| 摘要 |
PURPOSE:To prevent thermal decomposition and to obtain a dense sintered material in production of a sintered material of CaCO3 by sintering a powder raw material consisting essentially of CaCO3 under specifying sintering temperature and pressure of a high-pressure gas during sintering. CONSTITUTION:A powder raw material consisting essentially of CaCO3 such as coral sand is subjected to a pressed powder molding by cold work to give a molded article, which is burnt in a high-pressure gas atmosphere consisting essentially of an inert gas. In the operation, the burning temperature (t deg.C) is made in 900<=t<1,200 and pressure of the high-pressure gas (Pkgf/cm<2>) during burning is made in P>(6-600)<3.5>/4.7X10<8>. A sintered material having sufficient strength is not obtained when the burning temperature (t) is <900 deg.C and, on the other hand, CaCO3 is melted when the temperature is >=1,200 deg.C. Thermal decomposition of CaCO3 can be avoided by making the pressure P in the range. |
