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By R Milton, D Hake, H Sprague

The North Western Sewer tunnel extends over 11.5 km in the North Western suburbs of Melbourne.The $253 million tunnel project provides a critical link in the Melbourne Sewer Network. The existing sewers fail to service the increasing demands of the growing population of the North West regions of Melbourne. This project will protect the environment and improve the standards of service of the existing system. This paper concentrates on Section three of this project, consisting of the final 4 km of the Contract, three access shafts and a cut and cover section of tunnel.Transfield Tunnelling as Head Contractor constructed the tunnel for Melbourne Water Corporation, with Enetech Streamline, formally Streamline Australia, a trading arm of Melbourne Water acting as Superintendent.Excavation of Section three of this project commenced in September 1994 and project completion is scheduled for October 1998. The tunnel passes below the residential suburb of Essendon, through some of the most challenging ground conditions ever attempted to be tunnelled in Australia.

Jan 1, 1999

By Shonhardt JA, Bagster DF

This paper firstly examines the pollu- tion potential of burning colliery wastes. A comparison of two means of estimating the pro- pensity for coal to combust spontaneously is next presented. The use of microwaves, as a new procedure, is discussed in detail, while a comparison of the results is made with a modi- fied adiabatic technique. A number of coals that are known to combust spontaneously was tested, as were some coals that are not consi- dered to have self heating potential.

Jan 1, 1987

By A Benedictus, A Butcher, J Wikstr÷m, B Lindblom, E Rutqvist

LKAB is a mining company situated in northern Scandinavia, manufacturing blast furnace- and direct-reduction pellets and sinter fines. Pellet development at LKAB comprises testing at laboratory and pilot scale. The LKAB Experimental Blast Furnace (EBF) is a unique test facility and an important tool in terms of product development and process research. For a better understanding of pellet behaviour in the blast furnace process, LKAB has started to use automated mineralogy for the characterisation and quantification of its iron ore products and pellets. A mineralogical evaluation of iron ore olivine pellets, taken from a test campaign in the EBF, has been performed. The studied materials were samples from excavated pellet layers through the entire EBF at different positions. A large number of iron ore pellets was analysed using a combination of automated mineralogy, using QEMSCAN«, and chemical analysis. Important information about the performance of pellets in the blast furnace process, such as a quantitative description of mineral and iron oxide alterations at different temperatures, Fe-reduction and alkali deposition, was obtained.

Jan 1, 2008

By Semple DG, Leach TM

A continued exploration programme has further defined the geology of the Tolukuma vein system, verified the resource indicated by Newmont, and identified potential for additional mineralisation. The resource at Tolukuma Hill, designated as Zone C, is a measured 440,000t @ 17g/t Au and 46g/t Ag with an additional indicated resource of 120,000t @ 16g/t Au. A diatreme breccia localised at an intersection of structures, and a relationship of gold to base metal sulphides, are highly indicative of a porphyry association. Typical epi-thermal features such as crustiform banded quartz and quartz pseudomorphing. platy calcite are also present and locally contain lesser gold mineral-isation. Pre-existing dilatant structures have acted as a host to the ore fluids, resulting in the formation of the semi-continuous Tolukuma-Gulbadi veins over a 1100m strike. A fluid flow model suggests that mineralising fluids were sourced from the diatreme margins and migrated laterally along dilatant structures. Bonanza gold grades are derived through fluid quenching in the flexure between a hanging wall split which hosts much of the Tolukuma Hill resource and the feeder graben structure. Thus, the relationship between the pre-mineral structural geometry and fluid upflow at the margins of a diatreme breccia, controls the ore setting. Potential for more ore remains within the Gufinis and the 120 veins as well as in the outlying Prospects.

Jan 1, 1994

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 Brasnett TC

A wide variety of problems are encountered on a day to day operating basis in the Isa Mine Concentrators. These vary from complex textural problems in the lead-zinc concentrator and their subsequent effect on grinding and flotation to scheduling of converter slag treatment in a chalcopyrite concentrator. With the advent of process control, metallurgists need to specialise and keep up to date with technology improvements. This paper will attempt to describe the significant problems'faced by a Metallurgist û Control.

Jan 1, 1978

By Gordon A. R

The effect of various types of solid carbonaceOlls reductants on the rate of fuming of zinc from lead blast furnace slag was investigated at I250°C.The results of the laboratory experiments indicated that the rate of removal of zinc from slag depended primarily on the volatile matter contents of the reduclants. The effects of fixed carbon, moisture and ash contents were less significant.

Jan 1, 1992

Electron paramagnetic resonance provides a fast method to characterise quartz. Quartz from veins associated with the Cambrian massive sulphide deposits in the Mt Read Volcanics of western Tasmania and from Devonian reefs associated with gold mineralisa- tion at various localities in Tasmania exhibit specific EPR patterns, different from quartz from common veins. The intensity of the EPR spectra of the quartz can be used as a statistical guide to gold mineralisation at Beaconsfield.

Jan 1, 1987

Construction of Western Mining Corporation's nickel refinery at Kwinana, Western Australia, commenced in July, 1968. Production of 15,000 tons per annum of refined nickel metal will commence early in 1970, The plant will also produce approx- imately 150,000 tons of ammonium sulphate0 The ammonia leach process which was developed by Sherritt Gordon Mines Ltd., and has been in operation at their plant at Fort Saskatchewan, Alberta, Canada, for the past 15 years, will be used at Kwinana. The refinery will cost approximately 435 million, and will employ upwards of 250 people.

Jan 1, 1969

By Collins AR, Meares RMD, Graham JM

Exploration programs for both alluvial (placer) and hardrock platinum group metal deposits are being conducted in Papua New Guinea by a joint venture between Degussa AG and Pancontinental Mining Limited. Prospective areas were defined on the basis of ultramafic/ophiolitic source rocks shedding detrital platinoid grains. Field sampling techniques including churn drilling, together with appropriate laboratory analytical and mineralogical techniques, were developed and are contributing to the success of the exploration programs.

Jan 1, 1987

By Trudinger JP

Mt. Newman Mining Company Pty. Ltd.3 oper ates the Mt. Whaleback iron ore mine in the Ham- ersley Iron Ore Province of Western Australia. The present rate of production of high grade hematite iron ore is 33 million tonnes per year. Mining is by open cut quarrying,with 15m high benches. The present quarry operations will be extended to a large oval pit to win over 1400 million tonnes of iron ore. The pit slopes will extend up to 500m in depth and the perimet- er of the slopes will exceed 15km. Sixty per- cent of the ore is below the water table, which presently lies 45m below the general plain level Dames & Moore, rock mechanics consultants designed the pit slopes during early mine devel- opment to ensure an economic and safe operation.

Jan 1, 1975

By I Grant

On the 1 June 1978, the Town and Country Planning Act 1953 was replaced by the revised and more comprehensive Town and Country Planning Act 1977. The new act brings in some substantial changes to the law affecting regional and district planning, and for the first time makes provision for maritime planning. The importance of the Town and Country Planning Act 1977 to the Mineral industry is primarily in the relationship between Regional Planning Schemes and District Schemes as the needs and resources identified in a Regional Planning Scheme will override the underlying District Schemes. The mineral extraction industry must be recognised as a regional responsibility which draws on the resources of a region to satisfy the demand of the communities within that region rather than a purely local operation within one District.

Jan 1, 1978

By Bowdler RJ, Lowson RT, Sarbutt JV

There have been few long-term studies of sulphide oxidation under controlled conditions. The object of this study was to investigate the oxidation and leaching characteristics of pyritic mine material under conditions that were commensurate with field conditions but which could be controlled and monitored on a long term basis. The test material - overburden from Woodlawn Mines Pty Ltd - was packed into a 300 cm high column and leached with water at an infiltration rate of 256 mm y-1 for 5 years. Chemical conditions within the column were continuously monitored by sensors embedded in the overburden and leachate from the base of the column was analysed weekly. The study examined the relationships between heavy metal release and gas, moisture, and chemical conditions in the column.

Jan 1, 1988

Coal pillar design has been based on generalised formulae of the strength of the coal in a pillar and experience in localised situations. Stress measurements above and in coal pillars indicate that the actual strength and deformation of pillars varies much more than predicted by formulae. This variation is due to failure of strata surrounding coal. The pillar strength and deformation of the adjacent roadways is a function of failure in the coal and the strata about the coal. When the pillar is viewed as a system in which failure also occurs in the strata, rather than the coal only, the wide range of pillar strength characteristics found in the UK, USA, South Africa, Australia, China, Japan and other countries are simply variations due to different strata-coal combinations and not different coal strengths.This paper presents the measured range of pillar strength characteristics and explains the reasons. Methods to design pillar layouts with regard to the potential strength variations due to the strata strength characteristics surrounding the seam are Presented.

Jan 1, 1998

The beneficiation of heavy metal oxides, such as iron ore, is usually performed with heavy medium separation in cyclones, static baths and lately with Larcodems. Atomized ferrosilicon is most suitable as a heavy medium at densities above 3600 kg/m3 whereas a mixture of milled and atomized ferrosilicon is suitable at densities below 3600 kg/m3. When operating a beneficiation plant at densities higher than 3600 kg/m3 the quality of the ferrosilicon particles is an important factor that influences the control of the beneficiation process. Therefore, it is important to know how the rheology would be affected by the ferrosilicon quality as it also influences the control of the process at these elevated densities.

Jan 1, 2002

Feasibility studies in the development of mining projects are fundamental to most investment decisions. It is important that the issues addressed and the degree of detail involved in feasibility studies are consistent with the investment decisions to be taken. Emphasis should be placed on a thorough analysis of critical project parameters prior to detailed investigations being undertaken into other activities which are not relevant to the decisions at hand. Therefore, the issues to be decided upon should be influenced significantly by the stage of development of the project and by the reliability of technical and financial information used in the study. Some of the more critical parameters of feasibility studies are commodity prices, inflation rates and discount rates. Advice is given on the selection of these inputs and also on their application in the feasibility study as the project progresses through its various development stages. The feasibility study should involve not only a formal evaluation of project economics but also an analysis of all project related risks and a comparative analysis of projects competing in

Jan 1, 1983

By Jiricek F

Legislative change has reformed the licensing process in Victoria. The Mineral Resources Development Act 1990 and the two stage system of licensing with the authority to commence work is discussed. A key part is the requirements of planning consent, being either an Environmental Effects Statement or the issue of a Planning Permit prior to the issue of an authority to commence work for mineral extraction. Examples of recent experience is discussed.

Jan 1, 1997

Within the Business Process Improvement Program initiated at Placer Dome during 2003 was the Business Performance Management Project (BPM).BPMÆ s aim has been to extract productivity improvements from individual business units by providing a model for implementing leading practice based management process within the Placer Dome Group, sharing management best practice, injecting new management techniques and instilling a continuous improvement culture. The installation of an underground dispatch system has been a key component of the BPM project at Osborne Mine.Information capture and analysis allows for corrective action to be planned and executed before there is a material impact on the performance of a business unit. This paper briefly describes the principles and practices of effective business performance management, the four processes of a management operating system namely; strategic and tactical planning, implementation and reporting. The identification of business drivers, their measures and associated key performance indicators is discussed. The benefits of an underground dispatch system at Osborne with respect to safety, production and maintenance is described along with the installation process within the mining department that included its configuration, resourcing and roll out.

Jan 1, 2005

In early-1989, subsidence due to voids at the top of previously filled stopes and stopes awaiting filling,began to threaten the 15 level fill conveyor horizon. This together with the need to maintain production targets meant that a method was required to significantly increase fill placement.Alternative methods of placing dry fill underground were investigated. One option was to drill 200 mm boreholes from surface directly into stopes 600 - 800 metres underground. A drilling program was successfully undertaken, and resulted in the placement of more than 800 000 tonnes of dry aggregate fill via four boreholes.This paper details the drilling program undertaken and discusses the difficulties encountered, the fill placement system and the project costs.

Jan 1, 1992

Geologists often classify ore textures on the basis of the origin of the rock in which they form and the grade of one or more minerals within the ore (Sinclair and Blackwell, 2002, pp 32-36).  Metallurgists, on the other hand, need to know how best to process the ore in order to extract the valuable minerals from it (Petruk, 2000). Geological classification has the following disadvantages:it requires the services of skilled economic geologists, of whom the supply has been dwindling for many years;it is subjective, depending on the perceptions of the individual geologists who make the classification; andit may relate only weakly to processing requirements of the ore. We describe methodology for automatic classification of ore textures from images of drill core. The images analysed are æclassifiedÆ images, in which a particular mineral (or mineral group) is assigned to each pixel. The new methodology is intended to:provide a quantitative and reproducible alternative to traditional geological texture classification,relate to process mineralogy of the ore, andimprove the ore-texture-related input to orebody domaining and geostatistical block models.

Jan 1, 2008