| 摘要 |
<p>PURPOSE:To provide thermal impact resistance, slag fusion loss resistance, etc. to a molten metal blowing lance pipe by winding fire resistant fiber impregnated with magnesia, alumina or the like and silica round the pipe outside and by further attaching a similar refractory. CONSTITUTION:A 0.5-15mm thick fire resistant fibrous substance is impregnated with an aq. silica sol contg. 40-90% of aggregate of magnesia, alumina or the like with a grain size of <=10 mesh (contg. 15wt% or mre of <=200 and 28-200 mesh) and 5-40% of solid matter as silica. This sol-impregnated substance is wound round a lance pipe to form the first layer. A refractory similar to the first layer is then attached to the layer to 0.2-3mm thickness as the second layer and dried by heating to form a 2-15mm thick fire resistant coating. Using the coated lance pipe a mixt. of oxygen, nitrogen, argon or other gas and a solid refining agent is blown into molten metal. Since this pipe is light-weight and is consumed at low speed, pipe exchange or addn. is made unnecessary in blowing, resulting in stable operation.</p> |
