Modified calcination conditions of rare alkali metal Rb-containing muscovite (KAl2[AlSi3O10](OH)2)

Muscovite mineral was roasted in different conditions. Rubidium leaching rate was a standard to examine the impact of various factors on calcination effect, including the agent types, roasting time, mass ratio, and roasting temperature. The results indicate that the best agent is the combination of sodium chloride and calcium chloride, and its mass ratio of muscovite/NaCl/CaCl2 is 1.00:0.25:0.25. Calcined at 850 °C for 30 min, the rubidium leaching rate is up to 90.12 %. The reaction of muscovite ore with the chlorinating agent CaCl2 was studied by TG/DSC, and the surface morphology before and after leaching was characterized by SEM. Rubidium chloride products can be obtained using t-BAMBP extraction, hydrochloric acid re-extraction, and purification.