Mining Productivity

In the past 150 years, the mining industry has achieved remarkable productivity growth. However, since 2000, there have been signs of a slowdown. While some aspects of this decline are cyclical, concerns have arisen that pervious productivity drivers such as high-capacity equipment, are losing their impact. Mining have always faced a unique productivity challenge due to operating in an industry with depleting assets. Productivity growth must first overcome the effects of asset depletion. Depletion includes more than just grade decline in available resources; it also involves higher stripping ratios, increased complexity, ore impurities, and the safe disposal of waste materials (Humphreys, 2020). According to the Australian Bureau of Statistics, mining multifactor productivity experienced a 2.8% decline in 2021-22, marking the second consecutive annual decrease. This decline was primarily attributed to a 1.3% drop in gross value added (GVA) due to factors such as reduced production for certain commodities, adverse weather conditions, COVID-19-related absenteeism, and extensive maintenance activities. Additionally, the report indicates that labour productivity saw a significant decline of 5.1%, the most substantial decrease among market sector industries, resulting from reduced GVA and an increase in total hours worked (Estimates of Industry Multifactor Productivity, 2021-22 Financial Year | Australian Bureau of Statistics, 2022).

Technology Landscape in Mining Productivity

Mine productivity refers to the efficiency and output of mining operations, primarily focusing on the improvement of extraction and processing of mineral deposits. It plays a crucial role in the profitability and sustainability of mining operations. Several factors and strategies influence mine productivity: 

Advanced Technology Adoption: The integration of cutting-edge technology, such as autonomous vehicles, bulk ore sorting, sensor-based sensing, and advanced cutting technology, can enhance productivity by optimising various aspects of mining and processing operations. The deployment of these technologies improves productivity by reducing costs and enhancing resource utilisation.

Efficient Resource Extraction: A more efficient method of mining involves the selective extraction and pre-concentration of ore bodies either at or near the mining face, while minimising waste production. The utilisation of advanced mining techniques, such as in-place mining and the deployment of continuous mechanical cutting equipment, can significantly enhance selective mining practices, ultimately resulting in elevated ore recovery rates.

Optimised Mine Planning: The use of advanced mine planning and design tools can optimise the layout and sequencing of mining activities, minimise waste, improve resource utilisation, and ensure the safety of personnel and equipment. With the ongoing computational advancements and the emergence of high-performance computing systems like quantum computing, mine planners will be able to leverage comprehensive system optimisation to their advantage.

Maintenance and Equipment Reliability: Ensuring the reliability of mining equipment through proactive maintenance and monitoring programs is essential. Equipment breakdowns and unplanned downtime can have detrimental effects on productivity, leading to delays and increased costs. Therefore, implementing rigorous maintenance and monitoring based on the input from digitisation technology is a strategic investment in safeguarding operational continuity and efficiency. 

Environmental Considerations: Environmental regulations and sustainability objectives play a significant role in mine productivity. Responsible mining practices that minimise environmental impact and comply with regulatory requirements are essential for maintaining operational continuity. The integration of mine planning and mine closure considerations can significantly reduce environmental consequences and associated costs. By incorporating these elements into the mining process, operations not only meet their legal obligations but also contribute to the long-term sustainability of both the industry and the environment.

Workforce Skills and Training: A skilled and well-trained workforce is essential for efficient mine operations. Investing in training programs and ensuring that personnel are up to date with the latest mining technologies and safety protocols is crucial.

Energy Efficiency: Energy consumption can account for a substantial portion of mining costs. Employing energy-efficient equipment and practices can reduce operational expenses while improving overall productivity. Additionally, incorporating green energy from renewable sources into the mine's energy portfolio can help reduce costs, align with environmental agreements, and mitigate the risk of energy shortages.

Data-driven decision making: Leveraging data analytics and artificial intelligence (AI) plays a pivotal role in the mining industry, offering the potential for significant improvements in operational efficiency and maintenance practices. By harnessing the power of data analytics and AI, mining operations can identify operational inefficiencies promptly. The real-time data analysis capabilities of AI enable mining professionals to make informed decisions promptly. It provides a dynamic view of ongoing processes, allowing for immediate adjustments to optimise efficiency and resource utilisation.

Stochastic planning and design: External economic factors, such as commodity prices and market demand, have the potential to substantially influence mine productivity. Moreover, the inherent uncertainty associated with the orebody's characteristics can lead to unreliable outcomes. Therefore, it becomes imperative to employ more dynamic valuation methods, such as real options valuation, in conjunction with stochastic orebody modelling and stochastic optimisation techniques to effectively address these uncertainties.

Several roadmaps and strategies have been implemented in Australia with the aim of addressing long-term mine productivity and sustainability. The Mining Industry Growth Centre (METS Ignited) is a government-funded centre in Australia that focuses on the mining equipment, technology, and services (METS) sector. METS Ignited has provided funding for various projects dedicated to enhancing mining technology, automation, and sustainability (METS Ignited - Industry Growth Centre | Mining in Australia, n.d.).

The Commonwealth Scientific and Industrial Research Organisation (CSIRO) has also contributed by developing the Mining Equipment, Technology, and Services Roadmap, which aims to unlock future growth opportunities for Australia (CSIRO, n.d.). This roadmap outlines key opportunities for METS companies, including social and environmental sustainability, data-driven mining decisions, mining automation and robotics, advanced extraction techniques, and exploration in challenging environments.

Additionally, the Queensland government has introduced a 10-year Mining Equipment, Technology, and Services Roadmap to realise the vision of expanding the economic contribution of the state's METS sector and increasing employment within this knowledge-intensive industry.

Challenges and Opportunities in Mining Productivity for the Mining Industry

The mining sector is confronted with a diverse range of challenges that highlight the need for enhancing mine productivity. It is imperative to address these challenges to ensure the industry's long-term viability and competitiveness. These challenges predominantly revolve around several key issues, including the declining ore grade, the deepening of ore deposits, enhancing energy expenses, the urgent for sustainable practices, and shortage of water resources. The extraction of minerals from low-grade and deep ore bodies demands a significant energy input for rock transportation and enrichment. Furthermore, the reduction in mineral head grade has contributed to the proliferation of tailing dams and the accumulation of waste rock dumps, intensifying their negative environmental impact.

To overcome these challenges, the implementation of novel technologies designed to facilitate selective and precise mining and processing has become increasingly important. Notably, there are remarkable opportunities for advancement in this regard:

Rock sensing and characterisation: Sensing technologies are currently in high demand within the mining industry. These technologies include a range of tools, including remote sensing sensors, measurement while drilling (MWD) technology, and advancements in photogrammetry, all of which have the potential for further improvement. The primary objective of such technologies is to enhance the resolution of orebody shape and characterisation. The acquisition of a precise and accurate image of the orebody will result in improving ore recovery rates and reducing waste dilution.

Sensing technologies are continuously evolving, driven by the goal of estimating rock properties and identifying geotechnical structures more accurately. A range of technologies is readily available for deployment at mining sites to enhance our understanding of orebodies and rock specifications. Remote sensing technologies like reflectance spectroscopy, LIDAR (light detection and ranging), and ground penetration radar, for instance, are deployed to generate subsurface images, including void detection and information about rock layers.

Borehole logging technologies, such as acoustic and optical televiewer logging, gamma ray logging, and resistivity technology, are also available, providing valuable data on geo-technical, geo-metallurgical, and structural aspects. Additionally, photogrammetry and image processing technology play a pivotal role in analysing mining faces and creating rock property models.

In addition to these technologies, measurement while drilling technologies are emerging as crucial instruments for detecting rock formation characteristics. These sensors encompass directional sensors, gamma ray sensors, resistivity sensors, and temperature sensors, all of which are utilised to collect and analyse rock information during exploration drilling or blast hole drilling operations.

Despite the advancements in rock sensing technologies, there remains significant room for exploration and improvement. While several technologies are available in the market, enhancing the resolution of sensing remains a priority. Challenges associated with the mining environment, such as the presence of water, dust, or high rock pressure, can limit the effectiveness of sensing technologies. Moreover, the efficient transfer of data through the ground requires further enhancements. Most importantly, integrating sensing data into the decision-making process for operational optimisation represents an ongoing research and development attempt that demands attention.

In-place mining: In-Place mining, which is motivated by the concept of minimal rock movement and processing In-place, promises several advantages. In-Place mining results in a smaller surface footprint, reduced tailings generation, increased automation, and a lower both capital and operating costs. 

In-Place mining defines three methodologies that can be deployed based on the ore body and mining method: In-Line Mining (ILM), In-Mine Recovery (IMR), and In Situ Recovery (ISR). While each method operates independently, there are interconnections between them. All these methods share the common benefits of reducing rock movement, enhancing the quality of extracted materials, and effectively addressing the waste extraction and processing operating costs.

ISR is a well-known, established, and cost-effective method for commodity extraction that doesn't require rock movement. It involves in-situ ore processing; however, its performance depends on factors such as geology, geo-metallurgy, and rock permeability.

In the IMR approach, hard rock stopes are fragmented using advanced fracturing techniques, followed by the recovery of metal content using environmentally friendly leaching solutions.

The ILM concept integrates selective mining and ore upgrading, enabling concentrated material transportation to the processing facility. ILM utilises technologies that can be deployed at or near the mining face to selectively mine and pre-concentrate material, significantly reducing material movement to the surface.

Desktop study of the potential for In-Place Mining techniques to add value to an archetype IOCG deposit

Pre-concentration technology: Pre-concentration involves the process of enriching materials just before they reach their primary concentrations. Various technologies have been proposed and implemented for pre-concentration, including the use of pre-concentrator plants, such as modular processing plants, and ore sorting. Several significant advantages are associated with pre-concentration, which include:

• Reduction in energy and water consumption per tonne of produced metal.

• Expansion of resource potential through cut-off grade reduction, potentially extending the life of a mine.

• Increased overall metal production.

• Lower capital expenditure due to smaller plant size and reduced environmental footprint.

• Decreased need for tailings storage, reducing associated risks.

• An opportunity to enhance the project's net present value (NPV).

Ore sorting includes two major branches of bulk and particle sorting. Bulk ore sorting is particularly suitable for low-grade and medium-grade operations with large tonnage. This method pre-concentrates ore at an exceptionally low operating cost by classifying small blocks of material. Bulk sorting has demonstrated its effectiveness in various base metal operations, and in some instances, it has transformed economically unviable greenfield projects or satellite deposits into feasible ones. Particle sorting is another viable option, especially for operations with low throughput but high-value ore. Particle sorting is an extremely selective pre-concentration method that effectively separates waste while achieving remarkably high recovery rates. This sorting approach has found applications in both base metal and precious metal mining.

Several ore sorting technologies are currently in use. X-ray fluorescence (XRF) sorting is well-established for surface scanning and ore sorting. However, it may be more suited for laboratory settings and less suitable for real-time measurements in bulk ore sorting applications. Prompt Gamma Neutron Activation Analysis (PGNAA) and Passive/Fast Thermal Neutron Analysis (PFTNA) are techniques capable of penetrating all materials on a conveyor belt, even at high speeds, providing more precise measurements in bulk ore sorting scenarios.

There have been a few reported attempts to integrate pre-concentration processes into underground mining operations. One such example is the deployment of the Gekko Python pre-concentration line at Nunavut gold mine, Canada (Hope Bay Gold Mine, 2020). Another instance involves the ore sorting trial at Elizabeth Creek Copper Project, South Australia. The trial's results anticipate an upgrade in mineral processing head grade from 1.87% CuEq to 2.15%, with metal recoveries remaining as high as 97.1% despite a 15% rejection rate (Coda Minerals Ltd, 2023). Agnew in Western Australia is yet another underground mine currently evaluating opportunities for ore sorting technology, following the initial trial in 2018 (Gold Fields Mineral Resources and Mineral Reserves Supplement 2018 | Agnew Gold Mine, n.d.). The benefits of incorporating pre-concentration into underground mining extend beyond significant reductions in surface processing and flotation costs. They also include more efficient waste management, reducing handling and transportation costs. However, this integration is complex and necessitates a thorough investigation and analysis before the installation of a pre-concentration system. This evaluation should consider various constraints, including critical characteristics like mineralogy, rock mass analysis, and equipment, as well as installation mechanisms such as appropriate technology, hoisting, and backfilling. In the case of underground methods with backfilling requirements, like cut and fill mining, the geotechnical strength of rejected materials from pre-concentration systems must meet stability criteria while also minimising associated risks.

Despite substantial progress in pre-concentration technologies, limitations still exist. The capacity of ore sorting, and pre-concentration remains a challenge, particularly as the mining industry relies on economies of scale for large-scale production. Furthermore, existing technologies are primarily suited for specific types of ore bodies, and as ore body characteristics change, their applicability may diminish. Consequently, ongoing research and development efforts are crucial to advancing and maturing pre-concentration technologies to address these challenges effectively.

Mechanical Cutting: Mechanical cutting uses a range of equipment, including road headers, continuous miners, and tunnel boring machines, each utilising distinct cutting tools such as picks, discs, and drum cutters. These machines excel at making precise cuts, particularly in coal seams or softer materials, thereby mitigating the risk of overbreak or damage to adjacent walls. Unlike traditional blasting methods, mechanical cutting inherently enhances safety by minimising exposure to hazardous conditions. Furthermore, it aligns effectively with sustainability in mining, reducing environmental impacts by generating less vibration, dust, and noise pollution.

The continuous nature of mechanical cutting fosters a more efficient mining system, eliminating the need for extended blasting time window. Notably, one of its key advantages lies in its compatibility with autonomous mining, facilitating the realisation of a zero-entry mine environment. In contrast, traditional blasting, along with its preparatory and aftermath activities, poses significant challenges to achieving this goal.

 Continuous rock cutting technology is continually advancing, with the development of undercutting-disc systems tailored for hard rock applications progressing towards the commercial prototype stage. Mining3 pioneered the Oscillating Disc Cutter (ODC), forming the foundation of this continuous cutting technology. This patented disc technology operates with lower forces than conventional disc cutting methods, enabling the cutting of very hard rock using compact, low-input power, and lightweight equipment. Subsequently, the technology was licensed to Joy Global (now Komatsu), which collaborated with Mining3 to further refine and market it as DynaCut™.

Despite the significant advantages offered by mechanical cutting and its widespread adoption in coal and soft rock mining, its utilisation in hard rock mining remains limited. Primarily, this limitation arises from the lower production rates achievable in harder rock conditions. Additionally, the relatively higher capital and operating costs associated with mechanical cutting, compared to traditional drilling and blasting, present barriers to its broader development. Nevertheless, a significant opportunity exists to further advance mechanical technology and integrate it with the concept of in-line mining, harnessing the benefits of precision mining in challenging hard rock environments.

Advanced Mine Design and planning:  The utilisation of advanced mine planning and design tools plays a pivotal role in optimising the arrangement and sequence of mining operations. While diverse solutions are available in the market, there are evident gaps that hinder the full realisation of the potential offered by these tools, indicating areas that warrant further exploration and development.

Since the beginning of computerised mine design and planning, numerous decision-making challenges have been addressed, making solutions accessible to the industry. However, due to computational limitations, optimisation has often been structured in a stepwise manner, resulting in suboptimal decisions. With the advancement in computational capabilities, an opportunity emerges to integrate the various stages of mine planning, ranging from data collection to operational scheduling.

Moreover, the introduction of new technology in mining engineering necessitates a different approach to mine design and planning. With autonomous equipment in operation, the conventional practice of dispatching machinery based on predetermined and driver-oriented schedules needs to transition towards a more adaptable, fuzzy-logic-based decision-making process driven by autonomous robots.

Mine planning heavily relies on the estimation of rock properties, typically referred to as the block model. The advent of new data collection technologies allows for the creation of a more precise block model to serve as input for the planning process. To update all planning and scheduling activities, a rapid reconciliation method becomes vital. The conventional discrete, multi-step process involving data collection, block model updates, short-term planning, and fleet scheduling often leads to decision-making delays. Hence, there is a growing need for an integrated planning and scheduling framework directly linked to the data collection process, capable of responding to real-time updates and changes.

Mining3 has a robust and extensive track record of developing technologies to address the challenges outlined above and to enhance mine productivity. Our organisation has been at the forefront of innovation, introducing the revolutionary concept of in-place mining and subsequently developing modelling and planning tools to assess these opportunities thoroughly. In the past seven years, Mining3 has successfully completed 19 projects related to increasing mine productivity, with a total value of approximately five million dollars. Mining3's strategy for achieving selective mining centres on the integration of cutting-edge rock sensing technology, advanced mechanical cutting methodologies, and pre-concentration technologies. Furthermore, we have actively employed complex simulation practices as part of our efforts to evaluate scenarios, particularly considering the inherent uncertainties that exist in mining operations.

Through dedicated collaborative research and development initiatives, our ultimate objective is to fully harness the potential of emerging technologies, thereby delivering innovative solutions that establish new industry benchmarks.