In order to purify the beet raw juice, SMBSC produces the lime, for the manufacture of the calcium hydroxide slurry (milk of lime), and the carbon
dioxide gas - both needed for the carbonation process. These two chemicals are produced by calcining (burning) of limestone in vertical kilns, using
foundry coke as a fuel.
Sugar manufacturing quality limestone is greater than 95 percent calcium carbonate (CaCO 3) and foundry coke is over 95 percent pure carbon (C). The
products of their combustion are, therefore, calcium oxide (CaO) and carbon dioxide gas (CO 2). The carbon dioxide gas is passed through a scrubber
and then blown to and through the carbonation vessels under automatic alkalinity controlling regulators.
The calcium oxide, also known as quick lime, is hydrated in a slaker with sweet water from the carbonation sludge de-sweetening/drying filters. The
hydrated lime or calcium hydroxide (Ca(OH) 2) is slurried with excess sweet water to about 30 percent solids and is called milk of lime. This slurry
is pumped to the carbonation vessels in proportion to the raw juice flow.
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