Activities of Fe t O in CaO-Al 2 O 3 -SiO 2 -Fe t O (<5 pct) slags saturated with liquid iron

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9

ULOO

T

-

9

9 [] m 0.5

9

I

I I llllf

-

I

]0 eq.

5

ACS -2 ACS-4 ACS-5

zx O O

I

I IIIII

I

I~

ss. FeO A &

I llili

I

0.1 , 0.0001

@

I

I I IIlll

I

I IIIlll

I

I

I Illlll

0.01

0.001

0.1

A

9

2

l

ss. FeO 0 [] []

XFetO

T

~--

0.2

1873K

eq. O rq V D

CAS-5 CAS-8 CAS-9 CAS-10

Fig. 7 - - Activity coefficients of Fe,O(1) in CaO-AI203-SiO2 slags saturated with a CaO crucible.

& 2

SiO2

&

Fo,o

,or

,,

,\

40

60

\60

O @ @

1

0.5 0,0001

i

i

i I li|I]

i

J IJitll

0.001

I

0.01

I

J IlllJl

0.

XFetO Fig. 6--Activity coefficients of Fe,O(I) in CaO-AI203-SiO2 slags satarated with an A1203 crucible. VlETALLURGICALAND MATERIALSTRANSACTIONSB

CaO

9_0

80

(mass-%)

AI20 3

Fig. 8--Activity coefficients of Fe,O(1) plotted in CaO-Al203-SiO2 phase diagram. VOLUME 25B, DECEMBER 1994--899

-

I

I I IIIIl[

I

I I IIII1[

I

1873K

10

I

I IIIll

A

I

I

I

I IIIII

I

I

I II111

10

AA

I

1

I

I IIIIII

I

I

I IIIll

I

1873K

z~x

I

--1 - ^

'~

A ,,,~ 10

[]

0.1

10

9 O

t/.

-v- v--~[- ~

0.01

2:>'-

[][]rl []

I

9

i

I

0

T

1

I I Illtl[

0.0001

1

I I Illll[

I

0.001

AC

[]

A

CA

nl

V

I I Illlll

l

ACS-2 ACS-4 ACS-5

0.01 L

I I Illll

0.01

I

I

eq. FeO A A 0 9 0 I I Illll

0.0001

0.1

I

I

AI + 3/4SIO2 (s) = 3/4S_j + 1/2A1203 (s) J/mol [~~

(3/4) log as_i + log

1/2

i IIIlll

0.1

3/4

-~.

I IIItl

I

I

I

I Illll

I

I

t

IIItll

I

I

Oo

1

9

[] 10

0.1 [] 17

H

rn

1>

U

: CAS-5 CAS-8 CAS-9 CAS-IO

[10]

The activities of A1 are plotted against those of Si in logarithmic form in Figure 14 for the ACS slags in equilibrium, supersaturation, and FeO-slag experiments. The same relationships for the CAS slags are shown in Figure 15. In this case, the a m and a m values were evaluated by using the respective interaction parameters, except for those related to oxygen. It is apparent that all the data points fall on the same line with a slope of 3/4, as predicted from Eq. [10], irrespective of the experimental methods, except for a few data points marked by asterisks in the equilibrium ACS-2 experiments TM in Figure 14. This finding indicates that Reaction [9] is not influenced by the oxygen content in the bulk metal phase. The values of aAj2o~with respect to the solid standard state can be estimated from an intercept in a plot of log a m v s log asi by using the asio2 values of Rein and Chipman 16) and the respective interaction parameters tm for f~a and fs~ given in Table IV. These results, which are summarized in Table III, are plotted in Figure 16, 900--VOLUME 25B, DECEMBER 1994

I

0

[9]

{(aAhO3)/(g9"~,s~o~,

I

10 _ 7_

The following relation is obtained by using the equilibrium constant K9 for Reaction [9]: ~.

I

0.01

Fig. 1 0 - - A c t i v i t y coefficients o f Fe,O(1) in CaO-AI203-SiO2 slags saturated with an AI203 crucible calculated from Reaction [5].

I

by solid circles in Figure 13 fall well on the lines for the results calculated from Eq. [8]. The error bars represent the standard deviation. The present results summarized in T