| 摘要 |
PURPOSE:To impart cleaning action of steels and enable surface defects to be prevented by limiting the specific surface area of amorphous fluorine containing calcium silicate. CONSTITUTION:With the amorphous fluorine containing calcium silicate expressed by the formula 1 of Al2O3; 4% or under, P2O5; 1.5% or under and S; 0.4% or under based on weight; silicic acid containing material, calcium containing material and fluorine containing material are so prepared as to assume the abovementioned composition and the mixture is melted in a furnace. Next, it is water quenched and is ground with a mill. The powder is then classified so that the specific surface areas become a range of 2700+ or -500cm<2>/g. As the reason for restriction of the composition, CaO; of this range is preferable in terms of vitrification and dephosphorization, and with respect to F; the viscosity and surface tension suited for the additive is obtainable. |
