A method for producing a manganese-containing pellet and a method for blast furnace smelting

Abstract

The application relates to a preparation method of a manganese-containing pellet and a blast furnace smelting method, which comprises the following steps: step a, crushing, water-fine grinding and drying treatment are carried out on high-manganese lump ore to obtain high-manganese concentrate; step b, the high-manganese concentrate and bentonite are uniformly mixed according to a preset ratio to obtain a mixture; step c, the mixture is added into a disc pelletizer, and a pellet core is obtained in a water dripping ball forming mode; step d, based on the pellet core, the water content ratio and the balling time added into the disc pelletizer are controlled, so that the residual mixture of the mixture is uniformly wrapped on the outer layer of the pellet core, and a manganese-containing pellet is obtained. The method improves the traditional preparation method of the manganese-containing pellet, improves the quality of the manganese-containing pellet, and obtains the manganese-containing pellet meeting the performance standard of the blast furnace smelting. The blast furnace adding mode is optimized, the utilization efficiency of the manganese ore is improved, the iron loss is reduced, and the smelting of the high-titanium slag is improved.

Description

Technical Field

[0001] This invention relates to the field of iron and steel metallurgy, specifically to a method for preparing manganese-containing pellets and a method for blast furnace smelting. Background Technology

[0002] For smelting high-titanium vanadium-titanium magnetite, the high titanium dioxide (TiO2) content in the slag (generally above 20%) makes it easy for TiO2 in the slag to undergo over-reduction reaction, generating low-valence titanium carbonitride (Ti(C,N)). The increase in low-valence Ti(C,N) will raise the slag melting temperature and slag viscosity, making it difficult to separate slag from iron, increasing the amount of iron carried in the slag, and increasing blast furnace iron loss. In severe cases, it may even affect the blast furnace smelting of vanadium-titanium magnetite.

[0003] To address these issues, a common practice is to add a certain proportion of iron-manganese ore lumps to the top of the blast furnace along with the initial charge. This proportion is typically around 1% of the initial charge. The reduction of manganese oxide (MnO) in the iron-manganese ore at high temperatures is utilized to increase the oxygen potential of the slag, reducing the formation of high-melting-point Ti (C, N) in the vanadium-titanium blast furnace slag and thus improving slag performance. While this method of directly adding iron-manganese ore lumps to the blast furnace with the initial charge can improve the performance of high-titanium slag, the uneven particle size (ranging from 3 mm to over 20 mm) and highly uneven chemical composition between large and small particles, coupled with the fact that the lumps are raw material with poor metallurgical properties (a wide softening range at high temperatures), easily cause fluctuations in blast furnace conditions. This prevents the full utilization of the iron-manganese ore's properties and leads to a waste of iron-manganese ore resources.

[0004] In existing technologies, magnetite is generally used as the main raw material, and the magnetite is used to form pellets through magnetic aggregation and moisture adsorption; or magnetite is used as the main material, and some hematite, iron oxide and other materials are added to form pellets to obtain high manganese pellets. However, pelletizing is difficult and it is not easy to prepare manganese-containing pellets with the required performance. Therefore, it is difficult to meet the demand for manganese-containing pellets in actual production processes.

[0005] Therefore, existing technologies still need improvement. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a method for preparing manganese-containing pellets that meet blast furnace smelting performance standards using high-manganese lump ore as raw material, and for blast furnace smelting based on high-manganese-containing pellets, thereby improving slag viscosity, reducing iron loss, and enhancing blast furnace smelting.

[0007] Specifically, the present invention provides a method for preparing manganese-containing pellets, comprising: step a, crushing, finely grinding with water, and drying high-manganese lumps to obtain high-manganese concentrate; step b, uniformly mixing the high-manganese concentrate and bentonite according to a preset ratio to obtain a mixture; step c, adding the mixture to a disc pelletizer and obtaining pellet cores in a drip-forming mode; and step d, controlling the water ratio and pelletizing time added to the disc pelletizer based on the pellet cores to ensure that the remaining mixture is uniformly coated on the outer layer of the pellet cores to obtain manganese-containing pellets.

[0008] In an embodiment of the present invention, step d includes: step d1, adding 8% to 10% moisture to the disc pelletizer based on the pellet core control and a pelletizing time of 15 to 30 minutes, so that the remaining mixture of the mixture is uniformly coated on the outer layer of the pellet core to obtain green pellets; step d2, performing particle size screening on the green pellets to obtain high manganese concentrate green pellets with a particle size of 8 to 16 mm; step d3, drying, roasting and cooling the high manganese concentrate green pellets to obtain manganese-containing pellet ore.

[0009] In an embodiment of the present invention, step d3 includes: drying the green pellets of high manganese concentrate at a temperature of 150-300°C for 2-3 hours; after drying, preheating them in a muffle furnace at a temperature of 800-1000°C for 15-25 minutes; after preheating, roasting them by introducing air at a temperature of 1150-1300°C for 20-30 minutes; and after roasting, cooling them by introducing air into the muffle furnace to obtain manganese-containing pellets.

[0010] In an embodiment of the present invention, step a includes: step a1, crushing and finely grinding the high-manganese lump ore with water to obtain a slurry; step a2, allowing the slurry to stand and removing the clear liquid from its surface; step a3, drying, grinding and sieving the slurry after removing the clear liquid to obtain a high-manganese concentrate.

[0011] In an embodiment of the present invention, step a1 includes: crushing the high-manganese lump ore to less than 1 mm, adding water to make the high-manganese ore concentration 60-65%, and finely grinding for 8-10 minutes to obtain a slurry with a particle size of less than 0.074 mm accounting for 60-70%.

[0012] In an embodiment of the present invention, step a2 includes: placing the slurry in a slurry tank and letting it stand for 3 to 5 minutes, then removing the clear liquid from the surface of the slurry.

[0013] In an embodiment of the present invention, step a3 includes: drying the slurry after removing the supernatant at a temperature of 150°C for 40 to 50 hours, then grinding it and sieving it with a 100-mesh screen to obtain high-manganese concentrate.

[0014] In an embodiment of the present invention, step b includes: uniformly mixing high manganese concentrate and bentonite in a ratio of (95-99%): (1-5%) for 10 minutes to obtain a mixture.

[0015] In another aspect, the present invention provides a method for blast furnace smelting, including the preparation method of any of the manganese-containing pellets described above.

[0016] In an embodiment of the present invention, the method further includes: controlling the proportion of manganese-containing pellets transferred to the feeding belt, so that the manganese-containing pellets are uniformly mixed with the iron-containing pellets and / or sinter on the feeding belt and then fed into the blast furnace for smelting.

[0017] In embodiments of the present invention, the proportion includes a weight percentage of 1 to 3%.

[0018] The beneficial effects of this invention are as follows: This invention provides a method for preparing manganese-containing pellets and a method for blast furnace smelting. Using high-manganese lump ore as raw material, it is crushed, finely ground, and then roasted to produce manganese-containing pellets. In this method, high-manganese concentrate with a particle size of less than 0.074 mm accounting for more than 60% after fine grinding is mixed with bentonite for pelletizing. The addition of moisture and the pelletizing time are controlled during the pelletizing process, which improves the traditional method for preparing manganese-containing pellets, improves the quality of manganese-containing pellets, and obtains manganese-containing pellets that meet the performance standards for blast furnace smelting. Furthermore, the prepared manganese-containing pellets were mixed with iron-containing pellets and iron-containing sinter to ensure that the manganese-containing pellets were evenly distributed among the iron-containing pellets and sinter. Then, they were added to the blast furnace for smelting. This effectively improved the physical and chemical properties and metallurgical properties of the high-manganese lump ore, optimized the blast furnace addition method, improved the utilization efficiency of manganese ore, and also improved the problem of poor metallurgical performance caused by uneven particle size and composition fluctuation of high-manganese lump ore. It also reduced iron loss and improved the smelting of high-titanium slag. Attached Figure Description

[0019] Figure 1 A flowchart of a method for preparing manganese-containing pellets according to an embodiment of the present invention is shown;

[0020] Figure 2 The diagram shown is a schematic representation of a blast furnace smelting method provided in an embodiment of the present invention. Detailed Implementation

[0021] It should be understood that the embodiments of the invention shown in the exemplary embodiments are merely illustrative. Although only a few embodiments have been described in detail in this invention, those skilled in the art will readily recognize that various modifications are possible without substantially departing from the teachings of the invention. Accordingly, all such modifications should be included within the scope of the invention. Other substitutions, modifications, variations, and deletions can be made to the design, operating conditions, and parameters of the following exemplary embodiments without departing from the spirit of the invention.

[0022] According to the present invention, a method for preparing manganese-containing pellets is provided, such as... Figure 1 As shown, it includes:

[0023] Step a: Crush, grind with water, and dry the high-manganese lump ore to obtain high-manganese concentrate;

[0024] Step b: Mix the high-manganese concentrate and bentonite evenly according to a preset ratio to obtain a mixture;

[0025] Step c: Add the mixture to the disc pelletizer and obtain the pellet core in the drip pelletizing mode;

[0026] Step d: Based on the control of the core of the pellet, the moisture ratio and pelletizing time of the disc pelletizer are added to make the remaining mixture of the mixture uniformly coat the outer layer of the core of the pellet to obtain manganese-containing pellets.

[0027] In an embodiment of the present invention, in step a, the iron-manganese lump ore can be crushed to below 1 mm using a jaw crusher, and then finely ground to below 0.074 mm using a ball mill at a grinding concentration of 60-65% and a grinding time of 8-10 minutes, achieving a particle size ratio of 60-70%, to obtain a slurry. The slurry is placed in a slurry tank for settling treatment for 3-5 minutes, and then the clear liquid on the surface of the settling slurry is removed. The slurry after removing the clear liquid is then dried in an oven at 150°C for 40-50 hours. After drying, it is milled and sieved through a 100-mesh screen to obtain a high-manganese concentrate. The high-manganese lump ore contains more than 50% manganese oxide (MnO), and the high-manganese concentrate contains more than 60% particles smaller than 0.074 mm, basically meeting the raw material particle size requirements for pellet production.

[0028] In an embodiment of the present invention, in step b, high manganese concentrate and bentonite are mixed uniformly in a V-type mixer at a ratio of (95-99%):(1-5%) for 10 minutes to obtain a mixture. Preferably, the high manganese concentrate and bentonite are uniformly mixed at a ratio of (97-98%):(2-3%). The bentonite used has a particle size of less than 0.074 mm, accounting for approximately 98%.

[0029] In an embodiment of the present invention, in step c, the above mixture is placed in a disc pelletizing machine, and pellet cores of 1 to 2 mm are formed by dripping water to form pellets, i.e., mother balls. The disc pelletizing machine is Φ1000×350mm, with a rotation speed of 20 to 25 r / min and an adjustable tilt angle of 40 to 50°.

[0030] In an embodiment of the present invention, in step d, the remaining mixture is continuously added to the disc pelletizer, and water (atomized water) is continuously added to control the moisture content of the finished green pellets to 8.0%–10%, preferably 8.5%–9.0%, so that the remaining mixture is evenly coated on the outer layer of the pellet core. The pelletizing time is controlled to be 15–30 minutes, preferably 20–25 minutes, to obtain green pellets, which are then subjected to particle size screening to obtain green pellets with a particle size of 8–16 mm. The green pellets are then subjected to particle size screening to obtain green pellets that meet the performance requirements, with a particle size of 8–16 mm, a lower strength greater than 5 times / 0.5 m, and a compressive strength greater than 10 N / pellet. The green pellets are then dried, roasted, and cooled to obtain manganese-containing pellet ore. The obtained manganese-containing pellet ore has a particle size of 6–14 mm (high manganese concentrate has a higher loss on ignition value, and the volume shrinkage after roasting is 2–4 mm), and a compressive strength greater than 1500 N / pellet.

[0031] The drying temperature for the green pellets is 150–300℃, preferably 200–250℃, and the drying time is 2–3 hours. The dried green pellets are then placed in a muffle furnace (with an added air pump) for preheating and roasting. The preheating temperature is 800–1000℃, and the preheating time is 15–25 minutes. The roasting temperature is 1150–1300℃, and the roasting time is 20–30 minutes. Preferably, the preheating temperature is 900–950℃, and the preheating time is 20 minutes. The roasting temperature is 1200–1250℃, and the roasting time is 25 minutes. After roasting, the heating coupler of the muffle furnace is turned off, and air is continued to be introduced for cooling. The heating rate and temperature of the muffle furnace can be set, with the temperature not exceeding 1400℃ and the heating rate adjustable from 5 to 10℃ / minute. Air can also be introduced into the muffle furnace via an air pump as needed, with the air flow rate adjustable from 0.5 to 3L / minute.

[0032] Another aspect of the embodiments of the present invention provides a method for blast furnace smelting, including any step of the above-described method for preparing manganese-containing pellets, and further including controlling the proportion of manganese-containing pellets transferred to the feeding belt, so that the manganese-containing pellets are uniformly mixed with iron-containing pellets and / or sinter on the feeding belt before being fed into the blast furnace for smelting. Figure 2 As shown, Figure 2The diagram shown is a schematic diagram of a blast furnace smelting method provided by an embodiment of the present invention, including: (1) crushing and grinding: using a jaw crusher to crush iron-manganese ore to less than 1 mm, and then using a ball mill to grind iron-manganese ore to less than 0.074 mm with a grinding concentration of 60-65% and a grinding time of 8-10 min to obtain slurry. The slurry is placed in a slurry pool for static treatment for 3-5 min. Then, the clear liquid on the surface of the static slurry is stripped off. The stripped slurry is dried at an oven temperature of 150°C for 40-50 h. The dried slab sample is ground and sieved through a 100-mesh screen. The undersize material (high manganese concentrate) is reserved for use.

[0033] (2) Ingredients: Weigh 95-99% high manganese concentrate and 1-5% bentonite by weight percentage. Preferably, the proportion of high manganese concentrate is 97-98% and the proportion of bentonite is 2-3%.

[0034] (3) Mixing: Place the weighed materials into a V-type mixer for mixing and uniform mixing for 10 minutes.

[0035] (4) Primary pelletizing: The above mixture is placed in a disc pelletizing machine and pelletized into a 1-2 mm pellet core, i.e., mother pellet, by dripping water to form pellets.

[0036] (5) Secondary pelletizing: The remaining mixture is continuously added to the disc pelletizer and atomized water is continuously added to control the moisture content of the finished green pellets to 8.0% to 10%, preferably 8.5% to 9.0%; the dry material is evenly coated on the outer layer of the pellet core material, and the pelletizing time is maintained at 15 to 30 minutes, preferably 20 to 25 minutes. The rolled green pellets are screened to ensure that the green pellet particle size reaches 8 to 16 mm, forming high manganese concentrate green pellets;

[0037] (6) Drying: Dry the green balls at a temperature of 150-300℃, preferably 200-250℃, for 2-3 hours;

[0038] (7) Preheating and roasting: The dried green balls are placed in the modified muffle furnace (with an added air pump) for preheating and roasting. The preheating temperature is 800-1000℃ and the preheating time is 15-25 min. The roasting temperature is 1150-1300℃ and the roasting time is 20-30 min. Preferably, the preheating temperature is 900-950℃ and the preheating time is 20 min. The roasting temperature is 1200-1250℃ and the roasting time is 25 min.

[0039] (8) Cooling: After calcination, turn off the heating coupler and continue to introduce air for cooling;

[0040] (9) Charging and feeding: The cooled finished pellets are placed into the storage bin. They are then fed from the storage bin at a weight percentage of 1 to 3% onto the feeding belt of the vanadium-titanium pellets or high-titanium sinter, preferably 2%. Finally, the sinter or pellets containing high-manganese concentrate pellets are fed through the feeding chute at the feeding angle set for blast furnace smelting, so that the high-manganese concentrate pellets are evenly dispersed among the iron-containing materials for blast furnace smelting.

[0041] In some embodiments of the present invention, the high-manganese lump ore used for crushing and grinding has an MnO content of more than 50%, which is a high-quality manganese-containing raw material. After fine grinding, the proportion of high-manganese concentrate with particles smaller than 0.074 mm reaches more than 60%, which basically meets the raw material particle size requirements for pellet production.

[0042] In some embodiments of the present invention, the bentonite particles with a particle size of less than 0.074 mm account for about 98% of the ingredients.

[0043] In some embodiments of the present invention, a disc pelletizer is used for pelletizing, wherein the disc pelletizer is Φ1000×350mm, the rotation speed is 20~25r / min, and the tilt angle is adjustable from 40 to 50°.

[0044] In some embodiments of the present invention, the qualified green pellets obtained by pelletizing have a particle size of 8-16 mm, the green pellet drop strength is controlled to be greater than 5 times / 0.5 m, and the compressive strength is greater than 10 N / pellet.

[0045] In some embodiments of the present invention, both preheating and calcination are performed using an experimental muffle furnace, the heating rate and temperature can be set, the maximum temperature is 1400℃, and the heating rate is adjustable from 5℃ / min to 10℃ / min. At the same time, the muffle furnace can be modified to allow air to be introduced according to experimental requirements, and the air flow rate is adjustable from 0.5 to 3L / min.

[0046] The resulting high-manganese concentrate pellets have a particle size of 6–14 mm (high-manganese concentrate has a high loss on ignition, and its volume shrinks by 2–4 mm after roasting), and a compressive strength greater than 1500 N / pellet.

[0047] The present invention provides a method for preparing manganese-containing pellets and a method for blast furnace smelting, which changes the traditional mode of directly feeding high-manganese lump ore into the furnace for smelting. The high-manganese lump ore is crushed, finely ground, and then calcined into pellets before being added to the blast furnace. This not only improves the performance of high-titanium slag, but also improves the problems of uneven particle size, composition fluctuation and poor metallurgical performance of high-manganese lump ore, thereby improving the effect of blast furnace smelting.

[0048] Most existing pelletizing techniques use magnetite as raw material, relying on the magnetic aggregation of magnetite and moisture adsorption to form pellets, or use magnetite as the main material with the addition of hematite, iron oxide, etc., resulting in pellets of unreliable quality. This invention directly uses high-manganese concentrate with a finely ground particle size of more than 60% by adding bentonite, controlling moisture and pelletizing time during the pelletizing process to obtain high-manganese concentrate pellets that meet performance standards.

[0049] In existing technologies, high-manganese lump ore is added to the blast furnace in batches, taking advantage of the diffusivity and fluidity of the high-temperature molten slag. However, since blast furnace smelting is a continuous production process, it is easy to cause local MnO accumulation and local deficiency. This invention mixes high-manganese concentrate pellets with sinter and pellets to ensure that the MnO in the high-manganese concentrate pellets is evenly distributed around the titanium-containing materials before adding them to the blast furnace for smelting. This can reduce the formation of high-melting-point Ti(C,N) substances, improve slag viscosity, reduce iron loss, and enhance blast furnace smelting.

[0050] The following specific embodiments further illustrate the concept of the present invention. It should be understood that the following embodiments are further illustrative of the present invention and are not intended to limit the scope of the present invention.

[0051] The physicochemical parameters of the high-manganese lump ore and bentonite of this invention are as follows:

[0052] High manganese concentrate: w(MnO) 50.00%–55.00%, w(TFe) 0.00%–5.00%, w(FeO) <0.5%, w(CaO) 6.00%–7.50%, w(SiO2) 8.00%–9.50%, w(Al2O3) 2.50%–4.00%, Ig 15.00%–18.00%;

[0053] Bentonite: w(CaO) 2.00%–5.00%, w(SiO2) 40.00%–60.00%, w(Al2O3) 12.00%–18%, w(MgO) 2.00%–5.00%;

[0054] The particle size distribution of high manganese lump ore and bentonite is shown in Table 1, and the raw material ratio of high manganese concentrate pellets is shown in Table 2.

[0055]

[0056] Table 1

[0057] Example 1 Example 2 Example 3 High manganese concentrate 98 97.5 97 Bentonite 2 2.5 3

[0058] Table 2

[0059] According to Table 2, weigh the two materials according to the corresponding ratio, and after weighing, add them to a high-strength mixer for thorough mixing. The mixing time is 10 minutes to form a mixture.

[0060] A portion of the mixed material is added to a disc pelletizer for primary pelletizing, with the moisture content controlled at 8.5–9%. The disc pelletizer is Φ1000×350mm, with a rotation speed of 20r / min and an inclination angle of 48°. This produces pellet cores with a particle size of 1–2mm. The pellet cores are then subjected to secondary pelletizing, with the remaining mixed material evenly coating the core material. By continuously adding mixed material and atomized water, the high manganese concentrate pellets are grown to form green pellets with a particle size of 8–16mm.

[0061] The green pellets were subjected to drop strength and compressive strength tests. The drop strength test involved raising the green pellets to a height of 0.5 meters and then allowing them to fall freely onto an iron plate. The number of drops and the breakage rate were counted. The compressive strength test involved placing the green pellets directly into a compression testing device. The weight of the produced green pellets was then calculated as the ratio of the weight added to the disc pelletizer, representing the yield of the high-manganese concentrate pellets. Finally, the green pellets were dried in a drying oven at 200°C for 2 hours, then transferred to a muffle furnace for preheating and roasting at 900°C for 20 minutes and 1200°C for 30 minutes. The roasted pellets were then allowed to cool naturally for 6 hours. After complete cooling, the compressive strength and chemical composition were tested.

[0062] The following provides a detailed comparison of various indicators for the raw and finished pellets of Examples 1, 2, and 3.

[0063] Example 1

[0064] The raw materials by weight percentage were: 98% high manganese concentrate and 2% bentonite. The moisture content of the green pellets was controlled at 8.5%. The pellets were formed twice in a disc pelletizer, with the first pelletizing time being 5 minutes and the second pelletizing time being 15 minutes. The compressive strength of the green pellets was tested to be 12.48 N / pellet, the drop strength was 8.0 drops / pellet, the bursting temperature was greater than 600℃, and the green pellet formation rate was 69.78%.

[0065] The finished pellets have a compressive strength of 1520 N / piece, a medium-temperature reducing expansion coefficient of 10.73%, a MnO content of 81.66%, a TFe content of 4.62%, a SiO2 content of 9.03%, a CaO content of 7.37%, an Al2O3 content of 3.40%, and a MgO content of 1.89%.

[0066] Example 2

[0067] The raw materials by weight percentage were: 97.5% high manganese concentrate, 2.5% bentonite, and the moisture content of the green pellets was controlled at 8.5%. The pellets were formed twice in a disc pelletizer, with the first pelletizing time being 5 minutes and the second pelletizing time being 15 minutes. The compressive strength of the green pellets was tested to be 14.78 N / pellet, the drop strength was 8.6 drops / pellet, the bursting temperature was greater than 600℃, and the green pellet formation rate was 72.44%.

[0068] The finished pellets have a compressive strength of 1670 N / piece, a medium-temperature reducing expansion coefficient of 9.79%, a MnO content of 80.54%, a TFe content of 4.33%, a SiO2 content of 9.65%, a CaO content of 7.51%, an Al2O3 content of 3.89%, and a MgO content of 1.92%.

[0069] Example 3

[0070] The raw materials by weight percentage were: 97% high manganese concentrate and 3% bentonite. The moisture content of the green pellets was controlled at 8.5%. The pellets were formed twice in a disc pelletizer, with the first pelletizing time being 5 minutes and the second pelletizing time being 15 minutes. The compressive strength of the green pellets was tested to be 15.51 N / pellet, the drop strength was 9.1 drops / pellet, the bursting temperature was greater than 600℃, and the green pellet formation rate was 74.77%.

[0071] The finished pellets have a compressive strength of 1740 N / piece, a medium-temperature reducing expansion coefficient of 9.56%, a MnO content of 79.85%, a TFe content of 3.89%, a SiO2 content of 10.21%, a CaO content of 7.67%, an Al2O3 content of 4.26%, and a MgO content of 1.97%.

[0072] As can be seen from Examples 1, 2, and 3, with the further increase of the bentonite ratio, the compressive strength, drop strength, compressive strength, and medium-temperature reduction expansion rate of green pellets and molten pellets gradually improve. However, the MnO content in the high-manganese concentrate pellets gradually decreases. The addition of manganese ore blocks to blast furnace smelting is mainly to utilize the effective component MnO. The preferred bentonite ratio is 2.5% to ensure that the MnO content in the finished pellets is above 80%.

[0073] Based on the high-manganese pellet composition of Example 2, the blast furnace on-site composite charge (high-titanium sinter + full vanadium-titanium pellets) was blended with 0%, 1%, and 2% of the high-temperature slag of the composite charge, and the chemical composition of the high-temperature slag of the composite charge was tested, as shown in Table 3. The composite charge with 0% high-manganese pellets is the blast furnace baseline example, and the composite charges with 1% and 2% high-manganese pellets are based on the results of Examples 1 and 2 above.

[0074]

[0075] Table 3

[0076] As shown in Table 3, with the increase of the proportion of high manganese concentrate pellets, the MnO content in the overall furnace charge slag gradually increases, while the Ti(C,N) and TFe contents gradually decrease. This indicates that the addition of high manganese pellets to the blast furnace smelting of high titanium vanadium-titanium ore can effectively reduce the over-reduction of TiO2 in the slag, reduce the amount of iron carried in the slag, increase the output of molten iron, and strengthen the blast furnace smelting.

[0077] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Any modifications or equivalent substitutions made to the present invention without departing from the spirit and scope thereof should be covered within the protection scope of the claims of the present invention.

Claims

1. A method for preparing manganese-containing pellets, characterized in that, include: Step a: Crush the high-manganese lump ore to less than 1 mm, add water for fine grinding and dry treatment to obtain high-manganese concentrate, wherein the proportion of particles smaller than 0.074 mm in the obtained high-manganese concentrate is greater than 60%; Step b: Mix the high-manganese concentrate and bentonite evenly according to a preset ratio to obtain a mixture; Step c: Add the mixture to the disc pelletizer and obtain pellet cores of 1-2 mm in the drip pelletizing mode; Step d: Based on the control of the core of the pellet, the moisture ratio and pelletizing time of the disc pelletizer are added to ensure that the remaining mixture of the mixture is uniformly coated on the outer layer of the core of the pellet, thereby obtaining manganese-containing pellets, which include: Step d1: Based on the control of the core of the pellet, add water to the disc pelletizer to make the moisture content of the finished green pellets 8% to 10%, and control the pelleting time to 15 to 30 minutes, so that the remaining mixture of the mixture is evenly coated on the outer layer of the core of the pellet to obtain green pellets; Step d2: The green pellets are subjected to particle size screening to obtain high manganese concentrate green pellets with a particle size of 8-16 mm; Step d3: The high-manganese concentrate green pellets are dried, roasted, and cooled. Specifically, the high-manganese concentrate green pellets are dried at a temperature of 150-300℃ for 2-3 hours. After drying, they are preheated in a muffle furnace at a temperature of 800-1000℃ for 15-25 minutes. After preheating, they are roasted at a temperature of 1150-1300℃ with air introduced for 20-30 minutes. After roasting, air is introduced into the muffle furnace for cooling to obtain manganese-containing ore pellets.

2. The method for preparing manganese-bearing pellets according to claim 1, characterized in that, Step a includes: Step a1: Crush the high-manganese lump ore and grind it with water to obtain a slurry; Step a2: Let the slurry stand and remove the clear liquid from its surface; Step a3: Dry, grind and sieve the slurry after removing the clear liquid to obtain high manganese concentrate.

3. The method for preparing manganese-bearing pellets according to claim 2, characterized in that, Step a1 includes: Water is added to the crushed high-manganese ore to make the high-manganese ore concentration 60-65%, and then it is finely ground for 8-10 minutes to obtain a slurry with a particle size of less than 0.074 mm accounting for 60-70%.

4. The method for preparing manganese-bearing pellets according to claim 2, characterized in that, Step a2 includes: After placing the slurry in a slurry tank and letting it stand for 3-5 minutes, remove the clear liquid from the surface of the slurry.

5. The method for preparing manganese-bearing pellets according to claim 2, characterized in that, Step a3 includes: After removing the clarified liquid, the slurry is dried at 150°C for 40-50 hours, then milled and sieved through a 100-mesh screen to obtain high-manganese concentrate.

6. The method for preparing manganese-bearing pellets according to claim 1, characterized in that, Step b includes: The high manganese concentrate and bentonite are mixed evenly for 10 minutes at a ratio of (95-99%): (1-5%) to obtain a mixture.

7. A method for blast furnace smelting, characterized in that, This includes the method for preparing manganese-containing pellets as described in any one of claims 1-6.

8. The blast furnace smelting method according to claim 7, characterized in that, Also includes: The proportion of manganese-containing pellets transferred to the feeding belt is controlled so that the manganese-containing pellets are uniformly mixed with the iron-containing pellets and / or sinter on the feeding belt before being fed into the blast furnace for smelting.

9. The blast furnace smelting method according to claim 8, characterized in that, The ratio includes a weight percentage of 1% to 3%.

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