Affiliations: National Engineering Research Center for Flue Gas
Desulfurization, Department of Environmental Science and Engineering, Sichuan
University, Chengdu 610065, China
Abstract: MnO_2 in pyrolusite can react with
SO_2 in flue gas and obtain by-product
MnSO_4·H_2O. A pilot scale jet
bubbling reactor was applied in this work. Different factors affecting both
SO_2 absorption efficiency and Mn^{2+}
extraction rate have been investigated, these factors include temperature of
inlet gas flue, ration of liquid/solid mass flow rate (L/S), pyrolusite grade,
and SO_2 concentration in the inlet flue gas. In the
meantime, the procedure of purification of absorption liquid was also
discussed. Experiment results indicated that the increase of temperature from
30 to 70 K caused the increase of SO_2 absorption efficiency
from 81.4% to 91.2%. And when SO_2 concentration in the
inlet flue gas increased from 500 to 3000 ppm, SO_2
absorption efficiency and Mn^{2+} extraction rate decreased
from 98.1% to 82.2% and from 82.8% to 61.7%, respectively. The content of
MnO_2 in pyrolusite had a neglectable effect on
SO_2 absorption efficiency. Low L/S was good for both
removal of SO_2 and Mn^{2+} extraction.
The absorption liquid was filtrated and purified to remove Si, Mg, Ca, Fe, Al
and heavy metals, last product
MnSO_4·H_2O was obtained which
qualit could reach China GB1622-86, the industry grade standards.
