All my comments on the matter have been removed from the article. A couple of times. In any event, the process involves sugar centrifuges and boiling in vacuums (the vacuum lowers the boiling point of the sugar sludge so as not to burn the product). Pure sugar is naturally white and requires no bleaching. Per sugar.org:
Is sugar chemically altered or bleached during processing?
No, sugar is not chemically altered or bleached during processing. The sugar in your sugar bowl is the same as the sucrose naturally present in the original sugar beet and sugar cane plants, and is also identical to the sucrose in other fruits and vegetables.
Pure sugar crystals are naturally colorless. No artificial bleaching or whitening is necessary. Molasses, which is naturally present in sugar beet and sugar cane and gives brown sugar its color, is removed from the sugar crystal with water and centrifuging. Carbon filters absorb any remaining colored plant materials.