National Slag Limited

Lafarge Canada Inc.

Peter A MacKenzie

David T Horvat

Robert P Cotsworth

Michael Orlander

Kenneth W Spencer

Metallurgical slag is expanded to produce a lightweight solid by forming a stream of molten liquid slag of controlled rate of flow and mixing the stream of slag with a controlled quantity of water and flowing the interacting mixture of slag and water into a receptacle. The interaction between slag and water is allowed to proceed for a predetermined period of time to form an expanded solid without the addition of any additional cooling water which would otherwise quench the material and vitrify it. In the receptacle, a vaned rotor operates to segment the interacting mixture of slag and water and project the segmented mixture through the air for collection into a heap.

Process and apparatus for making expanded slag

An enclosure for slag pelletizers, and a method of operating such an enclosure, that minimizes the escape into the ambient atmosphere of airborne fibres produced by the pelletization process, while permitting the necessary free passage of the steam and gases that are also produced. The enclosure roof consists of at least one layer of wire mesh and a system of overlapping baffles is provided beneath the roof at least above the pelletizer to intercept the particulate material, so that the pellets do not disrupt a blanket of the fibre which is allowed to accumulate on the wire mesh to facilitate removal of the remainder of the fibre from the air stream. The method allows the deposition of an effective blanket, while preventing the deposition of too much fibre, so that the gas stream is diverted and flows out of the open end of the enclosure. A first plurality of water-mist producing nozzles is disposed between the mesh roof and the baffles, while a second plurality is disposed above the mesh roof both delivering a fine mist of water to wet fine particulate, causing it to deposit. A plurality of water-jet producing nozzles are disposed above the roof and delivers jets of water to wash the deposited particulate from the roof and baffle system down into the enclosure interior as and when required.

Enclosures for slag pelletization apparatus and method of operation

Apparatus for the pelletization of heat liquifiable materials, such as metallurgical slags consists of a downwardly-extending feed plate onto which the molten material is fed together with water, if required to promote the expansion of the molten material and for control of the cooling. The material discharges from the feed plate onto a rotating radially vaned drum by rotor by which it is projected into the air for simultaneous cooling and pelletization after it has first passed through a flow control gap formed between the feed plate surface and the periphery of a second rotor mounted above the feed plate. The second rotor is rotated in the direction such that it promotes the flow of the molten material down the plate, forcing the material between the vanes of the projecting rotor, while at the same time spreading the material across the width of the plate against its natural tendency to form a compact stream. The flow of the material is thereby made more uniform, providing for more effective use of the projecting rotor and avoiding localized flooding of the vanes with consequent loss of pelletization. The resulting apparatus can also be more compact for a given output. In some circumstances the second rotor can with advantage be rotated against the direction of flow down the feed plate.

Apparatus for the pelletization of heat-liquifiable solid materials

Apparatus for the pelletization of heat-liquifiable materials, such as metallurgical slags, consists of feed means for the molten material, these feed means depositing the material on a downwardly-extending feed plate over which it flows while it is mixed with water, if water is necessary to promote the expansion of the molten material and for control of the cooling. The material then flows on to a first rotating radially-vaned drum or rotor by which it is projected into the air for simultaneous cooling and pelletization. The feed means comprises flow control means such that any flow greater than a predetermined maximum is fed onto a second feed plate disposed above the first, from which the excess molten material flows on to a second rotating radially-vaned drum or rotor operative in like manner to the first. The flow control means may comprise for example a dam over which the excess material flows. Preferably both of the feed plates are mounted to vibrate and are vibrated by a rotating eccentric weight to reduce adhering of the material to the feed surface plate by thus reducing the heating thereof.

Growing community of inventors

Stoney Creek, Canada

Peter A MacKenzie