| 摘要 |
<p>PROBLEM TO BE SOLVED: To produce an aritificial aggregate which is of high strength and low in water absorption irrespective of the difference of coal species, the difference of a style of coal burning boiler, the difference of melting point and a grain size due to a chemical composition of coal ash and the difference of the amount of remaining unburned carbon. SOLUTION: In the method for producing the artificial aggregate for concrete by mixing a caking agent, etc., into the coal ash, performing the granulation and sintering the granulated material, at first, artificial matrix synthesizing material 4 which contains the caking additive and becomes the geometrical base material when recrystallized is mixed into the coal ash 2 and the granulation is performed. The granulated material 8 is dried, thereafter, subjected to the calcining at a temperature of the order of 900-1,000 deg.C in a zone 15 of an oxidizing environment and, subsequently, subjected to the sintering at a temperature approximately up to about 1,250 deg.C in a zone 17 of reducing environment. The sintered material is slowly cooled and, thereby, the pellet-like artificial aggregate 23 in which the coal ash particles are encapsulated by the artificial matrix having a three-dimensional recrystallization structure of SiO2- CaO-FeO is provided.</p> |
