52 Rankin and Wright — Ternary System OaO-Al 2 3 -SiO^ 



lines connecting the compositions of S (Si0 9 ), OS (CaO.Si0 2 ) 

 and OAS 2 (CaO.Al 3 8 .2SiO a ) as a separate and distinct ternary 

 system. This provides us with a ternary system in which the 

 three components unite to form no compounds either binary 



Fig. 17. 



CaO.S.0 2 



3Ca0.2S.0 2 - C 3 S 

 2CaO.Si0 2 -C 2 S, 



3CaO.Si0 2 - C3S 



AS-Al 2 3 .S.0 2 



3CaO.Al 2 3 



5M.3M 3 



CA C 3 A 5 



CaO.Al 2 3 3Ca0.5Al 2 3 



Fig. 17. Equilibrium diagram to show the course of crystallization when 

 ternary solutions of CaO, A1 2 3 , Si0 2 are cooled. 



or ternary. From fig. 17 it is obvious that the lines S-OS, 

 S-OAS^ and OS-OAS^ represent the three binary systems / 

 A, Z, and M representing the eutectics of the respective 

 binary systems, and that point 2 is the quintuple point. 



