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The Myally Beds, Surprise Creek Beds and Mount Isa Group form the upper part of the Proterozoic Western succession of rocks in northwest Queensland. The latter two units are partly equivalent, and are important for their base metal content at Mount Isa and elsewhere. The arenaceous Myally Beds lie unconform- ably or disconformably below the Mount Isa Group and Surprise Creek Beds; they contain four mappable units which were deposited on a broad, shallow shelf washed by east-trending currents. Emergence of the Myally shelf initiated a series of parallel, possibly intra- cratonic, troughs to the east and west. In the east, the Surprise Creek Beds were deposited between the emergent shelf and base- ment rocks, and consist of a shelf and trough facies divisible into 7 and 10 units, respectively. Trough sediments are continuous north-south, and show turbidite character- istics; algal dolomite characterizes the shelf facies. To the west in the Mount Isa trough, an orthoquartzite facies, the Warrina Park Quartzite, defines the base of the Mount Isa Group. Hinge zones between the shelf and trough environments are marked by east-west facies changes, and provide a focus for later major north-south faulting. However, some penecon- temporaneous faulting near Mount Isa is best explained as complex post-depositional faulting of a disconformable sequence. Subsidence and deposition in the Mount Isa trough continued for a longer period than in the Surprise Creek trough, allowing accumulation of lead and zinc deposits in the upper half of the sequence. The Surprise Creek Beds appear equivalent to the lower half of the Mount Isa Group, and are probably not prospective for lead and zinc. Turquoise and possible other secondary copper minerals are widespread in the Warrina Park Quartzite and equivalents in the Surprise Creek Beds, and further investigation of these formations seems warranted.

Jan 1, 1974

When Matthew Flinders entered in his log `This land forms the South side of the large bight; and besides projecting beyond the coast line, and being a little higher than usual is remarkable for having some reddish cliffs in it, and deep water near the shore', he was commenting on the deposit of bauxite at a place now known as Weipa. This sighting took place on 9 November 1802, and probably represents the first direct entry in Australia acknowledging a potential mineral deposit. Flinders, of course, had no idea as to what he was looking at, nor did he land to determine its content. If he had, he probably would have had no idea of the substance, and even less knowledge of its use. Nothing further was done to this for about 150 years.

Jan 1, 1993

By K Thompson

The Diavik Diamond Mine is a world-class operation located in an extreme environment 220 km south of the Arctic Circle in CanadaÆs Northwest Territories. The mine has a number of distinctive characteristics û such as limited winter access via an ice road, mine infrastructure being located on an island, with mining taking place behind dykes holding back a lake, temperatures at the mine that get down to -45¦C in winter, and the presence of bears, wolves, foxes and wolverines! One thing that Diavik does have in common with other mines around the world is the need for reconciliation. In late 2005 Diavik implemented SnowdenÆs Reconcilor software system to facilitate the process of reconciling geological models, mine plans, production data and plant results. This paper provides a case study of the reconciliation system implementation. It outlines the migration of Diavik away from a comprehensive and effective spreadsheet-based reconciliation process to a commercial grade, automated and web-based information management system. This paper documents the reasons for moving away from the spreadsheet system, the key parameters used for reconciliation, and the benefits gained by closing the loop between reconciliation and ongoing process improvement.

Jan 1, 2006

By G McSpadden

At September 2001 the beneficiation plant at BHP Billiton Iron OreÆs Mt Whaleback mine is set to treat 9.5 million tonnes per annum (Mtpa) of iron ore, 40 per cent better than original design. This paper describes the steps, decision-making processes and innovations used to increase capacity at minimum cost. The plant was designed in 1979 to operate at 1133 t/h for 6000 hours per annum, treating 6.8 Mtpa. Sufficient suitable contact ore was unavailable and feed was finer than planned. The plant was designed with minimum surge capacity between multiple process units. It had never reached design capacity. In 1993 a study by Fluor Daniel to treat increased tonnage resulted in modifications to improve plant operations. Efforts to expand production by increasing reliability did not achieve the desired capacity. NJ Morrow (Pty) Ltd (NJM) conducted a technical audit in 1996 with process evaluation by Mineral Processors. Replacement of operator interface and PLC logic in 1997 made plant operation and diagnosis easier. Involving operators in logic development enhanced their plant knowledge. Fluor Daniel Simulation developed a simulation model of the process. Mineral Processors and NJM reviewed the model findings, recommended metallurgical improvements and developed preliminary designs and costs. BHP Engineering produced a detailed design with a cost estimate of $A34 million. After analysis and revision of the design, a $A10.4 million upgrade to 8.5 Mtpa was carried out. Detailed modifications to the process units, particularly the HM drum plant, allowed significantly higher capacities and improved metallurgical performance. The target capacity was achieved in June 2001. Further modifications are progressing to treat lower-grade ores.

Jan 1, 2002

In South African gold mines, the types of material requiring transportation to the stoping areas include timber packs, explosives, hydraulic rock props, scrapers, scraper winches, pipes, pumps and backfill material (in areas where backfill is being used). Currently timber packs are broken down to their basic components (log and brick) and are transported into the stope by means of either monowinches or a combination of monowinch and scraper winch. Other materials, such as explosives, hydraulic rock props, scrapers, scraper winches, pipes, pumps and backfill material must be transported by other means, usually by hand or, in the case of heavier items, by chain blocks. With the drive to increase stope advance rates and the rise in the number of miners with HIV/AIDS, there is a need in the South African gold mining industry for an improved material handling system. To meet future requirements, material handling systems should assist miners to transport materials quickly and efficiently. Furthermore, it must be financially viable and economically competitive with current material handling systems. This paper looks at the in-stope material handling efficiency of current monowinch systems and provides solutions to improve efficiency. In addition, the use of in-stope monorails are reviewed and the possible scenarios that will substantiate the use of monorail systems are discussed.

Jan 1, 2003

A paper describing the treatment of the Mary Kathleen uranium ores must necessarily be historical and confined mainly to a review of the four papers which have already appeared. Couche and Hartley (1958) described the development of the treatment process just prior to the commencement of operations in June, 1958. Harris, Boag and Hemingway (1961) described the treatment during the operations, and Wreford (1965) reviewed all aspects of the mine and mill, when operations were suspended in November, 1963. Harris and Steele ('1960 presented a paper especially describing the radiometric sorting operation. Some hitherto unpublished information is also presented in the paper to describe some of the peculiarities of the ore, indicate reasons for the adoption of the treatment flowsheet, and some interesting problems connected with this treatment.

Jan 1, 1968

By C Hertle

GHD-Black & Veatch (GHD-BV) have completed design and specification of the ash thickening plant at Tarong Power Station, including operation of a pilot plant. Construction of the plant is in progress and commissioning is planned for early-2004. The objective of the new plant is to convert the low concentration (lean phase) ash slurry currently generated by the power station into concentrated slurry which will then be pumped to the existing ash dam. Water recovered from the lean slurry will be returned to the power station for reuse. The drivers behind this project are to extend the life of the ash dam and to reduce water pumping costs. A maximum flow of 1000 litres per second is expected in the thickening plant. The process involves a screening phase, which removes large material that could cause blockages or equipment damage. A 50 metre diameter thickener then concentrates the screened lean ash slurry to 55 - 60 per cent w/w solids. In addition, the thickener plant will allow the harvesting of floating cenospheres (hollow, spherical ash particles) from the lean slurry. Cenospheres are currently collected from the surface of the ash dam and drained on a pad adjacent to the dam. The new system will use a surface skimmer to remove the cenospheres from the thickener and transfer them to settling ponds for further classification. The settling ponds simulate the detention on the existing ash dam, and allow entrained fine ash and slow settling cenospheres time to settle. As settling occurs in ponds, the slow settling cenospheres can be completely recovered whereas when they settle in the dam, the opportunity for recovery is lost. Cenospheres are a valuable by-product produced during the combustion process, and recycling of this material reduces the waste generated by the power station. Water recovered from the thickener drains to a three megalitre reservoir. Water is drawn from the reservoir for thickener plant service water and various other uses in the power station. The bulk of the water is used to sluice ash from the power station to the thickening plant. In the current configuration, surface water from the ash dam is reused but must be pumped several kilometres back up to the power station. The dam also holds an inventory of several thousand megalitres of water and has significant evaporative losses. Therefore the current raw water make up demand is substantial. In addition, some areas of the power station traditionally using raw water will be modified as part of this project to allow the use of recovered water, further reducing the raw water demand. The design incorporates many features of sustainable water management. By more effectively recovering water from the lean ash slurry, the amount of raw water make up required by the system will be significantly reduced. This method of water recovery provides a more sustainable and energy efficient ash-transport mechanism.

Jan 1, 2003

By Walraven F, Knott G. G

Using a typical small logging instrument (Neltronic KPD), a natural gamma reference section for part of the Brockman Iron Formation and part of the Mt. McRae Shale has been established in the Newman area. This is compared with the stratigraphic type section of Trendall and Blockley (1968). Folding and faulting are recognised using natural gamma logs. Because of the confidence with which stratigraphic horizons can be identified, less expenditure on diamond and percussion drilling is required to confirm stratigraphic position. Using natural gamma logs as stratigraphic control the apparent thinning of the Banded Iron Formation during iron enrichment is Demonstrated.

Jan 1, 1973

By P Jago

KCGMÆs Fimiston Open Pit, located in the centre of the historic Golden Mile, is situated above some 3000 kilometres of old underground workings. These workings, both level and vertical, present significant safety and operational problems in the pit. One of these challenges is in safely drilling void areas so that they can be charged and blasted effectively. Current drilling practices in these areas require machines that can only drill 115 mm holes on a smaller pattern than the standard blast pattern. This results in more time and cost to both drill and charge these areas. Any other method currently available to drill out these areas involves putting operators in a potentially hazardous situation by being too close to the void area being drilled. Not effectively drilling and blasting these areas leads to hazardous situations further in the mining cycle including oversize, large toe and uncollapsed voids. Ineffective blasting also causes reductions in mining productivity and mine to mill performance. In response to these issues, KCGM has commissioned the implementation of a fully remote controlled DM45 blast hole drill rig to drill out selected void areas. The remote system, installed in conjunction with Ausdrill Ltd and GM Mining Electrics, is designed to operate similarly to a tele-remote bogging system with the operator controlling the drill rig from a separate control cabin via radio signals and video feed. This allows KCGM to drill in areas of higher risk without exposing the operators to voids. The drill rig will also be able to drill standard patterns through some specially selected void areas, reducing costs and extra time associated with drilling and charging void affected areas. The remote rig is expected to provide a number of benefits, both in the drilling process and in further downstream operations. Costs of drilling in void areas are expected to decrease with standard patterns instead of smaller patterns being drilled. Safety and operator comfort are also expected to increase through removing the operator from the pit floor. Blasting is also expected to see significant improvements through increased ease of charging void areas (because of larger holes and standard patterns), more consistent patterns resulting in less secondary blasting and toe and an overall improvement in the speed and cost of charge-up practices. This more consistent blasting will also improve shovel productivity, crusher performance and overall mine-to-mill efficiency. This paper presents an overview of the development of the remote controlled system, including modifications that have occurred since commissioning. It explains some of the problems encountered and how these have been solved. Key issues for operational success will be identified and explained with a view to making future implementations easier. Factors used to assess the performance of the remote controlled rig will also be explained in further detail and used in a preliminary assessment of the rigÆs feasibility.

Jan 1, 2003

By Walker BV

Mining activity has been an integral component in the New Zealand economy since the early days of European settlement. Recently in common with other Pacific Rim countries there has been a resurgence of investment in gold. A sustained and increasing exploration effort has resulted in the rapid development of alluvial gold mining operations, a number of hard rock gold discoveries, and a general optimism about New Zealand's prospectivity. New Zealand's attitude to mining development, in particular hard rock gold mining is influenced by high environmental values and a concern, largely through absence of examples, that modern mining may not perform to community standards. While these environmental concerns are wide spread there is a growing realisation that gold mining, if properly managed, can take place within acceptable environmental standards and that it has the potential to contribute significantly to New Zealand's economy. New mining developments have an important role to play in this process. The mining industry in New Zealand is now at a crossroads. Having invested substantially and confirmed the potential for gold mining developments it has found itself in a rapidly changing economic environment as the Labour Government puts in place a number of fundamental economic reforms. The reforms are intended to free up the economy removing the rafts of subsidies and protective measures which have stultified initiative and growth. A fundamental reform of the public service has been initiated including corporatisation of trading activities and the establishment of a Department of Conservation to administer estensive areas of Crown land. Both petroleum and mining taxation are being reviewed with the intention of creating a more neutral competitive environment. Mining legislation is also being re-examined with both efficiency and equity objectives. While the current environment is characterised by uncertainty and rapid change, the outcome will be a more market-oriented stable policy environment, to the mutual benefit of the industry itself and the New Zealand Community.

Jan 1, 1987

By Coulter K. W

The commercial evaluation of coking coal from bore core data will begin with a technical evaluation of the coal properties affecting coke quality. Methods currently used for prediction of coke.properties from coal analysis are illustrated but in each case accuracy of measurement and prediction should be clearly understood. It is suggested that coal be initially valued from coking properties (base value) and adjusted for chemical properties (merit value). Final evaluation of coal can only take place as coke in the blast furnace where the coke is assessed under high temperature operating conditions. The commercial value of a particular coking coal will depend on many additional factors other than the technical properties.

Jan 1, 1977

The accurate calculation of ore reserves is one of the most important functions under- taken at a potential or operating mine. In recent years there has been a trend towards recommending more and more complex techniques for the calculation of reserves. However these are not always necessary and many improvements could be made by the use of all potential data and a heavier geological input. An ore reserve should be the result of geological not mathe- matical or engineering reasoning. All ore reserve estimates are wrong and the important thing is to.recognise why they-are wrong and to take action to minimize the errors. Geostatistics and other complex mathematical techniques may appear to answer all our needs for ore reserve accuracy but there are many drawbacks, not least of which is the communi- cation gap which may develop between the operator and both management and production Personnel.

Jan 1, 1979

By Jeffrey IC

This paper presents a method of measuring field power consumption of shearers and deriving specific energy consumption versus shearer haulage speed performance curves. A description of a computer program which simulates the cutting action of a shearer drum is presented. A comparison between the field specific energy curves and the computer simulation results is made. The simulation results compare well with the field data where all the coal seam is being cut by the shearer. The computer simulation results give back-calculated field pick force cutting characteristics, which allow the performance of the shearer to be predicted for other operating conditions, e.g. effect of changes to pick lacing, effect of changing the drum rotational speed, allows the calculation of power requirements for a particular production rate.

Jan 1, 1992

The paper first outlines the conceptual basis for evaluating and controlling geological risk. Geological risk, the economic reflection of the uncertainties associated with tonnage, grade, and other pertinent deposit parameters, is evaluated in terms of economic risk criteria. Delineation provides the deposit information required to appraise and control this risk. The improved reliability of geological estimates resulting from additional delineation reduces the economic risk associated with mine development and production decisions. However, the benefits of delineation, subject to diminishing returns, have to be weighed up against the direct and time costs involved. These costs decrease base case economic values and shift the probability distributions of possible outcomes towards, lower values. The optimum amount of delineation normally is achieved short of the point where economic risk is minimised, depending on the mining company's relative preference for a higher base case value or a lower economic risk. Then, two open pit copper mine examples, based on actual situations, are analysed to illustrate the application of the concepts presented. The first case concerns the extension of ore reserves at an operating mine. Finally, a new mine development opportunity is considered.

Jan 1, 1994

By F Mwijage

"The benefits of measuring blast movement to reduce ore loss and dilution have been recognised by many people for many years and various methods have been used with limited success. Geita Gold Mine is running the pilot study on the blast movement monitoring (BMM) system which is a revolutionary method developed and patented by the University of Queensland and Blast Movement Technology (BMT). The system consists of directional transmitters placed within the shot prior to blasting, which are then located after the blast with a special detector and then the data is processed with purpose-designed software.As part of continuous improvement on grade control, Geita Gold Mine is running a research project in all operating pits with the objective of: quantifying the three-dimensional blast muck pile movement and finally utilise the movement data to define post-blast ore polygons and incorporate the movement dynamics during block modelling,quantify the potential savings for ore loss and dilution,improve mine geologists knowledge of blast dynamics, andstimulate greater co-operation between drill and blast engineers and geologists to achieve optimum blast designs.To any operation with selective mining, it is critical to the economics of an operation to control ore loss and dilution; getting it wrong will result in significant lost revenue. Implementation of ongoing pilot study on electronic balls as determinant on blast movement dynamics on ore would be of longer term solution and big investment pay back.CITATION:Mwijage, F, 2012. Pilot study on blast movement monitoring at Geita gold mine, in Proceedings Narrow Vein Mining 2012 , pp 49-58 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 26, 2012

By J Walasiak

In the climate planning of mines and tunnelling with anticipated poor climatic conditions, and especially in case of longer working shifts, the main question is whether it can be reliably prevented that certain climatic limits laid down be exceeded. Working at high temperature and/or humidity can lead to reduced human working energy û a very important economic aspect û and to a risky lack of concentration on the part of the miners or to heat collapse and extremely dangerous heat stroke. With the Deutsche Montan Technologie GmbH (DMT) climate prediction programs, both the dry and the extremely significant humid heat transfer can be calculated. This is due to the high planning reliability involved. With the help of these climate prediction programs it is already possible to determine the anticipated climatic values for the operation phase as early as the planning stage of new ore or coal fields or of tunnel construction projects and to design the optimum air cooling system for every underground project with due regard to technical and economic aspects.

Jan 1, 2005

By Tilley J. L, Chicu D

The development of the Yallourn East Field brown coal open cut has involved the adoption of novel investigational programs into coal qual- ity. For example, weighted average coal property statistics for key proper- ties are determined by using a unique blend of traditional and 3-dimensional geostatistical estimation. Predicted property values are made freely available from the mainframe computer in the form of kriged esti- mates of 60 000 tonne coal blocks. Geostatistical predictions are being incorporated within the Mincom/Intergraph CADD system which is used for mine design. Key properties relating to coal type, moisture, and ash have been evalu- ated to provide the required data for the design and operation of both the open cut and the power stations as well as the briquette plant.

Jan 1, 1989

By M Miller

Operators of nickel laterite pressure acid leach and gold pressure oxidation technology frequently employ a series of steam condensing heaters to preheat the leach feed slurry. The heaters are an economic pinch point û although the thermal performance of the heaters is critical to overall process viability and operating cost minimisation, they are also a significant capital item and must be sized accordingly. Despite this, discussions of the factors underlying heater design are conspicuously absent from technical literature, and existing operations feature a conflicting range of heater sizes and configurations. This variety would suggest that at least some of the chosen heater designs are oversized. As part of its detailed design stage, the Ravensthorpe Nickel Project (RNP) constructed and tested a pilot plant heater to develop an understanding of the heating process and to ensure that the RNP heaters were appropriately sized. This testwork used RNP slurry at design density and viscosity on a 450 mm diameter, 6500 mm high column. The pilot plant testwork demonstrated the intrinsic efficiency of the direct steam condensation heating process, which was essentially independent of slurry density and viscosity. Presence of non-condensable gases in the steam phase decreased the heat transferred in certain circumstances, but heater performance remained consistent with thermodynamic limitations. Stagewise heat transfer within the column was rapid, and suggested either a very high slurry surface area or excellent heat transfer within the slurry phase. While the testwork did not set out to distinguish between these effects, physical evidence pointed to droplet formation in the inter-tray shower zone, giving a high heat transfer area. For scale-up purposes, the key facts were that the heat transfer rate was not limited by using high viscosity slurries and heaters could be designed using the principles applied to the smaller of those in existing operations. This paper discusses existing slurry heater designs, the current understanding from open literature, the pilot plant testwork, results and analysis, and scale-up to commercial sized equipment.

Jan 1, 2005

This paper describes the application of the Total Productive Management (TPM) technique as a performance improvement initiative for a coal mining operation. It discusses the objectives of TPM, with the driver for improved production performance being the Overall Equipment Effectiveness (OEE) of the equipment or process, and with the development of "ownership" as the behavioral approach to equipment management and continuous improvement through cross-functional and area-based teams. It illustrates the concept of equipment management as defects management.The scope for application of TPM to the coal mining industry is immense. The harshness of the operating environment can be a major generator of equipment defects, and a current paradigm in the industry accepts these defects as an unavoidable outcome defining maintenance costs in this environment. However recent benchmarking studies have highlighted that maintenance costs per operating hour in some mining operations are more than double the vendor's estimate of "best practice". The paper refers to these studies which also compare maintenance costs of fixed and mobile plant and equipment to "best practice" outcomes in comparable process industries.

Jan 1, 1998

By A Logan, B Cuthbert

Brown and Chitombo (2007) indicated that during the last two decades, the international mining industry has been using mainly mass mining methods to extract safely and economically some of the important commodities such as copper, diamonds, gold, iron and nickel. Mass mining may be implemented either on the surface through large open pits or underground using mining methods such as sublevel, block and panel caving. Developments in the last ten years have demonstrated that caving methods can be applied successfully in strong orebodies at greater depths and in increasingly challenging geotechnical environments for which more traditional mining methods would be unsuitable, unsafe and/or uneconomic. These underground mass mining challenges require æfront endÆ investigation and analysis, robust engineering design and disciplined implementation and operation. Newcrest Mining Limited has focused its efforts on the development of gold/copper projects of substantial scale and margin. To help achieve this, the company is applying and further developing mass mining methods. These include large-scale open pits (OP) and underground mining methods such as sublevel (SLC), block (BC) and panel caving (PC). Block and panel caving now offer economies of scale opportunities for Newcrest to achieve high production rates at lower production costs; thus enabling the exploitation of mineral endowments at higher margins. This paper discusses the practical aspects of caving technologies that Newcrest continues to develop through its expertise at Telfer and Ridgeway SLC operations, Ridgeway Deeps BC and Cadia East PC projects.

Jan 1, 2008