Research On The Industrial Test Of Desulfurization By Adding Urea During Sintering Process

The Steel industry is one of important pillar industries of the development of our country's national economy and is also the main source of pollutants. The emission of SO₂ produced by iron ore sintering is more than 70% of the whole steel industry. As environmental issues become increasing acute and strict and environmental policies are being conducted, the desulfurization from sintering gas need to be executed immediately. Sintering flue gas owes the following characteristics, including large amount, remarkable flow fluctuations and lower pollutant concentration, which seriously restrict the effective remove of pollutants. Currently desulfurization processes have been widely applied but huge cost and serious financial burden should be paid. Under this background, it is critical and urgent to develop innovative on-line?source treatment? desulfurization method with higher efficiency and lower cost. The previous research by professor Long-Hongming of AnHui University of technology found that urea mixing in sintering raw materials presented good desulfurization effects through the sintering pot test. In this paper, the industrial test of desulfurization by adding urea during sintering was investigated firstly, which provides theoretical support for improvement and application of the innovative flue gas desulphurization process.During each experiment, the constant amounts of urea were added into specific position via sintering machine equipment reformed. The test was made by self-designed device, which was used to extract, filter and dry the flue gas, and then the SO₂ concentration of flue gas was detected by Testo350 flue gas analyzer. The concentration of SO₂ was decreased sharply after urea added into sintering materials. Compared with the experiment without adding urea, the desulfurization rate of adding urea by "0.08%" and “0.09%" are 78.5% and 84.8%, respectively and the emission of SO₂ concentration below 200 mg/m3, meanwhile it doesn't affect the quality and composition of sinter. The sulfur balance calculations without adding urea, the 61.9% S from raw materials carried by flue gas. After adding urea, 38.4%, 25.23%, 12.62% S from raw materials carried by?NH4?2SO4, flue dust and flue gas respectively.From this industrial test, adding urea is an effective technology to reduce SO₂ emission during the iron ore sintering. This technology with good desulfurization effects, simpler process, lower investment and operation cost, will has broad application prospect.