GB1032608A - Method of and apparatus for processing molten slag and the like - Google Patents

Abstract

Molten slag is converted into expanded aggregate by continuously dispersing a falling stream of slag into pellets by a blast of gas, the pellets being thereafter projected through a spray of water, to expand the slag and increase its porosity, from which they emerge still somewhat plastic and incandescent to roll over a cooled surface to surface glaze them, to give them a generally spherical contour and to effect further cooling of them. The stream of slag falls from a water-cooled trough 2 in front of a nozzle 3 through which the gas, e.g. air or steam, is passed; the nozzel 3 is substantially the full width of the stream of slag. The pellets of slag are projected by the gas through an expansion 4 wherein they pass through a mist of atomised water discharged from nozzles 5 located in a generally semi-circular arrangement round the nozzle 3, the pellets subsequently impinging upon a concave disc 7 which is carried on a shaft 8 and rotated by a motor 9. The disc 7 is cooled by one or more water sprays 10, a water drain trough 10a being provided for collecting excess water. Additional cooling water may be supplied through a nozzle 12 directed preferably at the peripheral portion of the disc. Internal cooling of the disc may be provided. The pellets are sufficiently cooled on the disc so that after they fall from the latter they will not fuse or sinter together to any appreciable extent; the pellets are removed by an endless conveyer 13. In a second embodiment, Fig. 2 (not shown), the disc 7 is replaced by a hollow metal cone so that the pellets will be retained on the revolving surface for a longer period. The nozzle 12 may be replaced by nozzles supplying a water spray or a blast of cool air into the cone interior. In a modification, Fig. 3 (not shown), a rotating disc is disposed in a plane which is at an angle to the horizontal. <PICT:1032608/C6-C7/1>ALSO:<PICT:1032608/C1/1> Molten slag, or other compositions of ceramic or glass-forming ingredients, is converted into expanded aggregate by continuously dispersing a falling stream of slag into pellets by a blast of gas, the pellets being thereafter projected through a spray of water, to expand the slag and increase its porosity, from which they emerge still somewhat plastic and incandescent to roll over a cooled surface to surface glaze them, to give them a generally spherical contour and to cool them further. The stream of slag falls from a water-cooled trough 2 in front of a nozzle 3 through which the gas, e.g. air or stream, is passed; the nozzle 3 is substantially the full width of the stream of slag. The pellets of slag are projected by the gas through an expansion chamber 4 wherein they pass through a mist of atomized water discharged from nozzles 5 located in a generally semi-circular arrangement round the nozzle 3, the pellets subsequently impinging upon a concave metal disc 7 which is carried on a shaft 8 and rotated by a motor 9. The disc 7 is cooled by one or more water sprays 10, a water drain trough 10a being provided for collecting excess water. Additional cooling water may be supplied through a nozzle 12 directed preferably at the peripheral portion of the disc. Internal cooling of the disc may be provided. The pellets are sufficiently cooled on the disc so that after they fall from the latter they will not fuse or sinter together to any appreciable extent; the pellets are removed by an endless conveyer 13. In a second embodiment, Fig. 2 (not shown), the disc 7 is replaced by a hollow metal cone so that the pellets will be retained on the revolving surface for a longer period. The nozzle 12 may be replaced by nozzles supplying a water spray or a blast of cool air into the cone interior. In a modification, Fig. 3 (not shown), a rotating disc is disposed in a plane which is at an angle to the horizontal.