In clinker production, secondary and tertiary air are not only supplying oxygen to pulverized coal combustion, but are also important heat resource to rotary kiln and Calciner, furthermore, are the power source during material suspension, mixture, rotary spraying, spreading and other functions which are completed inside Calciner. Secondary and tertiary air are both originated from kiln hood, are of the same temperature and composition properties, one is for rotary kiln while another for Calciner, they are both vital elements in clinker production.

The formation of clinker is liquid phase sintering, higher reaction temperature would ensure higher synthesis rate. Given the same synthesis rate, the higher the temperature is, the shorter the reaction time takes, the faster the reaction speed is, high temperature has great impact to solid-state reaction spreading. The new dry-grinding process pursues shortest time-consuming and highest production output. Less time for reaction relies on higher reaction temperature, two elements determine temperature and clinker sintering efficiency which are secondary&tertiary air temperature and coal quality.