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By R J. Thompson

In truck-based hauling systems, the mine haul road network is a critical and vital component of the production process. As such, underperformance of a haul road will impact immediately on mine productivity and costs. Operations safety, productivity and equipment longevity are all dependent on well-designed, constructed and maintained haul roads. With the advent of autonomous haul trucks, the haul road itself becomes all the more critical to the success of these type of operations; not only in relation to mine operators requirements for safer and more efficient and predictable haulage systems, but also in response to autonomous truck manufacturers’ requirements for a more predictable and controlled operating environment. This paper presents a brief summary of the state-of-the-art in surface mine road design and then proceeds to examine the design and technological challenges associated providing a safe, predictable and affordable road for autonomous mine haul trucks. The paper serves as a basis for evaluating the contributions that enhancements in road design and management can deliver to autonomous mining operations, an initiative that also has scope for adoption within the operating life of many mines, haul roads and haul trucks.

Nov 22, 2011

By G J. Lyman

Sampling of grain for mycotoxins is challenging in that some mycotoxins, such as Ochratoxin A (OTA), have very low permitted levels and the kernels carrying the mycotoxin may be highly localised within the bulk of the grain as ‘hot spots’. Sampling for genetically modified organisms (GMOs) can be fraught with similar problems, especially if the contamination is adventitious and random. Incremental sampling under these circumstances can be shown to lead to a high variance in the sampling result.A new design of sampler for grain and other free-flowing particulates has been developed that is effective in practically eliminating the sampling variance due to distributional heterogeneity (DH).This paper introduces the design and argues that the sampler should be free of sampling variance due to DH.CITATION:Lyman, G J, 2017. A new sampler for grain and other free-flowing particulates, in Proceedings Eighth World Conference on Sampling and Blending , pp 277–280 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By P Ramsaywok

The use of saline water for mineral beneficiation in arid regions is general practice and also the case with Exxaro Namakwa Sands, situated on the west coast of South Africa. Although it is ‘cost effective’ to use sea water for mineral beneficiation, downstream process separation efficiencies may be negatively affected. This is more specific to surface dependent separation techniques such as electrostatic and high tension (HT) separation. If minimal fresh water is available then, proper washing is often neglected. Salt crystals can form on particle surfaces during the drying process before electrostatic separation.This paper describes a study that has been conducted to determine the effect of upfront salt water processing on downstream electrostatic/HT separation. The study indicated that minor quantities of salt can cause the separation efficiency to decrease substantially.

Oct 5, 2011

By Kavanagh M. E, Henley R. W

The Meekatharra mining district lies in the northern pan of the Murchison Province of the Archaean Ynlgam block of Western Australia. Since dis- covery of the Paddy's Flat belt in the district in 1897 total gold production has been 67 tonnes and a further 33 tonnes in resources have been defined by drilling. The Paddy's Flat gold deposits occur within the Gabanintha Formation, a basal formation of the Murchison greenstone sequence containing komatiitic basalts, ultramafics and minor banded iron formations. The regional control on the distribution of deposits is an anastomosing shear belt which extends over 350 km and incorporates the Mt Magnet, Reedys and Meekatharra deposits. The following gold deposit styles may be recognized based on lithological association and alteration: Albite porphyry hosted, Carbonate-fuchsite- quartz alteration hosted deposits, Banded Iron Formation hosted sulphide replacement gold deposits and quartz vein deposits. With the exception of the banded iron formation hosted deposits, the Paddy's Flat alteration zone shows strong similarities to the alteration styles at Kerr-Addison (Ontario).

Jan 1, 1991

During operations, mining and metallurgical processes may generate effluents such as tailings water, acid mine drainage (AMD) and seepage and process acid streams. Depending on the type of ore and the metallurgical process, these effluents may contain one or more toxic compounds (eg acidity or alkalinity, cyanide, ammonia and/or nitrate, heavy metals, total suspended solids (TSS), sulfate) in elevated concentrations requiring treatment before their discharge to the environment or recycle/reuse in the process. Natural oxidation of sulfide minerals present in mining wastes (eg tailings and waste rock) at mining sites may generate AMD, which is characterised as a low pH, high acidity effluent containing heavy metals and sulfate. If generation of AMD cannot be controlled and/or prevented, AMD needs to be collected and treated for neutralisation of acidity and reduction of metals and TSS to meet regulated water quality standards. It is important to note that some of these compounds may persist in run-off from mine sites, even after the mine and processing facilities are decommissioned. Treatment of mining and metallurgical process effluents can be accomplished by means of various physical, chemical and/or biological methods. The mode of process application may vary from the use of either specifically designed, controlled and automated facilities or passive systems. Lime neutralisation and precipitation is the most common method used in the mining industry to treat AMD. To reduce the problems associated with disposal and long-term storage of the resulting sludge, the use of a high-density sludge process (HDS) has become a preferred option. The use of other chemical reagents, waste or by-products from other industries, and biological sulfate reduction methods can also be considered as viable options for site-specific situations. Recently, several passive treatment systems have been designed and successfully operated, even in the cold North American climate. This paper will discuss available options and provide insights for selecting a suitable method for a given situation using case studies from projects conducted by Golder Associates around the world over the last decade.

Jan 1, 2006

By Z Lianbi, Z Yibin, Z Youhong, P Bin

Without adequate soil available, it is difficult to rehabilitate a large area of acid mine waste dump with sustainable plant communities, which has a strong potential acid generation. In the present project, paste tailings capping method has been put forward to reconstruct plant ecosystem on acid mine waste rock dump. This rehabilitation method uses paste tailings as capillary break and plant growth media. The tailings used contained 26.3 per cent of particles of less than 20 ¦m which satisfy the requirement of grain of paste tailings preparation. The tailings are not acid- producing materials. In addition to Cu, total contents of Zn, Pb, Cr, Cd, As and Ni in tailings are lower than those in local soil. Paste tailings concentration 70 per cent ~ 72 per cent was prepared by concentrating ten per cent tailings by using polypropylenecrylic sodium as flocculation. The potential pollution risks are low by using paste tailings as capillary break layer. Plants directly grown in the tailings did not particularly accumulate Cu, Zn, Pb, Cr, Cd, As, Ni in roots, stem and leaves, which were 0.01 ~ 1.6 times of those grown in soil.CITATION:Yibin, Z, Lianbi, Z, Bin, P and Youhong, Z, 2012. Study on paste tailings capping ecology reclamation on acid mine waste rock dump, in Proceedings Life-of-Mine 2012 , pp 243-246 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By Shepherd J

Megascopic and microscopic studies of cleats and mining induced cleavage in Ihe first workings at Leichhardt Colliery reveal the presence of four distinct fracture sets. Microscopic studies confirm underground observations of the fracture sets.The most likely order of formation of the fractures is (i) "butt" cleats (ii) facc cleats (iii) shallow dipping faults (iv) mining induced cleavage. Three fracture sets apparently formed by tensiIe failure. Microscopy shows that the mining induced cleavage surfaces have preferred starting or lerminating points at the extremity of a "butt" cleat and a vitrite-dull coal band boundary. It is postulated that the induced cleavage begins at 'butt' cleats which behave as Griffith flaws under high compression around Leichhardt Colliery faces. Instantaneous outbursts of coal and gas are associated with only those workings which are affected by mining induced cleavage and occur at or adjacent to working faces.

Jan 1, 1981

By P J. Hawke

Within the Mesa J pisolitic iron ore mine, clay is distributed unevenly throughout the deposit and often forms as pods and channels less than 10 m in width. The mine resource model, based on 50 m + 50 m spaced drilling, has been unable to accurately delineate the clay for scheduling and mining purposes. Therefore, alternative methods for mapping the clay-contaminated ore were sought. Predictive clay mapping will significantly reduce production costs at Mesa J through improved selective mining practices, more accurate scheduling, reduced wear on mining equipment and minimising the need for maintenance of haul roads and ramps. High lateral resolution electromagnetic (EM) surveying using a Geonics EM31 instrument can quickly and inexpensively delineate the extent and orientation of the clays. Preliminary results indicate that a block model based on the interpretation of the EM data can accurately predict the distribution, volume and tonnage of ore and waste material. While rip-line mapping, infill drilling, ground penetrating radar and gravity can delineate clay with various degrees of success, none were as efficient as EM31.

Jan 1, 2002

By D Feng, G C. Lukey, J S. J, R R. Dagastine

An ongoing challenge in the coal industry is pyrite removal using the flotation method for fine particles. The use of a æseparation in frothÆ (SIF) technique to recover coarse particles of up to a few millimetres in size has presented a potential solution. However the commercial success of SIF is still limited due to the poor understanding of the separation mechanism. The particle floatability in SIF is determined by the constructive or destructive stresses resulting from the forces exerted by the particle on the bubble films. Hence, the surfactant properties and the mineral characteristics (eg hydrophobicity, shape, etc) are the key factors that control the interaction between the particle and froth. In the present work, the interaction forces between different particles (ie crushed glass, pyrite and coal) and a single air bubble are measured in a non-ionic surfactant solution (pentaethylene glycol mono n-dodecyl ether, C12E5) using an atomic force microscope (AFM). Experimental results show that the interaction is primarily dependent on the contact angle (ie the degree of hydrophobicity of the minerals). For crushed glass, the transition from repulsion to attraction was observed as the contact angle increased. As the concentration of C12E5 increased, the adhesion force was suppressed due to wrapping effect. For coal and pyrite with much higher hydrophobicity, long-range attraction was observed. The effect of shape factor was only visible at high surfactant coverage where sign of destabilisation became noticeable on the retracting force curve. These results provide a fundamental understanding of the direct interaction forces of a complex real system between an irregular particle of either crushed glass, pyrite or coal and a single air bubble. Theories developed for interpretation and modelling are thus far based upon the study of ideal systems of glass or polystyrene spheres and an air bubble and were incapable of explaining the interactions in complex real systems. The presented measurements were a first approach to the problem of real mineral-bubble interaction in flotation systems. Thus, the results can only best be interpreted semi-quantitatively.

Jan 1, 2005

By X Ma

Kaolinite is of very fine particle size in nature and thus its dispersion plays a key role in the successful removal of kaolinite in iron ore flotation and selective flocculation processes. As the most widely used dispersant in the world, sodium silicate has been used as a standard dispersant for kaolinite in the iron ore industry. However, the actual effect of sodium silicate on the colloid stability of kaolinite particles and its dispersion mechanism remain unknown in the literature. In this work, the dispersion effect and dispersion mechanisms of some common inorganic and organic dispersants, including sodium silicate, polyphosphate and a low molecular weight polyacrylic acid, on kaolinite particles were systematically investigated through electrophoretic mobility and colloidal stability studies over a wide pH range. It was found that sodium silicate-kaolinite interactions only take place in the neutral and acidic pH range, while polyacrylic acid and polyphosphate interact with kaolinite from pH 3 to 10.5. Consequently, sodium silicate only disperses kaolinite at neutral and acidic pH. In contrast, polyacrylic acid and polyphosphate disperse kaolinite from pH 3 to 10.5, with strong dispersion effect observed at neutral and acidic pH. In the iron ore industry, selective fl occulation and reverse cationic fl otation, the most widely used flotation route, are both conducted at pH 10 to 10.5. The results of the present study show that, at such high pH, polyacrylic acid and polyphosphate are more effective dispersants of kaolinite, in comparison with sodium silicate.

Jul 11, 2011

By Parker A. J, Grimsey E. J

Studies have been carried out on the dead roasting of a copper-iron and a copper-nickel-iron sulfide concentrate, followed by segregation roasting with coal and leaching with either curpric sulfate in aqueous acetonitrile or cupric chloride in brine solution to preferentially solubilize copper. The effect of dead roasting and segregation roasting conditions on the overall leaching of copper and the separation of copper from iron and iron and nickel is reported. An excellent separation of copper from iron and a good separation of copper from iron and nickel can be obtained provided sulfur is removed to 0.5 per cent or less during the dead roast and provided the coal addition and temperature of the segregation roast are near the minima required for the segregation of copper.

Jan 1, 1983

By I Elias, E Moya, S Chaffer

This paper is based on a case study from a mine site that operates two gyratory primary crushers. These crushers were encountering problems, which included inconsistent P80, reduced liner life tonnage and, on some occasions, catastrophic failure of the liners.As part of an evaluation process, both crushers were ‘mapped’ using a technology for condition monitoring and modelling of the crusher’s wear components. The technology provides comprehensive coverage of the crusher’s concaves and mantle at 100 mm intervals. It also automatically assesses wear rate between inspections and determines the highest wear areas. Outcomes include projected optimum reline dates at target replacement thicknesses, the identification of asymmetrical wear patterns, and the accurate measurement of open and closed (OSS/CSS) side settings.A comprehensive study was performed to optimise the performance of both these crushers at site. Over a period of seven liner service lives, the strategies to improved performance included liner analysis (concaves and mantle profile analysis), tonnes per day (t/d) and tonnes per hour (t/h) analysis, mantle reutilisation, detection and control of loose concaves, and detection and control of uneven wear and hot spots.These strategies resulted in the improved mechanical and operational performance of both crushers through concave and mantle redesign, OSS/CSS control, accurate wear forecasting plus other initiatives.As a result of these initiatives, the site now experiences benefits which include consistent product size, increased tonnes per hour (t/h) for both crushers and the liner life tonnage has doubled. Additionally, further benefits include less downtime for crusher liner maintenance and the reduced cost of inventories by mantle reutilisation.CITATION:Elias, I, Chaffer, S and Moya, E, 2015. Improvements in service life and cost reduction for gyratory primary crushers through mantle and concaves optimisation – a case study, in Proceedings Iron Ore 2015, pp 115–128 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By Akerkar D. D, Dey M. L, Mathur S. B, Chowdhury S. K R

The extraction of gold and silver from chalcopyrite concentrates has been investigated. In view of the recent interest in non-cyanide leachants for gold and silver, one such alternative reagent, namely thiourea, has been employed in the present work. Precious metal leaching was attempted from received copper concentrates as well as pre-oxidised concentrates. Pre-oxidation of the concentrates was carried out by three different methods, namely roasting, pressure oxidation and biological oxidation. After pre-oxidation and leaching of the base metals, the leach residues were subjected to further leaching for precious metal extraction. The results obtained on the extraction of gold and silver from received concentrates as well as pre-oxidised concentrates are presented and the effectiveness of the three pre-oxidation routes employed is compared.

Jan 1, 1992

By K Banerjee, C Dube

Veolia Water Technologies was contracted by a global coal mining company to design a retrofit acid mine drainage treatment facility using DenseSludge™ technology on a former coal refuse disposal site. The project constraint was to reuse current facilities in order to reduce additional capital work cost and avoid additional footprint requirements while improving treatment performance and reducing sludge production and chemical consumption. The initial installation of 454 m3/h served as a pilot plant to demonstrate the benefits of the process and ultimately provided design criteria for the new facility. The pilot demonstrated the benefit of the technology by reducing sludge volume by 90 per cent compared to conventional processes currently in use. The sludge that is reinjected into the mine contains less water, which reduces the volume of water that returns to the mine pool for treatment and mine water balance. Furthermore, the pilot plant reduced lime usage compared to conventional processes by operating at a lower pH set point, demonstrating steady pH control and stoichiometric lime utilisation.CITATION:Dube, C and Banerjee, K, 2015. Sludge conditioning technology to reduce sludge and the cost of acid mine drainage treatment, in Proceedings Tailings and Mine Waste Management for the 21st Century , pp 105–110 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 27, 2015

By H Zhang, S Li, J Song, Z Lv

In this paper, a method for extracting and refining metallic molybdenum using low-temperature ZnCl2- NaCl-KCl molten salt was proposed. The electrochemical behaviour of molybdenum ions in ZnCl2- NaCl-KCl molten salt was investigated in detail, and pure metallic molybdenum was collected on the cathode. The reduction and diffusion processes of Mo(V) ions in ZnCl2-NaCl-KCl molten salt were determined through a series of electrochemical methods. The diffusion coefficients and nucleation modes of Mo(V) ions were also studied, and electrolysis was conducted for a prolonged period at a constant current density. The results indicated that the electrode reduction of Mo(V) ions in ZnCl2- NaCl-KCl molten salt proceeds through a three-step reaction: Mo(V) → Mo(IV) → Mo(III) → Mo at 250°C. The Mo(V) → Mo(IV) reaction was reversible and diffusion-controlled, with a Mo(V) diffusion coefficient of 6.02 × 10-6 cm2 s-1. Additionally, the nucleation mode of Mo(V) ions was instantaneous nucleation. The products electro-deposited were confirmed of metallic molybdenum with a particle size of less than 1 μm.

Aug 21, 2024

By S Jeffrey, S Mundell, F Arboleda

In the current cycle of low commodity prices and rising costs, mine managers continue to focus on optimising mine performance and productivity. A critical component of strengthening performance and productivity is ensuring material is routed correctly and efficiently through the core mine production activities of drilling, blasting and grade control.By the time a blast is planned, an enormous amount of intellectual property has been invested in the exploration, resource development, feasibility studies and mine planning activities. The value of that knowledge is either realised or diminished during mine production. Efficient execution of the process is critical and is reflected by the quality and timeliness of the information produced.Multiple teams are involved in the mining extraction process. These teams are all under time pressure to keep the mine equipment operating. One of the root causes of this pressure is the dependency between the teams. They do not operate in isolation, but are a link in a chain depending on the outcomes of each activity. It is essential communication is efficient so tasks can be completed according to the production schedule. Unfortunately, communication fails when unintegrated systems are used because of:- different teams seeing different data, hence there is not an overall, up-to-date view of progress and priorities- lack of cross-functional visibility of data leading to failure to identify errors in time to address or correct issues- teams tending to be siloed and focusing on their part of the process rather than the overall objective.With different systems used for the parts of a common goal, supervisors and managers lack visibility of the process. This makes it difficult to identify process improvement opportunities.Streamlined communications help consolidate all data and activities resulting in improved cooperation between mine production teams. This outcome increases the confidence and efficiency of material routing decisions. It also reduces potential impact to mine performance from errors in early stage tasks like drilling and grade control. Having everyone collaborating off the same trusted data, helps teams identify with common goals and find business improvement opportunities as they appear.CITATION:Arboleda, F, Mundell, S and Jeffrey, S, 2016. Driving mine performance through communication, in Proceedings International Mine Management Conference, pp 117-124 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 22, 2016

By B Twidle, D Bertoldi, J Meikle, R Dunne

The Waihi Gold Mine is situated in a high rainfall area (annual average of over 2 m) on the North Island of New Zealand. Water treatment and discharge at the mine has been ongoing for the last 25 years. The first water treatment plant consisted of a æstandardÆ water treatment facility (ferric chloride precipitation) and cyanide detoxification. With time the project has expanded and the volumes of water increased requiring additional treatment methods (reverse osmosis) to meet the water quality for discharge. This paper will provide information on the historical development of the water treatment flow sheets, performance data and operating costs.CITATION:Bertoldi, D, Dunne, R, Twidle, B and Meikle, J, 2013. Water treatment at the Waihi Gold Mine, in Proceedings World Gold 2013 , pp 503-508 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

By E L. Kotova

Completeness of extraction of a mineral from ore depends on many reasons. First of all it is a function of quality of disintegration of ore. It is supposed that two basic factors: character of structure and texture of the ore aggregate and a disintegration technique influence the quality of the mineral aggregate destruction, æopeningÆ of its internal boundaries. In this paper, the problem of technological mineralogy from the point of view of genesis of the mineral aggregate, its typomorphical features and methods of their quantitative description are discussed. The purpose of this research is to provide information for technologists. It should enable the development of a rational flexible scheme of disintegration of ore with full extraction of a useful component, without its losses and without unnecessary expenses of energy. For achievement of this purpose the mineralogical information should have ½number and a measure+. By the authors, the technique of the quantitative analysis of fabric of the mineral aggregate based on several models û thermodynamic, crystallographic and geometrical is offered and discussed. The leading role in the quantitative analysis of a fabric of ore belongs to internal bounders. But internal bounders of the mineral aggregate by bounders or faces of the mineral individuals or mineral grains are formed. Their geometry, orientation concerning own (mineral grain) crystallographic lattices, orientation and distribution in space of the ore aggregate are proportional to the energy accumulated at origin and the further growth. These characteristics of mineral individuals are consequences of conditions of their formation. That is why the named triad of models is used. From crystallography it is known that faces of different stability and mobility form borders of crystals. They also contain different quantity of energy. Mineral grains also are faceted by different energy borders. They form intergrowths with each other according to a principle of balance or unbalance. That is why in addition to traditional parameters of the description of a fabric of the mineral aggregate (mode and grainmetrical composition) it is necessary to add new. For example, length and the square of intergrowthing bounders of mineral individuals differentiated (in couples), crystallographic symbols of borders, their roughness and so forth. Consequently, solving a problem of the geometrical characteristic of borders, we define also its power characteristic. In this paper experience of application of our technology in studying ores of one of deposits of Urals Mountains is presented. For realisation of these types of the analysis technologies of measurement, the program of calculation and the devices, which are carrying out the analysis in a semi-automatic mode, are possessed. Structure and texture of rock or ore aggregate reflect its formation and transformation conditions. It is important to understand that disintegration energy cannot be more than aggregation energy, the energy of intergrowths formation. The square and orientation of mineral individuals borders vary at pressures or stresses of mineral aggregate evolution. These phenomena often cause selective increase in the square of borders at constant average grain size, ie the granulation. Granulation presents the increase in quantity of mineral individuals while their modal share remains constant. At the same time their average mineral grains size. Some mineral individuals increase in size at increased pressure. When lithostatic or lateral pressure drops the majority of mineral grains increases in volume at the cost of intersticial or film solutions or fine grains. These are only special examples of the ontogenesis of the mineral aggregate. They illustrate our statement that all changes in fabric of the mineral aggregate are a reaction on varying external (ie geological) conditions. It is possible to consider that structurisation of totality of mineral individuals as a whole is a process of adaptation of the mineral aggregate, which forms and exists in varying force and energy fields. Differential and integrated geometry of total internal boundaries of the mineral aggregate serves as adaptation mechanism of the mineral grains system. Boundaries form intergrowths of the mineral aggregate. Thus, it is possible to consider that the most informative parameters of the stereometric analysis for restoration of the ontogenesis of the mineral aggregate are the following. First of all, it is a quantitative estimation of the volumetric shape of the ore mineral in crystallographic coordinates, a total area of borders of all mineral grains in the aggregate, the specific square of their boundaries, the specific square of intergrowth boundaries of the ore mineral separately with grains of each minerals of the matrix of the mineral aggregate as well as traditional grainsmetric and modal composition. For realisation of these types of the analysis technologies of measurement, the program of calculation and the devices that are carrying out the analysis in a semi-automatic mode are possessed.

Jan 1, 2008

By J St George

Much of AucklandÆs transport infrastructure has been developed on surface with little or no consideration of underground options. Current and planned transportation routes are now facing high costs due to land values and increasing environmental resistance to surface development. The option of utilising underground space becomes a feasible investment decision for these links as well as being the only option to develop the rail network within the inner city area. Transportation tunnels offer a quieter, more energy efficient means of getting around with minimal impacts on the surface environment. One of the major impediments to tunnelling is the high construction cost, which is partly related to the risks of encountering unexpected ground conditions and/or the possibility of causing surface ground deformations which could damage structures. The geology of Auckland has had substantial investigation through various studies and projects. The sediments of the East Coast Bays Formation (ECBF) underlie most of the Auckland urban area. It is classified as a soft rock and is a suitable material to tunnel through using either a tunnel boring machine or a roadheader. This paper reviews the limited amount of tunnelling completed in the urban Auckland area, together with the international advancements that have been made in the tunnelling industry. From the known features of the local geology and the problems encountered historically, the likely risks of tunnelling in Auckland are presented and ways in which those risks could be reduced and managed, are discussed. In addition, contractual arrangements between client and contractor are assessed with respect to complicated projects (such as tunnelling), so that the risks can be managed to create efficient infrastructure routes with reduced costs.

Jan 1, 2008

By J H. J Holtzhausen

Never has there been more focus on the health, safety, and well-being of our employees at the workplace. Ever evolving expectations of individuals, companies and clients are shaping regulatory reviews and advancing standards across the world in the drive to zero harm. The technology is advancing at a rapid pace, which is now allowing continuous real-time monitoring of contaminants to take place in the harshest of environments.

Oct 12, 2022