| 摘要 |
PROBLEM TO BE SOLVED: To obtain fine magnesia powder with a specific particle size, coated with a slaking-suppressive agent, excellent in slaking proofness good in fluidity when kneaded, and to obtain a prepared unshaped refractory improved slaking- proofness and fluidity by compounding the above magnesia powder. SOLUTION: This slaking-proof fine magnesia powder <=20μm in average particle size is obtained by coating itself with a slaking-suppressive agent for slaking proofness treatment. The slaking-suppressive agent is prepared by mixing a basic organic acid multivalent metal salt (except alkaline earth metal salt) with an organic acid followed by drying. The amount of the slaking-suppressive agent to be added is 0.1-15wt.% or so based on the amount of the fine magnesia powder. To coat the fine magnesia powder with the slaking-suppressive agent, both of then may be mixed with each other in a mixer, or the fine magnesia powder may be ground to an average particle size of <=20μm in the presence of the slaking-suppressive agent. |
