OVERVIEW: Critical minerals such as nickel are often processed in industrial environments where exposure to chemicals and by-products are far from conducive to corrosion prevention. Combatting the elements like acid rain and atmospheric corrosion can be detrimental to plant equipment, subsequently impacting productivity and operational costs.
INDUSTRY
ENVIRONMENT
Nickel Laterite mine operating at 100°C. Vessel is required to contain and hold Sulphuric Acid Slurry as part of the leaching process.
SUBSTRATE
Super Duplex Steel
CHALLENGE
The project required Chemcote to treat a super duplex steel vessel that held sulphuric acid slurry as part of the leaching process in a nickel laterite mine. Achieving adequate adhesion on super duplex steel at temperatures of 100°C was a key consideration.
The internals of the vessel had previously been coated with an epoxy that had failed within months of application, causing the substrate to corrode and pitting to occur. The externals required protection against acid rain and atmospheric corrosion, while also producing a durable hard-wearing finish.
SOLUTION
Following abrasive blasting with aluminium oxide to class Sa 2.5 90μm surface profile, several products were selected due to their adhesive properties and ability to create an impermeable barrier between the environment and substrate.
Chem-tect™ RC 364 was applied to a DFT of 400μm on both the internals and externals. The next step involved the application of Chem-tect™ RB 364CS to a total DFT of 1mm on the internals, then a final coat of Chem-tect™ RB 300TC to a total DFT of 400μm on the vessel exterior
SCOPE
Abrasive blast with Aluminium Oxide to class SA 2.5 90μm surface profile
Apply RC364 to a DFT of 400μm on internals and externals
Apply RB364CS to a total DFT of 1mm on internals
Apply RB300TC to the total DFT of 400μm externally
OUTCOME
A year after the new Chem-tect™ coatings were applied, the tank had remained in excellent condition. This reflects the high quality of the Chemco RB 300 product range in delivering a durable hard-wearing finish, but also effective corrosion protection against long-term acid exposure.
The client also requested the same treatment for other steel vessels within the site. Coating selection, approval, and application were performed by CCS, a distributor of Chemco International in Western Australia.
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