Method for producing a sand-like slag and slag dust with molten slag ash

摘要

PURPOSE: To obtain a pavement material by melting incineration ashes of refuse, sewer sludge, etc., solidifying the molten slag separated from molten metal by air cooling and pulverizing the solidified slag to sandy slag of a specific grain size from which sharp angled parts are removed by an autogenous mill. ;CONSTITUTION: The incineration ashes 4 of the refuse, sewer sludge, etc., charged into a melting furnace 1 is melted by the electric resistance heat generated from electrodes 3 and is gravity separated to the molten slag 5 and the molten metal 6. The molten slag 5 is poured into the mold in an air cooled slag conveyor 10 through a slag trough 9 and is cooled to solidify while the molten slag is transported. The massive solidified slag 25 is carried by a slag transporting conveyor 11 to the autogenous mill 12 provided with a casing 13 and a rotary drum 14 where the solidified slag is pulverized under heat radiation. The pulverized slag from which the sharp angled parts are removed is passed through a sieve 15a to form the sandy slag 26 of the grain size of about ≤5mm which is then sent by a pulverized slag transporting conveyor 16 to a slag pit 17 and is stored therein. A negative pressure is maintained in the autogenous mill 12 by an exhauster 24 and the suspended fine powder slag 27 generated at the time of pulverization is recovered by a bag filter 18a and a cyclone 18b.;COPYRIGHT: (C)1996,JPO