Study on Sintered Glass Ceramics from Nb-Ta Tailings

In this paper, particle sintering technology was used to transform tantalum niobium tailings (Nb-Ta tailings) into glass ceramic products. CaO, ZnO and BaO were used to adjust the composition of the glass. beta-wollastonite was found as the major crystalline phase in all treated samples. With the CaO increasing, the intensity of crystal diffractive peaks is also increasing. The formation of beta-wollastonite crystal can be accelerated by the increasing of CaO. The sintering is processed under the participation of liquid phase, and the increase of sintering temperature does a great favor on descending the liquid phase viscosity of glass particles, which consequently is available for sintering. The density and sintering quality of the samples prepared by two-step sintering are higher than that of one-step sintering. As the sintering temperature increases, the surfaces of the samples become better and have beautiful luster.