Raw Sugar Affination
Affination is a traditional Refinery Process developed over a hundred years ago when the Raw Sugar had a much higher impurity level, that is a Pol of maybe 97 or 98. In these lower purity sugars, most of the impurities are located on the surface of the crystal. These can be removed by washing the surface of the crystal. If the crystal were washed with water, sugar would be dissolved so it is washed with a virtually saturated solution of sugar called Raw Syrup. A known weight of sugar is added to an appropriate quality of Raw Syrup and mixed in a horizontal mixer to remove the impurities from the surface of the crystal. The crystals are then separated in a centrifuge and the cleaned up sugar dissolved in the Melter. The impurities have been concentrated in Raw Syrup and this has to be separated into Molasses and recovered sugar in the Recovery Section, which would be the Factory Boilings in a Mill.
For a sugar in the region of 2,000 - 3,000 IU colour, then approximately 50% of the colour would be removed by affination. If the Raw Sugar colour is higher, then more impurities would be located on the surface of the crystal and so more colour would be removed, often giving a dissolved sugar of 1,200 to 1,500 IU colour.
Affination not only requires a large amount of heavy duty plant it also adds a significant extra requirement to Recovery/Factory and so the equipment in this area also increases significantly.
Affination is an ideal heavy duty process to be used for low Pol Raw Sugars. Affination can be considered as a process which converts a Low Pol Raw Sugar into a VHP Raw Sugar.
It is not appropriate for modern Refineries and Factories where higher purity Raw Sugar is available.
So we propose to use Higher purity Raw Sugar to get rid of this AFFINATION process.