| 摘要 |
<p>Prepn. of monoclinic BaO.Al2O3-2SiO2 involves (1) forming an intimate mixt. of powders of (a) 1 mole of BaCO3, (b) 8xy moles of AlF3, (c) 1-x moles of Al2O3, and (d) 8xy+2(1-x) moles of SiO2 for each mole of BaO.Al2O3.2SiO2 to be produced. In (d) x = 0.02-1.0 and y = 0.5-1. (2) forming topaz by heating mixt. produced in (1) to 700-900 deg.C in an atmos. of gases generated by the topaz formation; and then (3) heating mixt. produced in (2) in an atmos. of gases generated by the topax and BaO.Al2O3.2SiO2 formations at (a) 900-1590 deg.C, if x = 0.17-1.00, (b) 950-1590 deg.C, if x = 0.10-0.17 (c) 1000-1590 deg.C, if x = = 0.05-0.10 or (d) 1300-1590 deg.C, if x = 0.02-0.05 until monoclinic BaO.Al2O3.2SiO2 is produced.</p> |
