• About Sugar
• Products
• How Sugar is Made
  • In the Canefield
  • At the Sugar Mill
  • At the Sugar Refinery
• Types of Sugar
• Sugar and the Environment
  • Carbon Dioxide Gas Recovery
  • Chelsea and the Environment
  • Recovery of Good Carbon from Waste Water
  • Waste Management
  • Water Treatment
  • Energy Reduction Projects
  • Chelsea Heritage Estate
  • Chelsea Ponds
• Health and Wellbeing
• Common Questions About Sugar

At the Sugar Mill

Cane sugar is initially extracted in sugar mills in the areas where it is grown as soon as it is harvested. Sugar cane looks very similar to bamboo and has a very tough shiny outer coating which protects the sweet, woody juicy inner fibre.

How sugar cane is processed:

• The cane that is due to be cut in the field is burnt to remove all leaves. (Traditionally, the cane has been burnt before harvesting to remove leaves, weeds and other trash which impede harvesting and milling. However it is now common for sugarcane to be harvested green rather than burnt. Green harvesting allows the farmer to recycle nitrogen in the plant by leaving trash cuttings from harvesting in the field.)
• The cane is transported into a shredder where it is chops and shreds the cane into fibrous material.
• Pairs of rollers feed the cane through a series of mills. Each mill consists of three large rollers arranged in a triangular formation. This process separates the sugar juice from the fibrous material, called bagasse. The sugar juice is pumped away for processing into raw sugar and the bagasse is recycled. (bagasse is a great alternative to coal, and is used to fuel the boilers in the mill)
• The juice that is extracted through the mills still contains impurities, which are removed by adding milk of lime to the mixture and boiling it.
• The impurities settle out in large containers (clarifiers) and the clear sugar juice removed from the top of the clarifiers. The juice is concentrated by evaporating the water from it under vacuum.
• Concentrated juice (approx 65% sugar) is boiled under vacuum to form a thick syrup, in which crystals are formed.
• The crystals (raw sugar) and syrup (molasses) are separated in a centrifuge. The raw sugar crystals are grown to the required size by adding more syrup to the mixture while it is boiled under vacuum.
• The raw sugar is stored in large sheds ready to be sent to refineries all over the world.

continue to Refining Sugar...