| 摘要 |
<p>PURPOSE:Highly efficient, simultaneous removal of NOx and SOx is performed without being affected by O2 in exhauseted waste gas. In this process, NOx is changed into NO2, and the Ca base slurry containing Mg salt and antioxidizer is used to simultaneously absorb and to remove NOx and SOx. CONSTITUTION:Burnt waste gas is transmitted through the coolingdust remover 2 to the oxidizer 3, where NO is oxidized to NO2 by oxdizing agent. The gas is sent to the cleaning apparatus 6 to simultaneously remove NOx and SOx by cleaning with Ca base slurry containing Mg salt and antioxidizer. The treatment-finished slurry is transferred to the liquid-solid separator 9. The solid is made to slurry in the pulp bath 11, the slurry is sent to the oxidizing apparatus 12, where it is adjusted to pH 2 to 6 by sulfuric acid, oxidized by air and recovered as gypsum 16 through the liquid-solid separator 15. The filtrate from the separator 9 is sent to the adjusting bath 19 to be replenished with lime and transferred to the cleaning apparatus 6. Some portion of the filtrate is sent to the thermal decomposition apparatus 23, in which it is decomposed at 70 to 200 deg.C and pH 3 or less thereby to modify nitrogen compounds in the liquid into NH4 salts. The products are sent to the NH3 discharger 24 maintained at pH of greater than 8, in which NH3, gypsum and Mg(OH)2 are produced. Gypsum and etc are sent to the bath 19.</p> |
