Calcination: Heat treatment carried out at high temperatures in air or inert gas flow is called calcination or roasting. Calcination is the process of thermal dissociation or crystal transformation of natural or artificial compounds; At this point, the compound dissociates into simpler compounds or undergoes a crystal transformation through heating. The thermal decomposition of carbonates is called calcination. Calcination operation can be used to directly process mineral raw materials to meet the requirements of subsequent processes, and can also be used in chemical beneficiation post-treatment to prepare chemical concentrates to meet user requirements for products.

The main physical and chemical changes during the high-temperature furnace calcination process are thermal decomposition. Mainly to remove volatile impurities such as chemically bonded water, CO2, NOx, etc. At higher temperatures, oxides may also undergo solid-phase reactions to form active compound states. Recrystallization can obtain tiny crystal forms, crystal sizes, pore structures, and specific surface areas. Sintering microcrystals appropriately to increase mechanical strength.

The main factors affecting the calcination process of high-temperature furnaces are: calcination temperature, gas phase composition, thermal stability of compounds, etc. Therefore, based on the thermal stability of various compounds, such as carbonates, oxides, hydrogen sulfide hydroxides, oxygen-containing acid salts, etc. By controlling the calcination temperature and gas phase composition, the composition of certain compounds can be selectively altered. Perform crystal transformation and use corresponding methods to remove impurities and separate and enrich useful functional groups.