MgO-”FeO”-SiO 2 FeO and MgO showing a solid soln

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MgO-”FeO”-SiO 2 FeO and MgO showing a solid soln Fig. 6.59. System MgO-”FeO”-SiO 2 including binary systems.

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MgO-”FeO”-SiO 2 FeO and MgO showing a solid soln. Fig. 6.59. System MgO-”FeO”-SiO 2 including binary systems. - PowerPoint PPT Presentation

Transcript of MgO-”FeO”-SiO 2 FeO and MgO showing a solid soln

Page 1: MgO-”FeO”-SiO 2  FeO and MgO showing  a  solid soln

• MgO-”FeO”-SiO2

FeO and MgO showing a solid soln

Fig. 6.59. System MgO-”FeO”-SiO2 including binary systems.

Page 2: MgO-”FeO”-SiO 2  FeO and MgO showing  a  solid soln

Fig. 6.57. System MgO-”FeO”-SiO2 (oxide phases in equilibrium with metallic iron) (after E. F. Osborn and A. Muan, Phase Equilibrium Diagrams of Oxide Systems. American Ceramic Society, Columbus, Ohio, 1960).

Page 3: MgO-”FeO”-SiO 2  FeO and MgO showing  a  solid soln

SiO2

MgO FeO

2900°C

L

2700°C

L

L+M

2000°C

Magnesiowustite

1870°C

1860°C

L+MM

solidsolubility

1800°C

Mag

nesi

owus

tite

+Fo

rste

rite

-Fay

alite(

Oliv

ine)

M+O M+L

O+L

Page 4: MgO-”FeO”-SiO 2  FeO and MgO showing  a  solid soln

P+L

O+P

M+O

O+L

X+L

1550°C

X+L

M+L

M+O

O+L

X+P

O+PP+L

1527°C

two pts meet at 1543°C

T+L

P+T

O+P

M+O

M+L

O+L

P+L

1450°C

T+P+L and O+P+L meet at 1305°C, and P+L disappears

pyroxene (P) is (MgO,FeO)SiO2

cristobalite (X) transformed to tridymite (T) at 1470oC

P L

T

O

T

P

O+L

T decrease

M+L

Page 5: MgO-”FeO”-SiO 2  FeO and MgO showing  a  solid soln
Page 6: MgO-”FeO”-SiO 2  FeO and MgO showing  a  solid soln

• the relation between the structure of a ternary diffusion couple and the phase diagram