Device and method for briquetting of blast furnace return fines

Abstract

The application belongs to the technical field of sintering, and is a device for pressing balls of blast furnace return fines, comprising: a stirring device for stirring blast furnace return fines, laterite nickel ore and a binder according to a set mass ratio; a roller pressing device for roller pressing the stirred material transferred from the stirring device by a transfer device to form semi-finished wet material balls; and a drying device for drying the semi-finished wet material balls transferred from the roller pressing device by a transfer device to obtain finished balls. The device for pressing balls of blast furnace return fines avoids excessive blast furnace return fines from being recycled and reburned in a sintering system, releases sintering capacity, reduces energy consumption, and reduces environmental pollution in sintering.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of sintering, and particularly relates to a device and method for pressing sintering balls of blast furnace return fines. BACKGROUND

[0002] In domestic blast furnace production, sintered ore is the main raw material, and iron material accounts for 60-90%. About 30% of the sintered ore in the production process is recycled and resintered, and the sintered ore with a particle size greater than 5 mm under the blast furnace tank can be directly used as a finished product for smelting.

[0003] Blast furnace return fines refer to sintered ore powder with a particle size less than 5 mm screened out from the blast furnace tank. A large proportion of small particle size sintered ore in the blast furnace return fines is sent to the sintering plant, and after mixing and sintering, it is returned to the blast furnace tank. However, the return fines repeatedly go back and forth between the iron mill and the sintering plant, and the repeated sintering process greatly increases the production cost and energy consumption. After the sintered ore is sized, the particle size is greater than 5 mm, but crushing occurs during belt operation and unloading. In order to ensure good permeability in the blast furnace, the sintered ore is screened before entering the blast furnace, and the sintered ore with a particle size less than 5 mm is returned to the sintering process for re-production.

[0004] After the small particle size sintered ore is cold consolidated and formed, it is returned to the blast furnace, realizing resource recycling and utilization, reducing environmental pollution, and reducing energy consumption. The cold consolidation forming process is to add a proper binder to various dust generated in the steel production process, mix uniformly, and under a certain pressure, the mixed material is pressed into a block-shaped material with a certain shape, size, density and strength. After drying or natural solidification, it becomes a briquette with high strength. However, drying increases energy consumption, production cost is high and has certain environmental pollution. The natural drying process has no energy consumption, but the drying speed of the briquette is slow, which leads to poor performance of the binder, slow increase in strength, and low water content of the briquette, greatly reducing the metallurgical effect of the product, and requiring a large natural drying site.

[0005] Taking a certain plant as an example, sintered ore accounts for 90% of the iron-containing furnace charge in blast furnace production, and 35% of the blast furnace return fines in the sintering process are recycled and resintered. The annual blast furnace return fines reach 900,000 tons, and the energy consumption of sintered products per ton of return fines is 50 Kggce / t, and the annual energy consumption of sintered products of return fines is 45,000,000 Kggce / t.

[0006] The existing technology has the following defects and deficiencies: the current return fine method leads to insufficient sintering production capacity, high energy consumption, increased cost, and increased environmental pressure, which does not meet the requirements of the national carbon peak and carbon neutralization policy. SUMMARY

[0007] The application provides a device and method for high furnace return ore ball pressing, and solves the problems of high energy consumption and recycling and reburning of the existing return ore in the sintering system.

[0008] To achieve the above object, the application provides the following technical scheme.

[0009] The device for high furnace return ore ball pressing comprises a stirring device, a roller pressing device and a drying device.

[0010] Further, in the device, the stirring device comprises a mixing bin and a stirring bin.

[0011] Further, in the device, the stirring bin comprises a first double-shaft stirrer stirring bin, a second double-shaft stirrer stirring bin, a first double-shaft stirrer and a second double-shaft stirrer.

[0012] Further, in the device, the feeding device for providing the stirring bin with the binder comprises a third belt scale and a third belt conveyor.

[0013] Further, in the device as described above, further comprising a screening device, the screening device is used to screen the semi-finished wet material balls generated by the roller pressing device, to screen out waste with a size smaller than a set size, and to transport the screened semi-finished wet material balls to the drying device.

[0014] Further, in the device as described above, the drying device comprises a drying chamber, a chain plate machine, and a plug valve arranged in the drying chamber; the plug valve is used to carry the semi-finished wet material balls to be dried screened by the screening device; the drying chamber is used to provide space for drying the semi-finished wet material balls; a chain plate machine is arranged below the plug valve, and the chain plate machine is used to transport the finished balls falling from the plug valve to a finished product warehouse.

[0015] Further, in the device as described above, the transfer device comprises: a first belt scale arranged below the first bin, used to weigh the laterite nickel ore in the first bin and transport the laterite nickel ore to the mixing bin; a second belt scale arranged below the second bin, used to weigh the blast furnace return ore in the second bin and transport the blast furnace return ore to the mixing bin; a first conveyor belt arranged below the mixing bin, used to transport the mixed material from the mixing bin to the first double-shaft mixer stirring bin; a first belt conveyor, used to transport the material output by the stirring device to the roller pressing device; a second conveyor belt arranged below the roller pressing device, used to transport the semi-finished wet material balls from the roller pressing device to the second belt conveyor; a second belt conveyor, used to transport the semi-finished wet material balls from the second conveyor belt to the screening device; and a third conveyor belt arranged below the screening device, used to transport the waste smaller than the set size from the screening device to the first double-shaft mixer stirring bin.

[0016] A method for pressing blast furnace return ore balls, the working steps of the method for pressing blast furnace return ore balls are: first step of mixing and stirring: mixing and stirring the blast furnace return ore, the laterite nickel ore, and the binder according to the set mass ratio; second step of pressing and forming: pressing the stirred material into semi-finished wet material balls; third step of drying: drying the semi-finished wet material balls into finished balls.

[0017] Further, before the first step of mixing and stirring, further comprising: mixing the raw materials of laterite nickel ore and blast furnace return ore according to the set mass ratio to obtain mixed material, and then adding a certain mass ratio of binder for mixing; wherein the mass ratio of laterite nickel ore is 8-15%, the mass ratio of blast furnace return ore is 81-89%, and the mass ratio of binder is 3-5%.

[0018] Further, between the second step of ball pressing forming and the third step of drying, further comprising: screening the semi-finished product wet material ball through a mine screen; screening out the semi-finished product wet material ball greater than or equal to 25mm; and sending the semi-finished product wet material ball less than 25mm back to the first double-shaft mixer stirring bin for stirring.

[0019] Further, the mass ratio of the laterite nickel ore is 15%, the mass ratio of the blast furnace return ore is 81%, and the mass ratio of the binder is 4%.

[0020] The technical scheme of the present application has the following beneficial effects:

[0021] 1. Avoiding the excessive blast furnace return ore from being recycled and reburned in the sintering system, and releasing the sintering production capacity;

[0022] 2. Reducing the energy consumption and reducing the sintering environmental pollution;

[0023] 3. The blast furnace return ore ball (semi-finished product wet material ball) replaces part of the sintered ore, increases the blast furnace clinker ratio, greatly reduces the blast furnace fuel ratio, and increases the stability and continuity of the blast furnace production;

[0024] 4. The blast furnace return ore ball (semi-finished product wet material ball) has uniform particle size, low moisture and less powder, and improves the permeability of the material column. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a ball pressing schematic diagram of the device for pressing the blast furnace return ore ball of the present application;

[0026] Figure 2 It is a mixing schematic diagram of the device for pressing the blast furnace return ore ball of the present application;

[0027] Figure 3 It is a stirring schematic diagram of the device for pressing the blast furnace return ore ball of the present application;

[0028] Figure 4 It is a screening schematic diagram of the device for pressing the blast furnace return ore ball of the present application;

[0029] Figure 5 It is a screen plate schematic diagram of the device for pressing the blast furnace return ore ball of the present application;

[0030] Figure 6 It is a drying schematic diagram of the device for pressing the blast furnace return ore ball of the present application.

[0031] Figure number explanation: first stock bin 1, second stock bin 2, dust removal pipeline 3, first belt scale 4, mixing stock bin 5, first conveyor belt 6, dust removal fume hood 7, second belt scale 8, dust removal ash bin 9, dust remover 10, induced draft fan 11, chimney 12, double-horizontal-shaft mixer feed inlet 13, first double-horizontal-shaft mixer stirring bin 14, observation window 15, binder feeding inlet 16, binder barrel 17, spiral cage 18, binder feeding platform 19, first double-horizontal-shaft mixer stirring bin discharge outlet 20, second double-horizontal-shaft mixer stirring bin 21, second double-horizontal-shaft mixer stirring bin discharge outlet 22, first belt conveyor 23, high-pressure ball press machine feed inlet 24, spiral conveyor 25, compression roller 26, second conveyor belt 27, second belt conveyor 28, mine screen 29, material blocking screen 30, third conveyor belt 31, screen plate 32, coal gas pipeline 33, air blower 34, combustion chamber 35, air extractor 36, hot air pipeline 37, hot air furnace feed inlet 38, drying chamber 39, plug valve 40, chain plate machine 41. DETAILED DESCRIPTION

[0032] In order to make the objects, technical solutions and advantages of the present application clearer, the following will further describe the embodiments of the present application with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0033] In the description of the present application, it should be noted that the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "two ends", "one end", "the other end" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0034] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "provided with", "connection" and the like should be understood broadly, for example, "connection" can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0035] Referring to the drawings Figures 1-6The device for pressing the blast furnace return fines balls is introduced in detail, wherein, Figure 1 The device for pressing the blast furnace return fines balls is introduced in detail, wherein, Figure 2 The device for pressing the blast furnace return fines balls is introduced in detail, wherein, Figure 3 The device for pressing the blast furnace return fines balls is introduced in detail, wherein, Figure 4 The device for pressing the blast furnace return fines balls is introduced in detail, wherein, Figure 5 The device for pressing the blast furnace return fines balls is introduced in detail, wherein, Figure 6 The device for pressing the blast furnace return fines balls is introduced in detail, wherein,

[0036] Briefly, the device for pressing the blast furnace return fines balls is described as follows:

[0037] The device for pressing the blast furnace return fines balls comprises a rolling device, a drying device, a stirring device, a dust removal device, a screening device and a transfer device.

[0038] The stirring device is used for stirring the blast furnace return fines, the laterite nickel ore and the binder according to the set mass ratio.

[0039] The rolling device is used for rolling the stirred material transferred from the stirring device by the transfer device to form semi-finished wet material balls.

[0040] The drying device is used for drying the semi-finished wet material balls transferred from the rolling device by the transfer device to obtain finished balls.

[0041] The transfer device is used for transferring the material between the stirring device, the rolling device and the drying device.

[0042] The stirring device comprises a mixing bin and a stirring bin, wherein:

[0043] The mixing bin comprises a first bin 1, a second bin 2 and a mixing bin 5, the first bin 1 is used for loading the laterite nickel ore, the second bin 2 is used for loading the blast furnace return fines, and the mixing bin 5 is used for mixing the laterite nickel ore and the blast furnace return fines according to the set mass ratio to obtain the mixed material.

[0044] The stirring bin comprises a binder supply device and a stirring bin, the binder supply device comprises a binder bin 17 and a supply device for supplying the binder to the stirring bin, and the binder bin 17 is used for loading the binder.

[0045] The stirring bin is used for providing a place for stirring the laterite nickel ore, the blast furnace return fines and the binder according to the set mass ratio.

[0046] The stirring bin comprises a first double-shaft stirring bin 14 and a second double-shaft stirring bin 21.

[0047] The stirring device comprises a first double-shaft stirrer and a second double-shaft stirrer.

[0048] The first double-shaft stirrer is installed in the first double-shaft stirrer stirring bin 14 and is used for stirring the mixed material and the binder with a set mass ratio for the first time to obtain first stirred material; the second double-shaft stirrer is installed in the second double-shaft stirrer stirring bin 21 and is used for stirring the first stirred material for the second time to obtain second stirred material as the above-mentioned material (i.e. the material after stirring is completed).

[0049] The feeding device for providing the binder to the stirring bin comprises a third belt scale and a third belt conveyor,

[0050] The third belt scale is arranged below the binder bin 17 and is used for weighing the binder in the binder bin 17 and conveying the binder to the third belt conveyor;

[0051] The third belt conveyor is arranged below the third belt scale and is used for conveying the binder weighed by the third belt scale according to the set mass ratio to the first double-shaft stirrer stirring bin 14;

[0052] Before drying, the device for pressing the blast furnace return fines into balls further comprises a screening device for screening the semi-finished wet material balls generated by the rolling device to remove waste with a size less than a set size, and conveying the screened semi-finished wet material balls to the drying device. The screening device comprises a mineral screen 29 for screening out semi-finished wet material balls with a size greater than or equal to a certain size; semi-finished wet material balls with a size greater than or equal to 25 mm are screened out through the mineral screen 29.

[0053] The transfer device comprises a first belt scale 4, a second belt scale 8, a first conveyor belt 6, a second conveyor belt 27, a third conveyor belt 31, a first belt conveyor 23 and a second belt conveyor 28.

[0054] The first belt scale 4 is arranged below the first bin 1 and is used for weighing the laterite nickel ore in the first bin 1 and conveying the laterite nickel ore to the mixed material bin 5;

[0055] The second belt scale 8 is arranged below the second bin 2 and is used for weighing the blast furnace return fines in the second bin 2 and conveying the blast furnace return fines to the mixed material bin 5;

[0056] The first conveyor belt 6 is arranged below the mixed material bin 5 and is used for conveying the mixed material from the mixed material bin 5 to the first double-shaft stirrer stirring bin 14;

[0057] The first belt conveyor 23 is used for conveying the material output by the stirring device to the rolling device;

[0058] A second conveyor belt 27 is arranged below the roller pressing device, and is used to transport the semi-finished wet material balls from the roller pressing device to a second belt conveyor 28;

[0059] The second belt conveyor 28 is used to transport the semi-finished wet material balls from the second conveyor belt 27 to the screening device;

[0060] A third conveyor belt 31 is arranged below the screening device, and is used to transport the waste material smaller than the set size from the screening device to the first double-horizontal-shaft mixer mixing bin 14.

[0061] The roller pressing device is a high-pressure ball press, which comprises a pressing roller 26 arranged at the lower part of the high-pressure ball press, and is used to press the second mixed material into semi-finished wet material balls of a certain size.

[0062] The drying device comprises a drying chamber 39, a chain plate machine 41, and a plug valve 40 arranged in the drying chamber 39; the plug valve 40 is used to carry the semi-finished wet material balls to be dried, that is, the plug valve 40 is used to carry the semi-finished wet material balls to be dried screened from the screening device; the drying chamber 39 is used to provide space for drying the semi-finished wet material balls; the chain plate machine 41 is arranged below the plug valve 40, and is used to transport the finished balls falling from the plug valve 40 to a finished product warehouse.

[0063] The blast furnace return fines ball pressing device further comprises a dust removal device, which comprises a dust remover 10 used to remove the dust generated during the transportation of the laterite nickel ore and the blast furnace return fines to the mixing bin 5; a dust removal ash bin 9 is arranged below the dust remover 10, and is used to store the dust precipitated after dust removal; the dust removal device further comprises an induced draft fan 11 used to guide the flue gas generated during dust removal to be discharged through a chimney 12.

[0064] Preferably, the dust remover 10 is a bag-type dust remover.

[0065] The method for pressing balls of blast furnace return fines comprises the following steps:

[0066] The first step is mixing and stirring: the blast furnace return fines, the laterite nickel ore, and the binder mixed according to the set mass ratio are mixed and stirred;

[0067] The second step is ball pressing and forming: the mixed and stirred material is pressed into semi-finished wet material balls;

[0068] The third step is drying: the semi-finished wet material balls are dried into finished balls.

[0069] Before the first step of mixing and stirring, the raw materials of laterite nickel ore and blast furnace return ore are mixed according to the set mass ratio to obtain a mixture, and then a certain mass ratio of binder is added for mixing; wherein the mass ratio of laterite nickel ore is 8-15%, the mass ratio of blast furnace return ore is 81-89%, and the mass ratio of binder is 3-5%; preferably, the mass ratio of laterite nickel ore is 15%, the mass ratio of blast furnace return ore is 81%, and the mass ratio of binder is 4%.

[0070] Before the third step of drying, the semi-finished product wet material ball needs to be screened through the ore screen 29; the semi-finished product wet material ball greater than or equal to 25mm is screened out; the semi-finished product wet material ball less than 25mm is sent back to the first double-shaft stirrer stirring bin 14 for stirring.

[0071] In addition, in the first step, the above mixture and the above binder are first stirred in the first double-shaft stirrer stirring bin 14, the first double-shaft stirrer is set to rotate at 60r / min, and the stirring time is 3min to obtain the first stirred material; the first stirred material is second stirred in the second double-shaft stirrer stirring bin 21, the second double-shaft stirrer is set to rotate at 80r / min, and the stirring time is 3min to obtain the second stirred material.

[0072] The device and method for pressing blast furnace return ore balls provided by the application will be discussed in detail below.

[0073] The device for pressing blast furnace return ore balls includes the roller pressing device, the drying device, the stirring device, the dust removal device, the screening device and the transfer device mentioned in the above embodiments;

[0074] The mixing bin includes a first material bin 1, a second material bin 2 and a mixture bin 5, the first material bin 1 is used for containing laterite nickel ore, the second material bin 2 is used for containing blast furnace return ore, and the mixture bin 5 is used for mixing laterite nickel ore and blast furnace return ore according to the set mass ratio to obtain a mixture;

[0075] The stirring bin includes a binder supply device and a stirred material bin, the binder supply device includes a binder bin 17 and a supply device for providing binder to the stirred material bin, and the binder bin 17 is used for containing binder. According to the mass ratio of laterite nickel ore to blast furnace return ore, the amount of binder is adjusted to ensure uniform distribution of the binder and improve the use efficiency. The binder can be a liquid binder or a solid binder. The solid binder needs to be mixed with a certain amount of water, for example, a certain brand of powder solid binder is mixed with water to obtain a liquid binder, and the mass ratio of water to solid binder is 2:1.

[0076] The stirred material bin is used for providing a place for stirring laterite nickel ore, blast furnace return ore and binder according to the set mass ratio.

[0077] The mixing bins include a first twin-shaft mixer mixing bin 14 and a second twin-shaft mixer mixing bin 21; the first twin-shaft mixer mixing bin 14 provides a mixing space for the first mixing; the second twin-shaft mixer mixing bin 21 provides a mixing space for the second mixing.

[0078] In one specific embodiment, the supply device for providing binder to the mixing silo is a screw conveyor 18, which conveys the binder to the mixing chamber 14 of the first twin-shaft mixer.

[0079] In another specific embodiment, the supply device for providing binder to the mixing silo is a third belt conveyor, which transports the binder to the mixing silo 14 of the first twin-shaft mixer.

[0080] like Figure 1 As shown, the first silo 1 has a discharge port at its lower part, and a first belt scale 4 is located below it. 15% of the dried laterite nickel ore is weighed by the first belt scale 4 and sent to the mixing silo 5. The laterite nickel ore is dried to a moisture content of less than or equal to 16% by a rotary kiln (furnace outlet temperature 1050℃, rotation speed 600r / min). The second silo 2 has the same structure as the first silo 1, with a discharge port at its lower part. A second belt scale 8 is located below it, and 81% of the blast furnace return ore is weighed by the second belt scale 8 and sent to the mixing silo 5 to be mixed with the 15% dried laterite nickel ore to obtain a mixture. The mixing silo 5 is located below the first belt scale 4 and also below the second belt scale 8.

[0081] Dust is generated during the process of transporting laterite nickel ore and blast furnace return ore to the mixing silo 5. The dust is removed by a dust removal device (i.e., dust collector 10). The dust removal device includes: dust collection silo 9, dust collector 10, induced draft fan 11, and chimney 12.

[0082] Dust collection duct 3 is located above the first silo 1 and the second silo 2. The dust enters the dust collector 10 through the dust collection duct 3 for dust collection. Preferably, the dust collector 10 is a bag filter. Dust collection hopper 9 is located below the dust collector 10. After dust collection, the dust settles into the dust collection hopper 9. Multiple dust collection hoppers 9 can be provided, preferably two. A dust discharge outlet is provided at the bottom of the dust collection hopper 9. A trolley can be provided below the dust discharge outlet to transport the dust out of the dust collection hopper 9. In one specific embodiment, the dust is transported to a dust storage silo. The flue gas generated by dust collection is discharged through the chimney 12 under the action of the induced draft fan 11.

[0083] In one specific embodiment, a dust removal hood 7 is provided above the mixing silo 5 for dust removal. The dust removal hood 7 is connected to the dust removal pipe 3, so that dust can enter the dust collector 10 through the dust removal pipe 3.

[0084] The first conveyor belt 6 is located below the mixing silo 5. The mixing silo 5 has a mixing silo outlet at its lower part. The mixing material is transported to the twin-shaft mixer inlet 13 by the first conveyor belt 6. The twin-shaft mixer inlet 13 is located at the upper part of the twin-shaft mixer. The mixing material is transported into the first twin-shaft mixer mixing chamber 14 through the twin-shaft mixer inlet 13.

[0085] In one specific implementation, such as Figure 2 As shown, the rotation speed of the screw conveyor 18 is set to 50 r / min, and the binder is conveyed through the screw conveyor 18 to the mixing chamber 14 of the first twin-shaft mixer at a ratio of 4% for mixing.

[0086] In another specific embodiment, a third belt scale (not shown) is provided below the adhesive hopper 17, and a third belt conveyor is provided below the third belt scale; 4% of the adhesive is weighed by the third belt scale and the weighed adhesive is transported to the third belt conveyor, and then the third belt conveyor transports the adhesive to the mixing chamber 14 of the first twin-shaft mixer.

[0087] The mixing device includes: a first twin-shaft mixer and a second twin-shaft mixer; the two mixing processes are to make the materials more evenly mixed. The rotation speed settings of the two mixing processes are different, with the second mixing process having a higher rotation speed and stronger intensity than the first mixing process.

[0088] The first twin-shaft mixer includes a twin-shaft mixer inlet 13 and a first twin-shaft mixer mixing chamber outlet 20;

[0089] The second twin-shaft mixer includes: the discharge port 22 of the mixing chamber of the second twin-shaft mixer.

[0090] like Figure 2 As shown, the speed of the first twin-shaft mixer is set to 60 r / min. The binder and the mixture are first mixed in the mixing chamber 14 of the first twin-shaft mixer for 3 minutes to obtain the first mixed material. The discharge port 20 of the first twin-shaft mixer is located at the lower part of the mixing chamber 14. The first mixed material is fed into the mixing chamber 21 of the second twin-shaft mixer through the discharge port 20 for a second mixing. The mixing chamber 21 of the second twin-shaft mixer is located below the mixing chamber 14. The speed of the second twin-shaft mixer is set to 80 r / min and mixed for 3 minutes to obtain the second mixed material.

[0091] In an embodiment, the first double-shaft mixer is provided with an observation window 15 on the stirring bin 14, which is made of transparent material, such as glass, resin, etc., through which the stirring condition in the first double-shaft mixer stirring bin 14 can be observed.

[0092] In an embodiment, the first double-shaft mixer stirring bin 14 is provided with an adhesive feeding platform 19 on the outside, the bottom of which is higher than the discharge port 20 of the first double-shaft mixer stirring bin, and the adhesive feeding platform 19 provides support for the adhesive tank 17, that is, the adhesive tank 17 can be arranged on the adhesive feeding platform 19.

[0093] The second double-shaft mixer stirring bin discharge port 22 is arranged at the lower part of the second double-shaft mixer stirring bin 21, and the second stirring material is transported to the first belt conveyor 23 through the second double-shaft mixer stirring bin discharge port 22, and the first belt conveyor 23 is arranged below the second double-shaft mixer stirring bin 21.

[0094] The roller pressing device is a ball press, preferably a high-pressure ball press; the specification of the high-pressure ball press is required to be greater than or equal to 200 KN / CM; the high-pressure ball press is taken as an example for specific introduction, which includes a pressing roller 26, that is, the stirring material is pressed into semi-finished wet material balls by the pressing roller 26.

[0095] Specifically, the second stirring material is transported to the high-pressure ball press feeding port 24 by the first belt conveyor 23, and the high-pressure ball press feeding port 24 is arranged at the upper part of the high-pressure ball press, and then the second stirring material is transported to the pressing roller 26 by the screw conveyor 25; the pressing roller 26 is arranged at the lower part of the high-pressure ball press.

[0096] The diameter of the pressing roller 26 of the high-pressure ball press is set to 800 mm, the roller width is set to 500 mm, the maximum pressure between the rollers is set to 380 t, and the linear specific pressure is set to 8 t / cm, and the pressing roller 26 presses the second stirring material into semi-finished wet material balls with a specification of 50*40*25 mm.

[0097] The second conveying belt 27 is arranged below the pressing roller 26, and the above-mentioned semi-finished wet material balls are naturally transported onto the second conveying belt 27 by their own gravity.

[0098] Between the roller pressing device and the drying device, a screening device is further included;

[0099] The screening device includes a mineral screen 29 and a material blocking screen 30.

[0100] As Figure 4 , Figure 5As shown, the semi-finished wet material balls are transported to the ore screen 29 through the second conveying belt 27 and the second belt conveyor 28; the inclination angle of the second belt conveyor 28 is controlled to be below 35°, so as to ensure that the semi-finished wet material balls will not roll out of the second belt conveyor 28 during the transportation.

[0101] The ore screen 29 is used for screening the semi-finished wet material balls generated by the rolling device, and the waste with a size smaller than a set size is screened out, and the screened semi-finished wet material balls are transported to the drying device. Preferably, the set screening size is 25 mm, the third conveying belt 31 is arranged below the ore screen 29, the ore screen 29 is provided with a screen plate 32, and the semi-finished wet material balls are screened through the screen plate 32 with a pore size of 25 mm, wherein the semi-finished wet material balls smaller than 25 mm will fall onto the third conveying belt 31 and be re-fed into the first double-shaft mixer mixing bin 14 for mixing, and the semi-finished wet material balls larger than 25 mm will directly fall to the ground and be collected and transported to the drying chamber 39 for drying.

[0102] In a specific embodiment, a material blocking screen 30 is arranged between the second belt conveyor 28 and the ore screen 29, the material blocking screen 30 is in a vertical state and located above the third conveying belt 31, and is used for blocking the semi-finished wet material balls smaller than 25 mm to prevent them from splashing.

[0103] The transfer device is used for transferring the material between the mixing device, the rolling device and the drying device.

[0104] The transfer device includes the first belt scale 4, the second belt scale 8, the first conveying belt 6, the first belt conveyor 23, the second conveying belt 27, the second belt conveyor 28 and the third conveying belt 31.

[0105] The first belt scale 4 is arranged below the first material bin 1, and is used for weighing the laterite nickel ore in the first material bin 1 and transporting the laterite nickel ore to the mixed material bin 5.

[0106] The second belt scale 8 is arranged below the second material bin 2, and is used for weighing the blast furnace return ore in the second material bin 2 and transporting the blast furnace return ore to the mixed material bin 5.

[0107] The first conveying belt 6 is arranged below the mixed material bin 5, and is used for transporting the mixed material from the mixed material bin 5 to the first double-shaft mixer mixing bin 14.

[0108] The first belt conveyor 23 is used for transporting the second mixed material output by the mixing device to the high-pressure ball press.

[0109] The second conveying belt 27 is arranged below the rolling roller 26, and is used for transporting the semi-finished wet material balls from the rolling roller 26 to the second belt conveyor 28.

[0110] The second belt conveyor 28 is used to transport the semi-finished wet pellets from the second conveyor belt 27 to the mining screen 29;

[0111] The third conveyor belt 31 is located below the mineral screen 29 and is used to transport semi-finished wet material balls smaller than 25mm from the mineral screen 29 to the mixing chamber 14 of the first twin-shaft mixer.

[0112] The drying device includes: a gas pipeline 33, a blower 34, a combustion chamber 35, an exhaust fan 36, a hot air pipeline 37, a hot air furnace inlet 38, a drying chamber 39, and a chain conveyor 41;

[0113] like Figure 6 As shown, in one specific embodiment, a forklift is used to collect the semi-finished wet material balls larger than 25mm that have fallen to the ground; a slide gate valve 40 is provided in the drying chamber 39 to carry the aforementioned semi-finished wet material balls. The semi-finished wet material balls larger than 25mm that have fallen to the ground are collected and transported to the slide gate valve 40 of the drying chamber 39 (also called "vertical kiln") through the hot air furnace inlet 38; that is, the slide gate valve 40 carries the semi-finished wet material balls to be dried collected after being screened in the screening device.

[0114] In use, the gas valve is opened, and the blower 34 drives the gas through the gas pipe 33 into the combustion chamber 35 for combustion. The generated hot air, under the action of the exhaust fan 36, is blown into the drying chamber 39 through the hot air pipe 37. The temperature of the hot air entering the drying chamber 39 is controlled at 260-300℃. The above-mentioned semi-finished wet material blocks are dried in the drying chamber 39 for 120-150 minutes until the moisture content of the semi-finished wet material balls drops to below 2% (to ensure the strength of the finished balls). A chain conveyor 41 is installed below the slide valve 40. When one end of the slide valve 40 is opened, the finished balls fall onto the chain conveyor 41 and are transported to the finished product warehouse via the chain conveyor 41. In other words, the chain conveyor 41 is used to transport the finished balls falling from the slide valve 40 to the finished product warehouse. The temperature of the finished balls exiting the drying chamber 39 exceeds 100℃. The finished balls have uniform particle size, low moisture content, little powder, and high air permeability.

[0115] Take an appropriate amount of finished balls according to the actual production needs of the blast furnace and transport them to the blast furnace for direct use.

[0116] The method for briquetting blast furnace return ore includes the steps mentioned above: first, mixing and stirring; second, briquetting and forming; and third, drying. The specific steps are described in detail below.

[0117] Step 1: Mixing and Stirring: Before mixing and stirring, the raw materials in this embodiment include laterite nickel ore, blast furnace return ore, and binder; the three raw materials are stored in the first silo 1, the second silo 2, and the binder hopper 17, respectively; the raw materials are proportioned according to a certain mass ratio, specifically as shown below:

[0118] The recommended proportions are: laterite nickel ore content 15%, blast furnace return ore content 81%, and binder content 4%. The final proportions can be adjusted according to requirements. Specifically, the laterite nickel ore content ranges from 8-15%, the blast furnace return ore content ranges from 81-89%, and the binder content ranges from 3-5%.

[0119] The laterite nickel ore is dried before mixing to a moisture content of less than or equal to 16%. Specifically, the laterite nickel ore is dried in a rotary kiln (furnace outlet temperature 1050℃, rotation speed 600r / min) to a moisture content of less than or equal to 16%, and then placed in warehouse A. Blast furnace return ore is placed in warehouse B. An appropriate amount of dried laterite nickel ore is placed in the first silo 1, and an appropriate amount of blast furnace return ore is placed in the second silo 2 for later use. A binder hopper 17 is set above the left side of the twin-shaft mixer. The binder is fed into the binder hopper 17 through the binder feeding port 16 for later use.

[0120] Mixing and stirring: such as Figure 1 As shown, the first silo 1 has a discharge port at its lower part, and a first belt scale 4 is located below it. 15% of the dried laterite nickel ore is weighed out by the first belt scale 4. The second silo 2 has the same structure as the first silo 1, with a discharge port at its lower part and a second belt scale 8 located below it. 81% of the blast furnace return ore is weighed out by the second belt scale 8. Both are then sent to a mixing silo 5 for mixing to obtain a mixture. The mixing silo 5 is located below the first belt scale 4 and also below the second belt scale 8.

[0121] Dust is generated during the process of transporting laterite nickel ore and blast furnace return ore to the mixing silo 5, requiring a dust removal device. The dust removal device includes: a dust collection silo 9, a dust collector 10, an induced draft fan 11, and a chimney 12.

[0122] Dust collection duct 3 is located above the first silo 1 and the second silo 2. The dust enters the dust collector 10 through the dust collection duct 3 for dust removal. Preferably, the dust collector 10 is a bag filter. Dust collection hopper 9 is located below the dust collector 10. After dust removal, the dust settles into the dust collection hopper 9. The lower part of the dust collection hopper 9 is provided with a dust discharge outlet. A trolley can be installed below the dust discharge outlet to transport the dust out of the dust collection hopper 9. In one specific embodiment, the dust is transported to a dust storage silo. The flue gas generated by dust removal is discharged from the chimney 12 through the induced draft fan 11.

[0123] In one specific embodiment, a dust removal hood 7 is provided above the mixing silo 5 for dust removal. The dust removal hood 7 is connected to the dust removal pipe 3, so that dust can enter the dust collector 10 through the dust removal pipe 3.

[0124] The first conveyor belt 6 is arranged below the mixing bin 5, and the lower part of the mixing bin 5 is provided with a mixing bin discharge port. The mixed material from the mixing bin 5 is transported to the double-shaft mixer feed port 13 through the first conveyor belt 6. The double-shaft mixer feed port 13 is arranged at the upper part of the double-shaft mixer. The mixed material is transported into the first double-shaft mixer stirring bin 14 through the double-shaft mixer feed port 13.

[0125] In a specific embodiment, as shown in the figure, the rotating speed of the spiral cage 18 is set to 50 r / min. The binder from the binder cartridge is transported into the first double-shaft mixer stirring bin 14 through the spiral cage 18 at a ratio of 4%. The mixed material is mixed. Figure 2

[0126] In another specific embodiment, a third belt scale is arranged below the binder cartridge 17, and a third belt conveyor is arranged below the third belt scale. The binder is weighed by the third belt scale at a ratio of 4%, and the weighed binder is transported to the third belt conveyor. The third belt conveyor transports the binder to the first double-shaft mixer stirring bin 14.

[0127] The stirring device comprises a first double-shaft mixer and a second double-shaft mixer.

[0128] The first double-shaft mixer comprises a double-shaft mixer feed port 13 and a first double-shaft mixer stirring bin discharge port 20.

[0129] The second double-shaft mixer comprises a second double-shaft mixer stirring bin discharge port 22.

[0130] As shown in the figure, the rotating speed of the first double-shaft mixer is set to 60 r / min. The binder and the mixed material are first stirred in the first double-shaft mixer stirring bin 14. After stirring for 3 min, the first stirred material is obtained. The first double-shaft mixer stirring bin discharge port 20 is arranged at the lower part of the first double-shaft mixer stirring bin 14. The first stirred material is input into the second double-shaft mixer stirring bin 21 through the first double-shaft mixer stirring bin discharge port 20 for second stirring. The second double-shaft mixer stirring bin 21 is arranged below the first double-shaft mixer stirring bin 14. The rotating speed of the second double-shaft mixer is set to 80 r / min. After stirring for 3 min, the second stirred material is obtained. Figure 2 In a specific embodiment, an observation window 15 is arranged on the first double-shaft mixer stirring bin 14. The observation window 15 is made of transparent material, such as glass, resin, etc. The stirring condition in the first double-shaft mixer stirring bin 14 can be observed through the observation window 15.

[0131]

[0132] ​​In one specific embodiment, an adhesive feeding platform 19 is provided on the outside of the mixing chamber 14 of the first twin-shaft mixer. The bottom of the adhesive feeding platform 19 is higher than the discharge port 20 of the mixing chamber of the first twin-shaft mixer. The adhesive feeding platform 19 provides support for the adhesive barrel 17. In other words, the adhesive barrel 17 can be set on the adhesive feeding platform 19.

[0133] The discharge port 22 of the mixing chamber of the second twin-shaft mixer is located at the lower part of the mixing chamber 21 of the second twin-shaft mixer. The second mixing material is conveyed to the first belt conveyor 23 through the discharge port 22 of the mixing chamber of the second twin-shaft mixer. The first belt conveyor 23 is located below the mixing chamber 21 of the second twin-shaft mixer.

[0134] The second step is ball pressing and shaping: (as shown in the image) Figure 3 As shown, the first belt conveyor 23 transports the second mixed material to the feed inlet 24 of the high-pressure briquetting machine. The feed inlet 24 of the high-pressure briquetting machine is located at the upper part of the high-pressure briquetting machine. The second mixed material is then transported to the pressure roller 26 by the screw conveyor 25. The pressure roller 26 is located at the lower part of the high-pressure briquetting machine.

[0135] The high-pressure briquetting machine has a roller 26 with a diameter of 800mm, a roller width of 500mm, a maximum pressure between rollers of 380t, and a linear pressure of 8t / cm. The roller 26 presses the second mixed material into semi-finished wet material balls with a specification of 50*40*25mm.

[0136] The second conveyor belt 27 is located below the pressure roller 26, and the aforementioned semi-finished wet material balls are naturally transported onto the second conveyor belt 27 by their own gravity.

[0137] Filtering: such as Figure 4 , Figure 5 As shown, the semi-finished wet material ball is transported to the mining screen 29 via the second conveyor belt 27 and the second belt conveyor 28; wherein, the inclination angle of the second belt conveyor 28 is controlled below 35° to ensure that the semi-finished wet material ball does not roll out of the second belt conveyor 28 during transportation.

[0138] The sieve 29 is used to screen the semi-finished wet pellets generated by the roller pressing device, removing waste materials smaller than a set size, and then conveying the screened semi-finished wet pellets to the drying device. Preferably, the set screening size is 25mm. The third conveyor belt 31 is located below the sieve 29, and the sieve 29 is equipped with a screen plate 32. The semi-finished wet pellets are screened through the screen plate 32 with a 25mm aperture. Semi-finished wet pellets smaller than 25mm will fall onto the third conveyor belt 31 and be sent back to the mixing chamber 14 of the first twin-shaft mixer for mixing. Semi-finished wet pellets larger than 25mm will fall directly to the ground, be collected, and conveyed to the drying chamber 39 for drying.

[0139] In a specific embodiment, a material blocking screen 30 is arranged between the second belt conveyor 28 and the ore screen 29, the material blocking screen 30 is in a vertical state and is located above the third conveyor belt 31, and is used to block the semi-finished wet material balls less than 25 mm to prevent them from splashing.

[0140] The third step of drying: as shown in the figure, the forklift is used to collect the semi-finished wet material balls greater than 25 mm falling to the ground; the plug valve 40 is arranged in the drying chamber 39, and is used to carry the semi-finished wet material balls to collect the semi-finished wet material balls greater than 25 mm falling to the ground through the hot blast furnace feeding port 38 to the plug valve 40 of the drying chamber 39 (also referred to as a shaft kiln); that is, the plug valve 40 carries the semi-finished wet material balls collected after screening by the screening device to be dried. Figure 6

[0141] In use, the gas valve is opened, the gas is pushed by the air blower 34, enters the combustion chamber 35 through the gas pipeline 33 to burn, and the hot air generated under the action of the air blower 36 is blown into the drying chamber 39 through the hot air pipeline 37; the temperature of the hot air entering the drying chamber 39 is controlled at 260-300℃, and the above-mentioned semi-finished wet material blocks are dried in the drying chamber 39 for 120-150 minutes until the moisture of the semi-finished wet material balls is reduced to within 2% (to ensure the strength of the finished balls) to obtain the finished balls; the plug valve 40 is provided below the chain plate machine 41, one end of the plug valve 40 is opened, and the finished balls fall onto the chain plate machine 41; the finished balls are transported to the finished ball warehouse through the chain plate machine 41; that is, the chain plate machine 41 is used to transport the finished balls falling from the plug valve 40 to the finished ball warehouse; the temperature of the finished balls out of the drying chamber 39 exceeds 100℃. The finished balls have uniform particle size, low moisture, less powder and high air permeability.

[0142] According to the actual production needs of the blast furnace, an appropriate amount of finished balls is transported to the blast furnace for direct use.

[0143] In order to realize that the return ore balling performance of the blast furnace meets the use requirements of the blast furnace smelting, the raw material formula and method suitable for the process are developed; the laterite nickel ore is added as a binding medium; the binder is added to improve the binding capacity of the laterite nickel ore and the balling rate of the blast furnace return ore.

[0144] The above-mentioned method of the blast furnace return ore balling of the present application has no high-temperature treatment, mainly the return ore with a particle size less than 5 mm screened from the blast furnace is directly balling and put into the blast furnace for use. According to the same calculation method, the energy consumption of ton return ore balling product is 10Kggce / t, compared with the energy consumption of the return ore sintering product, the energy consumption of the return ore balling product is reduced by 80% per year, which significantly reduces the sintering energy consumption, reduces environmental pollution, avoids excessive return ore of the blast furnace from being recycled and reburned in the sintering system, and at the same time, the return ore balling of the blast furnace can also replace part of the sintering ore, thereby improving the clinker ratio and being beneficial to the stable production of the blast furnace. ​

[0145] It will be apparent to those skilled in the art that the application can be practiced by other than the described embodiments, which are presented for purposes of illustration and not limitation, and which are not exhaustive. It is contemplated that the application can be practiced in other specific forms without departing from the spirit or essential characteristics thereof. It is also contemplated that the application can be practiced with other than the particular embodiments described, which are presented for purposes of illustration and not limitation. Thus, the scope of the application should be determined not with reference to the above description, but should be given with reference to the appended claims, along with their full scope of equivalents. It is therefore desired that what is claimed be protected as usefully as possible. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus although specific claims can be formulated as means-plus-function claims, it is intended that these claims be interpreted to cover the structures described herein as performing the recited function, and not only structural equivalents, but also equivalent structures. In interpreting the appended claims, all terms should be interpreted in the broadest possible way consistent with the context. In the claims, any means-plus-function claim follows the corresponding functionally-claimed statements. Accordingly, the claims are not limited to the embodiments and illustrations described herein.

Claims

1. A method for briquetting blast furnace return ore, characterized in that... ， A device for briquetting blast furnace return ore, comprising: A mixing device is used to mix blast furnace return ore, laterite nickel ore, and binder according to a set mass ratio; the mixing device includes a mixing chamber and a stirring chamber, wherein: The mixing silo includes a first silo, a second silo, and a mixing silo. The first silo is used to hold laterite nickel ore, the second silo is used to hold blast furnace return ore, and the mixing silo is used to mix the laterite nickel ore and blast furnace return ore fed in according to a set mass ratio to obtain a mixed material. The mixing chamber includes a binder feeding device and a mixing silo. The binder feeding device includes a binder hopper and a supply device for supplying binder to the mixing silo. The binder hopper is used to hold the binder. The mixing silo is used to provide a place for mixing laterite nickel ore, blast furnace return ore, and binder according to a set mass ratio; The mixing device includes a first twin-shaft mixer and a second twin-shaft mixer, and the mixing hopper includes a mixing hopper for the first twin-shaft mixer and a mixing hopper for the second twin-shaft mixer. A roller pressing device is used to press the mixed material transferred from the mixing device by the transfer device to form semi-finished wet material balls. A drying device is used to dry the semi-finished wet material balls transferred from the roller pressing device by the transfer device to obtain finished balls; According to the aforementioned apparatus, the working steps of the blast furnace return ore briquetting method are as follows: Step 1: Mixing and stirring: Mix the blast furnace return ore, laterite nickel ore and binder according to the set mass ratio and then stir. The second step is pelletizing: the mixed materials are pressed into semi-finished wet pellets; The third step is drying: drying the semi-finished wet material balls into finished balls; Before the first step of mixing, the process also includes: mixing the raw materials laterite nickel ore and blast furnace return ore according to a set mass ratio to obtain a mixture, and then adding a certain mass ratio of binder to mix. The mass ratio of laterite nickel ore is 8-15%, the mass ratio of blast furnace return ore is 81-89%, and the mass ratio of binder is 3-5%; the laterite nickel ore is laterite nickel ore that has been dried to a moisture content of less than or equal to 16%. Between the second step of ball forming and the third step of drying, the process also includes: The semi-finished wet pellets are screened through a mineral screen; semi-finished wet pellets with a diameter of 25 mm or larger are screened out. The semi-finished wet pellets smaller than 25mm are fed back into the mixing chamber of the first twin-shaft mixer for mixing.

2. The method according to claim 1, characterized in that, The mass ratio of laterite nickel ore is 15%, the mass ratio of blast furnace return ore is 81%, and the mass ratio of binder is 4%.

3. The method according to claim 1, characterized in that, The first twin-shaft mixer is installed in the mixing chamber of the first twin-shaft mixer and is used to mix the mixture and the binder added according to the set mass ratio for the first time to obtain the first mixed material; The second twin-shaft mixer is installed in the mixing chamber of the second twin-shaft mixer and is used to mix the first mixing material a second time to obtain the second mixing material as the material.

4. The method according to claim 3, characterized in that, The supply device for providing binder to the mixing silo includes: a third belt scale and a third belt conveyor. The third belt scale is located below the adhesive hopper and is used to weigh the adhesive in the adhesive hopper and transport the adhesive to the third belt conveyor. The third belt conveyor is located below the third belt scale and is used to transport the binder weighed by the third belt scale according to a set mass ratio to the mixing chamber of the first twin-shaft mixer.

5. The method according to claim 3, characterized in that, It also includes a screening device, which is used to screen the semi-finished wet material balls generated by the roller pressing device to remove waste materials smaller than a set size, and then convey the screened semi-finished wet material balls to the drying device.

6. The method according to claim 5, characterized in that, The drying device includes a drying chamber, a chain conveyor, and a slide valve installed inside the drying chamber; The slide valve is used to carry the semi-finished wet pellets to be dried after being screened by the screening device; The drying chamber is used to provide space for drying semi-finished wet pellets; A chain conveyor is installed below the slide gate valve, which is used to transport the finished balls that fall from the slide gate valve to the finished product warehouse.

7. The method according to claim 5, characterized in that, The transfer device includes: A first belt scale is installed below the first silo to weigh the laterite nickel ore in the first silo and transport the laterite nickel ore to the mixing silo. The second belt scale is located below the second silo and is used to weigh the blast furnace return ore in the second silo and transport the blast furnace return ore to the mixing silo. A first conveyor belt is disposed below the mixing silo for conveying the mixture from the mixing silo to the mixing chamber of the first twin-shaft mixer; The first belt conveyor is used to transport the material output from the mixing device to the roller pressing device; The second conveyor belt is located below the roller pressing device and is used to transport the semi-finished wet material balls from the roller pressing device to the second belt conveyor. The second belt conveyor is used to transport the semi-finished wet pellets from the second conveyor belt to the screening device; The third conveyor belt, located below the screening device, is used to transport waste materials smaller than a set size from the screening device to the mixing chamber of the first twin-shaft mixer.

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