Rankin and Wright — Ternary System CaO-Al,O z -SiO n . 45 



compounds whose compositions they connect, (b) others drawn 

 as dotted lines lie partially within these two fields, (c) still 

 others lie partially within only one of these two fields and (d) 

 one lies entirely without these two fields. 



(a) The straight line lies entirely within the fields of the 

 two compounds whose compositions it connects. As an exam- 

 ple of this, consider the line joining the compositions of the 

 two compounds OS (CaO.SiO.) and CAS, (CaO.Al 2 O s .2Si0 2 ). 

 This line intersects the ternary boundary 5-2 for CS and CAS, at 

 point M. That portion of the line connecting (7#and M is then 

 the melting curve of CS in solutions with CAS, and the por- 

 tion of the line connecting CAS, and M is the melting curve 

 of CAS, in solutions with CS. Point 3£ is the point at which 

 CS and CAS, melt together and is a eutectic point. The sys- 

 tem CS-CAS, is, therefore, a simple binary eutectic system 

 if one considers the compounds CS and CAS, as components. 

 There are eight of these binary systems represented by full 

 lines in fig. 12. Two of these systems, C^-C,AS and C,AS-CA, 

 occur on the same straight line and will be treated as a single 

 binary system in which there is one stable compound formed 

 C,AS. The data for the important points of these systems 

 are given in Tables XIII-XX, and the corresponding tempera- 

 ture-concentration diagrams are given in figs. 13-16. The 

 abscissa or concentration line for each of these systems is taken 

 directly from fig. 12 and ordinates were erected to represent 

 temperatures. 



Table XIII. 

 Melting temperatures of the binary system Si0 2 -CaO.Al 2 3 .2Si0 2 . 





Component 

 Si0 2 



Eutectic 





Component 

 CaO.Al 2 3 .2Si0 2 



CaO 



Composition a i r\ 

 Wt. per cent ^A 3 

 bi0 2 



o-o 



o-o 



ioo-o 



10-5 

 195 



70' 



19- 

 34-9 



46-1 



20-09 

 36*63 

 43-28 



Melting 

 temperature 



1625 



1359 



1542 



1550 



Table XIV. 

 Melting temperatures of the binary system CaOSi0 2 .-CaO.Al 2 3 .2Si0 2 . 







Component 

 CaO.Si0 2 





Eutectic 



Component 

 CaO.Al 2 3 .2SiO a 



Composition 

 Wt. per cent 



CaO 



A1A 



SiO, 



48-2 



o-o 



51-8 



41-4 



9-0 



49-6 



34-1 

 18-6 

 47-3 



27- 



27-5 



45*5 



20 9 

 36-63 

 43 28 



Melting 

 temperature 





1540 



1436 



1299 



1484 



1550 



