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The proximity of the Town of Kalgoorlie to the Mount Charlotte mine necessitates that charge weight per delay be limited in order to keep surface vibration levels within acceptable limits and to reduce damage to underground workings. The mining system requires that large mass blasts must be used to recover pillars and therefore a large number of separate delays are needed. Until recently all blasting has been done electrically, fired from mains, but with the introduction of large diameter blastholes (165mm diameter) this firing system was inadequate. Various firing systems were considered, but after extensive trials a non-electric sequential firing system was chosen. This system fulfilled all criteria of blast design, was relatively straight forward in charging technique and had a very simple primary initiation system. Although initially designed for large mass blasts, the non-electric firing system is now used for all large hole blasting and in a simpler form for small (57mn diameter) holes.

Jan 1, 1982

The provision of electrical power is an important consideration in project development. The first step to be taken in this area is to assess the power requirements of the project. The alternatives of laking a supply from a power authority or providing local generation can then be considered. This requires additional defmition of the probable characteristics of the supply.The availability of authority power in Australia is limited by the extent of the state power grids. Recent developments now allow these grids to be extended and their load capacity increased to meet major load increases at less cost than was previously possible.The options for local generation include diesel, gas turbine, steam, hydro, solar and wind, each having its particular performance characteristics and costs. The choice of fuel for diesel, gas turbine, and steam plant likewise involves consideration of a range of factors. The arrangements adopted for five recent Australian remote development projects indicate how some of these aspects influence the decision on power supply.

Jan 1, 1990

The Mary Kathleen uranium deposit occurs in 1740-1780 M yr-old calc-silicate melasedimentary and mela-igneous rocks of lhe Corella Formalion which have been tightly folded into lhe Mary Kathleen Syncline. The Corella Formation consists of malic and felsic tuffaceous(?) calc-silicates, quartzile, and minor marble, conglomerate and basic volcanics. Garnet-rich rocks form semi-concordant and transgressive masses in the middle and upper portion of the sequence. Granite, gabbro and acid porphyry dykes also occur in the syncline.Uranium-rare earth mineralisation is closely associated with certain malic rocks and occurs wilhin or close to garnet-rich masses. At Mary Kathleen, uraninite grains are enclosed mainly by allanite which is dislribuled through massive garnet as an irregular honeycomb of interconnected shoot and lenses. The mineralisation occurs along strike from dioritic rocks and conglomerate and lies close to the axis of the Mary Kathleen yncline and adjacent to a major faull zone. All other localities allanite-uraninile mineralisation is broadly stratiform.The mineralisation is interpreted to occur at or near centres of basic volcanism. Garnet formation and uranium-rare earth concentrations are believed to be caused by the volcanism, and to be contemporaneous with it. The former is seen as alteration of a hot, saturated pile of volcano-sedimentary material and the latter as intermittent hydrothermal exhalation.Deposition, volcanism, garnet formation, uranium and rare-earth mineralisation, granile and gabbro formation, and tectonism are seen as a continuum of interrelated processes which operated throughout the period of format ion of the rocks in the Mary Kathleen Syncline.

Jan 1, 1985

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 E Yll÷, O HyvSrinen

Outokumpu has developed a new chloride leach process, called HydroCopper«, to treat copper concentrates. Chalcopyrite is quite refractory in leaching and in sulfate milieu an autoclave of high temperature and pressure is required. However, in the HydroCopper«-process copper sulfides can effectively be leached in atmospheric pressure using strong, aggressive chloride solution and copper (II) ions as oxidant. Copper is precipitated from the purified pregnant leach solution as copper (I) oxide, which is filtered and reduced by hydrogen gas to metallic copper powder, which is melted and cast into copper product. Sodium chloride formed in precipitation is decomposed in a chlor-alkali electrolyser, the products of which are circulated back to the process: sodium hydroxide to copper (I) oxide precipitation, chlorine gas to leaching and hydrogen gas to the reduction of copper (I) oxide. During 2003 - 2004 the performance of the HydroCopper«-process was confirmed in a demonstration plant processing one tonne of copper per day. It has been found to be applicable for different kinds of concentrates and can also tolerate a wide range of impurities. A significant advantage of the process is that gold can be leached as a chloro-complex and recovered with active carbon. HydroCopper« can economically recover copper from concentrates and process to a cast copper product. The best utilisation of the process is in most cases achieved when the plant is situated at the mine site. Higher recoveries are attained by the optimisation of the whole operation chain from the mine and the concentrator to the HydroCopper« plant.

Jan 1, 2005

By F Anthes, U Barow

Two tunnels are being bored using a æHydroshieldÆ in section 3.1 of the extension of the Underground railway line 5. At the end of the two tunnels, directly in front of the Hotel Adlon, the shields cannot be retrieved. The steel shell of the shield will be left in place within a sealed concrete block and the reusable components taken out through the completed tunnel. For the first time in Germany, an Underground tunnel is being lined solely by means of UNI rings. BerlinÆs Underground network is 165 km long and has 167 stations. Some 450 million passengers are transported annually. On account of the urban planning modifications that followed reunification, the network has to be adjusted, particularly in the city centre. The most significant project is the extension of the U5 from Alexanderplatz to the Lehrter Bahnhof. After completion, the U5 will be a continuous east-west traffic artery. It will provide a direct link with the new parliamentary and government district, open up new business districts and the cultural centre of the city.

Jan 1, 1999

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

By Adeloju S, McQuade CV, Riley SJ

Metal contamination of sediments can be an issue for minesites discharging water. Water sampling of receiving waters is frequently undertaken. Sampling and analysis of sediment is less common. The variability of receiving environments makes the formulation of a generic sediment sampling strategy virtually impossible. Each situation needs to be carefully assessed before sampling is undertaken. This paper outlines the approach taken for one such survey.The main factors that need to be considered in a survey of surficial sediments are sample representativeness and sample variability. A simple data set from one site within a regional survey is used to illustrate the importance of these factors. The metal content of sediment is shown to vary significantly over small spatial scales.The variability associated with the spatial distribution of samples within a site is shown to be the most significant source of variability in the study. This variability could bias the results of a study if not planned for in the sampling methodology. Taking multiple samples from within each site (sub-site samples) and combining the data gives a more representative indicator of overall conditions than a single sample. The optimum number of sub-site samples to be taken from each sampling site was found to be 15.It is shown that a composite of sub-site samples can give a good indication of the average site metal content, while considerably reducing the sample preparation and analysis effort.

Jan 1, 1998

By S Wotherspoon

At Kalgoorlie Consolidated Gold MineÆs (KCGMÆs) Fimiston Operations, located on the periphery of Kalgoorlie Boulder in Western Australia, roughly 7.5 million tonnes of rock are broken each month for the extraction of gold. With the close proximity of neighbours to the mining operations in the Chaffers Cut Back, special blasting techniques and tools were employed by KCGM to manage the blast induced vibrations and noise in this area. The i-konTM initiation system coupled with OricaÆs complementary modelling and analysis tools offered the complete blast management package. With these tools KCGM management and Orica Mining Services commenced an investigation into the benefits of electronic initiation. Prior to the commencement of electronic blasting, initial modelling was conducted to examine the vibration time waveforms and their frequency content, as these were expected to have an impact on vibration interaction with structures such as large buildings and urban dwellings. This work looked at results measured for a previous conventionally (pyrotechnic) initiated blast in the area and compared it to the results obtained when the blast was modelled with electronic initiation and faster timings. The predicted peak particle velocity (PPV) and structural vibration factor (SVF) were calculated. From the results it was concluded that the investigation into using i-konTM electronic initiation system and SHOTPlus«-i blast design software had some real potential to improve blast vibration management on the cut back. The use of the electronic initiation system and complementary software allows intricate timing designs to be accurately placed into blasts. The system has a number of working modes that allow either the precise design timings to be logged automatically into each detonator or to be manually logged where a variation from the design exists. Where such variations from the design occur, the electronic system permits the actual timings used to be uploaded back into the design file. This allows both design and real actual timings to be stored for future analysis or reference.

Jan 1, 2004

By Glenn R. J

Treatment processes are outlined for the recovery of rutile and zircon from the heavy mineral-bearing sands on the east coast of Australia. With the exhaustion of the higher grade deposits and the imposition of more rigid specifications for the finished products, strict metallurgical control has become necessary.A description is given of the methods used by The Titanium Alloy Manufacturing Co. Pty. Limited to control the operation of suction dredging, of wet concentration using fans and spirals, and of dry separation using high tension and electromagnetic processes. By applying these methods a plant designed for an output of 15,000 tons of rutile per year has been tuned to produce over 20,000 tons of rutile and a corresponding amount of zircon.Details are given of (a) the method of drilling to determine the extent and grade of the ore bodies, (b) a simple electrically-timed pneumatic automatic sampler, and (c) the methods developed for the physical estimation of quartz, rutile, zircon, ilmenite and "others" in the products of plant operation.The method used for calculating the metallurgical balance and the forms used for the reporting of production results are presented.Examples are given which show the value of this detailed production and metallurgical control of plant operation.INTRODUCTIONThe organization which is now known as "The Titanium Alloy Manufacturing Co. Pty. Limited" (T.A.M.Co.)-a subsidiary of National Lead Company-commenced operating at Yamba, N.S.W., in 1935. A mixed natural concentrate was at first simply dried and bagged and later was upgraded by the removal of silica and the lighter heavy minerals on shaking tables and, after air-drying, was bagged for export. At that time zircon was the most wanted constituent.

Jan 1, 1960

By T Berryman

The Fimiston reserve is being depleted at the rate of one million ounces per year; most of which is processed by the Fimiston plant, with the remainder being stockpiled. As for most other large open cut mines around the world, Fimiston has an excellent dispatch and tracking system. Reconciliation is used to determine how the various models used in mine planning (such as a reserve, budget and schedule models) are tracking against production. It is also used to gauge the performance of grade control estimation against production; however, analysing the results of this can be complicated and, at times, misleading. The reconciliation process involves adjusting the monthly production data to equal the mill reported tonnes and grade, plus the change in stockpiles. This adjusted number is then compared to the grade control reported tonnes and grade, the scheduled model (monthly planning model) tonnes and grade and against budget (Reserve) tonnes and grade. This paper includes explanations of all assumptions made in the reconciliation process, including the end of month closing stocks balance, the application of adjustment factors to the dispatch data to create a new balanced set of production data and the monthly sign off to comply with the Sarbanes-Oxley requirements of the North American owners. The reserve is reconciled by proved and probable classification. This tool is used to assess the robustness of the classification scheme utilised and identify any reconciliation issues as they arise. Within the Fimiston deposit there are still issues that are clouded by the assumptions made concerning the scale of observation, poor data support and the mining of the narrow lode areas of the deposit. The declared ore mined (DOM) number (which is defined in the paper) can be significantly affected by these assumptions, and these need to be clearly stated and understood when looking at the reconciliation data. The DOM tonnes and grade is a good indicator of real mine performance as it adjusts mined tonnes and grade to take into account the milled tonnes and grade each month, and prevents cumulative errors from building up in mine predicted dispatch numbers or end of period stockpiles. This number allows monthly monitoring of the mine to mill performance and allows valid comparisons to be made back to budgets and reserves over a period of time. KCGM uses three month rolling averages to monitor performance against reserve and budget models. This ensures that monthly distortions in the figures due to stockpiling issues or over mining in a particular period do not lead to false conclusions. Reconciliation performance over a longer period (12 - 18 months) is used to adjust reserve models should significant variance be observed. By closely monitoring the reconciliation performance at the Fimiston operation, fine tuning of all aspects of the grade estimation process from reserve through to grade control can be made. This allows the most accurate data to be used when planning from reserve data for the Life of Mine Plan through to grade control data for short-term mill feed.

Jan 1, 2006

In the 100 years since the formation of The Australasian Institute of Mining and Metallurgy there have been significant changes in all aspects of the mining industry.A number of the changes have been driven by technical evolution or necessity, others have been driven by developments in the application of the products produced from the mining of minerals. Other changes have been driven by shifts in community values.

Jan 1, 1993

The complexities of mining in current economic conditions, where ore extraction schedules are varied on a weekly basis so as to ensure constant supply to the process plant, can result in a number of scenarios that pose geotechnical challenges. This paper presents a case study where alterations in the mining schedule of a particular mine resulted in the necessity to mine under a large uncompacted embankment, ie integrated tailings and mine waste land form. To effectively ensure that ore recovery was maximised, a well-designed slope monitoring system to evaluate design performance and to provide timely warning of impending failures was imperative. In order for an appropriate slope monitoring strategy to be developed, a thorough understanding of the potential slope failure mechanisms, capabilities and limitations of available monitoring techniques is required. Communication of the monitoring results and response strategy to alarms generated by monitoring systems must also be carefully considered to maximise effectiveness. The results of preliminary stability modelling can be used to guide the design of a monitoring system, which in turn can then generate data which can be used to iteratively refine the geotechnical model. This paper illustrates the development and implementation of a slope monitoring system and associated communication system, using the Daydream embankment at Fortescue Metals Group's (FMG's) Cloudbreak Operations as a case study.

May 1, 2010

Chlorine as a lixiviant for gold possesses a number of significant chemical and Idnetic advantages over cyanide but because of its corrosive and vaporous nature the method of implementation needs to be significantly modified. At comparable reagent concentrations the dissolution rate for gold in the C12/Cl- systems is some 10 - 100 times that achieved in the 02/CN system. The dissolution rate in the chlorine system is largely a function of the concentration of C12, Cl- and pH. Under conditions of low Cl', (less than 50 g/1), the dissolution rate begins to drop off dramatically over the pH range from 3 - 4. Increasing the level of dissolved chloride ions shifts the pH of this rate reduction to around pH 5 at 100 g/l NaCl, and to around pH 6 at 300 g/l NaCl.

Jan 1, 1991

This paper presents results of the experiments carried out in Beth Energy No. 33 Mine for the purpose of alleviating problems associated with cutter roof. Cutter roof problems have delayed the advance of the entry development considerably and maintenance cost of these entries was very high due to the requirement of very extensive and heavy artificial supports. The study includes assessment of the problem, investigation of the geology and lithology of the mines, study of in-situ stresses and corrective measures to combat the problem. Two approaches were selected as the corrective measures: 1) implementing yield pillar concept in order to reduce the effects of in-situ horizontal stresses, 2) designing an effective roof reinforcement system and application procedure. Results of this study revealed that roof strata is weak and in-situ stresses are very high at the problem area which results in development of cutter roof. Implementation of yield pillar concept was found to be ineffective because cutter roof often developed at the entry face concurrent to the development. However, proper design and implementation of roof reinforcement system stabilized the roof and eliminated roof caving during both entry development and retreat of longwall face, despite existence of the cutter roof, at a much lower cost.

Jan 1, 1992

By Mould G. R

The paper presents a general background to the subsidence research programme being undertaken by the Department of Mineral Resources and Development in New South Wales. The results of the studies undertaken over the last ten years are summarised. The differences between these results and those obtained by the National Coal Board are discussed. The results of a study carried out on the effect of total extraction beneath a freeway in the southern coalfields are discussed in some detail. The procedures developed for the const- ruction of a 500 mm diameter natural gas pipe- line crossing a number of collieries in the northern coalfields are also outlined. The future direction of the Department's subsidence research programme is discussed.

Jan 1, 1980

A synthetic gold-silver telluride material (mainly sylvanite) has been prepared and its physical and chemical properties checked. Flotation tests using a Hallimond tube were conducted using commercial xanthate collectors. At collector concentrations of 10-3M with the addition of 5 × 10-4 M CUS04, no obvious differences in the mineral recoveries were seen irrespective of whether amyl, secbutyl, isobutyl or isopropyl xanthates were used. However, when the concentration of xanthate was reduced to 10-4 M or in the absence of the copper sulphate activator, the effectiveness of the collectors was in the order: amyl > secbutyl > isobutyl > isopropyl > ethyl. Changes in the slurry pH appeared to have little effect on the recovery of the telluride mineral.Leaching tests of the precious metal telluride showed that both gold and silver dissolve in alkaline oxygenated cyanide solutions but at a much lower dissolution rate than metallic gold or silver. Both leaching tests and electrochemical measurements indicate that the dissolution rate of gold-silver telluride is controlled by the pH and cyanide concentration of the leachant.Roasting the gold-silver telluride materials in air at temperatures between 550 and 750°C resulted in its decomposition into a metallic gold-silver alloy and tellurium dioxide.

Jan 1, 1994

By Best R. J, Poulos H. G

The method for design of primary roof support for the large todoidal cavern constructed to house the Sydney Opera House parking station is presented. The cavern was constructed with 5 m of rock cover beneath Sydney's Royal Botanic Gardens. Design of rock reinfonnent using a combination of fully grouted rock dowels and Macalloy bars was based on control of horizontal shear movement along bedding features in the roof. A combination of linear arch type analyses and non-linear jointed finite element analyses were used in the design study together with an analysis of the shear resistance offered by fully grouted bolts under shear deformation.

Jan 1, 1993

By Browne TJ

On 13 October 1993, a shallow earthquake registering 7.1 on the Richter Scale occurred near Tauta in the Finisterre Range of Papua New Guinea (PNG) killing 37 people. The aftershock series lasted three months and resulted in considerable landslide damage that destroyed villages, food gardens and airstrips, and blocked rivers causing catastrophic flooding. These effects have irrevocably altered the form of many of the valleys and rivers draining into the Markham and Ramu valleys.The earthquake occurred in a pilot study area for a landslide hazard mapping project being carried out by the PNG Geological Survey that commen-ced in April 1993. Comparisons made between areas identified as unstable during the study with those damaged by the earthquakes show good correlation.It is concluded that aerial photograph and Landsat TM imagery interpretation can be used with a high degree of confidence to identify potential landslide hazards in mount-ainous terrain. Landslide hazard maps are promoted as a tool for use in the route planning of roads and powerline corridors, as well as for identifying vulnerable communities.

Jan 1, 1994

By M Ljunggren, M Lundh

Dissolved air flotation (DAF) in wastewater treatment as a separation process of submillimetre biological flocs is based on the generation of bubble/floc aggregates. DAF is a complex process but has got advantages, such as allowing a high hydraulic load, compared to sedimentation. A thorough knowledge of the physics of the DAF process is, however, still lacking. This paper will present results of experimental studies on three aspects of significance to the separation process û the flow structure in the flotation tank, rise velocities of aggregates, influence of floc size on the separation efficiency. Flow structure. Measurements were performed in a pilot plant mapping and visualising the velocity field. The dispersion water (bubbles) had a decisive influence on the flow structure due to the effect of the bubbles on the bulk water density. Stratified conditions with a less dense, bubble-containing upper layer and a clear water, denser bottom layer were important for a good separation. A simple model of the stratified flow structure was elaborated making it possible to interpret the function of the aggregate rise velocities. Bubble/floc aggregates. The dynamics of single flocs, bubbles, aggregates were visualised using a borescope + CCD video camera + digital recorder + image analysis. Sequences of video frames made it possible to determine the rise velocities of the single aggregates. These velocities were found to be in the range 1 - 9 mm/s with a tendency for large flocs to have higher rise velocities. Separation versus floc size. The floc size distribution was measured in the DAF process. Data from three different DAF cases showed, that large flocs (> about 100 ¦m) were entirely separated, whereas small flocs experienced a less good separation. It was, moreover, found, that a very significant separation of flocs took place in the very upstream end of the separation zone in a pilot plant case.

Jan 1, 2005