RecoveryBy Bento, Luis San Miguel
Posted on 2006-09-18 Last edited on 2010-12-10
Recovery is a section of Refining where syrups in excess from Affination and Crystallization are crystallized in successive boilings, normally in four boilings, untill a syrup is obtained from where it is not economically possible to extract more sucrose. This final syrup is named molasses.
Simplified scheme of Recovery
In this scheme it is presented three boilings (A, B, C) in the double-einwurf way. In the first boiling A massecuite is obtained by crystallizing affination syrup and 4th syrup. In this boiling a magma footing, A magma, prepared with B sugar and A syrup, is used to start the crystallization . A massecuite is centrifuged in batch or continual machines and the sugar obtained, A sugar or recovered sugar, is sent to the affination melter to be mixed with affined sugar, producing the affination liquor. The syrup resulting from A massecuite, A syrup, is crystallized in the second recovery boiling, producing B massecuite. This boiling uses a footing, B magma, prepared with C sugar and B syrup. From this massecuite, B sugar and B syrup are separated in continual centrifuges. B syrup is used to crystallize the C massecuite. This boiling is seeded using powder sugar slurry in ethanol or isopropanol. Before centrifugation, C massecuite is cooled to increase crystal size allowing the maximum possible sucrose extraction. After cooling, C massecuite is re-heated before centrifugation. Centrifugation is done in continual centrifuges and low purity syrup, molasses, is obtained. Sugar obtained in this centrifugation, C sugar is used to form the B magma.
Lyle, O., Recovery, in Technology for Sugar Refinery Workers, Ed. Chapman &
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