A process water tank, at the Iluka Minerals site in Geraldton, Western Australia, that was constructed in the early 1970’s had become unserviceable due to corrosion around the base. The tank is 25 metres wide and 3 metres high, was constructed with steel-walls and a concrete foundation. It has a capacity of approximately 1.4 million litres.
Faced with the prospect of a $1.2 million replacement cost, Consulting Engineer John Montgomery in association with engineers from Illuka Minerals developed a strategy for the rehabilitation of the tank at an economically viable cost.
It was determined that the most appropriate remediation system was to employ Xypex Admix C-5000 in a shotcrete mix and incorporating Kuniseal C-31DS waterstop positioned in the floor wall joints.
As a result approximately 45m3 of Xypex Admix C-5000 dosed shotcrete was sprayed up against the existing metal walls, and approximately 100 lineal metres of Kuniseal C-31 DS was installed.
This system enabled an estimated saving of approximately $900,000 and significantly a reduced down time of only 14 days.
On completion of the repairs, the tank was filled and while initially there were a number of minor leaks, these reduced to zero within 10-14 days, as the Xypex crystalline development took place. The structure is again in service and remains watertight and now has a greatly extended service life expectation.