A method for improving the permeability of a sintering thick layer

Abstract

The present application relates to the technical field of steel metallurgy, and particularly relates to a method for improving the permeability of a sintering thick material layer, which comprises: primary bottoming: screening finished product ore and laying the screened finished product ore on a sintering trolley; secondary bottoming: distributing n rows of feeding pipes along the transverse direction of the trolley at equal intervals, distributing m feeding pipes in each row at equal intervals, detecting and imaging the sintering machine tail section by using a sintering machine tail infrared thermal imager, performing image processing by using machine vision to horizontally and vertically grid the sintering machine tail section, dividing the transverse direction into m regions, extracting a red fire region, and obtaining the average thickness of the red fire layer; adjusting the discharging amount speed of the feeding pipe according to the average thickness, and performing secondary bottoming by using the feeding pipe; laying sintering mixture on the basis of the secondary bottoming, and performing ignition sintering. The discharging amount speed of the feeding pipe is adjusted in combination with the shape of the red fire layer of the sintering machine tail section, the distribution of the secondary bottoming is optimized, and the overall material layer permeability of the sintering trolley is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steel metallurgy, in particular to a method for improving the permeability of a thick sintering material layer. BACKGROUND

[0002] In the sintering process, the permeability of the sintering mixture is a key production parameter. The permeability has a very important influence on the sintering yield and quality. When the permeability is good, the vertical speed of the sintering material layer is accelerated, thereby increasing the yield; on the contrary, poor permeability will slow down the vertical speed of the sintering material layer, which will accordingly reduce the yield per unit time. Moreover, good permeability helps to avoid the occurrence of overburning, thereby fully guaranteeing the quality of the sintered product. As can be seen, ensuring that the permeability of the mixture during sintering is within an appropriate range plays a crucial role in improving the quality of the sinter.

[0003] At present, a loosening device is generally used in the sintering production process to improve the permeability of the sintering material layer. However, with the gradual increase in the thickness of the sintering material layer, increasing the number of loosening rods in order to further improve the permeability brings a series of new problems. The gaps between the loosening rods decrease due to the increase in the number of the rods, which makes the larger pieces of sintering mixture easily get stuck between the loosening rods when passing through, and also increases the difficulty of the operators in cleaning the accumulated material of the loosening rods, and can also cause adverse phenomena such as draw grooves and unevenness on the material surface, ultimately resulting in uneven effective air volume through the material layer.

[0004] When this situation is reflected in the cross section of the sintering machine tail, it can be found that the red ore layer of the cross section has a "flower face" phenomenon, i.e., a part of the area is not burned through and contains raw material, while another part of the area is overburned, which undoubtedly seriously affects the stability of the sinter production quality. Especially in the case of a large sintering machine with a material layer thickness generally reaching 750 mm or even 1000 mm in some cases, and a large proportion of concentrate sintering, the existing loosening device is difficult to meet the requirements of the permeability of the thick material layer production. SUMMARY

[0005] In order to overcome the defects of the prior art, the technical problem solved by the present application is to provide a method for improving the permeability of a thick sintering material layer. The method comprises the following steps: distributing n rows of feeding pipes along the transverse direction of the sintering machine between the bottom material leveling plate and the nine-roller distributor, distributing m feeding pipes in each row at equal intervals, and adjusting the discharging speed of the feeding pipes in combination with the shape of the red fire layer of the cross section of the sintering machine tail, optimizing the distribution of the secondary bottom material, and improving the permeability of the overall material layer of the sintering trolley.

[0006] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions:

[0007] A method for improving the permeability of a thick sintering material layer, characterized in that it comprises the following steps:

[0008] 1) Primary paving: the screened finished ore is paved on the sintering trolley, and is leveled;

[0009] 2) Secondary paving: on the sintering machine, n rows of feeding pipes are distributed equidistantly along the transverse direction of the trolley, and m feeding pipes are distributed equidistantly in each row; the sintering machine tail section is detected and imaged by the infrared thermal imager at the sintering machine tail, and the sintering machine tail section is transversely gridded and longitudinally gridded through image processing by machine vision; the transverse direction is divided into m regions, and the regions are numbered; i represents a certain region, and i takes the value range of 1, 2, 3…m; each region corresponds to the position of a feeding pipe; the image processing of the red fire region is extracted; according to the temperature distribution shape of the red fire layer of the sintering machine tail section, the red fire layer temperature characteristic value is extracted, the lower edge curve function f1 of the red fire layer and the upper edge curve function f2 of the red fire layer are obtained, and the average thickness h of the red fire layer in each region grid at the tail of the sintering trolley is obtained. f2-f1; according to the average thickness h in the region grid, the feeding pipe discharge rate is adjusted; the secondary paving is performed on the primary paving by the feeding pipe;

[0010] 3) Paving of sintering mixture: on the basis of secondary paving, the sintering mixture is paved and leveled, and ignition sintering is performed.

[0011] If 3 trolleys or more continuously appear h<50mm on the sintering machine in the i-th region grid, or 3 h<50mm appear alternately at intervals of 6 trolleys, the discharge rate φ of each row of the i-th feeding pipe is 0;

[0012] If 3 trolleys or more continuously appear 50mm≤h≤100mm on the sintering machine in the i-th region grid, or 3 50mm≤h≤100mm appear alternately at intervals of 6 trolleys, the discharge rate φ of each row of the i-th feeding pipe is 30±3 kg / h;

[0013] If 2 trolleys or more continuously appear h>100mm on the sintering machine in the i-th region grid, or 2 h>100mm appear alternately at intervals of 4 trolleys, the discharge rate φ of each row of the i-th feeding pipe is 50±5 kg / h.

[0014] In the step 1), the finished ore particle size is 10-20 mm, and the primary paving thickness ranges from 10 to 30 mm.

[0015] In the step 1), the finished ore particle size is 10-20 mm, and the primary paving thickness ranges from 10 to 30 mm.

[0016] In the step 2), 1≤n≤3, and 10≤m≤30.

[0017] In the step 3), the ignition sintering conditions are as follows: the ignition temperature range is 950-1050 DEG C, the air draft negative pressure range is 8000-10500 Pa, and the ignition time range is 1.5-2 min.

[0018] In the step 2), the feeding pipe is arranged between the bottom material scraping plate of the sintering machine and the nine-roller distributor.

[0019] Compared with the prior art, the present application has the following beneficial effects:

[0020] In the present application, n rows of feeding pipes are distributed equidistantly along the transverse direction of the sintering pallet, and m feeding pipes are distributed equidistantly in each row, and the average thickness of the red fire layer in each area grid at the tail of the sintering pallet is obtained according to the shape of the red fire layer at the tail section of the sintering machine, and the feeding speed of the feeding pipe is adjusted according to the average thickness, so that the accumulation thickness and distribution of the secondary bottom material can be changed, that is, the material layer in the area can be appropriately thinned by reducing the feeding speed, and the porosity of the material layer is increased, so that the air permeability is improved; on the contrary, if the air permeability is too good, the feeding speed can be appropriately increased to thicken the material layer, so that the gas has a more suitable flow resistance in the material layer, and the air permeability is optimized. BRIEF DESCRIPTION OF DRAWINGS

[0021] The accompanying drawings, which form a part of this application, are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification. The illustrations are shown to explain the present application and are not intended to limit the present application unduly.

[0022] Figure 1 is a schematic diagram of the feeding pipe arrangement of the present application.

[0023] Figure 2 is a flow chart of the present application.

[0024] BRIEF DESCRIPTION OF DRAWINGS

[0025] In the drawings: 1-pallet; 2-nine-roller distributor; 3-bottom material scraping plate; 4-feeding pipe; 5-infrared thermal imager. DETAILED DESCRIPTION

[0026] The specific embodiment of the present application is further described as follows:

[0027] Example 1:

[0028] A sintering plant with a 265m 2 The present application is illustrated by taking a sintering machine as an example.

[0029] Table 1 Basic parameters of the sintering machine

[0030] Sintering machine area / m 2 ]]> Trolley width / mm Layer thickness / mm 265 3500 750

[0031] As Figures 1 to 2 Figures 1 to 2As shown, a method for improving the permeability of a sintering thick layer includes the following steps:

[0032] 1) First bottoming: the screened finished product with a particle size of 10-20 mm is laid on the sintering trolley through the bunker and the distributor, and the first bottoming is leveled by the bottoming leveling plate, so that it is flat, and the thickness of the first bottoming ranges from 10 mm;

[0033] 2) Second bottoming: n rows of feeding pipes 4 are distributed equidistantly along the transverse direction of the trolley 1 between the bottoming leveling plate 3 of the sintering machine and the nine-roller distributor 2, and each row has m feeding pipes 4, n = 1, m = 10; the sintering machine tail section is detected and imaged by the infrared thermal imager 5 at the sintering machine tail, and the dark color represents the sinter that has cooled to a certain temperature, and the lower red color represents the sinter that has not cooled well (i.e., the red fire layer described in the present application). The image is transmitted to the image processing interface, and the sintering machine tail section is transversely gridded and longitudinally gridded by image processing through machine vision, the transverse direction is divided into 10 regions, and the regions are numbered, and i represents a certain region, i takes a value ranging from 1, 2, 3…10. Each region corresponds to the position of a feeding pipe 4, the image processing of the red fire region is extracted, the temperature characteristic value of the red fire layer is extracted according to the temperature distribution shape of the red fire layer of the sintering machine tail section, the lower edge curve function f1 of the red fire layer and the upper edge curve function f2 of the red fire layer are obtained, f2 is a function of the upper 500℃ isotherm of the red fire layer corresponding to the height of the vertical coordinate f2 from the bottom of the trolley with the midpoint of the transverse width of the sintering trolley as the origin and the width as the horizontal coordinate x; f1 is also a function of the lower 700℃ isotherm of the red fire layer corresponding to the height of the vertical coordinate f1 from the bottom of the trolley with the midpoint of the transverse width of the sintering trolley as the origin and the width as the horizontal coordinate x; the average thickness of the red fire layer in each region grid at the tail of the sintering trolley is h = f2-f1; the feeding amount of the feeding pipe is adjusted according to the average thickness h in the region grid; the second bottoming is performed on the first bottoming by the feeding pipe;

[0034] 3) Laying sintering mixture: lay the sintering mixture on the basis of the second bottoming and level it, and ignite and sinter; the ignition and sintering conditions are: the ignition temperature is 950℃, the exhaust negative pressure is 8500Pa, and the ignition time is 1.5min.

[0035] In the application process, if the average thickness of the red fire layer in the third region grid continuously appears h 3,1 =43.45mm、h 3,2 =33.16mm、h 3,3 =43.45mm on 3 or more trolleys of the sintering machine, or h 3,1 =41.26mm、h 3,2 =51.38mm、h 3,3= 33.68 mm, h 3,4 = 56.87 mm, h 3,5 = 23.76 mm, h 3,6 = 63.45 mm, corresponding to the speed φ of the third downcomer of 0; (wherein h 3,1 , h 3,2 , h 3,3 represents the average thickness of the red layer of the three consecutive trolleys in the third area grid, and the following is similar).

[0036] If the average thickness of the red layer in the fifth area grid appears continuously on the sintering machine for 3 trolleys or more h 5,1 = 81.36 mm, h 5,2 = 72.45 mm, h 5,3 = 91.05 mm, or h 5,1 = 41.26 mm, h 5,2 = 51.38 mm, h 5,3 = 33.68 mm, h 5,4 = 56.87 mm, h 5,5 = 23.76 mm, h 5,6 = 63.45 mm, corresponding to the speed φ of the fifth downcomer of 31 kg / h;

[0037] If the average thickness of the red layer in the sixth area grid appears continuously on the sintering machine for 2 trolleys or more h 6,1 = 121.44 mm, h 6,2 = 109.36 mm, or h 6,1 = 96.66 mm, h 6,2 = 129.38 mm, h 6,3 = 91.48 mm, h 6,4 = 152.26 mm, corresponding to the speed φ of the sixth downcomer of 55 kg / h.

[0038] The vertical speed of the sintering machine in this embodiment is increased from 24.44 mm / min to 28.66 mm / min, and the utilization coefficient is increased from 1.28 t / (m 2 ·h) to 1.38 t / (m 2 ·h), an increase of 8 percentage points; the sinter drum strength is increased from 78.76% to 80.03%; and the screening index is reduced from 6.80% to 6.53%.

[0039] Example 2:

[0040] Taking the application of a 360 m 2 sintering machine in a certain sintering plant as an example.

[0041] Table 2 sintering machine basic parameters

[0042]

[0043] A method for improving the permeability of a sintering thick layer, comprising the following steps:

[0044] 1) First bottoming: the screened finished product ore with a particle size of 10-20 mm is laid on the sintering trolley through the bunker and the distributor, and the first bottoming is leveled by the bottoming leveling plate, so that it is flat, and the thickness of the first bottoming ranges from 15 mm;

[0045] 2) Second bottoming: n rows of feeding pipes are distributed at equal intervals along the transverse direction of the trolley between the bottoming leveling plate of the sintering machine and the nine-roller distributor, and each row has m feeding pipes, n=2, m=20; the sintering machine tail section is detected and imaged by the infrared thermal imager at the sintering machine tail, the image is transmitted to the image processing interface, the sintering machine tail section is horizontally and vertically gridded by image processing through machine vision, the horizontal direction is divided into 20 areas, and the areas are numbered, and i represents a certain area, i takes a value ranging from 1, 2, 3…20. Each area corresponds to the position of a feeding pipe, the image processing of the red fire area is extracted, the temperature characteristic value of the red fire layer is extracted according to the temperature distribution shape of the red fire layer of the sintering machine tail section, the lower edge curve function f1 of the red fire layer and the upper edge curve function f2 of the red fire layer are obtained, f2 is a function of the midpoint of the transverse width of the sintering trolley as the origin, the width as the horizontal coordinate x, and the height of the 500℃ isotherm of the upper layer of the red fire layer corresponding to the distance from the bottom of the trolley as the vertical coordinate f2; f1 is also a function of the midpoint of the transverse width of the sintering trolley as the origin, the width as the horizontal coordinate x, and the height of the 700℃ isotherm of the lower layer of the red fire layer corresponding to the distance from the bottom of the trolley as the vertical coordinate f1; the average thickness of the red fire layer in each area grid at the tail of the sintering trolley is h=f2-f1; the feeding amount of the feeding pipe is adjusted according to the average thickness h in the area grid; the second bottoming is performed on the first bottoming by the feeding pipe;

[0046] 3) Laying sintering mixture: laying sintering mixture on the basis of the second bottoming and leveling, and igniting and sintering; the ignition and sintering conditions are: the ignition temperature is 1047.9℃, the exhaust negative pressure is 8980Pa, and the ignition time is 1.67min.

[0047] In the application process, if the average thickness of the red fire layer in the 7th area grid appears h 7,1 =24.35mm, h 7,2 =13.56mm, h 7,3 =23.65mm on 3 or more trolleys of the sintering machine in succession or h 7,1 =11.27mm, h7,2 = 61.38 mm, h 7,3 = 23.69 mm, h 7,4 = 66.18 mm, h 7,5 = 43.68 mm, h 7,6 = 73.45 mm, the corresponding φ of the 7th downcomer in the 2nd row is 0;

[0048] If the average thickness of the red flame layer in the 9th grid appears continuously for 3 or more cars on the sintering machine h 9,1 = 90.48 mm, h 9,2 = 88.46 mm, h 9,3 = 99.95 mm, or h 9,1 = 31.36 mm, h 9,2 = 72.39 mm, h 9,3 = 43.98 mm, h 9,4 = 81.67 mm, h 9,5 = 33.31 mm, h 9,6 = 53.55 mm, the corresponding φ of the 9th downcomer in the 2nd row is 33 kg / h;

[0049] If the average thickness of the red flame layer in the 13th grid appears continuously for 2 or more cars on the sintering machine h 13,1 = 106.54 mm, h 13,2 = 119.46 mm, or h 13,1 = 88.66 mm, h 13,2 = 141.18 mm, h 13,3 = 75.59 mm, h 13,4 = 132.33 mm, the corresponding φ of the 13th downcomer in the 2nd row is 53 kg / h.

[0050] The vertical speed of the sintering machine in this embodiment is increased from 25.46 mm / min to 29.16 mm / min, the utilization coefficient is increased from 1.29 t / (m 2 ·h) to 1.41 t / (m 2 ·h), an increase of 9 percentage points; the sinter drum strength is increased from 79.76% to 81.03%; the screening index is reduced from 5.90% to 5.73%.

[0051] Example 3:

[0052] Take a 405 m 2 sintering machine as an example.

[0053] Table 3 Basic parameters of sintering machine

[0054]

[0055] A method for improving the permeability of a sintering thick layer, comprising the following steps:

[0056] 1) First bottoming material: the screened finished product with a particle size of 10-20 mm is laid on the sintering trolley through the bunker and the distributor, and the first bottoming material is leveled by the bottoming material leveling plate, so that it is flat, and the thickness of the first bottoming material ranges from 15 mm;

[0057] 2) Second bottoming material: n rows of feeding pipes are distributed at equal intervals along the transverse direction of the trolley between the bottoming material leveling plate of the sintering machine and the nine-roller distributor, and each row has m feeding pipes, n=3, m=30; the sintering machine tail section is detected and imaged by the infrared thermal imager at the sintering machine tail, the image is transmitted to the image processing interface, the image processing is performed by machine vision to horizontally and vertically grid the sintering machine tail section, the horizontal direction is divided into 30 areas, and the areas are numbered, and i represents a certain area, i takes a value ranging from 1, 2, 3…30. Each area corresponds to the position of a feeding pipe, the image processing of the red fire area is extracted, the temperature characteristic value of the red fire layer is extracted according to the temperature distribution shape of the red fire layer of the sintering machine tail section, the lower edge curve function f1 of the red fire layer and the upper edge curve function f2 of the red fire layer are obtained, f2 is a function of the midpoint of the transverse width of the sintering trolley as the origin, the width as the horizontal coordinate x, and the height of the 500℃ isotherm of the upper layer of the red fire layer corresponding to the distance from the bottom of the trolley as the vertical coordinate f2; f1 is also a function of the midpoint of the transverse width of the sintering trolley as the origin, the width as the horizontal coordinate x, and the height of the 700℃ isotherm of the lower layer of the red fire layer corresponding to the distance from the bottom of the trolley as the vertical coordinate f1; the average thickness of the red fire layer in each area grid at the tail of the sintering trolley is h=f2-f1; the feeding amount of the feeding pipe is adjusted according to the average thickness h in the area grid; the second bottoming material is laid on the first bottoming material through the feeding pipe;

[0058] 3) Laying sintering mixture: laying sintering mixture on the basis of the second bottoming material and leveling, igniting and sintering; the ignition sintering conditions are: the ignition temperature is 1046.8℃, the exhaust negative pressure is 9680Pa, and the ignition time is 1.97min.

[0059] In the application process, if the average thickness of the red fire layer in the 9th area grid continuously appears h 9,1 =33.45mm, h 9,2 =24.66mm, h 9,3 =43.66mm on 3 trolleys or more of the sintering machine, or h 9,1 =41.28mm, h 9,2 =67.39mm, h 9,3= 34.66 mm, h 9,4 = 56.17 mm, h 9,5 = 34.55 mm, h 9,6 = 63.46 mm, the corresponding φ of the 9th pipe in the 3rd row is 0;

[0060] If the average thickness of the red flame layer in the 12th grid appears continuously for 3 or more cars on the sintering machine, h 12,1 = 76.49 mm, h 12,2 = 78.56 mm, h 12,3 = 89.45 mm, or h 12,1 = 43.37 mm, h 12,2 = 62.49 mm, h 12,3 = 33.88 mm, h 12,4 = 71.27 mm, h 12,5 = 43.36 mm, h 12,6 = 73.56 mm, the corresponding φ of the 12th pipe in the 3rd row is 32 kg / h;

[0061] If the average thickness of the red flame layer in the 16th grid appears continuously for 2 or more cars on the sintering machine, h 16,1 = 123.55 mm, h 16,2 = 149.16 mm, or h 16,1 = 58.76 mm, h 16,2 = 131.56 mm, h 16,3 = 65.59 mm, h 16,4 = 102.53 mm, the corresponding φ of the 16th pipe in the 3rd row is 51 kg / h.

[0062] The vertical speed of the sintering machine in this embodiment is increased from 27.46 mm / min to 31.16 mm / min, the utilization coefficient is increased from 1.31 t / (m 2 ·h) to 1.46 t / (m 2 ·h), an increase of 11.4 percentage points; the sinter drum strength is increased from 79.76% to 82.03%; the screening index is reduced from 5.40% to 5.03%.

[0063] The preferred embodiments of the present application are described in detail above with reference to the drawings, but the present application is not limited to the specific details in the above-described embodiments, and various simple modifications can be made to the technical solutions of the present application within the technical concept of the present application, and these simple modifications all belong to the protection scope of the present application. In addition, it should be noted that, in the above-described specific embodiments, various specific technical features can be combined in any appropriate manner without contradiction, and in order to avoid unnecessary repetition, the present application will not further describe various possible combination manners. In addition, various different embodiments of the present application can also be combined in any manner, as long as it does not deviate from the idea of the present application, and it should also be considered as disclosed by the present application.

Claims

1. A method of improving the permeability of a sintering thick layer, characterized in that, It comprises the following steps: 1) Primary bottoming: the screened finished ore is laid on the sintering trolley and leveled; 2) Secondary bottoming: on the sintering machine, n rows of feeding pipes are distributed at equal intervals along the transverse direction of the trolley, and m feeding pipes are distributed at equal intervals in each row. The cross section of the sintering machine tail is detected and imaged by the infrared thermal imager at the sintering machine tail, and the cross section of the sintering machine tail is horizontally and vertically gridded by image processing by machine vision. The transverse direction is divided into m regions, and the regions are numbered. Let i represent a region, and i takes the value of 1, 2, 3…m; each region corresponds to the position of a feeding pipe. The image processing of the red fire region is extracted. According to the temperature distribution shape of the red fire layer of the cross section of the sintering machine tail, the red fire layer temperature characteristic value is extracted, the lower edge curve function f1 of the red fire layer and the upper edge curve function f2 of the red fire layer are obtained, f2 is a function with the midpoint of the transverse width of the sintering trolley as the origin, the width as the abscissa x, and the 500℃ isotherm of the upper layer of the red fire layer corresponding to the height of the ordinate f2 from the bottom of the trolley; f1 is also a function with the midpoint of the transverse width of the sintering trolley as the origin, the width as the abscissa x, and the 700℃ isotherm of the lower layer of the red fire layer corresponding to the height of the ordinate f1 from the bottom of the trolley; the average thickness of the red fire layer in each region grid at the tail of the sintering trolley is h=f2-f1; the feeding pipe speed is adjusted according to the average thickness h in the region grid; secondary bottoming is carried out on the primary bottoming by the feeding pipe; 3) Laying of sintering mixture: on the basis of secondary bottoming, lay the sintering mixture and level it, and ignite and sinter it; In step 1), the particle size of the finished ore is 10-20 mm, and the thickness of the primary bottoming is 10-30 mm.

2. The method of improving the permeability of a thick sintering layer according to claim 1, wherein, If 3 trolleys or more continuously appear h<50 mm or 3 h<50 mm alternately appear at intervals of 6 trolleys in the i-th region grid on the sintering machine, the corresponding feeding speed φ of each row of the i-th feeding pipe is 0; If 3 trolleys or more continuously appear 50mm≤h≤100mm or 3 50mm≤h≤100mm alternately appear at intervals of 6 trolleys in the i-th region grid on the sintering machine, the corresponding feeding speed φ of each row of the i-th feeding pipe is 30±3 kg / h; If 2 trolleys or more continuously appear h>100mm or 2 h>100mm alternately appear at intervals of 4 trolleys in the i-th region grid on the sintering machine, the corresponding feeding speed φ of each row of the i-th feeding pipe is 50±5 kg / h.

3. The method of improving the permeability of a thick sintering layer according to claim 1, wherein In step 1), the material is laid on the sintering trolley by the bin and the distributor, and the bottoming is leveled by the bottoming leveling plate.

4. The method of improving the permeability of a thick sintering layer according to claim 1, wherein In step 2), 1≤n≤3, 10≤m≤30.

5. The method of improving the permeability of a thick sintering layer according to claim 1, wherein In step 2), the feeding pipe is arranged between the sintering machine bottoming leveling plate and the nine-roll distributor.

6. The method of improving the permeability of a thick sintering layer according to claim 1, wherein In step 3), the ignition sintering conditions are: the ignition temperature range is 950-1050℃, the exhaust negative pressure range is 8000-10500 Pa, and the ignition time range is 1.5-2 min.

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