PRODUCTION OF ARTIFICIAL LIGHT-WEIGHT AGGREGATE AND ARTIFICIAL LIGHT-WEIGHT AGGREGATE PRODUCED THEREBY

摘要

PROBLEM TO BE SOLVED: To provide a process for producing an artificial light-weight aggregate capable of efficiently producing a harmless aggregate from refuse incineration ash and having high strength and low water-absorption while promoting the evaporation of heavy metals and harmful substances in the baking of the aggregate and provide an artificial light-weight aggregate produced by this process. SOLUTION: The objective process for the production of an artificial light- weight aggregate comprises the crushing of a mixture produced by mixing refuse incineration ash with a binder, a foaming agent, a reducing agent and silica and/or alumina as a composition controlling agent, the addition of water to the crushed mixture, the forming and optional drying of the product and two-stage baking of the formed material comprising the 1st stage baking at 850-1050 deg.C and the 2nd stage baking at 1060-1200 deg.C. The calcium content of the baked aggregate in the formed material is =16 wt.% in terms of oxide, the foaming agent is iron oxide and/or silicon carbide and the reducing agent is a carbon material. The artificial light-weight aggregate produced by this process has an absolute-dry specific gravity of =1.5 and 2.0, a uniaxial compressive strength of =50 kgf and a water-absorption of =5%.