The steel mill slag ballast I remember being loaded into scores of CB&Q Ballast hoppers at Illinois Slag and Ballast, was a very light gray (almost white) and extremely porous. This was in 1962-1967. They called it pop-corn slag. The molten slag came from International Harvester's South Chicago steel plant at 106th and Torrence Ave. directly to IS&B's elevated slag dump. There, they dumped the slag thimbles down the elevation. The molten slag was continually drenched with high volume water sprays. This caused the slag to puff up full of steam induced air holes. A large electric shovel worked the cool side of the elevation loading large chunks of slag into small dump cars. Short trains of the dump cars would be pushed by a small "critter" to the crusher/screening plant and out came ballast. I have been told that slag ballast made very poor ballast. It has been said that the slag was pounded into powder in service and then into mud when it rai
ned. I have attached a photo of the IS&B dump.
Regards...Jerry Albin, Homer Glen, IL