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Beets To Sugar — What’s Involved

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Lantic Sugar’s factory at Taber usually processes beets 24 hours per day, seven days a week from late September to April, running at a lower rate through the summer.

Processing beets starts with a flume that carries the beets in water over screens that remove rocks and trash into a washer. Beets are dried off and moved to the slicers, which cut beets into noodle-like pieces called cosettes. These are mixed with juice and carried by a rotating shaft to the top of the extraction tower where hot water is sprayed over them. Sugar diffuses into the hot water and this raw juice is moved from the bottom of the tower to be purified with some juice recycled to carry more cosettes to the top of the tower.

The exhausted cosettes contain only 0.5 per cent sugar compared to around 18.5 per cent when delivered. This pulp is moved to presses that lower its water content from 90 to 75 per cent. This water contains some sugar and is used in the extraction tower. The pulp can be fed wet, but most is dried with natural gas and pelleted.

Raw juice contains many dissolved impurities, which are removed by adding lime. The factory has its own lime kiln where limestone is burned with a controlled amount of natural gas to produce CO2 and calcium oxide. The calcium oxide (lime) is dissolved in water and added to the juice. It’s later removed in a two-step process.

The resulting thick juice, with 70 to 75 per cent solids, can be stored for later processing.

Remelted sugar is added to thick juice to make a standard liquor from which sugar is crystallized in white vacuum pans. These allow sugar to crystallize without heat, which could discolour the sugar. Sugar crystals remain suspended in syrup, so the mixture is dropped into a centrifugal, a basket spinning at high speed within a drum. After washing to remove traces of syrup, sparkling white sugar remains on the drum. The last one per cent moisture in the sugar is removed by warm air blowing through a rotating drum. It is then stored in silos, ready for packing and shipping.

At every stage of the process, washings and some of the processed material is returned to be recycled through the process, sometimes to keep things running well, other times to improve extraction rates. Syrup remaining in the centrifugal machines is crystallized in separate vacuum pans. The process takes several hours because of impurities, which make this sugar light yellow, so it is mixed with syrup and processed into beet molasses. This is mixed with beet pulp, sold as a feed supplement or used in yeast production.

Liquid sugar, sugar dissolved in water, is used by a variety of industrial customers. The Canadian market for crystal sugar and icing sugar is shared by Lantic Inc and Redpath, a Toronto company that processes only cane sugar. There is also some sugar imported from Guatemala and other countries.

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