Developing a compressed air benchmark approach to be used as a metric to identify ventilation shortfalls

Date
2023-11
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Stellenbosch : Stellenbosch University
Abstract
ENGLISH ABSTRACT: Platinum mining contributes significantly to the economy of South Africa. However, deep-level platinum mines in South Africa are facing numerous challenges which is placing strain on the profitability of these mines. One challenge that stood out is the rising electricity cost which is detracting from the price of Platinum Group Metals. This challenge has forced platinum mines to investigate improving the efficiency of electricity consumers. Two utilities that were specifically highlighted are compressed air and ventilation. Compressed air is a critical component in the mining operation and accounts for a large portion of electricity use. It has been estimated that 75% of produced compressed air is wasted because of mismanagement and misappropriation. The wastage stems from leakages, as a result of poor maintenance, mismanagement and misappropriation. To address the low efficiencies in deep-level mine compressed air systems, previous studies have investigated several demand-side management initiatives to reduce the wastage of compressed air. Ventilation, the second utility, promotes an optimised mining cycle and is critical to ensuring that the health and safety standards of mine personnel are adhered to. Mining companies prioritise production considerations over ventilation requirements and as a result, ventilation networks are often inadequate. This often causes compressed air to be misappropriated as an interim solution for cooling working areas underground. Existing studies on underground compressed air wastage and ventilation shortfalls in deep-level mines are limited. Additionally, the effect of ventilation shortfalls on compressed air misappropriation has not been evaluated. Hence, a need exists to determine the relationship between compressed air wastage and ventilation shortfalls. Current methods for addressing compressed air wastage and ventilation inefficiencies, such as benchmarking models, simulations, leak management, and conventional audits, do not specifically target ventilation shortfalls as a root cause for compressed air wastage. Additionally, these studies make use of complicated and limited methods to address compressed air wastage and ventilation inefficiencies. To address the problem identified, the main study objective of this thesis was the development of a new methodology, utilising compressed air wastage as a metric, to identify ventilation shortfalls in a less resources and time-intensive way. A new method was developed that benchmarks compressed air systems in deep-level underground mines to identify and prioritise levels based on the highest compressed air wastage. This newly developed method was further tailored towards ventilation shortfalls, utilising a newly developed Baseload Intensity indicator, to identify the level with the highest possibility of a ventilation shortfall. By localising ventilation shortfalls to specific crosscuts using the crosscut baseload method (in conjunction with the Baseload Intensity indicator), the methodology reduces the resources and time required to identify ventilation shortfalls. The newly developed methodology, with its sub-methods, was applied to two deep-level platinum mines in the North West province of South Africa. The application of the newly developed methodology successfully identified ventilation shortfalls using less resources and time (when compared with conventional audits) on both case studies.
AFRIKAANSE OPSOMMING: Platinum mynbou dra aansienlik by tot die ekonomie van Suid-Afrika. Tog staar die Platinum diepvlak mynbou in Suid-Afrika talle uitdagings in die gesig, wat druk plaas op die winsgewendheid van hierdie myne. Een merkbare uitdaging is die stygende elektrisiteitskoste wat afwyk van die prys van Platinum Groep Metale. Hierdie uitdaging het gelei tot ondersoek deur platinum myne om die doeltreffendheid van elektrisiteitsverbruikers te verbeter. Twee operasionele dienste wat spesifiek uitgelig is, is hoë-druk lug en ventilasie. Hoë-druk lug is 'n kritiese komponent in die mynbou-operasie en maak 'n groot deel uit van die elektrisiteitsgebruik. Daar is beraam dat 75% van die hoë-druk lug wat geproduseer word, gemors word as gevolg van wanbestuur en wanbesteding. Die morsing spruit voort uit lekke,’n direkte oorsaak van swak onderhoud, wanbestuur en wanbesteding. Om die lae doeltreffendheid van die hoë-druk lugstelsels in diep-vlak myne aan te spreek, het vorige studies verskeie inisiatiewe vir aanvraagkantbestuur ondersoek, om die morsing van hoë-druk lug te verminder Ventilasie bevorder 'n geoptimaliseerde mynbousiklus en is van kritieke belang om te verseker dat die gesondheid- en veiligheidstandaard van mynpersoneel nagekom word. In menigde gevalle prioritiseer mynmaatskappye produksie-oorwegings oor ventilasievereistes en as gevolg daarvan is ventilasienetwerke dikwels onvoldoende. Dit lei daartoe dat hoë-druk lug gereeld wanbestee word as 'n tussentydse oplossing vir die verkoeling van ondergrondse werkareas. Bestaande studies oor die morsing van hoë-druk lug en ventilasietekorte in diep-vlak myne is beperk. Die omvattende effek van ventilasietekorte op die wanbestee van hoë-druk lug is nog nie ten volle geëvalueer nie. Daar is dus 'n behoefte om die verband tussen morsing van saamgedrukte lug (as gevolg van wanbestee) en ventilasietekorte te bepaal. Huidige metodes vir die aanspreek van morsing van saamgedrukte lug en ventilasie-ondoeltreffendheid, soos maatstafmodelle, simulasies, lekkasiebestuur en konvensionele oudite, teiken nie spesifiek ventilasietekorte as 'n kernoorsaak vir morsing van hoë-druk lug nie. Hierdie studies maak ook gebruik van ingewikkelde en beperkte metodes om die morsing van hoë-druk lug en ventilasie-ondoeltreffendheid aan te spreek. Developing a compressed air benchmark approach to be used as a metric to identify ventilation shortfalls. Om die geïdentifiseerde probleem aan te spreek, was die hoof doelwit van hierdie tesis, die ontwikkeling van 'n nuwe metodologie wat die morsing van hoë-druk lug gebruik as 'n maatstaaf om ventilasietekorte op 'n minder tyd- en hulpbronintensiewe wyse te identifiseer. 'n Nuwe metode is ontwikkel om die hoë-druk lugstelsels in diep-vlak ondergrondse myne te maatstaaf en te prioriteer gebaseer op die hoogste morsing van hoë-druk lug per mynvlak. Hierdie nuwe metode is spesifiek verder aangepas om ventilasietekorte te identifiseer deur 'n nuwe “Baseload Intensity indicator” te gebruik, om die mynvlak met die hoogste moontlikheid van 'n ventilasietekort te identifiseer. Deur ventilasietekorte na spesifieke “crosscuts” te lokaliseer deur die “crosscut baseload” metode (saam met die “Baseload Intensity indicator”) te gebruik, verminder dié nuwe metodologie, die hoeveelheid hulpbronne en tyd benodig om ventilasietekorte te identifiseer. Die nuwe metodologie, met sy sub-metodes, was toegepas op twee diep-vlak platinum myne in die Noordwes-provinsie van Suid-Afrika. Die nuwe metodologie was op twee gevallestudies toegepas, het die ventilasietekorte suksesvol geïdentifiseer en was minder tyd- en hulpbronintensief (in vergelyking met konvensionele oudite).
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Thesis (MEng)--Stellenbosch University, 2023.
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