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Over a four year period from 1984 to 1987, a broad range of ground conditions were experienced in recovering old workings at the Walhalla mine in central-eastern Victoria. Access to the ore zone was gained via old workings and new development. The work included: Recovery of vertical and inclined shafts. Recovery of collapsed winzes. Recovery of level drives and crosscuts. Spiling through broken ground and old mullock. Pre-grouting of caved zones. New development using small-scale rail equipment and "bobcat" Loaders.

Jan 1, 1988

This paper deals with innovative techniques that have enabled personal computers to be used on the mine site to define, develop and manage an ore body resource, while being aware of the consequences to the environment. The same set of personal computer tools that are used for resource estimation, once the province of expensive workstations, can also be used by geologists, mining engineers, surveyors and environmentalists, in managing the whole mining process, including production, grade control, monthly reconciliation and stockpile management through to tailings the management, mine rehabilitation and the due diligence process of mine closure.

Jan 1, 1996

By K Steamy, D Lesmana, K Yulia

Effective selective mining relies heavily on high quality geological data and assay data. Such assay data is dependent on effective sampling protocols, sample preparation techniques, assaying practices and well founded quality assurance/quality control (QA/QC) procedures. This paper describes recent developments in grade control sampling at PT Nusa Halmahera Minerals high-grade Kencana gold mine at Gosowong Indonesia and presents a case study in identifying, minimising and monitoring random and systematic sampling error including the use of duplicate sampling and the Thompson Howarth technique for quantifying random sampling error.

Jan 1, 2009

Subsurface development requires some geotechnical conditions and challenges. Most of then are related to the compatibility between tunnelling system and surrounded ground conditions, and design criteria. Design criteria usually involve lining pressure and ground control of displacements. In order to fulfil these requirements, geotechnical parameters have to be obtained as well as construction aspects have to be taken into account for predicting the tunnel behaviour. The Brasilia Metro is presented as a case history illustrating the geotechnical conditions and challenges for its implementation. It is 42 km long, including tunnels excavated in collapsible porous soils by the New Austrian Tunnelling Method. The Brasilia porous clay presents some characteristics, which may lead to large deformations due to structural collapse. Empirical methods were calibrated for collapsible porous soils and then applied to predict tunnelling-induced settlements. Settlements due to soil structural collapse modify completely the expected settlement profile, increasing their values from the tunnel crown to the ground surface. Consequently, surface settlement trough volumes were also greater than the ground losses around the tunnel. In this case history, structural collapse of porous soils played an important role and must have been taken into account to predict correctly the settlement trough and profile. Numerical simulation has shown that settlement magnitudes due to structural collapse are strongly dependent on the soil stiffness reduction after collapse and the extent of the collapsible zone.

Jan 1, 1999

The development of reliable and accurate solution sampling systems plus on-line atomic absorption spectrophotometers and voltammetric analysers at Pasminco Metals - EZ's (PMEZ) zinc refinery at Hobart, Tasmania, has led to extensive implementation of On-Stream Analysis (OSA) throughout the hydrometallurgical circuit. These systems complement industrial autotitrator and colorimetric analysers and with the comprehensive use of a powerful integrated Distributed Control System (DCS), provide extensive monitoring and control of all the important in solution' parameters for the plant. Samples can be left unaltered, or filtered or settled, to remove solids. They are then precision diluted and pneumatically transported to analyser shelters, where they are analysed for zinc, acid, copper, cadmium, lead, antimony, cobalt, nickel, mercury and ferrous, ferric and/or total iron. The range of analyses depends on the sample itself. The results are used for feed forward and/or feedback control of reagents where possible, or simple trend monitoring and out-of-specification alarming when closed loop control is not practical. The overall system reliability and accuracy is such that many daily composite plant samples are no longer analysed off-line. Operator sampling has also been reduced, and in two places, autotitrators with automatic sample pre-treatment have been installed for preparing and analysing samples collected by operators.

Jan 1, 1993

By I Brunton

Blast fragmentation can have a significant impact on the profitability of a mine. An optimum run of mine (ROM) size distribution is required to maximise the performance of downstream processes. If this fragmentation size distribution can be modelled and controlled, the operation will have made a significant advancement towards improving its performance. Blast fragmentation modelling is an important step in Mine to MillTM optimisation. It allows the estimation of blast fragmentation distributions for a number of different rock mass, blast geometry, and explosive parameters. These distributions can then be modelled in downstream mining and milling processes to determine the optimum blast design. When a blast hole is detonated rock breakage occurs in two different stress regions û compressive and tensile. In the first region, compressive stress waves form a æcrushed zoneÆ directly adjacent to the blast hole. The second region, termed the æcracked zoneÆ, occurs outside the crush one. The widely used Kuz-Ram model does not recognise these two blast regions. In the Kuz-Ram model the mean fragment size from the blast is approximated and is then used to estimate the remaining size distribution. Experience has shown that this model predicts the coarse end reasonably accurately, but it can significantly underestimate the amount of fines generated. As part of the Australian Mineral Industries Research Association (AMIRA) P483A Mine to MillTM project, the Two-Component Model (TCM) and Crush Zone Model (CZM), developed by the Julius Kruttschnitt Mineral Research Centre (JKMRC), were compared and evaluated to measured ROM fragmentation distributions. An important criteria for this comparison was the variation of model results from measured ROM in the fine to intermediate section (1 mm to 100 mm) of the fragmentation curve. This region of the distribution is important for Mine to MillTM optimisation. The comparison of modelled and Split ROM fragmentation distributions has been conducted in harder ores (UCS greater than 80 MPa). Further work involves modelling softer ores. The comparisons will be continued with future site surveys to increase confidence in the comparison of the CZM and TCM to Split results. Stochastic fragmentation modelling will then be conducted to take into account variation of input parameters. A window of possible fragmentation distributions can be compared to those obtained by Split. Following this work, an improved fragmentation model will be developed in response to these findings.

Jan 1, 2001

With the exeption of the United States, Canada and Russia, oil has not been around in quantity near world centres of population. Production: in Western Europe is insignificant. Japan is without production as are Australia, Southern Africa, India; Brazil, Chile, New Zealand and China. The United States is, however, a large importer of crude oil. The very fact that oil is produced generally away from centres of population means that it has to be carried by sea to the area in which it is required. There is, therefore, a constant flow of oil around the world in very definite channels.

Jan 1, 1962

By Toivanen R-M, Leinonen O, Pekkarinen H

This paper presents developments in designing an integrated mine control system at Kemi mine. The aim of this paper is to present the general structure of the system and to outline some features of the process control strategies. The results o

Jan 1, 1998

Mining regulatory authorities worldwide mandate frequent inspection of winder ropes used in shaft-equipped underground mines and ski lifts. Visual inspections are effective in identifying and assessing the type and severity of damage found in the exterior of the rope. In addition, electromagnetic or permanent magnet-based methods are used to identify broken wires, corrosion damage and other anomalies that occur anywhere within the core of wire ropes made of steel, which is a ferromagnetic material. The magnetic methods yield the loss of metallic area due to wire breaks and other damage in the ropeÆs section as well as local flaws that give rise to discontinuities in the magnetic field. The quantitative measurement of the loss of metallic area is indirectly related to the loss of breaking strength that is commonly used as a rope discard criterion. The ropes used in a mine winder in the Goldfields of Western Australia are inspected using Meraster 120B permanent magnet-based rope tester and their condition is assessed against published discard criteria.

Jan 1, 2003

This paper describes the technique developed by the Australian Coal Industry Research Laboratories (ACIRL) for the treatment of bore core samples to obtain data for coal preparation studies of the target reserves. The particle size distribution within the sample has a significant influence on the relationship between the yield and ash per cent of the floats coal at any ash level. The size analysis within the reconstituted feed from a coal preparation plant is determined by the size analysis of the feed coal, physical degradation of material in the process, and the breakdown of associated shales in water. The extent of material breakdown was studied in the ACIRL coal preparation pilot plants. The method of bore core evaluation includes simulation of this breakdown in a sample selectively crushed to conform with predicted or known run-of-mine size distribution. Modifications have also been made to the laboratory methods for froth flotation to approximate more closely with industrial practice.

Jan 1, 1977

By H E. S Moorcroft, D Scott

The increasing mining depths of South African gold mine deposits are resulting in ever-increasing heat loads associated with depth and the geothermal gradient. Together with changes in the mining horizons brought about by the depletion of older, shallower, high-grade reserves, this leads to the need for the continuous review and redesign of cooling requirements. Traditionally, cooling requirements were met by using a combination of cooling strategies, including bulk air cooling on surface and underground. If this proved to be insufficient, chilled service water and secondary remote air-cooling systems were introduced. This paper reviews these practices in order to provide a cost-effective means of catering for the introduction of hydropower at the Gold Fields Ltd South African operations. Some of the equipment that has been developed to meet the requirements of both hydropower and refrigeration includes hydropower fans, cooling coils and in-stope venturis. These are individually described and discussed, together with their roles within the greater strategy. The planned change in the cooling strategy and the employment of these technologies have effectively doubled the cooling available, from 10 MW to more than 20 MW, extracted from the hydropower water used to drive the mining equipment. In conclusion, the cooling strategy described allows a total heat load of approximately 52 MW to be successfully ventilated and cooled through the use of combined surface and underground refrigeration installations, and through the use of hydropower-chilled water.

Jan 1, 2005

Downstream value-adding is a strategic issue for a country like Australia, which has a resources-driven sector of a scale that has significant impact on the national economy. The question of why producers are not doing more to ævalue-addÆ is often asked. In Australia this debate takes place within the context of: an era of unprecedented growth in demand for resources driven by the rapid urbanisation of China, India and others;impending legislation and uncertainty around carbon pricing;rapidly rising energy costs;significant supply-side shortages including infrastructure, skills and manufacturing capacity; andsignificant industry consolidation of primary resource producers with commensurate improvements in market power.There are several examples of resource-based industries which have developed their business along the complete value-chain; for example large oil and gas producers successfully span upstream and downstream operations including refining and petro-chemicals as well as retail distribution of fuel and other products. Relevant frameworks that provide insight and understanding into the strategic issues around value-adding are reviewed and examples of the application of these frameworks to companies and industries which have successfully adopted a strategy of integrating along the value-chain, as well as those players who have focused on parts of the value-chain are presented. The issues around value-adding in Australia are then reviewed with reference to these frameworks and it is concluded that the issue is a conflict between the objective companies who wish to maximise financial value versus the desire of governments to increase economic benefits. An approach to aligning these objectives is proposed.

Jan 1, 2008

The patented "Epytensic" pump of Minnovation Ltd, a multiple piston pump, is used widely on shearer loaders and by partial high pressure watcr jet cutting strategically in relation to cutter picks not only improves cutting rates, but saves power and increases the life of gearboxes and picks, as well as improving dust suppression. The "Face Side Pump", also a piston pump, located on the ranging arm gearhead has advantages over gateroad pumps and shearer body pumps. The "Extraction Drum", hydraulic air mover system, linked with the above innovations and high pressure water, have further advantages in methane and dust removal. Some modifications providing these systems need workshop applications but most are possible underground with minimal changes to shearer profiles and advantages of minimising hosing, along with the other advantages stated.

Jan 1, 1991

Some of the major factors affecting ore reserve estimation in gold mines are discussed together with their impact on computational methods.The major priority in ore reserve estimation is to get sampling and geological problems resolved. Poor basic information cannot be remedied by mathematical methods.Generally the more complex a deposit becomes the greater the need for subjective assessment and the less applicable are more complex ore reserve methodologies.

Jan 1, 1984

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 Grainger A, Dawkins G, Lysaght A, Kennedy R

Maintenance management improvement projects were undertaken at several BHP Collieries Division mines pursuing.the objective of achieving better structured maintenance procedures. Efficiently structured maintenance and optimum asset use are interdependent and productivity and computer models assist towards that objective. Definition of aspects of maintenance and analysis of the nature of equipment and materials, workloads and tasks, lead to more effective planning and scheduling of maintenance. The quality, standards and procedures of records must be suitable and adequate for storage and future retrieval. Total Quality Control initiatives and improvement projects even extend into spheres of customer/supplier relationships and problem solving teams as well as the more recognisable standards of management and performance factors in maintenance. All such factors contribute to a Maintenance Management Matrix to provide a better structured approach to economic maintenance management in the capital intensive coal mining industry.

Jan 1, 1991

By Bourke J. H, Ashcroft T. B

Many changes have occurred in the world market for manganese over the last five years. Among these, the emergence of divided steel processes for the hot metal refining of pig iron is affecting the use of both ferruginous manganese ore and ferro manganese, at this stage particularly in the Japanese steel industry. Subsequent demand for higher quality manganese materials is promoting the use of thermally beneficiated products such as sinter. In addition, many processes are being developed for the direct smelting of fine manganese ores, of which plasma technology is the most advanced. Cost pressures and product quality requirements are encouraging pre- viously self sufficient countries such as The People's Republic of China and the USSR to import high grade manganese ores to supplement indigenous lower quality supplies. At the same time, Brazil has been provided with the impetus to convert its substantial reserves of ore to value added products.

Jan 1, 1988

By Kuruppu M

Geotechnical design plays a key role in mine design. A proper geotechnical design provides a safe working environment and facilitates efficient mining operation. There are mainly three design approaches: (i) judgmental, based on observational and experiential facts, (ii) empirical, based on empirical design formulae; and (iii) analytical, incorporating numerical analysis. Most design applications are based on the design methods one and two as mentioned earlier. However, complexities arise in deep underground mining operations and deep open pit mines. These complexities and difficult geological environment introduce more uncertainties and simple empirical formulae would not be adequate as a design tool. These situations require numerical modelling and analysis of the design problems including interpretation of the results obtained from the analysis. There are several tools available for performing the numerical modelling and analysis. A brief review of the available tools is provided. The authors selected ANSYS (a general purpose finite element analysis tool) for use in mining geomechanics and geotechnical design. This paper includes several examples demonstrating the applicability of this software in designing mining structures. The authors hope that the design examples will demonstrate the use of the numerical modelling and analysis applications in excavation design.

Jan 1, 1995

A Devonian metallogenic province is extended northwards from central Queen- -sland to the Burdekin Basin in the Charters Towers Gold and Mineral Field. Devonian sediments of the Burdekin Basin are intruded by mineralised quartz felspar porphyry which occurs as pebbles in Upper Devonian conglomerate. A mineralised volcanic complex lies on the crest of an anticline in Devonian sediments.Red siltstone is slurried and reduced to pyritic hornfels over folded limestone.A thick wedge of volcanogenic conglomerate overlain by marine shale lies on the mineralised rim of an ocean which suffered cataclysmic changes during Late Devonian times.

Jan 1, 1987

The basic methods to remove material from underground mines are to: convey continuously, batch in trucks, or batch in a shaft hoisting system. A critical aspect in shaft hoisting is accurately batch loading the conveyance or skip. During the 20th century, the almost universally accepted method of loading was via a measuring flask. A measured quantity of material was filled into the flask as the conveyance traveled through the shaft and then, when the conveyance arrived at the loading position, it was ædumpedÆ into the skip for hoisting. Two skip loading conveyor systems have been developed in Australia: BHP BillitonÆs Cannington Hoisting System, installed in 1996, is believed to be the first conveyor loading system designed for two skips. Two parallel conveyors were installed with a two-way gate controlling feed onto each belt. Cannington was ideally suited to conveyor loading as the very high ore density and relatively low production rate required a relatively small volumetric storage capacity on the weighed belt. Newcrest MiningÆs Telfer Hoisting System, which is to be commissioned in 2005, consists of a single slewing conveyor loading each skip with 32 tonnes of ore. The development of this system eliminates the two-way transfer, improves the accessibility and minimises the excavation required. While every hoisting system must be considered on its merits, conveyor loading offers significant advantages to the Mining Industry in the 21st century.

Jan 1, 2005