Sintering system and method for pre-drying and strengthening high-proportion fine iron powder

Abstract

The sintering system comprises a sintering machine, the sintering machine is driven by transmission mechanisms arranged on a machine head and a machine tail, a material distributing machine is arranged at the input end of the sintering machine, and the output end of the material distributing machine is connected with the input end of the sintering machine; a crushing mechanism and a screening mechanism are arranged at the output end of the sintering machine, the input end of the crushing mechanism is connected with the output end of the distributing machine, and the input end of the screening mechanism is connected with the output end of the crushing mechanism; a drying unit is arranged between a material distributing machine and an ignition unit of the sintering machine, and sintering high-temperature waste gas is used for pre-drying a high-moisture granulation mixture. The drying unit is arranged between the material distributing machine and the ignition unit of the sintering machine, high-moisture granulation mixed materials are pre-dried through sintering high-temperature waste gas, on one hand, the temperature of a material layer can be increased, on the other hand, part of moisture is removed, moisture evaporation and heat absorption in the subsequent sintering process and formation of an over-wet zone at the bottom of the material layer are reduced, and the sintering efficiency is improved. Therefore, the air permeability in the sintering process is improved, sintering liquid phase consolidation is strengthened, and the sintering yield and quality are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of iron and steel metallurgy, and in particular to a sintering system and method for pre-drying and strengthening high-proportion iron concentrate. Background Art

[0002] The blast furnace-converter (BOF) long process remains the primary steel production process in my country, accounting for over 90% of steel production. High-basicity sinter, acidic pellets, and lump ore are the primary feedstocks for my country's blast furnaces, with high-basicity sinter accounting for 75%. With the depletion of high-quality iron ore resources over the years, high-grade, low-impurity, and fine-particle iron concentrate, obtained through fine grinding and sorting of lean ore, has gradually become a sintering raw material. For example, many steel companies in northern my country primarily rely on domestically produced concentrate. Low iron concentrate content can act as an adhering fines during pelletizing, improving pelletizing performance. However, when the iron concentrate content is too high, the balance between nuclei and adsorbed fines is disrupted, resulting in a thick adhering layer that reduces the permeability of the mixture. To enhance the pelletizing performance and improve the permeability of the material bed with high iron concentrate content, domestic and international researchers have proposed various enhancement measures, such as intensive mixing, the addition of binders, fuel splitting, split-flow pelletizing, and pre-briquetting. Compared to drum mixers, high-power mixers can improve the mixing of iron ore concentrate and binder. Using composite binders to enhance granulation significantly improves the permeability of the mixture and increases sintering yield by approximately 5%. However, composite binders are expensive and difficult to re-mix, which impacts performance. Other researchers have used split-flow granulation and composite agglomeration techniques to enhance the sintering of high-proportion specularite concentrate, achieving promising results. However, this increases the sintering process complexity. Fine-grained iron ore concentrate has a larger specific surface area, capillary water content, and molecularly bound water. Therefore, as its proportion increases, the optimal moisture content of the mixture for granulation increases. During sintering, the excess moisture zone formed by condensation thickens, increasing downward gas resistance and reducing permeability during sintering. This reduces the sintering efficiency and consequently affects the mechanical strength and metallurgical properties of the finished sintered ore. Therefore, it is imperative to develop effective technologies to improve the sintering of high-proportion iron ore concentrate and enhance sintering yield and quality, providing strong technical support for my country's sinter-blast furnace-converter steelmaking process.

[0003] In conventional high-proportion iron ore concentrate sintering technology, in order to ensure the granulation performance of the mixture and the air permeability of the material layer, the moisture content is usually high, which will directly lead to a large amount of water evaporation and heat absorption during the sintering process, resulting in increased energy consumption, lower material layer temperature, and poor consolidation performance; at the same time, high-moisture sintering will also cause serious over-wetting of the material layer, reduced air permeability during the sintering process, decreased oxidation, and inhibited the formation of calcium ferrite solidification phase, resulting in serious impact on sintering production and quality. Summary of the Invention

[0004] In view of the problems in the prior art of "low sintering utilization coefficient, high energy consumption and poor strength of high-proportion iron ore concentrate", the purpose of the present invention is to provide a sintering system and method for pre-drying and strengthening high-proportion iron ore concentrate. After the granulation mixture is distributed and before sintering and ignition, the high-moisture granulation mixture is pre-dried using the sintering high-temperature exhaust gas. On the one hand, the material layer temperature can be increased, and on the other hand, part of the moisture can be removed, thereby reducing the subsequent sintering process of water evaporation and heat absorption and the formation of an over-wet zone at the bottom of the material layer, thereby improving the air permeability of the sintering process, strengthening the sintering liquid phase consolidation, and improving the sintering quality.

[0005] To achieve the above-mentioned object, the present invention provides a sintering system for pre-drying and strengthening high-proportion iron ore concentrate, comprising a sintering machine, the sintering machine being driven by transmission mechanisms provided at the head and tail of the machine, a material distributor being provided at the input end of the sintering machine, and an output end of the material distributor being connected to the input end of the sintering machine;

[0006] The output end of the sintering machine is provided with a crushing mechanism and a screening mechanism, the input end of the crushing mechanism is connected to the output end of the material distributor, and the input end of the screening mechanism is connected to the output end of the crushing mechanism;

[0007] A drying unit is provided between the material distributor and the ignition unit of the sintering machine, and the sintering high-temperature exhaust gas is used to pre-dry the high-moisture granulation mixture.

[0008] Preferably, the drying unit includes a hot air hood provided above the sintering machine, and a high-temperature waste gas recovery unit provided below the sintering machine;

[0009] The high-temperature exhaust gas recovery unit includes several first bellows, the output end of the first bellows is connected to the first flue, the output end of the first flue is provided with a first dust removal device and a first fan, the output end of the first flue is connected to the input end of the first dust removal device, the output end of the first dust removal device is connected to the input end of the first fan, and the output end of the first fan is connected to the hot air hood.

[0010] Preferably, the drying unit also includes a low-temperature exhaust gas exhaust unit, which includes a second wind box arranged below the sintering machine. The number of second wind boxes is several, and the output end of the second wind box is connected to the second flue. The output end of the second flue is provided with a second dust removal device and a second fan. The output end of the second flue is connected to the input end of the second dust removal device, the output end of the second dust removal device is connected to the input end of the second fan, and the output end of the second fan is connected to the chimney.

[0011] Preferably, the crushing mechanism is located above the screening mechanism, so as to facilitate the sequential crushing and screening of the hot sintered ore.

[0012] The present invention also provides a sintering method for pre-drying and strengthening high-proportion iron ore concentrate, comprising the following steps:

[0013] (1) Iron ore concentrate, other iron-containing raw materials, flux, fuel, and return ore are batched, and during the batching process, the sintering basicity is controlled to be 1.6 to 2.2, and the MgO content exceeds 1.4 wt.%;

[0014] (2) fully mixing to obtain a mixture, and then granulating to obtain a granulated mixture;

[0015] (3) Spread the granulated mixture into the sintering machine with a layer height of 600-1100 mm;

[0016] (4) Use sintering high-temperature exhaust gas to dry the material layer; the drying temperature is 250-550°C, the drying time is 60s-180s, and the drying negative pressure is 6kPa-12kPa;

[0017] (5) igniting and sintering in a sintering machine;

[0018] (6) After sintering is completed, the sintered ore is crushed and cooled in a cooler, and then sieved to obtain a finished sintered ore with a particle size of 5 to 40 mm.

[0019] Furthermore, in step (1), the iron ore concentrate includes magnetite concentrate and hematite concentrate; the other iron-containing raw materials include one or more of magnetite, hematite, limonite, sulfuric acid slag, and steel mill dust; the flux is at least one of limestone, dolomite, and quicklime; the fuel is at least one of coke powder, anthracite, and lignite; and the returned ore is -5mm sintered ore produced during the sintering process.

[0020] Furthermore, in step (2), the mixing time is 1 to 3 minutes, the mixer is a drum mixer or a powerful mixer; and the amount of water added during the mixing process is 70 to 90% of the total amount of water added.

[0021] Furthermore, in step (2), granulation is performed by spraying mist water in a cylindrical granulator, the granulation time is 1 to 2 minutes, the amount of water added during the granulation process is 10 to 30% of the total amount of water added, and the particle size of the granulated balls is greater than 1 mm.

[0022] Furthermore, in step (5), the ignition temperature of the ignition process is 1050-1150° C., the ignition time is 1.5 min-2.5 min, and the ignition negative pressure is 5 kPa-7 kPa; and the sintering negative pressure of the sintering process is 10-14 kPa.

[0023] The present invention develops a sintering system and method for pre-drying and strengthening high-proportion iron ore concentrate to effectively improve the sintering characteristics of high-proportion iron ore concentrate, reduce over-wetting, improve the air permeability of the sintering process, reduce its solid fuel consumption, and improve the sintering utilization coefficient.

[0024] Compared with the existing technology, the present invention has the following beneficial effects:

[0025] (1) In order to solve the problems of high moisture content, serious over-humidity and low air permeability in the sintering process of high-proportion iron ore concentrate, which lead to poor sintering product quality, the high-moisture granulation mixture is pre-dried by using the sintering high-temperature exhaust gas after the granulation mixture is distributed and before the sintering ignition. On the one hand, it can increase the temperature of the material layer, and on the other hand, it can remove part of the moisture, reduce the subsequent sintering process of water evaporation and heat absorption, and reduce the formation of an over-humidified zone at the bottom of the material layer, thereby improving the air permeability of the sintering process, strengthening the sintering liquid phase consolidation, and improving the sintering product quality.

[0026] (2) The present invention is easy to implement in actual sintering production, has simple and convenient operation, low pre-drying cost, and can significantly improve the quality of sintered minerals without adding additional energy and excessive investment costs, and has great promotion value; the drying unit is seamlessly connected with the existing sintering machine, and no shutdown modification is required, making it suitable for upgrading old plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings and appendices required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 Schematic diagram of a sintering system for pre-drying and strengthening high-proportion iron ore concentrate in Example 1;

[0029] Figure 2 Schematic diagram of a sintering system for pre-drying and strengthening high-proportion iron ore concentrate in Example 2;

[0030] Figure 3 The permeability change curves of the sintering process of the two technologies;

[0031] Figure 4 The temperature change curves of hot exhaust gas during the sintering process of the two technologies are shown.

[0032] In the figure, 1-sintering machine; 2-transmission mechanism; 3-feeding machine; 4-crushing mechanism; 5-screening mechanism; 6-ignition unit; 7-drying unit; 701-hot air hood; 702-first wind box; 703-first flue; 704-first dust removal device; 705-first fan; 801-second wind box; 802-second flue; 803-second dust removal device; 804-second fan. DETAILED DESCRIPTION

[0033] The following are specific implementation cases provided by the inventors. It should be noted that these embodiments are only for better explanation of the present invention and are not intended to limit the scope of implementation of the present invention. All parameter selections within the scope of the technical solution of the present invention are within the scope of protection of the present invention.

[0034] The following is further described with reference to specific embodiments and accompanying drawings.

[0035] Example 1

[0036] like Figure 1 As shown, a sintering system for pre-drying and strengthening high-proportion iron ore concentrate includes a sintering machine 1. The sintering machine 1 is driven by a transmission mechanism 2 provided at the head and tail of the machine. A material distributor 3 is provided at the input end of the sintering machine 1, and the output end of the material distributor 3 is connected to the input end of the sintering machine 1.

[0037] The output end of the sintering machine 1 is provided with a crushing mechanism 4 and a screening mechanism 5. The input end of the crushing mechanism 4 is connected to the output end of the material distributor 3, and the input end of the screening mechanism 5 is connected to the output end of the crushing mechanism 4.

[0038] A drying unit 7 is provided between the material distributor 3 and the ignition unit 6 of the sintering machine 1 to pre-dry the high-moisture granulation mixture using the high-temperature sintering exhaust gas.

[0039] In this embodiment, the drying unit 7 includes a hot air hood 701 provided above the sintering machine 1 and a high-temperature waste gas recovery unit provided below the sintering machine 1;

[0040] The high-temperature exhaust gas recovery unit includes several first wind boxes 702, the output end of the first wind box 702 is connected to the first flue 703, the output end of the first flue 703 is provided with a first dust removal device 704 and a first fan 705, the output end of the first flue 703 is connected to the input end of the first dust removal device 704, the output end of the first dust removal device 704 is connected to the input end of the first fan 705, and the output end of the first fan 705 is connected to the hot air hood 701.

[0041] In this embodiment, the crushing mechanism 4 is located above the screening mechanism 5, which is convenient for sequentially crushing and screening the hot sintered ore.

[0042] By setting a drying unit between the material distribution machine and the ignition unit of the sintering machine, the high-temperature exhaust gas from sintering is used to pre-dry the high-moisture granulated mixture. On the one hand, the temperature of the material layer can be increased, and on the other hand, part of the moisture can be removed, reducing the heat absorption of water evaporation in the subsequent sintering process and the formation of an over-wet zone at the bottom of the material layer, thereby improving the air permeability of the sintering process, strengthening the consolidation of the sintering liquid phase, and improving the sintering quality.

[0043] Example 2

[0044] This embodiment is a further improvement on embodiment 1, with the only difference being:

[0045] The drying unit 7 also includes a low-temperature exhaust gas exhaust unit, which includes a second wind box 801 provided below the sintering machine 1. The number of second wind boxes 801 is several. The output end of the second wind box 801 is connected to the second flue 802. The output end of the second flue 802 is provided with a second dust removal device 803 and a second fan 804. The output end of the second flue 802 is connected to the input end of the second dust removal device 803. The output end of the second dust removal device 803 is connected to the input end of the second fan 804. The output end of the second fan 804 is connected to the chimney 805. Figure 2 shown.

[0046] Example 3

[0047] A sintering method for pre-drying and strengthening high-proportion iron ore concentrate comprises the following steps:

[0048] (1) 50% iron ore concentrate, 10% other iron ore powder, 25 wt% return ore powder, 3.4% coke powder, 4.0% quicklime, limestone and dolomite were mixed to obtain a mixture with a basicity of about 1.85 and a MgO content of 1.45%;

[0049] (2) Add an appropriate amount of water to the mixture in step (1) to adjust the moisture content of the mixture to 7.5%. Mix in a drum mixer with a filling rate of 15% and a mixing time of 3 minutes; then granulate in a drum granulator. The sintered material has a particle size greater than 0.5 mm, accounting for 98% by weight, and a particle size greater than 1 mm, accounting for 80% by weight.

[0050] (3) The sintering material of step (2) is loaded into the sintering machine, and the height of the sintering material layer is 800 mm;

[0051] (4) Sintering waste gas is used for drying, the drying temperature is 250°C, the drying time is 60s, and the drying negative pressure is 7kPa;

[0052] (5) controlling the ignition negative pressure to 6 kPa, the ignition temperature to (1100 ± 50) °C, and the ignition time to 1.5 min, and igniting the sintering material; sintering is performed at a sintering negative pressure of 11 kPa to obtain hot sintered ore;

[0053] (6) The hot sintered ore is cooled by blasting, with a cooling negative pressure of 5 kPa and a cooling time of 5 min to obtain cold sintered ore with a temperature below 100°C; the cold sintered ore is crushed and sieved to obtain finished sintered ore of 5 to 40 mm and returned ore powder of -5 mm.

[0054] Determine the relevant sintering indicators, including yield, utilization coefficient, drum strength, solid fuel consumption, etc. The sintering process sintering indicators are: drum strength 55.34%, yield from 64.38%, utilization coefficient from 1.38t·m -2 ·h -1 , solid fuel consumption is 54.38kg / t.

[0055] Example 4

[0056] A sintering method for pre-drying and strengthening high-proportion iron ore concentrate comprises the following steps:

[0057] (1) 50% iron ore concentrate, 10% other iron ore powder, 25 wt% return ore powder, 3.4% coke powder, 4.0% quicklime, limestone and dolomite were mixed to obtain a mixture with a basicity of about 1.85 and a MgO content of 1.45%;

[0058] (2) Add an appropriate amount of water to the mixture in step (1) to adjust the moisture content of the mixture to 7.5%. Mix in a drum mixer with a filling rate of 15% and a mixing time of 3 minutes; then granulate in a drum granulator. The sintered material has a particle size greater than 0.5 mm, accounting for 98% by weight, and a particle size greater than 1 mm, accounting for 80% by weight.

[0059] (3) The sintering material of step (2) is loaded into the sintering machine, and the height of the sintering material layer is 800 mm;

[0060] (4) Sintering waste gas is used for drying, the drying temperature is 350°C, the drying time is 80s, and the drying negative pressure is 8kPa;

[0061] (5) controlling the ignition negative pressure to 6 kPa, the ignition temperature to (1100 ± 50) °C, and the ignition time to 1.5 min, and igniting the sintering material; sintering is performed at a sintering negative pressure of 12 kPa to obtain hot sintered ore;

[0062] (6) The hot sintered ore is cooled by blasting, with a cooling negative pressure of 5 kPa and a cooling time of 5 min to obtain cold sintered ore with a temperature below 100°C; the cold sintered ore is crushed and sieved to obtain finished sintered ore of 5 to 40 mm and returned ore powder of -5 mm.

[0063] Determine the relevant sintering indicators, including yield, utilization coefficient, drum strength, solid fuel consumption, etc. The sintering process sintering indicators are: drum strength 55.89%, yield from 64.68%, utilization coefficient from 1.42t·m -2 ·h -1 , solid fuel consumption is 54.16kg / t.

[0064] Example 5

[0065] A sintering method for pre-drying and strengthening high-proportion iron ore concentrate comprises the following steps:

[0066] (1) 55% iron ore concentrate, 5% other iron ore powder, 25 wt% return ore powder, 3.4% coke powder, 4.0% quicklime, limestone and dolomite were mixed to obtain a mixture with a basicity of about 1.85 and a MgO content of 1.45%;

[0067] (2) Add an appropriate amount of water to the mixture in step (1) to adjust the moisture content of the mixture to 7.5%. Mix in a drum mixer with a filling rate of 15% and a mixing time of 2 minutes; then granulate in a drum granulator. The sintered material has a particle size greater than 0.5 mm, accounting for 95% by weight, and a particle size greater than 1 mm, accounting for 78% by weight.

[0068] (3) The sintering material of step (2) is loaded into the sintering machine, and the height of the sintering material layer is 800 mm;

[0069] (4) Sintering waste gas is used for drying, the drying temperature is 400°C, the drying time is 90s, and the drying negative pressure is 10kPa;

[0070] (5) controlling the ignition negative pressure to 6 kPa, the ignition temperature to (1100 ± 50) °C, and the ignition time to 1.5 min, and igniting the sintering material; sintering is performed at a sintering negative pressure of 12 kPa to obtain hot sintered ore;

[0071] (6) The hot sintered ore is cooled by blasting, with a cooling negative pressure of 5 kPa and a cooling time of 5 min to obtain cold sintered ore with a temperature below 100°C; the cold sintered ore is crushed and sieved to obtain finished sintered ore of 5 to 40 mm and returned ore powder of -5 mm.

[0072] Determine the relevant sintering indicators, including yield, utilization coefficient, drum strength, solid fuel consumption, etc. The sintering process sintering indicators are: drum strength 56.34%, yield from 64.92%, utilization coefficient from 1.47t·m -2 ·h -1 , solid fuel consumption is 54.06kg / t.

[0073] Example 6

[0074] A sintering method for pre-drying and strengthening high-proportion iron ore concentrate comprises the following steps:

[0075] (1) 55% iron ore concentrate, 5% other iron ore powder, 25 wt% return ore powder, 3.4% coke powder, 4.0% quicklime, limestone and dolomite were mixed to obtain a mixture with a basicity of about 1.85 and a MgO content of 1.45%;

[0076] (2) Add an appropriate amount of water to the mixture in step (1) to adjust the moisture content of the mixture to 7.5%. Mix in a drum mixer with a filling rate of 15% and a mixing time of 2 minutes; then granulate in a drum granulator. The sintered material has a particle size greater than 0.5 mm, accounting for 95% by weight, and a particle size greater than 1 mm, accounting for 78% by weight.

[0077] (3) The sintering material of step (2) is loaded into the sintering machine, and the height of the sintering material layer is 800 mm;

[0078] (4) Sintering waste gas is used for drying, the drying temperature is 450°C, the drying time is 110s, and the drying negative pressure is 9kPa;

[0079] (5) controlling the ignition negative pressure to 6 kPa, the ignition temperature to (1100 ± 50) °C, and the ignition time to 1.5 min, and igniting the sintering material; sintering is performed at a sintering negative pressure of 12 kPa to obtain hot sintered ore;

[0080] (6) The hot sintered ore is cooled by blasting, with a cooling negative pressure of 5 kPa and a cooling time of 5 min to obtain cold sintered ore with a temperature below 100°C; the cold sintered ore is crushed and sieved to obtain finished sintered ore of 5 to 40 mm and returned ore powder of -5 mm.

[0081] Determine the relevant sintering indicators, including yield, utilization coefficient, drum strength, solid fuel consumption, etc. The sintering process sintering indicators are: drum strength 56.95%, yield from 65.01%, utilization coefficient from 1.53t·m -2 ·h -1 , solid fuel consumption is 52.86kg / t.

[0082] Comparative Example 1

[0083] (1) 50% iron ore concentrate, 10% other iron ore powder, 30% return ore powder, 3.4% coke powder, 4.0% quicklime, limestone and dolomite were mixed to obtain a mixture with a basicity of about 1.85 and a MgO content of 1.45%;

[0084] (2) Add an appropriate amount of water to the mixture in step (1) to adjust the moisture content of the mixture to 7.5%. Mix in a drum mixer with a filling rate of 15% and a mixing time of 3 minutes; then granulate in a drum granulator. The sintered material has a particle size greater than 0.5 mm, accounting for 98% by weight, and a particle size greater than 1 mm, accounting for 80% by weight.

[0085] (3) The sintered material from step (2) was loaded into a sintering machine with a sintering layer height of 800 mm; the ignition negative pressure was controlled to be 6 kPa, the ignition temperature to be (1100 ± 50) °C, and the ignition time to be 1.5 min, and the sintered material was ignited;

[0086] (4) sintering under a sintering negative pressure of 11 kPa to obtain hot sintered ore;

[0087] (5) Cooling the hot sintered ore by blasting, with a cooling negative pressure of 5 kPa and a cooling time of 5 min to obtain cold sintered ore with a temperature below 100°C;

[0088] (6) The cold sintered ore is crushed and screened to obtain 5-40 mm finished sintered ore and -5 mm returned ore powder.

[0089] Determine the relevant sintering indicators, including yield, utilization coefficient, drum strength, solid fuel consumption, etc. The sintering process sintering indicators are: drum strength 54.21%, yield from 64.22%, utilization coefficient from 1.32t·m -2 ·h -1 , solid fuel consumption is 54.68kg / t.

[0090] The present invention conducts sintering cup tests on ordinary sintering process and pellet sintering process to compare and illustrate the feasibility of pre-drying to enhance the sintering of high-proportion iron ore concentrate, and provides a new method for sintering high-proportion iron ore concentrate that can effectively improve the sintering performance.

[0091] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be considered as equivalent replacement methods and are included in the scope of protection of the present invention.

Claims

1. A sintering system for pre-drying and strengthening high-proportion iron ore concentrate, characterized in that: The invention comprises a sintering machine (1), wherein the sintering machine (1) is driven by a transmission mechanism (2) provided at the head and tail of the machine, and a material distributor (3) is provided at the input end of the sintering machine (1), and the output end of the material distributor (3) is connected to the input end of the sintering machine (1); The output end of the sintering machine (1) is provided with a crushing mechanism (4) and a screening mechanism (5); the input end of the crushing mechanism (4) is connected to the output end of the material distributor (3); and the input end of the screening mechanism (5) is connected to the output end of the crushing mechanism (4); A drying unit (7) is provided between the material distributor (3) and the ignition unit (6) of the sintering machine (1), and the high-temperature sintering waste gas is used to pre-dry the high-moisture granulation mixture.

2. The sintering system for pre-drying and strengthening high-proportion iron ore concentrate according to claim 1, characterized in that: The drying unit (7) comprises a hot air hood (701) arranged above the sintering machine (1), and a high-temperature waste gas recovery unit arranged below the sintering machine (1); The high-temperature waste gas recovery unit comprises a plurality of first wind boxes (702), the output end of the first wind box (702) is connected to the first flue (703), the output end of the first flue (703) is provided with a first dust removal device (704) and a first fan (705), the output end of the first flue (703) is connected to the input end of the first dust removal device (704), the output end of the first dust removal device (704) is connected to the input end of the first fan (705), and the output end of the first fan (705) is connected to the hot air hood (701).

3. The sintering system for pre-drying and strengthening high-proportion iron ore concentrate according to claim 1, characterized in that: The drying unit (7) further includes a low-temperature waste gas exhaust unit, which includes a second wind box (801) arranged below the sintering machine (1). The number of second wind boxes (801) is several, the output end of the second wind box (801) is connected to the second flue (802), the output end of the second flue (802) is provided with a second dust removal device (803) and a second fan (804), the output end of the second flue (802) is connected to the input end of the second dust removal device (803), the output end of the second dust removal device (803) is connected to the input end of the second fan (804), and the output end of the second fan (804) is connected to the chimney (805).

4. The sintering system for pre-drying and strengthening high-proportion iron ore concentrate according to claim 1, characterized in that: The crushing mechanism (4) is located above the screening mechanism (5).

5. A sintering method for pre-drying and strengthening high-proportion iron ore concentrate, characterized in that: The following steps are involved: (1) Iron ore concentrate, other iron-containing raw materials, flux, fuel, and return ore are batched, and during the batching process, the sintering basicity is controlled to be 1.6 to 2.2, and the MgO content exceeds 1.4 wt.%; (2) fully mixing to obtain a mixture, and then granulating to obtain a granulated mixture; (3) Spread the granulated mixture into the sintering machine with a layer height of 600-1100 mm; (4) Use sintering high-temperature exhaust gas to dry the material layer; the drying temperature is 250-550°C, the drying time is 60s-180s, and the drying negative pressure is 6kPa-12kPa; (5) igniting and sintering in a sintering machine; (6) After sintering is completed, the sintered ore is crushed and cooled in a cooler, and then sieved to obtain a finished sintered ore with a particle size of 5 to 40 mm.

6. The sintering method of pre-dried and strengthened high-proportion iron ore concentrate according to claim 5, characterized in that: In step (1), the iron ore concentrate includes magnetite concentrate and hematite concentrate; the other iron-containing raw materials include one or more of magnetite, hematite, limonite, sulfuric acid slag, and steel mill dust; the flux is at least one of limestone, dolomite, and quicklime; the fuel is at least one of coke powder, anthracite, and lignite; and the returned ore is -5mm sintered ore produced during the sintering process.

7. The sintering method of pre-dried and strengthened high-proportion iron ore concentrate according to claim 5, characterized in that: In step (2), the mixing time is 1 to 3 minutes, and the mixer is a drum mixer or a powerful mixer; the amount of water added during the mixing process is 70 to 90% of the total amount of water added.

8. The sintering method of pre-dried and strengthened high-proportion iron ore concentrate according to claim 5, characterized in that: In step (2), spraying mist water in a cylindrical granulator is used for granulation, the granulation time is 1 to 2 minutes, the amount of water added during the granulation process is 10 to 30% of the total amount of water added, and the particle size of the granulated balls is greater than 1 mm.

9. The sintering method of pre-dried and strengthened high-proportion iron ore concentrate according to claim 5, characterized in that: In step (5), the ignition temperature during the ignition process is 1050-1150° C., the ignition time is 1.5 min-2.5 min, and the ignition negative pressure is 5 kPa-7 kPa; and the sintering negative pressure during the sintering process is 10-14 kPa.

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