Continuous Improvement – Shutdown maintenance program

Pictured above: Maintenance teams at Laverton Rolling Mill and Sydney Bar Mill who were hard at work during the new year period.

Teams at our steel mills seized the opportunity of plant access during closures over the new year period – completing major renewal and maintenance projects to ensure the future health and sustainability of our equipment and eliminating end-of-life risks.

Here we outline some of the larger projects of asset renewals which were completed alongside large scopes of routine preventative maintenance and asset strategy tasks.

Laverton Melt Shop

The first major project was replacing the caster ladle and tundish turret bearings following years of service and wear. This was a complex change-out that needed extensive pre-planning and involved the design and manufacture of special lifting jigs and cradles to lift the main components into place. This ensured safe and precise handling and setting down of equipment.

The next project focused on replacing the scrap runway – a concrete structure supporting the rails on which the scrap cars move along. A 50m section of the runway was dug up so new foundations could be poured, and new rails installed. Replacing the runway used 600 cubic metres of concrete and 200m of track.

Another project involved replacing the platform in front of the electric arc furnace (EAF) – the heart of our steelmaking. The concrete panels making up the floor were demolished by heat stressing and cracking them. New concrete panels were pre-cast on site before being installed along with concrete side infills and new steel floor sheets.

Laverton Rolling Mill

Our bar mill received quite a bit of attention during the maintenance program. The reheat furnace was relined to ensure reliable operations over the coming years.  The Pusher hearth was replaced, along with some other refractory repairs, and the peel bar and discharge doors were completely rebuilt using a new pre-cast block design.

The reheat furnace control system was also upgraded with a modern and updated system designed to ensure reliability. The bar mill scale pit was fully cleaned and repaired, with a new concrete base cast and cracks filled to address deterioration identified by our integrity audit process.

The frame for the peel bar was also replaced after 10 years of service. The new frame is an updated design to improve the reliability and servicing of the equipment and reduce wear on the furnace hearth.

Sydney Bar Mill

The bar mill uses an in-line Zumbach gauge to measure the profile of our steel products – this essential process control tool had reached the end of its life, and a new one was purchased. Close collaboration from across our Maintenance, Operations and Technical teams successfully designed, installed, and commissioned the new gauge. This was despite the engineer from the European equipment supplier being unable to attend due to border closures.

In another critical project, 40m of underground pipe between the water treatment plant and the mill was successfully replaced. The pipeline carries process water between the mill and the water treatment plant.

The teams were also kept busy on several other key maintenance projects, including the refurbishment and alignment of the shear 3 gearbox, upgrades to the air circuit breaker and variable speed drives, and repairs to the reheat furnace bellows

Sydney Melt Shop

Aside from replacing the main TX1 transformer, several other asset renewal projects were completed.

The billet caster intermediate roller table was replaced after many years of service.  The area was thoroughly surveyed before new structural beams and floor gratings were installed to provide a solid base for the table. The team worked closely with others who were also in the area overhauling withdrawal and straightening units.

This was an important project for future proofing the area which will see the installation of billet push down rolls planned for 2022. The rolls will improve safety by reducing the need for manual handling of billets in the caster run-out area.

During the same shutdown, part of the electric arc furnace de-dusting circuit was undergoing critical repairs. The underground concrete duct, which conveys EAF off-gas to the fume treatment baghouse, is affected over time by the high natural water table in the area and needed an overhaul.

Other maintenance projects completed during the shutdown included replacing the ladle car track and wheel to reduce the risk of derailment and replacing the interior fill material and refurbishing the external structure of the caster cooling water tower.

These projects, and the many more that were completed, are an investment in the future of our core assets and will ensure that our world-class performance continues. The work couldn’t have been possible without the sacrifice and contributions of our hard-working maintenance and operations crews over the festive period.

The work completed will continue to support the asset reliability and quality performance at our Manufacturing facilities, as InfraBuild keeps investing in the long-term health of our assets.