Method for reducing emission of flue gas pollutants in sintering process

Abstract

The invention provides a method for reducing emission of flue gas pollutants in a sintering process. The method comprises the following steps: step one, measuring and taking water and quick lime, adding water into the quick lime, slaking the quick lime to obtain slaked lime, adding coked wastewater into the slaked lime, mixing and wetting; step two, mixing and wetting the slaked lime with the coked wastewater, then pelletizing, continuing to dropwise adding the coked wastewater in the pelletizing process, adjusting a pelletizing device and pelletizing the slaked lime; step three, conveying pelletized pellets into a sintering machine pellet distributing opening by using a material conveying belt; step four, distributing the material on the sintering machine; and step five, carrying out sintering treatment by igniting on the sintering machine after finishing distributing the material on the sintering machine, and completing sintering in the sintering machine. The facilities used by the method are simple; the existing sintering machine does not need to be greatly changed; the emission of the sintering flue gas is reduced while the coked wastewater can be consumed; the method can be used as the beneficial complement of the existing sintering flue gas treatment process; the burden of treatment at the end of sintering can be reduced.

Description

technical field

[0001] The invention relates to the field of iron and steel sintering, in particular to a method for reducing the emission of flue gas pollutants in the sintering process. Background technique

[0002] my country's iron and steel production is dominated by the blast furnace-converter "long process", and the proportion of converter steel is 90%. The sintering process is the main production process of blast furnace raw materials in my country. Sintered ore accounts for 70% to 75% of the blast furnace charge. In 2014, the output of sintered ore in my country exceeded 1 billion tons. At the same time, the impact of sintering production on the environment is also very large, and it is one of the most important processes for the emission of air pollutants in iron and steel complexes. The emission of pollutants has two characteristics: First, there are many types of pollutants, mainly including smoke dust, SO 2 , NO X , Dioxins, fluorides, heavy metals (lead, arse...

Examples

Embodiment 1

[0041] Step 1. Measure water and quicklime. The quality of water is 62% of the total mass. Water is added to quicklime for digestion to obtain slaked lime (1), and coking waste water (3) is added to slaked lime (1) for mixing and wetting. The total mass of coking wastewater (3) is 8% of the total mass of coking wastewater and slaked lime. Among them, the main components of coking wastewater are: COD: 2943.27mg / L; BOD: 1170.81mg / L; ammonia nitrogen: 271.82mg / L; TN: 449.19mg / L; volatile phenol: 584.67mg / L; sulfide: 100.13mg / L; Thiocyanide: 259.37mg / L.

[0042] Step 2: Slaked lime (1) and coking wastewater (3) are mixed and wetted, and then pelletized by a disc pelletizer (4) or a drum. During the pelletizing process, continue to add coking wastewater (3) dropwise until the total mass of the added coking wastewater (3) is 15% of the total mass of the coking wastewater and slaked lime, and adjust the pelletizing equipment so that the pellet size of the slaked lime (1) is 3 mm. ...

Embodiment 2

[0053] Step 1. Measure water and quicklime. The quality of water is 70% of the total mass. Add water to quicklime for digestion to obtain slaked lime (1), add coking wastewater (3) to slaked lime (1) for mixed wetting, and coking wastewater (3) The mass is 10% of the total mass of coking wastewater and slaked lime. Among them, the main components of coking wastewater are: COD: 2943.27mg / L; BOD: 1170.81mg / L; ammonia nitrogen: 271.82mg / L; TN: 449.19mg / L; volatile phenol: 584.67mg / L; sulfide: 100.13mg / L; Thiocyanide: 259.37mg / L.

[0054] Step 2: Slaked lime (1) and coking wastewater (3) are mixed and wetted, and then pelletized by a disc pelletizer (4) or a drum. Continue to add coking waste water (3) dropwise during the pelletizing process until the quality of the total coking waste water (3) added is not greater than 18% of the total mass of the coking waste water and slaked lime, and adjust the pelletizing equipment so that the pellet size of the slaked lime (1) reaches 5mm ...

technical field

[0001] The invention relates to the field of iron and steel sintering, in particular to a method for reducing the emission of flue gas pollutants in the sintering process. Background technique

[0002] my country's iron and steel production is dominated by the blast furnace-converter "long process", and the proportion of converter steel is 90%. The sintering process is the main production process of blast furnace raw materials in my country. Sintered ore accounts for 70% to 75% of the blast furnace charge. In 2014, the output of sintered ore in my country exceeded 1 billion tons. At the same time, the impact of sintering production on the environment is also very large, and it is one of the most important processes for the emission of air pollutants in iron and steel complexes. The emission of pollutants has two characteristics: First, there are many types of pollutants, mainly including smoke dust, SO 2 , NO X , Dioxins, fluorides, heavy metals (lead, arse...

Examples

Embodiment 1

[0041] Step 1. Measure water and quicklime. The quality of water is 62% of the total mass. Water is added to quicklime for digestion to obtain slaked lime (1), and coking waste water (3) is added to slaked lime (1) for mixing and wetting. The total mass of coking wastewater (3) is 8% of the total mass of coking wastewater and slaked lime. Among them, the main components of coking wastewater are: COD: 2943.27mg / L; BOD: 1170.81mg / L; ammonia nitrogen: 271.82mg / L; TN: 449.19mg / L; volatile phenol: 584.67mg / L; sulfide: 100.13mg / L; Thiocyanide: 259.37mg / L.

[0042] Step 2: Slaked lime (1) and coking wastewater (3) are mixed and wetted, and then pelletized by a disc pelletizer (4) or a drum. During the pelletizing process, continue to add coking wastewater (3) dropwise until the total mass of the added coking wastewater (3) is 15% of the total mass of the coking wastewater and slaked lime, and adjust the pelletizing equipment so that the pellet size of the slaked lime (1) is 3 mm. ...

Embodiment 2

[0053] Step 1. Measure water and quicklime. The quality of water is 70% of the total mass. Add water to quicklime for digestion to obtain slaked lime (1), add coking wastewater (3) to slaked lime (1) for mixed wetting, and coking wastewater (3) The mass is 10% of the total mass of coking wastewater and slaked lime. Among them, the main components of coking wastewater are: COD: 2943.27mg / L; BOD: 1170.81mg / L; ammonia nitrogen: 271.82mg / L; TN: 449.19mg / L; volatile phenol: 584.67mg / L; sulfide: 100.13mg / L; Thiocyanide: 259.37mg / L.

[0054] Step 2: Slaked lime (1) and coking wastewater (3) are mixed and wetted, and then pelletized by a disc pelletizer (4) or a drum. Continue to add coking waste water (3) dropwise during the pelletizing process until the quality of the total coking waste water (3) added is not greater than 18% of the total mass of the coking waste water and slaked lime, and adjust the pelletizing equipment so that the pellet size of the slaked lime (1) reaches 5mm ...

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