To withstand the high temperatures involved in the steel-making process, BlueScope's manufacturing equipment requires durable, hard-working thermal protection.
BlueScope's cooling pans undergo a regular protective coating regime to ensure they are protected from the extremely high temperatures.
The cooling pans are utilized in the sintering process, where the iron ore undergoes high temperatures, causing it to solidify into a mass. The hot sintered iron ore is cooled in the cooling pans using large fans before being fed into the blast furnace.
Six-monthly coating system
As recommended by Dulux® Protective Coatings Business Development Executive Adam Hockey, the cooling pans receive a six-monthly application of:
• First coat: Dulux® Hi Temp™ Uniprime @ 25-microns (µm)
• Second coat: Dulux® Hi Temp™ 600 @ 20-microns (µm)
• Third coat: Dulux® Hi Temp™ 600 @ 20-microns (µm)
The Hi Temp product range is specifically designed for high temperature applications and is often used for furnaces, boiler fronts, kilns, flues and exhaust systems.
Dulux Protective Coatings Technical Sales Representative, Jack Jaber explains that Hi Temp products are ideal for ongoing protection of the cooling pans.
"They are high-performing and straight-forward to apply which means they work well as part of a regular maintenance schedule," he says.
To ensure excellent results, the steel components of the cooling pans are coated offsite by Krop Industrial in Wollongong. The process involves blasting to remove the previous coating, followed by the application of the three-coat system using a spray application. Any necessary touch-ups are done on-site using brushes or rollers.
Heat resistant primer
Given the high temperatures experienced by the cooling pans, a primer with exceptional heat resistance is required.
Hi Temp Uniprime is a heat resistant silicone primer, that can withstand continuous service temperatures of up to 550°C.
"Its excellent heat quench resistance means it's perfectly suited to the extreme temperatures of the steel-making process," Jack says.
The primer comes with a catalyst, which facilitates air drying at ambient temperature if delays occur before topcoating.
High temperature topcoat
Hi Temp 600 was applied to the pans as the second and third coat. Like Hi Temp Uniprime, it is a silicone high temperature coating. It can resist temperature spikes up to 600°C and is suitable for continuous operating temperatures up to 500°C.
Jack explains that where heat curing is impractical, Dulux® Hi Temp™ Catalyst may be used to cure Hi Temp 600 at ambient temperatures.
"If the surface is to be handled before heating, Hi Temp Catalyst will increase coating hardness and improve resistance to handling damage," he says.
The steel protection used by steel specialists
Dulux Protective Coatings has partnered with BlueScope for several years, providing long term, sustainable protection for a range of equipment, infrastructure, and assets.
"For this project we were able to provide a practical, effective maintenance regime that is sustaining the service life of the cooling pans, minimising any downtime and lowering maintenance costs," Jack says.
Need high-performance thermal protection? Contact us today.
Image courtesy of BlueScope.
