Calcium carbonate – polymorphism, origin in juice purification, sizes of aggregates, and their consequences, Krystalické modifikace uhličitanu vápenatého, Jeho vznik při epuraci, velikosti agregátů a jejich dopady na čištění šťáv
Sarka E.,Vladimir Pour VSCHT |
Bubnik Z.,Vladimir Pour VSCHT |
Kadlec P.,Vladimir Pour VSCHT |
Pour V.,Vladimir Pour VSCHT
Listy Cukrovarnicke a Reparske | Year: 2014
The formation of a polymorph in aqueous media is influenced by conditions of crystallization although once formed polymorphs of CaCO3 may transform to the most thermodynamically stable calcite. The article compares the shapes of crystals found in carbonation sludge with similar shapes obtained by precipitation of CaCO3 in the absence of sucrose.To identify the verious polymorphs from each other or from other crystalline substances, it is possible to use X-ray diffraction, thermogravimetry, infrared and Raman spectroscopies.The mechanism of calcium carbonate formation in the carbonation is described and it is discussed the influence of ionic strength on the supersaturation of the dissolved calcium carbonate is discussed. Specific surface area of carbonation sludge precipitate is characterized and the number of crystals of about 0.3 μm in an averaged settling particle is estimated.The final part of the article deals with influences on particle size of the carbonation sludge during juice purification, which are linked with the filtration and sedimentation rates of carbonation juices. © 2014, Listy Cukrovarnicke a Reparske. All rights reserved.