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The prime requirement is market, which for NZ inevitably means overseas markets. In order to be internationally competitive, the economies of scale and mechanical handling are essential. Since significant markets have not been sought, the full extent of our industrial mineral potential is not known. In general the technology exists to impart the desired quality, but at a price. Price is the main constraint, which may confine truly competitive operations to coastal situations to avoid high internal freight charges. Some commercial deposits of construction materials are being sterilised by zoning, making the costs to the consumer and country unnecessarily high. Unless management is enlightened and marketing is forceful, it can restrict growth. There is a good case to mount a search for phosphate minerals. The main growth areas are likely to be direct shipping ores like limestone, silica sand, and olivine, but in particular pumice.

Jan 1, 1978

This paper examines the interplay between longwall support design/geometry features, operational controls and geological features on ground response. Experience from several investigations is used to demonstrate the influence of factors such as longwall support capacity and geometry, setting pressure, coal seam strength and stiffness, tip-to-face distance and hydraulic supply and control system parameters on longwall ground response. These factors are then used to outline the requirements on key controls such as retreat rate and cutting height and their influence on allowable roof convergence. The ground response curve concept as a means to provide graphical representation of longwall support and strata interaction processes is presented. The approach was developed to address the requirement for a practical longwall support evaluation and selection tool that can take account of support load influences such as changes in roof geology or cover depth. An example of the comparison between single pass longwall and top coal caving in a thick seam environment is given to demonstrate the influence of the various factors discussed.

Jan 1, 2005

The increasing introduction of high capacity mechanical equipment into the coal mines of New South Wales following. tforld War II brought with it problems of roof support. Rapidly advancing headings in difficult country could not be supported with heavy, close,timbering due to the time involved in installation and the reduction of available' space for the movement of machines. _ The installation of low cost, space saving, rapidly installed roof supports became a necessity if the new mechanical equipment wa-s to be allowed to operate at maximum efficiency. As, a result of experience in the United States of America, the system of roof support using steel reinforcing bolts began to find increasing, popularity in the mechanised mines in this State. From the somewhat'crude methods of in- stallation adopted in some of the, early trials, the practice of roof bolting has advanced into a-highly technical operation, requiring care and skill to ensure optimum results.

Jan 1, 1971

By Nag D. K

The Dolphin Scheelite orebody is located near the old mining town of Grassy on the south-east comer of King Island in Tasmania. Surface open cut mining of the Dolphin deposit was conducted for a number of years, then the proximity of the sea and adverse stipping ratio led to underground mining. As a result of the variable orientation and dimensions of parts of the orebody a number of mining methods were practiced at the Dolphin mine until 1990 when a combination of high processing and surface site costs coupled with low tungsten prices led to the cessation of operations. In this paper the different mining methods practised are examined and critically reviewed. The more successful mining methods were developed with experience and improving equipment technology to the extent that the underground operation produced ore at the lowest unit cost during the final years of operation.

Jan 1, 1995

By A Coulson, J Hussey

Noranda Inc is a Canadian mining and metallurgical company with its activities managed through businesses in copper and recycling, zinc, aluminum, magnesium and various metals through its interest in Falconbridge Ltd. Noranda operates three base metal mines, three copper smelters, one copper refinery, one zinc refinery, one lead smelter and refinery, three copper recycling and sampling facilities seven aluminum producing facilities and one magnesium production facility in the construction stage. The mining side of Noranda has a strong history of open stope, cut and fill and shrinkage mining. The 1999 Noranda Annual Report lists a 206 million tonne resource located at Porphyry Mountain in GaspT, QuTbec. Mont Porphyre is a large tonnage, low-grade porphyry style Cu-Mo deposit that was discovered in 1994. It is located at a depth between 1.0 and 1.7 km below surface and characterised by a very competent rock mass. The Mont Porphyre resource is located adjacent to the town of Murdochville, close to NorandaÆs Mines GaspT operations. Mines GaspT closed its open pit and underground operations in 1999 after approximately 45 years of mining, but still operates a copper smelter near Murdochville. The low-grade and great depth of the Mont Porphyre resource suggested that mine design could not be based on the conventional Noranda open stoping mining practice. This paper will review NorandaÆs approach to evaluating the Mont Porphyre deposit. The approach included two definition diamond drilling campaigns, a review of current caving practice, an in-house scope study, a geotechnical logging program for diamond drill core and participation in an international study on cave mining. One interesting component of NorandaÆs approach was the scope study that involved a team of multi-disciplinary personnel drawn together for a short period of time. The objective of the scope study was to determine what conditions would be necessary to mine the deposit and to assess the merits of continuing with further exploration work. A review of current worldwide underground bulk mining practices, and in particular an evaluation of the applicability of caving mining methods, were key components of the scope study. The scope study team concluded that derivatives of caving could be applied to the mining of Mont Porphyre, but additional diamond drilling was recommended to further define the deposit and improve the level of geotechnical information. Following the recommendations of the scope study team, a diamond drilling campaign was completed during the summer and fall of 1997. The 1997 drilling campaign had two secondary objectives, in addition to the primary objective of defining the limits of the orebody. The first objective was to improve the level of geotechnical information available for the characterisation of primary block cave fragmentation. The second objective was to improve the delineation of a lower grade intrusive core. A geomechanical investigation was conducted and included particular emphasis on geotechnical data collection and analysis. A review of the actual data collection process, including several trials of different core orientation techniques, will be included in the discussion.

Jan 1, 2000

By Collins J. L, Fytas K

Surface mining accounts for more than 50% of the world's total mineral production. In future years this status is expected to change somewhat in favour of surface mining. The production technology during the past decade has concentrated on greater degree of mechanization with high capacity heavy duty equip- ment. This trend will continue. Next two decades will also see microproces- ,or based equipment, health and performance monitoring and management information systems fully integrated with excavated and material handling systems which in themselves will be amenable to auto- matic and remote control. Computerized mine planning will also be integrated within the system providing a fully integrated planning, excavat- ing and materials handling system. The surface mines of the 1990's and beyond will be so computer dependent that manpower will be reduced to one third of current levels.

Jan 1, 1988

A major problem in the continuous casting of aluminium killed strip steel is the incidence of black and grey lines in the strip surface caused by the alumina inclusions. One place for limiting the number of alumina inclusions is by providing favourable fluid flow conditions in the ladle so that the inclusions float out to the surface or adhere to the ladle wall. In laboratory equipment 20 kg of steel was melted in an alumina crucible of 14 cm diameter in an induction furnace. Deoxidation was carried out while the melt was constantly stirred by argon bubbling. Bubble frequencies were measured at the lance tip using a microphone technique. High speed cine photo- graphy was incorporated to measure melt top surface velocities. Experimental results indicate that the rate of removal of inclusions is a function of both the gas input and the power input. However due to unfavourable surface area to volume ratio, reoxidation of the melt took place. Some other experimental difficulties in working at high temperatures are also discussed such as lance design, melting arrangement and sampling techniques.

Jan 1, 1984

Roller seed screens were installed at The Broken Hill Proprietary Company Limited (B.H.P.) Whyalla pellet plant to replace vibrating screens on the green ball circuits. The installation of roller screens was justified by improving the sizing of the green balls. This improved sizing increased the yield of fired pellets produced from green balls thus decreasing the fuel consumption. The fired pellet sizing was improved also. This paper discusses the configuration of the roller screens installed at Whyalla, quality of green balls produced, advantages of roller screens compared with vibrating screens and future development of roller Screens.

Jan 1, 1984

By Northcote GG

There are many underground mines with shaft or decline access with limited production capacity or where the mine may become uneconomical as trucking costs escalate with increasing depth of the decline. In such cases a need may exist for a shaft hoisting system which can be constructed more quickly and more economically than a shaft sunk by conventional methods. Relatively cheap small diameter shafts can be constructed by raise boring. This paper describes a simple hoisting system which has been designed to take advantage of the benefits of raise boring. The system uses twin bored raises with a double drum winder hoisting a skip in each hole. The design concept is based on 1. accepting that the raises cannot be truly straight or vertical, 2. using the raise to guide the conveyance, and 3. minimising operating, maintenance, and capital costs. The hoisting system requires a certain degree of accuracy in the alignment of the twin raises. A survey of raise boring practice showed that the required accuracy could probably be achieved with conventional techniques. However it was thought it would be necessary to survey the pilot hole during drilling and to be able to correct the hole if deviation became

Jan 1, 1978

The relevance of borehole and bore core evaluation to the design of underground coal mines is illustrated by considering the technical parameters of colliery design and the information from which they are constructed. The nature of this information is described, together with some methods for its storage, processing and presentation. Geophysical exploration techniques are compared as information sources. It is concluded that borehole and bore core evaluation is relevant and necessary for colliery design, but that optimum results will be obtained if drilling can be combined with geophysical techniques. Because of the inherent uncertainties in prediction of mining conditions the necessity of obtaining as much information as practicable from drilling evaluation is also stressed.

Jan 1, 1977

The use of the heavy media cyclone (HMC) Separation process for the treatment of ores in a particular size range is comparatively new to Australia. The paper describes briefly the principles of HMC operation. Reference is made to early development work, the pilot plant trials and the acceptance of the technique as a mineral dressing process. The Mitchell Cotts pilot plant at Amdel is described briefly and the results of test work on this unit for the processing of a wide variety of ores and ore types are given. Comments are made on the ob- jectives aimed at in the investigation and results are discussed with particular reference to behaviourial differences between ore types. The process is easy to operate, possesses a high capacity-to-unit-size rating and is capable of a high degree of flexibility. Further developments such as specially prepared and graded media for specific applications, automatic media density control and regulation of media consistency by the use of surface ac- tive agents and polymers have increased versa- tility and sensitivity of control to the point where products differing by as little as 0.02 of a specific gravity unit can now be separated with ease.

Jan 1, 1973

By Rashkovski GB

Until recently amalgamation has been the main process forextracting large gold particles from gravity concentrates obtainedduring the dressing of ores and placer gold deposits.Development of new technology for treating the gravityconcentrates was necessary because of the harmful effect ofmercury on subsequent production processes and theenvironment. The harmful effect of mercury is particularlyevident in the resin-in-pulp process that is widely applied inRussia.

Jan 1, 1993

By S Leary

Diamond drilling since early 2006 has identified an epithermal gold-silver (Au-Ag) deposit beneath 140 m to >400 m of cover. The Fruta del Norte discovery had an inferred resource estimate of 58.9 Mt grading 7.2 g/t Au in October 2007. The mineralisation is hosted by Mid-Late Jurassic andesite and andesite porphyry in a regional fault zone beneath mainly post-mineral but in part syn-mineral Late Jurassic cover. The intermediate sulfidation-style deposit formed before and in part during deposition of epiclastic cover in the fault related pull apart basin. In addition to its size and obvious economic importance, the widespread occurrences of visible gold and exquisitely preserved epithermal textures will make Fruta del Norte an important learning tool for explorationists seeking epithermal mineralisation in theAndes and elsewhere. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

By F Jullian, L Jofre

Many maintenance managers find it difficult to justify investments in maintenance improvement initiatives. In part, this is due to a tendency by mine managers to regard maintenance purely as a cost centre, and not as a process able to influence productive capacity and profit. It is also hindered by a lack of alignment between commonly used maintenance performance measures and key business drivers, and the lack of formal business training amongst maintenance professionals. With this in mind, a model to assist maintenance managers in evaluating the benefits of maintenance improvement projects was recently formulated. The model considers four cost saving dimensions. These are: 1. reduction in the cost of unplanned repairs and maintenance,2. increased or accelerated production and/or sales,3. spares inventory reduction, and4. reduction in over-investment in physical assets and operating costs. This paper discusses the application of this model and a number of numerical examples are given to justify investments in maintenance improvement projects having varying objectives.

Jan 1, 2006

By Robinson WB

An accurate and rapid assessment of coal resources, such as that provided by computer modelling, forms an intergral role in evaluating CSR's coal deposits for future development. An in-house system utilising a number of geological, engineering, costing and financial evaluation routines has been developed for DEC VAX computers. The system is currently being upgraded and enhanced to meet the demands at the various mine sites. Computer modelling of the geology is performed on encoded drillhole information and coal core chemical and physical analyses. A conceptual mine plan is formulated then digitized and superimposed on the geological model. Insitu and product coal reserves and qualities as well as overburden and parting quantities are then calculated for each strip or block. These strip parameters are then transferred to the mine scheduling routines to determine the most efficient mining sequence for the mine plan. Cost factors and scheduling data for equipment specified in the conceptual mine plan are used in the mine costing subsystem. The financial subsystem then evaluates the likely return on investment. Future enhancements to the system include improvements in the response time through the introduction of interactive graphics, the direct interfacing of geophysical and analytical data, and further development of a geotechnical'database.

Jan 1, 1983

By Stewart Gillies AD

Resource rent taxes are taxes which only become effective at such a time as a pre-determined rate of return has been achieved by an operation. Resource Rent Taxes have from time to time been considered for implementation in both Australia and New Zealand. The offshore petroleum industry in Australia is already subject to RRT as is the Roxby Downs (Olympic Dam) Mine in South Australia. Both the mining and petroleum taxation regimes in Papua New Guinea include a resource rent tax component called Additional Profits Tax.

Jan 1, 1995

By Tomlinson R. C

There are two main aspects of coal preparation to which the operational Research Executive of the National Coal Board has applied computer models. The first is in the planning of preparation plants and the first part of this paper discusses Simprep, a computer package that was designed to help on these calculations. The other is the development of control schemes to improve quality control, and the second part of the paper deals with the development of simulation techniques for this purpose.

Jan 1, 1977

Cleaner Production stands for a proactive and preventive approach to industrial environmental management and aims for process- and/or product-integrated solutions that are both ecologically and economically efficient (æeco-efficiencyÆ). Pioneers in the field were large manufacturing and processing industries in the USA (since the late-1970s), but it took until the early-1990s before Cleaner Production was generally recognised as a valuable approach for large and medium sized enterprises. The application of Cleaner Production in mining and minerals, metals and energy production appears to lag behind other sectors, such as manufacturing and processing. This paper starts with a discussion of the Cleaner Production concept and provides examples of its application from a few selected Australian mining and minerals processing industries. This evidences that Cleaner Production can achieve significant reductions in environmental impact, in terms of reduced waste and emission generation and in terms of conservation of materials, energy and water, while simultaneously reducing operating costs. The paper then investigates a number of key issues pertaining to the implementation of Cleaner Production; ie organisation and management of Cleaner Production activities, effective tools for mastering the Cleaner Production concept as a way of life, and performance measurement.

Jan 1, 2002

By Jingmin Xin, Wenhua Xing, Zongxin Huo, Hongzhang Chen

Drawing up the successive plan for mining and development is a very important and regular plan work. The expert system of the successive plan for mining and development drawn up by computer is developed on the basis of network, computer simula

Jan 1, 1998

By Hagan T. N, Tucker A. J

The Cumnock Open Cut Mine (COCM) is located in the Hunter coalfield in New South Wales. Five coal seams are being mined, mostly by drilling and blasting, loaders and excavators, and trucks. The annual production of coal is 1.3 million tonnes. Overburden and interburdens consist mostly of siltstones and medium to thickly bedded sandstones. The strata dip to the south-east at approximately four degrees. There are no major faults in the rock mass.

Jan 1, 1995