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By P Andrieux

By 1996 ground control-related problems at Brunswick Mine had raised serious concerns regarding the safe and economical extraction of large portions of the reserves. These difficulties were mainly caused by high stress levels in pillars, instabilities resulting from wide spans supported by ageing support elements, and chronic difficulties supplying rock fill from the surface quarry to the underground workings, which resulted in many large voids remaining open for long periods of time. Significant changes have been implemented at the site since 1996, amongst which were a change of mining method, the introduction of paste backfill, the establishment of stress management measures, and the introduction of shotcrete on a large-scale. This paper focuses on the regional ground conditions associated with both the previously used primary-secondary mining method and the newly implemented pyramidal pillarless technique, as well as on some of the stress management measures implemented at the mine.

Jan 1, 2000

By Merry N, Cocks T

The mineral exploration industry is increasingly aware of the importance of the relationship between mineralogical data and geochemical assay results. However, until recently, the cost and time constraints of most techniques for analysing alteration mineralogy have precluded detailed alteration studies. These impediments have been reduced by the development of the Portable Infrared Mineral Analyser (PIMA), a field portable infrared spectrometer that allows rapid (in field) and cost effective analysis of alteration minerals including subtle variations in mineral crystallinity and Composition.

Jan 1, 1995

By Sims D. A

This paper primarily describes the application of geology to the different mining methods employed in a large underground mine. The steeply dipping stratiform Silver/Lead/Zinc mineralisation at Mount Isa include up to 28 mineable orebodies. The orebodiea are mined by cut and fill, sublevel benching and sublevel open stoping; the method chosen depending mainly on orebody geomechanics.The sources and methods of data collection, and the interpretation process undertaken, are described. The paper emphasises the different geological input required, by each individual mining method, to provide the necessary production and strata control. This input contributes significantly to the success and efficiency of the operations.

Jan 1, 1990

This paper briefly discusses the negotia- tion of the more important provisions in agree- ments for exploration and mining rights with Pacific countries. LAND RIGHTS Land rights are complicated and sometimes controversial in many of the Pacific countries. In some countries, a company will have to deal with land owners directly; in others, the government will act as intermediary. Inevit- ably, a company will have to deal with both. Mining companies need to be sensitive to the culture and particular interests of the land owners and of their history in defending their rights. The issues are too complicated to be dealt with here. Some mining companies have spent, and will continue to spend, considerable time trying to understand them. It will " require patience, perseverance, sensitivity and unflagging optimism. The better advised companies will ensure that their local repre- sentatives get to know the land owners, under- stand their concerns, and will pursue a policy of keeping them informed on a regular basis of all of the company's activities and proposed activities. Good community relations are the keystone for good mining operations in the Pacific. Most countries will require the submission of an environmental impact statement so that they will know in advance what effects a pro- posted mining operation are expected to have on the environment and how it is intended to deal with them. They will also want to approve the company's environmental reclamation and rehabilitation plan. Let's face facts right away - mining, by its very nature, is not going to improve the environment. There will be waste discharges, emissions and deposits. They will affect the land, air and water and hence human, marine and animal life and vegetation. There will be sounds and odours and the esthetics of mining operations, though perhaps pleasing to geolo- gists and mining engineers, will not please Others.

Jan 1, 1987

Historically BHP Billiton Alliance Coal Operations Pty Ltd (BMA) have generated resource models from widely spaced data points (drill holes). The accuracy of these models has been influenced by the degree of local structural disturbance of the coal seams and by the choice of interpolators used in the modelling process. In some circumstances unacceptable vertical errors of up to 10 m have been observed whilst mining. New terrestrial photogrammetry or laser imaging technology now allow the 150 or so kilometres of exposed highwalls in BMA to be rapidly, accurately and safely mapped and the three-dimensional images economically incorporated into resource models, reconciliation grade control models, drill and blast designs and for pit stability analysis.

Jan 1, 2005

By Kleine T. H

Blast design involves many engineering constraints and objectives. Some of the more important include the implementation costs, the desired fragmentation and shape of the muckpile. A spreadsheet has been developed to allow blast design options such as burden, spacing, blast hole diameter, decking and explosive type to be varied. As any option is varied the spreadsheet recalculates and graphs the expected implementation costs, fragmentation and muckpile shape in seconds.The spreadsheet extends the philosophy of simple robust fragmentation prediction (Cunningham, 1983) to include similar models for explosive detonation (with respect to explosive type, age, blast hole diameter and density) and muckpile shape (with respect to burden, spacing, charge location and weight). The new empirical models for explosive detonation and muckpile shape prediction have been calibrated successfully for one situation and are now undergoing further field trials.

Jan 1, 1992

The ore deposits of the Oobar mining field are confined to sediments of the Early Devonian Cobar Supergroup. The mineralisation is discordant to bedding and parallel to cleavage. The structural association is variable with the deposits near the eastern margin of the Cobar Basin formed in zones of deformation and faulting. The Elura deposit located further to the west is in less deformed sediments within the core of a small anticline. There are wide variations in ore type fran lad sulphide chalcopyrite - pyrrhotite - pyrite to high sulphide sphalerite - galena - pyrrhotite - pyrite assemblages. The deposits ccnmonly contain an inner zone of quartz - sulphide - chlorite veining grading outwards into a chlorite halo containing quartz - carbonate veining. The Elura deposit differs in having an inner massive sulphide zone surrounded by a zone of big-Fe carbonate formation. The mineralisation probably formed during regional metamorphism and deformation in the Early Carboniferous. A possible genetic model involves the injection of metal bearing hydrothermal fluids formed in the upper mantle or lower crust up basement structures into the overlying Cobar Supergroup sediments. An alternate model proposes the leaching of metals from the sediments by brines formed during metamorphism and subsequent emplacement in favourable structural zones.

Jan 1, 1983

Evolutionary changes to the original sizer concept are mild when compared to those which have taken place in the engineering standards embodied in today's commercially available machines. This paper examines the principles of sizer operation and reviews the development trends in new applications for this unique screen type.

Jan 1, 1978

By Y Li, B Shen, S Zhang

Jointed rock mass is often encountered in rock engineering and its stability has always been a major concern in underground engineering. To analyze the stress characteristics and their variations in jointed rocks, in this study, a new concept of sub-instability stage before rock failure is defined, and a new experimental method is used to investigate interaction between defects and intact rock of the jointed rock mass during the subinstability stage., Firstly, external characteristics of stress and failure mode of the whole jointed rock are investigated systematically by conducting uniaxial compression tests on red sandstone samples with a set of preexisting open flaws of different sizes, and the interactive damage of intact parts and defects in the subinstability stage was further studied. Secondly, rock-like material samples made of bonded plaster blocks were tested and internal data from stress sensor between the strong and weak segments were collected. The transforming processes from independent activity of the individual segment to overall interactive movement of jointed rock before the unstable failure were analysed. The test results indicated that the subinstability stage marked the beginning of interactive failure between the intact rock and defects. In the early subinstability stage, the relatively intact parts bore most of the load in a jointed rock mass, and the defects were damaged firstly which caused high strain around it. The areas of high strain increase rapidly, extending and migrating, causing damage to the intact parts. In the later sub-instability stage, the interaction effect reached its maximum, and a large number of cracks appeared in the intact rock and they propagated and coalesced. Intact parts experienced rapid failure and then the jointed rock failed. The experimental method used in this paper to identify the sub-instability stage could be used to identify failure precursors of jointed rock masses and to develop technology for disaster prevention in rock engineering. CITATION:Zhang, S, Shen, B and Li, Y, 2018. Experimental studies on interactive failure characteristics of jointed rock, in Proceedings The Fourth Australasian Ground Control in Mining Conference (AusRock), pp 453–461 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 30, 2018

By Flierman GA, Van Toor CH

Investigations were carried out of burden distribution using a full scale model of the furnace top. Various charging sequences were used and large differences were found between ore charged as sinter-pellets and as pellets-sinter. These were attributed to the differences in the angle of repose between the two materials. Permeability index was defined which was independent of the driving rate from which a furnace resistance index was obtained for use in weekly reports. Results are summarised as a single expression between blast rates and pressures and the values of Qbl and Qmax are continuously measured to aid the operators in controlling the wind rate in the safe AP region. Results also indicate a reserve in capacity of No. 7 BF.

Jan 1, 1975

Underground space can be defined as space below natural ground level which can be used as an alternative to an above ground location. While many of our above ground structures inherently involve underground excavation for foundations and services, the term underground space specifically refers to organised development of underground openings and of the underground domain. For example, the services to a city such as power, gas, sewerage, water and communications are installed in a congested array which usually requires roads to be dug up when the services need to be accessed. An underground space installation of services would involve a well planned conduit which is easily accessed without any excavation. The concept of using this virtually untapped land resource to the advantage of our expanding cities is gaining considerable interest in Australia. Overseas, in the Scandinavian countries and some Asian countries, underground space has been used for centuries; in Great Britain, France and the United States of America over the last century and in Japan for over a decade. This paper focusses on the types of underground space usage which should be competitive with above ground use and suggests areas in which the competitive edge may be improved in favour of underground space. In particular, considerable advantage is seen by using well-planned underground space developments in major cities, where the strategic central location of the development takes advantage of proximity to potential users. However, the largest single factor affecting the acceptance of underground space is the high capital cost of construction, even though an underground space development may result in lower operating costs and reduced long-term maintenance costs. While excavation methods and associated costs are very much site-specific, the importance of applying the latest technology in rock breakage, with consideration of ground vibration, excavation rates and ground support, remains a major challenge to the development of underground space.

Jan 1, 1995

The orebodies at Kambalda are complexly faulted, folded and intruded. It is realized that the ore reserve calculations will be wrong and steps are taken to minimise the errors. The calculations are a combination of computer data handling and manual input. Initially Geological Ore Reserves are calculated and then production data and experience are used to produce a Planned Mining Reserve. At all stages maximum professional judgement is incorporated. The basis of the calculation is the polygonal method of area estimation, and production reconciliations together with the style of data available indicate that it is a most suitable technique. It is also a tech- nique that is easily communicated to all levels from operators to management.

Jan 1, 1979

Different mineral structures can act as mineral reservoirs for the immobilisation of toxic compounds. In the paper different mineral structures will be explained and their potential for incorporation of heavy metals and anions will be shown. The following structures will be explained (P÷llmann, 2007):apatites (incorporation of heavy metals, silicate apatites);ettringites (fixation of oxo-anions);layered double hydroxides (fixation of heavy metals, fixation of anions, fixation of organics, sorption materials); andmanganese oxides. Different possibilities of solid solution and incorporation in crystal structures will be explained and advantages of stable minerals be proved using experiences with real toxic wastes. In the process of thermal treatment the formation of primary mineral reservoirs will be shown. The precursor phases (similar to well known cement minerals) react in contact with water to form secondary mineral reservoirs (cement hydration mineral products). The formation condition of primary and secondary mineral reservoirs and their stabilities and incorporation possibilities will be shown. Examples for incorporation of various elements are given. Application for water clarification will be outlined.

Jan 1, 2008

This paper describes the effects of physical variables in dewatering of mineral slurries with air as the filtrate displacing medium. Using a mathematical model with material related constants measured in laboratory dewatering curves are simulated for vacuum and pressure filtration. Four different mineral slurries are studied. Basic dewatering curves with variation in air-pressure are shown with iso-energy lines. Variables such as air pressure, feed concentration, cake thickness and cake formation pressure are discussed.

Jan 1, 1989

By Ishikawa K, Kikuchi T, Tokairin Y

Roadheader, developed from coal cutting machines, is generally classified as a tunnel excavation machine for soft rocks in respect to excavation mechanism, machine structure, weight, engine output and so on. In recent tunnel works, however, there is an increasing demand for changing from blasting to mechanical excavation by roadheaders to avoid environmental problems such as noise and vibration. But there exist various difficulties in excavation of harder rocks by roadheaders. In order to explore the possibilities of roadheader excavation, we performed field and laboratory experiments. In the field experiment, roadheader model S-125 (Mitui Miike Machinery Co.,Ltd.) was tested for various rocks of wide range of hardness, and excavation capacity and wear of picks were measured. In the laboratory test, cutting performance of the picks was tested by our cutter testing machine. This report describes thr: of these experiments and discussions :n possibility of applying boom-type tunnelling machines to hard rock excavation based on these experimental data.

Jan 1, 1987

By Vutukuri VS, Budavari S

During recent years many investigators have suggested large spacing to burden ratios to improve the fragmentation obtained in blasting. In spite of these suggestions, most operators still use a conventional ratio of 1 to 2. From single hole longitudinal charge tests in laboratory, it is shown that burden controls the fragmentation. The burden for obtaining uniform fragmentation is smaller than the burden to obtain maximum breakage. Tests on two or three holes show that a larger spacing to burden ratio can be used for smaller burdens, but it is not possible for the larger burdens chosen to obtain maximum breakage. By using finite element analysis evidence is presented to show the effect of spacing and burden relationship on blasting results.

Jan 1, 1975

By Cameron A

In recent years there have been significant developments in the tech- nology available for blast monitoring, analysis and simulation. Progress in these areas has been achieved through research conducted by explo- sives manufacturers and independent research groups from universities and mining companies. Miners are increasingly keen to exploit this tech- nology to help them design blasts which make optimum use of explo- sives to produce easily excavated muckpiles for the minimum possible cost. The art of blast design in the future will increasingly depend on an adequate understanding of the nature of the rock mass, the perfor- mance of explosives and the characteristics required of the muckpile to suit the chosen excavation machinery. Despite recent advances in blast simulation and the prediction of blasting performance, the best way to determine how a particular explosive will function relative to other explosives is to conduct properly designed and monitored field trials. This paper discusses recent work at Mount Thorley Colliery which demonstrates that field blasting trials can be monitored and analysed to provide quantitative data on the relative performance of bulk explosives. Techniques used in the trials included the sampling and analysis of explo- sives, insitu measurement of VOD, monitoring of near and far field vibra- tions, high speed and still photography and survey measurement of muckpiles. These techniques provided data for the analysis of throw, swell, fragmentation and burden movement together with data on the consistency and robustness of different explosive products. The blasting trials allowed both the shock and heave energy of various explosives to be observed in the field and led to the derivation of design rules for the use of differ- ent explosives at the mine.

Jan 1, 1988

By Shatwell DO, Hayward SB, Leach TM

Following acquisition of the Woodlark Island tenement by Highlands Gold Limited, an exploration programme using extensive diamond drilling has confirmed that the style of gold mineralisation is similar to other SW Pacific Rim carbonate base metal gold systems. The two centres of gold mineralisation at Kulumadau and Boniavat-Busai are inferred to be related. to buried porphyry centres localised on NE trending major horst bounding structures. Individual prospects are localised on NW trending cross structures peripheral to the porphyry centres.Gold mineralisation has been derived from the mixing of hot saline magmatic fluids with cool dilute meteoric waters. While the bulk of mineralisation occurs in dilational tensional gash fractures, bonanza grades resulted from fluid quenching in feeder structures. Pre-mineralisation breccias created plumbing systems for hydrothermal fluids and similar paragenetic sequences are defined for Busai and the Kulumadau areas. These include early, distal porphyry, low sulphidation mineralisation, followed by base metal gold and carbonate deposition.

Jan 1, 1994

Traditionally trucks have dominated haulage in open pit mines. Only recently have conveyors begun to be used in the long haul and high lift duties of surface mines. Steep angle conveyors are proven versatile systems for elevating or lowering materials continuously at steep angles to 90¦. This paper describes the design of a bucket-type steep angle conveyor that was developed as a joint research project between the Western Australian School of Mines and the Maanshan Institute of Mining Research in China. The steep angle conveyor can be used as a viable option for transporting blocky ore from open pit mines. A pilot conveyor was constructed and tested to determine its technical and operational feasibility. Furthermore, a computer model based on Matlab mathematical modelling software was developed to simulate the performance of the pilot conveyor. The model enabled to determine the design parameters of industry-scale conveyors to yield satisfactory performance. These conveyors become very cost-effective for those mines having large mine lives and depths greater than about 500 metres.

Jan 1, 2003

By Brown N. R

This paper attempts to highlight some of the problems encountered in the economic exploitation of the deeper coal seams by opencast mining methods. The major cost elements of three methods of overburden removal are examined in relation to the overall cost of winning coal from deeper-lying coal seams. The three overburden removal methods examined are dragline stripping and two systems combining dragline stripping with shovels and trucks at varying depths of overburden. A dragline is, undoubtedly, the most cost effective system of overburden removal for depths of up to 30 metres but it is suggested that, when dealing with incremental overburden depths in excess of 30 metres, engineers should consider carefully the possibility of using a shovel and truck operation, or other system, to augment the use of a dragline.

Jan 1, 1986