Ranger mine to restart processing after leach tank failure incident

Energy Resources of Australia’s Ranger uranium mine is close to restarting production after a leach tank rupture forced operations to cease at the site in December.

A leach tank at the site’s processing plant ruptured and collapsed, causing an acidic slurry spill.

The incident forced the shutdown of operations and a massive clean-up at the site, with the Federal Government announcing the mine will not be able to restart production operations without regulatory approval and the go ahead from a joint operation taskforce.

In a statement yesterday, the company said work to dismantle and remove Leach Tank 1 and its associated infrastructure from the processing area is complete.

ERA said the final clean-up of slurry material has also been completed and plans to get the processing plant prepared to restart will conclude this month.

The restart of processing operations remains subject to the receipt of regulatory approvals and will require the permission of Minister for Industry Ian Macfarlane and the Director of the Department of Mines and Energy in the Northern Territory, Victoria Jackson.

An internal investigation into the incident found the rubber lining inside Leach Tank 1, which is supposed to protect the tank from corrosion, had been damaged as a result of wear from a partially failed baffle inside the tank.

The company found the damaged rubber lining allowed the acidic slurry mixture to come into contact with the tank's steel wall, which ultimately led to the failure of the tank.

Seven critical actions were identified before any plant restart can occur including the replacement of baffles at all six leach tanks, tank inspections and thickness testing for all leach tanks and other processing plant tanks.

The report also recommended a further 28 actions to be undertaken on specific assets or systems before they are returned to service, which ERA has committed to implementing.

It said ongoing monitoring had confirmed the surrounding area had not been affected by the tank failure and containment systems worked to protect Kakadu National Park.

In a speech to shareholders’ at ERA’s annual general meeting yesterday, CEO Andrea Sutton said it had been a tough few months for the company.

"This has been a serious incident, but I would like to acknowledge the efforts of our employees in responding safely to the incident and ensuring no one was injured," Sutton said.

Meanwhile, ERA is forging ahead with plans to develop its Ranger 3 Deeps underground mine, and will submit the project’s environmental impact statement in the second half of this year.

The Ranger 3 deposit represents the miner’s long-term future, holding more than 34,000 tonnes of high grade ore, however mining the area is subject to approval from the government and traditional owners in the region.

The company spent $46 million exploring the Ranger 3 Deeps decline in 2013, with 40 holes completed in the December quarter totalling 8,383 metres.

It says exploration of the underground deposit remains on schedule and on-budget.

Sutton said the company recognised the “importance of restoring confidence in the safety and environmental performance of the Ranger mine”.


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