Investigation of particle size distribution of carbonatation precipitates in beet sugar manufacture

Analysis of the particle size distribution (PSD) of suspended particles in carbonatation slurries is important for assessing the efficiency of the juice purification in beet sugar manufacture. Breakthrough of fine particles into filtered juices reduces the quality and yield of sugar. The particle size distribution of carbonatation precipitates was studied before and after separation using different filter types and cloths under the technical conditions of eleven sugar factories in Ukraine. Turbidity of the clarified juices was also measured. In some cases, the same average size of solid particles was found before and after filtration. This was caused by a breakthrough of fine particles of the formed sediment layer through the filter cloth, aggregation on the back side of the filter, and subsequent ingress into the filtrate. It was further shown that it was possible to increase the size of the particles of the second carbonatation juice using a small amount of sodium carbonate. Multifilament filter cloths had a higher efficiency for the separation of carbonatation precipitation compared to monofilament filter cloths. Approximate ranges of particle sizes for carbonatation slurries in sugar production are shown.