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Grade control aims to deliver quality tonnes to the mill via accurate definition of ore and waste. It comprises data collection and interpretation; local reserve estimation; supervision of development and mining; and stockpile management. The foundation of all grade control programs should be that of high quality sampling supported by geology. The requirement for quality grade control samples has long been recognised, where they should be representative, unbiased, safe and operationally timely. Underground sampling methods include chip and channel samples; grab samples; and drill-based samples. To achieve quality samples, collection techniques employed should minimise delimitation, extraction and preparation errors. Grade control staff should be well-trained and motivated, and mining staff should understand the need for grade control. This paper reviews grade control sampling methods and presents recommendations for best practice and minimisation of sampling errors.

Mar 1, 2010

In underground ore mining of copper ore, lead-zinc ore, tin ore and fluorspare in German Democratic Republic geological situation is characterized by ore deposits of small thickness and great variability of ore grades and mining conditions. For long range mining strategy and short-term planning of production a model was developed fitting to make optimal economic mining decisions. Starting point of the model is a cost function representing all direct costs per unit recoverable metal in concentrate for each stoping unit (ore reserve block). In the costs function the results of regression analysis of ore grade and metal recovery in concentration plant were considered. All stoping units (ore reserve blocks) of a mine were arranged to growing direct costs. The relationships of recoverable metal, ore tonnages and corresponding costs were plotted in a diagram. The data processed by- computer and the graphic representation of the results make possible 1. economic evaluation of stopes and ore reserve blocks, 2. estimation of cut off grade, 3. optimization of works planning.

Jan 1, 1977

By Goldstone A

The paper introduces a newly developed multi-function test rig for fracture grouting. This test rig has many functions and its performance is consistent. It can control and adjust accurately the opening degree of fissures and static pres- sure; it can measure automatically the quantity of grout injected; it can measure precisely pressure drop of grout in fissures; it can test the results of injection, including effective dispersed distance, anti-filtration capacity of consolidated body, mechanical strength, etc. It can inject a single or two grouts into one or several fissures at a pressure of 16 MPa. Therefore, it is an ideal test rig for fracture injection. The paper depicts all the components of the test rig, its performance and application of the results obtained from fracture grouting tests. Examples are briefly described.

Jan 1, 1988

By Tyson G. R

A novel system has been developed using computer imaging techniques to make on-line measurements of material on a moving conveyor. Meas- urements of the mass or volume of conveyor materials are important in large open pit mining operations such as those operated by the State Elec- tricity Commission of Victoria (SECV). Such on-line measurements can be used for monitoring and controlling the production and transport of coal or overburden, and to assist in maintaining production levels. This paper describes a conveyor burden volume measurement system which is currently under development at the Research and Development Department of the SECV and although targeted initially for use in the Commission's open cut mines, the system is suitable for use on any open conveyor system. A basic developmental system has been built to demon- strate the viability of the technique used and further work on the system is planned. The measurement technique and the major components which have been developed as part of the system are described, some comparisons are drawn with other existing measurement systems and potential errors and future development are discussed.

Jan 1, 1989

Comalco Limited has recently completed construction of a $50 million kaolin plant at the site of its bauxite mining and industrial minerals operation at Weipa. The plant will produce 100,000 tonnes per annum of coating grade kaolin for the paper industry. Comalco produced the first coating kaolin from the deposit in 1979 on a trial basis. Since then a variety of quality coating grades with specific particle size distributions and brightness values have been prepared. Extensive drilling and bulk sampling of the deposit over eight years has shown that the ore body is large and of a high grade suitable for the production of premium quality coating kaolins. The processing plant technology was developed by Comalco in association with the European kaolin and equipment producer Amberger Kaolinwerke GmbH (AKW). The Weipa kaolin plant is the first of this size to be built in the Pacific Basin region and it will offer the region's paper-coating mills a stable and reliable source of high-quality kaolin, shipped from an established bulk loading port. The paper provides an overview of the development of the kaolin investment the nature of the production process and details the

Jan 1, 1986

This paper details a proposal for integrating the use of the Pilbara Iron Ore Classification (PIOC) and stratigraphic data for fine tuning blast. pattern design on Mt Whaleback. The main thrust of the proposal is based on the assertion from Haqan and Harries (1979) that rock properties influence blasting results more than explosive properties. This premise is supported by a literature search, which indicated that blasthole burden, spacing, stemming and subdepth lengths are also determined by rock properties if the same explosive and blasthole diameters are used. A brief explanation of the PIOC is provided during which it is noted that the classification is based on physical hardness, mineralogical and genetic characteristics of the ore. The classification also extends to the two main waste rock types LBIF (banded iron-formation) and shale]. Ore type plans produced from face mapping indicate that many areas on Mt Whaleback can be divided into various PIOC zones and regions thus making it more useful in blast pattern design. Several recommendations for blast pattern design experimentation are made for hard, medium and soft ores as well as for the waste rocks, the most important being the use of expanded patterns to blast. soft BIF and medium hard to soft shales.

Jan 1, 1986

By Susanto A

As part of the current NERDDC funded project studying Dragline/Hopper/ Crusher/Conveyor systems for overburden removal, an investigation was carried out to assess the feasibility of automating the swing-to-dump phase of the dragline digging cycle in order to main- tain consistent performance of spotting the bucket above the hopper prior to dumping. The study involved design of automatic position controls for the hoist, drag and swing drives and simulation of detailed mathe- matical models of the three electromechanical systems and their associated electrical control schemes. The design of the hoist and drag systems to position the bucket in the boom plane is relatively straightforward. Simulation results show fast and accurate performance, with no evidence of interaction between the two drive systems through the ropes. The design of the swing position control system involves special strate- gies to cater for variable inertia and to damp the pendulum oscillations of the bucket. The use of a bucket pendulum model and variable dynamic compensation embedded within the feedback control loop, along with optimal speed/angle slowdown trajectories, has yielded fast and damped positioning responses under simulation.

Jan 1, 1989

The methods used by the Anglo American Corporation for analysis of long-term metal markets and prices are described. The principal factors affecting the relationships between production costs and metal prices are analysed. These are firstly the type of market, - speculative or consumer commodity, free market or subject to price control; and secondly the rate of growth of demand for the metal. It is shown that virtually all metals will have relatively low rates of demand growth for the foreseeable future, due to market saturation, increased economisation, substitution and product obsolescence. Metal prices have a clear dependance on production costs, however forecasting future costs is by no means simple; amongst other things, account must be taken of changing exchange rates, inflation rates, and the potential for operating more efficiently. The paper concludes by giving brief assessments of the long-term future for aluminium, copper, zinc, nickel and tin.

Jan 1, 1986

Rock bolting has become the most important method of ground support at Mount Isa. Various types of rock bolts are used to suit the different applications and requirements. To apply rock bolting techniques satisfactorily, it is necessary to have some knowledge of the nature of the rock, the type of rock failure, any stress redistribution which may occur during the intended life of the rock bolt and the time for which ground support is required. At Mount Isa there are a number of dif- ferent applications of rock bolts for ground support, and some trends in rock bolting techniques.

Jan 1, 1971

By B Delaney

For worker safety, mining companies are required to stop production and inspect hoist ropes. Visual inspection is generally done daily and EM inspection occurs every three to four months. During visual inspection, rope speed is generally reduced so an inspector can look for problems. In EM testing the LMA and LF traces are printed on a paper strip chart and a skilled operator interprets these traces. Mining companies only find large defects during visual inspection and are sometimes concerned about the content of EM trace information. This paper will present research outcomes that show how muck can be hoisted while performing a complete visual rope inspection at full speed. Other research results will show that digital signal processing can increase the amount of information available to the EM rope inspector. The research was funded by Inco, C-CORE, three AMIRA International sponsors and six sponsors from the Canadian Deep Mining Research Consortium (DMRC). The research will be commercialised in 2005.

Jan 1, 2005

By Glastonbury J. R

Commercial operation of the Sherritt Gordon process in Australia for the leaching of nickel sulphides has promoted an investi- gation of the factors which influence extraction kinetics. This portion of the investigation has been directed towards the physical and chemical nature of the concentrate and the physical evi- dence of the mode of extraction. Details of the particle size distribution, mineral composition and chemical composition are given. The dis- tribution of various minerals in different size fractions and magnetic fractions is discussed. An electron microprobe was used to determine the composition of individual grains in the concentrate. The solid residue from an ammonia oxi- dation leach was subjected to microphotograph- ic examination, X-ray diffraction analysis and scanning by an electron microprobe. Clear evidence was obtained for a shrinking core mode of kinetic extraction with an amorphous iron oxide product layer contrary to previous reports that the latter is pseudomorphic with the original mineral.

Jan 1, 1973

By A J. Moore

To control the airblast from blasting to regulatory limits at environmentally sensitive sites near the Collinsville Coal Mining Operations, it has been necessary for Thiess Mining to incorporate a wavefront reinforcement analysis model in the predictive environmental airblast design. Controlling airblast from cast blasting 70 m high faces with 2000-3000 kg of explosives per hole within 700 m of houses presents a considerable challenge to the blasting personnel. This paper describes the model used and summarises the results of an investigation designed to quantify the increase in airblast indicated by wavefront reinforcement diagrams to further calibrate the model for future prediction.

Jan 1, 2004

The firing of mass blasts at Isa Mine is a normal operating practice. Both electric and non-electric initiating systems are being used for this purpose. The advantages gained by large firings relate to the Planning, Scheduling, Services and Production functions of Isa Mine. More efficient us"e is made of manpower due to the concentrated charging effort and con- tinuity of the charging operation. In addition, the requirement for ring firing personnel to work at the edge of large stope voids is reduced. Better fragmentation results from the interaction of adjacent detonating rings of blastholes and in flight collisions. With mass blasts there is also less chance of large blocks of ore, created by faults or joints, falling into the stope and creating problems at the drawpoints. The formation of a large tonnage of broken ore facilitates production at scheduled rates from that stope source. The weight of explosive detonating during a mass blast can be considerable. Isa Mine has achieved satisfactory blasting results without excessive ground vibration levels and present knowledge indicates that pillar ground stab- ility has been maintained.

Jan 1, 1978

By Saint-Smith J. C

The anode, tank house and wire bar plant and operations are described with particular reference to those features of design and methods which are characteristic of this refinery at its inception.Reference is also made to auxiliary equipment, transport and materials handling facilities.The work of commissioning the plant late in 1959 is discussed and comment is made on the organisation of construction and origin of the equipment.LOCATION OF PLANTThe site chosen for the copper refinery is on level ground adjacent to the junction of the Mount Isa and the main north-south railway lines at Stuart near Townsville, Queensland. Blister for refining is received by rail from Mount Isa. Refined products are taken 10 miles by road to Townsville Harbour for shipment to other Australian ports or overseas, or despatched by rail direct from the plant.Adequate room for expansion was provided to cover copper refining and any associated industry. The layout of future extensions was planned and space reserved for them before detailing the original units of the main refinery.The initial plant also provides convenient storage facilities and is laid out to derive the greatest benefit from prevailing northerly breezes during the humid tropical summer.As far as possible, the working areas are located so that the prevailing winds cool them as they traverse the buildings.These factors are of very great importance since this is believed to be the only copper refinery in the tropics operating with all white labour and in any case the Company set out to provide the best possible conditions for its operating personnel.

Jan 1, 1961

Feasibility is a value improvement process for projects. At any stage in project development, a feasibility study can be undertaken, but although the scope generally remains unchanged the extent of detail and level of accuracy usually increases with time. The main scope elements are a business definition, project description and an execution plan. The studies are designed to assess the potential of the project and to secure funding for on-going examination. Invariably, the investigations loop back to earlier stages to establish more appropriate development criteria but a critical stage is reached when a project construction decision is requested. This feasibility study requires very detailed presentation and analysis to a higher accuracy for the owner(s) and their potential lender(s).

Jan 1, 1997

Mineral Sands - "An Industry for the Future"The mineral sands industry is matched only by the gold industry in relation to its current buoyancy. The strong demand for the various mineral sands products, creates a positive environment in which to review the technical and commercial factors affecting the future of this industry. This conference is clearly being held in the right place at the right time.My role today is to put forward a few ideas that may help Australia to assert its rightful role as a major downstream player in an industry which it has dominated for 25 years as a raw material supplier.

Jan 1, 1986

By Paley N, Cameron A, Townson P

Although blasthole deviation is a problem which can seriously affect blasting operations, there is little practical emphasis on controlling this deviation and no practical emphasis on understanding its practical behaviour. The most common way of dealing with it involves tight control over drill set up and surveying hole paths. The surveying might involve simple collar location and inclination measurement to estimate the hole's actual path. At best, some operations routinely survey hole paths after all holes in a stope have been drilled. In addition, although there is an expectation that holes will deviate, there is no planning for this behaviour in order to reduce its impact on the blast. Design decisions are invariably made with the assumption that holes are straight. If and when surveys reveal problems it is possible only to adjust charging and initiation to 'work around them'. In extreme cases the drill might be recalled to fill in gaps. The lack of planning and the lack of understanding are doubtlessly linked.A model is presented that will predict the expected path of a drill hole. By knowing how a selected few holes deviated it is possible to make a good estimate of the deviation of other holes in the same rock mass. After minimal calibration the model can be used to increase the amount of information for a given amount of surveying or the amount of surveying can be reduced while maintaining the same level of knowledge of blasthole deviation. Equally important is the ability to plan for the deviation in future drilling through altering the initial collar angles or drilling from different locations. It is the authors' hope that planning for hole deviation becomes as much a part of the design process as planning for detonator delay scatter and explosive performance variation.

Jan 1, 1992

THE power requirements of the Mount Lyell Mining and Railway Company at Queenstown, Tasmania, have, since the inception of smelting operations in June, 1,,896, been derived continuously from the extensive forests in the watershed of the Queen River, adjacent to -the works, the firewood being of good quality, mainly composed of myrtle or beech (Fagus Ounninghami), eucalypts, and manuka (Leptospermum ericoides).The country is very rugged and mountainous, indented by numerous ravines and gullies, and intersected by many creeks, which are subject to periodical floods, under the influence of a heavy and persistent rainfall. The areas so far exploited aggregate a total of about 42 sq. 'miles, and this denuded country gives promise of ultimately becoming very valuable pastoral ground for cattle-raising. The tonnage of wood yielded per acre varies from 40 to 100 tons on stack measurement of 80 cub. ft. per ton, 60 tons per acre being considered a good average yield. The gross amount of firewood handled during the past 13 years approximates 1,200,000 tons, the greater portion of which has been obtained by ordinary tramming methods. The company's main line of railway, 3-ft. 6-in. gauge, has served as a trunk line for all supplies derived from the Queen River valley, south of the reduction works, while the northern and western areas have been exploited by means of...

Jan 1, 1911

By Golosinski T. S, Jorgenson J. D

Several methods are available for inspections of mine shafts. These involve use of inclinometers, moving beams, inertial platforms and decelerometers. Inspections which use decelerometers are of most interest since they allow assessment of conditions of shaft steelwork, conveyances and the shaft itself. This assessment is based on recording and analysing dynamic behaviour of shaft conveyances. Sample inspections of several WA shafts confirm feasibility of using this method for periodic shaft Inspections.

Jan 1, 1995

The Beruang Copper-Gold Deposit is located very near the centre of Kalimantan in Indonesia. It is a dacitic tuff hosted deposit currently being explored by Kalimantan Gold Inc of Canada. Exploration activity to date at Beruang has been focused on the Main Zone, which is defined by a north-south elongate, 1 + 1.5 km zone of anomalous copper and gold, and intense phyllic alteration. The disseminated sulfides responsible for the anomalous copper values produce a moderate to high chargeability signature. Phyllic alteration is overlain at high levels, and on the western edge of the Main Zone, by advanced argillic alteration. The dacite tuffs hosting the mineralisation are cut by post-mineralisation dacite dykes that are delineated by ground magnetics and geological mapping. Base metals, principally zinc and lead, form broad halos around the Main Zone. These metals are incorporated in massive NE-trending, polymetallic mineralisation that outcrops to the north and south of the Main Zone. IP survey results highlight the highly pyritic NNE-trending shear zone, which hosts most of the copper mineralisation in the Main Zone. A high chargeability anomaly at depth in the central-east part of the Main Zone is interpreted to be the source for mineralising hydrothermal fluids. This is suggested by zonations in alteration and mineralisation. A deep chargeability anomaly can be correlated with the downward plunge of a pyritic breccia, encountered at shallow levels in drillholes, and is a potential breccia pipe target. Compilation and inversion modelling of the IP results has yielded some interesting drill targets.

Jan 1, 2004