Everything you need to know about recycling fly ash
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Learn more about recycling fly ash
How to recycle fly ash
When coal is burnt, two types of ash are produced. The fine ash recovered from the flue gas is called fly ash. Particles that fuse together and fall to the bottom of the furnace is called bottom ash. While there are many potential uses for fly ash, there are currently limited recycling options available. In 2018, the Ash Development Association of Australia reported that about 33% of fine-grade fly ash was used in high-value applications such as cementitious binders and concrete production.
Some commercial waste management services will accept fly ash for recycling. Use the directory on this page to find a recycler near you.
Why recycle?
Fly ash can be used as a partial replacement for the sand, limestone and cement content in concrete. By reducing the need for cement production (a highly energy-intensive process), the reuse of fly ash leads to reductions in greenhouse gas emissions of almost 1 tonne of carbon dioxide per tonne of cement. Fly ash also enhances the performance of concrete in regard to workability, shrinkage and durability.
What happens to it?
In Australia, the majority of fly ash produced is suitable for cement production, because it reacts with lime in the presence of water to form a type of cement. The coarser furnace bottom ash is used as a sand replacement, aggregate for lightweight blocks, a road-base component, for agricultural drainage mediums and bulk fill.
