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By J A. Braithwaite

Social licence to operate is not a new concept for the mining industry, referring to stakeholder approval or acceptance for the activities and impacts of a project, company or industry. It is intangible, dynamic and non-permanent, hence it needs to be earned and then maintained (Thomson and Boutilier, 2014). It has also been argued that social licence extends beyond building approval or acceptance, into engagement for long-term development (Owen and Kemp, 2012).There are many examples where stakeholder opposition – or withdrawal of social licence – have increased capital and operating costs, extended schedules and impacted reputation. At its extreme, the withdrawal of social licence to operate can also contribute to or be the catalyst for mine closure.The key benefit of obtaining a social licence is a reduction of risk. Stakeholder support and advocacy, as well as the implementation of social performance programs that contribute to social licence, can be beneficial in terms of schedule, costs and other benefits.While decisions to close a mine are generally driven by resource availability or economic conditions, the social, economic and environmental legacy remaining post-closure is of importance to many stakeholders. With a number of significant mines now approaching closure within Australia, we are seeing heightened community concern about the economic and social impact of mine closure and the success of land rehabilitation. So how does the concept of social licence to operate extend into the closure phase of the mining life cycle?CITATION:Braithwaite, J A, 2016. Social licence to close?, in Proceedings Life-of-Mine 2016 Conference, pp 176–179 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 28, 2016

By A Murphy, I Samsonova, N Eastwood, D Whittle

Part XI of the United Nations Convention on the Law of the Sea (UNCLOS or the Convention) (United Nations (UN) Division for Ocean Affairs and the Law of the Sea, 1982) establishes a comprehensive regulatory framework for the conduct of deep seabed mining (DSM) activities of mineral resources in the Area (defined in Article 1(1) of UNCLOS as ‘the seabed and ocean floor and subsoil thereof, beyond the limits of national jurisdiction’). Under that framework, DSM activities can only take place in the Area pursuant to an approved Plan of Work in the form of a contract with the International Seabed Authority (ISA) (the Authority), a 168-member international body created under UNCLOS to administer the Area. Private contractors can undertake DSM activities if they are sponsored by Member States of UNCLOS, providing a dual system of international and domestic regulatory control and oversight for activities in the Area.

Sep 1, 2024

By C Rule

In 2003, Anglo Platinum, in a joint development with Xstrata Technology, installed the world’s first 10 000 litre IsaMillTM in a concentrate regrind duty at the Western Limb Tailings Re-treatment Plant. The success of that installation was the enabling event for Anglo Platinum to proceed with a substantial investment in horizontal stirred milling technology. Since 2006 an additional three IsaMillsTM in concentrate regrind duties and a further 18 IsaMillsTM in the more technically challenging coarse grinding mainstream applications, have been commissioned in group Concentrator operations - bringing the total number of IsaMillsTM installed in Anglo Platinum plants to 22.A collaborative approach between Anglo Platinum and Xstrata Technology towards improving milling efficiency and reducing operating costs, through internal mill component wear optimization and operating recipe development, has resulted in further improvements in the overall success of IsaMillsTM in the flow sheets of many Anglo Platinum operations. The addition of IsaMillsTM in the Anglo Platinum flow sheets has improved plant PGM recoveries by as much as 5%.This paper explores the improvements made to the IsaMillsTM flow sheet and mill internal design and shares some of the operating experience with IsaMillsTM technology in Anglo Platinum

Aug 8, 2011

By L Rachmad

Freeport IndonesiaÆs Deep Ore Zone (DOZ) mine is the new underground block caving mine within the East Ertsberg Skarn System (EESS) deposit which started production in mid-2000. The DOZ will produce 25 000 tpd using mechanised block cave mining method and will be the fourth underground mine opened within the EESS deposit. Evaluations were made on former block caving mines at PT Freeport Indonesia (IOZ, GBT Area I and II) in order to design a more appropriate support system. As a permanent support, the thread bar bolt support system is widely used in the DOZ mine. The advantages of this system are ease of operation, quality control and high bond strength. The main problem of this system is the curing time of about 28 days to achieve maximum strength, necessitating the installation of a temporary support for its implementation. In this instance, the system was inefficient in operation and studies were required to find an alternative grouting system. This paper examines the evaluation of thread bar bolt support system and compares the performance of two types of grouting (resin cartridge and cement cartridge) with cement grouting performance. The evaluation is conducted with a pull out test. The advantages and disadvantages for each grouting method, comparison of cost estimation and grouting application in mine scale are presented in this paper.

Jan 1, 2002

By C Mann, S Swapp

"The mining industry is often challenged with the task of evaluating narrow vein open pit deposits. A realistic mineable solution from optimisation needs to accurately represent mining dilution and the practical limitations of mining equipment. Open pit dilution is driven according to mining method and fleet selection as this dictates the ‘selective mining unit’ (SMU) that can be practicably mined.Common evaluation methods represent dilution by:a mathematical dilution assumption addition of a dilution skin reblocking of the model to an appropriate SMU.This paper will explore an alternative method of applying dilution by adapting an underground stope modelling tool. By considering an SMU as a stope, automatic stope shape creators such as Datamine’s Mineable Shape Optimiser (MSO) can be used to create wireframes for each mining unit over the entire deposit. Using these wireframes, the model can be subblocked and assigned as either ore (inside the wireframe) or waste (outside the wireframe) prior to optimisation.The MSO process considers SMU geometry and a depth specific value-based cut-off. The result is an optimised solution for the deposit based on practical and achievable mining constraints rather than one based on generalised modifying factors.To evaluate the economic impact of the methods above, results have been costed and scheduled and a comparison of operating cash flows made.Citation:Swapp, S and Mann, C, 2016. Optimisation Improvements for Narrow Vein Open Pit Deposits Using Mineable Shape Optimiser, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 50–59 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By H Kurth

High specification Prompt Gamma Neutron Activation Analysis (PGNAA) has been successfully applied to conveyed flows at iron ore operations since 2002 to representatively measure ore quality for improved quality management and process control. While the PGNAA technique has changed little since that time, significant improvements have been made in measurement capability. Elements previously unable to be measured well or at all using this technique are now measurable and one of these is phosphorus. Aluminium and magnesium are also key elements in addition to calcium and silicon in determining sinter basicity in ironmaking. Other elements measured routinely in iron ores include iron, carbon, potassium, sulfur and manganese. The benefits of representative measurement cannot be overstated as iron ore mining operations in South Africa, Europe, Australia, Asia and the Americas have discovered. The technology is applicable to any conveyed flow where elemental analysis in real time assists with quality management, from raw materials in ironmaking through to scrap steel in steelmaking and coal quality for coke-making. Major benefits are realised when raw material processing is optimised and this often includes diversion of material meeting a required quality so it can bypass unnecessary processing. This includes waste rock which can be diverted from a plant feed stream in 30 sec increments or ore that meets product quality being diverted to bypass beneficiation. Analysers are successfully utilised to identify ore types that assist with upgrade optimisation in jig plants; measuring feed, product and discard flows to also account for metal content. Product flows to stockpiles help manage production flows and stockpile qualities for different products and assist in blending ores into trains or ships to confirm specification compliance. Technologies can be used in magnetite processing but are predominantly used in hematite and goethite ore processing operations. The paper details examples of the above applications at various operational sites providing estimates of economic benefit as well as operational improvements.

Sep 18, 2023

By S Ellis

In January 2008 Chirano Gold Mines Limited committed to expansion of the Chirano Gold Project from its existing design capacity of 2 Mtpa ROM ore to a new design value of 3.5 Mtpa. In addition to increased throughput, the design had to contend with increasing ore hardness and competency, while at the same time make cost effective use of existing equipment with minimum disruption to existing production. The solution adopted involved some novel approaches including tertiary crushing and operation of the SABC circuit in overflow ball mill mode and parallel elution with a common acid wash column. This paper describes the approach taken to the design of these elements to achieve a cost effective and safe capacity expansion.

Aug 8, 2011

By N Lima, A Piçarra, L Filippov, I Filippova, M Marques, K Silva

The iron industry produces a considerable amount of tailings per annum, due to its substantial volumes of production. The actual iron ore processing routes require the removal of slimes fractions. In addition to iron oxides and quartz, the iron ore slimes are generally composed of other minerals such as kaolinite and finely dispersed iron hydroxides which impact significantly the performance of reverse cationic flotation. In this study, we propose a two stage processing route that would allow further beneficiation of iron slimes which are not successfully beneficiated, avoiding their disposal as waste. The new amidoamine reagent was tested as a collector in a two-stage route to process two samples of iron ore slimes with d50 close to 10 μm and with high kaolinite content (13 to 20 per cent). The results showed that it was possible to obtain iron concentrate with 66.5 per cent iron and 48.4 per cent mass recovery for a feed containing 48.9 per cent Fe associated with hematite (39 per cent) and goethite (32 per cent). The collector efficiency was improved by mixing with frother for the slimes with higher goethite content of 55 per cent: the concentrate grade was increased from 58.8 per cent to 64.5 per cent with addition of the frother at the expense of reducing operation metallurgical recovery from 87.8 per cent to 75.6 per cent. The efficiency of the process was improved by applying an external energy impact to disperse the fine particles and clean the surface of the minerals. The new amidoamine collector does not require a depressor such as corn starch and may provide the development of new concentration routes for complex ultrafine iron ores. The combination of the amidoamine-based flotation at first stage with high intensity magnetic separation allowed development of optimised two-stage processing routes to valorise the iron ore slimes rejected to the tailings in the actual flotation plant.

Sep 18, 2023

By W Assibey-Bonsu

The paper provides a brief review of the multivariate uniform conditioning and the localised multivariate uniform conditioning techniques and presents a case study based on a porphyry copper gold deposit in Peru. Two other important scenarios have been investigated and will be particularly emphasised: The recovered selective mining unit (SMU)s depend on a combination of copper and gold content, which can be expressed by means of ænet smelter returnsÆ (NSR). Two approaches are compared. Firstly, the application of a composite cut-off on NSR on the joint distribution of each grade and the application of uniform conditioning to three variables is investigated, ie for the first approach NSR is used as the main variable. The second approach considers copper as the main variable. In the case of multiple domains the procedure used to apply the technique to process mixed panels is clarified and recommendations are made.

Sep 26, 2011

The N3500 orebody is the northern continuation of the 3500 orebody at Xstrata Copper's Enterprise Mine and occurs at a depth of 1.3 to 1.8 km. At the nearby S3500 orebody, extreme deformation was observed in access drives where there was a high number of bedding planes per metre combined with either graphite or talc infill. The observed failure mechanism was largely controlled by the geometry of the inclined bedding submitted to high horizontal stresses. Due to the anisotropic strength and deformation behaviour of the shale rock mass, traditional isotropic methods of geomechanical property estimation based upon GSI are not appropriate. A numerical modelling approach, based upon the distinct element codes UDEC (2D) and 3DEC (3D), has been developed to accurately simulate the failure mechanisms and deformation observed in the initial infrastructure surrounding the N3500 orebody.

Nov 25, 2010

By J R BISHOP

Geophysical techniques are being increasingly used down exploration drill holes as deeper and more elusive targets are sought. This paper lists the various methods available and discusses the applications using a number of examples.

Jan 1, 1992

By B Wong, R G. Coleman

In flotation, the selection of the size, number and type of cell for a particular duty depends on two important factors. Firstly, the required flotation residence time and secondly, the physical constraints of how much concentrate can be recovered for a given froth surface area and concentrate lip length. The residence time is influenced by ore type and characteristics such as liberation, kinetics and reagent dosage. The amount of concentrate that can be recovered for a given froth surface area and lip length depends on ore type and other characteristics such as particle size, specific gravity and mineral grade. Residence time is determined through a combination of laboratory-scale test work and design scale-up factors. However the critical froth transport parameters such as froth carry rate and froth lip loading cannot be determined in a laboratory. This is because the froth is scraped during a laboratory flotation test and thus does not exhibit natural behaviour, and it is not possible to scale-up froth transport distance or air rate. These values are generally compared via calculation to rule-of-thumb maximum values to establish if these values will be exceeded by the flotation cell selection.This paper first reviews these critical froth transport parameters and then discusses actual parameter values across diverse operating sites, with varying cell duties, cell sizes and types, orebodies and particle sizes. These values are compared against the industry rule-of-thumb to test the applicability of the rule-of-thumb to actual performance. Options are also presented for adjusting these parameters in operating flotation cells.CITATION:Coleman, R G and Wong, B, 2018. Flotation launder design and the measurement of critical froth transport parameters, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 353–362 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By I Grewal, B Klein

The Knelson Continuous Variable Discharge (CVD) is a continuous centrifugal gravity concentrator for high-mass yield recovery applications. It has four operating variables that enable control of mass yield, product grade and recovery namely: fluidisation water, bowl speed, pinch valve open time and pinch valve closed time. Plant testing of a pilot scale Knelson CVD6 was conducted to evaluate the effects of operating variables on mineral separation. The analysis of operating variable effects has provided a framework for the development of operating guidelines for the CVD.

Jan 1, 2001

By S Grobler, T Fares

Understanding the real utilisation of the available volumetric capacity of a conveyor is key to unlocking latent capacity or ‘debottlenecking’ existing plant. Conveyors are typically designed on the basis of conservative density and ore surcharge angle specifications, and consequently there is often latent volumetric capacity available.Laser scanning measurements of conveyor ore profiles has been undertaken on iron ore conveyors to gain an understanding of the actual surcharge angle and the available edge clearances. Iron ore producers seeking to extract maximum production from their assets have used these measurements to debottleneck existing plant and to revise the design criteria for future plant. The benefit is that latent capacity of existing plant can be unlocked and smaller and cheaper conveyors can be designed for future plant, maximising the return on capital. This paper describes the measurements and results.CITATION:Fares, T and Grobler, S, 2015. Laser scanning of conveyor ore profiles, in Proceedings Iron Ore 2015, pp 549–554 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By J E. Powalisz

Obtaining a representative sample of bulk materials in process industries is critical to providing valid data for process control and custody transfer (valuation). The accuracy of a sample, that is to say how well the sample represents the material in the process, is directly related to how well the process can be controlled and to how much a product may be worth. Sampling accuracy then is in fact related to bottom line profitability.Sampling theory offers information and equations on how to take a representative sample from a process, however, the actual practice of extracting a sample from the process can be more of an art.Key sampling variables include product specifications such as bulk density, particle distribution, material conveyance, practical sampler location, sampler type and sample frequency and volume/mass.This paper discusses basic sampling theory, sampling methods, types of samplers, how to develop a ‘real world’ sampling system and current manual and automated samplers.Key points include ‘practical precision and variance’, material properties, flow properties, direct sampling versus indirect sampling, sampler types and applications.CITATION:Powalisz, J E, 2014. Bulk solids sampling, in Proceedings Sampling 2014 , pp 179–188 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 29, 2014

By M Laxman, A Kundu

After multiple tailings dam failures in recent times, the owner organisations have made increased efforts to step up the governance systems to industry best practise in the design, construction and operational management areas. The measures include but are not limited to, site investigation, rigorous peer review (both internal and external), certification through appropriately qualified personnel and improvement in operational management practises. While a lot of focus is on design and operational practices, the construction stage requires adaptation (both in terms of materials and approved design) and immediate decision making on site. Work undertaken in these areas is mostly irreversible and sometimes poses serious threat to the future TSF raise/ expansion planning and may lead to reduced life of the TSF and additional risk to the Owner.This technical paper will discuss some challenges and highlight the importance of appropriate processes to achieve a successful construction regime. The process will include a robust quality control/ quality assurance process, a team of designer-constructor-owner with suitable skills and technical understandings and robust documentation of the entire construction process from day 1 to the completion of construction.CITATION:Kundu, A and Laxman, M, 2018. Robust construction and quality assurance culture for tailings storage facilities – equally important as robust design and review practice, in Proceedings Mine Waste and Tailings Stewardship Conference 2018, pp 111–116 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 23, 2018

By T Walton, C Perring, M Pepper, G Gerber

The Yandicoogina Channel Iron Deposit (CID) is an accumulation of iron pisolites cemented by a goethite-rich matrix. The Yandicoogina CID’s are found in a palaeochannel that meanders within a broad structural basin of the Yandicoogina Syncline in Pilbara region of Western Australia. RTIO Yandicoogina Mine Geology team contributed to a number of strategies maximising the iron ore reserves mined by Rio Tinto. Two strategies are discussed: the replacement of the Batter-Berm final pit walls by contour dozing; and upgrading the lower grade material to crusher feed. 1. Contour dozing – traditional Batter-Berm pit final wall configuration left kilometre long wedges of ore sterilised around bench margins. Contour dozing final walls (ie dozing of ore down the ore-waste contact) as internally defined by RTIO Yandicoogina Mine Geology (Mine Geology), enabled recovery of additional crusher feed. 2. Upgrade of lower grade material – the lower ore domain (GVL) within the Yandicoogina orebody contains numerous clay pods. Contaminant Al2O3 inherent within clay pods can result in CID material outside of crusher feed grade specifications, causing it to be flagged as ‘internal waste’ in mining models and permanently lost to waste dumps. In 2011, after multiple tests, Mine Geology demonstrated that this material could be upgraded to crusher feed via wet processing. With the support of the RTIO Metallurgical Development team new grade specifications were defined. The resulting material has been used to supplement higher grade ore. While increasing the mining ore output, these ongoing value-adding strategies also promote more sustainable mining via better use of the non-renewable iron ore commodity. The initiatives extend mine life, reduce waste movement, improve strip ratio and increase productivity

Mar 22, 2022

By A Fern, A Hawkes, o, T Vincent

The modern workplace has changed dramatically in recent years with an increased emphasis on the psychological well-being of employees. While adhering to a certain standard of psychosocial safety at work is now not only a moral, but legal obligation in Australia, it begs the question: how can organisations begin to ensure psychosocial safety? A positive psychosocial safety climate is one where employees feel they are psychologically safe, feel supported in their work and are not exposed to work-related stressors that can negatively affect their mental health. Such a climate can help boost productivity and create a more positive working environment. This presentation will provide a twopronged approach to understanding and managing psychosocial safety: pairing a traditional risk assessment with climate measurement. Risk assessments can provide several benefits, including identifying and characterising work-related hazards, identifying the nature and severity of the risks to employees and prioritising necessary interventions for reducing or preventing psychosocial harm in the workplace. However, these assessments can have certain limitations, especially when it comes to capturing some of the less obvious causes of psychosocial harm. Climate measurement can provide valuable insights into employees’ perceptions of the work environment, identify areas of concern that may not have been identified in the risk assessment and help to guide organisational changes that will enhance employees’ psychosocial well-being over time. It will also be argued that climate should be assessed from a broad perspective exploring general, physical, social and psychological aspects of safety climate. This presentation will explore why conducting risk assessments in conjunction with detailed climate measurements is integral to protecting the psychosocial safety of employees in the workplace and demonstrate why employers should view the two approaches as complementary and interconnected. Best practice recommendations will be provided for the risk assessment, climate measurement and psychosocial interventions

Apr 16, 2024

Within the Mt Whaleback open cut mine the integrity of the final pit wall is achieved through careful rock slope design, use of rock reinforecement technology where marginal stability exists and use of controlled blasting techniques and excavation practices. By reducing the effective density of ANFO explosive within blastholes to around 0.2 glcm', and developing standard blast pattern designs for various rock types, blast damage to pit walls has been minimised. Accurate geological prediction is necessary for optimum blast design. Controlled blasting is undertaken where blasting occurs within 90 m of the designed final batter crest and hole by hole assessment of final limit blast patterns is undertaken before pattern charging. Shovels and trucks remove the bulk of blasted and dozed rock material, but due to the mine's variable pit wall slope configuration, bulldozer excavation of some critical design batters has been successfully Implemented.

Jan 1, 1986

By C Mroczek, B Mitchell

Perilya Broken Hill, from its inception, has budgeted for more than 2.0 million tonnes per year from the Southern Operations. This tonnage was planned to come from in excess of 100 stopes per year in a remnant mining environment with numerous mined voids and consequent mining challenges. To mine an average of two stopes per week requires patience, flexibility and detailed knowledge to best manage the potential risks and hazards. The evolution of the Perilya Broken Hill Mine Planning Process has necessitated the establishment of a process to identify and manage these risks during the planning stage in a reliable but efficient manner. This process is to ensure that vital steps for each stope are not missed, and that each personÆs work can be tracked by other members of the team. This paper outlines the planning process from resource to stope closure.

Jan 1, 2005