Customer Newcrest Mining
Sector Mining
Products
- Fosroc Nitomortar 903
- Fosroc Nitomortar F4 Fillers
- Fosroc Nitocote EP410
- Fosroc Nitoprime Zincrich
- Fosroc Renderoc LA55
- Vector Galvashield XP4 Anodes
In Western Australia's Pilbara region, Newcrest Mining operates one of the largest gold mines in Australia.
Fosroc ANZ's specification team visited the mine site in Telfer to provide a solution for bund remediation works using many Fosroc products.
Gold elution process takes its toll on concrete and steel
Dennis Murray, Fosroc's Account Manager for Greater Perth, explains the impacts of chemical exposure.
"Solid sodium hydroxide is used in the gold elution process. Chemical attack from the acid meant 70% of the bund floor area needed to be removed, reinstated and protected," Dennis explains.
The acid sump also needed to be broken back to sound concrete and reinstated. Several plinths and steel reinforcements were damaged beyond repair.
Concrete eroded due to long term acid exposure
Multi-step remediation and protection
Fosroc's specification delivered a comprehensive repair with multiple layers of long-term protection built in, for both steel and concrete. Renderoc LA55 and Nitocote EP410 were key products.
Extensive surface preparation was required, including the removal of damaged concrete and any old membranes and polyurethanes.
"New key ways were cut to enable the repair mortar to bond to the existing floor. After a high pressure wash, the applicators could start the repair," says Dennis.
Fosroc products were applied in the following steps:
Step 1: Floor screed installed using Nitomortar 903 with Nitomortar F4 Fillers. This created a high strength epoxy mortar that hardened quickly.
Step 2: An extra coating of Nitomortar 903 was applied to seal the screed.
Step 3: For excellent resistance against aggressive chemicals, two coats of Nitocote EP410 were applied to the bund floor, bund sump and up stands.
Step 4: All new steel was coated with Nitoprime Zincrich. For steel that was able to be retained, an abrasive blast achieved Australian Standard Class 2.5.
Step 5: Vector Galvashield XP4 anodes were connected to the steel-reinforced plinths.
Step 6: The plinths were formed, pre-soaked and poured with Renderoc LA55.
Step 7: The bund sump walls were broken back to host concrete in good condition, then formed and poured with Renderoc LA55.
Floors reinstated using Nitomortar 903 with Nitomortar F4 Fillers
Bund coated with Nitocote EP410 and plinths being poured using Renderoc LA55
Renderoc LA55 reinstates plinths and sump walls
"Renderoc LA55 is an industry-leading reinstatement mortar that offers diverse benefits. High strength and free flowing, it can be pumped or poured into virtually any location," Dennis explains. "It is often used with our Vector Galvashield anode protection systems, so both steel and concrete have superior protection."
The benefits of Renderoc LA55 for this project included:
- deep section repair up to 200mm
- exceptional flow into restricted locations
- maximum compatibility with concrete compressive strength, 30-60 MPa
- unique dual expansion system offers an extremely high level of control of plastic and long-term drying shrinkage
- complies with EN1504-3 Class R4
- low alkali content minimises risk of alkali-silica reaction
- excellent bond to concrete substrates without independent primer
- very low permeability protects against carbon dioxide and chlorides
- self-compacting nature eliminates honeycombing and displaces air without vibration.
Nitocote EP410 protects mine surfaces
This high build two pack epoxy coating is ideal for mines and other environments with aggressive chemical exposure and immersion conditions. Benefits for this project included:
- excellent chemical resistance
- excellent adhesion and film build to SSD concrete and steel
- excellent abrasion resistance
- easy application.
Find out more
- Download our Concrete Repair Solutions brochure
- Read about Fosroc ANZ's commitment to independent product testing
- Scroll down to complete our enquiry form. Our expert team will be in touch to provide a tailored specification.
