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By J. H. C. Pretorius, P. Nelwamondo

"Although South Africa possesses more than 80% of the world’s platinum reserves, its reputation for reliability in supplying platinum to global markets is under threat. This is due to the 49% decrease in output per worker (1999–2014), while the domestic costs have risen by more than 10% annually for the past 5 years. In addition, the continued decline in the commodity price by 38.3% (2012–2016) has resulted in a significant portion of the sector producing at a loss in 2015. The Chamber of Mines (now the Minerals Councilof South Africa) has suggested that solutions to improve productivity and reduce cost pressures are required. This research aims to provide operational excellence through the application of event chain project management (ECPM) to improve productivity and reduce operational costs. A case study was used to carry out research in platinum mines, with data collected using a motion-time study to measure the current efficiency of operations in each mining stope through actual activity durations. The results indicate that through the application of the event chain project management methodology, risks affecting the mining stope schedule can be managed, the efficiency of operations was improved by reducing the time spent on each activity, productivity was increased by shortening the project duration, and operational costs were reduced in the process. IntroductionSouth Africa’s total mining industry production was 4.9% lower in 2016 than in 2015; it decreased by 1.9% year-on-year in December 2016, with the main contributor to this negative trend being the platinum group metals (PGMs) with a drop of 15.1% and contributing -3.8% percentage points (Statistics South Africa, 2016). Although South Africa possesses more than 80% of the world’s platinum reserves, the 8% drop in production output since 2008 has put the platinum mining industry under the threat of being seen as an unreliable supplier to global markets. This decline in production is caused by the 49% decrease in output per worker between 1999 and 2014. In addition, the continued decline in the commodity price by 38.3% from 2012 to 2016 and an increase in operational costs during the same period resulted in a significant portion of the sector producing at a loss in 2015. A turnaround strategy is required to overcome these challenges. The Chamber of Mines has suggested, among others, the need for solutions to improve productivity and reduce cost pressures. The implementation of these solutions will ensure that the PGM industry thrives and reaches its potential of growing production to more than 322 t by 2020 (Baxter, 2016)."

Jan 1, 2018

By B. A. Obadele, R. Machaka, M. L. Raganya, M. E. Makhatha, N. A. Moshokoa

The influence of solution treatment on the phase evolution and tensile properties of Ti-Mo alloys was investigated to assess their potential use in biomedical applications. Phase formation and microstructural evolution were studied using X-ray diffraction (XRD), optical microscopy (OM), scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD). The mechanical properties were characterized by means of tensile tests and bending strength. XRD analysis showed that solution treatment increased the volume fraction of β phase and supressed the α" phase. The microstructures of the as-cast alloys consisted of β equiaxed grains with sub-grain structures of different sizes, while the solution treated alloys comprised β equiaxed grains only except for Ti- 10.02Mo, which comprised needle-like α" structures. EBSD showed an increase in the volume fraction of the ω and α" phases in all the alloys after solution treatment. The elastic modulus and UTS of all the alloy significantly decreased after solution treatment, except for Ti-15.05Mo,whereas the elongation significantly increased. The fracture surfaces of all the alloys after solution treatment indicated more ductile behaviour than brittle

Jun 10, 2024

By W. Jilowa, C. Nguni, M. Simukoko, C. Nampungwe

The upsurge in cobalt price and demand is propelled by high demand from the electronics and electric vehicle industry. Konkola Copper Mines has cobalt occurring with copper in the ratio 1:10 in ore. The ore is treated in the concentrator and recovered at the smelter as an alloy (Cu 70%, Co 4%–7%, 15% Fe). Subsequent processing of the cobalt alloy is challenging, with very few plants able to treat it, leading to marketing challenges. Konkola Copper Mines sought to improve the cobalt alloy by producing a slag that is easier to handle and process in subsequent processes. Cobalt alloy (3.60% Co, 85.4% Cu) was re-melted in a copper bath four times the mass of the alloy. Silica and lime were added for phase separation and fire refining commenced. Following completion of fire refining and after holding the temperature at 1200°C, cobalt-rich slag was skimmed and blister copper was cast into anodes for electrorefining

Jan 1, 2023

By M. Le Roux, Q. P. Campbell, M. Fofana

The determination of densimetric information to predict coal washabilities is an important step in characterising the feed material, as well as the performance of operating plants. However, traditional methods like float-and-sink analysis are hazardous and time-consuming. This is especially true for finer particle size ranges, where very long settling times are required in a medium. De Beers Technologies recently developed a density analyser, known as the RhoVol, for use on diamondiferous kimberlite. Operating over size ranges from 25 mm down to 3 mm, it can determine the mass, volume, density, size and shape of all the particles in a given population and is thus able to provide information about the densimetric distribution on a single particle basis. A study was carried out to compare uncalibrated and calibrated RhoVol results to densimetric and size data obtained using traditional zinc chloride float-sink procedures, for three different coal samples in the size range 3 mm to 8 mm. The results indicate that the RhoVol can be used to provide simple, rapid and safe size-by-washability information for coal, provided proper pre-calibration is done, mainly to account for the effects of particle porosity in the density determination. Keywords: Coal washability determination, RhoVol, densimetric curve

Jan 1, 2020

By D. V. J. W. Groenewald, T. M. Louw, L. Auret, S. M. Bradshaw, A. V. Cherkaev

Unexpected equipment failures lead to financial losses due to production disruption. Time-based maintenance, based on checks over regular time periods, has been employed to minimise disruption. However, the improvements it can offer are limited as it may lead to unnecessary service of healthy equipment or missed failures occurring between service intervals. Condition-based maintenance (CBM) provides a further improvement to equipment reliability by detecting faults and predicting remaining useful life (RUL) based on equipment health monitoring. Its application in the mineral processing industry is hindered due to the high cost of health monitoring equipment. In this study, two stochastic process models, the adaptive auto-regressive model and the gamma process, are compared in their ability to forecast the degradation state and to provide RUL prediction. The gamma process model was found to be effective in both tasks. Due to its simplicity and minimum hyperparameters requirements, it is proposed to use the gamma process as a baseline for comparison with other models. Keywords: Condition-based maintenance, remaining useful life, slurry pump, adaptive autoregressive mode, gamma process

Jan 1, 2020

By M. A. Reuter, N. J. Bartie

Metals make modern societies function, and increasingly, various high purity precious and special metals endow sustainability-driving technologies with specific functionalities. These metals become heavily intertwined within products, complicating end-of-life treatment. To counteract the resulting downcycling and potential depletion of scarce resources, maximising both the quantities and qualities of materials recovered during primary extraction and recycling, processes should be a priority in the pursuit of sustainable circular economy. Adopting a process simulation approach; a digital twin for the life cycle of cadmium-telluride solar photovoltaic (CdTe PV) modules was created. The system comprises an integrated metallurgical production system that produces, among others, cadmium, tellurium, selenium, zinc, copper, and lead, all of which are required to manufacture PV modules. System-wide resource efficiency and environmental impacts are assessed using exergy analysis and life cycle assessment, respectively. Simulation of this large and complex product life cycle at a high level of detail allows for the evaluation of potential system-wide effects of various production, recycling and residue exchange scenarios aimed at maximising the sustainability of the entire system. It diminishes the need to make arbitrary choices about allocation methods for the distribution of environmental impacts in multipleoutput production systems. Furthermore, it demonstrates the key importance of metallurgy in achieving circular economy. Keywords: Circular economy, sustainability, simulation, metallurgy, CdTe photovoltaics, life cycle assessment

Jan 1, 2020

By L. Stamenov, A. Grigoryan, M. Nolte, E. Ayvazov, K. Evtiminova

Dundee Precious Metals Inc. (DPM) owns and operates the Ada Tepe gold mine and processing facility (previously referred to as the Krumovgrad Gold Project) located in south-western Bulgaria. The Ada Tepe mine became the first green filed project in past 40 year in Balkans and one of the few in Europe when it was commissioned during the first half of 2019. The plant produces a high-grade gold silicate concentrate generated through its comminution circuit and staged floatation reactors (SFR’s) while depositing its tailings in a state-of-the-art Integrated Mine Waste Facility (IMWF). This paper presents the successful commissioning, ramp-up and optimization of the Ada Tepe processing plant and how the various challenges, including that of an inexperienced front-line workforce, were overcome. More specifically addressing how the implemented modern processing technologies and the operational readiness program, supported the people and process to achieve the design parameters safely and consistently. Keywords: Commissioning, Optimization, Innovation, Gold mine, Digital mine

Jan 1, 2020

By K. Thambi

The court in Baleni v Minister of Mineral Resources [2019] 2 SA 453 GP and [2020] 4 All SA 374 (GP), deliberated on the protection of rights of a community holding informal land tenure under Customary Law. The contention related to the necessary level of consent needed to acquire a mining right over such land. Moreover, whether consultations with such communities (Section 23, Mineral and Petroleum Resources Development Act 28 of 2002 (MPRDA) or consent (Section 2, Interim Protection of Informal Land Rights Act, No. 31 of 1996 (IPILRA)) was required to acquire such right. The case has a significant bearing on the granting of mining rights in South Africa, and the discretion of the Minister of Mineral Resources (the Minister) in this regard. However, the objectives of the MPRDA and IPILRA do not dovetail, therefore consultation and consent are not mutually exclusive (Tlale, 2020). This note argues that, despite the resounding victory of this case, the peripheral basis surrounding the decision and the various levels of engagement require serious deliberation. Equally, the degree of reliance on the IPILRA requires clarity to avoid aborting the fundamental objectives of the MPRDA. This paper provides considerations and recommendations that may reduce or eliminate the tensions between the statutory and socio-economic rights in the application of the two statutes.

Sep 1, 2022

By R. K. W. Merkle, F. A. S. Reyneke, Z. Harris, P. W. J. Delport

The technological advancements in computing power in the last 30 years have enabled the practical visualization of complex geological environments in three-dimensional (3D) space. 3D models and their application in the mining industry are becoming increasingly important, for example, to identify future exploration areas and targets, for mineral assessment and evaluation, and prediction and planning of future drill-holes. However, acquiring borehole data is an expensive practice, with drilling programmes costing mining companies up to billions of dollars each year. Tighter financial constraints on exploration budgets result in more pressure being put on three-dimensional models to accurately identify future target areas. This article aims to evaluate the potential drilling success of simulated greenfield and brownfield exploration using a 3D geological model created of Leeuwpoort tin mine. These simulations investigate the probability of intersecting a mineralized zone of economic interest and evaluate how the probability is affected when the number of drill-holes and distance from a known intersection changes. Furthermore, these simulations attempt to obtain an indication for the minimum number of drill-holes required for a successful exploration campaign at the mine. The investigation also aims to establish a first-pass attempt towards developing a ‘favoured procedure’ for identifying potential exploration targets for tin deposits with geological and geochemical characteristics similar to Leeuwpoort. The results for the ‘favoured procedure’ established are statistically tested using the ‘bootstrapping’ method. By simulating various exploration scenarios, the study also emphasises the importance of predicting successful drilling, which aids in budgeting for drilling programmes as the minimum number of drillholes needed for a specific exploration project can be determined.

Feb 2, 2022

By R. B. Khumalo, M. S. Nyarela, R. C. Nemathithi

Palabora Mining Company is one of the largest low-grade copper mines globally. The mine uses block caving for the extraction of the orebody. This paper enumerates the drawpoint loading strategies for the overall head grade improvements, particularly for a block that is nearing depletion. A comprehensive literature review of various considerations relating to improving productivity in block caving is presented to contextualize the draw control in caving. From this study, an optimized draw control strategy is presented, which focuses on three parameters that include grade distribution, loading compliance, and tonnage splits per sector. An empirical method based on the relational study between various parameters is used to outline the key criteria to be used in the optimization of drawpoint loading in block caving.

Nov 30, 2022

By G. Bueno, L. M. Tavares, T. M. Campos

Iron ore pellet feed pressing has been one of the first and most successful applications of High- Pressure Grinding Rolls (HPGR) in the minerals industry. Vale S.A. has been one of the pioneers in this application, currently with six HPGRs in operation in the pelletising plants of the Complexo de Tubarão (Brazil). In spite of the important advances in the technology, risks still exist when scaling-up the process from small-scale information. The present work takes advantage of the recent advances in the mathematical modelling of the HPGR performance, using the population balance model to evaluate the modified Torres and Casali model prediction in iron ore pellet feed pressing for different scales of operation. Results are presented that compare the HPGR performance in different operational scales for iron ore pellet feed pressing, demonstrating the confidence of this model-based approach for scale-up to full-scale HPGRs used in pressing iron ore concentrates. Keywords: Scale-up, HPGR, pellet feed, modelling, simulation

Jan 1, 2020

By V. Ross

"Bench-scale flotation tests play a major role in the geometallurgical process value chain. Despite their apparent simplicity, these tests pose pitfalls in terms of operation, as well as the interpretation and modelling of results. In this paper we highlight key aspects to consider in generating accurate and reproducible experimental results, and critically review some assumptions relating to the estimation of entrainment and froth recovery. We subsequently focus on first-order equations to model kinetics and propose a method that accounts more realistically for the decay in kinetics over the duration of a float, and the contributions of froth stability and hence mass pull. The method was applied to three case studies on platinum group metal (PGM) ores and matched or outperformed first-order, two-component models. Also, it allows for a deeper analysis of the integrity of the bench-scale flotation results. IntroductionGeometallurgy is a structured, multidisciplinary approach that integrates key data from the geological, mining, mineralogical, and metallurgical aspects of the value chain to construct spatial models of an ore deposit such that the overall economic benefit and sustainability of an operation can be optimized. Process geometallurgy is aimed primarily at enhancing metallurgical efficiency and plant throughput by the application of appropriate mining and processing strategies, as well as supporting production planning and operational strategies to reduce the impact of highly variable ores. With flotation being the dominant concentrating process in the mineral value chain, the bench-scale flotation test is an important characterization tool – a relatively cheap, simple, and rapid way to obtain key information about the ore and its amenability to economic extraction of valuable minerals. This includes the evaluation of different ore types and the implications of mineralogical composition and texture for comminution and floatability, the effect of the grinding environment on the liberation of minerals, the electrochemical environment in the pulp (Bradshaw et al., 2006), the screening of reagents to improve floatability (Ekmekci et al., 2003), and the role of hydrodynamics in the recovery of valuables and the entrainment of gangue (Amini et al., 2016; Wang et al., 2016). It is also a critical tool in auditing the performance of a flotation plant by hot floats, paving the way for concept and feasibility studies and providing essential data on kinetics for the purposes of scale-up, optimization, and simulation of flotation circuits."

Mar 1, 2019

By J. Sepulveda

"Despite the recognized influence of product fineness on line capacity and downstream process performance, few mineral concentrators today use particle size measurement of the final product in automatic control applications for particle size. ‘Near-line’ particle size instrumentation has existed for decades and is utilized in modern concentrators, but low availability and measurement frequency, due to problems with slurry sampling and transport systems, make these technologies unreliable for use in automatic control. An innovative technology for real-time particle size measurement on individual hydrocyclones, named CYCLONEtrac™ PST (particle size tracking), has been developed by CiDRA Minerals Processing, and proven in commercial installations, demonstrating near 100% availability with minimal maintenance requirements, thus overcoming the limitations of previous technologies. Potential stakeholders require convincing, reliable information regarding the economic value delivered by automatic grind control projects. In this paper we present a methodology for estimating such value with the CYCLONEtrac™ PST technology, and demonstrate unique opportunities to improve process stability and performance. Based on actual plant data accumulated over time, the evaluation approach assesses and highlights the significant potential process improvement that can be expected with the particle size tracking technology. As an extension of previous work, in this paper we present the key operating criteria for optimizing the production of valuable metals and increase mill throughput by identifying the optimal grind size. As this requires operating closer to the process boundaries, accurate real-time particle size measurements, such as those provided by the CYCLONEtrac™ PST system, become essential for achieving the maximum potential value from every operation. For further illustration, data from three different copper plants is compared.Introduction Owners and operators of mineral concentrators constantly search for the most economically attractive way to increase the output of valuable metal. A logical approach is to identify a key parameter that has the greatest impact on the performance of multiple stages of the process and then use a holistic analysis methodology to determine how this key parameter can be controlled to optimize the final output.Particle size is widely recognized as such a key parameter; however, very few concentrators today use real-time particle size measurements for automatic control of the final product size due, to a large extent, to the inherent limitations of existing technologies. ‘Near-line’ particle size measurement instrumentation, which has been used for decades, typically suffers from low availability because the fundamental measurement technologies were developed for other, less demanding industries and then adapted to the harsh environment of the typical mineral concentration process. An outline of the key differences among the available technologies used for particle size measurement in comminution circuits has been completed in previous work, and plant data has proven the benefits of measurements on individual cyclones – something that, until now, has not been possible (Cirulis, 2017)."

Nov 1, 2018

By G. Akdogan, Q. G. Reynolds, S. J. Baumgartner

A computational model of a submerged arc furnace (SAF) used in the production of ferrochrome is presented. The model‘s intended use is to investigate the extent to which intrinsic and extrinsic properties of the raw materials affect burden distribution and electrical resistance within the furnace. The model is built on the discrete element method and calculates the mechanical interactions of particle distributions resulting from the flow motion of typical raw materials used in the smelting of chromium ore. This model excludes the effects of thermodynamics, furnace chemistry, and heat transfer. It illustrates how the consumption of materials (chromite pellets, flux, and reductant) is affected by changes in electrode length, reductant fractions, and reductant sizing and density during the formation of a reductant bed. The resistance calculation algorithm developed by Mintek was applied to construct networks developed from particle contacts, which can quantitatively generate estimates of the electrode-to-electrode and electrode-to-bath electrical conduction conditions.

Apr 16, 2024

By S. Hlajoane, L. S. Mokhahlane

The demand for rare earth elements has increased around the world due to their application in a variety of technological advancements. Previous studies have evaluated the potential of the rare earth elements and yttrium (REY) hosted within the Permian coal deposits of the main Karoo Basin (MKB) in Southern Africa. However, not a lot of scientific research has gone into the Triassic coal deposits. The Triassic coals in South Africa were the first coals to be exploited for their thermal use in the 1880s, but the discovery of the higher rank and more abundant Ecca coal deposits led to the Triassic coals remaining largely unexplored. The demand for rare earth elements has sparked interest in these coal deposits as potential sources for valuable minerals. Late Triassic coal deposits in Lesotho have previously not been well documented and these low-rank coals can be a potential source of rare earth elements. This study aims to characterize and evaluate the potential of REY in the Taung coal deposit, southwest of Lesotho. Coal and associated argillaceous samples from the Taung coal deposit were analyzed using microscopic petrography for coal characterization and an inductively coupled plasma mass spectrometry (ICP-MS) to determine the amount of rare earth elements. Taung coal is classified as middle medium rank D bituminous coal. The total REY content in Taung coal and its associated rocks range from 162.9 ppm to 855.1 ppm, which is significantly higher than the upper continental crustal (UCC) average. The average critical REY concentration of samples from the Taung coal deposit is 189.4 ppm, which is three times higher than that of the Chinese Bayan Obo deposit. Samples classified as very promising and promising because of their outlook coefficients, are found to contain up to 77% of critical REY. It is envisioned that the area could be a prime deposit for these REY.

Nov 6, 2024

By O. Koatlhai

Mine closures have traditionally prioritised environmental rehabilitation, often overlooking the deep socio-economic disruptions that follow, particularly in mining-dependent communities. This paper argues that mine closure should not mark the end of prosperity but rather the beginning of a sustainable transition. The coproduction model, which integrates community participation, governance, and economic planning, offers a transformative approach to closure planning. Drawing on case studies from Ghana, Zambia, and Indonesia, this research examines the successes and failures of past closures, highlighting the critical role of stakeholder engagement, skills development, and economic diversification. By incorporating emerging technologies such as AI-driven economic forecasting, blockchain for governance transparency, and decentralised finance (DeFi) models, mining companies can ensure a just and sustainable post-mining future. This study challenges outdated closure models and presents a forward-looking strategy that sees mine closure not as an endpoint, but as a catalyst for social resilience and economic transformation. It underscores the need for policy reforms, stronger governance, and investment in alternative industries to prevent mining towns from becoming economic wastelands. By shifting the paradigm from remediation to regeneration, this research calls for a new era of mine closure planning that puts people and prosperity at its core.

Apr 25, 2025

By J. Guerrero, O. Pavez, N. Toro, A. Nazer

In the 19th century, mining in northern Chile was of great economic importance. Today, the ruinsof the copper smelters and abundant fragments of refractory bricks from their furnaces remain. Therefractory materials have not been previously studied. the origin, physical and chemical properties, and compressive strength of 10 different samples of historical refractory bricks collected on-site were investigated. The characterization results showed that the bricks are silico-aluminous, unlike the magnesium-chromium bricks used by current foundries. It was determined that 90% of them were produced in the UK and 10% were manufactured in Chile. The phases present are mullite, quartz, cristobalite, and tridymite, and the chemical composition corresponds mainly to SiO2. The compressive strength of the historical bricks is similart to those currently used,. These results may contribute to the knowledge of the 19th century mining and metallurgical historical heritage of Chile and the UK.

Jul 5, 2023

By V. van der Merwe, C. W. Siyasiya

"A petrochemical company experiences premature thermal fatigue failure of the casting moulds used in catalyst production. The aim of the project was to find an alternative alloy that would outperform the current low-alloy cast steel used for the moulds. Based on their thermo-fatigue properties, 3CR12 ferritic stainless steel and H11 tool steel were chosen for testing and comparison with the currently used BS3100 B7 cast steel. Samples of each material were subjected to temperature cycling in a Gleeble 1500TM thermo-mechanical processing simulator, followed by surface analyses. The main parameters derived from the test work were the total true strain, the hot strength of the materials, and the number of cycles to failure. Additionally, the coefficient of thermal expansion for each material was measured using a Bähr dilatometer. H11 tool steel yielded the best performance by way of having the fewest surface cracks, the lowest total true strain per cycle, the most cycles to failure, the highest hot strength, and the lowest coefficient of thermal expansion.IntroductionThe Catalyst Manufacturing Plant (CMP) is a dusty environment with temperatures higher than ambient. Molten mill scale (magnetite, Fe3O4) is tapped from the electric arc furnace into the casting moulds at temperatures close to 1600°C. After 10 seconds the magnetite is quenched with a water spray for 50 seconds to a minimum temperature of 400°C. Sometimes there is residual water in the pans from the cooling fog process (water sprays) in the empty mould. In a typical plant, the factory produces 40–44 batches a day containing between 150–300 moulds, depending on the time required for the specific batch (Buchholz, 2014). The typical batch in the CMP usually weighs about 6 t. The thickness of the tap, speed of the casting belt, and tilting angle all affect the number of moulds per batch.One of the main problems faced during the molten mill scale casting is the premature failure of the casting moulds. Cracks initiate on the surface of the mould, which is in contact with the hot catalyst, and propagate into the interior of the mould. Cracks are generally concentrated in the middle area of the mould where the catalyst makes first contact with the mould, and which experiences the highest temperature fluctuations. This suggests that the cracks are caused by thermal fatigue during the casting process."

Jan 1, 2016

By J. G. M. Mukoya, B. Adebayo

"This work was carried out to determine the influence of rock properties and drilling machine parameters on the penetration rate at the SJ pit of Rössing Uranium Mine, Namibia. Rock properties (uniaxial compressive strength, tensile strength, and modulus of elasticity) of samples collected were determined in the laboratory. Drilling experiments were conducted in which feed pressure, air pressure, rotary speed, weight on the bit, and torque were varied to measure their effect on the penetration rate. The uniaxial compressive strength varied from 90–180 MPa for layered marble-quartzite and banded gneiss. Increases in feed pressure, weight on the bit, and rotary speed beyond the optimum level led to a decrease in penetration rate and caused the drill bit to ‘stall’. Results of the study revealed that penetration rate increases with an increase in the feed pressure and air pressure. After reaching a maximum value, the penetration rate begins to decrease despite increasing feed pressure. A very high torque causes the drill bit to stall, since the feed pressure is too high and the air pressure is not sufficient to remove the cuttings from blast-hole at maxium bailing velocities. The average penetration rate varied from 19 to 45 m/h for phase 2 of the pit, and from 17 to 68 m/h for phase 3. The optimum drilling machine parameters obtained in phase 2 and phase 3 were slightly lower than those currently being used at the mine. The trials of the optimum machine parameters will assist in reducing the cost of drilling, which varied from N$29.48 to N$36.31 per metre for the tricone bit. IntroductionDrilling and blasting contribute most to the operational cost in opencast mining and have the potential to influence the cost of downstream operations (Aipanda, 2011). The drillability of rocks depends not only on the rock properties, but also on the drilling tools and operational variables. In rotary drilling, rotational speed, thrust, and flushing are the operational variables, and are known as the controllable parameters. Rock properties and geological conditions are the uncontrollable parameters. Although, many attempts have been made to correlate drillability with rock properties, the rock characteristics affecting rotary drilling have not been entirely defined (Hartman, 1962; Kahraman, Bilgin, and Feridunoglu, 2003). The drill bit is forced into a rock surface from the rotary power head, hence creating stresses and cracks at the bit-rock interface. The performance of a particular bit in any formation i"

May 1, 2019

By S. Dey, C. Bhar, S. K. Mandal

Loading and hauling of ore and waste are the key operations of an opencast coal mine and entail a high operational cost. The productivity of a mine can be increased by reducing the cycle time of loading equipment as well as utilizing dumpers optimally. In this paper we discuss the impact of rock type, bucket fill factor, rock fragmentation, the height of the cut, and angle of swing of the bucket on shovel performance. A time study is conducted on shovels in an opencast coal mine with experimental blasts of rocks to assess the impact of different factors on the performance of the shovel. Based on the data, the authors applied multiple regression (MR) and artificial neural network (ANN) techniques to develop different models for the prediction of the shovel cycle time. Developed models are validated by comparing the predicted data with actual field data. With the help of the best model, the plausible fleet size is determined in order to utilize the shovel and dumper optimally and to improve the performance of shovel–dumper operation.

Oct 1, 2022