| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a magnesia-chrome refractory, capable of ensuring good strength characteristics, corrosion resistance and thermal spalling resistance by adding nickel chrome powder and chromium oxide powder in a specific ratio to a refractory composition containing a magnesia raw material and a chromia raw material as main components. SOLUTION: The magnesia raw material preferably contains MgO component in an amount of >=95%. The chromia raw material includes chromium ores. The nickel chrome powder has a particle diameter of <=100 μm, has a Cr content of 35-85 wt.%, and is added in an amount of 0.4-2.3 wt.% based on the refractory composition. The chromium oxide powder has a particle diameter of <=10 μm and a purity of >=95 wt.%, and is added in an amount of 2-10 wt.% based on the refractory composition. The refractory composition is kneaded, molded and subsequently dried to produce a non-calcined product. Therein, a preferable method for kneading the composition comprises, for example, adding a binder to the large coarse particles, coarse particles and middle particles of the magnesia raw material and the chromia raw material to coat the surfaces of the particles with the binder, and simultaneously adding magnesia raw material particles, chromium oxide powder, nickel chrome powder, etc., to the coated raw materials. |
