Traditionally, sugarcane processing requires two stages. Mills extract juice from freshly harvested cane to crystalise it into grains that becomes sugar, and sometimes whiten it to make "mill white" sugar for local consumption. Sugar refineries, often located nearer to consumers in North America, Europe, and Japan, then produce refined white sugar, which is 99 percent sucrose. These two stages are slowly merging. Increasing affluence in the sugar-producing tropics increased demand for refined sugar products, driving a trend toward combined milling and refining.
Old wood sugarcane press in Goiás, Brazil
japanese 19th wood sugarcane press in Tokunoshima
Small rail networks and trucks are common methods of transporting cane to a mill. Newly arrived cane is tested for sugar content and trash percentage.
The mill washes, chops, and uses revolving knives to shred the cane. ...view middle of the document...
Bagasse makes a sugar mill more than energy self-sufficient; surplus bagasse goes in animal feed, in paper manufacture, or to generate electricity for sale.
Continuous sugar centrifugal for recovery products
The cane juice is next mixed with lime to adjust its pH to 7. This mixing arrests sucrose's decay into glucose and fructose, and precipitates some impurities. The mixture then sits, allowing the lime and other suspended solids to settle. The clarified juice is concentrated in a multiple-effect evaporator to make a syrup of about 60 percent sucrose by weight. This syrup is further concentrated under vacuum until it becomes supersaturated, and then seeded with fine sugar crystals. A batch type sugar centrifuge separates the sugar crystals from the mother liquor. These centrifugals have a capacity of up to 2,200 kg per cycle.  The sugar from the centrifuges is dried and cooled and then stored in a silo or directly packed into bags for shipment.
The mother liquor from the first crystallization step (A-product) is again crystallized in vacuum pans and then passed through continuous sugar centrifugals. The mother-liquor is again crystallized in vacuum pans. Due to the low purity the evapo-crystallization alone is not sufficient to exhaust molasses, and so the so-called massecuite (French for “boiled mass”) is passed through cooling crystallizers until a temperature of approx. 45 °C is reached. Then the massecuite is re-heated in order to reduce its viscosity and then purged in the C-produced centrifugals. The run-off from the C-centrifugals is called molasses.
The spun-off sugar from the B-product and C-product centrifugals is re-melted, filtered and added to the syrup coming from the evaporator station.
Raw sugar is yellow to brown. Bubbling sulfur dioxide through the cane juice before evaporation changes many color-forming impurities into colorless ones. This sulfitation produces sugar known as "mill white", "plantation white", and "crystal sugar". Such sugar is the most commonly consumed in sugarcane-producing countries.