Young mining researchers

Young researchers ensure the sustainability of the Department

The future of the Department of Mining Engineering depends on the inclusion of young researchers of a high calibre who are representative of the mining sector in terms of race and gender. Two of these young researchers, who are presently enrolled for their PhD degrees in Mining Engineering, are Jennifer van der Walt and Larrance Ngwenyama.

Jennifer van der Walt

Jennifer is currently employed as a part-time lecturer and researcher in the Department. In 2015, she conducted a research study into noise-induced hearing loss (NIHL)-related noise emissions from hand-held rock drills in underground platinum mines as a finalyear research project. She graduated in 2016 and worked as a graduate mining engineer in Rio Tinto’s Graduate Programme, based in Richards Bay (Richards Bay Minerals).

Since 2016, Jennifer has used every opportunity to collaborate with experts in the mining industry through projects at Richards Bay Minerals, “on-the-job” training in mine development and by attending seminars and conferences to increase her knowledge of the mining industry. In 2017, she conducted a study on flyrock mitigation and safe blast clearance distances, which included collaboration with industry partners. Jennifer completed her MEng Mining Engineering degree cum laude.

Between 2018 and 2019, she was engaged in the research and development of a tool concept aimed to quantify the motion (or trajectory) of flyrock on surface mines using the latest available technologies. She is currently registered as a PhD student in the Department under the supervision of Prof William Spiteri, and is conducting a study to further develop the conceptual tool to quantify the motion of random flyrock on mines using the latest technologies. Flyrock remains a significant risk to the health and safety of the mine’s employees and infrastructure, as well as the safety of the neighbouring communities and their property. Losses and damages can result in significant financial and reputation consequences. Several researchers have identified major gaps in the knowledge related to flyrock, specifically because of its random nature. The lack of research relating to the relationship between blast design parameters and the risk of flyrock motivated Jennifer’s flyrock project.

Research published since 2010 has identified the challenge of flyrock predictions being site-specific, and therefore not applicable to other environments. The focus of Jennifer’s project was to develop a concept to quantify the flight path of the flyrock resulting from a blast. The motivation behind it was to enable future researchers to quantify the impact of different blast design parameters on the measured flyrock.

After a comparative analysis of various technologies, photogrammetry was selected as the foundation of the proposed concept tool, which comprised three main phases: data acquisition, image processing and data analysis, and data interpretation. To date, progress has been achieved with the first two phases. In Phase 1, all the objectives have been met. However, there are still areas that need refinement, specifically regarding the placement of the cameras in the field. Phase 2 saw the proof of concept in a controlled environment using a clay pigeon as the projectile. The process of calibrating the lenses has been established. However, further optimisation is possible. Point-cloud data was successfully generated in the concept test, but converting the image data from subsequent quarry test blasts is still being refined.

Results to date have given a positive indication that the concept is viable and that additional work will prove the technology functional. Ultimately, it is envisioned that this tool can be used by mines or research teams for predictive purposes, or by education and training institutions to visualise blasts and flyrock in virtual reality.

YOUNG MINING RESEARCHERS

Larrance Ngwenyama

Larrance currently works at South32, a South African coal mining company, as a graduate in training. After graduating from the Department in 2015, he decided to further his studies and pursue a career in research. He completed his honours degree in 2016 and joined the Department as a contract lecturer and junior researcher. In this capacity, Larrance was a presenting author and delegate at various conferences, including the 2016 New Technology and Innovation Conference of the Southern African Institute of Mining and Metallurgy (SAIMM), the third and fourth Young Professionals Conference, and the 2019 International Mine Health and Safety Conference. He published his first journal paper with SAIMM in 2017.

Larrance completed his master’s degree (cum laude) in 2018 under the supervision of Prof Ronny Webber-Youngman. As an aspiring junior researcher, he was involved in a number of consulting research projects with the Department’s Mining Resilience Research Centre. One of these was the development of a Missing Person Locator System (MPLS) for the Mine Health and Safety Council (MHSC). He played a huge role in the completion of the MPLS, and the MHSC invited him to visit a mine in which miners were trapped underground to share insights from the research project to assist in locating the trapped miners. As a result, Larrance decided to focus his master’s research extensively on trying to find the most effective, applicable and suitable person locator system for the South African mining industry. He strongly believes that an innovative and fit-for-purpose MPLS will make a significant contribution to the safety of employees in the mining industry and save lives.

As part of his envisaged PhD research, Larrance aims to develop an innovative missing person locator system with the involvement of the MHSC. He also plans to build a prototype of his PhD research product through a multidisciplinary approach with other departments, such as the Department of Electrical, Electronic and Computer Engineering. Mining is often regarded as one of the most dangerous, hazardous and risky work environments. This is often attributed to the continued occurrence of accidents that result in serious injuries and fatalities. Among these accidents, a significant number of fatalities are associated with miners going missing in underground mines after accidents.

Fatalities related to missing persons are often incorrectly reported, since investigations have shown that miners can survive the initial event and become trapped or lost in unknown locations for an extended period of time after evacuation procedures. While trapped underground, the miners can succumb due to a lack of life-sustaining necessities such as water, food and fresh air, or as a result of injuries that they sustained during the initial event. Studies showed that medical assistance must be provided within an hour of an accident to stand a good chance of saving lives.

Evaluations of accidents related to missing persons show that these fatalities could have been prevented by means of an MPLS that can quickly provide the accurate locations of the missing persons. This became critical after realising that the miners are often trapped in areas that are not life-sustaining. The unavailability of information regarding the locations and exact number of persons trapped underground forces rescue teams to search for the missing miners in random areas and/or presumed locations. Search-andrescue operations therefore often last longer than necessary or fail. In some cases, the missing miners are presumed dead without significant evidence.

This study examined various systems that have the potential to locate missing persons after accidents. These systems were categorised as through-the-wire, through-the-air and throughthe-earth communication technologies. The main purpose of this study was to make the mining industry aware of the systems, technologies and devices available in the market for the purpose of locating missing persons. It emphasised the need and value of the potential MPLS through the awareness of system capabilities and limitations rather than recommending a specific system for the industry. It was recommended to use the findings from this study to develop an innovative MPLS that can provide solutions to the shortcomings of the available systems based on the evaluations conducted.