1 research outputs found
A hazardous waste from secodary aluminium metallurgy as a new raw material for calcium aluminate glasses.
A solid waste coming from the secondary aluminium industry was successfully vitrified in the ternary
CaO–Al2O3–SiO2 system at 1500 ◦C. This waste is a complex material which is considered hazardous
because of its behaviour in the presence of water or moisture. In these conditions, the dust can generate
gases such as H2, NH3, CH4, H2S, along with heat and potential aluminothermy. Only silica sand and calcium
carbonate were added as external raw materials to complete the glasses formula. Different nominal
compositions of glasses, with Al2O3 ranging between 20% and 54%, were studied to determine the glass
forming area. The glasses obtained allow the immobilisation of up to 75% of waste in a multicomponent
oxide system in which all the components of the waste are incorporated. The microhardness Hv values
varied between 6.05 and 6.62 GPa and the linear thermal expansion coefficient, ˛, varied between (62 and
139)×10−7 K−1. Several glasses showed a high hydrolytic resistance in deionised water at 98 ◦C.The authors thank the MEC for financing project CTM2005-
01964 and the company Recuperaciones y Reciclajes Roman S.L.
(Fuenlabrada, Madrid, Spain) for supplying Ald.We would also like
to thank Dr. M.A. Villegas and M. García-Heras for their helpful
insight and Mr. A. Delgado for his technical assistance. H. Tayibi
is grateful to the CSIC (Spanish National Research Council) for an
I3P contract (I3PDR-6-01)Peer reviewe