A new simulation-based methodology for pro-active planning in deep-level mine ventilation systems to identify and mitigate hazards

Date
2024-03
Journal Title
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Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: Deep-level mining is present in various countries around the world. Gold production continues to decrease, and this places strain on the gold mining industry in South Africa. The depleting gold reserves meant that the existing deep-level gold mines had to expand deeper into the earth’s crust. Consequently, effective ventilation of deep-level mines is challenging. Deep-level mines rely on complex and dynamic ventilation systems to supply adequate air to underground workers. Changes to these systems are implemented to enable the expansion and deepening of the mines. These changes could cause certain hazards underground. The three main hazards that occur are high temperatures, gas accumulation and dust pick-up. It is therefore crucial to ensure that these hazards are prevented through effective planning. Digital twinning is a cutting-edge technology that simplifies the simulation and planning of the entire deep-level mine ventilation system. Currently, a problem persists in the absence of a concise strategy for identifying and mitigating hazards in life-of-mine planning, specifically when utilising a calibrated digital twin. Therefore, a systematic literature review was conducted to confirm this unique research opportunity. Additionally, a need is identified to determine the frequency of planning. There are currently two planning methods, namely incremental and end-state planning. The case study research methodology was utilised to develop a new strategy that uses a calibrated digital twin to identify and mitigate hazards in the planning of the life-of-mine. The strategy will then be verified in two parts, firstly verifying the strategy itself and secondly by utilising it in the two mentioned planning methods. The first verification case study implemented the hazard identification and mitigation strategy on a deep-level gold mine. The study produced a calibrated model with an accuracy of 95%. The calibrated model was then expanded according to the strategy and was used to identify various problem areas where high temperatures and insufficient airflow were present. These hazards were then mitigated, and sufficient ventilation was supplied throughout the three-year life-of-mine plan. The second verification case study implemented the hazard identification and mitigation strategy in both the incremental and end-state planning method. This enabled the comparison of these planning methods to evaluate the impact of the lower frequency of planning. This study highlights the significance of effective planning to minimise delays to ensure continuously safe working environments during the entire life-of-mine, rather than just at specific stages in the life-of-mine plan. Therefore, the developed solution in this research study can be used as a new simulation-based methodology for pro-active planning in deep-level mine ventilation systems to identify and mitigate hazards. The original contributions of the study include: • The development of a new strategy used in deep-level mine ventilation system life-of-mine planning. • The utilisation of a calibrated digital twin to identify possible problem areas in life-of-mine planning. • The reproducibility of the implementation of the strategy on all deep-level mines. • The improvement in the management and planning of a deep-level mine ventilation system. • The identification of which planning method is applicable for various applications.
AFRIKAANSE OPSOMMING: Diepvlakmyne is teenwoordig in verskeie lande oor die wêreld. Die kontinue afname in goud produksie plaas druk op die goudmynbedryf in Suid-Afrika. Die uitputting van goudreserwes beteken dat bestaande diepvlak goudmyne moet uitbrei deur dieper in die aarde se kors in te gaan. Gevolglik is effektiewe ventilasie van diepvlakmyne uitdagend. Diepvlakmyne maak staat op komplekse en dinamiese ventilasie stelsels om genoegsame lug te voorsien aan ondergrondse werkers. Gereëlde veranderinge aan hierdie stelsels is geïmplementeer om die uitbreiding en verdieping van myne in staat te stel. Hierdie veranderings kan veroorsaak dat sekere gevare teenwoordig is ondergrond. Die drie hoof gevare is hoë temperature, opbou van gas en die skep van stof. Dit is daarom krities om te verseker dat hierdie gevare voorkom word deur effektiewe beplanning. Digitale tweelinge is baanbreker tegnologie wat die simulasie en beplanning van volledige diepvlak ventilasie sisteme vereenvoudig. Tans is daar ‘n tekort aan ‘n bondige strategie om gevare te identifiseer en die moontlikheid daarvan te verminder in die myn se lewensiklus (lewe-van-myn) beplanning, spesifiek met die gebruik van ‘n gekalibreerde digitale tweeling. Daar is daarom ‘n sistematiese literatuuroorsig gedoen om die unieke navorsing geleentheid te bevestig. Daar is ook ‘n behoefte om die frekwensie van beplanning te bepaal. Daar is tans twee beplannings metodes naamlik inkrementele- en eindstaatbeplanning. ‘n Gevallestudie navorsingsmetodologie was gebruik om ‘n nuwe strategie te ontwikkel wat gebruik maak van ‘n gekalibreerde digitale tweeling om gevare te identifiseer en die moontlikheid daarvan te verminder. Die strategie word dan geverifieer teen die behoeftes en dan gevalideer deur die strategie toe te pas in die twee beplanning metodes. Die eerste gevallestudie implementeer die gevare identifikasie en versagting strategie op ‘n dieplakgoudmyn. Die studie het ‘n gekalibreerde digitale tweeling geproduseer met ‘n akkuraatheid van meer as 95%. Die gekalibreede model word dan uitgebrei volgens die strategie en is toe gebruik om verskeie probleem areas te identifiseer waar hoë temperature en onvoldoende lugvloei teenwoordig is. Hierdie probleem areas is toe aangespreek en genoegsame ventilasie word voorsien regdeur die drie-jaar lewe-van-myn plan. Die tweede gevallestudie implementeer die gevaar idenfikasie en versagting strategie in beide die inkrementele- en eindstaatbeplanningsmetodes. Dit het die vergelyking van die twee metodes gemaak om die impak van laer frekwensie beplanning te evalueer. Hierdie studie beklemtoon die belangrikheid van effektiewe beplanning om vertragings te verhoed en deurlopend veilige werksomstandighede gedurende die hele lewe-van-myn, eerder as net spesifieke stadiums in die lewevan-myn plan. Daarom kan die ontwikkelde oplossing in hierdie navorsingstudie gebruik word as ‘n nuwe simulasie gebasseerde metodologie vir proaktiewe beplanning in diepvlakmyn ventilasie sisteme om gevare te identifiseer en te versag. Die oorspronklike bydraes van die studie sluit in: • Die ontwikkeling van ‘n nuwe strategie gebruik in diepvlakmyn ventilasie sisteem beplanning. • Die gebruik van ‘n gekalibreede digitale tweeling om probleem areas te identifiseer in lewevan-myn beplanning. • Die reproduseerbaarheid van die implementering van die strategie op alle diepvlakmyne. • Die verbetering van die bestuur en beplanning van ‘n diepvlakmyn ventilasie sisteem. • Die identifikasie van watter beplanningsmetode vir verskeie toepassings van toepassing is.
Description
Thesis (PhD)--Stellenbosch University, 2024.
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