Brazil dam collapse reignites debate over storing mining waste
* 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. Continued...