130 



TABLE 125.— TRANSFORMATION AND MELTING TEMPERATURES OF LIME- 

 ALUMINA-SILICA COMPOUNDS AND EUTECTIC MIXTURES* 



Percent 



Transformation Temp. °C 



Melting t 1540±2 



a to p and reverse 1200±2 



Melting 2130±10 



7 to /3 and reverse 675 ±5 



(3 to a and reverse 1420±2 



Dissociation into Ca 2 SiO< and liquid.. 1475±5 



Dissociation into Ca 2 SiO« and CaO.. 1900±5 



Dissociation into CaO and liquid.... 1535±5 



Melting 1455±5 



Melting 1600±5 



Melting 1720±10 



Melting 1816±10 



Melting 1550±2 



Melting 1590±2 



Dissociation into Ca 2 Si04+Ca 2 Al 2 Si0 7 



and liquid 1335±5 



Eutectics 



Percent Melting 



Crystalline , * , temp. 



phases CaO Al a 3 Si0 2 °C 



CaAl 2 Si 2 8 



Ca 2 Al 2 SiO, )- 38. 20. 42. 1265 



Ca 2 SiC>4 



CaAUShOs 



Ca 2 Al 2 SiO, )- 29.2 39. 31.8 1380 



Al 2 Oa 



Ca 2 Si04 



CaAhO^ >■ 49.5 43.7 6.8 1335 



Ca 5 Al 6 0i4 



Ca 2 Al 2 Si07 



Ca 3 Si 2 7 



Ca 2 Si04 



Ca 2 Al 2 Si0 7 



Ca 2 Si0 4 



CaAUO* 



CaAl 2 Si 2 8 



Al 2 Oa 



Al 2 SiO 

 Ca 3 AlioUi8 

 Ca 2 Al 2 Si07 

 A1 2 3 



Quintuple points 



48.2 11.9 39.9 1335 



48.3 42. 9.7 1380 

 15.6 36.5 47.9 1512 

 31.2 44.5 24.3 1475 



Quadruple points 



3Ca0.2Si0 2 

 2CaO.Si0 2 



55.5 



44.5 1475 



* The majority of these determinations are by G. A. Rankin. 



t The accuracy of the melting points is S to 10 units. (Geophysical Laboratory.) 



SMITHSONIAN PHYSICAL TABLES 



