Rankin and Wright — Ternary System CaO-Alfi-SiO^. 37 



Table XI. 



Melting point of eutectic 2 for aCaSi0 3 + CaO.Al 2 3 .2Si0 2 + SiO, as determined 



from various compositions. 



Composition 



CaO 



A1 2 3 



25 

 5 



20 



10 



15 

 15 



30 

 5 



25 

 10 



20 

 15 



15 

 20 



35 

 5 



30 

 10 



Wt. 



per cent 



SiG 2 



70 



70 



70 



65 



65 



65 



65 



60 



60 



Temperature 



1171 



1183 



1174 



1165 



1175 



1173 1173 



1170 



1175 



1172 



1174 



1175 



1165 



1175 



1177 1175 



1171 



1169 



1169 



1183 



1175 



1165 



1174 



1173 



1170 



1173 







1174 



1165 





1169 





1172 







1174 











1171 







1173 













Mean 



1171 1180 1174 1165 1175 1175 1172 1170 1172 







Table XI (Continued). 











25 



20 



15 



40 



35 



25 



20 



23-5 



30 



35 



15 



20 



25 



5 



10 



20 



25 



145 



10 



10 



60 



60 



60 



55 



55 



55 



55 



62 



60 



65 



1172 1167 1168 1165 1171 1176 1173 1165 1165 1170 



1173 1171 1163 



1171 1172 1167 



1173 1167 



1166 



1174 

 1174 



1173 



1178 QuenchQuenchQuench 



1178 



1172 1171 1166 1165 1173 1175 1176 1165 1165 1170 



Point 1 is the 

 (CaO 9-8, A1 2 3 II 



Point 5 is the 

 2CaO.Al 2 O s .Si0 2 . 



Point 



eutectic for Al 2 Si0 5 , CaO.Al 2 O s .2Si0 2 and Si0 2 . 

 1345° 



■8, SiO. 



2 70-4); 1345° ± 5' 

 eutectic for CaO.Al 0.2SiO. 



CaSiO,, and 



(CaO 38, A1 2 3 20, Si0 2 42); 

 is the eutectic for 2CaO. Al 2 3 .Si() 2 , 

 2Si0 2 . (CaO 47-2, A1 2 3 11-8, Si0 2 41); 1310< 



Point 7 is the eutectic for AI 2 O s , 2CaO. Al 2 3 .Si0 2 and 

 CaO.ALO„.2SiO„. (CaO 29*2, Al.O. 39. SiO.. 31-8): 1380° ± 5°. 



1265° + 5°. 

 CaSiO, and 3*CaO. 



±5°. 



the 



(CaO 29-2, A1 2 3 39, SiO„ 31-8); 1380 



Point 12 is 

 and CaO.Al 2 3 . (CaO 37*5, A1 2 3 53-25, Si6 2 9-25); 1505° ±5 S '. 



Point 14 is the eutectic for Ca 2 Si0 4 , 5Ca0.3Al 2 3 and CaO. 

 A1 2 3 . (CaO 49-5, A1 2 3 43«7, Si0 2 6-8); 1335° ± 5°. 



Point 15 is the eutectic for Ca 2 Si0 4 , 5Ca0.3Al 2 3 and 3CaO. 

 A1 2 3 . (CaO 52, A1 2 3 41-2, Si0 2 6-8); 1335° ± 5°. 



The only satisfactory method for determining the melting 

 points of eutectics 14 and 15 is by quenching. Heating curves 

 to determine the temperatures of these two eutectics are unsat- 

 isfactory for the following reasons : (1) 5Ca0.3Al,0 3 , either 

 pure or in ternary mixtures, when finely powdered and heated 

 to a temperature at which melting begins, will boil up and con- 



