BlueScope Steelworks will begin a $1 billion rebuild of their No 6 blast furnace at their Port Kembla location, which will also include a new slag granulation plant.

The expected timeframe to complete all upgrades will take roughly 3 years.

Implementing several additional process and emission controls as part of the project, such as a slag handling condensing unit, will result in the reduction of emissions being expelled.

The slag granulation system is proposed to be fitted with a closed condensation tower in which cooled water will be used to condense the steam plume visible from the granulation stacks. From here, water will contact the steam arising directly from the granulation process, resulting in the steam falling back into the granulation bath.

The stove Waste Gas Heat Recovery system reclaims heat from the stove flue gases to preheat the air and fuel used for heating the stoves. The goal of this process is to decrease the amount of enrichment gas required for heating the stoves which will potentially lead to a reduction in sulphur emissions from the stove stack.

BlueScope are confident that this new slag granulating system will reduce emissions compared to their existing operations.

The proposed slag handling process will involve the transport of slag from the casthouse to the granulator in slag pots using a Kress carrier, which will then be poured into the granulation tower. It is believed that this process will reduce the H2S emissions based on previous data.

The slag handling area will also include hardstand surfaces graded to internal drains, allowing surface water to flow into the new slag pit settling pond or the granulator settling pond, and collected water from water sprays will be recycled as make up water to the granulator or as slag pit sprays.

BlueScope hope that maximising the use of co-products from steel manufacturing will offset and reduce emissions from their Port Kembla site.