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Simultaneous NO x and SO 2 removal during wet flue gas desulfurization, using copper smelter slag slurry combined with yellow phorphorus
Author(s) -
Bao Jiacheng,
Xiao Helu,
Li Kai,
Wang Chi,
Song Xin,
Sun Xin,
Ning Ping,
Luo Yansu
Publication year - 2021
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.23925
Subject(s) - slurry , flue gas desulfurization , copper , dissolution , chemistry , slag (welding) , ozone , phosphorus , scrubber , metallurgy , aqueous solution , inorganic chemistry , materials science , organic chemistry , composite material
The study of copper slag has attracted the attention of scholars from both China and around the world. But few have paid attention to its applications in the simultaneous removal of SO 2 and NO x in wet flue gas desulfurization (WFGD), becasue WFGD technique is inappropriate for directly treating NO x owing to the low solubility of NO. This work aims to improve NO x removal efficiency in WFGD technology using copper slag slurry associated with the oxidation of NO x by yellow phosphorus. Different operating conditions, including dispersion of P 4 , solid‐liquid ratio, initial pH value of copper slag slurry, reaction temperature, oxygen content, and gas flow rate, were compared regarding the efficiency of SO 2 and NO x simultaneous removal. The characterizations were carried out on the liquid and solid part of fresh and spent copper slag slurry after filtration. The results indicated that a great amount of metals ions, such as Fe 3+ and Zn 2+ , were leached by reacting with produced acids (H 2 SO 4 , HNO 3 , and H 3 PO 4 ), which had a liquid‐phase catalytic oxidation on S IV species (SO 3 2− /HSO 3 − ), leading to promotion in absorption for SO 2 . The copper slag played a significant role in dispersing the yellow phosphorus and promoting ozone generation, thus improving NO x removal efficiency. The reaction pathway can be divided into three parts: (a) ozone generation induced by yellow phosphorus, (b) the oxidation of NO by O 3 and then dissolution in aqueous solution, and (c) the dissolution of SO 2 and the liquid‐phase oxidation for SO 2 through metal ions produced by the reaction between acid and copper slag.