| 摘要 |
<p>A powdered material with hydraulic binding properties has as principal component a fly ash obtd. by burning coal in a coal powder burning furnace using a burner feed of powdered coal intimately mixed with sufficient cpds. of Ca and/or Fe to make up any deficiency in these, so as to obtain a fly ash having a chemical compsn. in the range 50-70 wt.% CaO, 5-20 wt.% Al2O3, 15-30 wt.% AiO2 and 4-15 wt.% Fe2O3. Pref. the additives have a particle size at least as fine as that of the coal powder to which they are added. Pref. the mineral content of the coal is analysed continuously to allow the necessary adjustments to be made to the additive input.</p> |
