Cooling crystallization of raw juice

For some years, the problem of the elimination of the calco-carbonic purification process has been studied by using alternative technologies. Some of them, firstly studied in the laboratory and then in pilot plants, are based on the direct concentration, under reduced pressure and countercurrently, of the raw juice, which is then crystallized by cooling. The raw sugar obtained needs to be refined in order to be turned into commercial white sugar and such a process is based on steps of solution, filtration and recrystallization.

In this paper the possible application of cooling crystallization as a method of beet or cane sugar purification is discussed. The cooling crystallization experiments made both under laboratory conditions and on a pilot plant are reviewed. The authors conclude by presenting a picture of the situation as regards adopting the cooling crystallization technique by taking into account the possibility of utilizing plants which do not automatically require high investment costs. The results of laboratory tests carried out on microfiltered syrups are presented and discussed.