STUDIES ON REFRACTORY CEMENTS AND MORTARS, IV

Abstract

Continuing the previous studies on refractory cementing materials (This Journal, 1936, 44, 441; 1937, 45, 219, 447), the present authors report in the present paper the results of further studies on various samples prepared in the laboratory under the special ideas. The brief summary is abstracted from the original Japanese communication, as following:(1) Further comparative tests of refractoriness by the ordinary method of Seger's cone and the corrosion test by addings several samples of slags, ashes, glasses, etc., were applied to the prepared samples in the former report III (loc. cit.) and the results were compared and discussed with those of common refractory cements from the market, which were already reported in the former reports I and II (loc. cit.).(2) Two series of samples of hydraulic refractory cements (Series III: No. 7-No. 9 and Series IV: No. 10 and No. 11) were prepared under the same principle adopted in the preparation of the special hydraulic refractory cements Series I and II in the former report III, i.e., by mixing the first refractory element of high alumina content and high refractoriness and the second hydraulic element of high alumina content and strong hydraulic property in the proportions 70-90: 10-30. These samples were again exactly tested on their various important points as hydraulic refractory cement and compared to those of Series I and II and commercial samples in the former Reports:(3) Further, the preparation of special hydraulic refractory cements were carried out, i.e., (a) Series V: No. 12-No. 13 and Series VI: No. 14-No. 16, by the proper mixing the first refractoty element of high alumina content and the second hydraulic element of also high alumina content with the third special element confering plasticity on the mixture, e.g., bentonite, and (b) Series VIII: No. 17-No. 20, by mixing as the second element 3CaO⋅5Al2O3(C3A5) of synthesized compound of highest alumina content and as the third element slaked lime Ca(OH)2 of very fine powder. These samples were fully tested on their important properties as hydraulic refractory materials and brought the good results certifying as the superior refractory cements.(4) The authors are now specially studying on the application of these special hydraulic refractory cements for other purposes, which will be reported hereafter in another paper (“Studies on Hydraulic Refractory Cements', Journal of Soc. Chem. Ind., Japan, 1937, 44, 422 and its Supplemental Binding, 197B).