软锰矿浆烟气同步脱硫脱硝资源化利用新工艺

燃煤烟气中的SO2和NOx是大气中重要的污染物,开发高效、经济的同步脱硫脱硝技术是环保领域的研究热点。针对现有同步脱硫脱硝技术存在的氧化剂成本较高和产物不能资源化利用等突出问题,提出了软锰矿浆烟气同步脱硫脱硝,并副产硫酸锰和硝酸锰的资源化新工艺。研究结果表明:软锰矿浆可以有效的脱除烟气中的SO2和NOx,反应产物分别为硫酸锰和硝酸锰。在烟道中注入臭氧,将难溶于水的NO快速氧化为NO2,可大大提高脱硝效率,在O3/NO=1.2的条件下可以达到72%的脱硝率、90%的脱硫率和85%的锰浸出率;吸收液经过空气氧化除铁和加入铜试剂除重金属后,结晶分离溶液得到的硫酸锰和硝酸锰可分别达到HG/T 2962—1999标准的硫酸锰产品和HG/T 3817—2006标准的工业硝酸锰产品要求。该工艺实现了SO2和NOx污染治理与低品位软锰矿资源化利用的双重目的,为SO2和NOx的资源化污染治理技术的开发和应用提供了新的思路。

A NEW PROCESS OF SIMULTANEOUS REMOVAL OF SO2 AND NOx FROM FLUE GAS WITH PYROLUSITE SLURRY

It is an urgent issue in the field of environmental chemical engineering to find effective process for simultaneous removal of SO2 and NOx emissions which are the main atmospheric pollutants mainly from combustion of coal.Aiming at the fact that the current technologies of simultaneous removal of SO2 and NOx emissions have problems of high cost of oxidant and short use of resources,a new process of simultaneous removal of SO2 and NOx from flue gas and utilizing the by-products of MnSO4 and Mn(NO3)2 is raised.The results show that pyrolusite slurry can effectively remove SO2 and NOx from flue gas,producing MnSO4 and Mn(NO3)2,respectively.Adding ozone can greatly improve the wet denitration process,thus improving the NOx removal efficiency,and a result of NOx removal efficiency at 72%,SO2 removal efficiency at 90% and Mn extraction rate at 85% was obtained when ratin of O3/NO is 1.2.After purification and impurity of the absorbing liquid with air and DDTC,respectively,products of manganese sulfate and manganous nitrate can be achieved respectively,which can meet the requirements of HG/T 2962—1999 and HG/T 3817—2006,so as to prove that the process is feasible.The process realizes dual purpose of simultaneous desulfurization and denitrification by low grade pyrolusite,which provides a new thought for development and application of SO2 and NOx pollution treatment technology.