A multi-layered non-linear methodology to introduce alternative handheld drilling technology in tabular narrow reef mines

Abstract

Any mining operation that is unwilling or unable to adopt technological advancements will face profitability challenges throughout its lifespan. This statement is especially relevant to mature gold mines in South Africa that are air-reliant on compressed air rock drills. These operations were mainly sunk in the twentieth century, when compressed air drilling systems were the only effective method for drilling blastholes in narrow reefs. At that time, electricity was inexpensive and readily available, and the production blocks were close to the shafts. In the twenty-first century, the opposite is true, as compressed air drilling systems at certain mines are no longer techno-economically viable. Available literature indicates that alternative handheld drilling technologies exist but are rarely adopted due to insufficient implementation and change management methodologies. This study employed the case study research methodology to develop a unique pragmatic approach to implementing alternative handheld drilling technologies in mature, deep-level, tabular narrow reef gold mines. The agile method enables mine management to anticipate the urgency for alternative drilling technology before the need becomes a necessity. Past failures were analysed to identify hidden risks and opportunities that had been previously overlooked or underestimated. These failure drivers were used as strategic guidance to formulate the study specific method objectives. Kotter's change framework provided eight purposeful steps to introduce the alternative drilling system. A non-linear, multi-layered methodology is proposed, in which each step hosts an array of strategies methodically crafted to be practical, actionable, and useful. To verify the urgency of the change, the method initiates the change process by providing means to distinguish between correlation and causation. Once verified, a simple change vision is crafted to highlight the benefits to all stakeholders. The vision aims to establish trust in the change idea while aligning interests, ultimately promoting stakeholder buy-in. Responsibility structures ensure that every actionable task has an accountable person assigned. Critical upgrades to the water and electrical networks may be required to support the alternative drilling system. However, methodologies for assessing the mine's standard network support capability were not found in the literature. To fill this gap, this study developed a novel infrastructure evaluation methodology to identify the network's limitations and required upgrades. To implement the change, this study proposes a non-linear experimental approach that does not rely on a finite start and end state. In fact, the change idea is first tested on a small scale to validate its change benefits before committing to large-scale roll-outs. This allows for real-world feedback and prevents impulsive decision-making, which can lead to costly mistakes. By balancing ambition with caution, the method provides a strategy to prioritise crews during the roll-out phase based on their actual drilling performance. A continuous improvement strategy was integrated into the method to enable stakeholders to analyse the change results and formulate and implement improvement opportunities. The improvement strategy is based on the 80/20 principle and prioritises actionablem items by recognising that 20% of effort can yield 80% of the improvement. A mature gold mine was used as a case study to validate the proposed methodology. Hydropower was selected as a feasible alternative drilling technology, and the method was iteratively applied to convert all the stoping crews from pneumatic to hydro drilling. The continuous improvement loop enabled the project team to implement low-risk, viable adjustments to the change process, resulting in a projected 17% improvement in production. This improvement translates into an additional revenue stream generated of R760 million per annum. Ultimately, all the compressed air stoping crews were converted to localised and micro hydropower, making it the first mature South African gold mine originally designed to operate with compressed air stopes to achieve this outcome. This result validates the method's effectiveness in addressing the study's need for an implementation and change management methodology to introduce alternative drilling technology in narrow reef gold mines. The study concludes with an overview of the key lessons learned to achieve this outcome. The novel method proposed by this study is not simply based on theory; rather, it is supported by a firm foundation of real-world lessons learned and validated using a real-world case study to confirm its effectiveness.