抄録
In recent years, because of the shortage in land disposal site, the waste burning at cement plant has become very important. And so-called chlorine bypass process is supposed to be the key technology. The main composition of the extracted dust in chlorine bypass is KCl. And the utilization or disposal of this dust is necessary to burn waste in a cement kiln.
In the previous paper, authors reported the influence of KCl on the alite hydration and on the hydrated products. But the total amount of chlorine in ordinary portland cement is limited at 200 ppm. in Japan Industrial Standard, in order to prevent the corrosion of reinforcing bars in concretes.
This paper deals with the hydration reaction of slag-KCl system which can contain larger amount of extracted dust. As a basic study to utilize lager amount of extracted dust in cementitious material, experiments were performed to know the phase composition change during the hydration of slag-KCl system in comparison with that of slag-Ca (OH) 2 system. The hydration products in slag-Ca (OH) 2 system were aluminum hydroxide gel and calcium silicate hydrate gel. And in slag-KCl system, Fridel's salt is formed in addition to the products in slag-Ca (OH) 2 system. The CaO/SiO2 ratio of calcium silicate hydrate gel produced in slag-KCl system were smaller value than that in slag-Ca (OH) 2 system, because of the CaO consumption to form Fridel's salt.
