Mechanism of Stabilization of Kaolin by Polymerization Technique

Abstract

This paper presents stabilization mechanism of Kaolin by Polymerization from 13 locations in
Thailand : 4 locations from Lampang, one location each from Uttaradit, Ranong, Suratthani,
Nanatiwat, Udornthani, Prachinburi, Rayong, Rachaburi and Phetchaburi. The polymerization was
carried out by mixing different substances such as Na2SiO3.5H2O, Na2CO3, Na2HPO4, Na3PO4, KOH
and NaOH with the specimens. Polymerization reaction was activated under a temperature of 80
degree celcius for 24 hours followed by cooling in room temperature. Tendency of stabilization was
studied using compressive strength tests of samples after curing for 56 days along with calorimetric
study to determine heat content during stabilization. Chemical elements, clay mineral, clay
mineral crytallization and cation exchange capacity were taken into account. Models were proposed
to describe the early polymerization mechanism of Kaolin for various maximum compressive
strengths based on heat evolution measurements. Most Kaolin samples such as Lampang Kaolin,
Phetchaburi Kaolin , Rayong Kaolin, Suratthani Kaolin, Ranong Kaolin, Naratiwat Kaolin,
Prachinburi Kaolin, and Udornthani Kaolin showed tendency of stabilization using KOH and NaOH
except Uttaradit Kaolin which can be stabilized by using Na2SiO3.5H2O.