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Aitik, a Boliden owned and operated open pit mine located in northern Sweden, will expand production from 18 Mt per year today to 36 Mt per year copper ore during 2010. The challenge for the mine operation is to double production with a planned increase of the shovel and truck fleet of only 50 per cent. This will be achieved through improved shovel and truck utilisation and productivity. In early 2005 Aitik started projects to enhance the utilisation of truck engine hours and to reduce fuel consumption. Both projects were successful, within a year efficient2 utilisation of engine hours increased from 60 per cent to 75 per cent and fuel consumption was reduced by six to eight per cent. The truck utilisation project focused on minimising idle truck hours by for example four operators on three trucks thus reducing idle engine hours to minimise lost time for breaks and shift changes. Other measures included focusing on improved dispatch usage, parking trucks when overtrucked, etc. Eco-driving was a project together with Swedish Road Administration with the objective to combine economical and environmental savings. To keep the focus on eco-driving a reward was set up for the shift team with the lowest fuel rate over rolling 15 weeks periods. Both activities included a comprehensive training program for mine foremen, dispatchers and truck operators focusing on efficient use of trucks from economic driving to optimised truck dispatching and minimising idle engine hours. Online monitoring of trucks activities and fuel consumption combined with continuous reporting gave shift foremen and management a tool to discuss and follow trends and individual shift team performance. The combination of close monitoring of mainly organisational practices and operator training resulted in significant productivity increase and lower operating costs without any capital investments.

Jan 1, 2007

By A Liu, X Wang, W Peng, Q Zhang

Pulp rheology plays a critical role in fine mineral flotation. Yield stress and apparent viscosity are two important rheological parameters affecting mineral flotation recovery. In this paper, the concept of pulp rheology and its measuring method are presented. The main factors, such as particle size, pulp concentration, mineral types, pulp temperature, inorganic salts, that affect the pulp rheology are systematically reviewed, and then followed by the discussion of the relationship between pulp rheological properties and flotation performance. Generally, high pulp apparent viscosity and yield stress values have been found to have an adverse effect on flotation recovery. In addition, due to the hetero-coagulation between the valuable mineral and gangue mineral, the pulp of mixed ore shows higher viscosity than that of the single mineral slurry. This paper is expected to provide some references for the efficient upgrading of low-grade and complex ores from the perspective of pulp rheology.

Aug 24, 2022

By A Vakili

Dilution is associated with considerable direct and indirect costs in underground open stoping operations. As shown in previous works, an improved ability to predict dilution enables the economic risks associated with unplanned dilution to be reduced. Depending on the width of the orebody and depth of mining, the economic performance of an open stoping operation can become even more sensitive to dilution. It is shown in several well-documented studies that as little as 1 per cent of additional dilution can impose millions of dollars of lost profits per annum. Optimisation of a stoping operation is therefore largely dependent on the ability of the operation to minimise dilution. This can only be achieved through sensible analysis of past and future performance of mined stopes using the most appropriate recent available technologies and tools. This article presents a new design process that utilises advanced geotechnical numerical modelling and various other analytical tools to assist with a more robust mine design of open stoping operations. The focus of this design process is on geotechnical factors affecting dilution during the life-of-mine. A recent application of this optimisation method for a mining operation is presented in this paper as a case study. Through the application of this method and various other operational improvements, the mine was able to deliver more consistent production and lower operating costs over its life-ofmine outlook and was able to reduce dilution by up to 50 per cent and achieve sustainable record high production rates.

Mar 29, 2023

By Chunbao Z, Zhenchuan Z

As known to the international mining sectors, Hunan province, called as ' Nonferrous Native Area ', is the main base of nonferrous metals Pro- duction in China. There are over 194 nonferrous mines in this province, most of them distribute over the basin of Xiangjiang River. The state of management of wastewater in Hunan's nonferrous mines is outlined.The experiences and economic benefit in the management and treatment of wa- stewater in Bofang and Mayang copper mines, and at Shizhuyuan polymeta- llic mine, are mainly introduced. It concludes with measures and recommendations for future management and treatment of wastewater in Hunan's nonferrous mines.

Jan 1, 1988

By D Stacey, J Matthews

Hunter Valley Operations in partnership with Orica Explosives designed a process to optimise coal extraction at depths greater than 65 m below the Hunter River in a safe and cost effective manner. The process involved a team approach to investigate the relationship between geology, mining sequence, vibration and blasting methods adopted. From this an optimum method for uncovering the coal was developed.

Jan 1, 2001

By N Kojola, A Vickerfält, J Huss

The possibility of using an acidic autogenous hydrogen direct reduced iron (H-DRI) slag as a basis for vanadium extraction is investigated. For a raw material to be suitable for producing high-quality FeV, the vanadium oxide content should be sufficiently high and the phosphorus oxide content in a tolerable range. Therefore, the feasibility for vanadium extraction relies on fulfilling two demands: the predominate partitioning of phosphorus to the metal and vanadium to the slag. Correspondingly, the behaviours of phosphorus and vanadium in the Al2O3-SiO2-FeOx-VyOz-P2O5-Fe system were studied experimentally. Slag, 10 g, was put in contact with liquid iron, 30 g, for different durations (2–24 hrs) in closed alumina crucibles at 1873 K. The slag composition was varied between 33.1– 49.3 wt per cent Al2O3, 27.1–46.7 wt per cent SiO2, 16.6–30.1 wt per cent FeOx, and 2.5– 8.8 wt per cent V2O3. The equilibrium phosphorus distribution was 0.42, while the vanadium distribution ranged from 7.6 to 43.4, increasing with the Al2O3- and the FeOx-content.

Jun 19, 2024

By G R. Ballantyne, G Lane

Dry milling circuits that include high pressure grinding rolls (HPGR) or vertical roller mills (VRM) and air classification have replaced dry ball milling in cement production, but how do they compare to wet milling and classification circuits in mineral processing plants? Two case studies are presented that compare the energy efficiency, wear, liberation and capital cost of dry and wet milling circuits. In both case studies the VRM and HPGR consume half the energy of a wet tumbling mill for the same duty. However, the dry classification system tends to significantly erode the energy benefits. A number of improvement opportunities are presented that have the potential to improve the energy and capital efficiency of dry milling circuits. These improvement opportunities focus on the dry classification system that consumes significant energy in heating and fan power requirements and requires a large proportion of the footprint.

Aug 24, 2022

By R Lau

The fire safety design for road tunnels includes the following aspects: active systems, passive provisions and operational procedures. The active systems include the smoke control system, fire suppression system, detection system and fire fighter’s assistance systems. Passive provisions include escape passages, fire separation and fire resistance systems. The operational procedures refer to fire fighter access, reporting and alerts, evacuation processes and crowd control.Currently, these systems are typically designed by different designers or teams. These systems are intended to work together in a coordinated manner to provide the desired safety outcome. However, in practice, this is not always happening. The fire engineering process is supposed to bring together all these aspects and arrive at an integrated safety system. The fi re engineering process in practice is not integrating the design with the practice or reality and is thus arriving at less than desirably efficient safety systems.The example of design inputs shows how disconnected each system design basis is. The smoke control system design is based on the design fire size. The performance of the smoke control system is to achieve a smoke free environment for a defined space for a particular fire size – the design fire. The fire suppression system – most commonly sprinklers or deluge systems, is designed according to codes and to achieve a certain water discharge rate. The fire detection system is designed to detect temperature rise/rate of rise and perhaps density of smoke. Fire separation is determined to provide a certain period of service – mostly for structural elements. Escape route size and location is determined mostly by code compliance. Evacuation procedures are determined by Authority operational requirements rather than human behaviour.To arrive at an integrated fire safety system, the design basis and performances must be coordinated. An approach using fire scenarios would ensure all systems are designed to a common performance requirement. This paper will discuss how the current design approach outcomes compared with a fire scenario approach. More effective and efficient fire safety systems would require the stake holders to understand the implication of this approach and to embrace this through the fire engineering process.

Mar 8, 2011

By A-M Fleury

There has been much progress on the issue of acid drainage over the past 20 years; however, significant challenges remain. The International Network for Acid Prevention (INAP) is attempting to address them by globally coordinating acid drainage information sharing and research. INAP pursues three branches of activities: it links AD research, practice, and people; it organises, sponsors, and participates in regional workshops as a forum for technology transfer; and it instigates and funds key acid drainage research projects. Through these activities INAP is helping the industry deal with what is arguably its most serious legacy issue.

Jan 1, 2003

By M Parcell

"Ventilation risks in an underground mine have essentially remained the same for centuries, yet theevidence suggests that there are many coal mines that have failed to adequately control these risks.The conduit for the knowledge learned by previous generations exists in the mining legislation. In an ideal world, mines would not need legislation to tell them what to do; they would resolve the risks to an acceptable level so as to protect the safety of persons in the mines based on the acquired knowledge. There will be some who have been personally aff ected by a mining disaster but for the majority they will be remembered as a vague recollection of an event from long ago. The mining legislation is the repository for the knowledge and outcomes from inquiries of past disasters. The challenge for the current generation, and the generations to come is to appreciate the legislation that exists, so as to not ælearn the hard wayÆ. In reviewing most disasters there is comment or discussion on the adequacy of the legislation, which ultimately results in some amendment to the law. For each person, there is an increasing responsibility to ensure that the same mistakes are not repeated. Understanding the legislation, its history and its purpose is the fi rst step in ensuring thatventilation risks are eff ectively managed. Failing to do this will be disastrous. This paper discussesthe relevance, importance and potential pitfalls of coal mine ventilation regulation."

Jun 1, 2012

By K Sommerville

BHP Billiton’s Area C iron ore operation has been in production since 2003. During 2010, below water table mining in the Marra Mamba formation commenced and dewatered ore has been successfully processed through the plant.The ability to mine below water table material increases reserves. Pits can be dewatered using a combination of ex-pit and in-pit bores. Critically it is important to allow suffi cient lead time to dewater. For Area C, in-pit bores yield the most water which presents challenges in every day operations when mining around bores. Operationally there are steep learning curves in obtaining equipment, training personnel and setting up infrastructure. Core risks include lifting, refuelling and maintaining gensets. The pipework, extraction and re-establishment work can be very manual.The challenges include blasting, mining, stockpiling, processing, water balance and disposal. Maximising up time on bores whilst minimising impacts to blast practices have evolved. Blast practices now align bores to the edge of patterns. Protecting bores have evolved from stemming bores with rock and re-drilling to using gas bags which require no drills. Based on moisture and material properties, mining of dewatered material can be categorised into three groups:1. normal,2. sheeting, and3. sheeting and top loading.Ore can go straight to the plant ore to drying pads where it takes between one and three months to drain.Stock management of these piles is important to ensure efficiency of the plant. Rules have been established for blending wet material to maintain feed capacity and some modifications to plants have been made. Dewatering of pits poses a challenge for water use. Initially turkey’s nests were established to capture water and use for dust suppression. As water abstraction has increased methods of management include using exhausted pits for storage and evaporators. Managed Aquifer recharge and use in potable water are being considered. An over arching coordination of the capacity and use are required.Important elements in dewatering include:• capacity models,• capital,• long to short planning,• day to day coordination, and • water level monitoring and balances. Success in dewatering requires a cross function team working towards a common goal. *This is an abstract only. No paper was provided for this abstract.*

Jul 11, 2011

By J J. L du Plessis, S Viviers, G Ratner

Escalating electricity costs are one of the biggest operational cost drivers in mining. The trend to use high-powered auxiliary fans delivering increased airflow to meet the dilution requirements of diesel equipment, together with the reliance on ducted systems rather than traditional flow-through systems to ventilate areas, increases the overall energy requirements of ventilation systems. To manage and reduce electricity costs energy management systems can be implemented, inefficient operating units can be replaced and the operation of energy-consuming components of ventilation systems can be optimised.This paper describes the process followed to design and develop an energy-efficient axial flow auxiliary fan. The fan-targeted design was based on static pressure and volume flow rate requirements incorporating higher overall fan efficiencies. A brief overview of the results is given, including the aerodynamic design procedure using computational fluid dynamic (CFD) analysis. The mechanical design criteria used, including stress analysis on the rotor and designs to improve the vibration levels of the fan, are also presented. Through this study it was demonstrated that the aerodynamically designed rotors using profiled and twisted blades improve the total fan efficiency considerably when compared with some of the older-generation fans using cambered plates. The latter were typical in the mining sector in South Africa at the time of the study where average overall fan efficiencies of standard cambered fans less than 63 per cent and some of the older-generation cast aluminium blades have peak overall fan efficiencies of about 65 per cent. Peak overall fan efficiency of more than 80 per cent was achieved by using the described design and development process. Additional benefits are that the fans are quieter due to the better aerodynamic design and have a longer operating life due to reduced vibration levels.In conclusion, the use of CFD to develop fans to deliver the required volume flow at the required pressure allows quicker design turnaround time. It furthermore allows the ventilation engineer the option to specify a specific fan and is not limited to an off-the-shelf catalogue fan. It thus allows engineers to purchase a fit-for-purpose energy-efficient fan. The introduction of reliable fan control systems may, however, still result in the biggest cost benefit for underground mines.CITATION:du Plessis, J J L, Ratner, G and Viviers, S, 2015. Design and development of energy-efficient secondary axial flow fans, in Proceedings The Australian Mine Ventilation Conference, pp 337–344 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By J F. Costa, A Grigorieff

Coal mining reclamation is a worldwide concern. This paper presents a Brazilian example where the economic aspects of reclamation are considered. The basic goal of the study is to transform the reclamation procedures into an economic process by integrating the use of land after reclamation and developing profitable post operations. Some of the activities considered in this case study include: using of the coal pit as a landfill, considering appropriate landfill design and construction; using the area for forest development; and developing grassland, forests of native species and the construction of ponds for fishery. This study will conclude that the mined area is: capable of storing large quantities of waste at a competitive cost and at a low environmental risk; commercial forest development is economically feasible; and the lakes and other reclaimed areas can be integrated into the landscape creating a fresh water supply and an area to raise cattle.

Jan 1, 2005

By H Jones

The paper outlines the adoption and evolution of ‘sustainable development’ as a concept in tailings management practices in the mining industry over the last 30 years. Over 500 lives have been lost in tailings facility accidents since World War 2. The paper outlines commonalities in many of these accidents, particularly the role of excess water. It considers the role effective tailings management can play in enhancing the social acceptability of mining in the future.Tailings management is a major operating cost at many mines while the cost of successfully closing tailings facilities is also very high. Current tailings management practices in the industry are outlined. The technical and engineering challenges of reducing potential risks associated with tailings by reducing water entrainment are described. The successful development of practical techniques to better manage tailings and reduce water consumption and wastage are described. For example, water removal in the alumina industry to produce a paste for dry stacking is now a reality.The future adoption of these new risk reducing techniques by the industry is discussed and the implications of the adoption or non-adoption of these techniques on the industry’s future ‘social licence’ is considered.

Nov 22, 2011

By C A. Foss, D A. Clark, D Hillan

While magnetic surveys are the most common geophysical method used in mineral exploration, magnetics and geology remain to be fully integrated quantitatively in iron ore provinces. Although high-resolution aeromagnetic data has been collected over prospective areas of the Hamersley Province, much of the information in the data sets has hitherto not been fully exploited due to a lack of suitable interpretation methods. Recent advances in the processing and modelling of magnetics in highly magnetic terrains, constrained inversion and 3D visualisation and understanding the magnetic properties of banded iron formations and iron ores potentially create the capability to generate realistic 3D mapping of magnetite and hematite concentrations over large areas. Initial processing of conventional total magnetic intensity data produces true potential field maps that are unaffected by local perturbations of the regional geomagnetic field direction by intense local anomalies. The true potential field can be converted into vector and tensor components, each of which emphasises different structural features of the geology. Scalar quantities derived from these components simplify interpretation, using new methods, developed by CSIRO and elsewhere, that are less sensitive to magnetisation direction. Preliminary interpretations allow interpolation between mapped units and structures and evaluation of remanence and anisotropy effects. Accurate modelling requires rigourous treatment of self-demagnetisation and magnetic interaction effects. Semi-automated constrained inversion, combining magnetics with available geological information and other geophysical data, can be utilised to generate models of disposition of major magnetic units and the 3D magnetisation distribution within them. The final stage of interpretation is to exploit the understanding of magnetic properties (susceptibility, anisotropy and remanence) developed over many studies by CSIRO, the University of Western Australia and others to convert the interpreted magnetisation distributions into 3D maps of magnetite and hematite contents, which are the quantities of direct exploration interest.CITATION:Clark, D A, Foss, C A, Austin, J and Hillan, D, 2015. Three-dimensional mapping of magnetite and hematite concentrations from reprocessing of detailed aeromagnetic data, in Proceedings Iron Ore 2015, pp 229–240 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

May I first of all say that I am fully conscious of the great compliment paid to me when I was invited to accept the Presidential Chair for this current year. I realise that it is an onerous task by reason of the fact that the Chair has been occupied in the past by so many able and distinguished men, and I realise also that I have been set a standard which is hard to emulate. "It is my desire however, in accepting the post that I may be able to contribute in some small measure to the further advancement Of the aims and objectives of the Institute and I thank you all for the confidence you have shown in me.Secondly, on behalf of the Company and in my Presidential capacity, I want to extend to each and everyone of you a hearty welcome to Whyalla and I hope that you will all return to your respective fields of endeavour feeling that you have had a most interesting, enjoyabIe and instructive time with us here in Whyalla.In this year of 1951 marking as it does the culmination of the first 50 years of Federation in Australia and yet another half century of human endeavour and progress, we are brought to a point where it is perhaps natural that we should pause, to review what has been achieved, in that span of time, and to look at the tasks ahead.It is no exaggeration to say that the story of Australian development since the inauguration of the Commonwealth 50 years ago has no more remarkable chapter than that of the-growth of its manufacturing industries.Each decade has borne witness to steady and substantial growth of our secondary industries and whilst it is true that our financial well-being still rests heavily on our primary production, we have, as a nation, moved surely in the direction of a more balanced economy. More and...

Jan 1, 1951

By T Takayama, M Matsumura, Y Konno

The steel industry accounts for 14 per cent of domestic CO2 emission in Japan, and iron ore sintering process occupies approximately three per cent. While Fe content in iron ore is gradually decreasing. So, the amount of concentrated iron ore will increase in the future. We have focused on magnetite concentrate as sinter materials, because magnetite can be easily magnetically beneficiated. However, it is experienced that blending magnetite ore resulted in increasing Fe2+ component in the iron ore sinter, which results in lower reducibility. Therefore, promoting the oxidation reaction from magnetite to hematite in the sintering process is countermeasure for reducibility. In addition, this promotion causes increase of oxidation heat, which results in high sinter strength and reduction of coke. It is assumed that the oxidation of magnetite tends to proceed in the cooling stage, where the oxygen partial pressure increases after the combustion of fine coke, but there are few studies on the effect of heat profile, especially cooling path. The purpose of this study is to design the effective sintering heat profile to promote oxidation of magnetite ore, especially, to investigate the effect of cooling path on sintered ore microstructure. In this study, magnetite ore and magnetite reagent were respectively mixed with calcium carbonate reagent. Then the mixed samples were pressed and formed into cylindrical tablets for simulating the adhesive layer of a pseudo particle. Through examining influence of maximum temperature and cooking rate on oxidation reaction of magnetite, we confirmed that the oxidation reaction of magnetite is suppressed at above 1350°C for maximum temperature, compared to 1300°C. Sintering at lower temperature is desirable because hematite is stable below 1350°C in the Fe2O3-CaO phase diagram.

Nov 8, 2021

By J Hadjigeorgiou

Narrow vein mining, as most types of mining, faces important geotechnical challenges. The specificity of geotechnical challenges in narrow vein mines stems from the nature of the deposits, which are often inclined, discordant and found within fractured rock or faults or in shear zones within country rock. This complicates the construction of representative geomechanical models and limits the applicability of several engineering design tools. Furthermore, in certain cases, the severity of encountered geotechnical problems is considerably greater in narrow vein than in wider orebodies. This paper provides an overview of geotechnical and other challenges in narrow vein mines with a focus on how these are currently addressed. Of particular concern is the use of manual labour working close to the mining face where there is greater exposure to geomechanical hazards. This review concludes with a particular emphasis on understanding the limitations of commonly used engineering tools and techniques to address geotechnical problems in narrow vein mines.CITATION:Hadjigeorgiou, J, 2012. Geotechnical challenges in narrow vein mining, in Proceedings Narrow Vein Mining 2012 , pp 15-22 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Mar 26, 2012

By T A. Short, P L. Brown

Kestrel Mine co-disposes around 1.5 Mt of fine (2SO4/t and to date around 9 Mt has been deposited. The mine plans to co-dispose of approximately 39 Mt of material, creating a dump with a maximum height of 35 m and a disturbance footprint of 260 ha. Benign materials suitable for rehabilitation are severely limited and no successful rehabilitation strategy has yet been demonstrated. A rigorous measurement and modelling program is resolving outstanding issues associated with acid rock drainage (ARD). The objective of the program is to develop and validate a strategy for dump rehabilitation that will control ARD and allow for mine closure. The strategy includes using a soil cover to reduce water flux into the dump to control the overall oxidation rate and to control effluent release. Monitoring of the oxygen distribution and water flux in the uncovered material commenced in February 2001 and monitoring in waste under a trial cover commenced in February 2002. Carbonaceous and sulfidic oxidation rates have been measured. Initial modelling indicates that the carbonaceous material has the general effect of slowing the rate of pyrite oxidation, lowering the maximum sulfate production rate and extending the time to oxidise all the sulfides. The combined approach of measurement and modelling provides a sound basis for assessing the performance of the trial cover and predicting the long-term quality and quantity of effluent at the base of the rehabilitated waste dump.

Jan 1, 2003

By L Xiong, W J Shi, J H. Wei

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. The Baizhangzi gold deposit is located in the northern North China Craton. The structural and lithological controls on the location and geometry of orebodies were studied through geologic survey, ore spatial configuration analysis and structural analysis. The orebodies of the deposit comprise auriferous quartz-sulfide veins and disseminated gold-bearing sulfides. The auriferous quartz-sulfide veins are dominantly hosted by the NNE- (and NE- and NW-) trending faults, which are subsidiary structures of the regional NNE-trending F2 fault. The subsidiary NNE-trending faults, having sinistral reverse kinematics, are associated with the sinistral reverse kinematics event of the F2 fault, which happened under a regional S–N-oriented compression stress field. The subsidiary NE- and NW-trending faults appear to be compressive and extensional respectively. These NE- (and NW-) trending faults are restricted to the granite intrusion and are associated with a sinistral strike-slip event of the F2 fault, which reactivated under a NW–SE-oriented compression stress field. It makes significant influence on geological evolution and distribution of different ore types that the strike of the F2 fault presents significant transition from NNE- to NE-trending in vertical. The ore-bearing disseminated host rocks, with widespread silicification and pyritisation, distribute in the lower inner contact zone of the granite intrusion, especially in the lower wavelike boundary of granite intrusion.CITATION:Xiong, L, Wei, J H and Shi, W J, 2015. Structural and lithological controls on the location of orebodies in the Baizhangzi lode gold deposit in western Liaoning Province, China, in Proceedings PACRIM 2015 Congress, pp 193–200 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015