Lihir Gold Mine, PNG - Newcrest Mining Ltd.

Failure of acid proof tiles leaves concrete and reinforcing mesh open to severe corrosive chemical attack.  Integral strength of concrete structure is reduced as a result, causing malfunction of processing operation.

Situation
Concrete neutralization system pits and chambers take a
through-put of 500,000 litres per hour, 24 hours a day. 
Tropical location, the effluent is never below 45°C.

Note the few remaining tiles in the corner of the pit some, which
have fallen to the floor. Note rusty lines showing where
the reinforcing rods used to be.

Concrete chamber with intake pipe

Extreme degradation of concrete is evident to walls and flooring
including the undermining of what is left of the acid proof tiles.

Surface preparation

Concrete walls cleaned and prepared to receive epoxy.
Note how much of the profile of a formerly straight wall
was lost. Epoxy floor installed 400mm thick.

Repairs

First stage of 3-stage formwork installation to walls & pipe inlet.

Formwork removed showing the restored walls using
epoxy grouting and over coating with Evercote 308.

Back in service

Fully restored concrete chamber pit.
Back in service after 8 days.