Journal of the Southern African Institute of Mining and Metallurgy
Journal of the Southern African Institute of Mining and Metallurgy aims to disseminate technical and topical information related to mining & metallurgy to the members of the Southern African Institute of Mining and Metallurgy to ensure that their information needs for technological and scientific knowledge of the minerals and metals sectors in South Africa are met. The SAIMM publishes technical and associated legal and economic information on all aspects of the minerals and metals industry.
The Southern African Institute of Mining and Metallurgy
THE INSTITUTE, AS A BODY, IS NOT RESPONSIBLE FOR THE STATEMENTS AND OPINIONS ADVANCED IN ANY OF ITS PUBLICATIONS. Copyright© 1978 by The Southern African Institute of Mining and Metallurgy. All rights reserved. Multiple copying of the contents of this publication or parts thereof without permission is in breach of copyright, but permission is hereby given for the copying of titles and abstracts of papers and names of authors. Permission to copy illustrations and short extracts from the text of individual contributions is usually given upon written application to the Institute, provided that the source (and where appropriate, the copyright) is acknowledged. Apart from any fair dealing for the purposes of review or criticism under The Copyright Act no. 98, 1978, Section 12, of the Republic of South Africa, a single copy of an article may be supplied by a library for the purposes of research or private study. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means without the prior permission of the publishers. Multiple copying of the contents of the publication without permission is always illegal. U.S. Copyright Law applicable to users In the U.S.A. The appearance of the statement of copyright at the bottom of the first page of an article appearing in this journal indicates that the copyright holder consents to the making of copies of the article for personal or internal use. This consent is given on condition that the copier pays the stated fee for each copy of a paper beyond that permitted by Section 107 or 108 of the U.S. Copyright Law. The fee is to be paid through the Copyright Clearance Center, Inc., Operations Center, P.O. Box 765, Schenectady, New York 12301, U.S.A. This consent does not extend to other kinds of copying, such as copying for general distribution, for advertising or promotional purposes, for creating new collective works, or for resale.
A review of current practices of Survey control in sinking shafts in Southern African operations
Shaft sinking practices in Southern Africa are well established. Contractors and mining houses have refined the standards and procedures used in the spatial control of shaft sinking, construction and infrastructure development over the past decades. These procedures are not always documented well, and as the number of sinking operations decline, there is a significant risk that this hard won knowledge may be lost to new generations. This paper summarises current shaft sinking survey practice, and although it does not claim to be a complete summary of the science, it reflects current practices and future developments.
Copyright (c) 2026 Steven Michael Rupprecht, Hennie Grobler, Errico Vascotto https://creativecommons.org/licenses/by/4.0
Comparison of CRIRSCO Template-based mineral reporting codes with implications for mine planning in mineral development projects
From 2022 to 2040, the global demand for mineral commodities is projected to increase by four-fold to six-fold, largely due to traditional drivers such as population growth and urbanisation compounded by the adoption of decarbonisation technologies that are more mineral intensive than fossil fuel technologies. To meet this projected demand, companies operating in the minerals industry should accelerate the development of mineral projects. Since most of the companies generally operate in multiple geographical, regulatory or legislative jurisdictions, it is critical that the information on Mineral Resources and Mineral Reserves they report in the public domain should be comparable and consistent across different jurisdictions. The Committee for Mineral Reserves International Reporting Standards (CRIRSCO) fosters alignment of national and/or regional mineral reporting codes through an internationally accepted template that creates a common technical understanding of definitions, classification, estimation processes and the Public Reporting of Exploration Results, Mineral Resources, and Mineral Reserves. CRIRSCO Template-based codes guide reporting at respective national and/or regional levels. Since mine planning is critical in converting Mineral Resources to Mineral Reserves, a shared technical understanding should aid comparability of mine planning results. However, differences persist in the way mine planning results are reported. Unlike most previous studies, which primarily focused on comparing mineral reporting codes, this paper updates and extends such comparisons by exploring how similarities and/or differences in reporting should influence the mine planning process. It also recommends some principal and process changes to assist mine planning professionals in improving consistency and comparability in reporting mine planning results.
Copyright (c) 2026 Mark Burnett, Dr Clinton Birch, Professor Cuthbert Musingwini, Dr Godknows Njowa https://creativecommons.org/licenses/by/4.0
Attainable region analysis for batch/continuous reductive column leaching of oxidized cobalt-bearing ore
This study investigates the solubilization of cobalt using sulfur dioxide (SO₂) and sulfuric acid (H₂SO₄) in a batch reactor system, employing attainable region (AR) analysis to optimize yield and minimize SO₂ loss. Experimental data, validated through an independent set, enabled the modeling of yield versus SO₂ loss, highlighting operational boundaries for enhanced reactor design. The simulations incorporated kinetic parameters for cobalt (k_Co = 0.025 min⁻¹) and SO₂ (k_SO₂ = 0.01 min⁻¹), with the AR curves plotted to guide the development of efficient processing strategies. The analysis demonstrated that different reactor configurations—including plug flow reactors (PFRs), continuous stirred-tank reactors (CSTRs), and hybrid PFR–CSTR networks—can be evaluated within the AR framework to identify optimal designs. The hybrid configurations offered potential pathways to approach the upper boundary of the AR, where both high yield and low SO₂ loss are achievable. The methodology also addressed challenges such as reactant depletion and recirculation effects. This AR-based approach provides a flexible decision-support tool for guiding future reactor scale-up and continuous operation. Further work is needed to validate these insights at pilot and industrial scales, including integration with economic assessments and process control models.
Copyright (c) 2026 Meschac-Bill Kime https://creativecommons.org/licenses/by/4.0
3678 Investigation of the effect of mechanical, drillability, abrasiveness and excavability properties of Zonguldak Basin coal surrounding rocks on grindability
In this study, the grindability of 7 different coal environment rocks (sandstone, siltstone) from the Zonguldak Basin, Uzulmez Region was investigated. For this, Hardgrove Grindability Index (HGI) and Bond Work Index (BWI) tests were conducted. While determining the relationships between grindability and other parameters, the results obtained from the Hardgrove Grindability Index (HGI) test were used. The energy values found in the Bond Work Index (BWI) test were used to evaluate the excavability of the rocks. Additionally, tests for strength, hardness, drillability, and abrasiveness were conducted to observe the impact of other parameters on grindability. Considering the results obtained from the experiments, significant relationships were found between the grindability of the rocks and other parameters.
Copyright (c) 2026 Çağrı Aldı, Olgay Yaralı https://creativecommons.org/licenses/by/4.0
3747 systematic Review of Quadrotor-Track Hybrid Subsea Robotic Systems for Offshore Mineral mining in Industry 4.0
The Fourth Industrial Revolution (4IR) has driven significant advancements in autonomous robotic systems, particularly in subsea exploration and offshore mineral dredging. This review examines the latest developments in electrically powered quadrotor-track subsea robotic crawlers, highlighting their potential to enhance efficiency, mobility, and adaptability in challenging underwater environments. The integration of advanced automation, artificial intelligence, and real-time control systems has paved the way for more effective robotic solutions in offshore mining. This study explores the dynamic performance of hydraulic crawlers to quadrotor-track robotic dredgers, focusing on their propulsion, navigation, and stability under high hydrodynamic conditions. By leveraging state-of-the-art technologies such as lithium-ion battery power systems, intelligent microprocessors, and sensor-based control mechanisms, these robotic crawlers offer a promising alternative to conventional subsea excavation methods. Furthermore, the review analyzes recent experimental and simulation-based studies that assess the feasibility and performance of these systems in real-world applications. The findings of this review provide valuable insights into the role of 4IR in transforming subsea robotics for offshore mineral dredging. By addressing existing limitations and identifying key technological advancements, this study contributes to the ongoing development of next-generation robotic systems capable of operating efficiently in extreme underwater conditions.
Future Water Developments for the Mining Industry
Copyright (c) 2026 Mike Oluwaseun Ojumu, Atanda Kamoru Raji, Efe Francis Orumwense https://creativecommons.org/licenses/by/4.0
3805 Determining the impact of haulage optimisation on open pit mining economic and environmental challenges: A case study
This study proposes a new approach to reduce the environmental impact during surface mining by improving environmental factors through the incorporation of carbon footprint into strategic mine planning. Two key variables were analysed by contrasting and comparing the baseline and optimised models generated. These variables include Net Present Value (NPV), which helps determine the financial feasibility of the mining models and their carbon emissions. The variables were analysed by using linear regression, Spearman’s correlation, a P-value hypothesis and an exponential decay tests. Results show that at Mine A’s projected NPV was 62% higher than when running a baseline model. Furthermore, the NPV from the baseline model portrayed a high rate of decay at 0.667 versus 0.118 from the optimised model. This indicates the baseline model’s sensitivity to long-term project timelines and fluctuating markets. The optimised method presents an opportunity to manage emissions during the high operational cost phases. It is represented by a 31% improvement in carbon emissions during the periods of high operational costs, whilst maintaining a positive NPV when compared with the baseline model. The optimised model presents a better chance of achieving financial feasibility and balancing environmental impact, thereby ensuring that Mine A can align with the environmental aspect of ESG through lowering the carbon footprint resulting from its hauling operations. Keywords: Strategic mine planning; NPV; Carbon foot print; Environment; Haulage optimisation; ESG
Copyright (c) 2026 Bekir Genc, Priscilla https://creativecommons.org/licenses/by/4.0
RISK-BASED SLOPE DESIGN: INSIGHTS FROM THE THABAZIMBI FAILURE
Certain degrees of safety, economic and financial risk are implicit in any mining operation. At Thabazimbi Mine, slope stability was one of the major sources of risk, largely due to data uncertainties. Consequently, a risk-based approach in slope design was followed. On the 6th of June 2015, a slope failure occurred in Thabazimbi Mine’s Kumba Pit, involving approximately 65 million tonnes of rock failing into the pit and the valley below. Although the failed mass moved rapidly and resulted in a run-out distance of approximately 900m, controls had been put in place to successfully evacuate all personnel. Risk assessment during the onset of failure supported the decision to not compromise the safety of personnel in any way, leading to unavoidable equipment loss. This contribution presents the failure as a case study in the context of a risk-based approach to slope design as well as the importance of implementing geotechnical controls to effectively manage slope instability risk. Furthermore, a comprehensive back-analysis was performed, on a fully-constrained 3D model, utilising 3DEC, to gain insights into the failure mechanism. In conclusion, lessons from the Thabazimbi slope failure are valuable as they demonstrate the importance of following a risk-based approach in slope design to effectively manage safety and financial risk in open pit mines.
Copyright (c) 2026 Marnus Bester, Thandile Dlokweni, Ian Basson, Corné Koegelenberg https://creativecommons.org/licenses/by/4.0
3629 Development of Mining Industry in Tanzania: A review
Tanzania is a country with a variety of mineral deposits, including metallic minerals, gemstones, mineral fuels, industrial minerals, and critical minerals. This study provides an overview of mining legal framework, mineral occurrence and production, challenges and government initiatives. The aim is to demonstrate the development of mining sector in Tanzania and explore the potential for further mining investment in the country. The mineral production data showed generally increasing trends over the years; for example, gold production increased from 42 tonnes in 2018/2019 to around 50 tonnes in 2023/2024. Despite the growth, the mining sector encounters several challenges, including: lack of detailed geological information of mineral deposits, inadequate infrastructures in some remote mining sites, the existence of informal artisanal miners, and mineral smuggling. The Tanzanian government has made several initiatives to address these challenges including; carrying out the high-resolution airborne geophysical survey to increase geological information in some areas; formalization of more artisanal and small-scale miners; establishment of mineral markets to combat mineral smuggling; and encouragement of mineral value addition within the country
Copyright (c) 2026 Dr. Baker Francis Giyani, Dr. Abubakary Salama https://creativecommons.org/licenses/by/4.0
3769 Investigating the Impact of Mineral Royalty Fiscal Regime Changes on the Viability of Mining the Zambian Copper Orebodies
Zambia’s mining industry has struggled with mineral royalty fluctuations since 2008. Unlike many analyses not supported by empirical evidence, this study investigates the impact of mineral royalty on the net present value (NPV) and cut-off grade (COG) of Zambian copper deposits. The study employs the cut-off grade and mineral royalty model relationship (COGMRMR) for the assessment. The results showed that the changes in the NPV were 10.39%, –3.40%, 6.13%, 9.69%, 6.13% and 14.92% for Barrick Lumwana, FQM Trident, Kansanshi, Nkana – Mopani Copper Mines (MCM) and Mufulira – MCM copper orebodies, respectively. The positive percentage change in NPV indicated that the rest of the investors experienced losses. On the other hand, the negative percentage change revealed that only FQM Trident Limited gained from the mineral royalty policy changes that were administered by the government. The findings further showed that the net extent of the impact of mineral royalty fiscal regime policy changes on the COG for Barrick Lumwana, FQM Trident, Kansanshi, MCM’s Nkana, and MCM’s Mufulira copper orebodies was 0.42%, 1.20%, 0.42%, –0.24%, –0.38% and –0. 25%, respectively. The positive percentage change in COG revealed a gain to the investors or a corresponding loss to the citizens. Conversely, the negative percentage change in COG signifies a loss to the investor or a gain to the government. Overall, the projects remained afloat. The study underscores the need to fairly share the economic value of mineral assets between investors and the government, making an optimal mineral royalty framework essential to benefit stakeholders.
Copyright (c) 2026 Mwiya Winnyfred Songolo, Edward Chisakulo, Emmanuel Knox Chanda https://creativecommons.org/licenses/by/4.0
3768 Preparation, characterization, and application of spent tyre-derived activated carbon chars for total organic carbon removal from wastewater
The increasing accumulation of scrap tyres, which pose significant fire hazards, and the high-cost disposal of pyrolytic spent tyre-derived char (PTDC) generated during pyrolysis present serious environmental and health concerns. This study investigates the thermal processing of spent tyre crumb rubber (TC) and its PTDC to produce spent tyre-derived activated carbon chars (STACCs) with enhanced physicochemical properties for total organic carbon (TOC) removal from malodorous starch wastewater (SWW), via both physical and chemical activation methods. Samples were characterised using various analyses. Notably, TC2 (TC activated at 850 °C) and TCA2 (TC leached with aqua-regia (TCA) and activated 850 °C exhibited rough surface morphologies, with surface areas of 146 m²/g and 300 m²/g, and pore volumes of 0.8 m³/g and 0.5 m³/g, respectively—values approaching those of other commercial activated carbon (AC). These enhanced surface area and pore structure were attributed to the volatilisation of organic and inorganic species, as well as, the rupture and agglomeration of spherical amorphous particles formed during activation. TC2 and TCA2 achieved TOC removal efficiencies of 56–63% from SWW, compared to 80% by AC. These findings suggest that spent tyres are a promising feedstock for producing STACCs suitable for the adsorption of organic matter from industrial wastewater.
Copyright (c) 2026 Mafunisa Richard Mulaudzi https://creativecommons.org/licenses/by/4.0
TESTING SAMPLE REPRESENTIVITY USING PARTICLE SIZE DISTRIBUTION
Particle size distribution (PSD) analysis is important to many industries for assessing product quality, process efficiency, and compliance with contractual standards, while ensuring sample accuracy and representativeness. Inaccurate PSD results, arising from fines as a result of excessive handling can lead to penalties and buyer-seller disputes. A non-representative PSD means samples will not be representative of the chemical components either. Sampling blast-hole cuttings poses challenges due to large material volumes, segregation, and uneven settling of particles in dense gold bearing ores. Commonly used sampling methods such as spear or sectoral sampling may lack representativeness. PSD analysis is crucial for evaluating sampling methods by comparing test sample representativeness against a reference standard derived from multiple PSD analyses. Acceptable samples must fall within the 97.5% confidence intervals of the standard; deviations. Analyses lying outside these boundaries indicate a strong likelihood of segregation errors. A case study demonstrates this approach by using a 6.005 kg benchmark sample to assess two additional samples (1 kg and 5 kg), highlighting PSD’s role in detecting sampling errors and refining protocols. An example of three test samples collected from RC drill cuttings compared to a standard reference sample is presented to illustrate a QAQC procedure for RC drilling. Key words: particle size distribution, mass fraction, sample representivity, relative difference, RC drilling
Copyright (c) 2026 Richard Charles Anson Minnitt; Prof Minkkinen https://creativecommons.org/licenses/by/4.0
IMPROVING GRADE ESTIMATION USING MACHINE LEARNING
This study investigates the use of machine learning (ML) algorithms as alternatives to Ordinary Kriging (OK) for grade estimation in a platinum group elements (PGE) deposit. OK, while widely used, relies on variogram modeling and spatial assumptions that may limit its performance in complex geological settings. The research evaluated the performance of ML algorithms—Random Forest (RF), k Nearest Neighbours (kNN), Support Vector Regression (SVR), Decision Trees (DT), and Linear Regression (LR)—through both point and block estimation. The models were compared using validation metrics such as R2, Root Mean Square Error (RMSE), and Mean Absolute Error (MAE), as well as swath plot analyses to assess spatial prediction accuracy. RF and kNN achieved the highest R2 values (0.85 and 0.83, respectively), indicating superior prediction accuracy over OK (R2: 0.76). In block estimation, RF and NN also produced the lowest RMSE values, demonstrating robust generalisation across larger spatial extents. By contrast, LR and SVR underperformed due to their sensitivity to linear assumptions and hyperparameter tuning. These findings show that ML algorithms, particularly RF and NN, offer significant advantages over OK in capturing non-linear relationships and local grade variations, paving the way for more accurate and flexible mineral resource estimation.
Copyright (c) 2026 Richard Charles Anson Minnitt, Aniekan https://creativecommons.org/licenses/by/4.0
Enhancing Performance Metrics of an Electrical-Powered Subsea Robotic Dredging Crawler Across Varied Inclination Angles
This research paper introduces a novel passive method for ocean mining using an electric-powered robotic subsea dredging crawler (EPRSDC) designed to operate in various subsea conditions, including unstructured and rough terrain. The EPRSDC is equipped with two driving tracks and features a complex assembly of tank tread chain link, tank tread idler wheels, tank tread sprockets, bronze bushings, motor hub, motor mount, and a 12-volt DC motor. To evaluate the performance of the EPRSDC, it was compared with existing ocean hydraulic exploration crawlers, such as MK3 ROST, in terms of drive performance on an inclined ramp with five angles of inclination (00, 150, 200, 250, 300). The experiment aimed to determine the maximum velocity, torque, and efficiency of the crawler at different angles of inclination. The collected data were analyzed and plotted using Python, and the effect of the EPRSDC's weight on its driving performance was also considered. The results of this study demonstrate a quadratic relationship between driving performance and inclination angle, which can be used to optimize the EPRSDC's performance for future ocean mining robot drive applications.
Copyright (c) 2026 Mike Oluwaseun Ojumu, Raji Atanda Kamoru, Efe Francis Orumwense https://creativecommons.org/licenses/by/4.0
Slope Stability Evaluation of Gneiss Rock Slopes Using SMR and QSlope
One of the biggest problems in open pit mining is slope stability. In order to eliminate stability problems such as geology, climate and production activities should be known, and slope geometries should be selected properly to eliminate those. In this research, the slope stability of rock slopes in a mine opened in gneiss geological unit has been studied. Production activities were stopped in 2019 due to the slope movements in the eastern part of the quarry. In order to continue the production safely, field works have been carried out primarily. Discontinuity measurements were taken at the bench slopes and slope geometries that could remain stable according to geological and environmental conditions were determined by performing kinematic analyzes and numerical analyzes. Engineering geological studies such as scanline measurements in steps and investigation of potential failure mechanisms by kinematic analysis technique were carried out. SMR and Qslope, rock mass classification systems were used to evaluate slope stability. Based on these classification systems potential unstable rock slopes were determined and thematic maps were created using geographic information systems (GIS). The most suitable slope geometries are suggested for these slopes. In addition, the improvement methods suggested by the rock mass classification systems were proposed for these slopes.
Copyright (c) 2026 ENES KALHAN, Cem https://creativecommons.org/licenses/by/4.0
3561 Effects of acid and reductants on iron salts’ leaching of the copper-cobalt oxide ore
Although the traditional Cu-Co oxide ore leaching method (acid-reductive) effectively extracts Cu and Co from Cu-Co oxide ore, hydrometallurgical improvements are still being researched. One of the alternative leaching methods the authors recently studied used FeSO4·7H2O and Fe2(SO4)3 as lixiviants. The present study investigated the effects of H2SO4 and Na2S2O5 addition on Zebesha Cu-Co oxide ore leaching using the above-mentioned lixiviants, aimed to improve leaching recoveries. The ore (<150 µm) was leached at ambient temperature for 2 hours and the X-ray fluorescence technique was used for analysis. Co, Mn and Ni leaching recoveries increased with the increase in Na2S2O5, the highest being about 80% Co at 150 kg/t Na2S2O5 in FeSO4·7H2O, but Cu recovery remained below 5% Cu. On the contrary, using Fe2(SO4)3, about 88% Cu recovery was highest at 50 kg/t Na2S2O5, then slightly decreased to 79% Cu at 150 kg/t Na2S2O5. H2SO4 increased leaching recoveries for both lixiviants. About 60 kg/t H2SO4 increased Cu recovery to 92% in Fe2(SO4)3, while Co, Ni and Mn recoveries remained below 40%. Nevertheless, in FeSO4·7H2O, cobalt leaching recovery was highest, and increased from 40% to 84% Co. Na2S2O5 was best in FeSO4·7H2O for cobalt extraction although manganese and nickel were co-extracted, whereas H2SO4 was best in Fe2(SO4)3 for the extraction of copper.
Copyright (c) 2026 Foibe DL Uahengo, Dr Yotamu Hara, Dr Olga Bazhko https://creativecommons.org/licenses/by/4.0
Development of a Filtered Inverse Velocity Method Analyzer: A Comparative Study of Smoothing Filters in Surface Mines for optimization of slope failure predictions
The Inverse Velocity Method (IVM) has proven to be an effective approach for predicting slope failures in surface mines by analyzing displacement monitoring data. However, the accuracy of IVM predictions is significantly affected by instrumental noise and natural environmental variations, which influence the identification of different deformation stages. To enhance predictive accuracy, this study applies and evaluates three filtering techniques to velocity time series data: Exponential Smoothing Filter (ESF), Short-Term Smoothing Filter (SSF), Long-Term Smoothing Filter (LSF) and also compares it to raw data (no filtering). A refined prediction framework (Filtered Inverse Velocity Method Analyzer) is proposed to improve slope failure forecasting in surface mining operations. The results demonstrate that filter selection plays a crucial role in optimizing failure time predictions, offering valuable insights for geotechnical monitoring and early warning systems in surface mines.
Copyright (c) 2026 Mohd Maneeb Masood https://creativecommons.org/licenses/by/4.0
3738 Challenges in the use of verbal probability expressions in communicating geomechanical risk
Mining companies employ a multitude of risk management tools. The effectiveness of these tools for decision making and communicating risk has not been addressed. This paper investigates the use of verbal probabilistic expressions in communicating geomechanical risk. Analysing survey data obtained from a group of mining geomechanics professionals it identifies limitations of common probabilistic expressions. The paper concludes by making specific recommendations to avoid the use of certain expressions that may result in increased uncertainty thus compromising the use of risk management tools.
Copyright (c) 2026 John Hadjigeorgiou, Johan Wesseloo https://creativecommons.org/licenses/by/4.0
Calibratable Rock Mass Shear Strength for Open Pit Slopes
Open pit slope stability analyses for large scale instabilities are often carried out using Limit Equilibrium, Finite Element or Finite Difference computer programs. All of these require empirical estimates of rock mass shear strength when calibrated values are not available, which, is a common occurrence. A common method of estimating rock mass shear strength is the Hoek-Brown failure criteria, however, this method often over or underestimates rock mass shear strength when used in Limit Equilibrium or Elastic Linearly Plastic slope stability analyses, resulting in published alternative estimates for the coefficients of the Hoek-Brown failure criteria. This paper investigates the differences between Limit Equilibrium and Elastic Linearly Plastic slope stability analysis based on the Hoek-Brown failure criteria. The investigation consisted of a comparison of 3840 RS2 Finite Element analysis models completed with strain softening, and 216 Slide2 Limit Equilibrium models. The models were used to evaluate a methodology to determine equivalent Limit Equilibrium and Elastic Linearly Plastic shear strength parameters that provide the same stable slope angles and instability back break distances as the more representative Strain Softening stress analysis methods This paper presents the methodology, and compiles the results into design charts and equations for equivalent Limit Equilibrium Mohr-Coulomb shear strength parameters, that simplifies calibration against actual case studies. The results compare well with older empirical shear strength estimates, however, a detailed calibration of the results against case studies will need to be carried out.
Copyright (c) 2026 Julian Venter, Callen Banff, E.C.F. Hamman https://creativecommons.org/licenses/by/4.0
3723 Comparative Legal Solution for Rehabilitating Legacy Mines through Financial Provision in South Africa and Western Australia
One understudied area of environmental law is the socio-ecological impact of ownerless mines, which is particularly pronounced in resource-dependent regions like South Africa and Western Australia, creating significant rehabilitation challenges. This article hypothesises that financial provision could be a valuable approach to rehabilitating legacy mines. Using a qualitative, comparative methodology, we analyse the financial provisions for mine rehabilitation in South Africa and Western Australia, focusing on statutory provisions, funding mechanisms, and rehabilitation outcomes. Key themes, such as context, measures, and outcomes, are explored to assess the effectiveness of each financial model. Purposive sampling is used to select case studies from both regions, and thematic analysis is applied to interpret the data. The analysis highlights the financial rehabilitation measures in both regions, providing a structured framework for ownerless mine rehabilitation. South Africa's approach, guided by the Mineral and Petroleum Resources Development Act (MPRDA) of 2002, depends on state budget allocations, leading to funding inconsistencies and slow rehabilitation progress. In contrast, Western Australia’s Mine Rehabilitation Fund Act (MRFA) of 2012 uses a levy-based system, ensuring continuous financial support for mine rehabilitation. South Africa's state-dependent model has led to delays in rehabilitating derelict and ownerless mines (DOMs), while Western Australia's funding model has facilitated steady progress. We suggest that South Africa adopt a levy-based financial mechanism, strengthen legislative enforcement, improve financial oversight, and integrate proactive mine closure strategies to accelerate rehabilitation, reduce environmental hazards, and promote sustainable development in mining-affected communities. Key words: South Africa, Western Australia; legacy mine, mine rehabilitation, financial provision
Copyright (c) 2026 Fredua Agyemang, Dr https://creativecommons.org/licenses/by/4.0
1619 FATIGUE PERFORMANCE IMPROVEMENT USING LASER SHOCK PEENING FOR THREE MATERIALS
Fatigue life improvement can be achieved through surface treatments such as laser shock peening (LSP). LSP introduces residual stresses, penetrating 1 mm into the surface of the material. LSP resulted in a fatigue life increase of 5.4 times for AA7075-T6, when the surface roughness was 0.2 micrometres. The effect of LSP on fatigue performance for Ti-6Al-4V and AISI316 shows an improvement in fatigue life by 5 times and 1.7 times respectively. Fractography and crack path analysis were used to investigate the effect of LSP on the fracture. The results show that the efficacy of the LSP process varies between different materials.
Copyright (c) 2025 Sarah George https://creativecommons.org/licenses/by/4.0
3685 On the evaluation of destress blasting for deep level hard rock mining
Deep level hard rock mining faces significant challenges due to elevated in-situ stresses, resulting in hazardous rockbursts and seismic events. Destress blasting is a crucial preconditioning technique that mitigates these risks by redistributing stresses and reducing stored strain energy ahead of mining excavations. This study systematically evaluates the effectiveness of destress blasting by consolidating research on numerical modelling, field-based monitoring, and rockburst prediction criteria. It critically examines numerical simulation techniques, including static and dynamic modelling, to optimise blast parameters such as explosive energy distribution, borehole spacing, and initiation sequences. It also assesses geophysical monitoring tools like Ground Penetrating Radar (GPR) and borehole periscopes for evaluating blast-induced fracture networks, alongside seismic analysis methods for tracking microseismic activity before and after blasting. Key rockburst prediction indices – Strain Energy Storage Coefficient (F), Brittle Shear Ratio (BSR), and Burst Potential Index (BPI) – are explored for their applicability in quantifying stress relief efficiency. The study identifies gaps in existing research, including the need for improved predictive models, enhanced integration of monitoring data, and site-specific adaptations for different geological conditions. Its structured evaluation framework combines empirical assessments with theoretical and computational approaches, providing a holistic understanding of destress blasting performance. The study advances destress blasting strategies, improves safety protocols, and optimises stress management in deep underground mines. Future research should refine numerical simulations with real-time seismic data, integrate machine learning for predictive analysis, and develop standardised performance assessment criteria to enhance destress blasting effectiveness.
Copyright (c) 2025 Bekir Genc, Mr Tawanda Zvarivadza, Professor Onifade, Manoj Khandelwal, Mr Changping Yi, Professor Dineva https://creativecommons.org/licenses/by/4.0
3686 Reflections on destress blasting for deep level hard rock mining: key considerations for successful application of the techniques
Deep hard rock mines worldwide increasingly face rockbursts as mining depths increase. The accumulation of stress at depth results in violent and sudden energy release, causing rockmass damage. Rockbursts present numerous challenges, including fatalities, injuries, damage to expensive mining machinery, loss of production areas, increased material handling and excavation rehabilitation costs, and broader social and economic impacts. This paper focuses on destress blasting as one of the strategies for managing rockbursts. Practical experience with destress blasting in Swedish deep hard rock mines is limited, necessitating a review of global experiences to inform best practices in Sweden. Previous studies have shown that destress blasting stabilises mining excavations by redistributing peak stress away from mining zones into the surrounding rockmass, primarily by extending fractures. Key factors for an optimal destress blasting design include stress regime, rockmass properties, blast borehole dimensions and spacing, explosive properties, initiation sequence, and mining sequence. Given the geological and geotechnical variability across and within mines, it is impractical and costly to test numerous destress blasting design permutations in actual mining conditions. Numerical simulations play a crucial role in optimising designs by evaluating stress, energy, and stiffness variations to determine the most effective parameters before field implementation. This study also presents different approaches for evaluating the effectiveness of destress blasting and highlights current research limitations, recommending future studies to refine destress blasting strategies for Swedish deep hard rock mines.
Copyright (c) 2025 Bekir Genc, Mr Tawanda Zvarivadza, Mr Changping Yi, Professor Dineva, Professor Onifade, Mr Manoj Khandelwal https://creativecommons.org/licenses/by/4.0
Rock mass damage and induced passive depressurization around open pits
Rock mass damage induced by mining increases the fracture frequency and joint aperture width in the pit walls and rock mass behind open pit mine slopes. The depth and intensity of this mechanical damage relative to the pre-mining state is not well understood, and yet is a major factor in the development of slope stability models and operational guidelines. The induced damage can be partitioned into domains or zones. The blast damage zone (BDZ) is essentially a ‘free flow’ rock mass volume which transitions quite rapidly into the excavation damage zone (EDZ) which extends beyond that. In both zones, transient high in-situ water pressures are often linked to unstable slope conditions. Whereas rock damage can enhance passive depressurization in the rock mass, high infiltration rates on the other hand, as one could expect during rainstorm events, will decrease slope stability within the dilated pit rock mass, especially in the BDZ-EDZ, by increasing pore pressures for short periods of time. Ice jacking and freshet are additional factors to consider in (sub) arctic environments and can be exacerbated by unfavorable rock fabric orientation. On a local scale, brittle deformation damage zones, in the form of faults, can contribute to slope instability, or enhanced stability because of slope depressurization depending on their location and orientation relative to the pit shape and the water sources. In this study, the shapes of the damage zones and their anticipated impacts on infiltration and/or passive depressurization are considered for different pit morphologies, rock mass conditions, in-situ stress, and hydrogeological settings. Some unusual hydrological situations, like mining towards rivers and lakes and the potential effects on pore pressures, are also considered. This investigation has resulted in the development of a method to adjust initial hydraulic conductivity values used to estimate transient pore pressure conditions found in rock masses exposed in different pit morphologies and stress regimes, as well as discontinuities’ orientation relative to open faces within the open pit mine. The changes in K values and pore pressures can then be used to determine hydrogeological influence more accurately on future pit slope stability.
Copyright (c) 2026 Anton Bloem, Michael Royle, Ron Uken https://creativecommons.org/licenses/by/4.0
3701 Novel Integrated Holistic Healthy Human Framework: A Special Lens on the Minerals Industry
This paper provides C-suite executives and senior leaders in the minerals industry with a guide on what constitutes a Holistic Healthy Human (HHH) through the introduction of a novel integrated HHH framework with inner holistic health and interpersonal holistic health components unpacked. The value-add of the framework centres around positively enhancing Environment, Social, and Governance (ESG) transformation through a focus on the social enterprise. The proposed novel integrated HHH framework unpacks the vital components and establishes the linkages to the ESG interface as well as to multiple stakeholders. The research employed a targeted approach where 10 C-Suite and senior leaders were interviewed each holding greater than 20 years experience in mining and/or business leadership. The application of this novel integrated HHH framework with the full understanding of its value-add by industry leaders can strengthen the social licence to operate and positively transform the image and opinion of the minerals industry. The applicability of this approach to other industries is currently underway. Keywords: holistic health, human transformation, social enterprise, ESG transformation, systemic approach, minerals industry
Copyright (c) 2026 Bekir Genc, Ms, Dr, Professor https://creativecommons.org/licenses/by/4.0
The practicality of using rock mass classification in a narrow tabular orebody at depth
In the challenging environments of deep-level, narrow tabular orebody gold mines in South Africa, rock mass classification offers a potential method for predicting hazardous areas and optimizing rock support systems. This study evaluates the applicability of various rock mass classification systems, with a focus on the Modified/Mining Rock Mass Rating (MRMR) system tailored for high-stress, deep-level mining conditions. Extensive data collection was conducted at Kusasalethu Mine, involving underground mapping and analysis of the 2020/2021 fall of ground database. The MRMR system was adapted to the unique geological and operational conditions, providing a simplified, user-friendly approach for rock engineering and geology personnel. Results indicate that this adapted MRMR system effectively quantifies rock mass conditions and influences proactive mining adjustments. The study's findings highlight the system's capability to enhance understanding of rock mass behaviour and substantially mitigate the occurrence of rockfalls and ground collapses. Further application and refinement of the system are recommended to continuously improve mining safety and efficiency.
Copyright (c) 2026 Ross van Heerden, Professor https://creativecommons.org/licenses/by/4.0
3690 FLYROCK IN SURFACE MINING–Part 4. GURNEY MODEL FOR BURDEN MOVEMENT, FLYROCK AND ENERGETICS
The Gurney approach to explosive/inert material interaction is adapted to the analysis of face velocity in bench blasting. The model is based on blasthole diameter, rock and explosive density, burden, spacing, linear charge density and a Gurney energy constant. It is validated by comparing its predictions with a set of 20 field measurements of face velocities reported by Chiappetta et al. (1983) in an iron ore mine. The Gurney model links the observed large scatter of measured face velocities to the variation of the Gurney energy constant. This in turn is linked to the variability of gas pressure acting on the burden. These variable pressures are generated when detonation product gases migrate into the extensive and complex fracture network around and between in-row blastholes. The energy efficiency of burden movement can be derived from the model. It is shown that ~7% of the explosive’s chemical energy is available for gas expansion work on the burden; of this quantity, 36% is actually converted to burden kinetic energy. That is, less than 3% of chemical energy is ultimately expended in burden displacement and throw. The model further indicates that the projection of high-velocity (100m/s, say) flyrock is possible only when the path of least resistance through the burden has an effective density far less than the host rock. An equation is derived that identifies the combinations of burden and path densities that may yield flyrock.
Copyright (c) 2026 Dr Szendrei, Mr Simon Tose https://creativecommons.org/licenses/by/4.0
3196 The impact of junior miners on the global supply of high purity manganese sulphate monohydrate for the electric vehicle battery market
The minerals sector continues to draw attention from policy makers who would want to see both old and new mineral projects add value to the minerals in the host country. The current technological development in the leaching of manganese oxide ores to produce a high purity manganese sulphate monohydrate, a compound that is used in the manufacture of batteries for electric vehicles or long life storage cells for the renewable energy market has led to junior mining companies spearheading this technology in new projects across the globe. In this paper, we researched the high purity manganese sulphate monohydrate project pipeline and used projected production volumes and C1 cash costs to construct the industry supply curve for five projects including the K. Hill project owned by Giyani Metals Corporation near Kanye, in the southern part of Botswana. The aim was to determine the ideal conditions that would provide a comparative advantage for further local value addition to high purity manganese sulphate monohydrate and to the end user product. The results showed that while the estimated C1 cash costs would place the K. Hill project as the second highest cost producer from among five projects, it would nonetheless have healthy profit margins due to the high projected price of high purity manganese sulphate monohydrate. The study recommended policy options, which if implemented, could further encourage the exploitation and value addition of battery metals in Botswana.
Copyright (c) 2026 Khaulani Fichani, Larona Sethunya Teseletso, Jacob Kaavera, Tumelo Kgetse Dintwe, Elisha Shemang, Bonny Ignatius Matshediso https://creativecommons.org/licenses/by/4.0
1787 A Limit Equilibrium Approach to the Use of Stability Bunds for the Design of a HDPE-lined Tailings Storage Facility
The addition of a HDPE-liner between the waste body of a Tailings Storage Facility (TSFs) and the natural ground (NG) creates an interface between, inter alia, the liner and surrounding soils on the footprint of the TSF. It is known that low strength materials beneath slopes can cause slope instability. One method, which can theoretically mitigate this instability of a lined TSF, is the addition of stability bunds along the footprint of the TSF. Altering the profile of the footprint to include slope changes, which directly opposes the direction of the failure, creates passive slices in a limit equilibrium analysis. The passive slices actively oppose the movement of active slices, resisting the mobilisation of tailings and resulting in greater active slice forces required to develop a failure surface running along the liner interface. Two scenarios are presented and compared. The first scenario retains the ground profile unaltered and the second scenario includes stability bunds along the ground profile. An in-depth assessment is made on the interslice forces and the interface shear stresses for the defined scenarios. The theoretical background is discussed in greater detail to determine the mechanisms of reinforcement of the bunds.
Copyright (c) 2025 Jean Derek Visagie, Tian Bezuidenhout https://creativecommons.org/licenses/by/4.0
3448 Minable Coal Reserve Estimation by incorporating tonnage and calorific value uncertainties by successive multiple-point and two-point geostatistical simulation algorithms
Estimating reserves and quantifying resources are crucial yet complex tasks in coal mining operations, particularly due to intricate geological formations. Geological uncertainties, including tonnage and coal quality, significantly influence resource and reserve calculations. This research focuses on these uncertainties, specifically calorific value (CV), to numerically characterize resources and reserves in an open-pit coal mine in Indonesia. Using the multi-point geostatistical technique Single Normal Equation Simulation (SNESIM), we simulated the coal seam geometry. A geologically established coal seam served as the training image, generating 20 equiprobable coal models. For CV simulation, 50 realizations were created for each simulated coal seam using sequential Gaussian simulation. Simulated coal seams showed deviations from -0.07% to 5.48% compared to the training image. The CV simulation yielded an average of 5920.29 kcal/kg with a standard deviation of 586.54 kcal/kg, and average CV values ranged from 5305.26 to 6526.55 kcal/kg. For reserve calculation under geological uncertainties, a maximum flow graph theory-based algorithm was used to construct the ultimate pit. This final pit had an average stripping ratio of 1.62 and a CV of 6019.66 kcal/kg. Compared to the deterministic model, the stochastic ultimate pit showed a larger excavation and increased undiscounted cash flow.
Copyright (c) 2026 Fanteri Suparno, Amol Paithankar, Snehamoy Chatterjee https://creativecommons.org/licenses/by/4.0
3627 Evaluating the creditworthiness of a viable artisanal small-scale mining operation
Small-scale miners who operate at the artisanal level in Nigeria struggle to attract formal sources of financing to upgrade their operation to a sustainable form of small-scale mining operation. It has been proven in the body of knowledge that for an investment to attract formal sources of financing, the business must be considered creditworthy by potential lenders. Again, for an investment to be regarded as creditworthy, the credit risks associated with the investment must be bearable for the potential lender. How then can a miner attract formal funding which will help them take the leap from artisanal state to a form of sustainable small-scale mining operation? This study evaluates the credit worthiness of ASM operators using key credit risk parameters identified in the literature and through primary investigation. A quantitative study is then conducted on a sample of 100 ASM establishments in Nigeria to evaluate the effect of these identified credit risk parameters on creditworthiness. It is shown in this study that being a member of a mining cooperative society, which is a form of social collateral, best improves the chances of access to formal financing for miners within the sample group. This underpins the role of social collateral, in both formal and informal economy, and its influence in improving the creditworthiness of a typical ASM operator.
Copyright (c) 2025 Olushola Daniel Eniowo, Moshood Onifade, Hendrik GROBLER, Antoine Floribert Mulaba-Bafubiandi, Ojemeri Sunday Otuogbai https://creativecommons.org/licenses/by/4.0