1. Combustion energy for heating & reduction ■ cheaper energy cost ■ large off-gas volume much carry-over dust, lower ZnO % in crude ZnO ■ low-temperature reactionlow Fe recovery rate(much iron oxide in clinkerremaining Zn & Pb in clinker 2. Most popular conventional process (rotary kiln) 3. RHF is popular for BF & BOF dust,“but not yet for EAF dust” ■ because of the sticking of chlorides and Zn 4. Large plant scale with high equipment cost ■ One unit for 4 to 5 EAFs even more or for one integrated steel plant