In the drying phase, heat is used to reduce, or entirely remove the moisture from the concentrate. 

A rotary dryer is the most common drying device used to dry concentrates. It includes a slowly rotating cylindrical drum, a furnace, a feed chute, a drain chute for the dried product, and exhaust gas pipes for conducting combustion gases and water vapor to the outside air. 

The concentrate prepared in the rotary dryer of the concentrating plant on the slope was transferred with a conveyor belt to the concentrate warehouse to await further transport to the smelter. The concentrates were dried to a moisture content of less than 8% in order to avoid freezing during transport in winter.