| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a high-strength and inexpensive molded product in which a heavy metal contained in a waste is stably fixed in the interior thereof by preparing a molding raw material containing the waste and a crushed stone sludge, molding the resultant raw material into a prescribed shape and then sintering the molded product. SOLUTION: A waste is an incineration ash (including a fly ash) produced by incinerating combustibles such as a municipal refuse, a general refuse, a domestic refuse, an industrial refuse, a sewage sludge or a shredder dust, a slag prepared by melting the incineration ash, a dredged mud of lakes and marshes, a sludge rejected in a purifying step of various minerals, a slag or the like. The crushed stone sludge is prepared by separating and recovering sand or mud sticking to the crushed stone. The mixing ratio of the crushed stone sludge based on the waste is preferably >=30 and <=65%. The sintering maximum temperature of a molded product is preferably 1,050 to 1,200 deg.C and the temperature holding time is preferably <=2 h. The molded product is preferably cooled from the maximum temperature to 900 deg.C in <=0.15 h and further cooled to 300 deg.C in 1-3 h. The resultant sintered compact is capable of stably fixing a heavy metal and has a high strength and a high surface strength.</p> |
