According to different burning temperature and burning time of limestone in lime shaft kiln, basically quicklime has 3 different types: high reactive quicklime, medium reactive quicklime, low reactive quicklime. We can also call it soft-burnt quicklime, medium-burnt quicklime, hard-burnt quicklime.
The above scanning electron microscope images show the structure of highly reactive lime on the left, medium reactive lime in the middle and low reactive lime on the right. In this context, one also speaks of soft-burnt, medium-burnt or hard-burnt lime.
