On the Porosimetry of Clinker

Abstract

The degree of burning of cement clinker is distinguished by its appearance, generally in most cement factories. Litre-weight (g/l) method is popular one to distinguish the degree of burning quantitatively, but it is very difficult, because its measurement differs by degree of charge into a measure for clinker and personal error is quite great, accordingly. Y. Kondo, Professor of Kyôto University, introduced (Proceedings of Japan Cement Engineering Association. III 1949) that E. W. Washburn and E. N. Bunting had measured rapidly the porosity of mortar and concrete by the porosimeter. We got a hint from the report, then measured the porosity of clinker and determined the degree of burning of it by this porosimeter. Besides, some relations between several factors in burning clinker were examined in detail as follows:
(1) Degree of sintering of clinker can be indicated by the porosity of clinker and the porosity is inversely proportional to the litre-weight.
(2) Under a certain condition, some corelations between hydraulic modulas, degree of burning, compressive strength of its cement mortar and free lime of which burned from rotary kilns are respectively indicated by some simple formulas and graphs.
(3) Microscopical investigations show that with increasing “porosity” the Alit increases in amount and size.
(4) Peculiarities of three kilns and personalities of its respective burners are examined.