Offgas, metallurgical dust concentrations

Fig. 4.1. Flowsheet for cooling, diluting and cleaning metallurgical offgas. Gas temperature is lowered from 1500 to 310 K. S02 concentration is lowered from 10-75 volume% S02 to 8-13 volume% S02. Dust plus vapor concentration is lowered from 10-200 g per Nm3 of gas to 0.001 g per Nm3 of gas. Efficient gas cleaning minimizes plugging of downstream catalyst and equipment. It also minimizes poisoning of the catalyst. It is the key to efficient, continuous long term metallurgical acid plant operation. Mercury-from-gas removal is described in Section 4.5.3.

---