| 摘要 |
<p>A slurry of ceramic raw materials, water and free-flow promoter, with a dry content of 65-72wt.% is made and then approx. 1 wt.% of foaming agent is added to it. The resultant foamed slurry is expelled from a pressurized vessel to the nozzle of a spray dryer such that the minimum frictional forces are exerted on it in the feed system. The resultant powder for pressing into porphyritic tiles is free flowing and cheaply and easily produced. Speckled (multi-coloured) tiles may be made by producing granules from a number of separate different coloured slurries, foamed and fed independently to separate spray nozzles in a common spray dryer.</p> |
