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By E Hernandez, I Agustian, W Kusumohastuti

PT Freeport Indonesia is completing the first underground gyratory crusher excavation at their Deep Mill Level Zone (DMLZ) mine located in the mountains of Jayawijaya, District of West Papua, Indonesia. DMLZ is an underground block cave mine with an expected output of 80 000?t/d and a scheduled production start in 2015.In order to deliver crushed ore to the mill through the existing conveyor belt, the DMLZ block cave mine will construct two 1000?kW 1.6?×?2.3?m gyratory crushers with their own respective ore flow conveying systems underground. Each crusher is composed of top, middle, and bottom chambers with an ore bin. This system includes a series of high capacity conveyors approximately 5 km in length including transfer stations and support facilities.The development methodology required a combination of lateral development by jumbo drilling machines and vertical development by mechanised raise climbers (MRC) due to the complexity of the chamber design.This paper will discuss the project scope, design and development methodology, ground conditions, innovative survey controls, and the challenges faced due to the remote location.CITATION:Hernandez, E, Kusumohastuti, W and Agustian, I, 2014. Excavating the first underground Gyratory Crusher at the Deep Mill Level Zone mine, PT Freeport Indonesia, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 43–50 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

By A A. Latscha, D O’Connor

Increasing orebody complexity, restrictions in ground access, and longer lead times for disturbance approvals, have generated the need for the Resource Development Team within Rio Tinto Iron Ore (RTIO), to explore optimised drill design techniques that deliver resource conversion value while maximising program outcomes. In response to this challenge, the Team initiated a case study to produce an AI assisted/designed drill program using a non-machine learning AI. The case study involved the assessment and implementation of an AI generated drill program at one of RTIO’s Pilbara iron ore deposits, located in the Hamersley Province of Western Australia. The Mineral Resource is currently classified as 100 per cent Inferred. Access constraints inherent to topography, and the presence of exclusions zones have prevented adequate drilling coverage, resulting in lower resource confidence and a poor definition of the orebody extents and geometry. The drill campaign, planned in Q1 2023, needs to consider access constraints, complex topology and the limitations related to additional ground clearance, while addressing the requirement of improving orebody knowledge. The drill plan had to address two objectives. The first and main aim of drilling was to upgrade the Resource Classification to allow for possible conversion to Ore Reserve. The input for this objective was a volumetric representation of the areas currently not meeting pre-defined quantitative Resource Classification upgrade criteria. The second objective was to better define the orebody extents and geometry. For the second objective, the input to the drilling optimiser was a volumetric representation (blocks) of the areas of high uncertainty in the mineralisation/waste boundary, which were defined using an indicator conditional simulation technique. The drilling optimiser output was a range of compliant drill plans. A set of KPIs based on economic and orebody knowledge criteria were used to assess the plans and to select the most optimal drill design to be drilled in 2023. The geology and management teams were able to make better informed, objective decisions using the trade-off between cost and orebody knowledge gained. As part of the assessment, the AI generated plans were compared to our current planning practises. The AI assisted plans, when gauged against the project KPIs, showed clear and measurable improvements in both meeting project objectives and in managing operational risk.

May 24, 2023

By S F. Rogers, P W. Booth

Digital photogrammetry is revolutionising the task of geotechnical mapping of jointed rock masses and has greatly increased in popularity and sophistication in recent years. Modern commercially available digital photogrammetry software systems can provide geotechnical practitioners with a user friendly tool for rapid data acquisition. The data can be acquired remotely from large exposure areas, some of which may be otherwise out of reach due to restrictions on time, access or safety.Photogrammetry is a complimentary technology to discrete fracture network (DFN) modelling because it can provide the large, statistically significant, spatially located geotechnical data sets required to produce the most robust results. It also provides the flexibility to selectively map structures at a range of scales, depending on the focus of the DFN modelling.Integration of the interpreted rock structure data derived from photogrammetry with modern DFN modelling methods really advances the rock engineering process. The ability to generate 3D fracture models driven by the statistical structural data and conditioned to the features observed by the photogrammetry yields a synthetic rock mass on which improved design methods can be applied. The generation of multiple equi-probable conditioned DFN models allows the use of probabilistic methods for assessing kinematic stability, rock block size distribution as well as a range of other applications.CITATION:Rogers, S F and Booth, P W, 2014. Integrated photogrammetry and discrete fracture network modelling for improved rock mass characterisation and engineering design, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 203–208 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By W Zeng, D Walker, D Cai, E Baafi

"The efficiency of the truck-shovel haulage system is significantly influenced by the truck fleet size. A discrete event simulation model with 3D animation has been developed to estimate the productivity of a truck-shovel network system, shovel efficiency, truck cycle time, truck utilisation and the optimal fleet size. The simulation model considers the dynamic variability of traffic conditions and also the truck as an individual entity. The resulting truck cycle time was found to be realistic and thus providing a better tool for strategic mine planning.Citation:Zeng, W, Baafi, E, Walker, D and Cai, D, 2016. A 3D Discrete Event Simulation Model of a Truck-shovel Network System, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 265–273 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

Entry of personnel under a vertical raise bored hole is not standard practice in Australia. Where access is required below a rise, mining operations must be confident that they understand the capacity of the ground control specified and installed. Physical modelling was conducted on Callie mine to evaluate the performance of 5 mm steel wire weldmesh secured to the base of a vertical raise bored hole of 1.4 m diameter. Joint orientation data was used with Unwedge to calculate a series of potential wedges likely to form within the rise. The mass of the most likely wedges were then replicated by collecting rocks in 5 kg increments (¦10 per cent), which were allowed to freefall onto installed mesh at the base of a 40 m vertical rise. The results indicate that two sheets of mesh can retain a freefalling rock of at least 20 kg mass although rupture of strands can result. This paper outlines the test conditions, expected results based on theoretical calculations and actual outcomes of the testing.

Nov 25, 2010

The Resource Management Act 1991 (RMA) and the Crown Minerals Act 1991 (CMA) both came into force on 1 October 1991. The purpose behind RMA was to integrate the existing laws dealing with town and country planning, land subdivision, water and soil, minerals and energy resources, coastal management, air pollution and noise control into one omnibus Act. Originally, there was a section in RMA dealing with minerals. However, this section was taken out of RMA and a companion piece of legislation - namely CMA - was passed with RMA.

Jan 1, 1994

By Beech-Jones J. M

At Port Latta in Tasmania, Savage River Mines operates vertical shaft furnaces for the firing of pelletised magnetite concentrates. At times the temperature profile of the furnace has changed markedly, necessitating the- burning of greater quantities of fuel to maintain good pellet quality. A study of the oxidati=of magnetite concentrates was under- taken because this exothermic process supplies much of the heat required to indurate the pellets. Using the thermal analyses methods, different magnetite concentrates from Australian and overseas were heated in air under identical conditions, to compare rates of oxygen uptake and of heat release. In addition, a compari- son was made of the oxidation behaviour of different particle size fractions of a selected concentrate. Particle size analyses, x-ray diffraction and dilatometer tests were used to aid inter pretation of the thermal analysis traces. The investigation emphasized the importance of particle size and ferrous iron content in determining' oxidation rates from the commencement of heating.

Jan 1, 1974

Calculations of the temperatures of metal, coke, and gas at any level in the cupola furn~ce can be carried out by means of heat balances, using data obtained from experiments with an 18 in. experimental cupola. The results can, to a certain extent, be verified by means of heat transfer calculations.The curves thus obtained, showing the variation of temperature with height in the cupola, provide a valuable picture of the heat transfer processes in a shaft 'furnace.INTRODUCTIONThe Brown Coal Research Laboratory, of the University of Melbourne, has been engaged in recent years on a programme of iron-melting tests in an experimental cupola furnace.Although the ultimate aim of this work is to develop brown coal char as a cupola fuel, most of the experimental work so far has been with conventional coke. The testing programme was designed to provide information on the effect of variables such as blast rate, metal-coke ratio, and coke size on the overall melting process, e.g. melting rate, temperature of metal tapped, and stack gas composition.However, in many cases data were obtained on conditions inside the furnace by measuring temperatures and gas compositions. The aim of the work described in this paper was to qevelop a method for using this data to obtain information on the processes taking place in the cupola.Very little research has been done on the combustion of fuels in shaft furnaces. Early work on this subject, as well as the initial stages of the Brown Coal Research Laboratory's programme, has been discussed by Evans (1959). The use of probes for obtaining information on conditions in the interior of a shaft furnace was pioneered by Belden (1913)...

Jan 1, 1963

By J E. Everett, K Jupp, T J. Howard

Precrusher stockpiles are designed principally as buffers to decouple the mining and processing operations. They are usually paddock dumped or dumped over a face to form fingers by dumping haul truckloads and reclaimed by front-end loader in an ad hoc manner. In addition, they are often not built and reclaimed to completion but continually added to and extracted from. While this design suits the mining process and is operationally simple, there can be little confidence in the grade of the ore that is fed to the crusher. This makes short-term grade control difficult and reconciliation back to the mine face imprecise. Well-designed and operated precrusher stockpiles can overcome these deficiencies.The different types of grade variability in mining are reviewed in this paper. The role of precrusher stockpiles in reducing short-term variability is discussed and their ineffectiveness in addressing long-term variability is highlighted. Their role in removing the serial correlation of the extracted ore is explained.Precrusher stockpiles carry out the four, at times competing, objectives of storing, buffering, blending and grade separation. Their actual design and operation result from a compromise between these four competing roles. These roles are explained in detail along with the advantages and disadvantages of the different types of precrusher stockpiles. The recommended blended-in blended-out stockpile (BIBO) design is discussed in detail. Matched pairs of BIBO stockpiles of limited tonnage built and reclaimed to completion retain the best knowledge of grade and facilitate the reconciliation process.Simulation studies have been carried out on BIBO stockpiles to understand the blending opportunities of the different options for building and reclaiming, and to identify the methods that achieve maximum blending. It was found that laying down rows in one direction and reclaiming across these rows gives the best blending. Matching the width of the reclaim face with the daily crushing requirements is also important. The length of the rows, and building in either one or two layers has little effect on the extent of blending.Appropriate design can provide a reasonable compromise between the four objectives.CITATION:Jupp, K, Howard, T J and Everett, J E, 2013. The role of precrusher stockpiling for grade control in mining, in Proceedings Iron Ore 2013 , pp 203-214 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

The mining industry has a well deserved reputation earned over the years for innovation, engineering, management and the quick application to mining of emerging technology. The cumulative result is the economic exploitation of lower grade resources. The developments during the last decade have done nothing to tarnish the reputation. There are many that come easily to mind: the use of contractors for both surface and underground operations, a trend toward mine management contracts, the increasing recognition of the economic potential of ground support, and the development of physical measures to achieve it, - sophisticated measures to analyse blasting , and thus improve fragmentation, - instrumentation to assist geotechnical appraisal, - the development and application of the powerful and flexible, excavator, - the evolution of measures to improve grade control, - massive improvements in equipment productivity and reliability built largely around the application of hydraulics, - the development of powerful computer packages for orebody modelling, mine design and extraction, - simple "dense" fill systems, - maintenance management techniques including the greater use of off-site maintenance of exchange components, - the utilisation of communication systems for data transfer.

Jan 1, 1989

By K Bojarska

Examination of wastes aimed at evaluation of their usefulness for utilisation needs applying modern chemical testing methods. The XRD-XRF-ICP-GC/MS set of test methods constitutes an integrated testing system enabling ecochemical examination of wastes. As far as the problem of time-consuming operations is concerned, the offered system fits in a market-oriented field of activity of accredited chemical laboratories. Within a reasonable period of time, it allows to obtain information about mineralogical and chemical properties of wastes. It provides full range of information beginning from mineral composition (XRD) through chemical composition including the number of elements and organic compounds (XRF-ICP-GC/MS) up to the contents relating to the amounts of ingredients, both organic and inorganic in the leaching tests (ICP-GC/MS). The XRD-XRF-ICP-GC/MS testing system proves to be of particular importance in obtaining reliable results enabling to perform precise assessment (from ecochemical point of view) of wastes to evaluate their usefulness for utilisation in building materials, in civil engineering and reclamation works.

Jan 1, 2003

X-ray analysis of polycrystalline powder samples has grown beyond its roots in the world of laboratory research and is now regarded as one of the most powerful industrial process-control tools in the field of building materials. This is the key to characterise the element and crystalline phase composition of the material. This is due largely to the development of industrial X-ray analytical systems such as PANalyticalÆs twin solution, which has transformed the advanced analytical techniques born in the laboratory into a robust, workmanlike and easy-to-use tool for todayÆs heavy industries. The increasing use of alternative fuels makes the Bogue method less reliable. Therefore, the real phase quantification by the Rietveld method is the only choice. Additional fine-tuning of the Rietveld method by using alternative methods guarantees the most accurate quantitative results. Moreover, the recent development of ultra high-speed X-ray detectors allows for æon the flyÆ quantitative X-ray diffraction analysis and a truly interactive process and quality control.

Jan 1, 2008

By B Cook, M Karakus, J Light, E K. Chanda

The aim of this research is to develop a model through which the appropriate paste recipe parameters, for example solid content and cement content, can be derived given the stope specific requirements such as stope dimensions, required strength and curing time. A large number of samples and uniaxial compressive strength (UCS) tests were conducted at the Angas Zinc Mine (AZM) paste plant and testing facility. Samples were varied in tailings solids content, cement content and sand content. The results of this testing were modelled to determine the UCS relationship to each of the parameters. The output of this modelling was an easy-to-use program that outputs the design mixture given the stope dimensions and required stope backfill-curing time. This allowed flexibility within the mining schedule for curing times of cemented paste backfill stopes. The optimised schedule using the stope specific mix design, when compared to the standard 14-day curing time used previously, resulted in a smoother weekly mine production schedule. For the modelled 12-week period (one quarter) the 14-day curing time would result in an eight-day shutdown of the mill. The cost for each shutdown is in the order of $125 000/d. Due to the unique nature of each mine’s tailings, this exact outcome would not be directly applicable to another paste fill site. However, the process in this report could be followed for another site to achieve a system similar to the output of this project. This would ultimately lead to a more optimised backfill and stoping cycle and a more optimised mine.CITATION:Chanda, E K, Karakus, M, Light, J, Cook, B and Harris, A, 2014. Optimisation of the paste fill cycle at Angas Zinc Mine, Strathalbyn, South Australia, in Proceedings 12th AusIMM Underground Operators’ Conference 2014 , pp 259–264 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 24, 2014

The basic principles of mineral valuation were recognised and propounded at the beginning of this century and have remained virtually unchanged since then. Valuation is seen as a two part process commencing with a technical examination of the mineral property followed by a manipulation of the results of the technical examination in order to determine the monetary value of the project. A thorough and competent technical examination was seen then and remains now as the essential but not sufficient foundation for reliable valuation. All authors stressed the need to maintain the integrity of the data base and to ensure adequate coverage of all relevant aspects. The monetary valuation process through most of the first half of this century was mainly based on the Hoskold two rate method, derived from the formulae for valuing annuities but modified to provide explicitly for recovery of capital. Though the basic principles of valuation have not changed significantly, the means of implementing the components of the technical examination, the styles of deposits being evaluated and the mechanisms of monetary valuation have changed dramatically. Despite all the technological improvements, however, mineral

Jan 1, 1995

By Manzoori AR

From a detailed combustion testing program and earlier experience with Leigh Creek coal, the Electricity Trust of South Australia (ETSA) gained a wide insight into the use of low rank coal fired boiler plant. This work is fundamental for the selection of boiler design parameters and other details which in turn determine the correct coal deposit selection for future power station development. In addition it gives boiler designers a good indication of the measures required to give reliable plant operation. Extrapolation from experience with existing plant, the designers main source of information, was not considered appropriate because of the lack of experience with similar coals. Brown coal beneficiation is also being assessed by ETSA in an attempt to improve the coal quality by the pretreatment of the raw coal prior to combustion in future coal.fired boilers. ETSA is also involved in the development of circulating fluid bed and gasification processes to determine whether these alternative processes are a more viable method of utilising the South Australian coals than pulverised fuel firing.

Jan 1, 1987

Feasibility studies in the development of mining projects are fundamental to most investment decisions. It is important that the issues addressed and the degree of detail involved in feasibility studies are consistent with the investment decisions to be taken. Emphasis should be placed on a thorough analysis of critical project parameters prior to detailed investigations being undertaken into other activities which are not relevant to the decisions at hand. Therefore, the issues to be decided upon should be influenced significantly by the stage of development of the project and by the reliability of technical and financial information used in the study. Some of the more critical parameters of feasibility studies are commodity prices, inflation rates and discount rates. Advice is given on the selection of these inputs and also on their application in the feasibility study as the project progresses through its various development stages. The feasibility study should involve not only a formal evaluation of project economics but also an analysis of all project related risks and a comparative analysis of projects competing in

Jan 1, 1983

By J Wei, X Lan, F Wang

This paper presents a quantitative assessment model for the assessment of environmental load in gold production, which is based on environmental ecology, Life Cycle Assessment (LCA) and artificial neural network. In LCA evaluation indexes include resource consumption, energy consumption, gas waste, liquid waste, solid waste and so on. Each item represents an aspect in gold production while their combination reflects the relationship between gold production and environment. In this paper an utility function of evolution index on environmental load is given by linear or non-linear transformation, which changes evaluation indexes with different dimension into an equivalent value in range of [-1, 1]. This paper also provides a new approach to make decision on the weight for quantitative assessment with the help of a three-layered artificial neural network. The proposed approach in this paper has been successfully used to a real synthetic assessment for the environmental load in gold production, which include seven kinds of different operational technologies in China. The applications prove that the new approach is successful and reliable. It provides a new tool for the assessment of environmental load of the gold production.

Jan 1, 2003

By Edwards A. B

A suite of specimens from the newly developed Black Star copper ore body at Mount Isa was made available for mineragraphic study by the Mount Isa Mines, Ltd. The specimens were selected as representative of the different phases of mineralisation found in the ore body, rather than with a view to furnishing a complete cross-section of it; and the examination has been carried out with a view to ascertaining (1) the nature, extent and association of the arsenic, antimony and possibly bismuth, minerals in the ore, (2) the mode of occurrence of silver in the ore, and (3) whether galena and sphalerite occur in minute forms well below the sIzes readily observed in hand specimens.Analyses of the January to June, 1944, mill head composites show that the proportions of the elements Ag, As, Sb and Bi in the ore are as follows:Ag 0.000013 = 0.35 oz./tonAs 0.024Sb 0:002Bi 0.0005The copper content of the mill heads ranges from 3.5% to 4.75%, the lead content from 0.03% to 0.08,% and the zinc content from 0.09% to 0.23%.MINERAL COMPOSITIONThe specimens range from massive sulphide ore, consisting of areas of chalcopyrite, pyrrhotite, and rarely sphalerite, from 1 to 3 cm. across, to fragments of extremely finely banded pyritic shale in which no minerals other than pyrite are visible. The gangue associated with the massive sulphides is chiefly dolomite, and sometimes white quartz. The pyritic shale fragments show evidence of shearing and faulting on a micro-scale, the fractures sometimes being filled with sulphides and vein minerals.The ore minerals found in the polished sections are pyrite, arsenopyrite, marcasite, sphalerite, chalcopyrite, valleriite, chalcostibite, galena, dyscrasite, jamesonite, magnetite, gold, graphite and rutile.Pyrite (FeS2)Pyrite occurs chiefly in two forms according to whether deposition took place along the bedding planes or along the intersecting faults and fractures. Deposition of pyrite along the bedding planes of dense, thinly banded shales ha,s produced a metasomatically altered shale in which the pyritic bands are from 0.02 to 0.03 mm. wide, and alternate with bands...

Jan 1, 1945

The products required by customers today have become far more complex and consequently more demanding to handle. And thereÆs the dilemma. Nowadays, people tend to stick to a trade for just a few years instead of for a lifetime, and this means that the customerÆs employees cannot be expected to get more than general knowledge of how to handle modern mining and construction equipment. To meet this challenge, major steps are being taken by suppliers to make their æmusclesÆ more user-friendly. Also the supplier is assuming a larger share of responsibility for the product including operators training, supply maintenance services and, in many cases, performance guarantees. In other words, the supplier is today supplying a function or an activity rather than just muscles. Some of the new generation drill rigs have been on the market for a few years and reliable experience has been collected and is addressed in this paper. Some of the information is well supported by figures while others are just statements from users of the rigs.

Jan 1, 2005

By Sehic OA

One aim of testwork and flowsheet development is to ultimately provide a reliable and flexible plant that is simple to operate and maintain. Testwork can indicate amenability of ores to CIP treatment and provide a basis for process design and economic appraisal. Batch cyanidation and CIP tests are often sufficient for small projects. Continuous multistage test rigs can be operated to simulate plant operation and to provide data for flowsheet optimisation. Operating requirements, gold recoveries and potential problem areas can be anticipated at an early stage with more confidence. Subsequent project development involving decisions on the basic flowsheet, equipment types and general plant arrangements are based on practical considerations and experience. Computer aided process modeling and economic appraisal can be useful in analysing various tradeoffs, firming up the flowsheet and equipment sizes, and in specifying operating targets for the future CIP plant. INTRODUCTION Carbon-in-pulp (CIP) technology which has developed rapidly since 1974 is now accepted as an economically and technically viable process for the efficient recovery of gold. This paper describes testwork and flowsheet development procedures used for CIP evaluation and design.

Jan 1, 1982