Tailings dams technology – learning from failure (Part 2): Mines rethink safety measures

Author(s): 
Adriaan Meintjes interviewed by Mining Mirror
Date: 
Friday, February 15, 2019
First presented: 
Mining Mirror and www.miningmirror.co.za
Type: 
Article
Category: 
Geotechnical
Civil Engineering

In the past few years, there has been renewed interest in finding ways to make tailings storage facilities (TSFs) safer, following very significant failures at facilities like Mount Polley in Canada and Fundão in Brazil, writes Adriaan Meintjes.

This interest comes not a moment too soon, opening exciting opportunities for engineers and scientists to bring both experience and technology to the daunting task of evaluating and mitigating a wide range of potential risk factors inherent to TSFs and rock dumps.

Tailings dam safety has always been close to our hearts at SRK, as it was the failure of the TSF at Union Corporation’s Bafokeng mine in 1974 — the year that SRK was formed — that led to our involvement in designing under-drains for greater stability at Impala dams 3 and 4. These designs continue to function as planned more than 40 years later, and the future will continue to demand such innovations as the bar for TSF safety is constantly raised.

Evolution of tailings dams

To look back briefly on the evolution of tailings dam engineering in South Africa, dams were initially very small when mining first started in the 1870s, reflecting the limited scale of the mining itself. Essentially, the tailings disposal practice was uncontrolled, with tailings just pumped into rivers, streams, and lakes.

Sand dumps then developed, which were constructed in an almost dry manner. When process plants became bigger, however, the tailings process waste was transported in a tailing’s slurry, as plants increasingly used water as a medium in the extraction process.

Acknowledged: Mining Mirror and Miningmirror.co.za

 

SRK Africa