| 摘要 |
<p>Combustible material is removed from rice husks leaving a residue of non-inflammable material consisting essentially of silica by drying the husks, exposing the dried husks in closed space to a uniform temperature not lower than 30 DEG C., moistering with water containing an enzyme, subjecting the moistened husks to a temperature of 40-45 DEG C. in a closed space until the temperature of the husks has increased by catalytic decomposition to a temperature not exceeding 67 DEG C, washing the solid residue and at least partially drying. The enzyme may be obtained by distilling dust obtained from rice, wheat or oats. Washing may be carried out at a temperature not lower than 20 DEG C. with lime water in a vat provided with agitators below a metal screen whereon the required product collects. The lime water treatment may be preceded by treatment with water. In some cases simple water washing is sufficient. Long-fibre plants of high silica content, e.g. equisetum palustre or equisetum arvense, may be added to the husks being treated. The product may be partially dried and mixed with solid glues or up to 20 per cent of wood chips or the like, or it may be dried, preferably with hot air until its moisture content is not more than 5-10 per cent and mixed with liquid or semi-liquid binders or glues, e.g. phenolic resins. The treated husks may be formed into sheets.</p> |
