摘要 |
<p>A process is described for forming a body of whole untreated rice hulls by mixing with a heat setting binder. The mixture is formed into a generally desired formed shape of the body e.g. in a mould or die. The temperature throughout the formed shape is raised until a parameter indicative of or associated with the start of setting of the binder reaches a predetermined level or is observed. The setting of the binder is progressed beyond the start of setting, preferably under different process conditions, until the binder has substantially fully cured. To raise the temperature of the body, an RF field can be applied to cause dielectric heating within the mixture until condensing steam is seen emerging from the body, whereupon application of the RF field is stopped. Another heating process suitable for a porous body comprises creating a pressure differential through the mass and introducing a heated fluid so that the heated fluid passes through the porous mass. To make a denser body the porous mass that has just been heated can be compressed until setting of the binder has occurred yielding a stable shape having the increased density.</p> |