Abstract
Effects of alkali and alkaline earth metal ions on sintering and the thermal expansion behaviors of nepheline were investigated. Densification at lower sintering temperatures was promoted y Li2CO3 or Na2CO3 addition. The thermal expansion of nepheline decreased on substitution of Li+ for Na+, and increased on substitution of K+ for Na+. Nepheline solid solutions in the system MxNa1-xAlSiO4 (M=Li and K) had mean axial thermal expansion coefficients ranging from 14×10-6/°C to 20×-6/°C from room temperature to 1000°C.
