PHASE-PURE MULLITE PROPPANT FROM CALCINED FLINT CLAY WITH A DOLOMITE CONTENT

摘要

In this work, a phase-pure mullite proppant was prepared from calcined flint clay with a dolomite content at 1400 degrees C. The phase composition and microstructure of proppant samples were investigated through X-ray diffraction and scanning electron microscopy. In addition to the apparent density, the breakage ratio was systematically investigated as a function of the content of dolomite. The results showed that the addition of dolomite went against the formation of cristobalite and promoted amorphous SiO2 to react with Al2O3 to form mullite. Additionally, when the content of dolomite was 4 % of mass fractions, the breakage ratio of the pure-mullite ceramic proppant was the lowest, under 52 MPa. The observation that, in the presence of dolomite, calcined flint clay can act as a precursor material for phase-pure mullite is of great industrial significance.