Search Documents

By J Holdsworth, L Sutton, A Lavrinec, D Ilic

Air quality is a big topic of discussion in regional mining communities as well as urban environments situated close to port terminals handling bulk solids. Community perception of poor air quality can significantly affect the reputation of the mining operation and handling facilities. Dust monitoring for regulatory compliance relies on using a handful of accurate but very expensive sensors, usually situated at the boundary, relatively far from the activities that generate the airborne dust. These reference monitors measure dust leaving the site but dust mitigation and management on-site largely relies on operator judgement. At a fraction of the cost, small wireless solar powered units can be used to supplement reference monitors in real-time. Due to their compact nature, portability and low price, these units can be implemented on a mass scale to increase spatial resolution of dust measurements and, more importantly, in much closer proximity to both the dust generating activity and the sources of dust. This can provide valuable insights into the origins and timing of dust generation thus producing datadriven decision-making while minimising subjectivity. Similarly, light detection and ranging (LiDAR) is another supplemental technology that can be used to increase the spatial resolution of dust measurements in near real-time, however, the cost of commercial systems even exceeds that of regulatory monitors. LiDAR also presents difficulties in quantifying dust plume concentrations. This study presents learnings of implementing both technologies for dust emissions management. Several low-cost sensor units and a fast-scanning custom-built 3D LiDAR system operating at a range of 1.5 km with a resolution of 1.5 m were deployed on a surface mine to monitor dust emissions from different activities. The project explores the use of real-time sensor data to quantify LiDAR measurements in parallel with integration into mine planning. The approach can assist in prioritising dust mitigation activities thereby reducing instances of emissions exceedance and minimising water use through databased and targeted application. Demonstrated is an opportunity for a step-change in industry best practice as well as commercialisation and operationalisation of the method across different industries, including future mineral extraction.

Sep 18, 2023

By B Patterson, Y Lanwin

Over the last decade the adoption of autonomous technology has proven its potential to fundamentally alter the mining industry, offering significant improvements in safety and productivity. Automation levels are now increasing exponentially across all parts of the supply chain from drilling, haulage, processing, rail and shipping to the maintenance of the above. However, the management of human error risk is also becoming increasingly complex as the disconnect between the people who operate and interact with mining equipment and those that design the autonomous systems grows in terms of skill and expertise. Furthermore, as comfort levels with automation increases amongst operators, complacency is increasing as the initial functional safety benefits have been realised. This paper introduces an innovative concept that unites two distinct fields, functional safety and behavioural economics, to address the complex issue of human error risk in autonomous mining operations. Functional safety, a well-established field in engineering involves identifying potential hazards, assessing risks and designing systems in a way that minimises the chances of accidents and limits their consequences. Meanwhile, behavioural economics takes a data centric approach to analysing the psychological aspects of human decision-making, acknowledging and seeking to understand the errors that can originate from cognitive biases and heuristics. This paper seeks to bridge these domains by emphasising that human error in autonomous mining is not solely a technical issue but is deeply influenced by human behaviour and decision-making processes. By incorporating insights from behavioural economics, we can better predict, prevent and manage human errors in the mining sector. By applying principles from both disciplines to a recent incident example we will explore how cognitive biases can impact peoples’ interactions with autonomous mining equipment. This interdisciplinary approach will not only enhance the design and implementation of functional safety measures in mining but also lead to the development of people centric solutions that consider the inherent fallibility of people. We will explore how human centred design can help bridge the gap between these two domains and apply systems thinking for a universal approach. Through an indepth case study analysis and empirical data, our research aims to provide actionable insights and practical recommendations for mining industry professionals, regulators and stakeholders involved in the safe integration of autonomous systems.

Apr 16, 2024

By S Nowosad, A Binder, O Langefeld, M Bothe-Fiekert, F Apollo

The mining industry faces complex and urgent challenges driven by an increasing demand for raw materials, and a socially demanding globalised world. The extraction of primary raw materials is today more important than ever as one of the cornerstones towards a sustainable future since the increasing demand for the raw materials required for the energy transition. In the last three years, leading countries as USA, China, Canada, Australia, and the European Union (EU) have developed and adopted strategies to enhance domestic extraction capabilities, diversifying sources, fostering innovation in recycling, and promoting international collaboration related to critical raw materials. On 2022, the Inflation Reduction Act was signed into law in the USA, in June 2023, the Australian Critical Minerals Strategy 2023–2030 was published and in March 2024, the Council of the EU adopted the European Critical Raw Materials Act. On the other hand, raw materials extraction is facing higher environmental and safety standards and regulations, as well as scrutiny from the broader public. Regrettable environmental accidents as tailing dam failures or acid mine drainage occurrences have led to a general distrust of mining activities leaving mining companies with the dual imperative of increasing output while implementing sustainability, decarbonisation, and circularity as a core value in their production processes. This challenging environment offers the opportunity to enhance ‘blue mining’ (BM) as a sustainable holistic approach that integrates the principles needed to plan sustainable, reliable, and responsible mines for today’s and future generations by implementing the principles of circular economy (CE). This requires a fundamental shift from the traditional linear economy approach to a sustainable, circular economy strategy. At its essence, BM encapsulates four crucial aspects – energy, ergonomics, water, and circularity and integrates these four aspects into integrative mine planning, defining clear goals and objectives from the ‘blueprint’ of a mine towards a beneficial post-mining activity. Its implementation can lead to maximisation of resources beyond the life of the extractive mine and sustainable use of materials by integrating the principles of circular economy and multiuse mine, see Figure 1. These concepts complement and recognise the need to minimise environmental and social impacts while advancing economic development. Finally, this contribution explains the requirements and challenges of moving from linear to dynamic planning approaches under the BM concept. This way, BM stands as an approach that can contribute to the mining industry receiving necessary approvals and support from society leading to a long-term transformation of the industry’s image.

Sep 1, 2024

By D Connelly

Quartz deposits are common in nature but the presence of quartz suitable for yielding high purity quartz is exceedingly rare. This paper describes a test work study on producing high purity quartz (HPQ) product to meet the tight product specifications of greater than 99.97per cent, including four and even five nines, for uses including, lighting and fibre optics and modern-day high efficiency solar panels. Due to demand in renewable energy applications the market for high purity silica solar panels known for their increasing efficiency and durability is rapidly growing. Demand continues to rise for the use of high purity quartz in semiconductors, electronics, imaging and sensor markets. Microelectronic components are created by chemically fabricating wafers of semiconductors such as silicon to obtain the desired transport of electrical charge and control of the current. The production of silicon metal from high purity quartz has been designated a Strategic Mineral by the European Commission and by the US Department of Justice due to the growing significance of this metal in various industries. The subsequent processing of quartz is the key step to adding value and aiding technological advances. Overall, the high purity quartz market is a highly secretive, specialised market with increasing opportunities for stakeholders. The attempt to produce HPQ in this work was carried out using an Australian quartz ore following a typical HPQ process flow sheet. The unit processes included primary crushing, scrubbing, magnetic separation, flotation, acid leaching followed by hot chlorination. The results indicate that grinding of quartz requires specialist equipment due to the hardness and extreme abrasiveness of the ore leading to additional iron contamination in the ground ore. The critical impurities were aluminium, iron, sodium, potassium, lithium, titanium, zircon, calcium and magnesium. The chemical refining was found effective. The hot chlorination process needed to be done at 1200°C in a chlorine – hydrogen chloride gas atmosphere. The risk of any gas being released during this stage is very serious and only specialist companies should and can carry out this step. More recent studies reported many new options that appear to facilitate the production of HPQ with the requisite purities more easily, but costly equipment along with highly trained operators are required and hence unlikely to become available in standard metallurgical laboratories any time soon.

Sep 1, 2024

By M Hassall

There is a plethora of activities that have been, and continue to be, performed to improve the health, safety and well-being of workers involved in resource industry activities. These activities include implementation of risk management systems, performing risk assessments, constructing bow-ties, implementing critical control management systems, undertaking personal, process and functional safety initiatives, implementing psychological and physical health as well as industrial hygiene programs. Despite the significant work that has occurred over the last several decades, unacceptable levels of fatalities, injuries and illnesses continue to persist as evidenced by Safe Work Australia statistics.

Apr 16, 2024

By M Yahyaei, P Knights, M S. Kizil, J Qu

Digital Twins (DTs) are transforming business operations across many industries through their accurate representations of physical entities enabled by IoT technologies.

Sep 1, 2024

By G McCullough, J Bassan, d P. Knights, C T. Farrelly

By 2045, carbon-neutral mines will be economically producing products that are vital for the world’s transition to renewable energy. After overcoming significant technical challenges (and the investment of significant capital), leaders have successfully eliminated the use of diesel and other fossil fuels by introducing a wide range of new decarbonisation technologies. These leaders will be reaping the benefits of lower production costs (resulting from elimination of diesel), stable and predictable operations, and easier access to capital for their future projects. This paper describes a future scenario of how a net zero carbon and zero-entry mine could operate by taking maximum advantage of technologies in development or already proven in other industries. Some miners have been unsuccessful in their efforts to reach decarbonisation targets. Instead, they have been forced to close or offload their assets to be acquired by operators with better sustainability credentials, or, in some cases, to indigenous or community-based enterprises with vested interest in making operations viable and sustainable. Regardless of ownership structure, all successful mining operations will have fostered strong and positive community relations that bring education, health, security and economic development opportunities to the communities while respecting their traditions, land-uses and culture. As shallow, easy to mine deposits have become scarce, the majority of new mines are underground. Advancements in electric underground technology and the feasibility of ‘zero entry mining’ (with no personnel in active mining zones) has made it increasingly possible to economically operate underground mines, even at shallow depths. The newest mines have a near zero footprint on the surface, produce no harmful by-products, and are employing in-place or in situ methods of extraction that are efficient and low impact. Surface land-uses, such as agriculture and renewable energy generation, continue in the immediate vicinity of the mine, with no significant ground disturbance, community impact or environmental footprint.

Sep 1, 2024

By B Y. Luan, Y Tian, W Zhou, X Lu, Q X. Cai

The unmanned driving technology in open pit coalmines is an important technology that relies on innovation to drive the development of the open pit coal mining industry in China’s transformation of growth drivers and industrial structure upgrading. It is an important path to solve the shortage of mine truck drivers in the future mining, an important way to improve the working environment of open pit mining personnel, and an important foundation for achieving flexible production capacity in open pit mining to cooperate with the coordinated development of new energy. The communication rules at intersections are key to ensuring the safety and efficiency of unmanned driving in open pit coalmines. This paper proposes a collaborative traffic strategy between unmanned trucks for the single bucket unmanned truck intermittent process system in open pit coalmines. Based on the gap theory, this paper analyses the conflict characteristics and establishes a coordinated traffic strategy for the common intersection and merging conflicts of unmanned truck trucks in open pit coalmines, A multi-agent system simulation platform was built to evaluate the coordinated traffic efficiency under different initial average gap sizes of vehicles, with intersection traffic density, vehicle speed, and gap changes as key indicators. The results show that under the simulation conditions of this article, when the initial average gap of vehicles reaches three (four) times or more of the safe distance, the coordinated traffic performance of intersection conflicts (merging conflicts) is better, and the traffic capacity of intersections is close to the traffic capacity without conflicts.

Sep 1, 2024

By T Baumgartl, A Costine, B Boshrouyeh, M Edraki

In mineral processing, the management of tailings may become increasingly more challenging with a change of ore type and the quality of water used in the plant. This, in turn, may affect the overall costs of the operation and water usage and, in the long-term, pose challenges for mine closure and rehabilitation. Depending on the applied treatment technique, the short and long-term properties of tailings are largely determined by the fine particles. Most clay materials and ultrafine particles exist in tailings from oil sands, coalmines and base metals, bringing about challenges in dewatering performance. Moreover, given the growing concern for water scarcity, the minerals industry is increasingly turning towards the use of saline water, which poses yet another challenge for tailings management. The high salt content alters the behaviour of clay particles, making dewatering a more complex process than in freshwater systems (Boshrouyeh Ghandashtani et al, 2022; Costine et al, 2018). High-density techniques for tailings management have been used for several years in the mineral industry. In this regard, one of the novel and promising dewatering methods is in-pipe or inline flocculation, where the polymer is added at high dosages to thickener underflows, giving additional (likely denser) aggregation, releasing more water on deposition compared to low solids thickening. Previous research in the field of flocculation has primarily focused on the process of flocculation itself, specifically the settling rate and size of aggregates, rather than the long-term impacts of the produced tailings materials (Liu et al, 2020; Jeldres et al, 2017). This is particularly true for the novel method of this technology, where polymer is added to the thickener underflow. Furthermore, these studies have used small-scale set-ups using buckets/beakers, plungers and mechanical stirrers for the flocculation process. Unfortunately, these methods lack the necessary control over the properties of the treated tailings, which can lead to irreproducible mixing and dispersion of viscous polymer solutions (Fawell, Costine and Grabsch, 2015). Consequently, a system that can work with a wide range of operational conditions for high-solid tailings material is essential for reliable and reproducible results. The objectives of this study were to determine the effect of different type of polymers in the presence of monovalent and divalent salts on the inline flocculation of artificial tailings. The next step was to evaluate the impact of high-dosage polymer addition on geotechnical properties such as settling rate, consolidated density, rate of consolidation and the hydraulic conductivity of tailings. In addition, this research aimed to fill a knowledge gap and investigate the feasibility of using polymer-treated tailing in removing the copper ions and then quantify the performance of produced aggregates under time-dependent processes.

Aug 2, 2023

By G P. S Resende, D E. G Oliveira, E A. S Baeta, T F. Bravin

There is currently in the mining industry, as well as in other industries, a movement seeking to increase investments in decarbonisation processes to help combat global warming. Among some initiatives taken is replacing diesel-powered mobile equipment in the mines with electricity-powered equipment, such as electric off-highway trucks or even belt conveyors in the mining operation. Samarco is a Brazilian mining company that since its conception has used a conveyor belt mining system in its mining operation, using only a small number of trucks to complement the mining process. This mining process that combines conveyor belts and trucks has brought environmental gains for the company since the environmental impact of conventional truck-only mining is greater than that of the combined system. To measure these gains, a medium-term mining plan was developed in which two fleet scenarios were detailed. One scenario contemplated a high level of detail of belt mining seeking its maximisation, while the other considered the operation performed 100 per cent by trucks, eliminating the use of conveyor belts. Through the comparison of these two scenarios, it was possible to make an inventory of atmospheric emissions and greenhouse gases for each one of them considering data such as types of equipment, diesel consumption, total distance travelled and energy consumption. The results showed that the fleet scenario with conveyor belts results in periods with up to 15 per cent less greenhouse gas emissions and 37 per cent less total particulates compared with the truck-only scenario. Therefore, the results confirm the environmental benefits of the method and the need to look for ways to even expand it in future operations through a study to identify the potential areas in the long-term mining plan.

Sep 18, 2023

By C Hoffmann

Given that each year, 30–40 per cent of mining industry deaths are attributable to failures of vehicle interaction controls (EMESRT, 2023), the mining industry is now armed with a growing body of knowledge from EMESRT (Earth Moving Equipment Safety Round Table) and ICMM (International Council on Mining and Metals) global vehicle interaction initiatives over the past years, that enables mining companies, OEM’s and technology providers to work together to develop and implement more effective controls and drive the adoption of capable solutions. Leveraging 20 years of experience as a global technology provider of Proximity Detection System (PDS) and Collision Avoidance System (CAS) solutions for surface mining operations, Wabtec Digital Mine Technology shares key insights for ensuring the effective selection, implementation and integration of these technologies into existing mine site controls and mining operations for effectively reducing vehicle interaction risk enabling mines to drive towards ‘zero-harm’ objectives. Topics covered include: alignment with industry best practice for controlling vehicle interaction risk by EMESRT and ICMM, importance of the maturity of EMESRT levels 1–7 vehicle interaction (VI) control framework, managing expectations that PDS/CAS is a ‘silver bullet’, alignment with industry functional – performance – technical requirements, proximity detection versus collision avoidance, sensor performance and fusion and limitations, rules engine intelligence critical to mitigating nuisance alarms during normal operations, system health monitoring and reporting, human factors engineering and operator acceptance, implementation strategy, installation standards and quality control, change management program, training programs, reporting and data analytics with actionable insights and maintenance strategies. Insights will also be provided on the challenges moving from EMESRT levels 7 (operator awareness) and 8 (advisory controls) to level 9 (intervention controls) as it’s a journey not an out-of-box solution, the growing demand for coexistence of CAS and Autonomous Haulage Solutions (AHS), functional safety approach, value added systems integration and the applicability of new emerging technologies.

Apr 16, 2024

By C R. Ure

To substantially reduce, if not eliminate, carbon dioxide (CO₂) emissions from ironmaking it is necessary to convert from blast furnace (BF) ironmaking using coking coal as the reductant to direct reduction (DR) ironmaking using hydrogen (H₂) and green electricity. Currently, almost all natural gas (NG) based direct reduced iron (DRI) production utilises iron oxide pellets in shaft furnaces, as opposed to fines in fluidised beds. Also, these pellets are ordinarily produced from high-grade magnetite concentrate, rather than hematite and goethite with typically higher gangue contents. The use of high-grade magnetite concentrate is driven by the preference to melt DRI in conventional electric arc furnaces (EAFs), thereby avoiding the basic oxygen furnace (BOF) for making crude steel (CS). However, in replacing BF with DR ironmaking it is not economically feasible to source enough high-grade magnetite to replace the lower grade hematite and goethite currently consumed. That is not to say that hematite and goethite, or even low-grade magnetite, cannot be used in DR ironmaking. However, their higher gangue content, resulting in higher slag production, requires that the EAF producing CS be replaced with a submerged arc furnace (SAF) that will produce pig iron (PI) for the BOF as does the BF. Here, critical issues to be addressed are, what are the technicalities in replacing high-grade magnetite concentrate with hematite and goethite and NG with H₂ in DRI pellet production and melting? This paper summarises certain relevant published information on DRI pellet research, test work and production together with relevant information on Pilbara ores. It attempts to illustrate the inter- relationship of composition and processing conditions on DRI pellet properties. It is intended to serve as a rudimentary guide to understanding the complexities of formulation, testing, evaluation, production and goethite and offer insight into this challenge.

Sep 18, 2023

By H Arvidson, V Chamberlain, J Joughin, N Pollock, F Cessford, T Flitton, T Rowl

Environmental, social and governance issues (ESG) have become a defining feature in the marketplace to differentiate preferred investments. With the sustainability commitment and reporting landscape anticipated to evolve exponentially, it is now imperative to rapidly develop the approach taken by mineral companies to adequately identify and address ESG risks and opportunities in the reporting of Mineral Resource and Mineral Reserve (MRMR). MRMR cannot be effectively reported as technically and financially assured and realistically executable, if ESG is not integrated into the strategy, business model, input assumptions and process that defines and drives robust MRMR public reporting. Regulatory reporting codes across the globe are presently in various stages of being updated and modified to ensure ESG factors are appropriately covered as a key part of diligent and transparent disclosure. Security exchanges are making it clear that companies must not omit ESG risks from reports to investors. This paper discusses associated challenges for MRMR reporting and suggests avenues for improvement. Key themes include: the importance of procedure rather than prescription and checklists; how ESG criteria impact Modifying Factors and determination of Reasonable Prospects for Economic Extraction (RPEE); the need for financial models to account for material ESG commitments; the uniqueness of each mineral asset; the need for education, upskilling and accreditation of both ESG experts about MRMR reporting and equally Competent Persons in ESG matters; and the need for clear and balanced reports that meet the needs of end users. (RPEE is adopted here for simplicity and consistency, recognising that some reporting codes still include ‘Eventual’ in the term (ie RPEEE). Whilst RPEE and RPEEE are subtly different the intent is to point to the process of assessing ESG factors in determining reasonable prospects.) The principles of transparency, materiality and competence remain paramount when considering the impact of ESG matters on MRMR reporting, and this necessitates an inclusive, cohesive, and integrated approach to assessing ESG issues to ensure the necessary expertise and diligence is applied.

May 24, 2023

By J Q. Shi, M Karakus, Y Liu

Predicting the spatial distribution of rock mass properties in cave mining is a critical challenge. In this study, we introduce a novel machine learning-based model to advance our comprehension of rock behaviour. This model specifically focuses on the spatial distribution of rock mass and mechanical properties, a crucial aspect of our understanding of rock mechanics. Our model is inspired by the recognition that neighbouring information serves as crucial prior knowledge for predicting the spatial distribution of these properties, wherein closer neighbours are likely to exhibit similar characteristics. To effectively capture and model these neighbour relationships, we design a neural network-based model to map the spatial locations within the data set into a new highdimensional space. Within this transformed space, we utilise Euclidean distance to identify N neighbours. Leveraging these neighbours, we introduce a straightforward yet highly effective approach—label propagation—to construct a graph that illustrates neighbour relationships. This graph not only facilitates the prediction of the spatial distribution of rock mass properties but also offers a measure of uncertainty for these predictions. We validate the proposed method using a real rock data set and showcase its efficacy in capturing intricate relationships and distributions within rock properties, enabling precise predictions across diverse spatial scales. Our results underscore the potential of machine learning-based approaches to revolutionise the field of rock mechanics, providing valuable insights applicable to geotechnical engineering, mining, and other sectors where an accurate understanding of rock properties is paramount. This model has direct practical implications, offering a new tool for geotechnical engineers and mining professionals to enhance their understanding and prediction of rock properties, thereby improving safety and efficiency in their operations.

Sep 1, 2024

By N F. Glenn, S Thiruchittampalam, B P. Banerjee, S Raval

The determination of shear strength parameters for the spoil material plays a crucial role in the assessment of a dump’s stability; nevertheless, their evaluation necessitates laborious laboratory experiments. In order to address this issue, Simmons and McManus (2004) formulated a framework that serves as a foundation for categorising spoils according to their distinctive shear strength parameters based on observable and tactile characteristics. This framework, previously identified as the ‘BHP Mitsubishi Alliance Coal (BMAC) Spoil Shear Strength Framework’, is now recognised as the ‘CoalSpoil’ framework. The spoil characterisation provided by the CoalSpoil framework offers benefits but is not without limitations. The examination of these attributes in the field is a time-consuming task that demands expertise. Subjectivity arises in the spoil characterisation when attributes straddle the line between two categories, such as delineating matrix-supported and framework-supported fabric structures. To enhance consistency in the spoil characterisation process, minimising human intervention is crucial to mitigate bias, classification errors, and safety risks. This study seeks to achieve this aim by introducing image-assisted and automated methods for spoil characterisation.

Sep 1, 2024

By S Dunham

For decades we’ve been focusing on reconciliation as a tool to validate mineral resource estimates. And for decades we’ve been misleading ourselves. The concept of reconciliation is simple. Predict, measure, compare and assess the quality of the prediction. This four-step process reflects the ideas of statistical process control and the plan-do-check-act cycle of Shewhart and Deming fame and our intuitive understanding of using system feedback to improve performance. In an ideal world where data is robust and dense this type of feedback loop can be useful. In the mining industry however, there are some fundamental flaws with the conceptual framework. At almost every stage of the process from pre-estimation through to final production the mining system is plagued by material challenges with data and measurement quality and quantity, system delays, and losses from a supposedly closed system. These issues can and do impact on the benefits sought from reconciliation. Instead of providing feedback leading to improved estimation, reconciliation can result in poor decisions, distracting investigations, and exacerbate the noise in an already noisy system. Before we can rely on reconciliation as a management tool, we need to address the multiple challenges present in our everyday practices. Some of the most critical issues are addressed in this paper.

May 24, 2023

By C Zhang, I Canbulat, S Saydam, H Yu, H Chen

Natural rocks are frequently exposed to groundwater and complex geological conditions. Environments with water presence are more susceptible to chemical corrosion, which notably affects rock’s micro properties. Generally, the pH of acid mine drainage in hard rock mines can be low to 5, and the pH of quarrying waste deposits can be below 3. With the expanding scope of mining engineering in aquifers and salty areas, chemical corrosion can also caused by different types and concentrations of anions. The anions can significantly affect rock’s mechanical properties. Therefore, it is critical to emphasise the impact of anion and acid on the mechanical and micro characteristics of rock. This paper commences with an introduction to representative corrosive environments. Then the UCS tests are conducted on granite samples corroded by chloride ions and sulfate ions. Anion has negative effects on the strength of granite. The reason is that certain minerals can react and be dissolved by anions and hydrogen ions, such as Al2O3. Furthermore, the scanning electron microscope (SEM) shows that the roughness of the fracture surface increases with the anion concentration. The effect of acid is notably more pronounced than anion on the micro properties of granite. The initiated fissures and pores also increase with the concentration of SO42- and Cl- ions, which is the micro explanation for the impact of anion on rock strength and stability. Subsequently, the permeability of the granite specimens is tested. The reason that granite performs insensitivity to acid and anion is attributed to its low permeability and high content of inactive oxides, such as quartz. To summarise, anionic and acidic conditions can slightly deteriorate the mechanical and micro properties of granite. While SO42- demonstrates a higher level of corrosiveness on granite than Cl-.

Sep 1, 2024

By K Zhao, H Gong, B Li

Health and safety are the first priority for Australian minerals sector. Australia has a global reputation in the mining industry. However, accidents occur every year. Legislation and regulation are important to prevent the accident from occurring, so do the new technologies. It is sad to witness the collision incident persisting and the long called collision avoidance system (CAS) is still not widely used in underground mines. The main reason is that the existing systems are still not advanced enough. The current CASs utilise GPS, infrared, ultrasonic, RFID, Radar, electromagnetic etc have their limitations and disadvantages. For instance, GPS is widely used in a surface mine, but it cannot be applied in underground mine; Infrared and electromagnetic have the false positive problem.

Sep 1, 2024

By M Bond, R R. Hargreaves, G W. Booth

There are numerous causes of speculative mineral resource and reserve inflation. Traditionally, these are linked to issues of data accuracy or misinterpretation, the use of overly optimistic estimation parameters or assumptions, an absence of independent expert verification, or the simple pressure to increase company value, covert or otherwise. Owing to its subjective nature, classification of resources and reserves remains an opaque process. Of necessity, Competent Persons rely on personal heuristic interpretations, ideally underpinned by appropriate estimation and classification experience across commodity and deposit types. Whereas independent verification of individual resource and reserve statements remains impractical, publicly available data can be interrogated for potential category inflation, particularly when viewed with exploration expenditure statistics included in annual company reports. Abrupt changes in category tonnages and market capitalisation without concomitant expenditure can aid in outlier detection. Consequently, a comparison of common exploration and resource reporting parameters offers a basis for risk assessing classification robustness, over time. In this introductory study, an analysis of globally listed companies was undertaken over a multi-year period, examining base and precious metal projects in both preproduction and operational asset classes. From these, a series of exploratory decision tree trigger points were generated against which target companies were anonymously identified and risk-ranked.

May 24, 2023

By O A. Aladejebi, S Mitra, T Singh, D O’Dea, S, T Honey

Granulation of the iron ore blend and the additives is the foremost step in the agglomeration of iron ore fines to achieve a permeable bed during sintering, which is crucial for sinter productivity. This study investigated the granulation of four types of blends to determine the impact of granulation on bed permeability. The blends were granulated in a rotating drum at various moisture contents and their JPU permeability was measured at each moisture content in a permeability pot (diameter 95 mm and height 500 mm) at various flow rates. Several independent experiments were carried out to investigate the changes in permeability when mixtures of different particle size range (-1 mm and +1 mm) were introduced into a packed bed with a larger particle size range (-6.3 mm to +4.0 mm). The results revealed that the addition of particles in the -1 mm size range had a more pronounced negative impact on permeability compared to particles in the +1 mm size range. This can be attributed to the relatively higher energy losses (mainly inertial) associated with the presence of -1 mm particles in the mixture. The findings were used to quantify the granulation process based on the -1 mm particle size fraction in the granulated mix and their utilisation (denoted by UI-1 mm). For achieving optimal permeability in a specific blend, it was found that a UI-1 mm (utility index of -1 mm particle size) ranging from 0.82 to 0.92 was required. However, exceeding a UI-1 mm value of 0.95 resulted in weaker granules prone to deformation and led to decreased bed permeability. The study also showed that the UI-1 mm was highly dependent on the water addition per kg of -1 mm in dry feed and suggested adding ~80 to 110 mL of water per kg of -1 mm in dry feed to attain the best possible permeability. Additionally, the research proposed a mechanism involving the melting of granules at high temperatures and highlighted the influence of -1 mm particles on bed permeability during the sintering process.

Sep 18, 2023