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By L Keeney

Geometallurgy is not a mechanism designed to replace current geological and metallurgical deposit characterisation but an added component required to understand orebody variability. Current geological characterisation approaches focus on understanding deposit genesis aimed at identifying new mineralised regions and metallurgical characterisation determines parameters required for engineering design of processing plants. Geometallurgical integration has the task of drawing on aspects of each stream to enable spatial mapping of performance indices across a deposit. It is a complimentary activity to current practice and adds a new dimension to orebody knowledge. Although the notion of conducting an integrated geological and metallurgical analysis is not a new concept, limited publications exist in the field proposing integrated methods, with several technical issues existing in current geometallurgical integration approaches. An iterative method drawing on existing geological and metallurgical characterisation and new measurement tools and inputs is proposed. The integrated method comprises of discrete components dynamically linked together through iterative feedback loops with each component having a specific purpose achieved by applying a range of data acquisition technologies and statistical tests. The key outcomes of the method are:overcoming the lack of optimised geometallurgical domains relevant to processing performance,development of a rigorous approach to identifying parameters controlling processability,improved protocols for relevant metallurgical test data and sample selection, andability to generate greater data support to enable rigorous geostatistical modelling of geometallurgical attributes. This paper outlines the integrated mapping and modelling method developed and draws on multiple data acquisition technologies applied within the AMIRA P843 GeMIII Project.

Sep 5, 2011

By K Knorr, S Birch

The mineralogy of new certified-reference-materials (CRM) for X-ray fluorescence from Western Australia (ASCRM 030 to 035) was analysed by X-ray diffraction using the BRUKER energy dispersive one-dimensional detector LYNXEYE-XE. The samples were studied using standard-less quantitative phase analysis, based on the Rietveld method. This method delivers the relative amount of crystalline phases. All materials were found to be high-grade iron ore predominantly consisting of hematite and goethite and very low amounts of magnetite. In addition, the gangue mineralogy was characterised. It consists of low-per cent amounts of carbonate (siderite/calcite), quartz, kaolinite, chlorite and gibbsite.Furthermore, all samples were analysed with the external standard method. This is an elegant way to probe for amorphous content without adding an internal standard. All six samples were found to contain up to 16 per cent amorphous or nano-crystalline material.CITATION:Knorr, K and Birch, S, 2013. Mineralogy of new Australian x-ray fluorescence standards, in Proceedings Iron Ore 2013 , pp 269-274 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By Xianguo C, Baoqi S, Shaozhong Z, Huiling Z, Zhengbing C

Acidless and fluoless flotation is a new method for separating feldspar from quartz at the natural pH value of tap water in the absence of any acid and fluoride and other inorganic reagents. The paper introduces the production application of this method in plants and research results on the mechanism involved in the flotation method.

Jan 1, 1993

The Imperial Smelting Process (ISP) for the simultaneous smelting of zinc and lead was developed at Avonmouth from the 1930's with activity intensifying in the late 1940's/early 1950's. Present operations are based around the No.4 furnace which was built in 1967. Development during the 1980's has been driven by the need to sustain operations at low metals prices and has been aimed at reducing manning whilst increasing output. Although hit by several major plant disruptions, progress has been steady, culminating in a ú10 million capital programme in 1988?89 to upgrade the operation. The most important technical developments, reflecting the needs of the 1990's have, in the sintering area, included improvements to feed conditioning and sinter quality, a 20% uprate in production capacity by debottlenecking, and pilot work leading to the installation of a Boliden-Norzink mercury removal plant. In the smelting area the ISP furnace has been rebuilt, with a redesigned bottom section to eliminate earlier operating sensitivities, and to achieve higher blowing capability, and at the zinc refinery the columns have been rearranged for more flexible operation and higher capacity.

Jan 1, 1989

By Marshall T. E, Finfinger G. L

Gulf Coast domal salt mining operations have had sporadic encounters with methane gas emitted without any warning. In virtually all confirmed cases, the methane was localized in methane enriched zones. In a few cases large quantities of methane were expelled rapidly with salt outbursts, resulting in dangerous methane concentrations. Estimates of methane liberated by face blasts in methane-enriched areas is needed in determining how much air should be supplied to the face for proper dilution. A relationship between the gas content of salt samples collected from the face and the amount of methane liberated would be helpful in estimating how much methane will be produced by a face blast. Little is known about the layering or stratification of methane in large area-low velocity airways. This publication reports on three tests conducted by the Bureau of Mines which monitored the immediate return air of four faces during blasting. The test locations were in a methane gas-enriched section that had previously experienced two large outbursts and many smaller ones. A comparison was made between gas content values of face salt samples from the dissolution test and the gas liberation quantities. The characteristic movements of the methane in a large room with low air velocities were charted. This will help to better understand the factors involved in proper placement of methane sensors as a warning system.

Jan 1, 1988

Mount Isa Mines' Hilton Mine was brought into large-scale production in 1990/91 at a time of sharply falling metal prices. To ensure the operation's survival and eventual prosperity there was an urgent need to reduce operating costs and increase revenue. A target of a 40 per cent increase in productivity over five years was set. Strategies to obtain the required improvements were developed on the basis of greater involvement and increased contribution from the workforce, major changes to the mining methods and the development and application of new technology. This paper describes the organisational, operational and technological changes that have been implemented at Hilton and presents the results achieved to-date.

Jan 1, 1993

By P Jonsén, S Larsson, M Parian, B I. Pålsson

The question of effective energy utilisation in grinding mills is not new. There are several conflicting arguments about tumbling mills, whether the efficiency is around 1 per cent or maybe 10 per cent, or even much lower. The energy not used is assumed to be lost as heating of the pulp, the grinding mill body, the charge, generation of shock waves and vibrations, etc. Stirred media mills on the other hand are generally considered to have better energy utilisation, but their energy efficiency is still not that clear. To shed some light on this a pilot-scale, wet stirred media mill was investigated over a range of operating conditions. The wet stirred media mill is a Drais PMH 5 TEX pearl mill fitted with an electric motor at 11 kW. It has been investigated over a range of operating conditions to try to balance the dissemination of the input energy in forms of the net grinding energy, mechanical energy losses, and the heating transferred to the pulp, the mill, the charge, and the cooling water. It is found that approximately 20–40 per cent of the input energy accounts for the grinding process. Also, that the difference between gross and net input electrical energy is mainly disseminated as heating of the pulp and cooling water. Mechanical energy losses appear to be much smaller than the heating effects. The use of a dispersant seems to mainly influence the heating effect.

Aug 24, 2022

By Lama R. D

The Australian underground coal mining industry is undergoing major changes. This paper analyses the technologies presently being researched in mines, and discusses their utilisation as major contributors in the underground mining of coal in Australia over the next 20 years. It describes the problems that underground mining of the year 2000 will face and the possible solutions to those problems based upon results of present day research. Methods, equipment and organisational requirements are outlined. Developments in micro-electronics, computerisation and monitoring will require a new look into human resource development, education and training, and organisation to meet the challenges of the 21st century. The mining system's philosophies of the future are Outlined.

Jan 1, 1986

By H Kundapen, B R. Bolton, H Davies

The Ok Tedi porphyry copper-gold mine is located in the Star Mountains of Western Province, Papua New Guinea. Open-cut mine commenced in 1984 and is due to cease around 2010. The mine produces a total of 88 Mt of waste annually including 58 Mt overburden and 30 Mt tailings, which are discharged directly in to the Ok Tedi River. Mine derived wastes are transported downstream and deposited within the river channel in a variety of bar forms. The prevailing hydrogeological conditions including, velocity, competency, capacity, gradient, grain size and specific gravity, control the deposition and segregation of these sediments. Periodic exposure of the reactive sulfides to oxygen during fluctuations in the river discharge may result in oxidation, localised acid generation and liberation of metals into solution. To evaluate the significance of this issue, Ok Tedi Mining Limited initiated an investigation of the sediments deposited in the upper Ok Tedi River as part of its overall ARD Management Program. The specific objectives were to: evaluate the acid-forming characteristics of identified high sulfide river deposited sediments; characterise geochemically the waters in contact with sulfide-bearing river deposited sediments; map and monitor exposure areas and oxidation depth of deposited potentially acid forming (PAF) sediments; determine the depositional processes controlling sulfide distribution; and assess lag period, oxidation and metal release rates for the sediments. This work included the analysis of sediment and water samples collected on a 50 + 50 metre grid at six gravel/sand bars. The sediment samples were analysed for total sulfur, ANC, NAG, total sulfur and total copper. Water samples were tested for general water quality parameters, sulfate and a suite of dissolved metals including; Al, Ca, Cd, Cu, Fe-sol, K, Mg, Mn, Na, S and Zn. This paper presents the results of these investigations with particular emphasis on the geochemistry of the river sediments and associated contact waters.

Jan 1, 2003

By Edwards R

Greater efficiency of capture of minus 6 mm to fine micron size particles of free gold is achieved with the Knelson Concentrator. The development, principles of operation and recent innovations relating to this enhanced gravity concentrating device are described by the inventor, followed by a description of application and consequent economic benefits in low grade alluvial gold deposits by a large scale user of Knelson Concentrators in the Northern Territory of Australia.

Jan 1, 1990

By G Barla

In Europe, a major interest in the infrastructure and tunnelling fields is in the new crossings of Alps in the form of base tunnels, which are important components of the high-speed (for passengers)/high-capacity (for freight) Trans European railway corridors. These tunnels cross the mountain belt at the elevation of the main cities and basins located all around the Alps and are longer (up to 57 km) and deeper (up to 2500 m) than all tunnels constructed in the centuries before. The excavation of the first Alpine railway and road traffi c tunnels could in general be carried out successfully by conventional excavation methods. With the great lengths of the new base tunnels, mechanised excavation by using tunnel boring machines (TBMs) is imperative as it contributes significantly to savings in construction time and costs. Questions are however posed on the adoption of such a systematic tunnel construction method given the severe ground conditions which are some time anticipated along the tunnel alignment, with possible major geological hazards such as water inflow in heterogeneous fractured or karstifi ed rock masses, stress-induced tensile failure of hard rocks, and plastic shear failure and squeezing of weak rocks, etc. This lecture is to briefly review the current state-of-the-art in the understanding and modelling of two such critical hazards as spalling/bursting and squeezing ground behaviour. With the present interest in the design of mechanised tunnelling with TBMs in such conditions, the complex interaction between the rock mass, the tunnel machine and its system components, and the tunnel support is studied in detail by numerical modelling. The research and development efforts presently underway with the intention to provide the designer with a novel three-dimensional (3D) simulator of mechanised tunnel excavation are presented. Case examples are discussed with reference to the Lyon-Turin Base Tunnel design.

Mar 8, 2011

By D R. Seaman, R P. Tooher, B A. Seaman

"Several mine scheduling tools exist for use in optimising and scheduling the reserve according to in situ value. These tools generally value the ore on a per block basis according to regressed recovery models based on ore grade and type. It is then the task of the plant metallurgist to ensure that these ore blocks are fed to the plant in a manner that satisfies the prevailing plant constraints. This task is often completed in complex Excel® spreadsheets that are modified over time with factors applied to account for plant modifications or limitations.It is the authors’ experience that this approach is difficult to audit and replicate in a consistent manner. Furthermore, operational decisions, such as primary grind size or autoclave oxidation are made on the metallurgist or managements’ perceived optimum value and does not necessarily represent a cash flow based optimum.Many processing plants contain multiple internal constraints. As ore feed grades and properties change over the life-of-mine (LOM), processing-bottlenecks shift from one unit process to another and different operating strategies need to be adopted to maximise cash generation from the process.This paper presents a unified optimisation approach to scheduling ore based on a circuit mass balance to describe the process plant with individual models for each significant unit operation. The approach allows for optimisation over multiple input variables and the inclusion of linear and non-linear constraints.This optimisation process has been applied to different complex gold operations. The end result is an automated scheduler that selects the optimum blend of ores as well as plant operating conditions that satisfy all internal plant and shutdown constraints while maximising the objective of choice (metal production or cash flow). The models are also valuable for evaluating expansion or debottlenecking opportunities of individual processing units. These models are coded in Matlab® R2016a provided by MathWorks®, and can be deployed to end users in a compiled version with significant savings in time to run different scenarios over the Excel®-based systems.Citation:Seaman, D R, Tooher, R P and Seaman, B A, 2016. Optimisation of Complex Gold Processing Plants with Multiple Unit Operation Constraints - the Newcrest Planning Scheduler, in Proceedings 13th AusIMM Mill Operators’ Conference 2016, pp 191–198 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Oct 10, 2016

The research, development and testing of a Blast Control Plug (U.S. Pat. #4,754,705) funded by the U.S. Department of Energy is described. The plug's function is to improve blasting efficiency through the enhancement of stemming effectiveness and thereby reduce drilling and blasting costs. The plug comprises a solid unit placed in the blast hole within the stemming column above the explosive. It is designed for use with back filled drill cuttings or any other suitable material The research and development program comprised the testing of the plug in small diameter holes in competent rock for both bench and crater blasting configurations and full scale field trials in multiple hole and row blasts using blast holes of from 76 to 387 mm in diameter. Test measurements included stemming displacement and velocity, face movement and extent, peak air over pressure and ground surface peak particle velocity. Data acquisition equipment included a Spin Physics SP2000 high speed video motion analysis system, and acoustic and seismic monitoring units. Substantial reductions in stemming ejection velocity or ejection elimination were achieved whilst reducing stemming length by up to 35% over conventional practice. Peak air blast pressures were also reduced by between 8 and 25 dB. A strong inverse relationship between rock face movement and stemming ejection velocity was found. The implications of the importance of stemming effectiveness in blasting and computer blast simulation is also addressed.

Jan 1, 1990

By Grant JR, McKavanagh BM, Dear SJ

A geophysical technique of rock mass assessment for engineering purposes is being investigated and shows positive correlation with direct structural logging and mapping techniques for the detection of major geological features. The technique is cross-hole acoustic surveying incorporating high speed signal averaging, with a maximum hole separation in excess of 30 metres in hard unfractured rock masses. The bulk of the field test work was carried out in open stopes in the copper ore bodies of Mount Isa Mines Limited. The investigation forms part of an integrated study of blasting in mining, aiming for fragmentation control through blast design modification. The rock quality factor, Q, is presented as a blasting index and can be determined for a significant portion of a production stope.

Jan 1, 1981

By Patridge A. C

Hydrocyclones have widespread use as classifiers in applications such as mine fill preparation and coal preparation. A fundamental conflict often exists between recovery of all of the valuable material and maintaining the quality of the product. This conflict is a result of a portion of the feed material passing through the cyclone, effectively without undergoing any classification. This paper describes an investigation, undertaken as an undergraduate project in mining engineering at the University of NSW (Brook, 1994), into aspects of cyclones in which supplementary water injection is used in an attempt to reduce the amount of misplaced fine material reporting to the coarse product and hence improve the overall classification efficiency. In particular, the study concentrated on the effects of different modes of water injection. Two methods of introducing wash water into the cyclone body were investigated. A series of tests were performed on a laboratory hydrocyclone having provision for radial water injection at different levels through small orifices in the wall of the conical section, and a preliminary study was made of the performance of a novel cyclone in which the conical section had walls of a permeable polyethylene, permitting a uniform introduction of wash water over the entire surface.

Jan 1, 1995

The completion of the Hot Strip Mill at the Port Kembla works of Australian Iron & Steel Ltd., makes possible the production of steel plates and wide strip of a quality and in quantities not possible previously in Australia, and will also enable the production of tinplate to be undertaken in this country.The site chosen for the mill was a mud fiat underlain by a hard stone bottom at 5, to 801 feet below the surface; and a total area of one hundred acres was reclaimed to a level of 20 feet above the original surface.Three adjoining buildings were constructed to house the slab receiving yard, mill equipment and electric drive, together with the plate finishing line.After slabs have been heated to 2250°F at a rate of 90 tons per hour, they are transferred to the vertical scale breaker which is the first stand in the hot roughing mill. Here the primary furnace scale is first cracked and then blasted off by high velocity water descaling sprays.The next stand is the horizontal scale l;Jreaker, where any remaining primary scale is broken and then blasted off. After descaling, the slabs pass to the broadside mill, where short slabs are turned and rolled on broad side for wide plate.The next step is a slab squeezer which squares up the edges after broadsiding ready for the reversing mill. This is the finishing stand for plate and the last roughing stand for strip, which then passes to the finishing mill.The hot strip finishing mill consists of six stands with a maximum finishing speed of 2,230 feet per minute. Strip is cooled for coiling by water sprays on a hot run table and then coiled on a mandrel type downcoiler, from whence coils of hot strip are weighed and transferred by conveyor to the coil storage building.Plates are transferred from the reversing mill to the plate finishing line where operations consist of levelling, inspection, branding, cutting to width and length:INTRODUCTIONDue'to the increasing production of cars, refrigerators, washing machines and similar consumer goods in Australia, together with the increased requirements of galvanised iron...

Jan 1, 1956

By A D. Wulfse, C M. D Barton

Underground fractured aquifers in the Ernest Henry deposit are to a large extent controlled by deposit scale brittle structures. The underground mine has been subdivided into nine water zones based on hydrogeological characteristics, including conductivity and connectivity, within the mining areas bound by these structures. The nine water zones and the hydrological characteristics of the associated structures are utilised for risk assessing mine development and for targeting diamond drilling dewatering activities. Wireline and conventional underground diamond drilling techniques have been used throughout the network of underground aquifers with the aim of dewatering areas within the mining footprint. These dewatering drilling campaigns have historically been highly successful at lowering aquifer water levels throughout the underground workings. As part of recent mine expansion activities, diamond drilling has intersected high pressure (>507 psi), high temperature (>50°C) and high flow water (>3 L/sec) in as yet unconstrained underground aquifers. Groundwater is typically conducted through rubble and clay rich faults, further hampering progression of drilling. Drilling through fractured aquifers at depth presents both mine planning as well as safety challenges. Recent drill holes have been delayed or abandoned when aquifers hosting this high pressure, high flow water have been intersected, risking mine planning deadlines. Recent technological innovation developed to control groundwater outflows from the diamond drill hole whilst drilling has been trialled at the Ernest Henry Mine. This case study focuses on the utilisation of alternative drill methodologies to allow the current drilling campaign to continue without delay, whilst also improving safety conditions encountered on the drill site.

Mar 22, 2022

By E M. Wightman, C L. Evans

A recent survey of mineral processors undertaken as part of the International Mineral Processing Council (IMPC) Education Commission identified mineralogy as one of the key skills required for mineral processors (the other key areas being comminution, flotation, physical separation, sampling and extractive metallurgy). Past experience in a number of operations has shown what can be achieved when the data outputs from mineralogical tools are coupled with people with the right skills who can transform the data into actionable information. This paper reviews what has been done successfully in plant operations over a period of more than four decades and gives examples of a range of applications with both long and short-term objectives. The examples demonstrate the usefulness of mineralogical data – both basic and complex – in optimising mineral processing operations, whether the data are applied in a simple analysis or in more complex modelling. Similarly, the examples show the range of options available for operations to access the mineralogy information they need – through in-house experts and equipment based in centralised technology centres, through on-site equipment and experts or through external laboratories and consultants.The examples from industry highlight the huge potential benefit of including mineralogy as an integral part of operational best practice and raise the question of why more operations do not utilise what should be readily available data. Successful application of mineralogical data requires skilled people to generate relevant data of the required quality, together with skilled people to interpret the data (this may be the same person). And, as in any project, corporate recognition of the value of this approach to best practice is required to ensure continuing support. With fewer university courses providing courses in process mineralogy to undergraduate mineral processing engineers and chemical engineers, there is an increasing lack of knowledge about what mineralogical information is needed, how to get the required data and, equally importantly, how to turn the data into useful information.CITATION:Evans, C L and Wightman, E M, 2018. Understanding minerals in mineral processing – the basics and beyond, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 363–376 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By V Yadi

Geostatistics has been widely used for more than four decades as a powerful tool in ore resource/reserve estimates and grade control. This method has gradually replaced the conventional method such as polygon and cross-section for grade estimation by more mathematical techniques such as kriging. The advances in geostatistical understanding and the availability of appropriate software packages have given much more contribution in speed and high accuracy during production. However, in many cases, these techniques are sometime applied without support with a good thorough understanding of the geological controls on metal distribution. To produce the result close to actual, the geological control in interpretation and appropriate geostatistical task is a must. Geological logging was described in the core must be consistent with the level plan produced by commercial modelling software used as a guide for grade control during production. Experience gained through evaluation of the Central I deposit resulted that the most effective systems continue to be based on geostatistical methods of resource estimation. Computer applications modelling software packages are necessarily as the core of an efficient in undertaking these assignments. They contribute to make a valued to data management and are becoming increasingly effective during processing. The latter role is particularly important to check the actual versus estimated values where will significantly to improve personnel to have a confident with their knowledge combined with experience and complete their jobs satisfy.

Aug 22, 2011

By D Kubik, K The

The New Zealand (NZ) Transport Agency’s Waterview Connection will complete Auckland’s Western Ring Route, a 47 km north–south motorway alternative to Stage Highway 1. The project is being delivered by the Well-Connected Alliance comprising the New Zealand Transport Agency (NZTA), Fletcher Construction, McConnell Dowell Constructors, Obayashi Corporation, Parsons Brinckerhoff NZ, Beca Infrastructure and Tonkin & Taylor.The project involves construction of 5 km of new motorway, nearly half of it underground connecting State Highway 20 (SH20) to State Highway 16 (SH16). The underground portion of the project incorporates twin 13.2 m inside diameter (ID) tunnels 2.4 km long, each carrying three traffic lanes, one for north-bound traffic and one for south-bound traffic. The tunnels are being driven by a 14.46 m outside diameter (OD) 2400 t, tunnel boring machine (TBM) shield that was assembled and launched at the southern portal. It will be turned and re-launched at the northern portal for the return drive to the southern portal where it will be disassembled. This paper presents two major temporary works elements contributing to the successful launch of the TBM: the TBM assembly crane platform and the TBM shove frame and associated components.Tunnel boring machine shield assembly – crane platformThe TBM shield was delivered to site in subassemblies ranging in weight from 100 to 380 t. It was initially proposed to use a 750 t crawler crane sitting above the tunnel portal headwall to assemble and disassemble the TBM. However, this did not have sufficient capacity to allow the TBM shield to advance clear of the tunnel before disassembly commences. To reduce the crane’s working radius a temporary steel crane platform was developed that is supported on the side walls of the tunnel approach trench. This has enabled a smaller, less expensive, 600 t crawler crane to be used and will allow the TBM shield to clear the tunnel before disassembly.Tunnel boring machine launch – temporary worksTo launch the TBM a purpose built steel frame was required for the TBM thrust rams to react against. The shove frame had to be able to transfer the thrust loads from the TBM shield to the ground below and thrust wall behind. A range of potential thrust loads and jacking patterns were examined to develop the design load cases for the shove frame. The shove frame was used to launch the TBM at the southern portal and to re-launch it at the northern portal. Elements of the shove frame will also be used to support the portal faces during the TBM arrivals.CITATION:Kubik, D and The, K, 2014. Waterview Connection – temporary works for tunnel boring machine?launching, in Proceedings 15th Australasian Tunnelling Conference 2014, pp 281–288 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014