Safe removal of acid sludge tanks

Environmental consultants Enviropacific were engaged when Nyrstar needed to safely remove two redundant acid storage tanks at its Tasmanian plant.

Nyrstar’s Lutana plant produces both zinc metal and pure sulfuric acid and the two steel tanks were designed to hold 1800 tonnes of acid each, stood 8 m high and were 10 m in diameter.

Enviropacific was tasked with neutralising and removing the residual sulfuric acid sludge that remained within the tanks and the tank surfaces also required cleaning before inspection and removal off-site. Enviropacific faced particular challenges as the tanks were located amongst several other tanks in active service and access to the tanks was limited by space and gradient restrictions. Additionally, a Hot Works zone overlay was present along with working-at-height and high-reach equipment permits on a daily basis.

Enviropacific reports that over 1000 man hours were carried out on the project, with no LTIs, medical incidents or environmental issues. None of the live equipment or serviceable tanks were affected and there was minimal impact, if any, on the day-to-day operations of the facility.