Research on properties and thermal stability mechanism of aluminum-niobium slag.

To develop and utilize aluminum-niobium slag, a kind of non-ferrous metallurgical waste residue produced in the preparation of metal niobium by the aluminothermic reduction method, the chemical composition, phase composition, microstructure and properties of aluminum-niobium slag were studied by ICP, XRD, SEM, TG-DTA and other characterization techniques. The results show that the oxidation of Nb and NbO leads to the poor volume thermal stability of aluminum-niobium slag. After heat treating the aluminum-niobium slag at different temperatures (400 - 1 500 °C), it is found that high temperature pre-firing treatment can effectively solve the problem of poor volume thermal stability of the aluminum-niobium slag. After pre-firing at 1 400 °C or above, the aluminum-niobium slag has stable phase composition and volume change rate as well as the refractoriness >1 790 °C, which meets the basic requirements of refractories for raw materials and lays a good foundation for its resource utilization. [ABSTRACT FROM AUTHOR]