Search Documents

Accident prevention in industry is a task as important to the ultimate result of an undertaking as efficient machines, good tools or trained operatives. In fact, like many qther phases of industry today, "Accident Prevention" or "Safety Organisation" has developed in this century, to a degree that is now acknowledged as an integral part of industrial thought and planning. This has not always been the case, as the following snap-shot picture of the past illustrates.The Broken Hill Proprietary Company recently celebrated at Whyalla the Jubilee of the opening of the Iron Knob Tramway. On that occasion a dinner was tendered to the pioneers, and in talking to the Writer of the early days one of the old gentlemen present could not refrain from recounting some of the accidents he had seen or experienced.Several such incidents were recounted at length, after each, the old fellow would say, "An' there weren't no safety officers or compensation in them days".The Broken Hill Proprietary Company Limited was a pioneer of safety in Australian industry and considerable success has followed its activity in this connection; the accident rate of the steel industry now compares satisfactorily with that of any other industrial undertaking. A measure of 'the success of the safety organisation, is, that in recent years, despite extensive construction programmes at various centres, and despite a heavy labour turnover, a decreasing accident rate has been maintained. This success, in the Writer's opinion, arises from the fact that by its early attention to plant protection, the introduction of safety standards and further through the interest and energy of departmental superintendents and foremen, the...

Jan 1, 1951

By Hebblewhite B, Humphreys D

An experimental mining project has been carried out in the Collie Basin to demonstrate the safe operation of total extraction mining techniques in the underground mines of the basin. To achieve this, it was necessary to design and install a means of controlling or removing groundwater so that goafing of the overlying strata could be safely achieved as part of the mining operation. The site chosen for the experiment was a triangular panel adjacent to Western No 6 (WD6) underground mine, which includes the 3 to 4 m thick Wyvern Seam beneath 130 to 180 m of overburden. The test area abuts a major fault on the downdip side. The overburden and underburden sequences include several horizons of permeable sandstones which form major aquifers. Water problems have long been recognized in all underground mines in the Collie Basin, and have previously prevented the successful application of total extraction mining. Following extensive hydrological investigations, dewatering and depressurization systems were designed to dewater the immediate roof aquifers and to depressurize aquifers higher in the sequence and in the floor. This would enable stable roof conditions to develop and controlled goafing to be achieved. The roof dewatering/depressurization procedure involved a combination of in-mine vertical roof drainage holes and conventional dewatering bores constructed from the ground surface above the mining trial area. The dewatering system was installed and operated for 29 months before the commencement of mining. Mining was eventually successfully completed in two trial panels using a retreat Wongawilli extraction system using bridge conveyors and continuous miners. Water inflow into the mine workings was channelled to a constructed sump area at the lowermost corner of the panel and pumped to the surface via vertical sump bores. The dewatering and depressurization measures adopted were successful in permitting the first controlled and systematic total extraction recovery of coal from the Collie Basin. This trial mining exercise demonstrated the potential for increasing substantially the recovery of coal from the Collie Basin, where previously recovery rates of around 30 percent from underground mining were commonplace, using only bord and pillar methods.

Jan 1, 1988

By McLennan R. G

The principle of personal safety is as old as the human race. The application of this principle to industry is of much more recent origin, and may be said to be almost exclusively the product of the twentieth century. The enormous strides in technique and production mode prior to the turn of the century had been achieved without any real regard for the crippled human by-products of that expansive era. It was accepted that. accidents were inevitable and formed part of the price that must be paid for production. It was not until 1885 that the first Workmen's Compensation Act was passed in Germany making the employer financially liable for injuries suffered on his plant.With awakening social conscience came the first organised efforts to reduce accidents in industry. Early 19th century literature dealing with the development of powerdriven machinery and the growth of industry in Europe contains many references to the unsafe and unhealthy working conditions that accompanied the change-over from the home workshop to the industrial plant. By the year 1900, there were in Germany - and a little later in England governmental regulations dealing with the guarding of hazardous machinery. American industry, now the acknowledged leader in industrial safety, admits freely that when an organised safety movement commenced in that country, there was already a considerable amount of information available to them from European experience. The steel industry was well to the fore in this work, and in...

Jan 1, 1957

By Luck D

Current methods of mucking out small development tunnels are a major limitation to improved efficiency and high rates of advance. This is particularly true in the deep metalliferous mines of South Africa, where the harsh environment, remoteness of operations and the hard abrasive rock conditions mitigate against the use of the tunnel borer type of equipment. The Loader Distributor Train was designed to overcome the special problems of hard rock tunnelling. It combines advanced innovative technology with proven simple methods of operation and maintenance. The system aims at taking advantage of new, efficient and cost effective power sources in South African mines based on replacing compressed air with electro hydraulics and the new concept of hydropower. It also introduces electronics and computer technology, for both automatic control and fault finding, into the production environment. The system is designed to permit sophisticated equipment to be operated and maintained by a semi skilled labour force. Although still undergoing trials it is believed that the Loader Distributor Train will prove highly effective, and that the new concepts offer considerable potential in areas other than flat tunnels, in particular the cleaning of inclined shafts.

Jan 1, 1986

The need to hoist increasing loads from great depths is leading to the more general adoption of winders of the Koepe and Blair types. The trend has introduced a number of new problems in winding ropes, more particularly in the Koepe system where regular destructive tests during the life of a rope are not possible. Consequently, the importance of introducing non-destructive tests is much greater, especially so in the case of Koepe ropes used for deep winding where there are three major destructive fatiguing influences. These are rotational effects when a vertical rope is changed end-for- end each trip, the much greater range of stress to which the rope is subjected each trip as compared with drum winding, and the destructive effect of a high coefficient of friction between wheel and rope. A plea for a lower coefficient in the interest of better rope and tread life, substantiated by analysis, is made for Koepe winders operating at depth.Co-ordination of rope testing with general hoisting problems is stressed and the active participation of the Wire Rope Committee of the Australian Mineral Industries Research Association Ltd. in the promotion ofthe project is noted.The general introduction of a rope testing programme in Australia, personnel requirements and some local basic research in the subject to cope with future demands are considered.

Jan 1, 1967

By Litvinenko V. I

Being a source of structural materials for many centuries, the modern image of the ferrous metallurgy is burdened with obsolete technologies with disregard towards new environmental protection requirements. The production cycle of metallurgical products have two clear-cut stages: I . production of liquid metal and casting into steel billets; and 2. processing of steel billets in solid state under high temperature to produce various shapes and profiles of metal products. Plastic deformation of metal at the second stage is least associated with environmental pollution and is presently being provided with more and more advanced equipment.

Jan 1, 1999

Caving is the lowest cost underground mining method, provided that drawpoint spacing, drawpoint size and ore handling facilities are designed to suit the caved material and that the drawpoint horizon can be maintained for the draw life. In the near future several open pit mines that produce in excess of 50 000 tons per day will have to examine the feasibility of converting to low cost, large scale underground operations. Several other large scale, low grade underground operations will experience major changes in their mining environments as large dropdowns are implemented. These changes demand a more realistic approach to mine planning than has occurred in the past, where existing operations have been projected to increased depths with little consideration of the change in mining environment that will occur. As economics force the consideration of underground mining of large, competent orebodies by low cost methods, the role of cave mining will have to be defined. In the past caving has generally been considered for rock masses that cave and fragment readily. The ability to define cavability and fragmentation, the availability of large, robust LHDs, a better understanding of draw control requirements, improved drilling equipment for secondary blasting and reliable cost data have shown that competent orebodies with coarse fragmentation can be exploited by cave mining at a much lower cost than with drill and blast Methods.

Jan 1, 1995

By M R. Lane, M L. Cramer, N P. Wines

Increasing attention is being focused by regulators and industry on the residual environmental liabilities associated with mining projects following site relinquishment (termed surrender in Queensland). Even sites that have been rehabilitated to a high standard and to the satisfaction of the regulator are not completely risk free and may require some degree of ongoing management. As well as ongoing monitoring and maintenance costs, considerations should include how costs associated with potential risk event occurrence can be quantified and, if considered material, how provisioning should be undertaken to minimise the risk to the state and to taxpayers. In Queensland for example, once a resource site is fully rehabilitated and meets its environmental authority conditions or rehabilitation completion criteria, the tenure and environmental authority can be surrendered. During the surrender process any ‘residual risks’ resulting from the use of the site for the resource activity must be considered, and, if requested, a payment given to the government to cover any ongoing management and risk costs. Accent Environmental, in conjunction with Lane Associates, was engaged by the Queensland Government as part of the government’s financial assurance framework reforms to develop an innovative, ‘one-size fits most’ Residual Risk Calculator for the Queensland resources industry. The calculator is an Excel-based tool that uses detailed user inputs to estimate post-surrender management requirements and liability at resource sites. If residual environmental risks associated with rehabilitated mine sites can be identified, quantified and managed through pragmatic regulatory tools and effective provisioning, site relinquishment/surrender can be achieved without compromising environmental and social outcomes or exposing the state to unreasonable financial risk. The effective management of residual risk can also help facilitate operations as well as relinquishment/surrender of sites where a ‘walkaway’ solution may not be otherwise technically feasible.

Aug 2, 2023

By Heyer T, Wasmuth H-D

The concentrator plant of Fahrica Mine, that started production in 1977, was using nine Jones wet high intensity magnetic separators (WHIMS) of the standard type DP 317 with a 1.5 mm gap width for the production of pelletfeed concentrate. These WHIMS units were operating in parallel with a feed rate of 110 t per hour, with about 47 per cent Fe in the feed, and with a maximum of only 0.8 per cent magnetite. The field strength was about 1.2 Tesla. From 1986, the mine has adapted its production facilities to mine and concentrate larger amounts of lowgrade itabintes to maximise the use of the available iron ore reserves. An increase of up to three per cent magnetite in the magnetic separator feed, resulted in a reduction of capacity. This was due to partial clogging of the separation boxes at high field intensities, which were required for the recovery of the very fine hematite. Even by lowering the feed rate and the field intensity the problem could not be resolved. After extensive testwork in a pilot plant, with a Jones separator model DI' 90, the commercial WHIMS plant was modified into a two stage process using the existing nine Jones separators. The gap of the first stage with four machines was increased to a width of 3.5 mm, corresponding to a maximum field intensity of 0.7 Tesla. This first 'medium intensity scalping stage' is followed by a second 'real' high intensity WHIMS step with five machines operating at the original settings with 1.5 mm gap width and 1.0 Testa maximum field intensity. Feed rates of up to 320 tons per hour in the first and up to 240 tons per hour in the second stage could be achieved. The design concept of the concentrator at Fabrica mine is described using the old and new flowsheets. Details of the pilot plant testwork as well as actual performance data of the new plant section are presented.

Jan 1, 1993

The importance of the minerals industry to any economy is clearly demonstrable. Its raw materials and products are the foundation of modem society and they have shaped the history of mankind from prehistoric times to the space age of today. However, those in the minerals industry have clearly failed to impress this fact on the consciousness of the public, bureaucrats and politicians. They have also failed to engage their dedicated opponents in a constructive debate. This is mainly because the minerals industry has been unwilling (until recently) to deal with the "soft" issues of civil society, nor understand and operate on a more emotional level. Technical professionals (as well as managers) in the future must be as comfortable in handling community concerns over social, environmental or landowner issues, as they are with logging complex drill core, designing blast patterns and separating one mineral from another. They must become caring, effective communicators and mediators. These are the new skills of a professional in the Third Millennium. These issues are outlined and discussed with some Australian data used to illustrate the point. If there is to be a future for all, then the policy makers within all levels of government (national, regional or local) must not drive essential mineral development offshore. They must address ways to support wealth creation mechanisms, particularly innovation. The minerals industry is a powerful wealth creator for ordinary citizens and an innovator. Politicians and their advisers must not .be allowed to forget this fact. If the ANZAC minerals industries do not win the emotional debate and successfully deal with the "soft" issues as well as they deal with the technical issues, there can be only a dim future ahead.

Jan 1, 2000

By W Valery, A Jankovic

The ball mill in closed circuit with hydrocyclones is an industry standard, and well known methodologies exist for equipment sizing, selection and design. However, the potential to improve the capacity of ball mill circuits by replacing cyclones with screens has been recognised for many years and recently has been successfully realised, thanks to developments in fine screening technology. Proper methodology for equipment sizing and selection is required to capitalise on this opportunity, but there is currently insufficient information and few guidelines available on how to design such a circuit. This paper discusses the differences between ball mill circuits closed with cyclones and with screens. A methodology is described for equipment sizing and selection for a circuit closed with screens, and the laboratory testing requirements are described for low grade base metal ores and magnetite ores. An economic evaluation is also presented for a case study demonstrating the potential benefits of closing a ball mill circuit with screens.CITATION:Jankovic, A and Valery, W, 2013. Energy efficient ball mill circuit - Equipment sizing considerations, in Proceedings MetPlant 2013 , pp 285-295 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

Silver is one of the three major metals produced from the Broken Hill mines. The accurate determination of the silver in these ores, therefore, is of economic importance.With due appreciation of the divergence of opinion of many who are interested in the subject of the determination of silver, the writer has been prompted to present the results of some recent experiments on silver losses during cupellation and conclusions from these experiments in the present paper. The losses of silver in the fire assay for this metal are due to silver retained in the slag during the fusion or scorification of the ore, and to silver volatilized from, and absorbed by the cupel during the process of cupellation.The literature describing the results of experimental work on silver losses due to the above causes is extensive, and the general conclusion of these experiments is that the silver lost in the slag is small, but that lost by cupellation is larger and more variable.The term cupellation loss in this paper refers to the total cupellation loss, no distinction being made between the absorption and volatilization losses.Volatilization loss is shown by King to be 0.5% of the total cupellation loss and, as it is generally accepted among assayers as being only a small fraction of the cupellation loss (3) (5), it will not receive further consideration in this paper.The factors causing the loss of silver by cupellation and the precautions to be obs~rved to reduce the loss in this operation are described in (1), (2), (3), (4) and (5). The...

Jan 1, 1940

By Moinpour M

The kinetics of reduction of copper (cuprous) sulphide with CO-CO2-He gas mixtures, using an excess of CaO(s) as a sulphur-scavenging substance were investigated in the temperature range 855° - 950°C by a thermogravimetric method. Several gas compositions were employed at each temperature. Potential carbon deposition was overcome by preheating the reducing gas mixture. The phase-composition and the morphology of partially reactedsamples were analysed by a SEMlEDAX unit. The reduction rates showed strong dependence on the bulk gas compositions (CO, CO2) and, in most cases, the rate declined with rising temperature. The rate-controlling step appears to be the diffusion of CO2 gaseous species through the micropores of the CaS(s) - product layer which builds up around the CaOcore.

Jan 1, 1989

By Freeman NV

The concept of an in stream analysis probe was developed at The Zinc Corporation (now Z.C. Mines) in the late 1960's and commercialised quite rapidly, by Phillips and then AMDEL, as an alternative to the established centralised systems (Courier, etc.). The developments which have taken place since that time are reviewed and current procedures and performance are described. An audit of the system, recently undertaken by AMDEL, has highlighted areas where improvements can be made. In 1988 the ISA system will become an integral part of a substantially upgraded process control system.

Jan 1, 1988

By B R. Olsson, N Marinopoulos

To establish the design and the capacity of the Stanwell Magnesium Plant, Australian Magnesium Corporation Ltd (AMC) with Fluor Australia has modelled the operation of the magnesium plant using ARENA Simulation Modelling. The reliability model has been used to evaluate: surge capacities required between different sections of the plant; critical equipment requiring standby capacity; the number of trains required for different sections of the plant; and potential capital cost reduction options. The reliability model was established using the detailed Process Flow Diagrams, reliability information from literature and maintenance, operation and start-up experience from the Demonstration Plant. The model was run with different plant configurations to assist AMC in determining the most effective configuration to provide the production capacity at the lowest capital cost. The model was not only able to confirm the plant capacity to the independent technical expert but was able to minimise quantitative risk by minimising the quantities of hazardous materials on site. Fluor Australia provided the ARENA simulation expertise and has used this software for optimising new plant design and to establish improvements in operating plants. Reliability modelling is a normal feature of chemical plant design but is rarely used in the resource industry. The experience gained by AMC in the modelling system has indicated that metallurgical plant design can be improved by the application of reliability modelling.

Jan 1, 2002

By G Metzner, R Rodriguez, C Savage

OK Tedi Mining Ltd. (OTML) is in the process of optimising the concentrator performance. One aspect that has been recently implemented is an upgrade of the existing expert control philosophy on the grinding circuit and this will be the topic of this paper. Ore grinding in SAG mills is a multi-input multi-output (MIMO) process subject to several disturbances, most typical being quick acting disturbances such as changes in ore characteristics like hardness and particle size and slow acting disturbances such as ball charge variations and liner wear. The OTML SAG mills treat ore from diverse ore bodies and receive fresh feed subject to large changes in particle size. These circumstances make these mills particularly challenging to control. In this paper, a comparative analysis is presented between the performance of the OTML SAG mill #2 before and after the commissioning of a hybrid control strategy. The strategy uses Expert Knowledge combined with advanced disturbance rejection to reduce the variability of the main process variables, especially pressure and power. It further optimises the overall operation by driving the SAG mill #2 against process constraints (e.g. high power, high motor temperature and high scats recycle rate) and maintaining the operation at or near this point. This strategy is implemented by a combination of the manipulated variables (i.e. fresh feed tonnage and % solids) at any given time.The paper will present trends and a statistical analysis of the comparative results of the mill operation over a period of months, showing a 30% reduction in mill power / pressure variability and a 12% improvement in average power drawn. An increase in throughput was also observed, but cannot be conclusively attributed to the change in mill control due to other changes that were made to the SAG mill #2 during the period of comparison. An additional benefit includes better acceptance from the operators with improved consistency of the SAG mill #2 operation across shifts.The paper will also discuss further improvements envisaged in the continued optimisation of the grinding control circuit.CITATION:Savage, C, Rodriguez, R and Metzner, G, 2013. Hybrid process control strategy for the Ok Tedi Mining Ltd semi-autogenous grinding mill #2 - A comparative analysis, in Proceedings MetPlant 2013 , pp 202-214 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 15, 2013

All previous attempts to cut rock in boring by means of revolving steel cutters have failed, chiefly in consequence of the mis-shapen teeth grinding the rock and themselves simultaneously, until, after a very few revolutions, the points of the cutters were so worn that it was impossible to force them into the strata. The diamond drilling plant being cumbrous, complicated, and costly, and seeing that fully 70 per cent of the boring generally needed is in what is known as the" milder strata," it will be readily understood that much of the work done will not pay a dividend on the outlay, so great is the cost of removal, the wear and tear of the machinery, and the loss of diamonds. The Calyx Drill, however, invented by Mr. F. Harley Davis, has been constructed so as to overcome these difficulties, and will penetrate quickly and .at a low cost this 70 per cent. of the milder strata. The Drill has taken ten years' hard work and thought to bring it to its present state of perfection, and it will now drill with steel cutters the 70 per cent of the work performed by the diamond drills at a greater speed and at about one third the cost of the latter.The utility of the diamond drill for certain work is undeniable, but it cannot by any means be described as a machine of general popular usefulness that is to say, it is quite beyond the reach of the great masses of mankind.

By R Cowen

Past successes of low impact mineral exploration and rehabilitation of mined areas in developed land of subdued contour provide little guidance for similar activity in more sensitive high country or mountain environments. Land management agencies and environmental pressure groups have expressed considerable concern about mineral development in these areas by land especially where the land involved has high environmental or productive values. Mineral explorers are responding with detailed proposals for integration of environmental assessment and mineral exploration at an early stage. A model programme for Fiordland National Park presented in this paper illustrates this approach.

Jan 1, 1981

New Bio-Adsorber with Activated Carbon and Nano Tube Carbon for Separation of Nickel and Cadmium

Sep 13, 2010

Judicious placement of a range of geotechnical instruments was employed at the Tasmania gold mine, Beaconsfield, Tasmania, as a key strategy in the monitoring of rock mass conditions over the past four years. The range of instruments employed included vibrating wire stress-meters and hollow inclusion cells to monitor changing stress conditions, resistance wire and multipoint borehole extensometers to monitor the impact of stress changes on the integrity of the rock mass, and instrumented cable bolts and threadbar bolts to monitor the static and dynamic impact of rock mass changes on the installed ground control system. Initially the monitoring was of a qualitative nature, monitoring change from the time of installation. The value of the output was considerable when considered in relation to the ongoing seismic record which was also being monitored. It was clear from the seismic record and the monitoring results that stope blasting was the primary trigger for changing rock mass conditions. However, it was unclear how well observed behaviour was reflecting conditions anticipated by elastic numerical modelling. The latter had predicted significant stress increase in the near field of man-access footwall development. Qualitative monitoring and visual inspection did not support the modelling prediction, and this led to a program of quantitative measurement being undertaken. Measurement of the absolute stress condition in the backs of footwall development immediately adjacent to monitoring hollow inclusion cells provided the benchmark for tracking quantitative stress change. The program provided insight into the evolution of principal stress field magnitude and orientation in relation to rock mass change observed with extensometers and instrumented ground control elements, as well as providing a degree of calibration between the elastic numerical modelling and the virgin stress field. Calibrated monitoring data has also provided a useful benchmark for finite element modelling which is to be used for future mine-wide design.

Nov 25, 2010