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By K Koskinen, S Ronkainen

The flow field induced in an Outokumpu TankCell and by an OK rotor-stator mixing device in a laboratory and a process size flotation cell was modelled numerically using computational fluid dynamics (CFD). The primary target was to discover and reproduce the various interactions between the flow field and the flotation cell by numerical means. As power consumption depends sensitively on flow field, it can be regarded as a top-level derived quantity (or measure/metric) indicating the validity of the numerically obtained flow field. Having properly validated numerical means to produce the flow field the influence of various design parameters can be captured with certain accuracy. In addition, separate gas and solid phase models for bubbles and solids, respectively, were implemented. The comparisons between velocities and turbulence quantities measured using the laser doppler velocimetry (LDV) technique and CFD modelling were performed. The grid generation was performed with the commercial Gambit 1.3 and the subsequent integration and solving of the resulting algebraic equations with the commercial CFD-code Fluent 6.22. The computationally economic multiple reference frame method was included to model the moving rotor blades. Gas and solid phase models were modified mixture models.

Jan 1, 2005

By M Wortley, J Korteniemi, D La Rosa, L Rajavuori

Geometallurgical modelling of an orebody provides benefits to a mine by gaining a better understanding of the ore characteristics and how they affect the performance of the concentrator. With this knowledge, plant operating conditions can be adjusted to optimise throughput and recovery in advance of the arrival of particular ore types. Therefore, it is extremely important that the origin of the ore being processed is known as accurately as possible. Depending on the homogeneity of the ore characteristics, reliance on assumptions about stockpile residence times, scheduling and material handling can render the best geometallurgical models useless.The solution adopted at Agnico Eagle’s Kittilä mine was to utilise Metso SmartTags™ and in-house expertise to develop a system that continuously and accurately links geotechnical and lab data from the mine to the performance of the plant. This application presented several unique opportunities and challenges. For example, this was the first installation of a SmartTag™ system for geometallurgical modelling in an underground mine. Challenges included the fact that the system installation is routinely subjected to temperatures below -20°C.The system was installed and commissioned in early 2013 and has been operating continuously since. Kittilä has begun to see the benefits of the system, with an increased understanding of how different ores are processed in the concentrator. Other advantages include the ability to alert operators about the arrival of difficult ores and a better understanding of the ore handling systems.This paper describes the installation and use of the system at Kittilä and details some of the geometallurgical relationships that have been developed using the data collected so far.CITATION:La Rosa, D, Rajavuori, L, Korteniemi, J and Wortley, M, 2014. Geometallurgical modelling and ore tracking at Kittilä Mine, in Proceedings Orebody Modelling and Strategic Mine Planning Symposium 2014 , pp 291–298 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 24, 2014

The difficulty in screening of ores when the moisture contents reach certain critical levels has resulted in mining circuits using wet processes for screening. While this has been acceptable in past years it is no longer acceptable in certain countries and where the mining company is looking to reduce its impact on the surrounding environment.   Various mining companies have been looking at ways to remove the need of using water, with all its inherent drawbacks and to be able to produce its desired products in a dry process.   This would have the benefits of less environmental impact and cost, (due to not requiring wet processing equipment), less power consumption (reduced equipment needed), no corrosion issues, no contaminated waste waters and reduced maintenance activities.   Until recently this has proven elusive or with technical restrictions with current available acceptable technologies for high capacity plants.   One major mining company began seriously exploring ways to overcome this dilemma so that they did not replicate their current ways of operating for their new expansion plans.   They partnered with Metso Minerals to undertake extensive groundbreaking laboratory test work and provide potential solutions as to how to solve this. The laboratory test work proved interesting enough to design, manufacture and test on the actual mining site a prototype screening machine in the circuit.   This break through in screening technology reduces the environmental impact on the area in which the mine is located by: eliminating the storage and use of water, reduction in energy consumption due to having no pumps in the plant, reduction in plant costs and the upstream affects on the environment process used to manufacture and ship the materials the plant structure is built from, and no large tailings dams to take up land space and affect the environment through groundwater/ water table contamination and the negative effects on animals and ecosystems Laboratory test were conducted and a full size machine was installed at the plant site along side conventional machines. The screen size (2.4 m wide x 6.1 long double deck) was determined by the size of screens currently in operation at the mine. The parameters that were explored were: types of screen surface (polyurethane, woven wire etc), types of screen motion (linear, circular or elliptical), angle of motion ( 40,45,55,60 degrees etc), and throw (amplitude), speed and 'g' force.

Jun 1, 2010

During the course of an investigation into the fundamental chemistry of the cyanide process, it became evident that the usual method of determining protective alkalinity was not completely satisfactory. T.he routine method for the determination of protective alkali by first removing free cyanide by the addition of silver nitrate, followed by titration of alkali with dilute acid using. phenolphthalein as indicator, can be shown to give correct results only when the alkali is a strong base. For other sUbstances, the alkali so determined is not the protective alkali. In view of the complications associated with the presence of zinc in cyanide solutions the discussion will be restricted in the first place to solutions free from zinc. Until the chemistry of simple cyanide solutions is placed on a quantitative basis it will be difficult to elucidate the behaviour of complex mill solutions.By the use of physico-chemical theory, it is possible to treat certain aspects of 'the chemistry of cyanide solutions in a manner which not only illustrates the important variables involved, but which also shows the need for care in interpretIng results obtained by conventional methods.In the following, comparatively simple systems are discussed; the principles established should be of use in interpreting the behaviour of more complex solutions. The methods described are not intended for routine work, but may be regarded as supplementary to the usual analysis carried out for the control of plant solutions, or as alternatives to be used when the latter do not appear to be satisfactory.

Jan 1, 1948

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 Moritz P

Thiourea has been recognised for a long time as an acid-stable complexant for gold. Generally, the use of thiourea has been shown to exhibit enhanced leaching kinetics compared to cyanide but suffers the disadvantage of excessive reagent consumption. Thiourea leaching is particularly com- patible with the extraction of gold from refractory ores. This is due to the need for an oxidative pretreatment to liberate the gold. Such pretreatments typically result in the production of an acidic residue. The application of novel thiourea leaching technologies to the extraction of gold from a bioleached pyrite concentrate was investigated. The interac- tion of leach variables with thiourea consumption and gold extraction was established. An economic assessment of thiourea leaching was compared with conventional cyanidation. The results indicated that gold leaching of the bioleached residue using thiourea compared very favourably with cyanidation.

Jan 1, 1991

At the outset, I guess we should define what we mean by "com- modities". In the 20 minutes or so which I have for this paper, it is impossible to tackle all commodities -one would need to con- sider not only the base metals but also the ferrous iron and steel products as well as energy commodities such as coal, oil and even uranium. For the purpose of this address however, I would prefer to refer to the principal non-ferrous commodities: copper, lead, zinc, aluminium and nickel and, I would like to consider some of the changes which have taken place in the industry over the past 20 years-and the likely reasons for these changes. I would also like to dwell a little on the future and some of the key issues which-may influence the future path and direction of the metals industry.

Jan 1, 1988

With the next mining boom looming, the industry will once again struggle to meet skills needed as the current generation boomers are set to retire. In order to meet these needs it is going to need to focus on what underutilised human resources - in particular women - want!   Women comprise around 14 per cent of the mining workforce, compared with a 45 per cent participation rate in the work force overall. Within the industry, women still make up only one per cent of trades people, eight per cent of operators/production employees, 12 per cent of engineers and 11 per cent of executive management.   It may be worth pointing out that mining has an age profile skewed towards the older end of the spectrum. When it comes to employee retention, what women want may be a good starting point to examine, more broadly, what all employees might want (but are too afraid to ask!).   Women in mining want the following: To be scrutinised for their work and performance, not their personal lives, appearance or relationships. True pay equity. This is addressed at lower levels between companies but at professional levels the salary differentials begin to appear and little is done to identify why this continues to be the case. Recognition and acceptance that women can have different work-styles, and that diversity of work-styles is an asset to be nurtured not a threat to be neutralised! Recognition that a more diverse workforce demographic that better reflects society at large will assist the company in its dealings with many diverse stakeholders from society at large. For employers to recognise that a career break to accommodate caring responsibilities does not mean that an employee's commitment to progressing their career is any less than that of someone who has not taken a career break. Similarly, for employers to recognise that working part-time for to accommodate caring responsibilities does not mean that an employee's commitment to progressing their career is any less than someone who works a more traditional roster. Access to affordable and quality child care compatible with mining rosters in mining towns. Zero tolerance for bullying and harassment, and workplace cultures that promote respect and safety. This is an ABSTRACT ONLY no paper was prepared for this presentation.

Jun 1, 2010

Technological advances evolve in different ways; many are the result of years of application of scientific method. i.e. Observation Deduction Hypothesis Proof In the mining industry, better explosives, drill bits or reagents are likely to evolve in this way. The scientific method is suited to the application of conventional management structures. Other advances are simply the result of a "brainstorm", or building a better mousetrap. Such inspiration probably resulted in "Split Set" rock bolts, or the first use of a vacuum cleaner principle for shaft mucking. Individual consultants can apply lateral thinking to generate such inspiration. In gathering material for the presentation of this paper, I sent a.letter to all members of the Mineral Industry Consultants Association asking them to nominate problems in the industry requiring investigation. The answers have been divided into two classifications - contract research underway and identified problems requiring solutions.

Jan 1, 1986

By P Joyce, A S. Ray, P S. Thomas, J Haggman

Climate change and global warming present a significant challenge as unsustainable levels of greenhouse gas emissions arising from human activities continue to be emitted. The cement industry is responsible for between five and ten per cent of annual world carbon dioxide emissions; most arising from the manufacture of Portland cement (PC). An effective way of reducing emissions is by incorporating supplementary cementitious materials (SCMs) as partial PC replacements. SCMs are silicate or aluminosilicate based pozzolanic materials which, in finely divided form, combine with water and calcium hydroxide (lime), liberated by cement hydration, to form compounds exhibiting cementitious properties. Pitchstone is such an aluminosilicate and has the potential to act as an effective pozzolan for partial replacement of PC. In North Queensland, Australia, a vast deposit of pitchstone is mined and processed for expandable perlite aggregate. During the classification stage of the excavated natural material, waste pitchstone fines (PF) less than 0.5 mm in size are generated. This study evaluates the waste PF as a viable, eco-friendly pozzolan for the partial replacement of PC. The reactivity of the PF is compared to fly ash (FA), using the pozzolanic compressive strength activity index (SAI) after seven, 28, and 91 days ageing at 20 per cent and 40 per cent PC substitutions. PF was found to be comparable to FA as a pozzolan at 20 per cent PC substitution at all ages tested. However, for the 40 per cent substitution blends significant strength was only achieved at 91 days ageing for the FA blend. The pozzolanic reactivity was also investigated using thermogravimetric analysis to determine the degree of free lime present after 91 days. In all cases where an SCM was added, the free lime was observed to be consumed with increasing age.

Jan 1, 2008

By J Jones, J Blunt

"The requirement for environmental approvals and associated environmental impact assessments (EIAs) is now commonly regarded as a key milestone and body of work during project development. EIAs can be undertaken at various phases during project development, generally either:\ during the scoping or prefeasibility studies, where limited project information is available and the mitigation and management measures of the EIA become a set of criteria and commitments that control project design during the feasibility study, as an iterative approach whereby mitigation and management measures are developed through an integrated process with the engineering team, and measures are included in the feasibility study cost model following the feasibility study, where detailed project design information is available, the cost model is complete, and the EIA is an assessment of a fixed project with limited opportunities for mitigation and management measures to be integrated into engineering design. This paper investigates the advantages of integrating EIA into life-of-mine planning during the feasibility study phase, using the Tampakan Copper-Gold Project (the Project) as a case study. The Tampakan Project is located in the Philippines on the southern island of Mindanao. The Project involves the proposed development of three main areas of infrastructure:a large-scale, open pit copper-gold mine and associated mine site infrastructure (including tailings and mine waste storages, fresh water dam, concentrator, etc) a power station, port and filter plant (PPFP), located approximately 60 km from the mine a pipeline and transmission line linking the mine and PPFP sites.Examples of engineering measures developed through an iterative process to mitigate and manage predicted environmental and social impacts include design of water management infrastructure, modification of the disturbance footprint (eg roads realigned to avoid critical habitat) and realignment of project infrastructure to minimise impacted water catchments.CITATION:Blunt, J and Jones, J, 2012. Integrating environmental impact assessment into life-of-mine planning, in Proceedings Life-of-Mine 2012 , pp 143-152 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 10, 2012

By N Patel, S Narendranathan, T Mok, J Lowe

The Hazelwood Mine (HM) commenced operations in the 1950s and was originally operated by the State Electricity Commission of Victoria (SECV) prior to it becoming privatised. ENGIE, the current owners of the Hazelwood Mine ceased operations in 2017 and have since transitioned the site into the rehabilitation and closure phase, which is to encompass a full pit lake as part of the final landform. A key aspect of HM closure is the maintenance of long-term stability of the pit slopes to deliver a final landform which is safe and sustainable, particularly given its proximity to critical public receptors. The Princes Freeway, which is the primary access route to the Latrobe Valley (LV), and the Morwell Township are both located immediately to the north of the HM. With due consideration of the mine void and nearby public receptors, the authors performed slope stability assessments of critical mine

Aug 2, 2023

By P Vass, C Butler, J Condon, B Hooper

DeGrussa Copper Mine, resource status 10.2 Mt at 5.7 per cent Cu, 2.1 g/t Au (Sandfire Resources, 2013), commenced concentrate production through its 1.5 Mt/a conventional copper flotation processing plant in September 2012. Geometallurgical assessment during the feasibility study identified potential process-critical ore factors that required further investigation to determine potential impact on processing. Ore characterisation and metallurgical processing performance test work of ore types ensued and subsequently, the first quantitative DeGrussa geometallurgy model was born. Now one year into steady state production, the geometallurgical program has evolved significantly from its infancy and provides valuable insight into ore characterisation and behaviour in the processing plant. This paper details geometallurgical investigations undertaken at DeGrussa to date; from feasibility metallurgical test work through to geometallurgical modelling and management practices, as well as reconciliation between observations at feasibility study level and subsequent observations in production.CITATION:Condon, J, Butler, C, Hooper, B and Vass, P, 2013. DeGrussa Copper Mine, Western Australia - feasibility to first production: a case study in developing a working geometallurgy model from first principles, in Proceedings The Second AusIMM International Geometallurgy Conference (GeoMet) 2013 , pp 59-66 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 29, 2013

It is very rare in the underground hard rock environment to find a deposit that is ideally suited to a specific mining method. Usually the irregular shape of the orebody will allow the deposit to be extracted by more than one mining method. During the prefeasibility stage, a number of conceptual mine designs are generally evaluated to see which offers the best method of extraction for the deposit. The selected method is usually based on key decision criteria such as the overall extraction of the orebody, the amount of metal produced annually and the unit cost of production. Often the prefeasibility study document will state that the project has an NPV of æxÆ million dollars. This statement can be made without any quantitative consideration of the likely risks of the mining methods reviewed or the level of confidence in the estimation of the NPV. By assigning a probability of failure to each component of the mining cycle a measure of the risk for each method can be determined. One mining method may provide the highest NPV when it is performing well, however, there may be a higher risk of a major failure impacting on the performance of that method, eg the failure of a mass blast of a crown or rib pillar. This paper will present a flowsheet approach to the use of risk analysis for determining the likely production rates of different mining methods. This framework allows the annual metal output to be estimated and from this the NPV for each method. A level of confidence can be applied to the estimated NPV for each option. An example will be presented on how this technique has been used within the Normandy Group.

Jan 1, 1998

By O Ignatenko, A van Schaik

Environmental legislation for the process and manufacturing industries is frequently formulated without considering the fundamental limits of physics, chemistry and thermodynamics within process technology. Recycling of end-of-life goods is used in this paper to show how the limits can be evaluated on the basis of the theory of minerals processing and metallurgical engineering. This theory has been applied on European Union level to re-examine the legislation for automobile recycling in a recent stakeholder discussion involving the automotive industry (http://www.assurre.org). This theory and our models are finding their way into the computer aided design (CAD) tools of the automotive industry, developments that form part of a project to design the super light car of the future (http://www.superlightcar.com). Only such fundamental approaches will in future be able to provide the basis to argue and define realistic and sensible environmental legislation.

Jan 1, 2006

Development of the Davcra flotation cell has continued over the past seven years. Preliminary testwork on single cells has now been extended to a com- plete Davcra flotation circuit, to cells ranging from 5 to 400 tons per hour capacity and to cells operating on a variety of materials. Operation of both test and production units has shown the Davcra cell to be competitive with conventional flotation machines. It offers a lower capital cost installation than conventional cells and in addition has a number of. operating advantages, particularly in its adaptability to automatic control.'

Jan 1, 1971

By G Lane

This paper discusses the factors that contribute to the cost effective design of a concentrator. Concentrator design and layout outcomes are functions of the team (engineer’s and owner’s) participating in each particular project. The benchmark for relatively modest projects was set in the 1980s and 1990s during the ‘gold boom’ when numerous cost effective plants were designed and constructed on a lump sum basis in a very competitive market. A number of factors contribute to lack of transference of the lessons learnt in gold plant design to concentrator design including established paradigms in the design and layout of concentrators, lack of experience in cost effective design, operator’s preferences for flowsheet and layout and simple lack of appreciation of the impact of plant footprint on materials quantities and resultant capital costs.Experiences with recent copper concentrator projects (both small and large) are used as case studies.

Aug 8, 2011

SASOL Synthetic Fuels has recently completed the design of sampling systems for raw and blended coal feeding the gasifiers at Secunda, South Africa. The new systems will replace manual, stopped belt sampling and have been designed to achieve specific accuracy targets on a daily basis. The sampling system is unusual in the coal industry in that the fines content (-5.5 mm nominal) of the coal is very critical and is to be determined with high accuracy.The sampling system was designed to meet carefully considered target accuracies using methods of modern sampling theory. The heterogeneity of the coal streams involved with respect to the critical analytes was determined by appropriate sampling and sample analysis. The statistical characterisation of the time variation of analytes in the process streams was based on variograms derived from on-line ash gauges. From this point, the design was completed using fundamental statistical sampling theory and some simulation studies. The paper discusses the development of the sampling system design in detail as well as the plans to use the data stream to provide timely alarms when the coal quality deviates from the target specification.

Jan 1, 2002

By Young JA, Rogers G, Bannister S, Edwards SA

Many coal mine operators have responded to economic pressures by massive investment in machinery to reduce unit costs. To sustain the increased production which must justify the expenditure it is essential to know the resource in great detail months or even years in advance of its extraction. The required detail includes variations in composition and any lateral disruptions to the seam which night affect production. As Wilson (1985) has pointed out, a day's production loss can mean half a million dollars income forgone, and an unexpected major fault can mean a shutdown of weeks. Traditionally, seams were probed by surface drilling on (typically) 250 or 500m centres, and by horizontal drilling from sithin'the seam. Core was analysed chemically. The new generation machinery cannot tolerate the risk attendant on such widely spaced sampling, but the costs of much closer sampling rapidly become prohibitive.

Jan 1, 1987

By F Shi, G Ballantyne, K Runge

There has been minimal innovation in the methods used to process an ore over the last 50 years. Productivity increases have largely resulted in increased equipment size without implementation of parallel improvements in technology. Complex orebodies of the future will need mining operations to adopt new technologies and techniques to make future ore treatment economically viable. Three emerging technologies, namely high voltage pulse (HVP) pretreatment, fine screening and the HydroFloat<sub>TM</sub> coarse particle flotation cell will be presented in this paper and the potential benefits that may result if they are adopted in mineral processing circuits will be outlined. The barriers that must be overcome before they can be adopted by industry with confidence will also be discussed. CITATION: Runge, K, Shi, F and Ballantyne, G, 2018. New technologies that will potentially enable processing of complex orebodies, in Proceedings Complex Orebodies Conference 2018, pp 126–129 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018