Coking of iron and steel
The whole smelting process of iron and steel industry from coking, sintering, ironmaking, steelmaking to rolling involves different types of pollutants, including waste gas, waste water and waste residue. Specifically, the sintering and coking links mainly produce sulfide, nitrogen oxide, smoke and dust and other waste gas, the iron making and steel-making links mainly produce slag and other solid wastes, while the pollutants produced in the steel rolling links mainly include wastewater pollution such as cooling water, among which the sulfide, nitrogen oxide, smoke and dust and other gas pollutants produced in the sintering and coking links are the most serious.
The waste gas produced by iron and steel industry is mainly sulfide, nitrogen oxide and soot, mainly from the pre iron links such as coking, sintering and pelletizing. Taking a long process large-scale iron and steel enterprise (9.7 million tons) as an example, the smoke / dust emitted by the enterprise mainly comes from the raw material system (19.5%), the iron making system (coking + sintering + pellet + iron making, 62.3%) and the steel making system (13.5%), which together account for 95.3% of the total smoke / dust emission of the iron and steel industry. Specifically, SO2 mainly comes from pellet (34.1%), sintering (25.1%) and self-contained power station (27.5%), accounting for 86.7% of the total emissions; NOx mainly comes from sintering (30.9%), self-contained power station (23%), pellet (15.1%) and coking (9.9%), accounting for 78.9% of the total emissions.