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By Fulton E, Ring RJ, Waters DJ

Laboratory leach tests of Nabarlek uranium ore carried out by the Australian Atomic Energy Commission to compare the effectiveness of Caro's Acid1 (permonosulphuric acid) as an alternative oxident to pyrolusite indicated reduced acid consumption in leaching and lime savings in neutralisation of tailings liquors when using Caro's Acid. Interox Chemicals Pty. Ltd. arranged a plant trial for Caro's Acid at Queensland Mines Nabarlek Plant. The trial confirmed that significant savings in acid and lime can be achieved under plant conditions. Plant operations also demonstrated improved redox potential control was possible using Caro's Acid.

Jan 1, 1978

By Callaghan R. P

Underground production from the low grade copper orebodies at Mount Lyell in recent years has involved surface subsidence of open cut areas. Relevant structural and lithological features of the geological environment are des- cribed. The highly mechanised underground mining system involves sublevel caving and sub- level open stoping with associated hangingwall cave. Monitoring of subsidence and caving has been made by regular visual inspection and measurement of crack development, and by sur- face profile surveys. These simple techniques have proved adequate in assuring management that ground movement is proceeding normally and safely.

Jan 1, 1980

The preferred alternatives in heap design and their motivation are identified as- -normal heap leaching, to be generally applied wherever possible, - flooded vat leaching, to be appliedwhere wetted ore lacks adequate cohesion or if limited space necessitates it,- thin layer leaching, to be applied where deleterious vat chemistry necessitates it.A number of the following features would probably be incorporated in the optimization of normal local heap leach operations- pre-cyanidation - pre-agglomeration - retaining walls- staged (counter-current) heap treatment- control of calcium levels- reduced pH and trickler irrigation

Jan 1, 1984

By Clift N

Lead concentrate from the Isa and Hilton lead-zinc concentrators of Mount lsa Mines Limited is smelted at Mount Isa to produce a lead-silver bullion. This bullion is cast into four tonne blocks and shipped to Britannia Refined Metals Co Ltd, NorthDeet, England and to plants in Asia for refining and marketing. The traditional treatment stages at Mount lsa are sintering, smelting, and drossing and casting, with some of the sinter plant feed being pre-treated through an Isasmelt plant.A commercial scale lsasmelt based lead smelter was commissioned in early 1991.

Jan 1, 1993

By Moore A. J

Blasting in mines in an urban environment can be conducted safely and within regulatory vibration limits by careful attention to detail and the application of correct techniques. Factors affecting blast vibration are described using surface and underground mining examples. An understanding of these factors provides an essential base for effective planning and operational control. Techniques are described for assessing and predicting vibration levels and the presentation of data for planning purposes such as environmental impact statements for new projects and the protection of buffer zones around existing operations.

Jan 1, 1997

Mining software systems have provided a basis for integration of resource, survey, and design functions. They can similarly provide a basis for incorporating ground conditions into the process.Exploration and mine geologists have a prime role to play in this process, extending their responsibilities further across the geological spectrum, into exploration of ground conditions, analyses of results, and assessments of their implications for mining. Ground conditions are as much a part of the geology of a prospect or mine as its mineralisation, and can have critical imnlicationa for mining.

Jan 1, 1993

Sublevel open stoping (S.L.O.S.) was introduced at Rosebery in 1972 in the wider ore blocks below 14 level, largely replacing cut and fill methods which had been in use up till that time. During 1973/74 the method produced 10% of primary stoping tonnes, and by 1981/82 it increased to 65%. Because of the increasing reliance placed on sublevel open stoping for primary stoping production, every effort was made in both planning and operating to: - maximise ore recovery and reduce dilution - increase productivity - reduce costs.

Jan 1, 1982

The increased cost of imported oil fuels, coupled with our understandable reluctance to commit ourselves to the use of nuclear energy, has resulted in a renewed reliance on coal as a primary source of energy. New Zealand is fortunate in being fairly well endowed in its coal resources, but their exploitation until now, has been on a relatively small scale. Future exploitation, whether from underground or open cast mines, must be on a very much larger scale. This paper outlines some of the factors which should be considered in planning large open cast mines.

Jan 1, 1976

Diversity is a key strength for Western Mining Corporation. An international corporation with assets of about $A10 billion, WMC is engaged in both mining and downstream processing of minerals including nickel, gold, alumina, copper and talc, as well as having interests in oil and gas production and agricultural fertiliser. The company is focusing on several core commodities that will maintain its strength in the years ahead. Although most current mineral assets are within Australia, it plans to have 25 per cent of its operations off-shore by the turn of the century, and be a major producer in at least six core commodities. WMC's strategic and management focus has shifted from a regional approach to a commodity focus so that it can more readily cater for different markets with differing sensitivities. This document is an ABSTRACT ONLY - no paper was published for this presentation

Jan 1, 1996

Robe River Iron Associates (RRIA or Robe) is widely regarded as the worldÆs most cost-effective, consistent and reliable supplier of iron ore. It has been in operation since 1972 and globally is the fourth largest seaborne trader in iron ore exporting 25.5 million tonnes of -9.5 mm sinter fines and 4.5 million tonnes of pisolite lump (-31.5 +6.3 mm) during 1999. Robe is a joint venture that controls major iron ore resources in the Pilbara region of Western Australia. ItÆs participants are North Limited with an interest of 53 per cent (65 per cent including minority interests) and Japanese companies Mitsui (33 per cent), Nippon Steel Australia (10.5 per cent) and Sumitomo Metal Australia (3.5 per cent). Robe River Mining Co Pty Ltd manages the project which is a subsidiary of North Limited and Mitsui.

Jan 1, 2000

As part of a prefeasibility study being undertaken by Newcrest Mining Limited, the Cadia East Implementation Team has developed an access decline to the proposed underground operation. This paper describes new technologies that have been employed in this development, which include: high frequency drifters that have penetration rates one and a half times that of competitors, ensuring minimal increase in drill time, despite rounds greater than 5.5 m;automated drilling used in conjunction with laser navigation and face pattern design software, which facilitates exact positioning of hole collars, lengths and lookouts for accuracy and repeatability; andemulsion charging that reduces manual handling; has variable string loading capabilities, via its hose retraction system, for perimeter control and reduced fume characteristics. A Six Sigma improvement process was used to support the system change undertaken and demonstrated that development rates improved 60 per cent above the comparable single heading benchmark.

Jan 1, 2008

The estimate of an ore reserve is a vital statement made about a mineral occurrence by an evaluator. It is important that such a statement communicate reality to all groups involved in a mining project, be they technical, financial, company directors, Stock Exchanges or the public. Ore reserve statements should state both resources and recoverable ore reserves. Resources may be important in very long term considerations, (because mining, metallurgical technology and economics change with time) but recoverable reserves are todays reality. The important factors contributing to recoverable reserves (in a general sense) are geology, mining method (and its impact on dilution and ore loss), metallurgical recovery, costs and commodity prices. These all need to be reflected in the ore reserve statement. In this paper recoverable ore reserve concepts across a wide range of orebodies are considered and discussed with respect to geology, mining method and ore reserve calculation procedures.

Jan 1, 1987

Basic premises for evaluating special characteristics of gold-bearing porphyry metal systems stem from their contrasts with properties of the class as a whole. Included features are differences in geologic, thus tectonic, environments, subtle but real differences in the proportions of accessory metals Mo-Ag-Au that are regionally and within some regions, tempo-rally distinct, contrasts in the Ag:Au ratios, petrological-geo-chemical as well as isotopic differences between intrusive suites, the age and nature of host terranes, contrasts in alter-ation style, and zoning variations of mineralogical and physical properties of rocks. These properties are linked in various ways in different regions and suggest that in large gold-bearing systems where gold may be uniformly distributed, environ-ments of emplacement, and compositions or sources of igneous "progenitors" may dominate in importance over processes, and that systems in which gold is zoned are processes-dominant.

Jan 1, 1990

The program, WASTRT 70, was set up specifically to handle the design of tunnel liners and underground structures where inter- action between rock and structure significantly affects the design. It may however be used for any mass/R.C. structure capable of being simulated by straight line elements between modes and with loading restricted to nodes. The analysis system adopts typical elastic/stiffness matrix methods. Two main mass/R.C. design segments are utilized (1) Design of section depth based on maximum required stresses and optimum steel/concrete ratios. (2) Design of reinforcement for a given section depth with concrete stresses given for mass and water code structures. Each design segment covers shear, minimum principal stress on ~ , heavy compression as per code (columns), heavy compression one-face steel (tunnel liners), tension and water code requirements for all moment/thrust/section depth ratios on rectangular sections.

Jan 1, 1976

By Finch JA, Uribe-Salas A

The relationship between the process variables and hydrodynamics of a downflow concurrent column (Jameson cell) was investigated in both two and three-phase systems. Gas holdups from 10 to -60 per cent were obtained at gas rates up to 15 cm/s (STP), liquid (slurry) rates up to 25 cm/s, frother concentrations of 5 and 25 ppm, and slurry density (silica) up to 1.23 g/cm3 ina 3.8 cm diameter, 190 cm high column with a 0.5 cm diameter nozzle. Gas holdup decreases with feed rate and increases with gas rate, reaching a maximum (-60 per cent) at a gas rate to feed rate ratio of about one. Gas holdups were higher with slurry compared to water as feed. Stable operation was difficult to maintain at high gas rates especially with low frother dosage; operation was not possible without some frother. Instability was characterised by loss of pool level or formation of slugs. The slugs could move up or down or remain oscillatory. A quantitative relationship between the variables and gas holdup or onset of instability was not identified. Conductivity and pressure-based techniques were successfully tested on-line for estimation of gas holdup and to judge the state of operation (eg formation of slugs).

Jan 1, 1993

By M F. Lee

In order to make good decisions, as to whether large diameter raise bored shafts can be constructed in blocky rock at a particular location, mine planners, management, geotechnical engineers and contractors must understand and consider a range of geotechnical issues. Firstly, mine management must ensure that adequate time and resources are available to find appropriate shaft sites. Deep weathering, adverse structures, groundwater, etc might mean that the most desirable location, with respect to other mine development, might not be suitable. Special site investigation drilling, etc may be necessary. Even then, alternative construction options might be necessary, other than just reaming through to the surface. A site investigation borehole should then be drilled to investigate specific and general ground conditions along the raise alignment. Often, only small sections of weak blocky rock dictate raise stability. While the empirical McCracken and Stacey method is typically used in Australia to assess raise stability and assess geotechnical risk, until recently it had no published performance data.An Australian database of raise performance now exists and is presented below, courtesy of an industry survey by the Eastern Australian Ground Control Group. Raise diameter and ground conditions (in terms of a lower bound Qr value) is presented for 50 cases versus raise performance.

Jan 1, 2008

By Haukka M. T

A new low-dilution fusion method which has been successfully used for accurate determination of the major oxide components of silicate rocks, is applicable to rapid, accurate determination of trace or minor eiements in mineral exploration samples. Limit of detection is in many cases less than 5 ppm. Either rapid, approximate measurement and calculation methods (suitable for geochemical exploration), or more accurate methods (applicable to orebody evaluation studies) may be used.Rapid methods are described for nickel in rocks and sulphides containing 10 ppm to >2 per cent Ni, and for gallium. The rarely-determined element gallium is an example of a constituent which may be easily investigatedby XRF using the LiB02 fusion disc, which is a permanent, easily-stored analytical sample available for later rapid or accurate analyses. The method is applicable to over 30 elements at levels encountered in mineral exploration.

Jan 1, 1978

By Bayly MG, Harris JA

The current operational practice at the Territory Enterprises Pty, Limited uranium oxide plant,, and some aspects of researc$ and development work at Rum Jungle are outlined with pertinent comments on some overseas practices.

Jan 1, 1968

By L Barro

There is currently a worldwide interest in coal-oil technology as the search continues for alternative energy sources to reduce the consumption of petroleum crude. An important aspect of this coal-oil technology study is to obtain information on the flow properties of coal-oil slurries. While some work has been reported on the flow behaviour of black coal-oil suspensions, very little work on brown coal-oil suspensions has been reported. In this paper flow characteristics of brown coal-oil suspensions for various coal concentration and temperatures have been presented. A capillary rheometer, designed to handle settling suspension, has been used for determining rheological properties. Brown coal of 0.0725 mm average particle diameter has been used in this work. The oil was a coal derived product having a boiling point range of 234¦C - 319¦C. Apparent viscosity of all suspensions was found to increase on storage due to ageing. Ageing might have occurred due to physicochemical interactions between coal and oil. Flow behaviour of some suspensions changed from Newtonian to non-Newtonian on storage. Apparent viscosity increased sharply with increase in solids concentration and suspensions at higher concentration behaved as non Newtonian liquids. Viscosity decreased with increase in temperature; rate of decrease slowed down with increase in temperature.

Jan 1, 1980

Mineral exploration and mining in New Zealand has had almost five years of new legislation. The requirement for different consents is a challenging, time consuming, expensive exercise but in most cases the new procedure is working, although the matter of obtaining access to land is still a major issue. Priority is critical. After lodgment of an application for a minerals permit there are many other matters to address such as identifying land owners, occupiers and administrators, preparation of access applications, consultation and preparation of various resource consent applications.

Jan 1, 1996