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By S Zaffron, O Loffredi

A critical concern of any mining company today is its relationship with the different stakeholder groups impacted by the operational activity û communities, unions, vendors, local partners and competitors, local and federal governments, interest groups and non-government organisations. What ten years ago would have gone unnoticed, now, and even more so in the future, can drastically impact the profitability and even existence of a mining operation. This paper describes the development and delivery of a new paradigm for creating effective external stakeholder relationships. We report on the actual measurable results of an integrated and highly complex initiative led by Lonmin Plc (Lonmin) and Landmark Education Business Development (LEBD) that significantly altered the nature of the relationship with the stakeholders. Given the nature of the long-term investment required in a mining operation, any breakdowns or surprises in its relationship with external stakeholders brings with it the potential for major loss. The transformation of executive and senior management and community leadership was required to enable them to be effective in managing this complex set of circumstances.

Jan 1, 2006

By M Tayebi-Khorami

There is an increasing trend in the extraction and development of copper resources from complex deposits. The complex deposits pose mineral processing challenges, as they often contain low grade copper ore, relatively large quantity of clay minerals, complex texture, very fine disseminated ore, high amount of pyrite, and high level of impurity elements such as arsenic. With the amount of arsenic in concentrates increasing and with environment, occupational health and safety regulations becoming more restrict, there is a need for a processing method that results in no arsenic emissions and captures all arsenic while immobilizing it in a compound that is stable under a wide range of conditions, so it is suitable for long-term disposal. Some development work has been undertaken to examine the most effective arsenic treatment option for complex orebodies that contain arsenic, but a technically robust and economically viable option has not yet been developed. Previous research has demonstrated the possibility of separating arsenic-copper sulphides from other copper minerals by controlling the potential of the flotation pulp in the single mineral systems. The selective flotation of enargite from copper sulphides in a real complex ore system was studied by Tayebi-Khorami (2016), which is summarised in this paper. CITATION: Tayebi-Khorami, M, 2018. Arsenic in complex orebodies, in Proceedings Complex Orebodies Conference 2018, pp 132–134 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

The most frequently applied project evaluation criteria are the Net Present Value, the Internal Rate of Return, and the Pay Back Period. Unfortunately, the Internal Rate of Return and the Pay Back Period, if interpreted according to their traditional definitions, easily produce results which contradict the Net Present Value. The reasons for the Net Present Value incompatibility of the two criteria are that these criteria have not been adequately defined and so new, complete definitions are recommended. The concept of the True Rate of Return is proposed as a substitute for the interest rate that the Internal Rate of Return has been believed to represent. The redefined Internal Rate of Return and Pay Back Period criteria, as well as the True Rate of Return are all Net Present Value compatible and can, therefore, serve as independent project evaluation criteria. Also, the correct approach to the evaluation of mutually exclusive alternatives and the status of the often neglected borrowing projects in project evaluation are found to be quite important.

Jan 1, 1991

By A Densten, C Gimber

Surface water management and drainage is a key aspect of mine rehabilitation and closure planning. In the authors’ experience, drainage related problems are amongst the most common forms of failure in mined landscapes. The appropriate design of surface water infrastructure is therefore a key focus of practitioners. While there is currently a trend towards distributed drainage networks and avoiding hard engineered structures, in many situations (especially for existing landforms) engineered drainage structures cannot be avoided. CITATION:Gimber, C and Densten, A, 2018. A risk-based approach to drainage design standard selection for mine rehabilitation and relinquishment, in Proceedings Life-of-Mine 2018, pp 116–118 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 25, 2018

By C Hamilton

Stawell Gold Mines (SGM) is an underground mining operation located in Victoria, Australia. The mining method employed is long hole retreat stoping, utilising up and downholes and artificial concrete pillars. Stawell is currently mining the Golden Gift and Magdala orebodies.Access to the Magdala and Golden Gift deposits is via 6.0 m wide by 5.5 m high declines developed at a gradient of one in eight to one in seven from the surface to a depth of 1500 m, with a planned depth of 1650 m. From the declines, cross cutting drives are developed to intersect the orebodies. Orebodies in the Gift system are discrete lodes which are generally mined from a bottom up centre retreat to minimise geotechnical stresses.Ore development fronts are currently located between 1000 m and 1500 m below surface, with all ore being hauled to the surface using a fleet of 60 tonne underground trucks. With the use of conventional pyrotechnic long period (LP) delays, broken rock of combined ore and waste is thrown 10 m from the face and the materials hauled to the surface. The majority of the mullock from development is consumed in the underground as backfill.With the use of Orica Mining Services eDev™ Electronic Blasting System for Tunnelling, the waste is thrown up to 40 m from the face, while majority of the ore is left 5 - 10 m from the face, effectively segregating ore and waste. This enables significant recovery of gold values with minimal loss and significantly reduced dilution. By using this technique in ore drives with a 30:70 waste to ore ratio, SGM is able to haul 24 000 tonnes less mullock to the surface annually. Resue mining is applied to narrow vein headings and gives a 40 per cent grade increase at the faces as well as increasing the economic footprint of development. This will also contribute to an improved grade profile for the year from 3.98 - 4.16 g/t Au and allow extra capacity for ore haulage from stoping and for milling.This paper describes the application and the successful blast outcomes achieved using the eDev™ Electronic Blasting Systems for resue mining at SGM. Results to date, since commencement in March 2010, have been achieving significant benefits in terms of ore grade as confirmed by geologists grab sample grades. Face advance have also shown improvement with better breakage of perimeter holes giving improved face profile. These benefits are delivering increased productivity and safety performance when compared to other resue firing techniques.

Mar 21, 2011

By Majorkiewicz A

Engineering of gold treatment facilities complete with infrastruc- ture in a remote location such as Papua NewòGuinea present unique problems to the design team. Site location, topography, ground conditions and infrastructure are some of the major hurdles to overcome when setting out on the design of such plants. This paper discusses two such plants, located in two distinctly different areas of Papua New Guinea and the solutions evolved in order to design successful operating facilities.

Jan 1, 1991

A novel problem-solving exercise for undergraduates is described which is directly relevant to production supervision. It is based on the fictitious Metwin Plant which produces refined metal from sulphide concentrates via a hydrometallurgical route with six unit operat- ions. Students are given details of the chemistry, process engineering and normal operating conditions. They are also given min- imum data for the Plant when it is operating with a fault. By requesting further data, for which they are 'charged', the students must diagnose the fault. The responses of students to the exercise are described. The data were produced by computer simul- ation of steady state operation under normal and various faulty conditions. The development of this program was an educational experience for the author and it stimulated new interest in metallurgical process engineering.

Jan 1, 1984

In October 1993 it was decided to undertake the fourth phase of mining at Big Bell. This decision followed the exhaustion of open pit reserves in January 1993. Two stages of mining were proposed for the new underground mine. The initial stage would mine the remnant ore, consisting of the rib and crown pillars and lower grade ore on the hangingwall and footwall side of the old open stopes, which were mined from the 1930s to 1950s. Most of the old open stopes were backfilled with either deslimed mill tailings or development mullock, both of which were economic to recover. However, the mineable ore from this resource was difficult to evaluate. The second stage focused on mining ore outside the remnant areas and was initially proposed as a Core and Shell method under a caving hangingwall. This method has since been superseded with sublevel caving, in part due to the very high and deviatoric stress conditions encountered at Big Bell and the relatively long mining cycle required for open stoping. The problems and challenges discussed in this paper will cover the identification of remnant ore reserves, dewatering the old workings, and remnant mining.

Jan 1, 1998

By M Zhu, G Tranell, J You, K Tang, X Ma

The thermal conductivity of slag is critical for the efficiency of high temperature metallurgical processes such as the smelting reduction of ferroalloys, the ladle refining and the continuous casting mold flux in steelmaking. Experimental determination of slag’s thermal conductivity is fraught with challenges, as seen in yielding data for the SiO2-Al2O3-CaO system that are often inconsistent and widely dispersed. In molten slags of this system, thermal transport occurs via phonons within the network structure. To quantitatively describe thermal conductivity based on the microstructure, hightemperature Raman spectroscopy was employed to measure the silicate tetrahedra Qi (i = 0, 1, 2, 3), with Q4 species inferred from mass balance. This study also integrated molecular dynamics simulations to provide a fundamental understanding of the microstructure units distributions. Machine learning algorithms, especially deep neural networks, were applied to establish the relationship between slag composition and the configuration of tetrahedra. The thermal conductivities were then connected with silicate tetrahedra Qi using an Arrhenius-type formalism. This study sets the stage for extending our findings to more complex, multicomponent slags, enhancing their practical application in industrial processes.

Aug 21, 2024

The three papers reviewed here consider different problems of mine management. Comparison of two of the papers demonstrates a marked contrast between the old and the new, in terms of mine management and impacts. The third paper discusses post-mining rehabilitation. The paper "The impact of a derelict base metal mine on the aquatic environment", by Brooks and Mclveen contrasts strongly with the paper "Narbarlek Uranium Mine design, construction, operation monitoring and decommissioning of the water management system" by McLoughlin, Grounds and Weatherhead. Brooks and Mclveen detail the contamination emanating today from the Conrad Mine in New South Wales which was mainly operated for 15 years at the turn of the century and later for 7 years in the 1950's. The mine was apparently developed over the years on an intermittent, ad hoc basis with no regard to contamination management, resulting Ti significant contamination persisting through time. This type of mining development is the antithesis to the type of planned mining and management operation which was carried out in Arnhem Land at Narbalek, and which apparently resulted in no uncontrolled contaminant release and successful decommissioning of the mine.

Jan 1, 1988

By R Lau

In recently completed road tunnel projects in Queensland, such as the Airport Link and the Clem7 tunnels, there is a smoke duct running along the roof of the carriageways to extract smoke in case of fire. In New South Wales, no road tunnels have a smoke duct. In the Melbourne City Link tunnels, there is a small smoke duct running along the roof. All of the tunnels are safe as claimed by the designers and authorities. However, there is significant cost associated with providing a full size smoke duct compared with no smoke duct. This paper is going to present a comparison of the road tunnel safety with a smoke duct and those without one from a risk perspective. It further discusses the cost-effectiveness of such provisions and whether similar levels of safety could be achieved without a smoke duct.CITATION:Lau, R, 2014. Smoke duct or no smoke duct for road tunnels, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 83–86 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By Kavetsky A

A new model of flotation is presented which allows predictive calculations of total solids flows and metal grades and recoveries to be made for industrial flowsheets. A method of making these calculations is presented and illustrated with examples. The problem of determining sufficient flotability characteristics from a sample of circuit feed to predict the behaviour of that specific ground ore in the flotation circuit (ie performing flotometric analysis) is addressed, and some suggestions are made for its solution. A feature of the flotation model is its practical technological orientation, allowing determination of a small number of ore flotability parameters by fitting observed batch kinetic flotation data. The unit model explicitly includes the cell aeration as total bubble area per unit pulp volume, and pulp residence time. Although more complex unit models are feasible, it is thought that this model is sufficiently realistic to illustrate the points made. The modelling approach is illustrated by application to flotation data from a Kambalda ickel circuit. The model is parameterised and ore flotability parameters are back-calculated from batch kinetic data. These parameters are then used to fit the observed behaviour of the industrial circuit by numerically adjusting the unit aerations. Finally, it is shown how the model may be used to predict the effect of circuit and ore changes on the circuit's technological indices.

Jan 1, 1992

Project Hobson involves the replacement of an existing 90-year-old above-ground sewer that crosses Hobson Bay in Auckland, New Zealand, and which is nearing the end of its economic life, with a 3 km long, 3.7 m internal diameter segmentally-lined bored tunnel. The $118 M project will offer several benefits to the owner, Watercare Services Ltd, and the local community:provide capacity to meet projected growth in the region,virtually eliminate wastewater overflows into Hobson Bay and the Waitemata Harbour, andremove an obtrusive visual feature and open up the bay for recreational purposes. The geology in the region is a sedimentary formation, which has been significantly influenced by volcanic activity; 49 volcanoes are present within 20 km of the nearby city centre. The geology along the alignment is dominated by two palaeovalleys which have been infilled with a combination of marine alluvium and volcanic deposits. Watercare Services Limited has elected to manage and share tunnelling risk through, among other key measures, the implementation of a geotechnical baseline report (GBR); one of the first uses of this type of document in Australasia. This paper describes the general principles behind the use of a GBR, the development of the GBR used in Project Hobson and some lessons learnt.

Jan 1, 2008

More than ten seafloor massive sulfides (SMSs), which tend to be enriched in Au and Ag with varying amounts of Zn, Pb and Ba, have been reported in Japanese Exclusive Economic Zone (EEZ) including the Jade hydrothermal field in the Izena cauldron Okinawa, theSunrise deposit in Myojin knoll Izu-Ogasawara, and other active deposits found in the past 20 years. From the fiscal year 2008 some universities in Japan will begin development of sensing devices to delineate surface distributions of known SMSs and to find new ones. The devices would be deployed by an autonomous underwater vehicle (AUV) or remotely-operated underwater vehicle (ROV) later in active hydrothermal fields and potential areas in the EEZ. On the other hand, different laboratories are planning to research and evaluate SMSs with state-of-the-art methods such as the benthic multi-coring system and geophysical devices to collect information in deeper parts of the SMSs. In this session recent projects on exploration and evaluation of SMSs with some new trials including geophysical and geological surveys in Japan will be reported. An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation.

Jan 1, 2008

Although laterite ores already provide a significant proportion of the world's nickel and cobalt production it is anticipated that they will surpass sulphide ores as a source of nickel in the next century. The most recent period of greenfield nickel project construction was during the 1970s when it was notable that all of the eight new plants were based on treating laterite ores. This was because of the relatively large selection of available high grade laterite ore deposits amenable to cheap open cast mining and a paucity of high grade sulphide ore prospect alternatives. Of the three processing options for treating laterite ores: 1. smelting for the lower horizon saprolite ore, 2. ammonia; and 3. acid leach for the upper horizon limonite ore, smelting currently accounts for about 80 per cent of nickel production. In the future, as saprolite ore grades decline because of relatively high exploitation rates, the incentive to process the large untapped reserves of limonite ore will increase. The high cobalt content of limonite ore also makes it ideally suited to processing by a hydrometallurgical rather than smelting route. With only two exceptions, all saprolite smelting operations have a Class 2 nickel end product (largely ferronickel) and do not produce a cobalt by-product. As a result of technological advances, the modified ammonia leach process for limonite and transition ore as undertaken at Yabulu, now allows the production of pure nickel metal as a Class 1 product, along with significant tonnages of cobalt by-product. The mixed Ni-Co sulphide intermediate product of the pressure acid leach processing of limonite ore at Mon is converted to Class 1 nickel and cobalt metal at Fort Saskatchewan, Canada.

Jan 1, 1996

By C Sennersten, A Hellicar, C Lindley

Traditional methods of resource modelling and mine planning rely upon geostatistical methods applied to exploration drill core data to derive a three dimensional model of the distribution of metal grades, quantised into rectangular prisms or blocks. The resulting block model is a primary input into short, medium and long term mine planning. However, block attributes are averaged or interpolated over a complete block, meaning that information at smaller scales is lost to the mine planning process. Grade engineering for new mining methods, such as the development of more accurately controlled blast designs, continuous miners for hard rock and sensors for rock properties that can be distributed along the operations process and value chain, allows excavation to be much more selective than traditional blasting, and provides data for driving earlier separation of waste from ore. This selectivity can be optimised if the resolution of resource models can match or exceed the spatial resolution of selective mining technologies. Opportunities for selective mining increase as a deposit becomes more heterogeneous. This leads to an interest in methods for estimating the distribution and characteristics of mineral heterogeneity within the ore-body. The objective of this work is to present some definitions of mineral heterogeneity, and to explore how heterogeneity as defined can be measured and inferred within ore-bodies.CITATION: Hellicar, A, Sennersten, C, Lindley, C and Evans, B, 2018. Heterogeneity assessment for grade engineering in complex ore bodies, in Proceedings Complex Orebodies Conference 2018, pp 11–13 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

By OÆBrien D, Priddle D

In order to avoid costly moisture penalties on coal shipments and to minimise rail freight costs, screen bowl centrifuges were selected and installed in the Mount Thorley Coal Preparation Plant for dewatering fine coal product. The Mount Thorley fine coal circuit consists of desliming the -0.5 mm (ww) fine coal in two stages of classifying cyclones prior to recovery by froth flotation. Provision has been made to bypass the flotation circuit with the classified flotation feed reporting directly to product and the centrifuge dewatering circuit has been designed to handle either flotation feed or flotation product. Major mechanical failures of the gearboxes and the ceramic tiling occurred early in the operation life of the machines which led to design changes being made to achieve satisfactory operation. This paper discusses the operating experience at Mount Thorley with respect to both mechanical and metallurgical performance of the screen bowl centrifuges since their installation in 1985.

Jan 1, 1989

The blasting of the 2190_6095 stope at Kimberley Nickel MineÆs Sally Malay operation in Western Australia is an example of what can be achieved with electronic detonating systems when a drill and blast engineering team is faced with complex blast geometry and a major pump station in close proximity to the stope. Using Dyno NobelÆs HotShotÖ system, the engineering team successfully designed and initiated the 36.5 Kt stope firing, with a powder factor of 0.35, resulting in no damage to the pump infrastructure, better fragmentation of the ore and less overbreak in what had previously been a geotechnical and geometrically challenging stoping environment. This paper will discuss the design parameters used for this stope blast as well as the benefits the operation found in using precision detonator timing in this 252 hole shot over two levels using a combination of up and down and slashing rings that were initiated in four different directions.

Jan 1, 2007

Multi Torque Industries and Jadefoil have developed a safer, more efficient method of explosive protection, retention, placement, and constraint. In particular, this refers to advancements in airbag technology, where the system will offer an alternative to conventional gasbags and decking methods to provide a far more controlled and safer working environment. Airbags have provided operator control and reliability which has not until now been possible in this type of application. The benefits have been noted by current users and the advantages have provided an increase in productivity and significant savings in explosive waste. Obvious problems with gasbags lie in their instability in hot conditions where the danger is associated with gas canisters exploding with great force posing a significant risk to operators. Other problems associated with the decking systems currently on offer is the lack of versatility and operator control. The airbag systems give the operator full control to guarantee accurate placement, assured retention whilst boasting a quick operation of less than a few seconds for conventional void blocking, decking and plugging. One of the main advantages of the airbags is that the operator has full control over placement and retention force, therefore in wetter conditions where slippage can be a problem extra air can be added at the operatorÆs discretion to ensure a sufficient grip. Technical calculations coupled with experimental testing have demonstrated that an airbag will support the weight of a 30 m water column in an 89 mm hole at an initial bag pressure of 5 psig. Applications are increasingly growing whilst more customers embrace their use. Advancements such as the ability to deck in overhead holes, block voids in overhead holes at any depth, explosive retention in very wet conditions, longhole stabilisers to prevent hole closure and concertinaed liners reflect a dynamic potential for new technologies. All of these applications provide a decrease in explosive waste, an increase in operator safety, an increase in explosive protection, and an increase in productivity.

Jan 1, 2004

By M Stewart, J Petrie, L Basson

This paper explores tools which have the potential to promote and assess the formation of partnerships between the minerals and energy industries to enhance the economic, environmentally responsible and socially acceptable use of energy. There is a need to look at energy provision and energy services in an integrated manner with key drivers for economic development û both locally and regionally. The minerals sector will remain highly significant to regional economic development in a number of globally significant regions in the medium term. Furthermore, mining, minerals and metalsÆ projects are both consumers and, in some cases (potential), generators of large amounts of energy (electricity included). It is therefore appropriate to focus on the promotion of partnerships between energy providers and the minerals sector which seek to improve resource efficiency within the combined minerals/energy envelope, guided by the tenets of Sustainability.Whilst there has been considerable development of systems analysis tools in recent years to address this sort of æcomplex systemsÆ analysis (Life Cycle Management, Cleaner Production and Industrial Ecology arguments for example), there is no effective roadmap available to decision makers to guide the selection and exploitation of these tools in different contexts. Our previous work developed a Decision Support Framework (DSF) which provides some guidance here, but only within the context of coal-based power generation. The DSF employs the tools of Multi Criteria Decision Analysis (MCDA), within which trade-offs between competing objectives are explored in such a way that alternatives can be compared without necessarily reducing all the different cost and benefits to a common basis (eg a monetary basis). Even if the existing DSF is extended to include all aspects of supply-side management, it is still lacking the necessary tools to analyse energy providers as dynamic network partners within minerals projects (or indeed any resource or manufacturing sector). New models are required for this, which firstly, seek to characterise such network structures, and secondly, enable the application of the necessary analytic tools to exploit these partnerships and networks for optimal performance.This paper explores the development of such an integrated set of network analysis tools, and their relation to the DSF. Due consideration is given to the choice of the attributes needed to characterise partnership linkages and network integrity (eg security of supply of electricity), and the efficiency of material transformations within any node of the network (as a function of energy consumption), and the impact that this has on the viability of other linkages (eg due to reduced availability of raw materials). We discuss how these perspectives help shape the form of objectives to be considered by MCDA.

Jan 1, 2004