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By A Fowler

The unpredictability of the location, grade and width of narrow-vein deposits presents difficulties for mine geologists and engineers attempting to estimate, schedule, forecast and mine their deposit profitably. This unpredictability stems not only from the grade distribution within a vein, but also the irregularity of vein geometry in three-dimensional (3D) space. Traditional deterministic methods of modelling vein geometry do not account for the inherent variability of the veins, resulting in significant errors when using limited drill hole information. This paper presents a probabilistic method of modelling narrow-vein deposits using sequential gaussian simulation (SGS), which can quantify this variability and improve production forecasts. Vein geometry, thickness and grade are simulated to provide a number of different equi-probable realisations that each honour the drill hole and face sample input statistics. An example is presented from the Augusta narrow-vein Au-Sb mine in central Victoria, where the simulation results are validated against the input data and survey pick-ups of the veins along ore drives.

Aug 22, 2011

By Y Zhou, Y Liu, J-P Yang, P Wang, K Hu

"Large-scale mine reclamation has taken place recently in response to the implementation of mining regulations in China. Effective monitoring of the progress of reclaimed land is a critical procedure to assess the quality of reclamation program and to ensure that mining enterprises fulfill their reclamation responsibilities. The present paper reports a preliminary study that examines the situation of mine land reclamation monitoring. Based on the monitoring, some general requirements for mined land reclamation have been proposed, including: the monitoring should be systematic and comprehensive the monitoring should be adapted to specific local conditions the monitoring should be reasonably optimised via scientific methods and technology the monitoring should stick to a variety of national technical criteria.The aim of land reclamation monitoring is to evaluate changes of critical indicators closely reflecting the development trend of the reclaimed mined land, to develop or improve the criteria and technical parameters specific to the site, and to prevent secondary environmental degradation. Based on these requirements and aim, the monitoring should cover the progress of reclamation, establishment of vegetation and plant community development; and recovery of land and water quality in the reclamation area. Regulatory measures are proposed which would improve the work of mine reclamation monitoring in terms of regulation, organisation and financial support.CITATION :Wang, P, Yang, J-P, Zhou, Y, Hu, K and Liu, Y, 2012. The primary framework for the mechanism of the mine reclamation monitoring in China, in Proceedings Life-of-Mine 2012, pp 47-50 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 10, 2012

By M Ziemski

The provision and management of energy in both fuel and electricity forms is an increasingly important consideration for mines. Pressures from communities, governments and markets are increasing towards more transparent and improved energy management. Combined with the energy-water nexus, where water and energy are closely related in the operation of a mine, this emerging business climate means a more thorough and responsible approach is required for the acquisition and use of energy, as well as the release of emissions. Many of the complexities in potential new ore bodies are borne in remote locations, high altitudes, low grades, arid climates and deep deposits. Each of these challenges affects the successful provision of energy. In combination, such challenges can leave an operation seemingly unviable from an energy perspective, especially when approached from a traditional mining energy feasibility lens. This paper discusses some of the energy alternatives currently available and emerging in the mining industry. Both energy supply and demand options are considered, which can provide a very different energy footprint with the flexibility to address, and potentially overcome, major energy challenges for a mine. CITATION: Ziemski, M, 2018. Energy complexities in complex orebodies, in Proceedings Complex Orebodies Conference 2018, pp 106–111 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 21, 2018

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

Sep 13, 2010

By Y, Li Jianxiong, Hu Hua, Gu Desheng

After having briefed the technical and economical advantages of continuous mass mining in underground metal mines, the authors discuss the four stages of research and development of continuous mass mining in China. The four stages are: vibrating ore drawing in a stope, continuous mass mining in a stope continuous mass mining without rib pillars in an area and continuous mass mining in whole mine. The authors briefly review the research achievements of the first and the second stage; Combining the key national research project of the æNinth Five Year PlanÆ ù æThe experiment and research of continuous mass mining without rib pillarÆ, the authors introduce in detail the technological condition of mining, the design ideas of continuous mass mining, the design scheme of mining, the technology of mining. the equipment of mass mining, the chief research achievements and so on. The success of research of continuous mass mining without rib pillar indicates the arrival of the third stage of research. The introduction of continuous mass mining will promote the technology revolution of mining in China remarkably. The authors also point out that the development direction of continuous mass mining of the 21 century is continuous mass mining in whole mine, which is the fourth stage of research.

Jan 1, 2000

By D Bruggemann, F Sereshki

There has been an ongoing research on coal and gas outburst for the past two decades at the School of Civil, Mining and Environmental Engineering, University of Wollongong. Research study began with a humble beginning, initially conducting basic laboratory studies on the coal and gas properties, progressing into the determination of gas content of coal by sorption technique and the effect of gas pressures on coal strength. The present laboratory facilities and research interests are extended to include the study of coal permeability and shrinkage properties and their effect of gas drainage characteristics with respect to gas type, and pressures. All the changes are examined with respect to changing in-site geological conditions of the coal deposit investigated. The aim is to provide a long-term support to industry in establishing a data bank for Australian coal deposit characteristics and properties.

Jan 1, 2005

Heatings, fires and explosions in New South Wales (NSW) and Queensland coal mines since 1972, are reviewed. Geological and mine settings are outlined. Where available, gas analysis and critical decisions are discussed. This paper updates work by NSW Department of Mineral Resources (1995) and the Queensland Department of Mines and Energy in a report on fires and explosion in Queensland coal mines (Richardson and Ham, 1996). Incident data has important applications in terms of evidence-based risk assessment and identifying key issues to be integrated into competency based training programs. Predictive indicators are reviewed in terms of coal parameters in seams where the incidents occurred.

Jan 1, 2005

By E McLean

The decision making check-list and hierarchy of information for process and plant design is generally wide-ranging and complex. The nature of grades, mineralisation and ore types in an ore body, its mine development sequence, and the body of results from metallurgical and physical test work present complex and competing influences on flowsheet development, values for design, equipment selection, plant efficiencies and operating strategy. The challenge is how to manage all these variables, to understand their impacts on performance, and how best to provide a cost-effective plant design and robust process that meets daily/weekly/monthly operating objectives. Throughput, production and grade or product specifications need to be met. The ore body is not average; its range of metallurgical and physical characteristics may be moderately to highly variable. This paper assesses some of the key competing influences and conflicting issues in design and equipment selection, and their effect on production and performance expectations.

Aug 8, 2011

By T M. Campos, H A. Petit, L M. Tavares, R Olympio

Much practical experience has been gathered in the last 30 years of application of high-pressure grinding rolls (HPGR) integrated with ball milling in size reduction of fine iron ore concentrates. The company Vale S.A, in Complexo de Tubarão (Brazil), was one of the pioneers applying the technology prior to pelletisation with an outstanding size reduction energy efficiency in the circuit and a significant increment in the specific surface area of the product. Recent studies by the authors demonstrated benefits of modelling and simulation to improve the performance of HPGRs in this particular application, with the model being able to describe HPGR performance under different operating conditions and under variations of feed size distribution. Despite these important advances, this modelling approach has only been used offline and under steady-state conditions. The present work applies the modified Torres and Casali model proposed by the authors in pseudodynamic simulations. The ability of the model to predict the characteristics of the product in real-time is evaluated using data available online for the pellet feed preparation circuit. Results demonstrated the model capabilities to map the physical operation and give a realistic representation of the process. Additionally, the model is demonstrated to be able to support the pellet feed production by providing extended real-time information of the process, making it a useful tool for improvement of the operational strategies and process stability.

Aug 24, 2022

By M Bouare, C Holland, K N’Diaye

Two adjacent open pits in Mali hosted by deeply weathered saprolitic materials were mined consecutively over the course of approximately 12 months. During excavation, both pits experienced significant displacement and tension cracking as the result of deeper than expected depth of weathering coupled with relatively steep slope angles and significant groundwater. In response, geotechnical and operations teams overcame numerous monitoring challenges with prisms and radar to develop a simple and effective monitoring system coupled to a Trigger Action Response Plan (TARP) which enabled continued safe operations while reducing ore loss. Observations of previous slope performance of these two pits allowed for greater confidence in empirical failure runout calculations that was used to specify the standoff widths for the exclusion zones in the pit. Back analysis of the slope as-built performance after the first indications of slope distress was also conducted. The back analysis was used to confirm rock mass parameters for modelling while being utilised as a reality check for the stability analysis. The stability analysis indicated that leaving a large step-out or buttress would not prevent the displacement, resulting in some ore being sacrificed to ensure the safety of personnel. Key learnings from this experience highlight the importance of: • up-to-date geological interpretation of the depth of weathering • ensuring slope design guidance is reviewed and updated as latest information (ie geology and monitoring) is received • having multiple complementary slope monitoring methods to ensure redundancy • ensuring visual observations and as-built performance are utilised as a reality check to provide greater confidence in stability analysis and design guidance.

Jun 22, 2022

Miners and explorers in New Zealand are expected to consult with stakeholders, keep out of core conservation areas, and operate a high standard of environmental management and rehabilitation. These requirements are not difficult to meet, but many of the industry's own actions have brought it to a low level of general public esteem in New Zealand. Reasons for this are discussed, drawing examples from the Maruia Society's experiences with the industry since the mid-1980s. The boundary between core conservation areas and other land is not easily drawn, and the Maruia Society has sought to work with the mining industry to promote legislation for net conservation benefit trade-offs. However this initiative was not successful. Today the industry, unlike most other major industry sectors in New Zealand, has no accord with the country's conservation movement.

Jan 1, 1997

By W A. Peck

Raise boring is the preferred option for constructing ventilation shafts in Australia. The trend has been towards larger diameters and longer single-pass shafts, and if at all possible, reaming through to the surface. The risk of raise failures, due to missed, unforseen or latent ground conditions has therefore been increasing, along with the need for better, more confident stability assessments.While the stability of specific weak zones and structures must be assessed individually, empirical rock mass classification schemes have been successfully used for about the last 20 years to assess general raise stability; eg the McCracken and Stacey method (M&S).Unfortunately M&S, as originally documented in McCracken and Stacey (1989), did not include a database of raise diameter and rock mass conditions versus actual performance. Nor was there a procedure for assessing the risk of failure due to adverse ground conditions. Peck and Lee (2008) published an Australian database of raise bore performance. Raise diameter and ground conditions, in terms of a lower bound Qr value, were presented for 50 cases versus raise performance. This paper updates the 2008 raise performance plot with more and SRF-corrected data. McCracken and Stacey (1989) had previously recommended that additional geotechnical data should be acquired and analysed when the proposed raise plotted on the unstable side of raisebore stability ratio (RSR) = 1.3, but the Australian data used in this study also suggests that all sites with Qr Contributions and sensitivities of various rock mass parameters (RQD, Jn, Ja, Jr, Jw, SRF, time-dependent weathering/deterioration) to raise stability and risk of failure are discussed. Numerous case studies are used to illustrate issues with stability assessments.As raises can now be remotely supported using sprayed fibrecrete, questions of time-dependency are also discussed. In recent times, contiguous piles, ‘mini-piles’ and grouting have also been successfully used to presupport or otherwise improve the stability of near-surface sections of weathered, or poor quality rock masses.

Mar 21, 2011

By J P. Moodie

Recent trends in flotation technology are briefly reviewed. These show that considerable development has been made as the operators, suppliers and technologists have responded to the challenges of the industry. Most of these advances have been based on empirical and phenomenological methods. There is a considerable opportunity to make further advances through a more fundamental, scientific approach. Some of this work is discussed and, although progress is being made on this front, industrial uptake has been somewhat slow. A number of specific issues facing the industry are discussed.

Jan 1, 2005

By O N. Savassi

A rigorous methodology for prediction of flotation plant performance is presented, which is based on a standardised batch flotation test called the MFT. The work is part of the FLEET program, developed by MinnovEX with the support of seven large mining firms. The methodology is divided into three key steps: direct measurement of the kinetics of true flotation in the pulp, independent of hydraulic entrainment and other froth effects in the batch cell; benchmarking of the industrial plant over a broad range of ore types and operation conditions; and model calibration to describe froth effects in the plant, with a minimal number of parameters. To date, the methodology has been applied with success at several industrial plants, encompassing copper, gold, nickel, iron, lead, zinc and coal operations. This paper includes a description of the laboratory testwork procedure and scale-up to full industrial circuits. Examples of industrial application are also presented.

Jan 1, 2005

The efficient and profit-maximising daily and long-term management of the Vera Nancy resource depends on decisions based upon assay data. This paper examines the range of sample sources, the methods of sample collection, assay techniques and Quality Assurance used by the mine. The orebody has a relatively low nugget effect for a gold mine (around 25 per cent) and this greatly assists in reducing sampling error and producing reliable assay data for production decision-making. Reconciliation between mine and back-calculated mill grades generally sees the mine under-calling mill grades by around four per cent.

Jan 1, 2000

By B Kilgariff

Flotation has been in use at Broken Hill for nearly 100 years, and the process has gone through many different optimisation studies over that time. This paper reviews the current flotation practice at the Perilya Broken Hill Mine, and details one of the recent optimisation studies conducted using mathematical modelling and simulation tools. The optimisation study consisted of surveys of the lead and zinc circuits, mapping of the floatability components of the ore and developing models of the lead and zinc circuits. The models were then used to conduct simulations to simplify the circuit. The study allowed plant personnel to identify optimum operating conditions for their current flotation cells, as well as possible improvements in circuit configuration and cell capacity.

Jan 1, 2005

By M Grigorescu, J H. Hodgkinson, M Khanal

The mining industry often needs to operate in remote or climatically harsh locations. The industry has recently been forced to deal with extreme conditions including floods, heatwaves and droughts. As these are becoming progressively frequent occurrences, mines typically build ‘downtime’ into production schedules and expect to incur costs to manage the various risks arising from climate extremes. Importantly, many environmental conditions are becoming more extreme and consequently, risk management based on past data can become increasingly ineffective. Market and shareholder demand for fewer interruptions are another pressure on mines to avoid prolonged or frequent downtime. Hence, adaptation to climate is becoming an important strategic move for many companies, many of whom are using future climate scenarios and alternative risk evaluations.We present here a method that uses commonly available mine site data to assist decision-making for reducing vulnerability to sudden flood. The method, ‘climate-related adaptation from terrain evaluation results’ (CRATER), identifies a mine’s flood ‘hot-spots’ and presents them as a ‘traffic lights’ warning map. The process then requires a failure analysis process such as fault-tree analysis to identify both the cause of possible failures and a range of possible failure-avoidance adaptations. In the final stage, management can assess the most suitable option for the mine, based on the availability of capital such as time, facilities, labour and money in addition to social acceptability of the options. CRATER has been tested in an open cut mine environment and is now being further developed to identify how subsidence over underground mines may impact on flooding and ponding over the mining life cycle (CRATER II). Further work is continuing to test larger and more complex mine landscapes to deliver a method to extract more knowledge from existing data.CITATION:Hodgkinson, J H, Grigorescu, M and Khanal, M, 2016. Reducing mine site extreme rainfall vulnerability using climate-related adaptation from terrain evaluation results, in Proceedings International Mine Management Conference, pp 187-200 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jun 22, 2016

By M Jacobs

This abstract discusses a heap leach copper mine that was failing to perform and as a result was not meeting targeted production. The mine had numerous technical challenges including: high water inflows, low levels of geotechnical monitoring, performance issues with mining, resource model and grade control reconciliation issues, and unexplained low levels of performance from the heap leaching operations. A team from various organisations with specialist skill sets including: a forensic accountant, the owner’s representative and a mining engineer, was arranged to visit the site. The task was to investigate the situation and determine what could be done to turn the performance of the mine around. After an initial assessment in late 2018, efforts were directed to better understanding the operations and improving the performance of the site through preventative management. A key part included the creation of production forecasts that could be achieved that would help restore confidence in the operations. Uncertainty in the mine achieving production forecasts and the performance of the heap leaching operations were contributing to the decline of the operations. Investigations uncovered the fact that while the resource model could reliably predict total copper, a lack of sequential leach data meant the accurate prediction of soluble and insoluble copper species, both important for heap leaching, was difficult to do with any degree of certainty. The crushing and mining contractors also appeared to have suffered somewhat from a lack of management by the owner’s team and performance had affected the production of copper. Collaboration and management were used by the team to understand and stabilise the operations. Ongoing collaborative efforts by the management team, site personnel and contractors resulted in a positive outcome for the owners and their mine – and could at yours.

Jun 22, 2022

By I Sucholutsky, D M. First, D Mogilny, F Yusufali

Machine learning is creating value in all facets of the mining industry, from exploration to production. The authors provide an accessible, high-level introduction to artificial intelligence (AI), machine learning (ML), and deep learning (DL); the latter being widely recognised as one of the most powerful forms of ML. In particular, the authors will introduce deep learning models known as convolutional neural networks (CNNs), how they are applied, and the economic considerations necessary for determining when DL may be the right solution to de-risking complex block modelling problems. The authors present preliminary results from the mineral resource modelling study of the Jundee orogenic gold deposit, Yandal belt/gold province, Western Australia. The primary goal was to identify the direction and location of the narrow gold veins more accurately and demonstrate how non-linearly correlated elements are used as direct inputs to the resource model to assist with the target element’s grade prediction. This demonstrates that: (1) existing techniques for finding correlations between assayed elements do not adequately reflect the complex geology of the asset, (2) nonlinear correlations that are difficult to model as simple mathematical functions are representative of geological patterns in a deposit, and (3) non-linearly correlated assayed data, fed as inputs, increase the performance of the resource model as reconciled through blind tests. To conclude, the authors hypothesise that the patterns represented by the DL block models may be revealing the results of overprinting geological processes that generated mineral deposits. For example, the primary hydrothermal processes that deposited metals created depositional patterns that become particularly complex as a result of being overprinted, in part or in whole, by secondary physicochemical processes. This may explain why non-linear geochemical relationships have the capacity to generate more accurate block models of mineral deposits.

May 24, 2023

By W Polkowski, M Tangstad, M Wallin, J Jiao

Fe-26Si-9B (wt per cent) alloy has been identified as a potential high-temperature phase change material (PCM) due to its attractive properties, such as its high latent heat of fusion and low volumetric change during solid/liquid transition. For the successful utilisation of this alloy into thermal energy storage (TES) systems, the development of a cost-effective production method is essential. Presently, the Fe-26Si-9B alloy is produced by mixing FeSi alloys with either pure boron element or FeB alloys. However, the use of pure boron is financially prohibitive, and the carbothermic reduction results in high greenhouse gas emissions and high energy consumption in the production of FeB alloys. In this regard, our study proposes a silicothermic reduction method to produce Fe-26Si-9B PCM by using FeSi alloys and B2O3-based oxides. Accordingly, the influence of various parameters on the production process was investigated, including operating temperature, holding time, B2O3 content in the added oxides, and initial Slag/Metal (S/M) ratio. Based on the experimental results, the optimal parameters for producing FeSiB alloys with over 9 wt per cent boron were determined. Consequently, it was documented that the FeSi alloys and the added oxides enriched with 50– 65 wt per cent B2O3 should be subjected to temperatures ranging from 1550–1650°C, maintain an initial S/M ratio exceeding 1, and ensure a holding duration beyond 1 hr. Moreover, the energy consumption of this process was estimated to be ~1.86 MWh/t metal and the mass loss was lower than 7 per cent. Therefore, silicothermic reduction offers a sustainable approach for producing FeSiB alloys with a boron content above 9 wt per cent.

Jun 19, 2024