There was nothing out of the ordinary with lunchtime in Minas Gerais, a state in the north of Southeastern Brazil on 25 January 2019. The peace and tranquility lasted until 12.28pm. Then tragedy struck (pictured above) and it came in the form of 12 million cubic meters of mine iron ore released after a dam at the Corrego do Feijao mine burst. Traveling at up to 120 km/h, the tailings wave hit the mine’s loading station, its administrative area, including a cafeteria where many workers were enjoying lunch at the time. The slurry then went hurtling on a 7km downhill towards Rio Paraopeba and left 248 people dead in its wake. The deadly slurry reached the Rio Paraopeba, killing all life in the river and destroying infrastructure for the production of drinking water.
Since 1961, there have been over 60 such incidents of tailings dam failure all over the world, which has led to the loss of over 500 people. Mokgadi Mahlatse Nchabeleng, an MSc engineering student at the University of Witwatersrand, is doing research on how to put in end to these tragedies. Nchabeleng is investigating the consolidation properties of mining ore residue, also known as tailings. As part of her research, she will measure the compressibility and consolidation characteristics of non-plastic tailings at stress levels that exist in tailings dams. Nchabeleng hopes that her findings will help the local mining industry to ensure that similar accidents do not occur in SA. Nchabeleng is the co-author of an article published in the Civil Engineering Magazine of the South African Institution of Civil Engineering and is scheduled to present her research at Wits University’s School of Civil and Environmental Engineering.