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A new lead refinery with a capacity of 230,000 tons per year commenced operation at Port Pirie in October, 1959. This plant superseded the refinery which had operated from 1933 with the advent of the continuous lead refining process. The incorporation of new equipment following local metallurgical developments, together with the overseas demand for lead of extremely low antimony content createddifficulties in operating the original plant. The new refinery project was undertaken to cover this disability and to gain the full advantage of the new processes.Desilverising and softening are carried out in units identical in size to those used previously. Metallic zinc is recovered from the entire output of desilverised bullion by vacuum distillation. Final refining is carried out by batch treatment with caustic soda yielding lead of purity previously unattainable at Port Pirie.These two processes replace continuous dezincing by oxidation, a high temperature process which caused large quantities of lead and antimony to be recirculated. The final stage is a batch process; therefore the product composition can be checked before casting. Individual batches can be adjusted to produce special alloys to consumer's specification.Improved casting equipment allows the quantity production of pigs of good physical characteristics either as 56 lb bars or 2000 lb pigs.This, together with the high purity of the lead, assures the Broken Hill Associated Smelters Pty. Ltd. (RH.A.S.) position in world markets.Automatic control systems are extensively employed, particularly on the vacuum dezincing unit.The anticipated financial benefits have been achieved mainly by a reduction in the tonnage of recirculated materials, a smaller labour force, and reduced maintenance requirements.INTRODUCTIONIn December 1956 a decision was made to build at Port Pirie a lead refinery on a completely new site, and in October 1959 the new refinery was brought into operation. This plant superseded the lead section of the old refinery which...

Jan 1, 1963

By J Meikle

A projected image is not always a true representation of a situation, or indeed an industry. This is often the case of the mining and minerals industry, which has frequently been portrayed in a negative light with a male dominance stigma attached. However, these issues can be combated for both the industry and its future, current undergraduate students, through undergraduate industry experience. In particular, vacation work enables female students to dispel many myths surrounding the industry and realise that the mining and minerals field offers career development for both genders. This paper will discuss how vacation work enables students to make important career decisions even before they have graduated. Industry experience provides undergraduates with the opportunity to gain practical knowledge relevant to their field of study. Additionally it allows students to observe the nature of the industry and the sacrifices necessary to advance careers. The prior insights into an industry are relevant to all students, but particularly female students, who might otherwise be dissuaded from a career in mining. This paper is written from the perspective of two female undergraduate students studying Mining and Minerals Processing Engineering.

Jan 1, 2006

By Kyle J. H, Misra V. N

The recovery of copper from a flotation concentrate using ferric chloride leaching has been investigated. The concentrate from the Horseshoe Lights Mine near Meekatharra, Western Australia, contained mainly digenite, pyrite and talc minerals. Over 95 per cent of the copper was dissolved in an acidified ferric chloride solution in one hour at 70¦C and ambient pressure. The pyrite and gangue minerals did not react. The leaching process was found to consist of four separate reactions and the shrinking core model was used to describe the process. The effects of particle size, temperature, concentration of FeCls, stirring speed and leaching time on metal dissolution were investigated. The apparent activation energies in the second, third and fourth reactions of leaching of copper concentrate were 28.8, 11.9 and 53.9 kJ/mol, respectively. The optimum conditions for the leaching of copper from the concentrate, within the range of conditions studied were: particle size 63 per cent minus 38 ¦m, a ferric chloride concentration of 1.48 M, a temperature of 70¦C, and a stirring speed of 800 rpm.

Jan 1, 1991

By S Bright, M J. Masamvu, E K. Chiwandika, S Dandi, S M. Masuka

The depletion of high-grade hard and lumpy chrome ores has forced Zimbabwean ferrochrome producers to resort to low-grade friable ores that have an average of 28 per cent fines against a set limit of 12 per cent. Submerged open arc furnaces currently in use are associated with eruptions within the furnace because of the high amounts of fines, high energy consumption, as well as high SO2 and CO2 emissions. Traditionally employed agglomeration methods such as pelletising and the use of coke in the furnace have been discarded because of the pressure to lower operational costs and to achieve higher profit margins. This research aims to develop a method to incorporate lowgrade friable ore fines and unprocessed coal into production while lowering CO2 and SO2 emissions through a closed direct current (DC) arc furnace. The closed DC arc furnace could incorporate the friable ores and coal while maintaining above 90 per cent reduction rates. Preliminary findings also show that energy consumption could be reduced by up to 35 per cent by incorporating a pre-heating and pre-reduction system using the flue gases from the furnace. In the proposed circuit, the cost of production per ton of ferrochrome might be potentially lowered by an average of 30 per cent.

Jun 19, 2024

By R Blin, R Walde, R Belli, D Inaudi

A fiber optic distributed sensing system allows the monitoring of parameters useful to determine the short- and long-term behaviour of the structure in response to the external actions, including, eg seismic activities as well as long-term phenomena such as seepage, tunneling, sinkholes, and other geo-structural movements. Monitoring of large retaining structures with such a system provides direct strain/deformation and temperature measurements on the broad interior area with an arrangement of several sensing cable lines, enabling early detection, localisation and sizing of subsurface damages. Measurements are provided every meter along the entire sensing cable, this is particularly important in such cases where the location of defects and damages cannot be predicted. Fiber optic distributed sensing cables are generally available for retrofit installation inside the dam structure using trenches on the downstream face or laid during construction below the geomembrane liner within the bedding sand layer. Mapping the cable route enables exact correlation between a linear coordinate on the cable length and a position in the dam. Cable installation is envisaged to be carried out during further raising of the embankment; additional cable sections are plugged to the previously installed cables and measured with the existing measurement system, requiring only an update of the mapping. The measurement system is placed remotely from the sensing area since a section of sensing cable can be used to link to the sensing area at the storage facility several kilometers away. The system is available for on-line, 24/7 real-time operational data management. Such fiber optic distributed sensing systems allow storage facilities to be monitored with long, accurate, continuous and precise data for geotechnical diagnostic purposes. This contribution will introduce the principles, benefits, and limitations of this technology.

Jul 1, 2021

By M Wieloch, D Wimpenny, M Chappell

Fibre-reinforced geopolymer concrete (FRGC) contains no Portland cement or steel reinforcement, but instead uses synthetic fibre reinforcement and a geopolymer binder. The use of geopolymer binder in lieu of Portland cement reduces the concrete’s embedded energy (CO2 emissions) whilst the use of synthetic fibres eliminates the issue of reinforcement corrosion, thus enhancing the overall long-term durability of concrete. This paper presents the development of FRGC during a three-year project funded by the Victorian Science Agenda and a consortium of five organisations. The work involved laboratory and field trials and the production of prototype tunnel segments that have been subject to durability and fire testing.FRGC has exceeded the performance of the Portland cement-based control mix in terms of flexural strength, chloride diffusion, water sorptivity and drying shrinkage. Furthermore, the FRGC segments subjected to a simulated hydrocarbon fire test did not exhibit explosive spalling; however, the creep of FRGC was approximately three times that of the steel fibre-reinforced Portland cement-based control mix. The compressive strength and tensile splitting strength of the FRGC were also lower than the control mix. These differences need to be allowed for in the design using FRGC.Prototype bolted tunnel segments of up to 0.8?t mass have been produced from FRGC using standard production techniques and ambient curing. These were successfully produced within a 24-hour production cycle. Cut sections through the segments showed good compaction and even distribution of fibres. The estimated carbon footprint of tunnel segments produced using FRGC is approximately 70 per cent less than that of Portland cement-based segments containing 25 per cent fly ash and steel reinforcement.The results to date indicate that FRGC has the potential to produce a new generation of tunnel segments and, in general, precast concrete products with increased durability and substantially reduced carbon emissions compared to the Portland cement-based concrete with steel reinforcement.A summary of further research carried out by CH2M HILL into a complete elimination of ferrous inserts from segmental concrete tunnel lining is also summarised in this paper. The use of non-ferrous connectors for radial joints in combination with the FRGC technology in the manufacture of tunnel segments will effectively lead to development of a new generation of segmental tunnel lining systems.CITATION:Wimpenny, D, Chappell, M and Wieloch, M, 2014. Fibre-reinforced geopolymer concrete – an innovative material for tunnel segments, in Proceedings 15th Australasian Tunnelling Conference 2014, pp 345–352 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By D J. Williams, G W. Wilson, S, A B. Tran

A comprehensive field program was implemented to evaluate the internal structure and hydrology of two full-scale waste rock piles. The excavation of waste rock dumps for in-pit disposal at the two mine sites provided an opportunity to characterise the in situ properties of the dumps given contrasting geologic and climatic settings. The internal structure and materials within the dumps were observed and sampled as the waste rock piles were being excavated and placed in the open pits for permanent closure. The field program was designed to fully characterise the structure and material properties of the waste rock. The alteration of the material by physical and chemical weathering was also observed. Samples were analysed for paste pH, water content, grain size distribution and geochemistry. In situ density and matric suction were also measured. Soil water characteristic curves and saturated hydraulic conductivity were measured for representative materials. These properties were used to predict seepage pathways through the waste rock and the resulting outflow geochemistry using the finite element model SEEP/W. The materials in the dump at Site 1 were predominantly fine-grained in texture and highly weathered. The presence of dipping beds with alternating coarse and fine materials was evident throughout the profile of the dump. The structure of the waste rock appears to have an impact on the hydrologic pathways within the waste rock pile. The material in the dump at Site 2 was found to be competent and resistant to particle size breakdown. The particles range in size from clay size to large boulders with the median particle size being approximately 125 mm in diameter. The coarse-grained texture of the waste rock resulted in a loosely packed arrangement of coarse particles with little matrix material infilling the pore spaces between the coarse-grained particles. Seepage modelling for Site 1 was completed to predict seepage paths based on observed structure and hydraulic properties measured in the laboratory. The modelling showed that materials with a fine grain size distribution become the dominant pathways for flow through the waste rock pile. The modelling also showed that layers with high silt and sand contents are subject to the highest flow rates. Finer grained clay rich layers have a low hydraulic conductivity and do not convey large volumes of water. Alternately, coarse gravel and cobble materials are unsaturated under values of matric suction that approach the residual water content of the material and do not transmit liquid water. The seepage modelling together with the results of the geochemical analysis show that the dominant particle size that receives the most fluid flow and flushing ranges from fine sand to silt, corresponding to materials with air entry values ranging between 5 kPa to 50 kPa.

Jan 1, 2003

By M Zaluski, D Bless

An innovative, biological treatment process has been designed by MSE Technology Applications, Inc to treat and control acid mine drainage (AMD). A field-scale demonstration is being conducted under the Mine Waste Technology Program using water flowing from a historic mine in Montana. A successful demonstration of an in situ process will allow it to be employed at numerous other abandoned or remote mines, which discharge AMD, an acidic, metal-contaminated water. Conventional treatment methods are costly and are often impossible to use at remote locations. MSEÆs technology uses a biological system to clean up AMD. The In situ Passive Biological Treatment Process utilises nonpathogenic bacteria, which are able to neutralise acidic mine water and remove contained toxic metals. These bacteria live within a series of pile-type reactors inside the mine. The bacteria are fed inexpensive waste products. The resulting discharge is clean water flowing from the mine. This presentation will show that this technology offers a natural cleanup method for the nationÆs numerous abandoned mines. Work on this project was conducted under Interagency Agreement No DW899388-70-01-1 between the US Environmental Protection Agency and the US Department of Energy (DOE), and was performed at the Western Environmental Technology Office through the DOE National Environmental Technology Laboratory (DOE Contract No. DE-AC22-96EW96405).

Jan 1, 2003

By Y A. Stepanyants, J Crawford

A practical field method for determining the maximum value of the intrinsic oxidation rate, Smax , of sulfidic materials in waste rock dumps is proposed. Knowledge of the intrinsic oxidation rate of sulfidic materials distributed in a dump is necessary for predictive modelling of oxidation and pollutant generation over time. The suggested method uses the fact that drilling waste rock dumps to install probes for monitoring temperature and oxygen concentration causes large volumes of air to be injected into a dump by the drill rig. By measuring the rate of decrease of oxygen concentration along the length of a borehole immediately after installation, it is proposed that Smax can be calculated at different depths. The aims of this work were: to derive a simple, practical formula for the estimation of Smax from the oxygen concentrations measured over time, based on some simplifying assumptions; to use a two-dimensional numerical model that incorporates all the necessary physical processes to model the behaviour of an aerated dump over time for a reasonable range of dump and material parameters; and to compare the results of the two approaches to assess the validity of the simple formula as a method for estimating Smax. It has been found that the technique can provide reliable estimates of Smax when the value is of the order of 10-7 kg(O2) m-3 s-1 or greater. At the lower end of the range however the radius of the zone aerated during drilling becomes an important parameter and further work has been recommended to investigate this aspect of the method.

Jan 1, 2003

By McNay L. M

Two field studies to monitor fill pres sures and vein-wall deformation were conducted in mines of the Coeur d'Alene mining district in Idaho. Both operations employed cut-and-fill mining techniques in nearly vertical veins aver- aging 10 feet in width, and backfilled with classified mill tailings. Hydraulic pressure cells were used to measure transverse, longitudinal, and vertical pressures within the backfilled stopes. Rock bolts extending into the manways and mechanical closure devices were used to monitor vein-wall convergence. Continuous recorders were used with selected pressure cells to prolong the life of the installation. Transverse pressures in excess of 600 psi and stope wall closure up to 22 inches were re- corded. Closure rates were higher at midheight of the stope than they were near either sill, indicating that the vein walls react similarly to a beam supported on each end.

Jan 1, 1973

By Diehl GW, Kuntonen J

The Tamrock all-hydraulic rock drilling system 400 has been developed to cover as wide a drilling range as possible, from 35 mm holes in tunnelling, roofbolting and development work to 64mm holes in long hole production drilling. Field experience during the last five years shows that the Tamrock drill covers this range in a way that no other rock drill on the market does and recently the range has been success- fully further expanded to cover bench drilling with 76 mm holes.

Jan 1, 1978

By R Van Laeren, G Langerak, S Fityus, K Koosmen

Co-disposal of partly-dewatered mixed-plant rejects (MPR) from coal processing into spoil dumps is gaining favour amongst Australian coalmine operators in preference to conventional tailings disposal methods which require a tailings dam. Owing to their often low permeabilities and high degrees of saturation, MPR materials may be prone to the development of excess pore pressures when covered by spoil during routine dump advancement. The likelihood of dump failure will increase if these pore pressure regimes and the associated delay of shear strength development are not accounted for during waste dump design. To date however, little is known about these pore pressure regimes due to the complexities associated with their in situ measurement.This paper describes the in situ measurement of pore pressures in a cell of MPR placed within a coalmine spoil dump. Four vibrating wire piezometers (VWPs) were placed within a cell that was then filled with MPR and allowed to consolidate under self-weight before advancing an adjacent tiphead across the cell. The VWPs recorded the transient pore pressures during MPR placement and dump construction, and their interpretations are described within the context of laboratory measured parameters. Following analysis of the measured pore pressures, their implications on shear strength and dump design are also discussed.CITATION:Koosmen, K, Langerak, G, Simmons, J, Fityus, S and Van Laeren, R, 2015. Field measurement of transient pore pressures within co-disposed processing rejects placed in a spoil dump, in Proceedings Tailings and Mine Waste Management for the 21st Century, pp 63–72 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By M Armony, J F. C L Costa, J C. Koppe

Linear kriging methods fail to estimate local grades and local reserves for highly skewed variables due to three reasons: it uses only part of the available data information, it has no physical principles associated with the mathematical proceedings to minimise the problems, and it works with continuous variables while data are discrete because of the limited precision of any equipment. The techniques commonly used up to now to solve the highly skewed variables estimation problems were unsuccessful, unless mathematical rigor is abandoned. Even the method of multiple indicator kriging is not satisfactory. This paper presents a new framework, the field parametric geostatistics (FPG) that transforms noisy variograms into well-behaved variograms and justifies mathematically empirical procedures commonly used, as trimming or capping arbitrarily very high values. The method, when applied to non-skewed variables, yields similar results to classic kriging. The methodology is illustrated in a case study at a gold deposit in Brazil, and compared to results obtained by usual techniques.

Sep 26, 2011

By A Xenidis, N Papassiopi, I Paspaliari

Acid generating sulfidic tailings covering a surface area of approximately ten hectares have been deposited in the historic mining area of Lavrion in Greece. For the development of a remediation strategy, the performance of three alternative acid generation control techniques was assessed under actual field conditions. The techniques involved the application of dry covers, including a synthetic HDPE liner and a compacted clay layer with capillary barriers. Furthermore, the potential formation of a low permeability hardpan layer at the sulfidic tailings surface by limestone addition was investigated. The field tests covered an area of 2500 m2, which was divided in equal quadrants, corresponding to the control plot and the three alternative remedial options. To monitor the amount and quality of percolated water, lysimeters were installed beneath the four plot areas. Based on the monitoring results over a period of six years, due to the dry climate encountered in the Lavrion area, a low amount of water percolates through the pyrites if no action is taken (control area), corresponding to 20 - 25 mm per year. This water is highly acidic, pH = 1.2, and contains a heavy load of contaminants, eg Fe 40 g/L, Zn 15 g/L, and As 1.5 g/L. The HDPE cover eliminated the percolation of water into the material for a period of five years, whereas thereafter the volume of leachates increased to values similar to those recorded in the control plot. The water collected in the lysimeter of the clay cover has been minimal corresponding to approximately five per cent of the drainage volume produced in the control area. In the fourth plot, which involved limestone addition to sulfidic tailings, the volume of drainage initially collected was almost double compared to the control area. After three years of monitoring, significant reduction in the amount of percolated water was observed, attributed to the formation of a cemented layer (hardpan), at a depth of 40-80 cm from the testpad surface.

Jan 1, 2003

By E Villaescusa, C Drover

Fully resin encapsulated threaded bar and cement grouted cable bolts are common forms of reinforcement for underground mining excavations constructed at great depth. These elements are frequently installed to dissipate the dynamic loads caused by violent rock mass failure mechanisms. Failure of the ground support scheme without rupture of the reinforcement elements implies that the maximum energy dissipation capacity of the scheme was not utilised. The ground support damage mechanisms are useful to identify in this context as they reveal vulnerabilities which limit the scheme performance. This paper presents a number of field observations of reinforcement performance following a range of dynamic loading conditions. It was observed that fully resin encapsulated threaded bars exhibit variable behaviour. In particular, inconsistent resin encapsulation was frequently observed in combination with surface support failure, indicating that the retention function of these elements may allow preferential loading of the surface support system. Observations of cement grouted, twin-strand plain cable bolts reveal a common mode of damage involving differential displacement across the steel-grout interface and slip of the cable within the borehole. This is common where strands are not mutually tensioned with barrel and wedge assemblies. Surface fixtures that exceed the strength capacity of the cable strand are required in order to minimise the occurrence of this response. Improved load transfer from the rock mass and surface support to the cable can thus be achieved, particularly where small block size failure occurs.CITATION:Drover, C and Villaescusa, E, 2016. Field performance of fully encapsulated reinforcement during violent failure events, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 659–668 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By M Wen, J Gerit, C A. Pelletier, D Muggli

On-land waste rock dumps at BHP Billiton Base MetalsÆ Island Copper Mine (ICM) near the northern end of Vancouver Island, B.C. continue to discharge ARD. These waters, which amount to approximately five million cubic metres each year, are injected into a three-layer, meromictic pit lake for treatment. The top layer is brackish water, replenished by each yearÆs rainfall (amounting to nearly 2 m/year). This top layer of water must meet effluent permit limits for heavy metals. This water eventually exfiltrates through a æbeachÆ waste rock dump, which is 93 per cent submerged along the north shore of Rupert Inlet. The middle and bottom layers of the Pit Lake are saline and currently oxic (2 mg/L dissolved oxygen) and anoxic (0.03 mg/L dissolved oxygen), respectively. Spreading of a liquid fertilizer every ten days throughout the top layer results in plankton and bacterial blooms that scavenge zinc, copper and cadmium out of this layer eventually to become mineral sediment in the bottom of the pit lake. Adsorption on planktonic skeletons and mineral precipitates also scavenges these dissolved metals from the middle and bottom layers to form bottom sediment. Sulfate reduction has recently begun in the bottom sediments. Diagenetic processes in the bottom sediments will eventually transform most of the dissolved heavy metals into insoluble sulfides. Cycling of ferric iron between the sediment and the water column and back seems to contribute dramatically to the biogeochemical metal removal processes. This biogeochemical system serves to maintain the top-layer water well within permit limits for discharge to the environment.

Jan 1, 2003

By Ellis WK, Greenwood-Smith R

A nuclear technique for the analysis of copper in bulk materials has been developed and successfully field tested at Mount Isa Mines Limited. The technique utilises the gamma-ray resonance scattering process. A bulk analyser based on this technique gives a rapid and accurate measurement of the percentage by weight of copper or nickel aver- aged over a large mass of sample, typically 20 kg. The only sample preparation required for accurate analysis is crushing to -2.5 cm. At Mount Isa over 100 mineral samples covering a wide range of rock types and copper contents were analysed. Bulk analyser assays and chemical laboratory assays agreed closely for underground pillar-extraction and geolog- ical chip samples, conveyor belt samples, and finely ground samples from the ore concentrator. For the concentrator samples, the root mean square deviation between bulk analyser and chem- ical laboratory assays was 0.06 wt.% copper. The chemical assay errors for these samples were about 0.06 wt.%

Jan 1, 1975

By Garnsey R. G T, Wenk G. J, Toop A, Sowerby B. D

A bulk mineral analyser (BMA) suitable for the determination of Cu or Ni in bulk ore samples has been developed at the Lucas Heights Research Laboratories. This analyser, which uses the nuclear resonance scattering technique, is highly specific to the wanted element. The technique has previously been extensively field tested for copper at Mount Isa, Queensland.The present paper discusses the field trial in 1982 of a commercial prototype BMA for nickel. The trial was undertaken at the lateritic nickel mine at Greenvale, Queensland. The BMA and its shielding, together with a laboratory spectrum analyser, were sited in the sample shed adjacent to the workings. Two hundred and thirty-eight ore samples taken directly from the mine blastholes were assayed by the BMA. The average mass of sample was 12 kg, metal contents varied from 0.2 to 3.5 wt/per cent Ni and 4 to 43 wt/per cent Fe and free moisture varied from 11 to 55 wt/per cent. A measurement took 10 min to complete, although this time could have been reduced at the higher nickel grades. The r.m.s. deviation between BMA and chemical assays was 0.09 wt/per cent nickel. Iron and bulk density were also determined by the BMA, r.m.s. deviations being 1.7 wt/per cent and 0.03 g/cmJ respectively. Similar results could be expected from a BMA in routine industrial use at other nickel mines.

Jan 1, 1983

By Y Wei, P Soole

This paper gives a brief description of VirtuoBlast technology ù a new, automated and highly interactive stereo vision technology which has been developed in CSIRO Exploration and Mining. VirtuoBlast technology is an integration of three advanced technologies - close-range digital terrestrial photogrammetry, oblique stereo imaging or high-speed stereo imaging, and temporal-spatial image matching technique. VirtuoBlast has been developed for the automated 3D measurement of blasting through rapid collection, processing, analysis and visualisation of 3D data related to blasting. A major field trial has been undertaken in August 1998 at the KCGM super pit. The field trial involved three applications of the technology, namely, pre-blast 3D surface mapping; post-blast 3D performance measurement; and temporal-spatial modelling of dynamic blasting process. This paper presents some results from this trial with emphasis on the application of VirtuoBlast technology to pre-blast 3D surface mapping and post-blast 3D performance measurement. Application to the temporal-spatial 3D modelling of dynamic blasting process will be presented in a separate paper. Pre- and post-blast surface models derived using both VirtuoBlast technology and conventional field survey method are presented. The differences in results using the two mapping methods clearly show that the digital photogrammetric technique has many advantages over conventional survey methods. Results of pre- and post-blast from the field trial have demonstrated the potential of VirtuoBlast technology to efficiently perform pre-blast 3D surface mapping and post-blast 3D performance measurement of production blasts. Demonstrated applications of VirtuoBlast technology to automated 3D measurement of blasting are showing an exciting future in advancing blasting science and modern blast design. The basic technologies are in place, however, continued improvements to the functionality, robustness and outputs are needed. The challenge is to build on the current state-of-the-art, by developing techniques and hardware which can be easily transferred to and implemented by the mining community. Current and future research and development will see improvements in imaging systems, automatic image processing and 3D data analysis.

Jan 1, 1999

The Mobile Miner MM130 was delivered to Broken Hill in February 1992. During March the machine was extensively trialled on the surface to test manoeuvrability, climbing ability and muck handling prior to being trammed underground in April. The first cutting test on 30 April 1992 provided promising results. The machine has undergone continual development since it arrived in Broken Hill with aims of ensuring reliability and achieving performance goals. The paper gives a detailed account of recent performance comparing this with the predicted Performance.

Jan 1, 1993