FEATURE
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.
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.
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. DEPARTMENT OF MINING ENGINEERING
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.
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ANNUAL REVIEW 2019/20
