Method for producing sintered ore with thickness of sintered material layer being 980 mm

Abstract

The invention relates to the technical field of ironmaking, in particular to a method for producing sintered ore with the thickness of a sintered material layer being 980 mm. The method comprises the steps that firstly, sintering raw materials are prepared; step 2, mixing and granulating; step 3, material distribution of a bedding material layer; 4, sintering mixture layer material distribution; 5, ignition is conducted; step 6, sintering; seventhly, ring cooling is conducted; and step 8, screening. By regulating and controlling the components and the proportion of the sintering raw materials and the process parameters of each process in the sinter production process, the solid fuel consumption and the return mine rate are reduced on the premise of not additionally increasing process equipment, and the yield of the sinter is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of ironmaking, and in particular to a method for producing sintered ore with a sintering material layer thickness of 980 mm. Background Art

[0002] Sintered ore is a crucial raw material for blast furnace ironmaking. It not only provides the iron source but also improves the furnace's air permeability and regulates the slag's alkalinity and fluidity. Sintered ore production involves mixing and granulating iron-containing ores, such as fine ore or concentrate, with appropriate amounts of fuel, flux, return ore, and water. After this, a series of physical and chemical changes occur on sintering equipment, ultimately forming a massive, artificially rich ore.

[0003] Sintering raw materials (including primary and auxiliary materials) typically come from multiple sources or batches, with significant compositional fluctuations and poor assimilation properties. This results in a decrease in sinter yield and deterioration in process specifications. This decrease in sinter yield leads to an increase in return ore flow, which not only severely restricts the smooth and efficient production of finished sintered ore but also increases process energy consumption and production costs. Thick-bed sintering facilitates the self-heating properties of the bed, promoting the formation of high-strength, reducible acicular calcium ferrite. This intensifies the sintering process, improves sintered ore quality, reduces return ore and fuel consumption, and ensures stable and high-quality sinter production.

[0004] Chinese patent CN115058589A discloses a method for producing sintered ore that achieves a sintering machine with a material distribution thickness of 950mm-1000mm. This method sprays hot steam at a temperature of approximately 200°C onto the mixture in a mixing trough to raise the material temperature, achieving thick layer sintering of 950mm-1000mm. However, this method fails to uniformly heat the material, maintains the sintering material temperature for a short time, and has limited practical production effectiveness. The steam easily causes the material to adhere to the mixing trough itself, resulting in uneven distribution, and requires the installation of an additional high-temperature heat source system. Chinese patent CN114574691A discloses a method for sintering ultra-thick layers to reduce pollutant emissions. This method achieves ultra-thick layer sintering by preparing two iron ore powders with low assimilation temperatures. However, this method requires two independent batching, distribution, and ignition sintering steps, resulting in a complex process flow, high equipment investment, and high production and operation requirements. Summary of the Invention

[0005] In response to the technical problems of uneven material distribution, inability to uniformly heat the materials, large equipment investment and complex process flow in the existing thick-bed sintering method, the present invention provides a sintered ore production method with a sintered material layer thickness of 980 mm. By regulating the components and ratios of the sintering raw materials and the process parameters of each process in the sintered ore production process, the solid fuel consumption and return ore rate are reduced, and the yield of the sintered ore is improved without adding additional process equipment.

[0006] The technical solutions of the present invention are as follows: A method for producing sintered ore with a sintering material layer thickness of 980 mm comprises the following steps: Step 1: Prepare sintering raw materials. In terms of mass percentage, the sintering raw materials include the following components: mixed material 56%-61%, coal powder 3.2%-3.6%, internal return ore 18%-21%, high return ore 5%-8%, quicklime 5%-7%, and limestone 3.5%-5.0%; Step 2: Mixing and granulating: using a primary mixer and a secondary mixer to prepare a sintered mixture from the sintered raw materials in step 1, wherein the average particle size of the sintered mixture is 3.85-4.1 mm; Step 3: Lay the bottom material layer. The bottom material uses internal return ore with a particle size of 12-18 mm. Lay the bottom material on the grate bed of the sintering machine trolley to build the bottom material layer. The laying height of the bottom material layer is 80-90 mm. Step 4: Spreading the sintering mixture layer. Use the combined spreading system to evenly spread the sintering mixture on the upper part of the base material layer to build the sintering mixture layer. The combined spreading system includes, in the order of use, a shuttle-type spreading trolley, a small ore chute, a hinged door, a round roller, eleven rollers, a plate-type flattening device, a pressure roller, and a flattening net. Step 5: Ignition, using double-row jet ignition, ignition gas flow rate is 2500-2600Nm³ / h, ignition air flow rate is 9500-10000Nm³ / h, ignition time is 85-90s, ignition depth is 19-24mm, ignition temperature is 1050±50℃; Step 6: Sintering: Control the sintering machine trolley speed at 1.85-2.15 m / min and the final temperature at 400-440°C to obtain a sintered cake after sintering. Step 7: Annular cooling: the sintered cake is cooled by blast cooling using an annular cooler. The temperature of the sintered cake after annular cooling is 40-90°C. Step 8: The sintered cake after ring cooling is screened three times in succession to obtain sintered ore.

[0007] Furthermore, in step one, the mixed material includes the following components in mass percentage: card powder 10.8%-11.06%, Minas fine powder 4.98%-4.99%, Haijun fine powder 2.82%-3.52%, Silk Road powder 13.06%-13.3%, Yangdi powder 13.05%-13.8%, Ba coarse ore dressing concentrate 1.13%-1.52%, super special powder 10.00%-12.06%, lump ore undersize powder 5.51%-5.65%, ball return powder 0.18%-0.33%, PB powder 5.06%-6.04%, iron oxide scale 1.57%-1.62%, steel fine powder 1.13%-1.31%, dust removal ash 4.21%-4.41%, high return 0.21%-0.30%, and medium silicon Ba coarse 22.58%-22.7%.

[0008] Furthermore, in step one, in the pulverized coal, the mass proportion of pulverized coal with a particle size of ≤3mm is 79%±2%, and the mass proportion of moisture is 3%-4.5%; the particle size of the internal return ore is <5mm; in the high return ore, the mass proportion of the high return ore with a particle size of >5mm is 24%-27%; the activity of quicklime is 310-350mol; in the limestone, the mass proportion of the limestone with a particle size of ≥3mm is ≥90%.

[0009] Furthermore, in step 2, the amount of water added to the mixer is 27-29m 3 / h, the mixing time of the primary mixer is 4-4.5min; the water addition amount of the secondary mixer is 2.2-2.5m 3 / h, and the granulation time of the secondary mixer is 4-4.5min. Both the primary mixer and the secondary mixer are cylindrical mixers. The main function of the primary mixer is to mix the sintering raw materials evenly, and the main function of the secondary mixer is to granulate the evenly mixed sintering raw materials.

[0010] Furthermore, in step 2, in the sintered mixture, the mass proportion of the sintered mixture with a particle size of less than 1 mm is 7.18%-9.89%, the mass proportion of the sintered mixture with a particle size of 1-3 mm is 31.9%-36.61%, the mass proportion of the sintered mixture with a particle size of 3-5 mm is 21.94%-23.56%, the mass proportion of the sintered mixture with a particle size of 5-8 mm is 25.57%-27.74%, and the mass proportion of the sintered mixture with a particle size of >8 mm is 7.3%-9.61%.

[0011] Furthermore, in step 4, the shuttle-type distribution trolley adopts a reciprocating distribution method. Based on the particle size segregation of the sinter mix and the movement trend of the sinter mix as it falls into the small hopper, the shuttle-type distribution trolley has a fixed distribution time of 3.5-4 seconds at the front stop and 7.5-8 seconds at the rear stop. This ensures that the shuttle-type distribution trolley distributes the sinter mix to the edges of the small hopper, ensuring that the material level in the small hopper is approximately horizontal and reducing the horizontal and vertical particle size segregation of the sinter mix in the small hopper. The surface of the small hopper is made of ceramic lining material to prevent uneven distribution of the sinter mix in the lateral direction of the sintering machine trolley due to the sinter mix sticking to the small hopper.

[0012] Furthermore, in step 4, the number of hinged doors is eight, and the eight hinged doors are independent of each other, and can locally adjust the material distribution to facilitate local control of the thickness of the sintering mixture layer. The opening range of each hinged door is 0-50mm, and a U-shaped gradient material distribution is adopted. The opening of the hinged door increases from the middle of the sintering machine trolley to the sides of the sintering machine trolley. The difference between the material distribution thickness at the edges of the sintering machine trolley and the material distribution thickness in the middle of the sintering machine trolley is 20mm, thereby reducing the edge effect of the sintering machine trolley and making the material surface of the entire sintering machine trolley uniform in air permeability. After the eight hinged doors are used for distribution, the thickness of the sintering mixture layer on the sintering machine trolley is 990mm, 985mm, 975mm, 970mm, 970mm, 975mm, 985mm, and 990mm from one edge to the other along the length direction of the sintering machine trolley. The roller skin is made of ceramic material, and the roller body is not easy to stick to the material, which can achieve smooth conveying of the sintered mixture. The moisture content of the sintered mixture at the roller is 6.9wt%±0.20wt%, and the material temperature of the sintered mixture at the roller is 38-48℃.

[0013] Furthermore, in step 4, the gap between the eleven rollers is controlled at 3-4 mm. From top to bottom, the gap between the first to sixth rollers is 3-3.5 mm, and the gap between the sixth to eleventh rollers is 3.5-4 mm. The eleven rollers are arranged at a 41.5° angle and operate at a frequency of 45 Hz. As they rotate, each roller distributes the sintered mix in a segregated manner, with large particles (3.5-4 mm in size) segregated to the bottom of the sintered mix layer and small particles (3-3.5 mm in size) segregated to the top, achieving layered distribution. A plate leveler smoothes the topmost uneven surface of the sintered mix layer created by the eleven rollers, ensuring smoothness across the entire surface. The pressing roller is used to press the material, effectively and evenly compacting the sintering mixture layer. The pressing depth is controlled at 40-50mm, which helps improve the density of the sintering mixture layer and enhance the sintering process. The flattening screen is used to smooth out the "fish scale" marks formed on the material surface after pressing, ensuring uniform ignition and enhancing the ignition process. The flattening screen is preferably a perforated wire mesh with a pore size of 10mm.

[0014] Furthermore, 29 bellows are installed at the bottom of the sintering machine trolley to transmit the negative pressure air required for sintering production. The 29 bellows are arranged on both sides in a double-suction style. Starting from the head of the sintering machine and along the running direction of the sintering machine trolley, the 29 bellows are numbered as bellows 1#, 2#, 3#, 4#, 5#, 6#, 7#, 8#, 9#, 10#, 11#, 12#, 13#, 14#, 15#, 16#, 17#, 18#, 19#, 20#, 21#, 22#, 23#, 24#, 25#, 26#, 27#, 28#, and 29#. During the sintering process, a partial extraction adjustment mode is used. The negative pressure air in the main flue on one side of the sintering machine is connected to the 1#-11# windbox and the 26#-29# windbox, respectively, to control the sintering negative pressure of the trolley-loaded material layer at the head and tail of the sintering machine. The negative pressure air in the main flue on the other side of the sintering machine is connected to the 12#-26# windbox to control the sintering negative pressure of the trolley-loaded material layer in the middle of the sintering machine. Under the action of the negative pressure air, the material layer above the sintering machine trolley completes the top-down sintering process, establishing a sintering temperature field. The sintering endpoint of the entire sintered mixture layer hits the 28# wind box, the temperature of the large flue is controlled at 140-175℃, and the working negative pressure of the large flue is controlled at 14-17KPa. By controlling the vertical combustion speed of the sintered mixture layer at 16-18mm / min, the sensible heat is transferred to the ring cooler, thereby improving the waste heat power generation efficiency and reducing the burning of the grate bars.

[0015] Furthermore, in step eight, the screen gap used for the first screening is 20 mm, the screen gap used for the second screening is 12 mm, and the screen gap used for the third screening is 5 mm. In terms of mass percentage, the particle size composition of the sintered ore after screening is as follows: 6.09%-9.76% of sintered ore with a particle size greater than 40 mm, 11.22%-20.39% of sintered ore with a particle size of 25-40 mm, 24.12%-27.81% of sintered ore with a particle size of 16-25 mm, 18.25%-25.05% of sintered ore with a particle size of 10-16 mm, 23.2%-23.98% of sintered ore with a particle size of 5-10 mm, and 4.27%-5.87% of sintered ore with a particle size less than 5 mm. Among them, the sintered ore with a particle size less than 5 mm can be used as the internal return ore in step one to participate in the preparation of sintering raw materials.

[0016] The beneficial effects of the present invention are: The present invention provides a sintered ore production method that can achieve a sintered material layer thickness of 980 mm. By regulating the process parameters of each process in the sintering production process, U-shaped gradient distribution and equal pressure sintering are promoted to make the air permeability of the material surface uniform, which is beneficial to improving the ignition uniformity and strengthening the ignition process, thereby achieving the sintering of an ultra-thick material layer with an average thickness of 980 mm.

[0017] A "six stabilizations and one control" production process method of "stabilizing the moisture content of sintering raw materials, stabilizing the carbon content of sintering raw materials, stabilizing the fuel structure, stabilizing the fuel particle size, stabilizing the flux quality, stabilizing the equipment function, and controlling the end point position" has been constructed. It stabilizes the sintering process of ultra-thick material layers, has strong operability in actual production, reduces solid fuel consumption and return ore rate without adding additional process equipment, improves the quality indicators of sintered ore while increasing the finished product rate of sintered ore, has good practical application effects and promotion value, and achieves the effects of improving the quality and output of sintered ore and increasing green and low-carbon production of material lines. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the scope of protection of the present invention.

[0019] Example 1 A method for producing sintered ore with a sintering material layer thickness of 980 mm comprises the following steps: Step 1: Prepare sintering raw materials. In terms of mass percentage, the sintering raw materials include the following components: mixed material 60.5%, coal powder 3.3%, internal return ore 19.5%, high return ore 7.5%, quicklime 5.2%, activity of 327 mol; limestone 4.0%.

[0020] In terms of mass percentage, the mixed material includes the following components: Ka powder 10.97%, Minas fine powder 4.98%, Haijun fine powder 3.41%, Silk Road powder 13.19%, Yangdi powder 13.72%, Ba coarse ore dressing fine powder 1.33%, super special powder 10.69%, lump ore undersize powder 5.60%, ball return powder 0.23%, PB powder 5.85%, iron oxide scale 1.61%, steel fine powder 1.26%, dust removal ash 4.26%, high return 0.25%, and medium silicon Ba coarse 22.65%.

[0021] Among the coal powder, the mass proportion of coal powder with a particle size of ≤3mm is 79%, and the mass proportion of water is 4.3%; the particle size of the internal return ore is <5mm; among the high return ore, the mass proportion of the high return ore with a particle size of >5mm is 25.2%; the activity of quicklime is 327mol; among the limestone, the mass proportion of the limestone with a particle size of ≥3mm is 90%.

[0022] Step 2: Mixing and granulation, use the primary mixer and the secondary mixer to make the sintering raw materials in step 1 into sintering mixture, the average particle size of the sintering mixture is 3.85-4.1mm. The water addition amount of the primary mixer is 27-29m 3 / h, the mixing time of the primary mixer is 4-4.5min; the water addition amount of the secondary mixer is 2.2-2.5m 3 / h, and the granulation time of the secondary mixer is 4-4.5min. Both the primary mixer and the secondary mixer are cylindrical mixers. The main function of the primary mixer is to mix the sintering raw materials evenly, and the main function of the secondary mixer is to granulate the evenly mixed sintering raw materials.

[0023] Among the sintering mixtures, the mass proportion of sintering mixtures with particle size <1mm is 7.18%-9.89%, the mass proportion of sintering mixtures with particle size of 1-3mm is 31.9%-36.61%, the mass proportion of sintering mixtures with particle size of 3-5mm is 21.94%-23.56%, the mass proportion of sintering mixtures with particle size of 5-8mm is 25.57%-27.74%, and the mass proportion of sintering mixtures with particle size >8mm is 7.3%-9.61%.

[0024] Step 3: Lay the bottom material layer. The bottom material uses internal return ore with a particle size of 12-18 mm. The bottom material is transported to the bottom material hopper by the feeding belt 1, and then directly spread to the grate bed of the sintering machine trolley by the bottom material hopper to build the bottom material layer. The laying height of the bottom material layer is 90 mm.

[0025] Step 4: Distribute the sinter mix layer. Use a combined distribution system to evenly distribute the sinter mix on top of the base material layer to build the sinter mix layer. The combined distribution system, in order of use, includes a shuttle distribution trolley, a small chute, a hinged door, a round roller, eleven rollers, a plate leveler, a pressure roller, and a flattening net. The feed belt 2 conveys the sinter mix to the shuttle distribution trolley, which moves back and forth above the small chute, evenly distributing the sinter mix within the chute. The hinged door below the small chute is adjusted to open, unloading the sinter mix onto the round roller. The round roller then conveys the sinter mix to the eleven rollers. The eleven rollers distribute the sinter mix to the top of the base material layer. The plate leveler, pressure roller, and flattening net are then used to distribute the mix, building the sinter mix layer.

[0026] The shuttle-type distribution trolley adopts a reciprocating distribution method. According to the particle size segregation of the sintered mixture and the movement trend of the sintered mixture falling to the small ore trough, the fixed-point distribution time of the shuttle-type distribution trolley at the front dead point is 3.5-4s, and the fixed-point distribution time of the shuttle-type distribution trolley at the rear dead point is 7.5-8s.

[0027] The surface of the small ore trough is made of ceramic lining material.

[0028] There are eight independent hinged doors, allowing for local adjustment of material distribution. Each door has an opening range of 0-50mm, utilizing a U-shaped gradient material distribution system. The door opening increases from the center of the sintering trolley toward the sides, and the difference in material distribution thickness between the edges and the center of the trolley is 20mm. After distribution through the eight hinged doors, the thickness of the sinter mix layer on the trolley, from one edge to the other, is 990mm, 985mm, 975mm, 970mm, 970mm, 975mm, 985mm, and finally 990mm along the length of the trolley.

[0029] The roller skin of the round roller is made of ceramic material, the moisture content of the sintered mixture at the round roller is 6.9wt%±0.20wt%, and the material temperature of the sintered mixture at the round roller is 38-48°C.

[0030] The gap between the eleven rollers is controlled at 3-4mm. From top to bottom, the gap between the first to sixth rollers is 3-3.5mm, and the gap between the sixth and eleventh rollers is 3.5-4mm. The rollers are arranged at a 41.5° angle and operate at a frequency of 45Hz. As they rotate, the rollers distribute the sintering mix in a segregated manner, with large particles (3.5-4mm in size) being distributed to the bottom of the mix layer, while smaller particles (3-3.5mm in size) are distributed to the top, achieving layered distribution.

[0031] The plate leveler is used to smooth out the top concave and convex surface of the sintered mixed material layer produced by eleven rollers, so as to achieve flatness control of the entire material surface.

[0032] The pressing roller is used to press the material, which can effectively press the sintering mixed material layer, and the pressing depth is controlled at 40-50mm.

[0033] The flattening mesh is used to smooth out the "fish scale pattern" formed on the material surface after pressing, achieving uniform ignition of the material surface and enhancing the ignition process. The flattening mesh is preferably a perforated wire mesh with a pore size of 10mm.

[0034] Step 5: Ignition: After placing the sintering mix onto the sintering machine trolley with an average thickness of 980mm, ignition is performed. Double-row jet ignition is used, with an ignition gas flow rate of 2500-2600Nm³ / h, an ignition air flow rate of 9500-10000Nm³ / h, an ignition time of 85-90s, an ignition depth of 19-24mm, and an ignition temperature of 1070°C.

[0035] Step 6: Sintering: The sintering machine trolley speed is controlled at 1.92 m / min, and the final temperature is controlled at 400-440°C. After sintering, a sintered cake is obtained. After ignition, ventilation begins. Twenty-nine bellows are installed at the bottom of the sintering machine trolley, arranged on both sides in a double-suction style. Starting from the head of the sintering machine, along the running direction of the sintering machine trolley, the twenty-nine bellows are numbered in sequence as 1# bellows, 2# bellows, 3# bellows, 4# bellows, 5# bellows, 6# bellows, 7# bellows, 8# bellows, 9# bellows, 10# bellows, 11# bellows, 12# bellows, 13# bellows, 14# bellows, 15# bellows, 16# bellows, 17# bellows, 18# bellows, 19# bellows, 20# bellows, 21# bellows, 22# bellows, 23# bellows, 24# bellows, 25# bellows, 26# bellows, 27# bellows, 28# bellows, and 29# bellows. During the sintering production process, a partial extraction adjustment mode is adopted. The negative pressure air in the large flue on one side of the sintering machine is connected to the 1#-11# windbox and the 26#-29# windbox respectively to control the sintering negative pressure of the trolley-loaded material layer at the head of the sintering machine and the trolley-loaded material layer at the tail of the sintering machine. The negative pressure air in the large flue on the other side of the sintering machine is connected to the 12#-26# windbox to control the sintering negative pressure of the trolley-loaded material layer in the middle of the sintering machine. As the sintering process progresses, the sintering endpoint of the entire sintering mixture layer hits the 28# windbox, and the observed sintering endpoint temperature is 427℃. The temperature of the large flue is controlled at 140-175℃, and the working negative pressure of the large flue is controlled at around 15.2KPa. The vertical combustion speed of the sintering mixture layer is controlled at 16-18mm / min.

[0036] Step 7: Circular Cooling: After sintering, the sintered cake is unloaded at the end of the sintering machine and crushed by a single roller. It is then transferred through a hot ore chute to a circular cooler for circular cooling. The sintered ore is cooled by blast air in the circular cooler, and the temperature of the sintered ore after circular cooling is 40-90°C.

[0037] Step 8: The sintered cake after ring cooling is screened three times in succession to obtain sintered ore. Among them, the screen gap used in the first screening is 20mm, the screen gap used in the second screening is 12mm, and the screen gap used in the third screening is 5mm. In terms of mass percentage, the particle size composition of the sintered ore after screening is as follows: 9.7% of sintered ore with a particle size of >40mm, 15.47% of sintered ore with a particle size of 25-40mm, 24.12% of sintered ore with a particle size of 16-25mm, 22.76% of sintered ore with a particle size of 10-16mm, 23.5% of sintered ore with a particle size of 5-10mm, and 4.45% of sintered ore with a particle size of <5mm. Among them, the sintered ore with a particle size of <5mm can be used as the internal return ore in step 1 to participate in the preparation of sintering raw materials.

[0038] The performance indicators of the sintered ore produced by the method provided in this embodiment are: finished product rate of 79.2%, drum strength of 83.7%, average basicity of 1.91, return rate of ore <20.9%, solid fuel consumption of 48.65 kg / t, and sintering machine utilization coefficient of 1.20 t / m 2 h.

[0039] Example 2 A method for producing sintered ore with a sintering material layer thickness of 980 mm comprises the following steps: Step 1: Prepare sintering raw materials. In terms of mass percentage, the sintering raw materials include the following components: mixed material 60.7%, coal powder 3.4%, internal return ore 19.8%, high return ore 7%, quicklime 5.2%, activity of 328 mol; limestone 3.9%.

[0040] In terms of mass percentage, the mixed material includes the following components: Ka powder 10.85%, Minas fine powder 4.98%, Haijun fine powder 3.2%, Silk Road powder 13.26%, Yangdi powder 13.65%, Ba coarse ore dressing fine powder 1.58%, super special powder 11.49%, lump ore undersize powder 5.55%, ball return powder 0.26%, PB powder 5.17%, iron oxide scale 1.6%, steel fine powder 1.3%, dust removal ash 4.22%, high return 0.28%, and medium silicon Ba coarse 22.61%.

[0041] Among the pulverized coal, the mass proportion of pulverized coal with a particle size of ≤3mm is 79%, and the mass proportion of moisture is 4.3%; the particle size of the internal return ore is <5mm; among the high return ore, the mass proportion of the high return ore with a particle size of >5mm is 24.5%; the activity of quicklime is 328mol; among the limestone, the mass proportion of the limestone with a particle size of ≥3mm is 92%.

[0042] Step 2: Mixing and granulation, use the primary mixer and the secondary mixer to make the sintering raw materials in step 1 into sintering mixture, the average particle size of the sintering mixture is 3.85-4.1mm. The water addition amount of the primary mixer is 27-29m 3 / h, the mixing time of the primary mixer is 4-4.5min; the water addition amount of the secondary mixer is 2.2-2.5m 3 / h, and the granulation time of the secondary mixer is 4-4.5min. Both the primary mixer and the secondary mixer are cylindrical mixers. The main function of the primary mixer is to mix the sintering raw materials evenly, and the main function of the secondary mixer is to granulate the evenly mixed sintering raw materials.

[0043] Among the sintering mixtures, the mass proportion of sintering mixtures with particle size <1mm is 7.18%-9.89%, the mass proportion of sintering mixtures with particle size of 1-3mm is 31.9%-36.61%, the mass proportion of sintering mixtures with particle size of 3-5mm is 21.94%-23.56%, the mass proportion of sintering mixtures with particle size of 5-8mm is 25.57%-27.74%, and the mass proportion of sintering mixtures with particle size >8mm is 7.3%-9.61%.

[0044] Step 3: Lay the bottom material layer. The bottom material uses internal return ore with a particle size of 12-18 mm. The bottom material is transported to the bottom material hopper by the feeding belt 1, and then directly spread to the grate bed of the sintering machine trolley by the bottom material hopper to build the bottom material layer. The laying height of the bottom material layer is 90 mm.

[0045] Step 4: Distribute the sinter mix layer. Use a combined distribution system to evenly distribute the sinter mix on top of the base material layer to build the sinter mix layer. The combined distribution system, in order of use, includes a shuttle distribution trolley, a small chute, a hinged door, a round roller, eleven rollers, a plate leveler, a pressure roller, and a flattening net. The feed belt 2 conveys the sinter mix to the shuttle distribution trolley, which moves back and forth above the small chute, evenly distributing the sinter mix within the chute. The hinged door below the small chute is adjusted to open, unloading the sinter mix onto the round roller. The round roller then conveys the sinter mix to the eleven rollers. The eleven rollers distribute the sinter mix to the top of the base material layer. The plate leveler, pressure roller, and flattening net are then used to distribute the mix, building the sinter mix layer.

[0046] The shuttle-type distribution trolley adopts a reciprocating distribution method. According to the particle size segregation of the sintered mixture and the movement trend of the sintered mixture falling to the small ore trough, the fixed-point distribution time of the shuttle-type distribution trolley at the front dead point is 3.5-4s, and the fixed-point distribution time of the shuttle-type distribution trolley at the rear dead point is 7.5-8s.

[0047] The surface of the small ore trough is made of ceramic lining material.

[0048] There are eight independent hinged doors, allowing for local adjustment of material distribution. Each door has an opening range of 0-50mm, utilizing a U-shaped gradient material distribution system. The door opening increases from the center of the sintering trolley toward the sides, and the difference in material distribution thickness between the edges and the center of the trolley is 20mm. After distribution through the eight hinged doors, the thickness of the sinter mix layer on the trolley, from one edge to the other, is 990mm, 985mm, 975mm, 970mm, 970mm, 975mm, 985mm, and finally 990mm along the length of the trolley.

[0049] The roller skin of the round roller is made of ceramic material, the moisture content of the sintered mixture at the round roller is 6.9wt%±0.20wt%, and the material temperature of the sintered mixture at the round roller is 38-48°C.

[0050] The gap between the eleven rollers is controlled at 3-4mm. From top to bottom, the gap between the first to sixth rollers is 3-3.5mm, and the gap between the sixth and eleventh rollers is 3.5-4mm. The rollers are arranged at a 41.5° angle and operate at a frequency of 45Hz. As they rotate, the rollers distribute the sintering mix in a segregated manner, with large particles (3.5-4mm in size) being distributed to the bottom of the mix layer, while smaller particles (3-3.5mm in size) are distributed to the top, achieving layered distribution.

[0051] The plate leveler is used to smooth out the top concave and convex surface of the sintered mixed material layer produced by eleven rollers, so as to achieve flatness control of the entire material surface.

[0052] The pressing roller is used to press the material, which can effectively press the sintering mixed material layer, and the pressing depth is controlled at 40-50mm.

[0053] The flattening mesh is used to smooth out the "fish scale pattern" formed on the material surface after pressing, achieving uniform ignition of the material surface and enhancing the ignition process. The flattening mesh is preferably a perforated wire mesh with a pore size of 10mm.

[0054] Step 5: Ignition: After placing the sintering mix onto the sintering machine trolley with an average thickness of 980mm, ignition is performed. Double-row jet ignition is used, with an ignition gas flow rate of 2500-2600Nm³ / h, an ignition air flow rate of 9500-10000Nm³ / h, an ignition time of 85-90 seconds, an ignition depth of 19-24mm, and an ignition temperature of 1082°C.

[0055] Step 6: Sintering: The sintering machine trolley speed is controlled at 1.92 m / min, and the final temperature is controlled at 400-440°C. After sintering, a sintered cake is obtained. After ignition, ventilation begins. Twenty-nine bellows are installed at the bottom of the sintering machine trolley, arranged on both sides in a double-suction style. Starting from the head of the sintering machine, along the running direction of the sintering machine trolley, the twenty-nine bellows are numbered in sequence as 1# bellows, 2# bellows, 3# bellows, 4# bellows, 5# bellows, 6# bellows, 7# bellows, 8# bellows, 9# bellows, 10# bellows, 11# bellows, 12# bellows, 13# bellows, 14# bellows, 15# bellows, 16# bellows, 17# bellows, 18# bellows, 19# bellows, 20# bellows, 21# bellows, 22# bellows, 23# bellows, 24# bellows, 25# bellows, 26# bellows, 27# bellows, 28# bellows, and 29# bellows. During the sintering production process, a partial extraction adjustment mode is adopted. The negative pressure air in the large flue on one side of the sintering machine is connected to the 1#-11# windbox and the 26#-29# windbox respectively to control the sintering negative pressure of the trolley-loaded material layer at the head of the sintering machine and the trolley-loaded material layer at the tail of the sintering machine; the negative pressure air in the large flue on the other side of the sintering machine is connected to the 12#-26# windbox to control the sintering negative pressure of the trolley-loaded material layer in the middle of the sintering machine. As the sintering process progresses, the sintering endpoint of the entire sintering mixture layer hits the 28# windbox, and the observed sintering endpoint temperature is 438℃. The temperature of the large flue is controlled at 140-175℃, and the working negative pressure of the large flue is controlled at around 15.57KPa. The vertical combustion speed of the sintering mixture layer is controlled at 16-18mm / min.

[0056] Step 7: Circular Cooling: After sintering, the sintered cake is unloaded at the end of the sintering machine and crushed by a single roller. It is then transferred through a hot ore chute to a circular cooler for circular cooling. The sintered ore is cooled by blast air in the circular cooler, and the temperature of the sintered ore after circular cooling is 40-90°C.

[0057] Step 8: The sintered cake after ring cooling is screened three times in succession to obtain sintered ore. The screen gap used in the first screening is 20mm, the screen gap used in the second screening is 12mm, and the screen gap used in the third screening is 5mm. In terms of mass percentage, the particle size composition of the sintered ore after screening is as follows: 8.49% of sintered ore with a particle size of >40mm, 16.32% of sintered ore with a particle size of 25-40mm, 24.95% of sintered ore with a particle size of 16-25mm, 22.59% of sintered ore with a particle size of 10-16mm, 23.24% of sintered ore with a particle size of 5-10mm, and 4.41% of sintered ore with a particle size of <5mm. Among them, the sintered ore with a particle size of <5mm can be used as the internal return ore in step 1 to participate in the preparation of sintering raw materials.

[0058] The performance indicators of the sintered ore produced by the method provided in this embodiment are: finished product rate of 78.9%, drum strength of 83.3%, average basicity of 1.91, return rate of ore <20.5%, solid fuel consumption of 48.02 kg / t, and sintering machine utilization coefficient of 1.20 t / m 2 h.

[0059] Comparative Example 1 A method for producing sintered ore with a sintering material layer thickness of 940 mm comprises the following steps: Step 1: Prepare sintering raw materials. In terms of mass percentage, the sintering raw materials include the following components: mixed material 60.15%, coal powder 3.65%, internal return ore 17.5%, high return ore 9.5%, quicklime 4.1%, activity of 327 mol; limestone 5.1%.

[0060] In terms of mass percentage, the mixed material includes the following components: Ka powder 10.6%, Minas fine powder 0.97%, Kulan powder 2.68%, FMG mixed powder 14.08%, Silk Road powder 11.59%, Yangdi powder 9.47%, Ba coarse ore dressing concentrate 2.37%, super special powder 5.58%, lump ore undersize powder 6.83%, ball return powder 0.14%, Newman powder 7.24%, iron oxide scale 1.43%, steel fine powder 1.24%, dust removal ash 4.01%, high return 0.18%, and medium silicon Ba coarse 21.59%.

[0061] Among the coal powder, the mass proportion of coal powder with a particle size of ≤3mm is 79%, and the mass proportion of water is 4.3%; the particle size of the internal return ore is <5mm; among the high return ore, the mass proportion of the high return ore with a particle size of >5mm is 25.2%; the activity of quicklime is 327mol; among the limestone, the mass proportion of the limestone with a particle size of ≥3mm is 90%.

[0062] Step 2: Mixing and granulation, use the primary mixer and the secondary mixer to make the sintering raw materials in step 1 into sintering mixture, the average particle size of the sintering mixture is 3.85-4.1mm. The water addition amount of the primary mixer is 27-29m 3 / h, the mixing time of the primary mixer is 4-4.5min; the water addition amount of the secondary mixer is 2.2-2.5m 3 / h, and the granulation time of the secondary mixer is 4-4.5min. Both the primary mixer and the secondary mixer are cylindrical mixers. The main function of the primary mixer is to mix the sintering raw materials evenly, and the main function of the secondary mixer is to granulate the evenly mixed sintering raw materials.

[0063] Among the sintering mixtures, the mass proportion of sintering mixtures with particle size <1mm is 7.53%-10.11%, the mass proportion of sintering mixtures with particle size of 1-3mm is 30.31%-35.37%, the mass proportion of sintering mixtures with particle size of 3-5mm is 20.75%-22.78%, the mass proportion of sintering mixtures with particle size of 5-8mm is 23.69%-26.93%, and the mass proportion of sintering mixtures with particle size >8mm is 6.96%-9.52%.

[0064] Step 3: Lay the bottom material layer. The bottom material uses internal return ore with a particle size of 12-18 mm. The bottom material is transported to the bottom material hopper by the feeding belt 1, and then directly spread to the grate bed of the sintering machine trolley by the bottom material hopper to build the bottom material layer. The laying height of the bottom material layer is 90 mm.

[0065] Step 4: Distribute the sinter mix layer. Use a combined distribution system to evenly distribute the sinter mix on top of the base material layer to build the sinter mix layer. The combined distribution system, in order of use, includes a shuttle distribution trolley, a small chute, a hinged door, a round roller, eleven rollers, a plate leveler, a pressure roller, and a flattening net. The feed belt 2 conveys the sinter mix to the shuttle distribution trolley, which moves back and forth above the small chute, evenly distributing the sinter mix within the chute. The hinged door below the small chute is adjusted to open, unloading the sinter mix onto the round roller. The round roller then conveys the sinter mix to the eleven rollers. The eleven rollers distribute the sinter mix to the top of the base material layer. The plate leveler, pressure roller, and flattening net are then used to distribute the mix, building the sinter mix layer.

[0066] The shuttle-type distribution trolley adopts a reciprocating distribution method. According to the particle size segregation of the sintered mixture and the movement trend of the sintered mixture falling to the small ore trough, the fixed-point distribution time of the shuttle-type distribution trolley at the front dead point is 3.5-4s, and the fixed-point distribution time of the shuttle-type distribution trolley at the rear dead point is 7.5-8s.

[0067] The surface of the small ore trough is made of ceramic lining material.

[0068] There are eight independent hinged doors, allowing for localized material distribution adjustments. Each door has an opening range of 0-50mm, ensuring uniform material distribution. After distribution through the eight hinged doors, the thickness of the sinter mix layer on the sintering machine trolley is 940mm from edge to edge along the length of the trolley.

[0069] The roller skin of the round roller is made of ceramic material, the moisture content of the sintered mixture at the round roller is 6.9wt%±0.20wt%, and the material temperature of the sintered mixture at the round roller is 38-48°C.

[0070] The gap between the eleven rollers is controlled at 3-4mm. From top to bottom, the gap between the first to sixth rollers is 3-3.5mm, and the gap between the sixth and eleventh rollers is 3.5-4mm. The rollers are arranged at a 41.5° angle and operate at a frequency of 45Hz. As they rotate, the rollers distribute the sintering mix in a segregated manner, with large particles (3.5-4mm in size) being distributed to the bottom of the mix layer, while smaller particles (3-3.5mm in size) are distributed to the top, achieving layered distribution.

[0071] The plate leveler is used to smooth out the top concave and convex surface of the sintered mixed material layer produced by eleven rollers, so as to achieve flatness control of the entire material surface.

[0072] The pressing roller is used to press the material, which can effectively press the sintering mixed material layer, and the pressing depth is controlled at 40-50mm.

[0073] The flattening mesh is used to smooth out the "fish scale pattern" formed on the material surface after pressing, achieving uniform ignition of the material surface and enhancing the ignition process. The flattening mesh is preferably a perforated wire mesh with a pore size of 10mm.

[0074] Step 5: Ignition: After placing the sintering mix onto the sintering machine trolley with an average thickness of 940mm, ignition is performed. Double-row jet ignition is used, with an ignition gas flow rate of 2500-2600Nm³ / h, an ignition air flow rate of 9500-10000Nm³ / h, an ignition time of 85-90s, an ignition depth of 19-24mm, and an ignition temperature of 1015°C.

[0075] Step 6: Sintering. The sintering machine trolley speed is controlled at 2.02 m / min, and the final temperature is controlled at 400-440°C. After sintering, a sintered cake is obtained. After ignition, ventilation begins. Twenty-nine bellows are installed at the bottom of the sintering machine trolley, arranged on both sides in a double-suction style. Starting from the head of the sintering machine, along the running direction of the sintering machine trolley, the twenty-nine bellows are numbered in sequence as 1# bellows, 2# bellows, 3# bellows, 4# bellows, 5# bellows, 6# bellows, 7# bellows, 8# bellows, 9# bellows, 10# bellows, 11# bellows, 12# bellows, 13# bellows, 14# bellows, 15# bellows, 16# bellows, 17# bellows, 18# bellows, 19# bellows, 20# bellows, 21# bellows, 22# bellows, 23# bellows, 24# bellows, 25# bellows, 26# bellows, 27# bellows, 28# bellows, and 29# bellows. During the sintering process, a partial extraction adjustment mode is used. The negative pressure air in the flue on one side of the sintering machine is connected to the 1#-11# windbox and the 26#-29# windbox, respectively, to control the sintering negative pressure of the trolley-loaded material layer at the head and tail of the sintering machine. The negative pressure air in the flue on the other side of the sintering machine is connected to the 12#-26# windbox to control the sintering negative pressure of the trolley-loaded material layer in the middle of the sintering machine. As the sintering process progresses, the sintering endpoint of the entire sintered mixed material layer hits the 27# windbox, and the observed sintering endpoint temperature is 392°C. The temperature of the flue is controlled at 140-175°C, and the working negative pressure of the flue is controlled at around 14.1KPa. The vertical combustion speed of the sintered mixed material layer is controlled at 16-18mm / min.

[0076] Step 7: Circular Cooling: After sintering, the sintered cake is unloaded at the end of the sintering machine and crushed by a single roller. It is then transferred through a hot ore chute to a circular cooler for circular cooling. The sintered ore is cooled by blast air in the circular cooler, and the temperature of the sintered ore after circular cooling is 40-90°C.

[0077] Step 8: The sintered cake after ring cooling is screened three times to obtain sintered ore. The screen gap used in the first screening is 20mm, the screen gap used in the second screening is 12mm, and the screen gap used in the third screening is 5mm. In terms of mass percentage, the particle size composition of the sintered ore after screening is as follows: 8.13% of sintered ore with a particle size greater than 40mm, 15.49% of sintered ore with a particle size of 25-40mm, 23.55% of sintered ore with a particle size of 16-25mm, 22.87% of sintered ore with a particle size of 10-16mm, 24.84% of sintered ore with a particle size of 5-10mm, and 5.12% of sintered ore with a particle size less than 5mm. Among them, the sintered ore with a particle size less than 5mm can be used as the internal return ore in step 1 to participate in the preparation of sintering raw materials.

[0078] The performance indicators of the sintered ore produced by the method provided in this comparative example are: finished product rate of 78.56%, drum strength of 82.6%, average basicity of 1.91, return rate of ore <21.3%, solid fuel consumption of 51.71kg / t, and sintering machine utilization coefficient of 1.17t / m 2 h.

[0079] Although the present invention has been described in detail by way of preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and substance of the present invention, persons of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and such modifications or substitutions shall be within the scope of the present invention. Any changes or substitutions that can be readily conceived by persons skilled in the art within the technical scope disclosed in the present invention shall be within the scope of protection of the present invention.

Claims

1. A method for producing sintered ore with a sintering material layer thickness of 980 mm, characterized in that: The steps include: Step 1: Prepare sintering raw materials. In terms of mass percentage, the sintering raw materials include the following components: mixed material 56%-61%, coal powder 3.2%-3.6%, internal return ore 18%-21%, high return ore 5%-8%, quicklime 5%-7%, and limestone 3.5%-5.0%; Step 2: Mixing and granulating: using a primary mixer and a secondary mixer to prepare a sintered mixture from the sintered raw materials in step 1, wherein the average particle size of the sintered mixture is 3.85-4.1 mm; Step 3: Lay the bottom material layer. The bottom material uses internal return ore with a particle size of 12-18 mm. Lay the bottom material on the grate bed of the sintering machine trolley to build the bottom material layer. The laying height of the bottom material layer is 80-90 mm. Step 4: Spreading the sintering mixture layer. Use the combined spreading system to evenly spread the sintering mixture on the upper part of the base material layer to build the sintering mixture layer. The combined spreading system includes, in the order of use, a shuttle-type spreading trolley, a small ore chute, a hinged door, a round roller, eleven rollers, a plate-type flattening device, a pressure roller, and a flattening net. Step 5: Ignition, using double-row jet ignition, ignition gas flow rate is 2500-2600Nm³ / h, ignition air flow rate is 9500-10000Nm³ / h, ignition time is 85-90s, ignition depth is 19-24mm, ignition temperature is 1050±50℃; Step 6: Sintering: Control the sintering machine trolley speed at 1.85-2.15 m / min and the final temperature at 400-440°C to obtain a sintered cake after sintering. Step 7: Annular cooling: the sintered cake is cooled by blast cooling using an annular cooler. The temperature of the sintered cake after annular cooling is 40-90°C. Step 8: The sintered cake after ring cooling is screened three times in succession to obtain sintered ore.

2. The method for producing sintered ore with a sintering material layer thickness of 980 mm according to claim 1, wherein: In step 1, the mixed material includes the following components by mass percentage: Ka powder 10.8%-11.06%, Minas refined powder 4.98%-4.99%, Haijun refined powder 2.82%-3.52%, Silk Road powder 13.06%-13.3%, Yangdi powder 13.05%-13.8%, Ba coarse ore dressing concentrate 1.13%-1.52%, super special powder 10.00%-12.06%, lump ore undersize powder 5.51%-5.65%, ball return powder 0.18%-0.33%, PB powder 5.06%-6.04%, iron oxide scale 1.57%-1.62%, steel concentrate 1.13%-1.31%, dust removal ash 4.21%-4.41%, high return 0.21%-0.30%, medium silicon Ba coarse 22.58%-22.7%.

3. The method for producing sintered ore with a sintering material layer thickness of 980 mm according to claim 1, wherein: In step 1, in the pulverized coal, the mass proportion of pulverized coal with a particle size of ≤3mm is 79%±2%, and the mass proportion of moisture is 3%-4.5%; the particle size of the internal return ore is <5mm; in the high return ore, the mass proportion of the high return ore with a particle size of >5mm is 24%-27%; the activity of quicklime is 310-350mol; in the limestone, the mass proportion of the limestone with a particle size of ≥3mm is ≥90%.

4. The method for producing sintered ore with a sintering material layer thickness of 980 mm according to claim 1, wherein: In step 2, the amount of water added to the mixer is 27-29m 3 / h, the mixing time of the primary mixer is 4-4.5min; the water addition amount of the secondary mixer is 2.2-2.5m 3 / h, and the granulation time of the secondary mixer is 4-4.5min.

5. The method for producing sintered ore with a sintering material layer thickness of 980 mm according to claim 1, wherein: In step 2, in the sintered mixture, the mass proportion of the sintered mixture with a particle size of less than 1 mm is 7.18%-9.89%, the mass proportion of the sintered mixture with a particle size of 1-3 mm is 31.9%-36.61%, the mass proportion of the sintered mixture with a particle size of 3-5 mm is 21.94%-23.56%, the mass proportion of the sintered mixture with a particle size of 5-8 mm is 25.57%-27.74%, and the mass proportion of the sintered mixture with a particle size of >8 mm is 7.3%-9.61%.

6. The method for producing sintered ore with a sintering material layer thickness of 980 mm according to claim 1, characterized in that: In step 4, the shuttle-type feeding trolley adopts a reciprocating feeding method. The fixed-point feeding time of the shuttle-type feeding trolley at the front dead point is 3.5-4s, and the fixed-point feeding time of the shuttle-type feeding trolley at the rear dead point is 7.5-8s.

7. The method for producing sintered ore with a sintering material layer thickness of 980 mm according to claim 1, characterized in that: In step 4, there are eight hinged doors, and the openings of the hinged doors increase from the middle of the sintering machine trolley to both sides of the sintering machine trolley.

8. The method for producing sintered ore with a sintering material layer thickness of 980 mm according to claim 1, characterized in that: In step 4, the gap between the eleven rollers is controlled at 3-4 mm. From top to bottom, the gap between the first roller to the sixth roller is 3-3.5 mm, and the gap between the sixth roller to the eleventh roller is 3.5-4 mm. The eleven rollers are set at a 41.5° incline, and the operating frequency is 45 Hz.

9. The method for producing sintered ore with a sintering material layer thickness of 980 mm according to claim 1, characterized in that: There are 29 bellows at the bottom of the sintering machine trolley, which are arranged on both sides in a double-suction style.

10. The method for producing sintered ore with a sintering material layer thickness of 980 mm according to claim 1, characterized in that: In step eight, the screen gap used in the first screening is 20 mm, the screen gap used in the second screening is 12 mm, and the screen gap used in the third screening is 5 mm.