| 摘要 |
<p>The process, using slate quarry waste of any size to obtain a weather-resistant construction material for coating, decoration and roofing, consists of 3 milling stages, the final one in a cyclone which selects fractions of differing particle size. A phenoplast and plasticiser are mixed in water and the slate filter added. The mixt. is fed to a screw, soda added and extruded through a heated nozzle. The continuous sheet is cut at the nozzle outlet.</p> |
