The composition design of these unusual glasses, their melting and crystallisation behaviour, crystal nucleation kinetics and the microstructures resulting from different thermal treatments are analysed 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 vitrification and displayed bulk crystallisation after thermal treatment, and was therefore chosen for a more detailed study. Crystallised materials with nanometric microstructures were obtained using suitable treatments. Fracture strength, hardness and chemical resistance tests were performed. A product with fine volumetric crystallisation, a high degree of crystallisation, 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. 27 refs.
Primary author(s): Ferreira E B; Zanotto E D; Scudeller L A M
Sao Carlos,Federal University; Usiminas Steel Co.
Source: Glass Sci.Technol.