Phase Transformation of Coal Tailing of Beneficiation with the Addition of Na2CO3 at High Temperature

Abstract

To use a tailing obtained from coal beneficiation as a raw material for glass material, the behaviors of phase transformation of the tailing was investigated according to sintered temperature with the addition of Na2CO3. As a result of the experiment, mullite was formed at 700~1,100 °C, and the mullite and the cristobalite just only existed at 1,450 °C. The glassification ratio of the coal tailing was to be 97.9 wt.% at 1,450 °C with the addition of Na2CO3 to tailing weight ratios of 10 wt.%. However, in the case of sample of coal tailing with 20 wt.% Na2CO3 added, nepheline(Na2O·Al2O3·2SiO2) was produced during the re-sintering(2nd sintering) at 1,100 °C. From the results, the suitable addition amount of Na2CO3 for glassification of coal tailing was found around 10 wt.%.