Physicochemical properties of CaO-SiO2-CaF2-NaF slag system as a mold flux of continuous casting

被引：17

作者：

Nagata, K ^{[1
]}

Fukuyama, H ^{[1
]}

机构：

[1] Tokyo Inst Technol, Dept Chem & Mat Sci, Tokyo 152, Japan

来源：

STEEL RESEARCH INTERNATIONAL | 2003年 / 74卷 / 01期

关键词：

mould flux; phase diagram; fluorine; cuspidine; Gibbs energy; crystallization;

D O I：

10.1002/srin.200300158

中图分类号：

TF [冶金工业];

学科分类号：

0806 ;

摘要：

The phase diagrams of CaO-SiO2-CaF2 and CaO-SiO2-CaF2-NaF systems were determined as a base system of mold fluxes. The commercial fluxes have the composition in which cuspidine first crystallizes. The thermodynamic stability of cuspidine was examined from the standard Gibbs energy of formation of cuspidine, which was measured, by two methods of the Galvanic cell method and the transpiration method. The effect of fluorine to silicate network was investigated. It is indicated that CaF2 behaves as a neutral solvent for silicate slag. The crystallization in mold fluxes was measured by a high temperature XRD. Cuspidine predominantly appears because the construction of silicate glass with CaF2 has CaF+ ion pair near non-bridging oxygen. The over addition of Na2O to mold flux prevents cuspidine from crystallizing.

引用

页码：31 / +

页数：6

共 18 条

[1] THE SYSTEM CASIO3-CAF2
BAAK, T
OLANDER, A
[J]. ACTA CHEMICA SCANDINAVICA, 1955, 9 (08): : 1350 - 1354
[2] BILLS PM, 1963, J IRON STEEL I, V201, P133
[3] BRISI C, 1957, J AM CERAM SOC, V40, P174
[4] FUKUYAMA H, 2000, P 6 INT C MOLT SLAGS
[5] GUTT W, 1970, BRIT CERAM T, V69, P125
[6] Effect of fluorine on silicate network for CaO-CaF2-SiO2 and CaO-CaF2-SiO2-FeOx glasses
Hayashi, M
Nabeshima, N
Fukuyama, H
Nagata, K
[J]. ISIJ INTERNATIONAL, 2002, 42 (04) : 352 - 358
[7] PHASE DIAGRAM (64 PERCENT SIO2 + 36 PERCENT CAO)-CAF2
HILLERT, L
[J]. ACTA CHEMICA SCANDINAVICA, 1966, 20 (02): : 290 - &
[8] Hillert L., 1970, ACTA POLYTECH SCAND
[9] CRYOSCOPIC STUDIES WITH MOLTEN FLUORIDES .I. DEPRESSION OF FREEZING POINT OF CALCIUM FLUORIDE BY ALKALINE-EARTH FLUORIDES AND OXIDES AND CALCIUM SILICATES
KOJIMA, H
MASSON, CR
[J]. CANADIAN JOURNAL OF CHEMISTRY, 1969, 47 (22): : 4221 - &
[10] MILLS KC, 1988, IRONMAK STEELMAK, V15, P175

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