MELBOURNE, Oct 11 (Reuters) – Sea disposal of mining waste could spread as Indonesia weighs adopting the technique for new nickel projects, as Papua New Guinea is doing for a gold mine proposed by Australia’s Newcrest Mining.
The management of mining waste has drawn attention since two dam disasters in Brazil, and after red mud spilled into Papua New Guinea’s Basamuk Bay from Ramu Nickel’s operations in August.
An expert in chemical contamination has called test results from the Ramu Nickel spill “alarming,” media said this week. That spill resulted from an operational failure, however, rather than an issue with tailings management.
Proponents say deep sea tailings placement, which pipes unwanted pulverised rock into the sea, is cheaper and less harmful, especially on tropical islands where earthquakes or heavy rain limit storage on land, near deep sea trenches. Critics say the impact of such marine disposal is poorly understood.
Fewer than 20 of the world’s 2,500 mines use the method to dispose of tailings waste, comprising rock, microscopic unwanted metals and traces of processing agents, such as cyanide.