Ultrasonic propagation in molten lithium, sodium and potassium silicates

Abstract

Velocity and attenuation of ultrasonic wave in molten alkaline silicates of lithium, sodium and potassium were measured at a temperature range between their liquidus and ∼200 K higher than their liquidus. Measurements were carried out by the pulse transmission method using a couple of ultrasonic pulse generator and receiver. Composition of the silicate sample was selected for covering the enough temperature range and for getting the correct knowledge of composition dependence of alkaline silicate. Measured velocity of ultrasound decreases with the increase in temperature in all samples. Composition dependence were similar between sodium and potassium silicates but little different in lithium silicate. Absorption of ultrasound depends both on the sound frequencies and temperatures. It suggests that there is some dispersion of sound waves propagating in the silicate medium. Since the lithium silicate melt behaves in a dissimilar way from those of other alkaline silicates, the authors tried the additional measurement on the pseudobinary system of lithium and sodium disilicate system. The results are discussed from the structural aspect comparing with the previous work on Ni ion colour indicator.