Brazil dam collapse reignites debate over storing mining waste

miércoles 18 de noviembre de 2015 17:00 GYT

* Disposing of ore waste big global safety, environmental issue

* Alternative engineering known as "dry stack" often put forward

* Cost, climate can make alternatives costly, unviable

By James Regan and Susan Taylor

SYDNEY/TORONTO, Nov 19 (Reuters) - A deadly mud slide at an iron ore mine in Brazil has reignited calls for safer ways to dispose of millions of tonnes of ore waste held back by man-made dams.

The disaster at the Samarco iron ore mine is only the latest in a series involving tailings - waste in mining parlance - that have devastated the environment, and in the case of Samarco, killed at least 11 people and left another 12 missing.

Tailings are typically a mud-like material and their storage and handling has become a major safety and environmental issue, since they can be toxic and may need to be kept isolated.

The Nov. 5 disaster has been termed an "environmental catastrophe" by Brazil after sending waste across two states and liability could fall on Samarco's joint owners Vale and BHP Billiton .

BHP Billiton's chief executive said the miner was reviewing all of its dam facilities and that the companies involved in Samarco would set up an inquiry with submissions from a wide range of experts, including on the history of tailing dams.   Continuación...