This includes waste vegetable oil, flat glass, non-packaging plastics, tyres, contaminated soils, pulverised fuel ash and blast furnace slag.
en.wikipedia.org Similarly, the oxidized lead slag has to be removed when it forms to maintain the operation, and its removal also results in loss of silver.
en.wikipedia.org The pitch was not grassy, but covered with slag, which was also a reason to close down the stadium.
en.wikipedia.org Products which incorporate limestone, fly ash, blast furnace slag, and other useful materials with pozzolanic properties into the mix, are being tested and used.
en.wikipedia.org