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By D Macfarlane, T McMorran

  This paper describes the design and construction of the upper section of the Pike River Mine Access Road. The road extends 11 km from Logburn Road alongside Big River on the West Coast of the South Island of New Zealand up Pike Stream to the new mine portal on White Knight Stream (Figure 1). This new road starts on alluvial terraces, then partially follows an old logging road before entering virgin bush and traversing the true left bank of a steep sided gorge on Pike Stream some 50 - 100 m above the stream before dropping down to the mine entrance. Its development has been an extended process from route selection, consenting through to design and construction.   The paper focuses on the 1 km section of road between the Amenities Area (Figure 1) and the portal. This section of road is a steep section through the gorge, principally on Conservation estate, and has presented the most challenges and required the greatest effort to obtain the regulatory approvals, prepare the design and to construct. This paper outlines the history of the challenges faced and how the road was successfully developed.

Jan 1, 2007

By Walton M. C

A combination of flotation and smelting technologies is proposed as a cost-effective means to maximise the revenue of base metal operations. The proposed treatment route breaks the grade - recovery nexus associated with the treatment of ores exhibiting difficult mineralogy in conventional plants. Aspects of the two technologies are reviewed and typical capital and operating costs presented. A significant improvement in revenue is demonstrated in a worked example, where a copper-lead-zinc operation is examined in terms of the conventional and proposed treatment options. For the selected ore, the net smelter return per tonne of mill feed improved 57 per cent, from US$89.70 to US$141.10 with the proposed treatment option. This represents an additional US$51.4 million in annual revenue. Metallurgical operating costs increased by US$20.12 per tonne of mill feed for an incremental capital requirement of US$30.3 million for an existing operation.

Jan 1, 1992

Our ultimate resources come from the Sun and the Earth System. At this time we face a world crisis in energy, water and soil resources. Global pollution problems are increasing in almost all nations. There is an urgent need to use our vast knowledge with a new wisdom and this requires new integrated teams of experts to provide the best alternatives for the needed new development problems. These teams must include economists, engineers and a broad spectrum of scientists. Today it is possible to produce clean energy, stop soil erosion, clean water and reduce and use wastes of many types.

Jan 1, 1995

The Devonian Mount Morgan gold-copper deposit was situated on the western margin of the Calliope Volcanic Are assemblage, in the northern New England Orogen. Recorded production from commencement of mining in 1882 to mine closure in 1989 stand

Jan 1, 1994

By Murray C. G

A database of over 1300 earthquakes has been used to investigate the relationship between seismicity and tectonics in two areas of eastern Queensland and NE New South Wales. These areas have been monitored by several networks that were installed primarily to monitor seismicity associated with the impounding of large reservoirs. Events that occurred prior to the installation of these networks have been excluded from the analysis because they have large uncertainties in location.Seismicity in SE Queensland and NE New South Wales is concentrated in the coastal regions. Activity also extends off the coast of Queensland and beyond the continental shelf. The coastal activity is mainly within the New England Fold Belt. An area of the fold belt overlain by the Clarence-Moreton Basin is also active. There is an area of activity near St. George that correlates to the Wunger Ridge. Fraser Island and the adjacent onshore area, near Maryborough, are notably aseismic.Within the New England Fold Belt there is a NNW trending zone of concentrated activity that includes the South D'Aguilar Block and the Esk Trough as far as Gayndah. The Nambour Basin, the Gympie Province, and the southern portion of the Yarrol Block are significantly less active.Composite focal mechanisms of several groups of accurately located earthquakes in SE Queensland indicate predominantly reverse faulting. This faulting is the result of the crust being compressed horizontally in a NE-SW direction.Activity in the Burdekin Falls Dam area of central eastern Queensland is confined to the Drummond and Bowen Basins. There is also significant activity offshore from Townsville and Bowen.

Jan 1, 1990

By Jorgensen FRA, Moyle FJ, Turner TM

Laminar flow furnace techniques and thermal analysis were used to study the combustion of Kambalda nickel concentrate and Collie coal. The study was made to ascertain the suitability of the latter as a replacement for the fuel oil currently burnt in a flash furnace at the Kal- goorlie Nickel Smelter. The coal was found to ignite at temperatures between 500-600¦C which was the same as that required for the most reac- tive component of the concentrate, namely py- rite. The rates of reaction of both the coal and concentrate were dependent on oxygen con- centration. Sulfur dioxide hindered the combus- tion of concentrate and of coal, the effect on the concentrate being the more pronounced. The effects of moisture content and the tendency for spontaneous combustion of the coal were also noted.

Jan 1, 1982

By Mathew P. J

The CSIRO Division of Mineral and Process Engineering in Melbourne has been developing on-stream analysis sensors based on neutron and gamma radiation for better control of quality and process operations. This has resulted in the development of Ironscan, an on-stream analyser that measures the iron content of both lump and fine iron ore on conveyor belts. It can be mounted under existing conveyors with minimal modifications to the conveyor structure and can cope with steel cables in the belt. An interface gauge and an on-stream coal ash analyser have also been developed, both based on measurement of natural radioactivity. The interface gauge monitors the interface between liquor and mud in thickeners and washers, provided the natural radioactivity of the mud is sufficiently high to detect it above background. The natural-gamma ash gauge is a valuable addition to the Coalscan range of ash gauges. It is applicable to heavily laden coal conveyors or bins where the coal bed thickness exceeds 30 cm, and also to lightly laden conveyors, provided the coal is profiled on the conveyor.

Jan 1, 1991

By Hammond J. R, Ward T. A

The Tom Price orebody, in the Hamersley Ranges of North West of Western Australia, is mined by Hamersley Iron Pty. Limited. The orebody is a folded sequence of hematite and shale bands capped with goethite, with a con- sequential variable iron content. The overall grade is below that required to yield spec- ification product, necessitating selective mining, 'Zone Plans' based on geological structure have been developed to yield forward information on material types and grades. Short and medium term mine plans - the initial stage of quality control - are based upon these 'zone plans'. Blasts are laid out to break to the grade boundaries, thus minimising dilution, and the samples taken from the blasthole cuttings provide blast grades. Blending of shovel out- put from different blasts forms the operational basis of grade control. Shales, being more friable than hematite, produce fines that are lower in iron grade than lump. Quality control in the mine centres around maintaining the target fines grade, compensation being applied in the mine if the fines grade lies outside the target range.

Jan 1, 1973

By Lloyd F, Bayley F. J

The new South Mine in the Western Deep Levels complex is destined to become an ultra deep project extending to depths of 4 200 m below surface and where rock temperatures are likely to exceed 65 ¦C. Initial estimates put refrigeration requirements at 133 000 kWR. A surface refrigeration plant with an initial capacity of 42 000 kWR has been commissioned and will be used for mining the upper levels.

Jan 1, 1988

By A Jurg, F Leclercq

The total drill and blast concept is widely known in the mining industry. On the contrary, the quarry industry rarely adopts such working methods. Based on the experience of the CBS quarry in the North of France, this paper shows how up-to-date blasting technology and simple control methods can significantly improve the overall Mine to Mill efficiency of a quarry. The CBS quarry, in partnership with the EPC group and Nitro- Bickford Company, adopted a new working process three years ago aimed at increasing blast performance and related productivity of the downstream process (loading, hauling and crushing). The pattern geometry of each blast is controlled and explosive charging is carried out following the æconstant specific energyÆ CSE concept. This method provides a homogeneous fragmentation distribution and reduces vibration peak-particle-velocities. The impact on downstream productivity is controlled by means of a simple information management system, which collects and measures key parameters of the production process such as; hauling cycles, crusher throughput, secondary breaking and vibration peak particle velocity. This information system has clearly proved over time that consistent blast quality could be achieved, leading to a 30 per cent improvement in quarry productivity. Improved energy control of blasting through optimisation with electronic detonators, allowed a significant reduction in vibration impact on the environment. Improvement in blasting security, reduction in the environmental impact and productivity enhancement are major benefits that quarries can obtain from these CSE optimisation blasting methods.

Jan 1, 2007

By Sandvik

Fine grinding in an air-swept ball mill working in closed circuit with a forced vortex air classifier has been investigated first in continuous laboratory and then in industrial scale. Results from the laboratory circuit have shown significant influence of mill load (powder filling) on the capacity of the circuit. In laboratory scale the mill load was measured and controlled by a weighing platform placed under the complete mill set-up. The mill load of the industrial air-swept ball mill has till now been controlled by measuring the power consumption of the mill motor. Thus, it was necessary to operate far from the range of optimal mill filling. To improve the circuit performance, alternative ways of mill load measurement were investigated. An important factor was investment cost, as many fine grinding mills operate in relatively small circuits that do not wan-ant large investment. In this case the task was accomplished by using a piezoelectric strain transducer, which detected strain changes in the mill shell. It was installed in the midpoint of the shell, where the highest deformation was obtained. As the transducer was on the top position, it indicated compression, and on the bottom position it measured tension. By taking the difference between the readings, it was possible to calculate total strain variations, directly proportional to the mill load. The signal from the transducer was sent to a control room via a cordless infrared communication system, employing a microprocessor control card, which could further regulate other operating parameters of the circuit according to the software model. The installation required very low investment cost and provided simplicity of application as well as stability and reliability of characteristics under severe industrial condition. The measurement system made it possible to optimise the mill load and thus increase the production from 3.2 to 3.7 dh (15 per cent), and stabilise the circuit operation.

Jan 1, 1995

By Wilson R. G

Mining conditions imposed by a coal seam roof can be analysed according to natural causes, before consideration of strata control. All types of roof behaviour can be explained by considering only three independent variables. They are roof rock types, rock stresses and discontinuities. Roof rock types encountered in the Sc.ithern Coalfield of New South Wales (NSW) are sandstone, shale, mudstone, laminite and coal. Each rock has its own mode of failure. Lithological stability of the sediments varies from one type to another. Regional stresses upon a coal seam roof will vary in magnitude according to the proportion of gravitational stress, which is related to depth of cover, and residual stress, which is related to the maximum depth of burial and may be gauged by coal rank. Local stresses will vary according to tectonic deformation, related to irregularities in seam structure.

Jan 1, 1976

By Myers I. A, Peters S. G, Bultitude R. J, Dowling K

Gold-quartz and antimony-gold-quartz veins in the Hodgkinson Province are hosted by subgreenschist to greenschist facies metasediments and show no spatial association with granitic rocks. They commonly parallel axial plane foliations or occur in brittle to brittle-ductile shear zones. Detailed mapping in the Hodgkinson goldfield indicates that vein systems are isolated in distinct structural and lithologic domains by post-mineralization faulting. Gold-quartz and antimony-gold-quartz veins have distinctive mesoscopic textures characteristic of the mesothermal vein environment. Some of the antimony-gold-quartz veins are located on domain boundaries which truncate the gold mineralization. In. some areas, tin and tungsten-tin mineralization which are spatially related to Late Palaeozoic granitoids appear to postdate the gold-quartz and antimony-gold-quartz mineralization.Oxygen and hydrogen isotopic studies of vein and alteration assemblages associated with these diverse ores provide constraints on fluid sources and have implications for the origin of mesothermal gold mineralization. The available isotopic data are consistent with a dominantly magmatic source for tin and tungsten-tin mineralization although there is evidence of a late-stage meteoric component in some tin-mineralizing systems. Although a distal magmatic contribution cannot be entirely discounted, the gold-quartz and antimony-gold-quartz veins were probably deposited from deeply

Jan 1, 1990

By Hunt MS

A major diamond mining operation in South Africa is faced with the unique problem of recovering usable water from the fine tailings stream. The kimberlite ore hoisted is washed prior to crushing in order to remove adhered fine clay particles. These particles form a colloidally stable suspension from which it has not been possible to recover clear recycle water. Research has been conducted on this problem for more than 20 years and it is only recently that a breakthrough has been achieved. This paper describes the work done to gain an understanding of the suspension stability and which subsequently led to the testing of a process at pilot-plant Scale.

Jan 1, 1988

Environmental considerations were key factors in the design of the Ranger Uranium Mines treatment plant. The mine is located adjacent to the Kakadu National Park and has an average rainfall of 1.6m per annum. Initially, no contaminated water or liquid effluents are to be released from the project area and thus water management is a key design and operating fact. Particulate and gas emission criteria influenced design as did occupational hygiene factors (dust, radon, housekeeping, maintenance access). Equipment selection and engineering standards were conservative and resulted in the plant attaining design performance in less than three months from the date of commissioning. A number of mechanical and operational problems were experienced and are discussed in the paper, however none of these problems have had a significant effect on production.

Jan 1, 1984

By Lyman GJ

Systems for the routine on-line determination of ash content of process streams in coal preparation plants and handling systems have been in use in Australia for over four years. More recently, monitors for on-line moisture measurement have been developed to complement the ash measurement function. The technology for these systems is reviewed briefly. The development of reliable ash and moisture monitors has made the implementation of automatic systems of coal quality control practical. The emerging philosophies of automatic control in Australian preparation plants are examined with particular emphasis on systems involving dense medium circuit regulation. Related developments in flotation control and coal sorting are noted to complete this overview.

Jan 1, 1987

By Torabi S. R, Daly C. R

Wind blast is the sudden movement of air displaced by the massive collapse of roof rock in underground openings and is experienced as a high velocity flow of air through adjacent workings. The initial flow in the outbye direction is often followed by 'suck back', that is a reverse flow of air towards the newly created void. As part of the Wind Blast Project, undertaken by The University of New South Wales, Department of Mining Engineering, a physical model was constructed. One of the functions of the laboratory wind blast model is to provide insight into the dynamics of the interaction between the falling strata and the air being compressed below. During a collapse, some air is expelled into the surrounding roadways while the remainder penetrates towards the top of the roof elements. In this paper two aspects of the rock mass properties which influence the phenomenon are considered: - Flow paths through the falling roof element, ie the permeability of the roof element; - Bed separation prior to the fall which introduces a void above the roof element. A series of tests was carried out utilising the physical model in order to investigate the relationships between the flow of air through the simulated roadways, the variations in gauge pressure above and below the falling roof element, and the acceleration and terminal velocity of the latter, all as a function of the flow paths through the roof element and of the extent of the void above. The results of comprehensive tests using the wind blast physical model suggested that the time history of outbye air flow in the simulated roadway comprises two distinct phases. a) A primary phase, characterised by a high velocity flow of air which exhibits a peak and corresponds to the period during which the roof element is accelerating. The peak air velocity is related to the acceleration of the roof element. b) A secondary phase, characterised by a residual air flow of a lesser velocity than in the primary phase and corresponding to the period during which the roof element is falling at its terminal velocity. The velocity of the residual air flow is directly proportional to the terminal velocity of the roof element. In a monolithic collapse of a roof element it was shown that the presence of flow paths in the roof element increased the air velocity in the roadway in both the primary and the secondary phases. The presence of an air-filled void above the roof element, on the other hand, influenced the air velocity only in the primary phase by increasing the peak air velocity. The overall duration of the process was however decreased as a result. 'plug type' collapses, where roof failure extends to the ground surface, potentially generate the highest peak air velocities likely to be encountered during wind blasts.

Jan 1, 1995

The overall systems approach to blast furnace aerodynamics is explored including the time and spatial inter-relationships that exist between the furnace lines, tuyeres, burden characteristics, distributor capabilities and furnace operating practice. Attention is called to the time dependent, three dimensional aspects of blast furnace aerodynamics and to the existence of several zones within a furnace where the flow characteristics are different. Changes in furnace operating practice to take further advantage of fully beneficiated burdens including formed coke are discussed from a practical viewpoint. Lessons learned in a variety of shaft furnaces used for other purposes are discussed insofar as they have a bearing on aerodynamics in an iron blast furnace. Questions are raised about the penetration of hot blast in large furnaces. Operating practices and.proposed solutions are evaluated where tuyeres over iron and slag notches are restricted or plugged. Opportunities are presented for using on-line hierarchical computer systems with adaptive tuning algorithms to provide non-linear control of changing process conditions in real time. This will make it possible for the blast furnace operator to optimise a variety of interrelated paramaters, each with different response times. Potential increases in productivity, fuel savings and improved quality control are believed to be within reach.

Jan 1, 1975

By Gole MJ

The Goodyear nickel prospect is located 45 km southeast of Kalgoorlie (31.04¦S, 121.80¦E) near the eastern boundary of Hampton Area - East Location 45 (Figure 1). Nickel mineralisation was discovered on the Goodyear prospect in March 1996 when a reverse circulation drillhole (GYC5), initially drilled in December 1995, was deepened to meet a minimum footwall penetration requirement of 20 in that had been set for the drill program. Approximately 3 in of sulphides averaging 4.9 per cent nickel was intersected from 296 metres down-hole, this being within 2 in of the first end-of-hole. Hole GYC5 was part of an eight hole drilling program undertaken by Titan Resources in late-1995. This program was designed to test whether nickel mineralisation in the Dunlop prospect, discovered by the Western Mining Corporation - BHP Camylia Joint Venture immediately east of the East Location 45 boundary, continued across the tenement boundary. The area targeted by the initial drill program had been explored by Western Mining Corporation in the mid-1980s using extensive surface sampling and a drilling program that included 17 RAB and percussion drillholes. None of these holes intersected nickel Mineralisation.\

Jan 1, 1996

The major copper orebody at Mount Isa is being extracted at a rate of four million tonnes per year. The method used requires an equivalent rate of back filling with (mainly) cemented fill. There were three major incentives for developing this mining system. The first was the prospect of high ultimate recovery of the orebody. The target is 100% recovery. Also the proposed stoping layout appeared to offer significant advantages in development and production costs. Finally, extensive subsidence above the northern end of the orebody could have disturbed permanent surface installations and jeopardised a possible future open cut. The full implications of this ambitious strategy were not apparent in the early years. Now, after twelve years of production the benefits are being realised and they can be weighed against the costs. Probably the most interesting result which comes from this analysis is the significance of cutoff grades and dilution factors in balancing mining and filling rates.

Jan 1, 1980