| 摘要 |
<p>A process for manufacturing cement comprises the burning of a mixture of wood and grit aggregate in a fluid-bed furnace, wherein the grit aggregate disintegrates on burning. The grit aggregate comprises from 50 to 80wt% silica, 20 to 40wt% alumina, less than lOwt% calcium oxide and less than lOwt% magnesium oxide. When the grit aggregate disintegrates, it may yield oxidic species in a finely divided form. Preferably, the wood is selected from chipped virgin timber, waste wood, treated waste wood or a mixture thereof. A cement product is also claimed, which may be used as a replacement for Portland cement in ready-mix concrete, pre-cast concrete, mortar, grout, tile casting, reinforced concrete, high alumina cements, fast curing cements etc. Another independent claim is directed toward the use of a grit aggregate comprising 50 to 80wt% silica, 20 to 40wt% alumina, less than 10wt% calcium oxide and less than 10wt% magnesium oxide as a pyrolysis aid in a wood burning fluid-bed furnace.</p> |
