The Milling Process
Harvested sugar cane is transported to a raw sugar mill. Because sugar cane must be milled as soon as possible, mill owners have made substantial investments in cane railway networks and rolling stock. At the mill, sugar cane is weighed and processed before being transported to a shredder. The shredder breaks apart the cane and ruptures the juice cells. Rollers are used to separate sugar juice from the fibrous material, called bagasse.
The bagasse is recycled as a fuel for the mill boiler furnaces. Juice from the sugar cane is then subjected to a purification process before being concentrated by boiling in an evaporator. The concentrated juice or syrup is concentrated even further and is seeded with small sugar crystals in a process called crystallisation. The sugar crystals are grown to the required size by adding more syrup while the boiling continues.
Syrup is separated from the raw sugar crystals in centrifugals. Molasses is the syrup left over from the final centrifuging. The raw sugar from the centrifugals is then dried and transferred for short-term storage in bulk bins at the mills.
After milling, the raw sugar is transported to a bulk sugar terminal. From here, the sugar is either exported or transported to a sugar refiner like Sugar Australia.