| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain an artificial lightweight aggregate, as the problems on the reduction and recycle of industrial waste are solved by using three kinds of industrial waste, namely concrete sludge, waste molding sand and soil occurring in water purification plants as major materials and firing them together with a foaming agent. SOLUTION: Concrete sludge, waste molding sand and soil occurring in water purification plates are mixed in a weight ratio of 1.0: (1.0-2.5):0.1-1.0 on the dry basis and silicon carbide is admixed, as a foaming agent, in an amount of 0.1-0.2wt.%. The mixture is molded in sheets, dried, and mold-granulated into macadam in indeterminate form. The mold-granulated product is heated near 1,000 deg.C to effect foaming and fired at 1,100-1,300 deg.C to produce the objective artificial lightweight aggregate in a macadam form. As for foaming in this aggregate production, a reduction atmosphere is formed by incombustible carbon included in the molding sand to increase the reactivity of the alkali metal and alkaline earth metal contained in the soil occurring in water purification plats and enable their reaction with silicon carbide.</p> |
