ABB Application Description - pH ORP Measurement. Sugar Mill Liming Process Application Note

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p H/ORP measurement Sugar mill liming process

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Sugar refining sugar mill liming process

Introduction To extract raw sugar juice, the mill first crushes, To create lime the mill heats limestone (calcium shreds, or presses the cane or beets. The raw juice is carbonate) in kilns to produce burnt lime (calcium highly pure, but contains undesirable organic and oxide) and carbon dioxide. The end product is mixed inorganic non-sugar constituents together with with water, becoming milk of lime (whitish lime color. The mill may add formalin or other particles suspended in water). The carbon dioxide antibacterial agents to the recycled press water. The introduced to the pre-carbonation tank mixes with addition of these chemicals work in conjunction water to become carbonic acid. with high temperature to inhibit bacterial growth.

Cane processors practice partial liming while beet

The next steps, pre-carbonation and liming, act to processors apply complete liming. The goal of purify the raw juice. During purification, insoluble complete liming is to reduce invert sugar (glucose solids, gums, polysaccharides and dissolved and fructose) as much as possible by adding an colorants coagulate out for removal by settling and excessive amount of lime. Cane processors partially filtration. Mills purify the juice using lime and destroy the invert sugars, using less lime. Some carbonic acid. refiners use a combined purification process

consisting of phosphoric acid and lime by which 30 to 37 % of the syrup color is removed.