Analysis of the ash characteristic during co-firing of platanewood and bitumite

The appropriate ashing temperature, ashing time and ash characteristics of co-firing of platanewood and bitumite were studied by SEM/EDS analysis, X-ray diffraction and ash fusion experiment. It was found that the appropriate ashing time was 2 h. The ashing temperature should be adopted at 650, 700 and 800 ℃ according to the different proportions of platanewood proportion. With the increasing of platanewood proportion, the SiO₂ and Al₂O₃ contents decrease, but the contents of K₂O, CaO and MgO are the reverse, the Na₂O and Fe₂O₃ contents are at a low level which have no obvious trendy change. Anorthite appears in the ash with the 30% mixture ratio. The albite appears and the mullite disappears with the 50% mixture ratio. The crystalline phase intensity reduces with the increasing of ashing temperature. The aluminosilicate formed by alkali oxides with high content in the platanewood ash and silicon, aluminum oxide is the immediate cause of a low ash fusion point.