| 摘要 |
<p>PURPOSE: To efficiently remove SO2 and HCl by oxidizing gaseous SO2 of waste gases to make sulfate, acting Ca ions thereon and settling calcium sulfate particulates, then thermally hydrolyzing a chloride component. CONSTITUTION: When the waste gases contg. the HCl and SO2 released from a waste incineration plant are brought into contact with an aq. suspension of Mg(OH)2 within a purifying device 1, the greater part of the Mg(OH)2 is converted to MgCl2 and MgSO4 and sulfite is oxidized to sulfate. The formed CaSO4 and CaCl2 are sent to a spray roasting device 7 where the MgCl2 salt water is decomposed to MgO and HCl by thermal hydrolysis. The HCl is absorbed in an adiabatic absorption column 8 and is made into 15 to 18 mass % hydrochloric acid which is taken out as a product from D. The used purifying liquid is sent to a settling and concentrating device 2. The MgCl2 and MgSO4 are recovered from the overflowing liquid therefrom and are sent to a vacuum evaporator 3.</p> |
