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By Butcher NM, Walker GS

Argyle Diamond Mines Pty. Limited (ADM), manager and operator of the Argyle Diamond Mines Joint Venture (ADMJV) will recruit approximately 400 employees during 1985 to operate the new large-scale, open-cut diamond mine and treatment plant being developed at Argyle, in the East Kimberley Region of Western Australia. These employees will live in Perth or environs and will commute to work at Argyle via chartered jet aircraft. On site, they will be accommodated in self-contained single person's quarters, with central messing and recreational facilities. Rostering systems have not been finalised, but it is likely employees will rotate through a cycle of 14 days at site and seven-days on leave in Perth. ADM spent three years evaluating residen- tial options before deciding to commute its workforce from Perth. Another 70 senior staff will reside in Kununurra (the nearest established town, 250 km from Argyle) and commute to the mine daily by air.

Jan 1, 1984

By Brenchley R

Partitioning behaviour studies for -particles in the 250 to 1,000 micron size range at. the Curragh coal preparation plant are presented. Plant surveys were conducted to compare the partitioning efficiencies of dense medium cyclones and froth flotation. The aim was to assess the potential for improving yield of coal by directing more of the top size of flotation feed material to dense medium cyclones. ovel mass balancing and model fitting NI procedures were used. While flotation offers high yield of low ash particles smaller than 500 microns, dense medium cyclone rejection .of high ash particles larger than 250 microns is superior. These strengths of the two processes are turned to good advantage by the use or desliming sieve bends which tend to perform some density separation on the'size fractions of interest, directing lower ash material to froth flotation than to the dense medium cyclones.

Jan 1, 1987

By I Sheppard, A Hills

This paper describes a multi-lift bench stoping method introduced recently to extract the narrow silver-lead-zinc orebodies at the Isa Lead Mine. Cut-and-fill methods were chief mining methods for the narrow orebodies at the mine over 35 years ago. Benching methods were introduced approximately two decades later, and quickly replacing the cut-and-fill methods. The benching methods had improved both the economy scale and safety of the mining operation. The multi-lift benching method combines a number of bench lifts into a single stope to further improve the operational efficiency. Three stopes in the initial multi-lift benching trials are described.

Jan 1, 2003

By McNicol J. H

Using a small scale laboratory pilot plant a series of tests have been conducted with the aim of investigating the influence of the zinc/acid ratio on the efficiency of zinc electrodeposition from an acidic sulphate solution. The results have shown that current efficiency is increased as the zinc/acid ratio is increased with no evidence of an optimum zinc/acid ratio. However the choice of a zinc/acid ratio for full scale operations must be a compromise between other parameters, spent electrolyte acidity and power efficiency, which also impact upon plant performance. The effect of various impurities has also been monitored and antimony, nickel and tin have been shown to be deliterious to current efficiency.

Jan 1, 1989

By Jifan X, Yongyu W, Liangjing L

Shallow interception of groundwater is a special dewa- tering form in the specific geological and hydrogeological conditions. It has an economic and technical effect. The roof of the Fankou Lead-zinc deposit is the Hutianqun aquifer made up of the limestone of the upper Carboniferous system. - A "water-bearing basin" is surrounded by the aquifuge and the aquitard below ¦0 m level at the Shiling Hill section in the Hutianqun aquifer. Based on the natural conditions, an interception gallery is excavated at -40 m level out of "the water- bearing basin", the other gallery excavated at ¦0 m level in the poor water-bearing zone of the Jinxing Hill. During 20 years of experience, the better interception effects have been gained.

Jan 1, 1988

Although a small quantity of lc,;v viscosity index ' (L.V.I.) oils are presently manufactured in. Australia, lubricating oil refining methods are assuming gxeater significance since in 1964 Australia will be locally refining the bulk of its requirements and some companies may be exporting a surplus. New plants are ' planned to refine mainly high and medium viscosity index oils from imported crudes and the paper describes typical techniques used òto: produce. thes& oils. .

Jan 1, 1962

The purposes of defining the mining environment for underground mass mining and the uses of characterisation data are outlined. The requirements for data in the areas of geology, surface and groundwater hydrology, topography and environmental constraints and geotechnical studies are identified. Emphasis is then placed on the collection and interpretation of geotechnical data for establishing the in situ stress regime and for rock mass characterisation. Methods used for diamond drilling, core logging, borehole logging, data analysis and presentation, rock mass modelling and rock mass classification are outlined. Finally, recent and potential advances in the state-of-the-art are identified in areas such as geophysical methods, measurement while drilling, computerised data collection and analysis, rock mass modelling, in situ stress measurement data presentation and interpretation, and some applications of rock mass characterisation data.

Jan 1, 2000

By S Pfaff, R Rajic

In the case when the number of independent variables is greater, a careful design for carrying out tests has to be made in order to obtain, with the smallest possible number of tests, as much as possible neutral information about the influence of independent variables on the dependent ones. Only on the basis of such design and its statistical analysis it is possible to come to right conclusions about the function of the whole system. The influence of pressure, temperature, humidity and granulation of the coal upon the resistance to pressure and the water absorption of the briquettes has been tested, with the aim to examine how each of the two dependent variables changes depending on the values assumed by any of the four independent variables and which of the mentioned independent variables significantly influences the dependent ones. The full factorial design with 16 experiments and the central composite design with 27 experiments have been applied. The influence of the independent variables upon the dependent ones has been examined by applying the analysis of variance. The influence values of individual factors and their interaction upon the dependent variables have been stated as well as coefficients of curvilinear equation.

Jan 1, 2003

Since its beginning, with the works of D. Krige and later, G. Matheron, geostatistics has been analyzing in detail the essential factors at play in ore reserves estimation problems, with the ever-present aim of an optimal use of the available information. Not only do the reserves depend on the geological in situ resources, they also require a correct appraisal of many technical and economical parameters. The objective of the present paper is to show how the method of technical parameterization of reserves, which is at the heart of the geostatistical approach, provides an extremely powerful and versatile tool for characterizing a mining project. After a review of the main properties of the technique, its use in the economic optimization of a project will be examined. Two examples from copper and gold deposits will be given.

Jan 1, 1987

By Pease JD, Munro PD

The heavy medium cyclone plant for the preconcentration of silver-lead-zinc ore prior to grinding and flotation was commissioned in August 1982. This paper details the measures taken to get the plant up to design performance which involved modifications to the medium densifying and slimes clarifying sections. Operating experiences to date are described with emphasis on the low medium consumption recorded and severe wear on process equipment.

Jan 1, 1984

By B Shen

The Wambo Rail Spur located near Singleton, New South Wales, Australia, runs for approximately 14 km linking the Mt Thorley rail loop and the Wambo Coal Mine. The project involves a 260 m long tunnel in weathered sedimentary and intrusive materials. The tunnel has a low cover and runs under a main highway. This second paper on the project looks into one aspect of the tunnel in detail: the use of shotcrete arch as the primary support for part of the tunnel excavation. The use of shotcrete instead of steel arch, formulation of the material specification, construction sequencing, installation at the excavated face and material testing for verification related to this facet of the project will be discussed in this paper. The tunnel opened in April 2006, and two years on, we briefly reflect on the impact of this design decision on the overall project.

Jan 1, 2008

Industry can achieve best results via thorough planning, consultatiion with agencies and local communities and a 'hands on' approach to' environmental problem solvingThe Department of Energy and Minerals, through its Minerals Group, has regulatory responsibility for the mining and extractive industries in Victoria. The role of the group is to facilitate the environmentally responsible development of these industries for the benefit of Victorians. It has a wide range of contacts with other government agencies, local government and community groups.The paper is in three parts; firstly, an overview of the nature and contribution of the mining and extractive industries in Victoria; secondly, the industries' regulatory framework; and thirdly, the environmental issues facing the industries and the management of these issues.

Jan 1, 1992

In south-eastern King Island, sediments and lavas of possible Upper Proterozoic to Lower Cambrian age have been intruded by Lower Carboniferous granitic rocks.Within the contact aureole of the Bold Head adamellite north of Grassy the sediments and lavas have been metamorphosed to hornblende hornfels facies grade. The thermal gradient within the contact aureole was small, as the hornfelses exhibit no mineral zoning over a distance of 700 ft from the adamellite.Skarns occur both within the adamellite near its contact with the country rocks, and within the country rocks as partial replacements of three dolomitic limestone horizons. The latter type, the exoskarns, commonly have an andradite-salite mineralogy and carry economic concentrations of scheelite. These resulted from the replacement of carbonate beds due to both diffusion and infiltration metasomatism. Silica, tungsten, minor sulphides, and water were introduced from the adamellite, while aluminium and iron diffused from the enclosing pelitic sediments. Calcium released during marble replacement countered the loss of iron and aluminium in the pelitic hornfelses transforming them to diopside-rich rocks.Endoskarns within the adamellite are the result of two way diffusion across the contact; calcium, aluminium, and iron diffused from sediment to adamellite as silica, potassium, sodium, and water diffused from adamellite to the sediments. From estimates of the lithostatic pressure and mole fraction of CO2, the mineral assemblages of the hornfelses imply that the temperature of metamorphism lay between 530° and 710°C. This temperature range is in good agreement with minimum temperatures, between 610° and 710°C, for the recrystallization of the marbles of the contact aureole, calculated from the determinations of the solid solution of the magnesite molecule in calcite.

Jan 1, 1971

Reverse circulation (R.C.) drilling or the dual tube method as it is quite commonly known, has a unique place in conventional mineral drilling. It can be classified half-way between open hole drilling at the lower end of the scale and diamond drilling at the upper end. The system basically consists of two tubes, one inside the other, with compressed air flowing between the inner and outer tubes. Sample cuttings return up the inner tube through the head of the rig and via a hose to a cyclone where the sample is collected. This system means that the cuttings are free of contamination as they are at no time in contact with the outside formation of the hole.Reverse circulation drilling is divided into two areas: R.C. Roller and Blade for softer formations; and R.C. Percussion for harder formations.

Jan 1, 1986

By Dickerson A. W

The most important mining problem facing many of the established surface coal mines in the Bowen Basin area of Queensland is the rising cost of overburden stripping associated with increasing depths to coal. The Dragline-Hopper-Truck Project is one of a number of responses to this problem, and involves the design and construction of an experimental hopper followed by field evaluation of a dragline-hopper-truck mining system.Such systems, if proven feasible, could be used for a range of applications, eg prestripping, extension of depths for single pass dragline operations and solution of geotechnical problems.

Jan 1, 1992

During 1995 a catastrophic accident took place at the No 2 Vaal Reefs shaft in South Africa, when a locomotive fell onto a cage, causing the death of 104 people. The subsequent Commission of Enquiry found that the safety detaching hook had opened when hit by parts of the falling locomotive, detaching the cage from the rope and allowing the cage to drop 400 m down the shaft. It was believed that had the hook not detached, the rope would have been sufficiently elastic not to have failed, implying that many fatalities may have been avoided. In addition, the risk of accidental opening of hooks due to impact with smaller falling objects in shafts became a concern. This paper deals with a comprehensive statistical investigation that was performed to quantify this risk, establish acceptable levels of such risks and to derive criteria for the resistance of detachment hooks against accidental opening caused by impacts. The investigation involved a survey, dynamic finite element analyses and Monte Carlo simulations.

Jan 1, 2005

By Noreen D

At Bougainville Copper Limited comparison testwork was conducted between "horizontal" cycloning and conventional vertical cycloning. Horizontal cycloning reduces circulating load and allows increased ball mill throughput. Cyclone efficiency is the same or better as a result of the reduction of fines short-circuiting to the underflow. Operationally, horizontal cyclones are less likely to suffer from blocked spigots and high cyclone feed pump sump levels. Cyclone feed pumping power is reduced. High horizontal cyclone underflow density provides the option to optimise grind by manipulating water addition to the ball mill feed.

Jan 1, 1988

The efficiency with which it is expected that a particular coal may be burnt in a power station boiler significantly affects the value of the coal. Consequently many laboratory tests have been developed to provide data on the combustibility of coal. Computer modelling of coal combustion has also provided insight into limits on coal burn- out. Such modelling suggests that burnout of bituminous coal in a power station boiler will be strongly influenced by physical limits on the diffusion of oxygen to the individual coal particles. Coal chemical reactivity appears to be relatively less important. As a consequence of the diffusional limits, significant improvement in burnout is achieved either by producing less large p.f. particles or by providing sufficient furnace residence time to burn the large particles. Field data from a variety of power stations supports these cn.clusions. Burnout was also found to correlate well with volatile content for a number of coals from widely different sources. This is expected as the high vola- tile coals produce less residual char to be burned by the relatively slow heterogeneous Combustion.

Jan 1, 1987

By Collins D. N

The Olympic Dam Copper Smelter Acid Plant is a hybrid plant capable of producing sulphuric acid from either sulphur burning, metallurgical gases or a combination of both. Commissioning of the Acid Plant on sulphur burning commenced in early April 1988 and commissioning on combined sulphur burning and metallurgical gas commenced in August 1988. During commissioning on sulphur burning a number of acid spills occurred due to balancing of tower flows and control of acid dilution. A number of other significant problems were encountered including failure of boiler gaskets, failure of strong acid pumps seals, the fracture of the teflon dilution water injector and the subsequent failing of the acid circulation pump, tank steel failures and various instrumentation problems. The Commissioning of the Acid Plant on metallurgical gases commenced in August and with the exception of the production of oleum in the boiler economizer was relatively trouble free. Oxygen Plant commissioning commenced in May 1988 and was without significant incident. An outline of the basic equipment for the Acid Plant and Oxygen Plant is presented together with aspects associated with the commisisoning of both plants.

Jan 1, 1989

By J Brown, C Roberts

The scope of this paper is to recount the development of segmental linings used in tunnel construction, starting with its inception as an improvement to the brick-lined tunnel approach of Brunel in England and moving through the history and development to the present day, before finishing with a few insights into what the future might hold. The paper also discusses the motivation for the relatively recent move towards replacing conventional steel reinforcing cages with steel fibres and the reasons why steel fibre reinforced concrete (SFRC) is rapidly becoming the material of choice for manufacturing precast concrete segmental linings.

Jan 1, 2008