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Dealing with Aboriginals and various others purporting to represent them has become part and parcel of exploration and mining in Australia, whereas 20 years ago it was not. The author has been involved in dealings with Aboriginal groups over this period. The following paper is a summary of the social background to such dealings and a compendium of rules for the newcomer to this aspect of the resource industry.

Jan 1, 1990

The mineral sands deposit of Australia pose a number of unique, and quite unusual problems for the explorationist. Most concentrations of heavy minerals have been found in the unconsolidated sediments of the east and west coasts. Mineral sands mines open larger areas per tonne of concentrate than most other mines. This is because of the shallow depth of the sands containing the heavy mineral concentrations. Obtaining tenure can, by mining industry norms, be a massive operation due to the large areas to be examined and, particularly on the east coast, the large number of land holders encountered. A commercial development can still emanate from anything ranging from a small high grade body to a massive low grade deposit, the prices currently being obtained for rutile, zircon, ilmenite and monazite, although still modest when the remarkable properties and applications of these minerals are considered, is nevertheless attractive when compared to the prices being obtained for the base metals with the exception of gold. The current interest in the location and definition of new reserves of heavy minerals reflects this relative price attractiveness. The discovery of heavy mineral concentrates does not necessarily ensure the early establishment of a mine. Because of the cyclical nature of market prices, the average returns likely over the life of the mine permit the employment of only relatively simple, low cost, mining, concentration, and separation processes. If difficult mining conditions are encountered or the removal of small contaminants by complex metallurgical processes are required, then higher market prices must be obtained. Until the market is prepared to pay more for the commodities so produced, the resource will not be economic and lower cost reserves will be mined in preference. The Australian mineral sands industry has seen many closed mines because of past failures to properly assess the data base collected during the exploration and development phases of the failed projects.

Jan 1, 1987

By Zhou A, Cadogan J. M

Direct reduction of iron ore (DR) is one of the promising technology emerging in the world's steel industry. Kinetics and Mossbauer studies of DR with hydrogen have been carried out at two temperatures of 600¦C and 800¦C in this investigation. The results show that different controlling steps govern the reduction rate at different temperatures. The mechanism was also found to vary during the reduction. The Mossbauer spectra of the samples reduced in various time intervals were studied to determine the phase changes during reduction.

Jan 1, 1997

By Larsen E. R

We discuss the concept of optimal cut-off grade policies and their advantages in terms of maximisation of net present value of mining operations. There are indications, however, that such optimal policies are not widely used in the mining industry. In order to explore why this is the case we identify a number of stakeholders who may have diverging interests in the operating policies of a given mine. These various interests are mapped and a number of important relationships are explored in a large qualitative systems dyanmics model.

Jan 1, 1995

Most compact bucket wheel excavators in use are in the small to medium range. Large compact bucket wheel excavators compete directly with con- ventional longer boom excavators which have operational advantages over the large compact. There are, however, situations where the large com- pact excavator is viable. In the development of these large compacts there are a number of technical features to be addressed. In addition the SECV now propose to expand the concept to a large compact bucket wheel excavator with a bridge and loading unit for their Loy Yang Open Cut.

Jan 1, 1989

By Lindner E, Bosio M

South Australian coals are all low in rank and generally poor in quality, with difficult combustion characteristics. This circumstance makes the selection of a fuel source for future power generation difficult, requiring careful study and detailed analysis of the various alternatives. Combustion characteristics can have a significant effect on plant design and costs, and need early attention in any exploration and evaluation programme. The physical location of the deposits, often remote from established infrastructure and centres of population, is also a major factor in the ultimate cost of power at the poirl use.

Jan 1, 1977

Production scheduling is an important element of the mine planning process. The production schedule specifies the quantities of mineral to extract, the source of this ore, the timing of extraction and, where necessary, the quantity and timing of backfill placement. These details are important in linking long-term strategic goals to short-term operational planning. Mine scheduling techniques form the basis for communicating information concerning the overall impact of design and planning changes to a wide range of people at many levels within an organisation. Consequently the techniques used for mine scheduling must support the decision-making process by consistently providing high quality schedules in response to revised and updated data. A new mixed integer programming (MIP) model has been developed to generate optimal production schedules for underground stoping operations. The model maximised the before-tax Net Present Value of the production schedule while satisfying constraints such as contained metal tonnage, hoisting capacity, stope geometry relationships and stope backfilling demands. Zero-one variables were used to represent the decision to extract or backfill each stope in a particular time period. Continuous variables, capable of having non-integer values, were used to denote the quantity of ore or backfill associated with a specific stope in a given time period. A case study is presented to demonstrate the significant improvement in before-tax NPV over a comparative manual production schedule in a large underground mine. The MIP model allows for further modification to reduce solution times and meet the needs of individual mines.

Jan 1, 1995

By Ross C

This paper uses the results of research trials by Landcare Research and Forest Research Institute and assessments of reclamation plantings at mines and other drastically disturbed sites to describe methods of enhancing restoration of native forests. The characteristics of mine and forest environments are compared to highlight the difficulties facing restoration and techniques which result in successful restoration are described. Selection of the most appropriate technique is illustrated by describing restoration of lowland beech-podocarp forest at a West Coast coal mine. The key to successful reclamation is to understand the factors controlling and limiting plant establishment and growth, then to design rooting media, surfaces and management regimes to create a favourable environment. This paper concludes with a summary of the planning and technical factors which are critical for successful restoration of native forest.

Jan 1, 1995

By S France

The Waterview Connection will complete a strategic Auckland motorway route linking the south, west and north. The project will comprise 2.5 km of ‘undrained’ driven tunnels and 900 m of drained cut-and-cover tunnel and portals.The project is aligned beneath a stream valley of Oakley Creek incised through alluvium and in places overlain by landfill, between Mt Albert volcano and a ridge formed in alternating sandstones and siltstones. The hydrogeology of the area is complex with perched aquifers in compressible soils, cascading water levels in fractured rock aquifers, and discontinuous higher permeability units resulting in artesian water levels and groundwater springs.Numerical groundwater modelling was undertaken to assess the potential effects of tunnel construction and long-term operation on the groundwater system; the magnitude and extent of changes in groundwater level and the resulting potential for settlement, buoyancy effects, contaminant migration and adverse effects on creek base flow. Modelling also provides inputs to tunnel design such as groundwater seepage volumes and water pressures.The driven tunnel will be ‘undrained’ long-term so potential effects on the groundwater system are limited to short-term dewatering during construction. Significant project time and cost savings can be made if the portal areas are permanently ‘drained’, but this means potential effects are greatest in the long term condition.This paper summarises the investigations, implications of the complex hydrogeological setting on tunnel design and environmental assessments, and groundwater modelling undertaken during the planning stage of this project. The groundwater modelling has been used to incorporate mitigation options in tunnel design and construction sequencing; a comprehensive monitoring program will be used to trigger appropriate responses should effects differ from those predicted.

Mar 8, 2011

By A Van Kersen, J Hodson

Waihi Gold Mining Co Ltd [WGM], operated by Normandy Mining, has been internationally recognised for its achievements in environmental management at the Martha Mine at Waihi. In a proactive approach to dealing with community concerns regarding blast vibrations on the North Wall cutback, trials were performed using the Cardox System [Cardox], to determine feasibility of achieving economic fragmentation of andesite overburden whilst bettering management levels of 5 mm/s peak particle velocity. Cardox is a non-explosive pressure breaking system which uses high pressure CO2, Results against conventional Ammonium Nitrate/Fuel Oil [ANFO] using a variety of delays showed that conventional blasting techniques could produce marginal fragmentation within the management levels with occasional excursions, whereas Cardox produced the required fragmentation while not registering on the vibration monitoring equipment. Fragmentation to enable normal excavation by a Hitachi EXII00 hydraulic excavator was achieved with a yield of 16m3 per round. The trails indicated that fragmentation with Cardox at the yields required of over 18m3 per round was possible with further product development. The trial demonstrated that non-explosive pressure breaking is feasible and its application warranted where environmental concerns affect the cost-benefit economics of production blasting in sensitive areas.

Jan 1, 2001

By A Black, A de Jo, J Cavanagh, J Harding

Acidic and metal-rich waters have been discharging from Sullivan Mine, West Coast, New Zealand since the closure of the mine during the early- 1990s. This has resulted in a decrease in pH from a background of 4.5 to 2.8 and an increase in metallic elements in nearby Rapid Stream. In addition to the chemical effects on Rapid Stream, a study of freshwater macro-invertebrates revealed the absence of most biota downstream from the discharge. An attempt is being made to use the Sullivan Mine as a case study of problem and remediation analysis.

Jan 1, 2003

During conventional eddy current separation, a repulsive force is applied to metallic particles by placing them in a rapidly changing magnetic field generated by a spinning magnetic rotor carrying an arrangement of alternate magnetic poles. This method works effectively for larger non-ferrous metallic objects, such as aluminium cans, but as the metallic particles become smaller, the bulk repulsive force on the particles is increasingly replaced by a rotational torque. Therefore, for small metallic particles it makes sense to use particle rotation, rather than particle repulsion, to effect a separation. Eddy current separators using particle rotation are similar in construction to present separators, but are designed to produce a rotating field of essentially constant angular velocity and field strength. Practical and economic particle rotation eddy current separations are possible down to particle sizes of about 200 ¦m, but separations, at probably uneconomic rates, can be carried out on particles as small as 50 ¦m.

Jan 1, 2000

The investment worth of a mineral deposit can only be realistically evaluated in relation to specific engineering design criteria, which fully details the proposed method of exploitation. These criteria have not in general been taken into serious consideration when leaseholders have reported reserves in the past. In fact, many "reserve" figures quoted are probably more correctly classified as geological resources. The industry now recognises that it is necessary to take into consideration not only grade and mill recovery factors, but also likely mining and processing costs as well as the current market price for the commodity. Once having estimated those costs which are applicable to the resource under study, they can be deducted from the gross inherent worth of the orebody to result in an estimate of the potential net revenue. Through a process of interactive trial mine designs and evaluation, reserves can be quantified to provide an estimate of the available recoverable economic reserves given a set of assumed cost and operational parameters. It follows then, that the available economic reserve recoverable from a given resource will vary from time-to-time as cost and price factors vary in response to changing technology and economic factors. A methodology is described which may be used to derive economic recoverable reserves based on a computerised model of the geological resource data and appropriate economic and operational cost algorithms. Examples are provided from both coal and gold studies to illustrate the impact of economic criteria on the magnitude of the reserve figure reported for each project.

Jan 1, 1987

Two separate mine rehabilitation programmes carried out by Australian Consolidated Industries Limited (A.C.I.) in South Australia at Normanville and Port Lawler are discussed. Emphasis is given to the methods used, the results achieved and to possible future improvements.

Jan 1, 1976

By Morrell S

As more and more autogenous and semi-autogenous mills are run in closed circuit with cyclones the limitations that can be imposed by poor grate and pulp lifter design are becoming increasingly apparent. Relevant literature on the subject is al

Jan 1, 1997

By Thornton D, Firth B, Kojovic T, Brien G, O&apos

Coal fragmentation is a function of coal type and mining process. Each unit step in the mining, handling and crushing chain of coal imparts energy to the material and impacts on size degradation and consequent mineral matter liberation and pla

Jan 1, 1998

By Koppe J. C, Dimitrakopoulos R, Costa J. F

Grade control and the delineation of ore/waste in open pit operations is traditionally based on the comparison of estimated grades with an economic cut-off. This paper deals with an alternative approach to grade control based on estimating gra

Jan 1, 1998

By Johns AS

Comissioning of a new residue disposal tcluding upgraded classification for none backfill preparation, new variable speed pumps and a new residue dam took place in 1¦76. The system is described.

Jan 1, 1978

By Gomi S

A new watersoluble binder for mineral ore pellets has been developed by the sulfonation of bituminous materials. A highly effective binder for iron ore pellet making is obtainable from bituminous materials produced in the high temperature cracking of crude oils. This paper deals with production process and basic properties of this binder as well as new applic- ations in the field of iron ore pelletizing.

Jan 1, 1974

With the advent of the resources boom in the late-1960s most of the larger scale resources projects in Australasia were commissioned on an æowner miningÆ basis, where the mine owners owned and operated the primary mining equipment. Then, in the 1980s with the arrival of the gold mining boom in Western Australia and elsewhere, a change occurred û most of the mining activities were carried out on a contract mining basis. Over recent years, however, there has been a marked trend amongst larger Australasian open pit mining operations back towards owner-controlled and operated mining operations. The reasons for this are many and are addressed in the paper, but centre on the concept of the owner being prepared to assume more of the mining risk in exchange for the advantage of not having to pay a contractorÆs profit margin. Where mining contracts are entered into, the older æschedule of ratesÆ format is being replaced with less adversarial and more entrepreneurial contract alternatives involving operating cost and risk sharing in a spirit of æfair dealingÆ. Leasing and maintenance issues have also been influenced in recent years by the advent of more flexible contract arrangements with equipment suppliers. Group purchasing has also had some influence for project operators. For many mine owners, the optimal risk management profile involves a practical offsetting of the assumption of mining risk on the one hand, against the removal of litigation risk and potentially reduced operating costs on the other. Potential pitfalls may arise where equipment size and type requirements vary with time or where manpower management, mining flexibility, job skills or safety exposure factors are relevant. These issues are commented on in the context of some well known examples, and an update is provided on contract mining versus owner operation in large-scale Australasian open pit mining generally.

Jan 1, 2002