Sintering flue gas desulfurization waste activated carbon treatment system

Abstract

The utility model relates to a sintering flue gas desulfurization waste activated carbon treatment system, and belongs to the field of dangerous waste treatment of iron and steel plants. Waste activated carbon generated by sintering flue gas desulfurization is conveyed to a powder preparation site through a suction and discharge tank truck, is pumped into a waste activated carbon bin, is uniformly conveyed to a coal falling pipe above a coal mill in proportion through a blowing system, enters the coal mill together with raw coal, and is dried and ground into mixed powder to be used as fuel of a blast furnace, so that energy is effectively utilized, and the energy consumption is reduced. The problem of hazardous waste treatment is solved, and the environment is protected.

Description

Technical Field

[0001] The utility model relates to a sintering flue gas desulfurization waste activated carbon treatment system, belonging to the field of hazardous waste treatment in steel plants. Technical Background

[0002] Sintering is a complex physical and chemical process, producing flue gas characterized by low temperature, complex composition, and high emissions. SO2 emissions account for approximately 70% of total emissions from steel enterprises, and other pollutants such as NOx and heavy metals are also present. Therefore, desulfurization during the sintering process is particularly important. Desulfurization can be performed using wet, semi-dry, and dry methods. Activated carbon desulfurization has an efficiency of approximately 90%, and the desorption product can be used to produce sulfuric acid. Activated carbon also has a certain adsorption capacity for toxic dioxins and heavy metals. Currently, activated carbon used for sintering desulfurization is mostly cylindrical, with a particle size of less than 9 mm and a length of ≤15 mm. It contains ≥75% carbon, approximately 17% ash, an ignition point of ≥420°C, and a wear resistance of ≥97%, making it more resistant to wear and pressure than ordinary activated carbon. Activated carbon can be reused after desorption, but this adsorption and desorption process is not infinitely cyclic. Activated carbon inevitably loses its effectiveness due to factors such as reaction with certain gases during use, clogging of its pores by dust, and wear and tear after use. Waste activated carbon is unavoidable and is either non-regenerable or, after regeneration, has been processed through a vibrating screen to remove cracked activated carbon and its powder.

[0003] As more companies adopt activated carbon for sintering flue gas desulfurization, its usage continues to rise, and the amount of waste activated carbon generated is also increasing. Because activated coke adsorbs toxic substances such as sulfur and heavy metals, waste activated carbon powder from sintering desulfurization is a hazardous waste product that must be disposed of within the factory. Some companies employ sintering raw material additions, but this impacts sintering performance and results in very low utilization rates. Thermal power plants can dispose of waste activated carbon powder, but steel companies generally lack on-site thermal power generation facilities. Failure to effectively recycle and reuse the large amounts of waste activated carbon not only pollutes the environment but also represents a waste of resources. Summary of the Invention

[0004] In response to the existing problems, the following solutions are proposed:

[0005] The sintering flue gas activated carbon desulfurization system is connected to the waste activated carbon silo, the waste activated carbon silo is connected to the waste activated carbon injection system, the waste activated carbon injection system is connected to the coal drop pipe of the coal mill or the air inlet pipe of the coal mill, and the coal mill is connected to the bag powder collector and the coal powder silo in sequence.

[0006] The waste activated carbon injection system includes a silo top dust collector, a waste activated carbon silo, a valve I, a feeding tank, a valve II, a soft connection, a valve III, a weighing element, a injection tank, and a pipeline II.

[0007] Connect the discharge port of the suction tank truck to Pipeline I. Pneumatically pump the waste activated carbon into the waste activated carbon silo, with the conveying gas discharged through the silo's top dust collector. Open Valve I and load the waste activated carbon into the loading tank. Close Valve I and pressurize the loading tank. Once the pressure in the loading tank and the injection tank are balanced, open Valves III and II and load the waste activated carbon from the loading tank into the injection tank. Then, close Valves II and III. The waste activated carbon in the injection tank is continuously pumped through Pipeline II using nitrogen to the coal drop pipe or pulverizer inlet pipe. To precisely control the delivery rate, the waste activated carbon injection system is equipped with a weighing element and a flexible connection is installed between Valves II and III. Depressurize the loading tank to near zero, open Valve I and reload the loading tank. Repeat the above steps to continuously pump the waste activated carbon to the coal drop pipe or pulverizer inlet pipe.

[0008] The raw coal in the raw coal bunker is metered by the coal feeder and then enters the coal drop pipe, and is then ground into the coal mill together with the waste activated carbon. The waste flue gas from the hot blast furnace extracted by the high-temperature fan is mixed with the high-temperature flue gas from the flue gas furnace and enters the coal mill through the air inlet pipe. The mixed powder after grinding and drying is collected by the drying gas into the bag collector through pipeline IV and is then collected into the coal powder bunker. The filtered drying gas is discharged into the atmosphere through the main exhaust fan, and the mixed powder is used for coal injection in the blast furnace.

[0009] The components of spent activated carbon are as follows:

[0010] name ash content Volatile matter Sulfur content Fixed carbon Waste activated carbon% 10.87 26.24 3.69 62.89

[0011] Because the waste activated carbon contains too high sulfur and harmful elements such as heavy metals, adding it to the coal increases the sulfur load entering the blast furnace and increases the desulfurization burden. The waste activated carbon will also become compacted in the pipes and spray guns during the injection process into the blast furnace, clogging the spray guns. Therefore, strict control of the addition amount is required.

[0012] The proportion of waste activated carbon to raw coal is ≤5%.

[0013] The conveying gas for waste activated carbon is nitrogen, with a pressure ≥ 200kPa.

[0014] Nitrogen is used for transporting waste activated carbon, and the transport pipelines: pipeline I, pipeline II, and pipeline IV are made of wear-resistant materials.

[0015] The implementation of this patent is to transport the waste activated carbon to the coal drop pipe through the waste activated carbon injection system and enter the pulverizer together with the coal. The ground mixed powder is used as blast furnace fuel, which fully utilizes the carbon in the activated carbon, solves the problem of hazardous waste treatment, effectively utilizes energy, and protects the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of sintering flue gas desulfurization waste activated carbon treatment system Figure 1

[0017] Figure 2 Schematic diagram of sintering flue gas desulfurization waste activated carbon treatment system Figure 2

[0018] Legend Marker

[0019] 1 Coke suction and discharge tank car, 101 Pipeline I, 2 Waste activated carbon injection system, 201 Silo top dust collector, 202 Waste activated carbon silo, 203 Valve I, 204 Loading tank, 205 Valve II, 206 Flexible connection, 207 Valve III, 208 Weighing element, 209 Injection tank, 210 Pipeline II, 3 Coal mill, 301 High-temperature fan, 302 Flue gas furnace, 303 Air inlet pipe, 304 Coal drop pipe, 305 Coal feeder, 306 Raw coal silo, 307 Pipeline IV, 308 Bag powder collector, 309 Main exhaust fan, 310 Pulverized coal silo, 4 Sintering flue gas activated carbon desulfurization system. DETAILED DESCRIPTION

[0020] The following is a detailed description of the implementation of the present invention with reference to the accompanying drawings so that a person skilled in the art can easily implement the present invention. The present invention can be embodied in many different forms and is not limited to this description.

[0021] Example 1 Refer to the attached Figure 1

[0022] The sintering flue gas activated carbon desulfurization system 4 is connected to the waste activated carbon bin 202, the waste activated carbon bin 202 is connected to the waste activated carbon injection system 2, the waste activated carbon injection system 2 is connected to the coal drop pipe 304 of the coal feeder 305 through pipeline II 210, and the pulverized coal mill 3 is connected to the bag dust collector 308 and the pulverized coal bin 310 in sequence.

[0023] The outlet of the waste activated carbon injection system 2 is connected to the coal drop pipe, and the waste activated carbon enters the coal mill together with the coal.

[0024] Use suction and discharge tanker 1 to transport the waste activated carbon from the sintering flue gas activated carbon desulfurization system 4 to the waste activated carbon silo 202. Connect the discharge port of suction and discharge tanker 1 to pipeline I 101. Pneumatically convey the waste activated carbon into the waste activated carbon silo 202. The conveying gas is discharged through the silo top dust collector 201. The composition of the waste activated carbon is as follows:

[0025] name ash content Volatile matter Sulfur content Fixed carbon Waste activated carbon% 10.87 26.24 3.69 62.89

[0026] Open valve I 203 and load the waste activated carbon into the loading tank 204. Close valve I 203 and pressurize the loading tank 204. Once the pressure in the loading tank 204 and the injection tank 209 is balanced, open valves III 207 and II 205 and load the waste activated carbon from the loading tank 204 into the injection tank 209. Then close valves II 205 and III 207. The waste activated carbon in the injection tank 209 is continuously transported to the coal drop pipe 304 via pipe II 210 using nitrogen. To accurately control the delivery volume, a weighing element 208 is installed, and a flexible connection 206 is provided between valves II 205 and III 207. The loading tank 204 is depressurized to near zero, and then open valve I 203 to recharge the loading tank 204. Repeat the above steps to continuously transport the waste activated carbon to the drop pipe 304.

[0027] The raw coal (bituminous coal and anthracite) in the raw coal bin 306 is metered by the coal feeder 305 and then enters the coal drop pipe 304, and is ground together with the waste activated carbon into the coal mill 3. The waste flue gas from the hot blast furnace is extracted by the high-temperature fan 301 and mixed with the high-temperature flue gas from the flue gas furnace 302, and enters the coal mill 3 through the air inlet pipe 303. The ground and dried mixed powder is carried out by the drying gas, enters the bag powder collector 308 through the pipeline IV 307, and is collected in the coal powder bin 310. The filtered dry gas is discharged into the atmosphere through the main exhaust fan 309, and the mixed powder is used for coal injection in the blast furnace.

[0028] The ratio of waste activated carbon to raw coal is:

[0029] name Ash % Volatile matter% Sulfur content% Fixed carbon% Proportion% Anthracite coal 10.42 10.52 0.33 79.06 60 bituminous coal 5.69 34.68 0.38 59.63 38 Waste activated carbon 10.87 26.24 3.69 62.89 2 Mixed powder 8.63 20.02 0.42 71.35 100

[0030] Main equipment parameters:

[0031] Waste activated carbon silo: 90m 3

[0032] Feeding tank: 2.8m 3

[0033] Spray tank: 5.6m 3

[0034] Blowing capacity: normal 1.4t / h, maximum 5t / h

[0035] Coal mill: 70t / h

[0036] Further: Waste activated carbon accounts for 2% of raw coal, and 20 tons of waste activated carbon are consumed every day, which is the same as the output of waste activated coke produced by sintering flue gas desulfurization.

[0037] The conveying gas for waste activated carbon is nitrogen with a pressure ≥ 200kpa.

[0038] Nitrogen is used for transporting waste activated carbon, and the transport pipelines: pipeline I, pipeline II, and pipeline IV are made of wear-resistant materials.

[0039] Example 2 Refer to the attached Figure 2

[0040] The outlet of the waste activated carbon injection system 2 is connected to the air inlet pipe, and the waste activated carbon enters the coal mill together with the drying gas.

[0041] Use a suction tanker 1 to transport the waste activated carbon after sintering flue gas desulfurization to the pulverizing site 4. Connect the discharge port of the suction tanker to pipeline I 101, and use pneumatic conveying to pump the waste activated carbon into the waste activated carbon silo 202. The conveying gas is discharged through the silo top dust collector 201. The composition of the waste activated carbon is as follows:

[0042] name Ash % Volatile matter% Sulfur content% Fixed carbon% Waste activated carbon 10.87 26.24 3.69 62.89

[0043] Open valve I 203 and load the waste activated carbon into the loading tank 204. Close valve I 203 and pressurize the loading tank 204. Once the pressure in the loading tank 204 and the injection tank 209 is balanced, open valves III 207 and II 205 and load the waste activated carbon from the loading tank 204 into the injection tank 209. Then close valves II 205 and III 207. The waste activated carbon in the injection tank 209 is continuously transported to the coal drop pipe 304 via pipe II 210 using nitrogen. To accurately control the delivery volume, a weighing element 208 is installed, and a flexible connection 206 is provided between valves II 205 and III 207. The loading tank 204 is depressurized to near zero, and then open valve I 203 to recharge the loading tank 204. Repeat the above steps to continuously transport the waste activated carbon to the drop pipe 304.

[0044] The raw coal (bituminous coal and anthracite) in the raw coal bin 306 is metered by the coal feeder 305 and then enters the coal drop pipe 304 and enters the coal mill 3 for grinding. The waste flue gas from the hot blast furnace extracted by the high-temperature fan 301 is mixed with the high-temperature flue gas from the flue gas furnace 302, and enters the coal mill 3 together with the waste activated carbon through the air inlet pipe 303. The ground and dried mixed powder is carried out by the drying gas, enters the bag powder collector 308 through the pipeline IV 307, and is collected in the coal powder bin 310. The filtered drying gas is discharged into the atmosphere through the main exhaust fan 309. The mixed powder is used for coal injection in the blast furnace.

[0045] The ratio of waste activated carbon to raw coal is:

[0046] name Ash % Volatile matter% Sulfur content% Fixed carbon% Proportion% Anthracite coal 10.42 10.52 0.33 79.06 60 bituminous coal 5.69 34.68 0.38 59.63 38 Waste activated carbon 10.87 26.24 3.69 62.89 2 Mixed powder 8.63 20.02 0.42 71.35 100

[0047] Main equipment parameters:

[0048] Waste activated carbon silo: 90m 3

[0049] Feeding tank: 2.8m 3

[0050] Spray tank: 5.6m 3

[0051] Blowing capacity: normal 1.4t / h, maximum 5t / h

[0052] Coal mill: 70t / h

[0053] Further: Waste activated carbon accounts for 2% of raw coal, and 20 tons of waste activated carbon are consumed every day, which is the same as the output of waste activated coke produced by sintering flue gas desulfurization.

[0054] The conveying gas for waste activated carbon is nitrogen with a pressure ≥ 200kpa.

[0055] Nitrogen is used for transporting waste activated carbon, and the transport pipelines: pipeline I, pipeline II, and pipeline IV are made of wear-resistant materials.

Claims

1. A sintering flue gas desulfurization waste activated carbon treatment system, characterized in that: The sintering flue gas activated carbon desulfurization system is connected to the waste activated carbon silo, the waste activated carbon silo is connected to the waste activated carbon injection system, the waste activated carbon injection system is connected to the coal drop pipe of the coal mill or the air inlet of the coal mill, and the coal mill is connected to the bag powder collector and the coal powder silo in sequence.

2. The system for treating waste activated carbon from sintering flue gas desulfurization according to claim 1, characterized in that: The waste activated carbon produced by the sintering flue gas activated carbon desulfurization system is transported to the waste activated carbon silo via suction and discharge tank trucks or pneumatic conveying.

3. The system for treating waste activated carbon from sintering flue gas desulfurization as claimed in claim 1, characterized in that: The waste activated carbon is activated carbon powder eliminated from sintering flue gas activated carbon desulfurization and cannot be regenerated.

4. The system for treating waste activated carbon from sintering flue gas desulfurization as claimed in claim 1, characterized in that: The waste activated carbon injection system is equipped with a weighing and metering device.

5. The system for treating waste activated carbon from sintering flue gas desulfurization as claimed in claim 1, characterized in that: The proportion of waste activated carbon to raw coal is ≤5%.

6. The system for treating waste activated carbon from sintering flue gas desulfurization as claimed in claim 1, characterized in that: The waste activated carbon injection system uses nitrogen as the conveying gas, and the conveying pipeline is made of wear-resistant materials.

Images