Method for prolonging service life of PS nickel converter

Abstract

The invention discloses a method for prolonging the service life of a PS nickel converter, and aims to solve the technical problems that the existing PS nickel converter is limited by the service life of the converter, the overhaul frequency is high, the cost is high, the frequent converter turning-down period is needed, and the continuous and stable operation of production is not facilitated. And meanwhile, the service life of the nickel converter is prolonged by more than 50% by improving the PS nickel converter oven and the blowing parameters and combining the PS nickel converter oven and the blowing parameters.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a method for improving the service life of a PS nickel converter. Background Art

[0002] In modern nickel pyrometallurgy, converters play an important role. After nickel concentrate is oxidized and smelted in flash furnaces, top-blown furnaces, etc., the low-nickel matte produced generally needs to be processed in a PS converter. After iron removal and desulfurization, the high-nickel matte is sent to downstream processes for processing. At present, the PS nickel converter is subject to the influence of furnace life, with frequent maintenance and high costs. It requires frequent furnace downtime, which is not conducive to the continuous and stable operation of production. Therefore, improving the life of the PS nickel converter plays a vital role in reducing the production cost of nickel pyrometallurgy and ensuring the stability of production. Summary of the invention

[0003] The purpose of the present invention is to solve the technical problems that the existing PS nickel converter has a short life, frequent maintenance, high cost, frequent furnace downtime, and is not conducive to continuous production, and to provide a method for improving the life of the PS nickel converter.

[0004] To achieve its purpose, the present invention adopts the following technical solution: The present invention provides a method for improving the service life of a PS nickel converter, comprising the following steps: (1) A protective plate is covered on the upper part of the PS nickel converter guard plate, and a protective baffle is welded between the bottom support of the guard plate and the furnace mouth seat; (2) When constructing the tuyere area of ​​the PS nickel converter, the size of the horizontal gasket used is designed to be larger than 1 / 2 of the distance between the two tuyeres, and the horizontal gaskets are overlapped in sequence. Asbestos rope is used to seal the holes on the side of the horizontal gasket close to the furnace shell; (3) After the PS nickel converter is built, keep the furnace mouth angle at -80°~-100°, and fill the gap between the air eye brick and the horizontal air duct with filler; (4) When the PS nickel converter is heated up, first keep the furnace mouth angle at -80°~-100°, use firewood to bake for 10~14 hours, then turn the furnace body counterclockwise to make the furnace mouth angle 50°~70°, and use natural gas to heat and bake according to the heating curve; (5) In the early stage of PS nickel converter blowing, the amount of hot low-nickel matte added is reduced by 10-20% compared with normal blowing, and low-grade hot low-nickel matte is given priority until the PS nickel converter opening conditions are met; (6) 6~12t of cold material is added in a concentrated manner through bag addition, and the rest of the cold material is added in the bin. In the later stage of blowing, all small-sized cold materials are added in the bin; (7) In the later stage of PS nickel converter blowing, compressed air is used for surface cooling in the area where the local temperature exceeds 200°C in the eye zone, and atomized water is used for surface cooling in the area where the local temperature exceeds 280°C; and the blowing slag type uses high silicon slag with a silicon content of 30~35%.

[0005] Furthermore, in step (1), the surface area of ​​the protection plate is 1 / 2 to 2 / 3 of the guard plate, and the protection plate is connected to the guard plate by bolts; the protection baffle is arranged along the furnace mouth seat, and the angle with the horizontal plane is 40 to 70 degrees.

[0006] Furthermore, in step (3), the filler is a mixture of one or both of brine magnesium powder slurry and phosphoric acid prepared aluminum chromium mortar; the brine magnesium powder slurry is prepared by preparing magnesium chromium powder and brine, and the phosphoric acid prepared aluminum chromium mortar is prepared by preparing magnesium chromium powder and chromium slag powder and phosphoric acid; the magnesium chromium powder is crushed from semi-recombined magnesium chromium bricks, and the powder particle size is required to be greater than 90% at -200 mesh.

[0007] Furthermore, in step (3), the brine magnesium powder slurry is prepared by mixing magnesium chromium powder and brine at a mixing ratio of 5-6:1, and the mass ratio of magnesium chromium powder, chromium slag powder and phosphoric acid in the phosphoric acid mixed aluminum chromium slurry is 15-18:2-3:1-2.

[0008] Furthermore, in step (3), the brine is a magnesium chloride aqueous solution with a concentration of 15-25%.

[0009] Furthermore, in step (4), the temperature rise curve is as follows: the temperature of the space in the furnace is raised to 400-410°C in 18-22 hours and maintained at a constant temperature for 8-10 hours; the temperature is raised to 800-810°C in another 18-22 hours and maintained at a constant temperature for 10-14 hours; and the temperature is finally raised to 1000-1010°C in 8-10 hours and maintained at a constant temperature for 4-8 hours.

[0010] Furthermore, the initial stage of blowing is 200 to 300 blowing furnaces.

[0011] Furthermore, the later stage of blowing is blowing furnaces greater than 350 times.

[0012] Furthermore, in step (5), the grade of the hot low nickel matte is 41-46% (Ni+Cu), and the grade of the low-grade hot low nickel matte is 29-32% (Ni+Cu).

[0013] Furthermore, in step (7), the compressed air and atomized water are transported through a cooling spray gun, and the cooling spray gun is a double-layer sleeve structure, with compressed air passing through the middle and water passing through the outside. By adopting the above technical solution, the beneficial effects of the present invention are: Under the premise of maintaining the original blowing system, the method of the present invention sets a protective plate, a guard plate and a protective baffle to protect the furnace shell from being burned, reduce leakage in the tuyere area, and reduce the frequency of melt splashing. At the same time, by improving the PS nickel converter baking furnace and blowing parameters, the two are combined to increase the life of the nickel converter by more than 50%. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the positional relationship of each component and the angle of the furnace opening in the method of the present invention; Figure numerals: 1 - furnace shell; 2 - furnace mouth; 3 - protection plate; 4 - guard plate; 5 - protection baffle; 6 - horizontal air duct. DETAILED DESCRIPTION

[0015] The present invention is described in detail below with reference to the accompanying drawings.

[0016] Reference Figure 1 The present invention provides a method for improving the life of a PS nickel converter, and the specific operation is shown in the following embodiments.

[0017] Example 1 In this embodiment, the surface area of ​​the protection plate 3 is 1 / 2 of the protection plate 4, and is connected to the protection plate 4 by bolts; the protection baffle 5 is arranged along the furnace mouth seat and has an angle of 50° with the horizontal plane.

[0018] Specifically, the present embodiment provides a method for improving the life of a PS nickel converter. First, a protective plate 3 is covered on the upper part of the PS nickel converter guard plate 4, and a protective baffle 5 is welded between the bottom support of the guard plate 4 and the furnace mouth seat; when the eye area is built, the size of the horizontal gasket used is greater than 1 / 2 of the distance between the two eyelets to ensure that the horizontal gasket can completely cover the surrounding area of ​​the eyelet, and each horizontal gasket is overlapped in sequence, and the horizontal gasket is close to the furnace shell 1. The hole is sealed with asbestos rope to ensure that the filler does not leak from the eye area; after the masonry is completed, the furnace mouth angle is maintained at -90°, and the gap between the eyelet brick and the horizontal air duct 6 is filled with brine magnesium powder slurry and phosphoric acid-modulated aluminum-chromium mortar in a mass ratio of 1:1. Among them, the brine magnesium powder slurry is made of magnesium chromium powder and brine, the modulation ratio is 6:1, and the brine concentration is 20%. The mass ratio of magnesium chromium powder, chromium slag powder and phosphoric acid in the phosphoric acid-modulated aluminum-chromium mortar is 16:2:1, and it is stirred and mixed evenly and placed for 24 hours.

[0019] When the PS nickel converter is heated up, first keep the angle of furnace mouth 2 at -90°, use firewood to bake for 12 hours, then rotate the furnace body counterclockwise to make the angle of furnace mouth 2 60°, use the natural gas heating curve, heat up to 400°C in 20 hours, and keep the temperature constant for 9 hours; then heat up to 800°C in 18 hours, and keep the temperature constant for 10 hours; finally heat up to 1000°C in 8 hours, and keep the temperature constant for 4 hours.

[0020] During the production of the PS nickel converter, 10% less hot low-nickel matte was added in the first 250 batches after the overhaul than in normal blowing. 29~32% (Ni+Cu) low-grade hot low-nickel matte was given priority. It was expected that the melt could submerge the air eye when the furnace body was transferred to the blowing position (0°). Blowing was turned on and 6t of cold material was added in a concentrated manner through ladle addition, and the remaining cold material was added in bins. All of the cold material was added in bins in the later stage of blowing.

[0021] For blowing furnaces with more than 350 times of operation, compressed air shall be used for surface cooling in the area where the local temperature of the eye zone exceeds 200°C, and atomized water shall be used for surface cooling in the area where the local temperature of the eye zone exceeds 280°C; and the blowing slag shall be high-silicon slag with a silicon content of 32%.

[0022] Through the above methods, the number of overhauls of the PS nickel converter increased from 370 to 490, and the overhaul cycle increased from 4 to 5 times; the overall furnace life increased by 59%.

[0023] Example 2 In this embodiment, the surface area of ​​the protection plate 3 is 1 / 2 of the protection plate 4, and is connected to the protection plate 4 by bolts; the protection baffle 5 is arranged along the furnace mouth seat and has an angle of 60° with the horizontal plane.

[0024] Specifically, the present embodiment provides a method for improving the service life of a PS nickel converter. First, a protective plate 3 is covered on the upper part of the PS nickel converter guard plate 4, and a protective baffle 5 is welded between the bottom support of the guard plate 4 and the furnace mouth seat; when the eye area is built, the size of the horizontal gasket used is greater than 1 / 2 of the distance between the two eyelets to ensure that the horizontal gasket can completely cover the area around the eyelet, and each horizontal gasket is overlapped in sequence, and the horizontal gasket is sealed with asbestos rope on the side of the furnace shell 1 to ensure that the filler does not leak from the eye area; after the masonry is completed, the furnace mouth angle is maintained at -95°, and the gap between the eyelet brick and the horizontal air duct 6 is filled with aluminum-chromium mortar prepared with phosphoric acid. The brine concentration is 22%. The mass ratio of magnesium-chromium powder, chromium slag powder and phosphoric acid in the phosphoric acid prepared aluminum-chromium mortar is 16:3:1.5, and it is stirred and mixed evenly and placed for 24 hours.

[0025] When the PS nickel converter is heated up, first keep the angle of furnace mouth 2 at -95°, use firewood to bake for 13 hours, then rotate the furnace body counterclockwise to make the angle of furnace mouth 2 65°, use the natural gas heating curve, heat up to 405°C in 21 hours, and keep the temperature constant for 9 hours; then heat up to 805°C in 19 hours, and keep the temperature constant for 10 hours; finally heat up to 1050°C in 9 hours, and keep the temperature constant for 4 hours.

[0026] During the production of the PS nickel converter, 10% less hot low-nickel matte was added in the first 280 batches after the overhaul than in normal blowing. 29~32% (Ni+Cu) low-grade hot low-nickel matte was given priority. It was expected that the melt could submerge the tuyere when the furnace body was transferred to the blowing position (0°). Blowing was turned on and 9t of cold material was added in a concentrated manner through ladle addition. The remaining cold material was added in bins, and all of it was added in bins in the later stage of blowing.

[0027] For blowing furnaces with more than 350 times of operation, compressed air shall be used for surface cooling in the area where the local temperature of the eye zone exceeds 200°C, and atomized water shall be used for surface cooling in the area where the local temperature of the eye zone exceeds 280°C; and the blowing slag shall be high-silicon slag with a silicon content of 32%.

[0028] Through the above methods, the number of PS nickel converter overhauls increased from 370 to 530, and the overhaul cycle increased from 4 to 5 times; the overall furnace life increased by 72%.

[0029] Example 3 In this embodiment, the surface area of ​​the protection plate 3 is 2 / 3 of the protection plate 4, and is connected to the protection plate 4 by bolts; the protection baffle 5 is arranged along the furnace mouth seat and has an angle of 60° with the horizontal plane.

[0030] Specifically, the present embodiment provides a method for improving the service life of a PS nickel converter. First, a protective plate 3 is covered on the upper part of the PS nickel converter guard plate 4, and a protective baffle 5 is welded between the bottom support of the guard plate 4 and the furnace mouth seat; when the eye area is built, the size of the horizontal gasket used is greater than 1 / 2 of the distance between the two eyelets to ensure that the horizontal gasket can completely cover the area around the eyelet, and each horizontal gasket is overlapped in sequence, and the horizontal gasket is sealed with asbestos rope on the side of the furnace shell 1 to ensure that the filler does not leak from the eye area; after the masonry is completed, the furnace mouth angle is maintained at -90°, and the gap between the eyelet brick and the horizontal air duct 6 is filled with aluminum-chromium mortar prepared with phosphoric acid. The modulation ratio of magnesium-chromium powder, chromium slag powder and phosphoric acid in the phosphoric acid prepared aluminum-chromium mortar is 15:2:1, and it is stirred and mixed evenly and then placed for 24 hours.

[0031] When the PS nickel converter is heated up, first keep the angle of furnace mouth 2 at -90°, use firewood to bake for 14 hours, then rotate the furnace body counterclockwise to make the angle of furnace mouth 2 60°, use the natural gas heating curve, heat up to 400°C in 22 hours, keep the temperature constant for 10 hours; then heat up to 800°C in 22 hours, keep the temperature constant for 14 hours; finally heat up to 1000°C in 10 hours, keep the temperature constant for 8 hours.

[0032] During the production of the PS nickel converter, 15% less hot low-nickel matte was added in the first 230 batches after the overhaul than in normal blowing. 29~32% (Ni+Cu) low-grade hot low-nickel matte was given priority. It was expected that the melt could submerge the air eye when the furnace body was transferred to the blowing position (0°). Blowing was turned on, and 8t of cold material was added in a concentrated manner by ladle addition. The remaining cold material was added in bins, and all of it was added in bins in the later stage of blowing.

[0033] For blowing furnaces with more than 350 times of operation, compressed air shall be used for surface cooling in the area where the local temperature of the eye zone exceeds 200°C, and atomized water shall be used for surface cooling in the area where the local temperature of the eye zone exceeds 280°C; and the blowing slag shall be high-silicon slag with a silicon content of 35%.

[0034] Through the above methods, the number of overhauls of the PS nickel converter increased from 370 to 580, and the overhaul cycle increased from 4 to 5; the overall furnace life increased by 88%.

Claims

1. A method for improving the life of a PS nickel converter, characterized in that: The following steps are involved: (1) A protective plate (3) is covered on the upper part of the PS nickel converter guard plate (4), and a protective baffle (5) is welded between the bottom support of the guard plate (4) and the furnace mouth seat; (2) When constructing the tuyere area of ​​the PS nickel converter, the size of the horizontal gasket used is designed to be larger than 1 / 2 of the distance between the two tuyeres, and the horizontal gaskets are overlapped in sequence. Asbestos rope is used to seal the holes on the side of the horizontal gasket close to the furnace shell (1); (3) After the PS nickel converter is built, the furnace mouth angle is maintained at -80°~-100°, and the gap between the air eye brick and the horizontal air duct (6) is filled with filler; (4) When the PS nickel converter is heated, first keep the angle of the furnace mouth (2) at -80°~-100°, use firewood to bake for 10~14 hours, then rotate the furnace body counterclockwise to make the angle of the furnace mouth (2) 50°~70°, and use natural gas to heat and bake according to the heating curve; (5) In the early stage of PS nickel converter blowing, the amount of hot low-nickel matte added is reduced by 10-20% compared with normal blowing, and low-grade hot low-nickel matte is given priority until the PS nickel converter opening conditions are met; (6) 6~12t of cold material is added in a concentrated manner through bag addition, and the rest of the cold material is added in the bin. In the later stage of blowing, all small-sized cold materials are added in the bin; (7) In the later stage of PS nickel converter blowing, compressed air is used for surface cooling in the area where the local temperature exceeds 200°C in the eye zone, and atomized water is used for surface cooling in the area where the local temperature exceeds 280°C; and the blowing slag type uses high silicon slag with a silicon content of 30~35%.

2. A method for improving the life of a PS nickel converter as claimed in claim 1, characterized in that: In step (1), the surface area of ​​the protection plate (3) is 1 / 2 to 2 / 3 of the protection plate (4), and the protection plate (3) is connected to the protection plate (4) by bolts; the protection baffle (5) is arranged along the furnace mouth seat, and the angle with the horizontal plane is 40 to 70 degrees.

3. A method for improving the life of a PS nickel converter as claimed in claim 2, characterized in that: In step (3), the filler is a mixture of one or both of brine magnesium powder slurry and phosphoric acid-modulated aluminum-chromium mortar; the brine magnesium powder slurry is prepared by mixing magnesium-chromium powder with brine at a mixing ratio of 5 to 6:1, and the phosphoric acid-modulated aluminum-chromium mortar is prepared by mixing magnesium-chromium powder and chromium slag powder with phosphoric acid; the magnesium-chromium powder is crushed from semi-recombined magnesium-chromium bricks, and the powder particle size is required to be higher than 90% at -200 mesh.

4. A method for improving the life of a PS nickel converter as claimed in claim 3, characterized in that: In step (3), the mass ratio of magnesium chromium powder, chromium slag powder and phosphoric acid in the phosphoric acid-prepared aluminum chromium slurry is 15-18:2-3:1-2.

5. A method for improving the life of a PS nickel converter as claimed in claim 4, characterized in that: In step (3), the brine is a magnesium chloride aqueous solution with a concentration of 15-25%.

6. A method for improving the life of a PS nickel converter as described in any one of claims 1 to 5, characterized in that: In step (4), the temperature rise curve is as follows: the temperature of the space in the furnace is raised to 400-410°C in 18-22 hours and kept at a constant temperature for 8-10 hours; the temperature is raised to 800-810°C in another 18-22 hours and kept at a constant temperature for 10-14 hours; and the temperature is finally raised to 1000-1010°C in 8-10 hours and kept at a constant temperature for 4-8 hours.

7. A method for improving the life of a PS nickel converter as described in any one of claims 1 to 5, characterized in that: The initial blowing stage is 200 to 300 blowing furnaces.

8. A method for improving the life of a PS nickel converter as described in any one of claims 1 to 5, characterized in that: The late stage of blowing is when the blowing furnace times are greater than 350 times.

9. A method for improving the life of a PS nickel converter as described in any one of claims 1 to 5, characterized in that: In step (5), the grade of the hot low nickel matte is 41-46% (Ni+Cu), and the grade of the low-grade hot low nickel matte is 29-32% (Ni+Cu).

10. A method for improving the life of a PS nickel converter as claimed in any one of claims 1 to 5, characterized in that: In step (7), the compressed air and atomized water are transported through a cooling spray gun, and the cooling spray gun is a double-layer sleeve structure, with compressed air passing through the middle and water passing through the outside.

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