Method for resourceful treatment of dolomite powder solid waste through linkage of KR and converter

Abstract

The invention discloses a KR and converter linkage resource treatment method for dolomite powder solid waste, and the method comprises the following steps: a, loading the dolomite powder solid waste by using a tank car, and conveying the dolomite powder solid waste to a KR desulfurization station; b, in a KR desulfurization station, conveying dolomite powder from a tank car to a KR desulfurization powder bin; c, operating the KR stirring system; d, a KR feeding system is operated, specifically, the KR desulfurization powder bin conveys materials into a weighing hopper through a rotary feeder; e, treating according to a shallow desulfurization mode, and finishing feeding; f, after the cross-shaped stirring head is lifted out of the liquid level of the molten iron, lifting is stopped, and the cross-shaped stirring head is rotated for slag throwing; g, after slag throwing, KR stirring is completed; h, the molten iron in the desulfurized molten iron tank is not subjected to slagging-off treatment; and i, removing effective CaO brought by dolomite powder when the converter first batch material is added. According to the method, resource utilization of effective calcium oxide and magnesium oxide in the dolomite powder solid waste in converter slagging is achieved.

Description

Technical Field

[0001] The invention relates to the field of smelting technology, and in particular to a method for resource-based disposal of dolomite powder solid waste by linkage of KR and converter. Background Art

[0002] Dolomite powder refers to the screening product of natural dolomite blocks before entering the rotary kiln and the screening product of light-burned dolomite before supplying steelmaking, with a particle size of ≤5mm. In the past, dolomite powder was used as a flux for small blast furnaces. After the small ironmaking was shut down due to environmental issues, the stockpile of this type of material increased year by year. The accumulated dolomite powder occupies the site and raises dust in the wind; if it is not used for a long time, it will heat up and deteriorate when it comes into contact with water, and its volume will continue to increase. It is corrosive and is not good for air and water quality, which puts great pressure on enterprises to protect the environment.

[0003] In order to dispose of dolomite powder, attempts were made to transport the powder to the high-level silo of the converter through the underground silo of the converter and use it as a slag-making material for the converter. However, during use, problems such as blockage of the converter summary silo and failure of the converter fan occurred. An attempt was also made to dispose of it by bagging it into the converter, but the series of links such as bagging, transporting, and putting the powder into the scrap steel bucket were labor-intensive and affected the converter operating rate. Considering the economy and continuous production, both the high-level silo and bagging into the converter could not be implemented. Therefore, it is necessary to find a way to deal with the increasing amount of dolomite powder solid waste. Summary of the invention

[0004] In view of the above technical problems, the present invention provides a method for resource-based disposal of dolomite powder solid waste by linking KR and converter.

[0005] In order to achieve the above object, the technical solution of the present invention is as follows: A method for resource-based disposal of dolomite powder solid waste by KR and converter linkage, comprising the following steps: a. Use tank trucks to load dolomite powder solid waste with a particle size of ≤5mm and transport it to the KR desulfurization station; b. At the KR desulfurization station, the dolomite powder is transported from the tank truck to the KR desulfurization powder silo with an effective volume of 80m3; c. Operate the KR stirring system: insert the cross-shaped stirring head into the desulfurized iron ladle containing 86-92 tons of molten iron, and then rotate the cross-shaped stirring head to make the molten iron form a vortex; d. Operation of KR feeding system: The KR desulfurization powder silo transports the material to the weighing hopper through the rotary feeder. When the rotation speed of the cross-shaped mixing head reaches 65r / min, 2-3 tons of powder are transported to the desulfurization molten iron tank through the circular chute at a feeding speed of 400kg / min-600kg / min; e. Treat in shallow desulfurization mode, stir for 4-7 minutes, when the speed of the cross-shaped stirring head reaches 85r / min-100r / min, the feeding is finished, the cross-shaped stirring head stops rotating and rises; f. When the cross-shaped stirring head raises the molten iron level by 100-200mm, stop rising and rotate the cross-shaped stirring head to remove slag; g. After 1.5-3 minutes of slag removal, the cross-shaped stirring head continues to rise to the initial position, and KR stirring is completed; h. The molten iron in the desulfurized iron tank is not subjected to slag removal, and is hoisted by a crane to be added to the converter; i. When adding batch materials to the converter head, remove the effective CaO brought by dolomite powder.

[0006] Among them, in the step b, pneumatic conveying is used to transport the dolomite powder from the tank truck to a tank with an effective volume of 80m 3 In the KR desulfurization powder silo.

[0007] Wherein, in the step c, the cross-shaped stirring head is inserted into a molten iron tank containing 86-92 tons of molten iron, and the insertion depth is 1.1m-1.5m.

[0008] The beneficial effects of the present invention are: (1) The present invention makes full use of the functions of the KR pneumatic conveying system and the stirring system to fully utilize the converter's slag-making function using the effective calcium oxide and magnesium oxide in dolomite. Through the linkage between KR and the converter, dolomite powder is mixed into the molten iron and used as a slag-making material for the converter. The resource utilization of effective calcium oxide and magnesium oxide in dolomite powder solid waste in converter slag-making is achieved.

[0009] (2) This method has high solid waste treatment efficiency. For a steel plant with a nominal capacity of 100 tons of converter and an annual steel output of 1.5 million tons, each tank of molten iron can process 2-3 tons of solid waste powder, and the annual dolomite powder solid waste treatment capacity is 30,000-45,000 tons. This process can be used to dispose of a large amount of dolomite powder solid waste, and can achieve a virtuous cycle of dolomite powder within the steel enterprise.

[0010] (3) The present invention solves the problems of large amount of dolomite powder solid waste, dust caused by wind, heating and deterioration when exposed to water and continuous increase in volume when not used for a long time; corrosive effect, adverse to air and water quality, great environmental pressure on enterprises; and occupying land and insufficient storage space for newly generated light-burned dolomite powder.

[0011] (4) The present invention solves a series of problems reflected in the process of solid waste disposal in steel-making converters: bagging and transporting dolomite powder solid waste requires a certain amount of money; a bag of powder solid waste is placed in front of the scrap steel bucket using an overhead crane between the scrap steel spans, and the scrap steel bucket is fed into the converter along with the bag. In the low iron consumption mode, the converter does not have enough heat to dispose of a large amount of solid waste; some dust is generated when the scrap steel bucket is added, and it is difficult for secondary dust removal to completely absorb it, and the addition operation has an adverse effect on the on-site environment; the powder solid waste is easily sucked away by the converter flue, and the utilization rate is low and it has an adverse effect on the dust removal equipment. DETAILED DESCRIPTION

[0012] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0013] Example 1 A method for resource-based disposal of dolomite powder solid waste by KR and converter linkage, comprising the following steps: a. Use tank trucks to load dolomite powder solid waste with a particle size of ≤5mm and transport it to the KR desulfurization station; b. At the KR desulfurization station, dolomite powder is transported from the tank truck to a tank with an effective volume of 80m 3 In the KR desulfurization powder silo; c. Operate the KR stirring system: insert the cross-shaped stirring head into the desulfurized iron tank containing 86 tons of molten iron, and then rotate the cross-shaped stirring head to make the molten iron form a vortex; d. Operation of KR feeding system: The KR desulfurization powder silo transports the material to the weighing hopper through the rotary feeder. When the rotation speed of the cross-shaped mixing head reaches 65r / min, 2 tons of powder is transported to the desulfurization molten iron tank through the circular chute at a feeding speed of 400kg / min; e. Treat in shallow desulfurization mode, stir for 4 minutes, when the speed of the cross-shaped stirring head reaches 85r / min, the feeding is finished, the cross-shaped stirring head stops rotating and rises; f. When the cross-shaped stirring head lifts the molten iron level to 100mm, stop rising and rotate the cross-shaped stirring head to remove slag; g. After 1.5 minutes of slag removal, the cross-shaped stirring head continues to rise to the initial position, and KR stirring is completed; h. The molten iron in the desulfurized iron tank is not subjected to slag removal, and is hoisted by a crane to be added to the converter; i. When adding batch materials to the converter head, remove the effective CaO brought by dolomite powder.

[0014] Among them, in the step b, pneumatic conveying is used to transport the dolomite powder from the tank truck to a tank with an effective volume of 80m 3 In the KR desulfurization powder silo.

[0015] Wherein, in the step c, the cross-shaped stirring head is inserted into a molten iron tank containing 86-92 tons of molten iron, and the insertion depth is 1.1m.

[0016] Example 2 A method for resource-based disposal of dolomite powder solid waste by KR and converter linkage, comprising the following steps: a. Use tank trucks to load dolomite powder solid waste with a particle size of ≤5mm and transport it to the KR desulfurization station; b. At the KR desulfurization station, dolomite powder is transported from the tank truck to a tank with an effective volume of 80m 3 In the KR desulfurization powder silo; c. Operate the KR stirring system: insert the cross-shaped stirring head into the desulfurized iron tank containing 92 tons of molten iron, and then rotate the cross-shaped stirring head to make the molten iron form a vortex; d. Operation of KR feeding system: The KR desulfurization powder bin transports the material to the weighing hopper through the rotary feeder. When the rotation speed of the cross-shaped mixing head reaches 65r / min, 3 tons of powder is transported to the desulfurization molten iron tank through the circular chute at a feeding speed of 600kg / min; e. Treat in shallow desulfurization mode, stir for 7 minutes, when the speed of the cross-shaped stirring head reaches 100r / min, the feeding is finished, the cross-shaped stirring head stops rotating and rises; f. When the cross-shaped stirring head lifts the molten iron surface to 200mm, stop rising and rotate the cross-shaped stirring head to remove slag; g. After 3 minutes of slag removal, the cross-shaped stirring head continues to rise to the initial position, and KR stirring is completed; h. The molten iron in the desulfurized iron tank is not subjected to slag removal, and is hoisted by a crane to be added to the converter; i. When adding batch materials to the converter head, remove the effective CaO brought by dolomite powder.

[0017] Among them, in the step b, pneumatic conveying is used to transport the dolomite powder from the tank truck to a tank with an effective volume of 80m 3 In the KR desulfurization powder silo.

[0018] Wherein, in the step c, the cross-shaped stirring head is inserted into a molten iron tank containing 86-92 tons of molten iron, and the insertion depth is 1.5m.

[0019] Example 3 A method for resource-based disposal of dolomite powder solid waste by KR and converter linkage, comprising the following steps: a. Use a tank truck to load 20 tons of dolomite powder with a particle size of ≤5mm and transport it to the KR desulfurization station; b. At the KR desulfurization station, pneumatic conveying is used to transport powder with a particle size of ≤5mm from the tank truck to the 80m3 KR desulfurization powder silo; c. Operate the KR stirring system: insert the cross-shaped stirring head into the molten iron ladle with 90 tons of molten iron to a depth of 1.2m, and then rotate the stirring head to make the molten iron form a vortex; d. Operation of KR feeding system: the powder bin material is transported to the weighing hopper through the rotary feeder; when the rotating speed of the mixing head reaches 65r / min, 2 tons of powder is transported to the desulfurized iron water tank through the circular chute at a feeding speed of 500kg / min; e. Treat in shallow desulfurization mode, stir for 5 minutes, and when the stirring head speed reaches 90r / min, the feeding is finished, and the stirring head stops rotating and rises; f. When the stirring head lifts the molten iron level to 200mm, stop rising and rotate the stirring head to remove slag; g. After 2 minutes of slag removal, the stirring head continues to rise to the initial position, and KR stirring is completed; h. The molten iron in the molten iron tank is not slag-cut, and the molten iron is hoisted by a crane and added to the converter; i. When adding batch materials to the converter head, remove 800kg of effective CaO brought by dolomite powder.

[0020] Example 4 A method for resource-based disposal of dolomite powder solid waste by KR and converter linkage, comprising the following steps: a. Use a tank truck to load 22 tons of dolomite powder with a particle size of ≤5mm and transport it to the KR desulfurization station; b. At the KR desulfurization station, pneumatic conveying is used to transport powder with a particle size of ≤5mm from the tank truck to the 80m3 KR desulfurization powder silo; c. Operate the KR stirring system: insert the cross-shaped stirring head into the molten iron ladle containing 92 tons of molten iron to a depth of 1.3m, and then rotate the stirring head to make the molten iron form a vortex; d. Operation of KR feeding system: the powder bin material is transported to the weighing hopper through the rotary feeder; when the rotating speed of the mixing head reaches 65r / min, 3 tons of powder is transported to the desulfurized iron water tank through the circular chute at a feeding speed of 600kg / min; e. Treat in shallow desulfurization mode, stir for 6 minutes, and when the stirring head speed reaches 100r / min, the feeding is finished; the stirring head stops rotating and rises; f. When the stirring head lifts the molten iron level to 150mm, stop rising and rotate the stirring head to remove slag; g. After 2.5 minutes of slag removal, the stirring head continues to rise to the initial position, and KR stirring is completed; h. The molten iron in the molten iron tank is not slag-cut, and the molten iron is hoisted by a crane and added to the converter; i. When adding batch materials to the converter head, remove 1200kg of effective CaO brought by dolomite powder.

[0021] It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, and do not constitute a limitation of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the appended claims, or the equivalent forms of such scope and boundaries.

Claims

1. A method for resource-based disposal of dolomite powder solid waste by KR and converter linkage, characterized in that: The following steps are involved: a. Use tank trucks to load dolomite powder solid waste with a particle size of ≤5mm and transport it to the KR desulfurization station; b. At the KR desulfurization station, dolomite powder is transported from the tank truck to a tank with an effective volume of 80m 3 In the KR desulfurization powder silo; c. Operate the KR stirring system: insert the cross-shaped stirring head into the desulfurized iron ladle containing 86-92 tons of molten iron, and then rotate the cross-shaped stirring head to make the molten iron form a vortex; d. Operation of KR feeding system: The KR desulfurization powder silo transports the material to the weighing hopper through the rotary feeder. When the rotation speed of the cross-shaped mixing head reaches 65r / min, 2-3 tons of powder are transported to the desulfurization molten iron tank through the circular chute at a feeding speed of 400kg / min-600kg / min; e. Treat in shallow desulfurization mode, stir for 4-7 minutes, when the speed of the cross-shaped stirring head reaches 85r / min-100r / min, the feeding is finished, the cross-shaped stirring head stops rotating and rises; f. When the cross-shaped stirring head raises the molten iron level by 100-200mm, stop rising and rotate the cross-shaped stirring head to remove slag; g. After 1.5-3 minutes of slag removal, the cross-shaped stirring head continues to rise to the initial position, and KR stirring is completed; h. The molten iron in the desulfurized iron tank is not subjected to slag removal, and is hoisted by a crane to be added to the converter; i. When adding batch materials to the converter head, remove the effective CaO brought by dolomite powder.

2. The method for resource-based disposal of dolomite powder solid waste by KR and converter linkage according to claim 1 is characterized by: In step b, pneumatic conveying is used to transport the dolomite powder from the tank truck to a tank with an effective volume of 80m 3 In the KR desulfurization powder silo.

3. The method for resource-based disposal of dolomite powder solid waste by KR and converter linkage according to claim 1 is characterized by: In the step c, the cross-shaped stirring head is inserted into a molten iron ladle containing 86-92 tons of molten iron, and the insertion depth is 1.1m-1.5m.