| 摘要 |
<p>Conversion of bleaching earth (I) to expanded porous ceramic granules (II) involves mixing (I) with organic material (III), which is carbonised at ca. 400-700 deg.C; pressing the mixt. to cakes; granulating these; and calcining the granules. Pref. (III) consists of cellulosic material, e.g. wood and wood fibres, or organic fuel, e.g. diesel oil. (I) is lean, scoured (I). (III) is added in an amt. of 0.1-25, pref. 0.5-15 wt.%. Fat (I) pref. is added to a cake of lean scoured (I), pref. in an amt. of 10-30, esp. 15-25 wt.%; and lime may also be added. The granules have a dia. of 1-50, pref. 4-25 mm. They are dried before calcination, pref. for 10-20 min. at 70-100 deg.C, then calcined 5-20 min. at 500-800 deg.C, pref. 8-15 min. 600-700 deg.C and then opt. sintered at 1000-1300, pref. 1000-1100 deg.C. Waste (I) from purificn. and bleaching of mineral and vegetable oils, fats and waxes can be converted to environmentally harmless, useful (II), rather than requiring disposal in special dumps. The process is esp. useful in conjunction with a process for scouring fat (I) by boiling, since the energy generated (esp. if fat (I) is used) at least partly covers the energy requirement of the boiling process.</p> |
