The Crystallisation of Calcium Molybdate and Tungstate from Lithium Chloride Melts by Continuous Cooling. The Kinetics of Crystal Growth in Alumina Crucibles

✍ Scribed by Dr. A. Packter; B. N. Roy

• Publisher: John Wiley and Sons
• Year: 1974
• Tongue: English
• Weight: 402 KB
• Volume: 9
• Category: Article
• ISSN: 0232-1300
• DOI: 10.1002/crat.19740091205

✦ Synopsis

Abstract

The kinetics of crystallisation of calcium molybdate and tungstate from unstirred supersaturated solutions in lithium chloride melts — in alumina crucibles — was studied by continuous cooling from initial temperature T~0~ = 800°C down to room temperature at cooling rates R~T~ = 20° to 200°C hr^−1^. The solutions were analysed chemically and the crystals were examined by optical microscopy. Crystal growth started practically immediately after the onset of cooling: at first, the amount of material deposited onto crystals was far less than the amount of excess solute developed within the supersaturated solutions but crystallisation rates then increased as the crystal sizes increased. Then, after some time t* (at about seventy percent crystallisation), all excess solute was deposited onto growing crystals.