Optimization of the process of calcium-carbonate dispersion stabilization for paper industry needs

Abstract

This paper presents the optimized technological process for obtaining stable calcium carbonate dispersion (CaCO3) in accordance to the standard prescribed in the paper industry. The reason for using CaCO3 in paper production is their low price when compared to the cellulose fibers and its ability to improve the properties of the final product. However, CaCO3 is alkaline filler that has relatively poor chemical stability that may affect the characteristics of the paper. For this reasons it is necessary to optimize the technology for obtaining a stable dispersion of CaCO3 with particles diameter in range 1 mm <Dsr <2 mm, a pH of 9.7 and a viscosity of η<300 mPas. Diglycerintereftalate (DGTP) (dispersant - D1) and diethylene glycolterephthalate (DEGTP) (dispenser - D2) were synthesized from the waste poly(ethylene terephthalate) (PET) in addition to commercial - sodium tripolyphosphate (Na-TPP-D3) used in the grinding process. The pH stabilization was established with the addition of glycine/NaOH buffer, which allowed obtaining the dispersion with standard values of particle size, pH, viscosity and stability.

Keywords

• Calcium carbonate
• pearl-mill
• milling
• dispersion
• stability