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By Pina P, Pereira MJ

The increasing exhaustion of raw materials entails the exploitation of poorer orebodies where the target mineral occurs frequently in a very fine dissemination. Consequently it is necessary to grind more and more fine to achieve an adequate mineral liberation. In other words, it is of fundamental importance to know what size one should grind in order to avoid the following detrimental situations: 1. Excessive grinding - giving rise to the generation of ultra-fine slime particles which may be lost in the ulterior concentration process and simultaneously leading to higher energy consumption. 2. Incomplete grinding - giving rise to insufficient liberation and consequently leading to considerable losses of the valuable components in the tailings. Although this issue constitutes one of the most important steps in mineral processing, little research has been done compared to other processes, mainly due to the fastidious experimental work required. This paper describes a complete and integrated system of image analysis, where some algorithms to determine automatically the degree of li beration, for different levels of grinding, are proposed. These algorithms, mainly based on mathematical morphology theory were tested with images obtained from polished sections of different grain size fractions. Cases studies on a complex sulphide ore from an important copper and tin deposit located in the South of Portugal are discussed. Samples of the unbroken ore are also studied by image analysis to predict the degree of liberation obtained according to the fineness of grinding.

Jan 1, 1993

By C Tapia Cortez, A G. Dempster, R Fradet, S Saydam, T de Roche, R Shishko, J Coulton

Human ventures into space are entering a new phase in which missions formerly driven by government agencies are now being replaced by those led by commercial enterprises – in launch, satellite deployment, resupply of the International Space Station and space tourism. In the not-too-distant future, commercial opportunities will also include the mining of asteroids, comets, the Moon and Mars. This research examines the role of off-Earth mining in a growing space economy. In this investigation, the term ‘mining’ is taken to embrace minerals, ice/water and other in situ resources. As the off-Earth mining initiative could be the engine that drives the space economy, it would be useful to understand what off-Earth mining market conditions and technology requirements are needed for that economy to prosper. These specific elements are studied in the wider context of creating an economy that could ultimately support a sustainable Mars colony. The methodology for developing the model focuses on the extraction of ice from the surface of Mars to produce propellant and water for life support for a possible colony.CITATION:Saydam, S, Shishko, R, Tapia Cortez, C, de Roche, T, Fradet, R, Coulton, J and Dempster, A G, 2015. An integrated economics model for in situ resource utilisation in support of a Mars colony, in Proceedings Third International Future Mining Conference, pp 305–312 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By M E. Trim, J J. Johnson, W Cranston

The Brightwater conveyance system is located near Seattle, Washington in the north-western United States. The East Contract portion of the system consists of a 4.3 km long, 5.9 m diameter tunnel in soft ground and two large shafts constructed in challenging soil conditions. The two shafts are situated side-by-side in an urban valley. One will house an influent structure to direct incoming sewage and outgoing treated effluent, while the other will house a 645 megalitre per day (ML/d) influent pump station. The tunnel contains four pipelines: two force mains to convey untreated wastewater eastward from the new pump station to a new treatment plant, one gravity-pressure pipeline to convey treated effluent westward to a new outfall in Puget Sound, and one high-pressure pipeline to convey reclaimed water from the treatment plant to downstream distribution points. The shafts and the tunnel presented many design challenges. Groundwater is near the surface in the area surrounding the shafts, and compressible peat and clay soils preclude dewatering during construction. These and other challenges were encountered during design of the pump station shaft and multiple-pipe tunnel. The challenges were addressed by a design that includes a dual intersecting circular cell shaft (referred to as æthe peanutÆ) and a single tunnel into which stacked pipes will be æstuffedÆ. This paper discusses the design approach and design details for both elements.

Jan 1, 2008

By M I. Pownceby, S P. Suthers, V Nunna, G J. Sparrow

Global demand for iron and steel has increased substantially over the past 20 years and there has been a greater focus on developing suitable processing options to treat low-grade hematite-goethite ores containing higher levels of silica and alumina impurities. The processing applicable to reduce the impurity levels in these lower-grade iron ores depends on their mineralogy and a thorough understanding of the process dynamics associated with the separation technology. Different separation technologies used to remove silica and alumina from low-grade iron ores were reviewed. The major concentration methods that may be applied to upgrade lower-grade lump iron ores include magnetic separation, wet and dry heavy media separation, and air-pulsed jigging. The technologies applicable to beneficiating iron ore fines include wet and dry gravity and magnetic separation, flotation, and roasting followed by magnetic separation. It is necessary to investigate the application of separation technologies on a case-by-case basis to select economically viable beneficiation strategies suitable for the particular low-grade iron ore. A commercial flow sheet is expected to involve the implementation of several separation technologies.

Nov 8, 2021

By P W. Cleary, G K. Robinson, M D. Sinnott

Discrete element modelling (DEM) is a research tool that involves numerically solving the equations of motion of large numbers of particles. It can be very useful for investigating mechanisms that can lead to bias when extracting samples from material as it is carried on a conveyor belt or as it falls from the end of a conveyor belt. DEM is more realistic than conceptual models and mathematical models; but it is not as realistic as physical experimentation. Its primary advantages over physical experimentation are that it is cheaper and that it allows many factors to be varied while keeping other factors unchanged.This paper reviews our investigations of the performance of sampling systems by using DEM. The sampling systems investigated include falling-stream cutters, cross-belt cutters, Vezins and a device called a ætrue-beltÆ cutter, which is being developed. The purpose of the review is to explain what DEM has contributed to the theory and practice of sampling, and to indicate what it is likely to be able to contribute in the future.CITATION:Robinson, G K, Cleary, P W and Sinnott, M D, 2012. How discrete element modelling is influencing the theory and practice of sampling, in Proceedings Sampling 2012 , pp 15-20 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 21, 2012

The homologous series of saturated fatty acids investigated in this study generally show a steady gradation of properties with chain length. The solution pKa values were assumed constant at 4.9, however reported pKa values could be lower or higher. Hematite flotation response and surface pressure for aqueous solutions of these fatty acids were measured as a function of pH. For the shorter chain fatty acids, the undissociated acid was shown to be the predominant surface active species with flotation, supplemented by the physical adsorption of acid anions as the chain length increased. The reduced solubility of the longer fatty acid carbon chains made these reagents ineffective as flotation agents. The maximum flotation response of hematite using tetradecanoic acid corresponded with the precipitation edge of the reagent. The results show that the values of surface pressure of the surfactants are not always a good indication of their effectiveness as flotation collectors.

Jan 1, 2005

By Koeng R, Richardson M, Hoare R

A discrete event computer simulation model was developed for two of the stoping methods currently used at the Z.C. Mines Broken Hill oper- ations. The objective in undertaking this project was to provide an effective tool for mine planning and design to allow comparisons of alternative extraction strategies and attempt to optimise the allocation of capital equipment and human resources. The Slam II simulation program was used in conjunction with ,a com- monly used data editor, text editor and graphics package to allow the simulation to be done on a personal computer with minimum training requirements. The computer hardware used was a portable computer cur- rently available using 80386/20MHz electronics. Specific logic techniques were developed to allow the Slam II language to simulate mining opera- tions because it was originally developed for manufacturing and com- mercial simulations. The design of the model was based on observations and a data collec- tion campaign. The model was designed with flexibility which allows simple editing of the input data which includes: - Insitu volumes - Development statistics -Loadout efficiencies -Loader speeds, availabilities and capacities -Chute numbers, volumes, distances and blockage statistics -Trucking statistics -Work schedules -Utility statistics

Jan 1, 1988

By D Gagnon, P Bouchard, F Vanier, E Soares de Lima Filho, J El-Haddad, M Sabsabi, G J. Wilkie, A Beauchesne, A Hamel, A Blouin, T Vaillancourt, F Boismenu, A Harhira, A Plugatyr, C Padioleau

Quantitative mineralogy is an established discipline in the geosciences and is aimed at providing mineral grade and texture information for geological and mineral processing applications. The two core technologies underpinning Quantitative Mineralogical Analysis (QMA) are Scanning Electron Microscopy (SEM) in combination with Energy-dispersive X-ray Spectroscopy (EDS). Technologies such as QEMSCAN and MLA are now routinely used to optimise the performance of large-scale mineral processing plants in the base and precious metal sectors. One of the major disadvantages of the QMA methods used today is extensive sample preparation requirements which make application of this technique to real-time mineralogical characterization not feasible. A breakthrough has been achieved by the National Research Council Canada in collaboration with CRC ORE by developing a novel Laser Induced Breakdown Spectroscopy (LIBS) based technology capable of real-time mineralogical characterization of process streams without sample preparation. The potential applications of this technology include, but not limited to, in-pit muck piles, underground draw points, cross-belt analysis as well as slurries. This paper describes the development of the LIBS-based technology from a proof-of-concept (TRL2) to the construction of a prototype sensor and its validation in a simulated environment (TRL5). Future work is being planned to test and further validate the LIBS sensor on a mine-site which will progress the technology to its next readiness level (TRL6).

Nov 10, 2020

By Mez W

the German ruining industry uses different residues for hackfilling and stowing. A hydraulic pipe conveying technology for these materials has shown advantages for the transportation into the mine. Pipeline conveying systems are able to bridge long distances, they save room within the underground workings and they save staff and costs. Absolutely necessary for successful use of the hydraulic conveying technology is the knowledge about the unusual non-Newtonian flow properties of solid/liquid mixtures like pastes and slurries. The flow resistance of these materials cannot be described easily by one viscosity. Owing to a yield point and a pseudo-plastic behaviour the viscosity changes with the shear rate and with the streaming velocity inside the pipe. Also these flow behaviours depend very sensitively on the liquid/solid-ratio, often so dramatically that gravimetric or volumetric dosing equipment is not in a position to control the production of backfill pastes. Quality changes of the solid raw materials (particle size distribution, density, mineralogical composition) lead to additional difficulties. The first experiences with hydraulic backfilling plants were troubled by plugged pipes. a bad backfill quality caused by unnecessarily high water content and high costs for chemical binders to solidify the backfill. The installation of viscosity controlled paste production leads to success with the hydraulic backfill technology. A development of the l)MT, a bypass pipe-viscometer, has been the key technology. The system is able to analyse on-line, difficult, sticky and abrasive substances and determine their non-Newtonian flow properties. Because the system measures real physical values it is in a position to pre-calculate process relevant parameters like the pressure drop of the backfilling paste in the conveying pipeline. Newer types of the viscometer system also measure the slurry density and calculate its composition. These systems have proven a success controlling backfill paste production plants. They offer it secure prevention of pipeline plugging and a production of high quality backfill pastes with a water content as low as possible.

Jan 1, 1998

By A K. B Opitz, M Becker, J L. Broadhurst

"One of the key drivers of geometallurgy is to define the ore characteristics and their variability to build a geometallurgical model. The inclusion of waste rock properties and their variability is just as important, given that the generation of acid rock drainage (ARD) poses one of the most significant environmental challenges facing the mining industry. Formed through the oxidation of sulfide minerals in the presence of oxygen and water, ARD generation is exacerbated through the regeneration of lixiviates by naturally occurring iron- and sulfur-oxidising micro-organisms. In order to manage the potential risk of ARD pollution, timely, accurate, reliable and robust characterisation and prediction of the ARD potential of waste material is critical from an early stage in the mining process.This study demonstrates the use of the biokinetic-accelerated weathering test developed at the University of Cape Town to characterise the ARD potentials of gold waste rock samples under microbial conditions. These tests are performed in conjunction with standard characterisation tests to provide an indication of the potential for ARD generation under both chemical and biological conditions. Results provided information regarding the relative rates of acid neutralisation and acid generation, with the contribution of specific minerals to the observed behaviour considered through use of a detailed mineralogical assessment. Overall, the addition of the biokinetic test to the current geometallurgical characterisation and prediction toolbox will allow for relatively rapid assessment of the bulk kinetics of ARD generation.CITATION:Opitz, A K B, Becker, M, Broadhurst, J L, Bradshaw, D J and Harrison, S T L, 2016. The Biokinetic Test as a Geometallurgical Indicator for Acid Rock Drainage Potentials, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 183–192 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By M G. Shaw, M A. Rhamdhani, S P. Singh, A R. Duffy, B Eisenbart, A K. Shukla, G A. Brooks

The field of astrometallurgy is a growing area of study. Metal production on the Moon is likely to begin in less than a decade as major space agencies such as NASA (National Aeronautics and Space Administration) and CNSA (China National Space Administration) are preparing to construct permanent lunar bases. The utilisation of regolith to generate oxygen and metals is expected to be important in the development of a sustainable lunar habitat. This paper provides an overview of potential metallurgical processing methods for lunar conditions, emphasising the impact of lunar factors on slag chemistry. The interaction between regolith and the extracted metals, as well as their impact on slag composition and refractory performance, are critical considerations in metal production on the lunar surface. The initial research on lunar metallurgical technologies is focused on oxygen extraction and Fe-Si alloys are reported as the by-products of these processes. This paper delves into the fundamental thermodynamics associated with the carbothermic reduction of lunar regolith. Thermodynamic analysis using the FactSage™ ver 8.2 software package indicates that the Fe-Si alloy can be produced as a metallic product from the lunar regolith at temperatures ranging from 1400°C to 1600°C under terrestrial conditions. However, under ultra-high vacuum conditions (3 × 10-15 bar) on the Moon, the required operating temperature for producing ferrosilicon would be significantly reduced. Thermodynamic modelling results indicate that under lunar vacuum conditions, Fe-Si alloys only exist as solid phases at lower temperatures below 650°C. At higher temperatures, both Fe and Si are expected to be present in the gas phase. In this work, the carbothermic reduction of the Lunar Mare Simulant (LMS-1) is conducted under terrestrial conditions. The findings indicate that the process can readily yield Fe-Si alloys with 7–10 wt per cent Si at 1600°C. Additionally, energy dispersive spectroscopy (EDS) analysis of the resulting Fe-Si alloy indicates the presence of phosphorus up to 1 wt per cent.

Aug 21, 2024

By M W. N Buxton, M S. Shishvan, J Benndorf

The flow of information, and consequently the decision-making along the chain of mining from exploration to beneficiation, typically occurs in a discontinuous fashion over long timespans. In addition, due to the uncertain nature of the knowledge about deposits and the inherent spatial distribution of material characteristics, actual production performance in terms of produced ore grades and quantity and extraction process efficiency often deviate from expectations. Reconciliation exercises to adjust mineral reserve models and planning assumptions are performed with timely lags of weeks, months or even years.With the development of modern information and communication technology over the last decade, a flood of data about different aspects of the production process is available in a real-time manner. For example, sensor technology enables online characterisation of geochemical, mineralogical and physical material characteristics on conveyor belts or at working faces. The ability to utilise this additional information and feed it back into reserve block models and planning assumptions opens up new opportunities to continuously control the decisions made in production planning to increase resource recovery and process efficiency. This leads to a change in paradigm from a discontinuous method to near real-time reserve reconciliation and model updating, which calls for suitable modelling and optimisation methodologies to quantify prior knowledge in the reserve model, process and integrate information from different sensor sources, back propagate the gain in information into reserve models and efficiently optimise operational decisions in real-time.This paper introduces the concept of an integrated closed-loop framework for real-time reserve management, incorporating sensor-based material characterisation, geostatistical modelling under uncertainty, modern data assimilation methods for sequential model updating and mining system simulation and optimisation. The effectiveness of the framework and the value added will be demonstrated in an illustrative case study.CITATION:Benndorf, J, Buxton, M W N and Shishvan, M S, 2014. Sensor-based real-time resource model reconciliation for improved mine production control – a conceptual framework, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014, pp 223–234 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

By J M. Galvin

The traditional engineering approach to assessing stability is based on comparing resisting force (capacity) to driving force (demand), or strength to working stress. In underground coal geomechanics, considerable effort has been expended on quantifying the strength of rock structures. However, this has not been matched by advances in determining the load acting on these structures, reflecting a reluctance by some to embrace numerical modelling to assess load magnitudes and distributions. Numerical modelling is a valuable aid as loading environments are a function of both the stiffness of the mine workings and the stiffness of the superincumbent strata and are statically indeterminate in most cases.This paper defines stiffness, which is often confused with elastic modulus. It shows that, effectively, stiffness encapsulates geology, depth of mining, panel width, pillar width and mining height. Therefore, these factors are variables that need to be taken into account when determining stress magnitudes and distributions about mine workings. A range of examples are presented that illustrate the significance of the stiffness of the superincumbent strata on surface subsidence; the magnitude and distribution of pillar and abutment load; and aspects of bord and pillar mining, pillar extraction and longwall mining. These examples provide bases for identifying the limitations of some empirical approaches to mine design, identifying how to compensate for some of these in design processes; and emphasising the need to make greater use of numerical modelling in understanding and quantifying loading environments in underground coal mining.CITATION:Galvin, J M, 2014. The significance of superincumbent strata stiffness and its impacts on coalmine design, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference , pp 3–16 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 5, 2014

By D J Williams

Coal washery wastes comprise tailings, finer than 0.5 to 0.1 inn depending on the sophistication of the washery, and coarse reject, typically finer than 50 mm. Subaerial disposal of coal tailings slurry at about 30 per cent solids by mass results in the formation of a delta with an average slope of about 1 in 100, representing one extreme. The ravelling of coarse reject on loose-dumping, results in an angle of repose slope with an angle of about 37" (1 in 1.3), representing the other extreme. The pumped co-disposal of coal tailings and coarse reject results in the formation of an upper delta with an average slope of about to one in ten, between the two extremes. The depositional behaviour of these three waste streams is discussed and compared in this paper. The important depositional and material parameters, and a theoretical description of the processes involved, are also presented. Comparisons are made between the depositional behaviour of the various coal washery waste streams, and natural depositional systems, such as rivers, alluvial fans, and scree slopes.

Jan 1, 1998

By S Hancock, B H. Brady, H Muhlhaus

The aims of this paper are to present the governing science, verify the performance and demonstrate the potential engineering applications of a computational simulator for in situ leach mining of non-ferrous minerals. Assuming that the target mineral is deposited either uniformly within rock matrixes (matrix-hosted) or on fracture walls (fracture-hosted), in situ leaching can be treated as reactive flow and transport in geological media (porous media for matrix-hosted ore deposits and fractured media for fracture-hosted ore deposits). Under this treatment, the processes of in situ leach mining for non-ferrous minerals can be quantified through several sets of equations and these coupled equations have been numerically solved. The computational simulator has been applied to the simulations of one-, two-, and three-dimensional in situ leaching cases. The computational simulator, together with laboratory and in situ leaching tests, can be used to:optimise the leaching chemistry; optimise the in situ scale mining operations; scale up the in situ scale test operation to a full-scale mining operation; and evaluate the post-mining environmental restoration plan.

Jan 1, 2000

By M Henderson, M Hudyma

Mining-induced seismicity at Junction Gold Mine became a serious operational problem in the late-1990s. Assessing the local seismic hazard is an important step in assessing the risk associated with potential rockbursting. This paper discusses the qualitative and quantitative means of assessing seismic hazard used at Junction. In qualitative hazard assessment, the role of the primary factors contributing to mining-induced seismicity and rockbursting are identified. These factors include: rock mass properties, geological structures, mine development, and stoping. A qualitative seismic hazard map has been developed considering these factors. In quantitative hazard assessment, seismic source parameters from an Integrated Seismic System are used to assess seismic hazard. The seismic source parameters found to be relevant to seismic hazard assessment at Junction are discussed.

Jan 1, 2002

By G T. Hefter, P Singh

The effect of using SO2 as an anodic depolariser in the electrowinning of copper from aqueous acid sulphate solutions has been studied using cells without/with a ceramic diaphragm. In all cases SO2-saturation of the electrolyte/anolyte decreased the anode potential by 68 to 75 per cent largely due to a change in the anode reaction from the oxidation of water to the oxidation of SO2 . However, poor quality deposits and low current efficiencies are encountered if SO2 is allowed free-access to the copper being deposited at the cathode. This situation is easily avoided by using a diaphragm to restrict SO2 to the anode compartment and for these conditions the resultant copper deposits are of a similar (high) quality to those obtained in the absence of SO2.

Jan 1, 1999

In May 1977 a new dam was commissioned for disposal of 600,000 metric tonnes/year of tailings. Design basis, costs and construction problems are described. Problems arose, assoc- iated with lack of experience in building such a dam "from scratch". Solutions are described land costs given.

Jan 1, 1978

By D Matthews

Increases in mining and production capacities can have a major impact on the productivity of a mining and production facility during the construction and commissioning period. With minimised production loss in mind, a multi-phase modular plant design was implemented on the Khumani Mine in the Northern Cape, South Africa. The first phase involved a run-of-mine (ROM) crushing facility and the subsequent modular processing facility with capacity for 8.4 million tons per annum (Mt/a) product. An interim phase comprising modular additions to the processing facility increased capacity to 10 Mt/a product, with tie-ins occurring during maintenance periods. The second phase involves a second ROM crushing facility and modular additions to the processing facility, increasing capacity to 16 Mt/a product. This paper outlines the design considerations and limitations with modular design that need to be considered and shows how effectively construction and commissioning were implemented within shut-down and maintenance periods.

Jul 11, 2011

Hidden under picturesque Bemic Lake, in Canada's eastern Manitoba, lies a highly fractionated pegmatite orebody, hosting a unique assemblage of minerals. Accidentally discovered in 1929, the orebody had a brief history as a tin producer, but it is now mined by Tantalum Mining Corporation of Canada, Ltd. (TANCO), for its cesium, lithium, rubidium and tantalum bearing minerals. The mine also has potential for mbidium-feldspar, amblygonite, gallium rich mica, and quartz production. This paper describes the geology of the orebody, and its mining and processing. Selective, concurrent, mining and milling of the various products necessitates a high degree of planning and control, and these aspects are also discussed. The introduction of Quality Control and SPC are discussed, for such are the keys to excellence.

Jan 1, 1989