| 摘要 |
PURPOSE:To provide a calcareous crucible having a low apparent porosity by first producing slaked lime powder having specified average primary particle size and Ca(OH) content, and then firing the same at specified temperature. CONSTITUTION:Slaked lime powder is first produced which has the average primary particle size of less than 10mum and the Ca(OH) content of more than 98 weight %, and then is fire;d at 1,500-1,800 deg.C. The slaked lime powder is produced by hydrating lime which is obtained by firing highly pure calcium carbonate, and then is preferably press molded. The firing procedure is such that the preliminary heating up to 1,500 deg.C is conducted over a period of 20-45 hours to make the reaction moderate in which lime turns into slaked lime so that the resultant water may not damage the molded piece. This way, calcare ous cruicibles having the apparent porosity of less than 2% can be advantageous ly manufactured. |
