| 摘要 |
<p>PURPOSE:To utilize coal ash which is an unnecessary component and obtain a hydraulic product such as cement by reacting fine CaO or CaCO3 particles with vaporized SiO2 at a high temperature provided by burning the coal ash and collecting the resultant product. CONSTITUTION:Coal, an oxidizing agent and coal ash (10a) and (10b) are burned in an oxygen-enriched combustor 8 to provide a temperature as high as about >=2300 deg.C. SiO2 contained in the coal ash is vaporized. CaO or CaCO3 (13a) and (13b), having about <=10mum particle diameter and introduced thereinto is reacted with the vaporized SiO2 12 to afford alite 3CaO.SiO2 14, which is then cooled and solidified with a cooling gas (15a) and (15b) to provide cement 16. The resultant cement 16 is recovered with a bag filter, etc. Slag 17 dropped from a downward slag tap part 4 is quenched with a water tank and converted into amorphous granulated slag, pulverized and used as a concrete admixture. The aforementioned method for production has the following effects. Low cost of raw material unit is obtained and the slag is also used as the concrete admixture and can effectively be utilized. The silica mixing ratio can be regulated, etc.</p> |
