The investigation
of the dielectric properties of bastnasite concentrate
has critical directing centrality for the microwave roasting process
of bastnasite concentrate. The dielectric properties are correlated
with information such as thermogravimetry–differential scanning
calorimetry and temperature rise curves. This combination permits
a targeted study of the mechanism of the microwave roasting process,
providing new evidence about the unique conditions of this microwave
roasting process. This work also explores the response surface methodology
based on a central composite design to optimize the microwave non-oxidative
roasting process. Single-factor tests were conducted to determine
the suitable range of factors such as the content of activated carbon,
holding time, and roasting temperature. The interactions between parameters
were investigated through the analysis of variance method. It was
indicated that the models are available to navigate the design space.
Also, the optimal roasting temperature, content of activated carbon,
and holding time were 1100 °C, 20%, and 21.5 min, respectively.
Under these conditions, the decomposition rate of bastnasite concentrate
(hereinafter to be referred as DRBC) and the oxidation rate of cerium
(hereinafter to be referred as ORC) was 99.8% and less than 0.3%,
respectively. The new non-oxidizing roasting method significantly
shortens the roasting time, reduces the energy consumption, and has
great significance for industrial applications.