Improving compressed air networks on PGM mines in South Africa through continual monitoring and reporting

Abstract

The South African platinum group metals (PGM) mining industry faces significant challenges due to the energy consumption of compressed air networks, which accounts for approximately 21% of total electricity usage. With rising electricity costs and fluctuating commodity prices, PGM mines must prioritise sustainable efficiency improvements and cost reduction strategies to remain profitable. A method explained in this document shows a potential annual cost saving of R1.6 billion on compressed air networks in the South African PGM industry (across 26 identified mines). This finding further emphasises the necessity of implementing effective efficiency improvement initiatives. A major contributor to these significant potential savings is the mismanagement and inefficient use of compressed air on the demand side. Issues such as leakages and using compressed air for ventilation in hot underground working areas continue to plague the industry. Previous studies have investigated various demand-side improvement initiatives in an attempt to address these inefficiencies. While extensive research has been conducted on improving the efficiency of compressed air networks in the South African mining industry and identifying inefficiencies in these complex underground networks, there is a noticeable gap in the literature regarding the continual monitoring and reporting of compressed air network performance to improve the demand-side. This study aims to fill this gap by proposing a solution to improve the demand-side efficiency of compressed air networks in the South African PGM mining industry through continual monitoring and reporting. This study presents a practical solution that was applied to a mining group in the South African PGM mining industry. The main objective of this research study was to develop a solution using continual monitoring and reporting to improve the demand side of compressed air networks in the South African PGM mining industry. This solution focused on identifying, acquiring and validating data, as well as developing reports for daily and weekly monitoring and a procedure for continual monitoring and reporting on inefficiencies. Additionally, it aimed to ensure progress is tracked in rectifying identified inefficiencies. The objectives of this study were achieved successfully, demonstrating that continual monitoring and reporting of compressed air network performance on the demand-side can yield significant cost savings. This potential for financial benefit highlights the practicality and effectiveness of the proposed solution. The solution can be utilised to monitor and identify inefficiencies such as malfunctioning instrumentation, which saved approximately R150 000 over five weekdays in one case study. When initiatives are implemented with managerial support - such as closing control valves during the blasting period - an annual energy reduction of up to 5.6 GWh, translating to approximately R10.6 million, may be realised. Furthermore, the developed solution proves effective for underground operations, potentially leading to an annual reduction of 3.7 GWh or R7.2 million through efficiency initiatives focused on improving ventilation controls in underground working areas.