modelling has demonstrated that adequate shielding can be provided in relatively simple geometries with only 1 right angle transfer in the material handling. Steady progress is being made to reach the technical position required to trial an ore sorting system.

Nov 10, 2020

By Forssberg KSE

Purification of GAsgruvan Limestone is carried out by anionic, cationic and cationic followed by anionic flotations in order to obtain a calcite concentrate that is acceptable to the paper industry. The results indicate that such a concentrate could be achieved by first carrying out the separation of siliceous gangue minerals by cationic flotation followed by the separation of carbonate during the anionic flotation. Stearylamine acetate (Flotigam SA) and a modified fatty acid (OMC 357) are found to be selective during cationic and anionic flotation, respectively. A final product containing 99.25 per cent calcite with a recovery of around 80 per cent is obtained. It is hoped that these results could be further improved by the follow-up process variable studies, in particular, the effect of reagent dosages and conditioning time at each stage of cationic and anionic flotation steps.

Jan 1, 1993

By J R. Manuel, M J. Peterson

Selected drill core samples from a Ferrobamba-limestone-hosted, magnetite-haematite skarn deposit, located in the Apurimac department of the Andahuaylas-Yauri skarn/porphyry belt of south-eastern Peru, were mineralogically and texturally characterised to gain a preliminary indication of the deposit&apos;s potential as an iron ore resource. Optical microscopy, X-ray diffraction (XRD) and scanning electron microscopy/electron probe microanalysis (SEM/EPMA) techniques were utilised to determine the characteristics of magnetite, haematite and/or goethite dominated ore types, including variations in the relative proportions and textural relationships of the ore and gangue minerals. The deportment of elements deleterious to processing performance (eg copper, sulfur and potassium) was determined and the beneficiation potential of the samples was briefly assessed. In drill core sections, the ores are grey to reddish in colour, massive and &apos;metallic&apos; to dark brown and earthy in character, moderately hard and porous (macro and microporous), with variable gangue infill. Ores often appear weathered, typified by ochreous goethite staining and common minor goethite (except in dense core fragments), occasionally exhibiting a more friable texture with coarse magnetite/martite grains. Silicates and lesser carbonate gangue are visible as blue-green to beige to white scaly and/or shaly surface coatings, and finely particulate infill, often goethite stained. Sulfide-rich ore types also occur in part of the deposit, but are restricted to specific drill holes. Magnetite grain size is relatively coarse, compared with magnetite from typical banded iron formations, whereas discrete silicate gangue is mainly bladed/fibrous and/or layered and micaceous in form. XRD analysis indicates the presence of vermiculite, serpentine, stilpnomelane, chlorite, actinolite and clays. There is a spectrum of ore types representing the gradation from &apos;fresh&apos; (magnetite-dominated) to oxidised and weathered (martite/goethite-dominated). Martite-dominated samples are generally higher in grade, due to leaching and removal of silicate gangue, resulting in higher macroporosity. Where gangue has been leached out, partial replacement by vitreous goethite and/or hydrohaematite is typical, often preserving the fibrous/layered characteristics of the original silicates.

Jan 1, 2009

Prior to the merger of BHP and Billiton, both companies had a keenfocus on improving their performance in health, safety, environment and community (HSEC) matters. This shared intent, albeit executed insomewhat different ways, provided an excellent foundation for the newCompany. During the integration planning phase, a team was formed toconsider the organisational design for consistently achieving world class HSEC performance. The design included the policy platform, resources, structures, standards and procedures to be implemented in the merged entity. A key aspect of the design was the fully integrated HSECManagement Standards. These Standards create the framework for theconsistent application of BHP BillitonÆs HSEC Policy at all of ourmanaged operations across the world. The Standards have their origin in similar frameworks adopted by BHP during the 1990s, as well as thewell-known quality related standards (eg ISO 14001). However, they areunique in that they combine all aspects of HSEC management into asingle integrated set of auditable standards. By combining these areas and integrating our HSEC Management Standards with other aspects of the æBHP Billiton WayÆ, we are establishing a holistic, line management driven improvement approach. Over time, the BHP Billiton Way will embed a systematic improvement philosophy that we expect will become a key source of competitive advantage. The HSEC Management Standards are consistent with ISO 14001,OHSAS 18001, the Australian Minerals Industry Code for EnvironmentalManagement and generally aligned with SA8000. While compliance withthese external standards ensures that a systematic approach andimprovement plans are in place, BHP BillitonÆs HSEC Standards gofurther to include minimum performance requirements that reflect theintent of our HSEC Policy. Therefore, implementation at site levelensures that robust systems are in place to implement our Policy and that accreditation can be achieved to external standards if required.To assess implementation of the HSEC Management Standards anaudit system has been designed which incorporates both self-assessmentand peer review. Each site is required to undertake an annualself-assessment of compliance with the Standards using a commonassessment protocol. Every three years a peer review is conducted at each site to confirm the results of self-assessment and to provide a means of sharing knowledge throughout the Company. The review teams are composed of line managers and HSEC professionals from around theCompany, representatives of our joint venture partners and independentspecialists as required. The Company has committed to public reportingof the audit results through our annual HSEC report and this is reflected in our published targets. From a wider perspective, as we in the resources industry strive tocollectively raise our HSEC performance and reputation, there may be arole for industry based HSEC Management Standards complemented bya level of independent review.

Jan 1, 2002

Although the last decade has seen the growth of many new licencing and approval requirements for the exploration and mining industries, there remains in each State of Australia and the Northern Territory a predominant "Mining Act" containing provisions for the grant of exploration and mining tenements. What then are the rights and duties of tenement holders either by virtue of a Mining Act or through other approval and licencing mechanisms? What rights and duties does a person acquire when he is granted an exploration licence or a mining lease? In this paper I will attempt to cover these types of questions using in particular examples from New South Wales. I will also refer to a range of other subordinate approvals and licences which today&apos;s society requires and the need for ethics and recognition of liabilities.

Jan 1, 1995

The changing characteristics of raw materials has highlighted the limitations that conventional vibrating screens have in the handling of fine wet sticky materials. These&apos; limitations have led to the development of a totally new concept of screening, the Rotating Probability Screen. In order to illustrate the practical benefits to be gained by the extraction of fine materials ahead of subse quent processes particularly in the coal industry, the experiences gained in Ro-Pro installations in America, Australia, Europe and Britain are drawn upon.

Jan 1, 1984

By Dunne R. C

Column flotation is receiving increased interest from both an industrial and research perspective in Australia. The traditional overseas application as a molybdenum cleaning cell is being expanded and a number of new applications as cleaners, scavengers and roughers are emerging in Australia. The success of column flotation has hinged on the new understanding developing from the work of Finch- and coworkers at McGill University, Canada, particularly in relation to scale-up parameters and model development. The aspiring column flotation user in Australia now a has wealth of experience to draw on when deciding on the correct procedure to follow during the process evaluation and plant installation stages of development. However, some aspects relating to column design, such as aeration mechanisms, require careful evaluation.

Jan 1, 1987

By Yang RL, Bailey ML

During overburden blasting operations in dragline pits, coal edge losses along the lowwall edge of the new pit are often experienced. In tonnage terms, losses can be significant. With the thick seams at Callide Mine, 20,000 tonnes of coal can be lost along a 600 metre pit. In addition to the immediate dollar value of the coal, replacement of this coal (from which overburden has been removed) will be from higher ratio and higher cost pits in the future. Unit costs of production for the remainder of the coal uncovered in the current pit increase. Experiments involving variation of blasthole inclination and/or amount of standoff on the front row of blastholes have given no significant improvement in the coal edge loss control.

Jan 1, 1988

The Savage River Mines concentrator and pipeline has operated for seven years. During this time some problems of general interest have been overcome, particularly in the area of autogenous grinding in large mills and in pump- ing solids over long distances. The plant flow sheet and equipment at Savage River and the control techniques are. described. Ore type has varied widely over the per- iod of plant operation. Techniques developed to minimise the effect of variations on through- put are discussed&apos;. The main technique is the controlled rejection or addition of grinding Media.

Jan 1, 1975

A thousand writers have harped upon the wondrous nature of the inventive faculty. They realise that man is a creator, and that capital and labour alike are, and will always be impotent without machinery and processes that is invention. What Bacon has said is echoed by them all, "the introduction of new inventions seemeth to be the very chiefest of human actions. The benefit of new inventions may extend to all mankind-they make all men happy without injury to &apos;any&apos; they are new creations and imitations of God&apos;s own works." My remarks will occupy another field I will refer to some of those features of the Patent Laws of different countries, which prevent the use of new inventions, oppress the development or inventive&apos; genius, and diminish human happiness and progress&apos; Wherever Patent Laws are framed and administered upon wrong principles, these results are inevitably found. A concise, complete, common-sense comparison of the chief Patent Laws of the world cannot easily be found but to avoid seeing scrappy, misleading references to Patent Law in the press particularly the English-would be equally difficult. Writers who are considered authorities so frequently make minor issues prominent and so uniformly fail to give weight to fundamental principles that the effect on the public is to mislead.

The comminution process indicates that the most energy-efficient comminution system would be one where the particles leave the breakage field as soon as they reach product size. Contrary to the free falling gravitational (vertical) flow in crushers, the grinding millÆs energy efficiency essentially depends on ore characteristics and the discharge rate of broken particles, which in turn depends on how efficiently the discharge pump (grate and pulp lifters) operates. The essential function of a pulp lifter is to transport the broken material and slurry from the discharge grate out of the mill. Hence, the design optimisation of pulp lifters affects not only the energy efficiency and throughput of autogenous grinding/semi-autogenous (AG/SAG) grinding mills, but also contributes other process benefits such as improved wear life and operator-friendly steady and smooth mill operation. Following its introduction in 2006, OutotecÆs patented Turbo Pulp Lifter (TPLÖ) design has been retrofitted at existing sites and also installed in some new ones around the world. This paper will provide operational experience and data on how the TPLÖ design has allowed AG and SAG mills to operate efficiently.

Jan 1, 2009

Reserves of high-grade quartz gravel, lignite, and timber suitable for the production of silicon metal and ferrosilicon on large scale occur within 40 miles of Bluff Harbour. Undeveloped hydroelectric power resources on the Clutha River are located within 50 miles of the most promising quartz gravel deposits while opencastable lignite, potentially suitable for electric power production, occurs in the same locality as the quartz gravels. A preliminary study of production economics indicates that the commercial feasibility of silicon/ferrosilicon production would depend mainly on the cost of electric power, total capital cost of plant, and the market value of the products. The proximity of Bluff Harbour is advantageous for the export of products.

Jan 1, 1971