Glass and glass-ceramic from basic oxygen furnace (BOF) slag

A method is presented to produce glass-ceramics from a BOF slag glass containing a high amount of iron. The composition design of these unusual glasses, their melting and crystallization behavior, their crystal nucleation kinetics and the microstructures resulting from different thermal treatments are analyzed and discussed. Several compositions were tested, varying the proportions of slag, sand and Na2CO3 in the batch. A batch with a composition (in wt%) of 60 slag, 35 sand, 5 Na2O showed good vitrificability and displayed bulk crystallization after thermal treatment, and was therefore chosen for a more detailed study. Crystallized materials with nanometric microstructures were obtained using suitable treatments. Fracture strength, hardness and chemical resistance tests were performed. A product with fine volumetric crystallization, a high degree of crystallization, having marble-like appearance, improved mechanical strength and suitable chemical durability was obtained. The material may be suitable for floor and wall tile applications in the construction industry.