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Reconciliation involves the collection of tonnage, grade (quality) and contained metal (product) data from disparate and hopefully independent sources. Examples are exploration data, production sampling data from blastholes or drawpoints, and process plant data. These data may be compared by means of ratios (factors). The F1 factor usually relates short-term (ore control) model tonnages, grades and metal content to ore reserves depleted. The F2 factor usually relates received-at-mill tonnages, grades and metal content to delivered-to-mill = production tonnages, grade and metal content. The F3 factor is F1 × F2 and enables a comparison of a mineÆs ability to recover the tonnage, grade and metal content estimated in ore reserves. The F1 factor measures the accuracy of orebody knowledge in the ore reserves to the demarcation of ore and waste by ore control (short-term model). The F1 factor may be used to check and calibrate the selectivity of mineral resource models and/or planned dilution assumed in transfer from mineral resources to ore reserves. The F2 factor enables a check on unplanned dilution entering the ore stream between ore control and the mill. Using the factors it is possible to calculate a monetary value on improvements in the accuracy of orebody knowledge, selectivity and the effects of dilution and ore loss. Reconciliation should be an implicit part of the mining process, and reconciliation targets should be a key performance indicator for well-run mines.

Sep 26, 2011

By D Baas, D Bennett

This paper describes how Brisbane-based PanAust Limited develops process control strategies that are implemented at all operations and are used in functional descriptions for plant upgrades and new projects.The process control strategies are determined by operating management philosophies designed to maximise returns from the company’s assets.The approach is endorsed in the project planning and design phases to ensure facilities and equipment that form the major production assets are fit for purpose and capable of enabling the production managers and operators of the projects to maximise shareholder returns.PanAust’s process control approach has been to develop sets of process control standards which focus on two key areas. The first area covers hardware requirements and architecture, software objectives, control models and individual loop tuning methods. The second area defines control room layout, graphic standards and the alarm philosophy. The application of these standards in a new plant or upgrade decreases the time required to achieve design capacity and optimal performance.The PanAust process control strategy changes the operator’s role from one that controls a number of individual loops to one that sets the control objectives of the processing plant. To achieve optimal performance, all the process areas of the plant are analysed to identify opportunities to improve throughput, recovery and stability. Once a key opportunity is identified, a process control strategy is developed which defines the objective of the control, its functionality and how an operator will interact with it. After development of the control model the operators assist engineers to test and debug it. Once the model is robust, it can then be duplicated throughout the group and developed as a group process control standard.CITATION:Baas, D, Bennett, D and Walker, P, 2014. Developing process control standards for optimal plant performance at PanAust Limited, in Proceedings 12th AusIMM Mill Operators’ Conference 2014 , pp 325–334 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 1, 2014

The early records of hydraulic elevator and bucket ladder dredging in the Clutha River system indicate the success of that era of alluvial gold mining in Otago. This paper briefly reviews parameters of depth and gold grade for alluvial operations. The application of dragline technology is proposed for the economic removal of overburden to target the deeper alluvial gold areas which remain in the Otago region.

Jan 1, 1992

Chelopech Mining EAD and Best Available Techniques for Management of Waste Rock in Mining Activities

Sep 13, 2010

By A Huebner, A Noack

Companies all over the world are very sensitive concerning their IT and network security. In most network connected technical installations and machines however, network security is not taken into account to a significant extent: insecure protocols are run, unencrypted information is exchanged freely and even broadcasted wirelessly and networked machines are accessible via insecure file transfer protocol (FTP).What happens in case of malfunctions of such technical installations? Who is responsible? Who can be held liable in case of accidents? The first computer worm for automation systems (æSTUXNETÆ) (Symantec, 2010) was discovered during 2010.The paper is intended to create sensitivity among decision makers for potential security and resulting safety leaks and points out the current status quo in technical network security. It outlines best practices for secure networking and procedures for remote access and remote software updates on stationary equipment and mobile mining machinery. It describes how to ensure authentic and genuine configurations and software targets and how to ensure secure communication for autonomous and remote controlled equipment. For such equipment in particular, the following statement should apply: æThere is no safety without network securityÆ.

Sep 26, 2011

By M Nagarajan, S Esen

This paper presents three case studies from three surface coalmines. The first case study is from a coalmine where a dragline operates in 60 m wide and 1 km long strips. Typical overburden height ranges from 30 m to 50 m. The base case blast was modelled using an advanced blasting model (Distinct Motion Code – DMC) to establish the baseline using the blasting parameters in use before optimisation. DMC was used to model the alternative blasting scenarios to obtain the following key objectives:the post-blast muck pile profile was required to have an optimum height of ~28 moptimise cast percentageachieve a well-fragmented muck pile for the draglinethe muck pile profile should be appropriate for the dragline entry into the strip.Achieving these objectives would optimise the dragline performance through reducing rehandle and improving advance along the strip. DMC modelling resulted in the following outcomes:the required muck pile profile could be achievedthe cast percentage increased from 21.1 to 25.1 – a four per cent increaserehandle volumes were reduced.Establishing a good quality assurance / quality control (QA/QC) process was essential to delivering a blast that could achieve these outcomes. The blast was fired successfully and the dragline completed the strip approximately two weeks ahead of the time taken for the previous strip.The second case study is from a coalmine where D11 dozers are used to move the blasted material to the spoil. An optimum profile was required for the dozers for this low-cost mining operation. To achieve this, an electronic blasting system (uni tronicTM 600) was introduced to optimise the muck pile profiles being delivered. The new muck pile profiles showed improved cast percentage from 10.6 per cent to 17.8 per cent. The changes in the muck pile centre of mass displacement improved dozer efficiency as a result of pushing material shorter distances to its final position. Dozer productivity (bcm/h) statistically did not change but coal was being exposed at a faster rate.The third case study summarises the results from a site where dozers are used to minimise the total mining cost. Traditionally, excavators had been used on-site with conventional blast designs. After firing the first cast shot, the blasted material was found reasonably well-fragmented. Although dozing productivity hasn’t been quantified on-site, operators were providing positive feedback (easier push) due to the reasonably good muck pile profile suiting to the dozers. This site also realised significant savings with the dozing as compared to their truck/shovel operation.CITATION:Esen, S and Nagarajan, M, 2015. Muck pile shaping for draglines and dozers at surface coalmines, in Proceedings 11th International Symposium on Rock Fragmentation by Blasting, pp 409–416 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 24, 2015

After considerable input from the mining industry, the Canadian Securities Administrators (CSA) finalised National Instrument 43-101: Standards of Disclosure for Mineral Projects. This Instrument, which became law across Canada on 1 February 2001, applies to all technical public disclosure on mineral projects and requires all technical disclosure to be based on the work of a æqualified personÆ (QP). While the QP is quite similar to the Competent Person in Australia there are important differences when it comes to all disclosure. This paper will summarise the main areas in which the Instrument introduces major changes to Canadian disclosure standards on mineral projects including the role and responsibility of the qualified person; the increased requirements to file technical reports; the incorporation by reference of the October 2000 CIM definitions of resources and reserves and additional rules governing written disclosure of scientific and technical information. In October 2001, eight months after the implementation of NI 43-101, the CSA compiled a list of frequently asked questions (FAQs) and CSA responses to assist mining industry participants and their advisors in understanding and applying NI-43-101. This document has been well received by industry. The CSA plans to update the FAQs when further guidance is requested. Two industry committees have been established to provide the CSA with technical advice on the application of NI 43-101. As recommended by the Ontario Securities Commission/Toronto Stock Exchange Mining Standards Task Force, the CSA has established an external industry advisory committee û the Mining Technical Advisory and Monitoring Committee (MTAMC) û to monitor the application of NI 43-101 and advise the CSA on industry and professional developments. The role of the CSA-Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Working Committee on Reserves and Resources is to ensure that the future changes and updates to the CIM Standards can be efficiently and effectively incorporated in NI 43-101. During this first year, the Canadian securities regulators have seen an improvement in the quality of disclosure on mineral projects, which will increase investor confidence in the industry.

Jan 1, 2002

By Haigh J. E

An accurate measure of the earth's magnetic field can be made in a few seconds with the portable proton precession magnetometer. Such an instrument increases the applicability of the long successful method of magnetic prospecting for minerals. As an example of the usefulness of the proton magnetometer, a survey over volcanic rocks near Apsley (Tas.) was made.INTRODUCTIONA completely portable magnetometer whose operation is based on the free precession of polarized protons in the earth's magnetic field, is now available on the market at a price competitive with magnetometers based on the classical physical principles. The ease, accuracy, rapidity, and reliability with which measurements of the earth's total magnetic field can be made with the proton precession magnetometer, led to the try-out of the instrument in an actual field problem so as to evaluate fully the capabilities of the instrument. Such evaluation is important, because the history of magnetic prospecting has shown that whenever significantly improved instrumentation has been introduced, prospecting costs have been substantially cut and many areas in which the prospecting costs were formerly considered excessive in relation to probable returns, have become economic mineral prospects. The proton precession magnetometer offers the possibility of opening up new areas for successful magnetic prospecting.AN OUTLINE OF THE HISTORY OF MAGNETIC PROSPECTINGWhile an outline of the history of magnetic prospecting is not directly connected with the evaluation of a proton pre...

Jan 1, 1963

By W Ward, J Clegg, R Barnes, T Zhong

This paper provides an overview of methods for measuring tunnel deflection and construction’s effects on the surrounding environment during and post construction. It will also review illustrative case studies from within Australia and overseas that are most relevant to local construction conditions. Systems illustrated include; vibrating wire and fibre optic strain gauges, extensometers, load cells and piezometers. A novel system using radar interferometry which requires no contact to the structure will also be investigated.In Australia, the majority of tunnelling activity occurs in urban areas (or in the case of mining in rural area) with limited seismic risk. However, the unexpected movement of tunnels is an important factor for structural engineers to monitor. During construction, monitoring is focused on the performance of the tunnelling lining, the supports under real conditions and the effects on surrounding infrastructure. After construction, monitoring will determine the effect of live traffic loads and can also evaluate the durability and any degradation of the tunnel. The aging of some tunnels or the forces subjected by nearby major construction can directly lead to a decrease in structural stability and deformation.The conventional way of inspecting and monitoring those tunnel movements is to have engineers physically enter the tunnel and carry out the measurement work. Manual techniques include tunnel wall convergence checks or total station measurement. However the associated costs are high and measurement process is difficult as some tunnel areas are inaccessible and the data collection interval is limited by the speed of the operator.Automated sensor networks utilising extensometers, fibre optics sensors or strain gauges can be used on tunnel segments or surrounding buildings. Ground settlement measurement via boreholes or hydraulic monitoring points and remote measurement of dynamic deflection can be taken using microwave interferometry.CITATION:Ward, W, Barnes, R, Zhong, T and Clegg, J, 2014. Sensors and systems for the measurement of tunnel movements during and after construction, in Proceedings 15th Australasian Tunnelling Conference 2014 , pp 209–218 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 17, 2014

By R S. Sing, M D. Yadav, G Udaybhanu

This paper presents the results of the first part of a research project to study the effect of various inhibitors to reduce the spontaneous heating susceptibility of some highly susceptible Indian coal seams. In this investigation 11 inhibitors were chosen and applied at three, five and ten per cent of their concentrations in an aqueous solution for four coal samples collected from four different seams. The susceptibility of coal samples, before and after application of these inhibitors, was determined by carrying out crossing point temperature (CPT) analysis. The findings of this study have indicated that it is possible to retard the tendency of spontaneous heating of Indian coals to a considerable extent by the application of six of the inhibitors studied. Further, these inhibitors were tested in 1:1 combination to study their synergistic effect. Finally the economics of the application of these inhibitors has been analysed and four inhibitors are recommended for field use. These results have direct application to control fire and improve productivity and safety in coal mines.

Jan 1, 2005

Government established and financed the NZ Steel Investigating Co in 1960. Its investigations showed that a steel industry was feasible and desirable based uponNorth Island titanomagnetite ironsands, and charted a route for its establishment. The initial processing used post-1945 preheating and prereduction developments, but later innovative improvements created what was essentially a new New Zealand technology. Of the North Island titanomagnetite deposits: the small ones at Waipipi were best made available for export; those at Kawhia and Taharoa were too remote for the economic siting of a mill; that at Raglan proved too small; while at Waikato North Head three times the requirement of 50 million tons of concentrate were located in two sand areas averaging 18 per cent titanomagnetite. Economic studies showed that a South Auckland site would be ideal, close to New Zealand's biggest market. The mill site, on a basalt flow at Glenbrook, was located by a half-day's fieldwork - near both the Waikato North Head deposit, and a railhead for bringing in Waikato coal, etc, and taking out steel products.   This development was one of several since World War II which altered significantly the lives and homes of New Zealanders (others were natural gas, oil, geothermal power, epithermal gold, aluminium, opencastable lignite, etc). All had the essential ingredients of the highest government backing, direct or indirect government finance, and first-class New Zealand scientific and engineering skills (eg to create new technologies). Not one such project failed.

Jan 1, 1993

Gekko Systems Pty Ltd have developed the Python Underground Processing Plant for the concentration of gold and sulfide ores. The Python plant has an established flow sheet including fine crushing, screening, gravity separation and flotation which aims to concentrate the valuable minerals (gold/sulfides). The aim of the plant is to achieve high valuable recovery into a mass yield of 10 - 30 per cent to reduce the amount of material that is needed to be taken to downstream processing. This paper examines the test work protocol for testing an ore to assess its suitability for the Python flow sheet. This paper will discuss the test methods employed to determine crushing requirements, continuous gravity recovery and flotation performance and how the results relate to Python design for the comminution, gravity and flotation circuits. Results from past test work will be discussed.

Aug 1, 2010

By T J. M Harvey

This paper gives an overview of the ASHRAE LibHuAirProp, CoolProp and REFPROP software packages. These packages were predominantly developed for heating, refrigerating and air conditioning engineers and the refrigeration and steam power industries, although CoolProp and REFPROP also cover combustible gases. The main aim of this paper is to highlight the existence capabilities and status of the different packages and where they can be used. The paper gives typical examples of the use of these software packages, specifically as Excel add-ins, and provides a comparison of results of typical mine psychometric and gas drainage calculations using the packages and more traditional ventilation and gas drainage calculation methods. The paper also introduces a hybrid method that improves accuracy compared to traditional methods. In typical mine situations, the use of software packages is probably not required; however, with the increasing accuracy of instruments, potential greenhouse emission costs and the sale of mine gas, more accurate measurements and calculations can potentially save (or make) significant sums of money.CITATION:Harvey, T J M, 2015. The use of psychometric, thermodynamic and transport property software in mine ventilation and gas drainage calculations, in Proceedings The Australian Mine Ventilation Conference, pp 201–210 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 31, 2015

By N Redwood, N Fowkes, A Bassom, S Durkin

"It is well known that from time-to-time a vehicle will interact with a bund or windrow and often the barrier is insufficient to safely arrest that vehicle. The result of such an incident is often catastrophic. Regulations around the requirement for edge protection near pit edges vary between jurisdictions. Generally in Australia regulations tend to be around placing the responsibility on the mine operator to provide ‘adequate’ or ‘appropriate’ edge protection. Guidelines often place a minimum height of bund at between half and two-thirds the diameter of the largest tyre on-site.Safescape has identified the opportunity to improve safety in open pit edge protection and is currently developing the Edge Protector (EP) product. The EP is designed to create a vertical front face to a conventional broken rock safety bund. The fundamental premise of the product is that by creating a vertical front face to the bund, trucks cannot easily drive up over the bund and instead have to push through the rock to get to the other side.In addition to providing a safer system for arresting vehicles, the vertical front face also means that extra space is made available in the haul road. This can either be used to facilitate larger trucks or when designing a new mine, with an increase in overall pit slope.This paper outlines the research and development of a new edge protection product. Discussion will include project objectives, economic incentive for mines to apply the system, mathematical analysis of the truck/bund interaction and physical testing of the product.Citation:Durkin, S, Fowkes, N, Redwood, N and Bassom, A, 2016. Innovative Approach to Open Pit Edge Protection, in Proceedings Ninth AusIMM Open Pit Operators' Conference 2016, pp 138–149 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 15, 2016

By S R. Green, G D. Corder

The legacy issues from mining can, and have often, extended well beyond the closure of operations. However, conventional cost-benefit analysis provides little incentive to implement initiatives at the project development stages of a new mining project as the costs that will be incurred towards the end of the mine life, 20 years or longer, appear minor in net present value (NPV) terms. This analysis can be misleading as the true costs of managing post-mining land can continue for many years, or decades, after mining ceases and any resulting unfavourable legacy issues can delay or prevent government permits or licences to develop new resources. Proper upfront planning is critical for implementing successful rehabilitation and closure strategies. The investment in this planning needs to be done in a structured and rigorous manner taking into consideration the long-term and broad benefits of sustainable land uses after mine closure. The advantages of such an approach could include the streamlining of regulatory approvals by early advice to the regulator of identified issues and responses to those issues, and clear evidence that a strong social licence to operate ethic with local, regional and national benefits is included in the decision-making process. This paper investigates the potential closure options for two case studies at the early stages of project development - concept and prefeasibility. By using a sustainability framework that can identify opportunities and risks, prospective initiatives that deliver enhanced environmental, community and social benefits will be compared with compliance-orientated approaches. This comparison is made across the Five Capitals Sustainability Model - natural, human, social, manufactured and financial. The results of this analysis demonstrate that upfront planning during project development and due care and effort during the life of the working mine will reduce the risks of long-term detrimental legacy issues. This will ultimately benefit the mine operator, the local community and the state.CITATION:Corder, G D and Green, S R, 2012. Using a sustainability assessment framework to achieve enhanced legacy outcomes, in Proceedings Life-of-Mine 2012 , pp 311-318 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By R Jacobs, J Yeates

"The Stockman base metals project is situated in State Forest in the alpine area of East Gippsland, Victoria, adjacent to a National Park and within the headwaters of a major Ramsar-listed wetland catchment and the Murray-Darling River system. Site topography is steep, and elevated (650 m – 1200 m above sea level), and subject to circa 1 m annual rainfall, with occasional winter snowfall. The project consists of two volcanogenic massive sulfide (VMS) deposits to be mined by underground methods and treated in a 1.0 Mt/a central concentrator to produce copper and zinc concentrates for export over a ten year operational life. New resource projects are rare in Victoria. Recognising the sensitive setting, planning for the Stockman Project, which is now in the advanced permitting stage, has focused on balancing economic, environmental and social outcomes to ensure social licence to operate is secured and can be maintained. This has involved close attention to triple bottom line (TBL) risks and outcomes. Stockman has successfully gained State and Federal approvals via the Environmental Effects Statement process. The process of obtaining these approvals has required close attention to effective stakeholder involvement, and management of a lengthy and difficult approvals process, which is still to be finally concluded. This paper is a case study of the process of that permitting and the issues encountered to date. Key learnings from the experience have included: successful approvals require close attention to much more than just the project and its technical aspects and physical setting – effective stakeholder involvement and endorsement is critical the differing consultation requirements for local, regional and government stakeholders, to design and plan implementation of a project to meet TBL objectives, and to gain social licence to operate within the Victorian approvals process, the need for an effective lead government agency with policy authority dealing with material policy change requiring post-closure financial sureties estimating realistic permitting time and cost during the project evaluation phase. CITATION: Jacobs, R and Yeates, J, 2016. Stockman base metals project – sustainability, social licence to operate and permitting lessons learnt, in Proceedings Project Evaluation 2016, pp 98–110 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 8, 2016

Large deposits present computational challenges to todayÆs commercial orebody modelling systems that are based on conventional block models. We describe a system that is specifically engineered to model and visualise large deposits. Central to the system is linear octree encoding of conventional block models and real-time conversion of three-dimensional (3D) meshes to linear octrees. We provide both methodological treatment and practical experience in implementing such a system. A commercial implementation is also presented to demonstrate the validity of the approach.

Sep 26, 2011

By M S. Tuohy

Poorly judged or under-appreciated change plays a role in many major accidents. In particular, operational changes related to continuous improvement, maintenance and introduction of new technology can lead to unintended safety (and other) consequences. This paper provides an overview of the role of management of change in preventing unwanted impacts on safety, community relationships and the environment. It draws on a range of incidents covering mining, minerals processing, refining and smelting where inadequately assessed or ineffectively implemented change led to significant safety, environmental or community consequences. The paper will also highlight cases of well-managed complex change and the underlying model of decision-making in place to make those decisions. All these examples are drawn from Atturra’s experience in response to accidents or working with sites to improve their management systems. The paper will report on the challenges of applying conventional risk assessment approaches to complex or technically significant change. These typically result in either onerous and lengthy change procedures that are prone to workarounds or poor implementation. Conversely, ‘light touch’ or efficiency driven change processes present the risk of intended consequences by failing to bring appropriate expertise to bear in decision-making. Such balances can be resolved by considering the designation of ‘technical authority’ with appropriate expertise to consider the change and deconflict any production, cost or schedule trade-offs. Finally, the paper will reflect on the key components of management of change systems in the context of major accidents, highlighting good practice in how they are implemented. This will consider the integration of existing corporate processes, risk management and organisational structures into management of change systems, not just the content of change forms and procedures.

Apr 16, 2024

Comparing Energy Efficiency of Multi-Pass High Pressure Grinding Roll (HPGR) Circuits With increased emphasis on reducing costs and carbon emissions in mineral processing, it is becoming essential to employ the most efficient comminution devices and to use them to maximum effect. High pressure grinding rolls (HPGR) are considered highly efficient compared with other devices, however their relative efficiency in multi-HPGR circuits is less well understood. A series of comminution tests was carried out to evaluate three multi-pass HPGR circuits and a jaw crusher-ball mill circuit. Combinations of HPGR units (1.0 m and 0.25 m diameter), jaw crushers and Bond ball mills were used to grind a 32 mm top size porphyry copper feed (BBWI = 12.1) to a product P80 size of about 150 ¦m. Up to three passes of HPGR were used in each circuit, with energy measurement and size analysis at each point in the comminution process. The energy efficiencies of individual comminution stages and of the overall circuits were quantified and evaluated using three different approaches. The operating work index method for comparing comminution energy efficiency underestimated HPGR performance due to the large amount of fines generated. The -75 ¦m efficiency factor and F50/P50 reduction ratio interpolation methods both give a fairer measure because they better take into account the amount of fines generated by HPGR. The results show that the relative comminution efficiencies of the three multi-pass HPGR circuits tested differ by as much as 22%, providing insights as how to best employ HPGR in a comminution circuit. The most energy efficient of the circuits tested was a three-pass HPGR circuit with a 1.0 m diameter roll on the first pass in closed circuit with an 8 mm screen followed by a second and third pass in a 0.25 m roll.

Sep 13, 2010

The Savage River open cut magnetite mine is located in rugged terrain in densely rain forested northwest Tasmania. The mine and concentrating plant are both in the Savage River valley. Pickand Mather Incorporated (PMI) operated Savage River as an open cut magnetite mine between 1966 and 1996. Acid rock drainage (ARD) was first noted in the last ten years of the operation, leading to elevated concentrations of heavy metals downstream of the mine. When operations ceased in 1996, PMI returned the mine to the Tasmanian Government along with a remediation fund of $11.4 million. At that time, the assessed cost of remediation was in excess of $120 million. As a result of the ongoing ARD contamination and to facilitate both a new operation and effective remediation, Goldamere Pty Ltd negotiated an agreement with the Tasmanian Government in 1996, which resulted in the Goldamere Act and the Goldamere Agreement. The agreement has allowed Australian Bulk Minerals (ABM) to remediate the Savage River mine in conjunction with the Tasmanian Government while re-invigorating a previously closed mine by providing ABM with an indemnity against past pollution. ABM can configure its mine and waste planning activities to maximise remediation benefits without fear of future litigation for past mistakes. The effect to date has been the development of a long-term strategy to remediate the Savage River and short-term remediation works such as water management, which provide benefits to the ecosystem. After five years, the Savage River is no longer significantly impacted by ARD for 30 kilometres downstream and trout are now reported within the reaches of the mining lease. The arrangements between ABM and the Tasmanian Government are an example of a genuine WIN WIN situation where co-operative environmental management of the site results in significant improvements and where the æregulatorÆ and the æminerÆ are working together to achieve mutually beneficial goals. The end result is a significant benefit to Tasmania.

Jan 1, 2003