| 摘要 |
<p>A process is disclosed for the production of light-weight aggregate by pelletization of slag materials, particularly blast furnace slags of base/acid ratio below 1.1, which otherwise have proven difficult if not impossible to pelletize to the commercially required density specification for the pelletized material. The molten slag is poured to form a stream and from about 50 to about 400 pounds per ton of finely-divided inert mineral particulate is added thereto, together with or followed by sufficient water to obtain foaming and a desired pyroplastic state. The exact amount of added material will depend among other factors such as the desired density and particle size of the pelletized material. The pyroplastic slag mixture is then impinged upon a rotating projector, which throws it into the air for a distance sufficient to ensure that it will cool and harden to the extent that the particles retain their individual identities upon reaching the ground. The added mineral material acts to control the cooling rate of the molten slag; due to the similar values of their specific gravities they blend with the molten slag much more readily than the water. Suitable materials for addition are, for example, crushed or screened fine slag and sands, for example waste foundry sand.</p> |
