Method for obtaining calcium ferrite and magnesium ferrite from liquid steel slag

Abstract

The invention relates to the technical field of waste resource recycling, in particular to a method for obtaining calcium ferrite and magnesium ferrite from liquid steel slag. The method comprises the following steps: adding liquid steel slag and iron oxide micro-powder into a steel slag tank, uniformly mixing, covering and sealing, and reacting; after the reaction is finished, impacting the steel slag with high-pressure water, and sieving to obtain an undersize material and an oversize material; the undersize materials and the oversize materials are subjected to magnetic separation, crushing, magnetic separation and screening treatment, and non-iron-containing materials are obtained through separation; sieving non-iron-containing materials, and circularly crushing undersize materials until all the materials are sieved; performing shaking separation to obtain ferrite; and grinding and screening to obtain materials enriched with calcium ferrite and magnesium ferrite. According to the method, the iron oxide micro powder is added into the liquid steel slag, so that free calcium oxide and free magnesium oxide in the liquid steel slag can be effectively converted into calcium ferrite and magnesium ferrite, the separation of calcium ferrite and magnesium ferrite is simply and effectively realized, and the resource utilization rate is increased.

Description

Technical Field

[0001] The invention relates to the technical field of waste resource recycling, in particular to a method for obtaining calcium ferrite and magnesium ferrite from liquid steel slag. Background Art

[0002] During the converter steelmaking process, 8-10% liquid slag is produced, and the liquid slag mostly contains 5-10% free calcium oxide, 5-10% free magnesium oxide, 8-10% calcium ferrite and 8-10% magnesium ferrite.

[0003] The free calcium oxide and free magnesium oxide in the liquid steel slag will hydrolyze when it encounters water, resulting in a waste of free calcium oxide and free magnesium oxide resources. The reaction of free calcium oxide and free magnesium oxide with water is a long process, generally lasting 6 to 8 months; when the free calcium oxide and free magnesium oxide remaining in the steel slag react with water, the volume expansion of free calcium oxide is 98%, and the volume expansion of free magnesium oxide is 148%. Therefore, steel slag cannot be well used in related industries such as construction at present, mainly because the state of steel slag is unstable, and the reaction of free calcium oxide and free magnesium oxide with water will cause the steel slag to burst. At the same time, the calcium ferrite and magnesium ferrite contained in the steel slag have not been well used, resulting in a certain degree of resource waste.

[0004] Therefore, it is necessary to provide a method for effectively utilizing free calcium oxide and free magnesium oxide in liquid steel slag. Summary of the invention

[0005] The first object of the present invention is to provide a method for obtaining calcium ferrite and magnesium ferrite from liquid steel slag, which can effectively extract calcium ferrite and magnesium ferrite from steel slag and improve resource utilization.

[0006] The present invention provides a method for obtaining calcium ferrite and magnesium ferrite from liquid steel slag, comprising the following steps:

[0007] S1. Add liquid slag and iron oxide powder into the slag tank, mix them evenly in the slag tank, and then cover and seal the slag tank for reaction. This step can reduce the heat dissipation of the slag, and the temperature in the slag tank can reach the reaction temperature without external heating, which saves energy and is simple and convenient to operate.

[0008] In the slag tank, the heat of the liquid slag is used to convert the iron oxide powder, free calcium oxide and free magnesium oxide into corresponding iron acid. The following chemical reaction occurs during this process, and the reaction equations are shown in (1) and (2):

[0009] Fe2O3+f-CaO=CaFe2O4 (1);

[0010] Fe2O3+f-MgO=MgFe2O4 (2);

[0011] S2. After the reaction is completed, the slag in the slag tank is turned over to the vibration table, and the slag is impacted with high-pressure water. After the impact, the slag is sieved to obtain the undersize material and the oversize material, and the temperature is reduced respectively;

[0012] S3. The undersize material and the oversize material are subjected to magnetic separation, crushing, screening and magnetic separation to obtain medium- and high-grade iron-containing materials, low-grade iron-containing materials and non-iron-containing materials;

[0013] S4. The non-iron-containing material obtained in step S3 is sieved and crushed again, sieved, and the material on the sieve is returned to the cyclic crushing until all the materials are sieved;

[0014] S5. The material finally sieved in step S4 is shaken and separated to obtain a lower layer of ferrite and an upper layer of silicate;

[0015] S6. Grind and sieve the ferrite obtained in step S5 to obtain a material enriched in calcium ferrite and a material enriched in magnesium ferrite.

[0016] Preferably, the mass of the iron oxide powder in step S1 is 20-30% of the mass of the liquid slag. The reaction can be carried out when the Fe2O3 content in the iron oxide powder is greater than 50%, thereby reducing production costs.

[0017] Preferably, in step S1, the temperature in the slag pot is 1200-1400° C., and the slag pot is covered and sealed for 3-5 hours.

[0018] Preferably, the water pressure of the high-pressure water in step S2 is 5-8 atmospheres.

[0019] Preferably, the mesh size of the sieve used for screening in step S2 is 120-150 mm.

[0020] Preferably, the screen in step S2 is tilted, a first cooling pool is provided below the screen, a second cooling pool is provided in the tilted extension direction of the bottom end of the screen, the material under the screen falls into the first cooling pool, and the material on the screen slides along the screen to the second cooling pool for cooling treatment.

[0021] Preferably, the steps of step S3 are: screening, crushing and magnetically separating the oversize material that has been cooled in the second cooling pool in step S2 to obtain high-grade iron-containing material and residual material; mixing the residual material with the undersize material that has been cooled in the first cooling pool and then subjecting it to magnetic separation to separate low-iron-containing material and non-iron-containing material.

[0022] The specific steps of the preferred step S3 are: the oversize material cooled in the second cooling pool in step S2 is screened through a 150 mm × 150 mm screen to separate the oversize material and the undersize material, the oversize material is magnetically separated through a 800-1000 Gauss magnetic separation device to separate high-grade iron-containing material and magnetic separation residue, the magnetic separation residue is crushed by a crushing device, and after crushing, it is screened through a 150 mm × 150 mm screen, and the crushing, screening and magnetic separation processes are repeated; finally, the high-grade iron-containing material and the undersize material are obtained;

[0023] The above-mentioned undersize material and the undersize material cooled in the first cooling pool are mixed and then magnetically separated. First, the undersize material is magnetically separated by 800-1000 Gauss magnetic separation equipment to separate medium-grade iron-containing materials, and the remaining materials are magnetically separated again by 2800-3200 Gauss magnetic separation equipment to separate low-iron materials and non-iron materials. The iron in the above-mentioned iron-containing materials is a strongly magnetic iron-containing substance.

[0024] Preferably, the mesh size of the sieve used for the initial screening in step S4 is 130-150 mm, and the mesh size of the sieve used for the subsequent screening is 5-10 mm.

[0025] Preferably, the specific steps of step S6 include: grinding the ferrite obtained in step S5, sieving with 6-mesh and 60-mesh sieves in turn, grinding the material on the 6-mesh sieve again until it completely passes through the 6-mesh sieve, and finally obtaining a magnesium ferrite enriched material with a size of 6-60 mesh and a calcium ferrite enriched material with a size less than 60 mesh. The magnesium ferrite content in the magnesium ferrite enriched material is 50-55%, and the calcium ferrite content in the calcium ferrite enriched material is 50-55%.

[0026] It is preferred that the material grinding time be controlled within 25 to 30 minutes by controlling the material feeding speed and the amount of flushing water during grinding.

[0027] Preferably, the magnesium ferrite enriched material and the calcium ferrite enriched material in step S6 are dried until the moisture content is less than 1%.

[0028] Beneficial effects:

[0029] The present invention can effectively convert free calcium oxide and free magnesium oxide in the liquid steel slag into calcium ferrite and magnesium ferrite by adding iron oxide powder into the liquid steel slag. After crushing, magnetic separation and screening processes, a shaking table is used to separate ferrites by using the difference in specific gravity; calcium ferrite and magnesium ferrite are separated by using the difference in strength of the materials during the grinding process. The present invention realizes the separation of calcium ferrite and magnesium ferrite through simple and effective steps, which is convenient for subsequent resource recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0031] Figure 1 This is a schematic diagram of the process flow of Example 1 of the present invention;

[0032] Figure 2 This is a structural diagram of the vibration granulation tank in Example 1 of the present invention.

[0033] Description of reference numerals:

[0034] 1- slag tank, 2- train track, 3- vibrating table, 4- high pressure water gun, 5- screen, 6- first cooling pool, 7- second cooling pool. DETAILED DESCRIPTION

[0035] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0036] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form also includes the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this description, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0037] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] The mass fractions of the components to be extracted from the liquid steel slag used in the embodiment of the present invention are as follows: 6.19% of free calcium oxide, 8.72% of free magnesium oxide, 9.18% of calcium ferrite and 8.49% of magnesium ferrite.

[0039] Example 1

[0040] A method for obtaining calcium ferrite and magnesium ferrite from liquid steel slag comprises the following steps:

[0041] S1. Add liquid steel slag after adding iron oxide powder to the steel slag tank 1, the mass of the iron oxide powder is 25% of the mass of the liquid steel slag; the liquid steel slag impacts the iron oxide powder so that the two are evenly mixed in the steel slag tank 1, and the steel slag tank 1 is covered and sealed for 4.5 hours to react, during which the temperature in the steel slag tank 1 is 1300-1400°C; this step can reduce the heat dissipation of the steel slag, and the temperature in the steel slag tank 1 can reach the reaction temperature without external heating, saving energy, and the operation is simple and convenient.

[0042] The Fe2O3 content of the iron oxide micropowder used is 59.67%, the residue on the 200-mesh sieve accounts for 0.37%, and the moisture content is 0.08%.

[0043] In the slag tank 1, the heat of the liquid slag is used to convert the iron oxide powder, free calcium oxide and free magnesium oxide into corresponding iron acid products. The following chemical reaction occurs during this process, and the reaction equations are shown in (1) and (2):

[0044] Fe2O3+f-CaO=CaFe2O4 (1);

[0045] Fe2O3+f-MgO=MgFe2O4 (2);

[0046] S2. After the reaction is completed, the slag tank 1 is pulled along the train track 2 to the vicinity of the vibration granulation tank by a train, and the slag tank 1 is turned over by a crane so that the slag is turned over to the vibration table 3, and the angle between the vibration table 3 and the ground is 15°. At the same time, a horizontally arranged high-pressure water gun 4 is used to impact the slag with high-pressure water of 6 atmospheres to granulate the slag into fine particles. The vibration table 3 adopts irregular vibration up and down, left and right, and front and back to facilitate better granulation of the slag;

[0047] After impact, the material flows to the lower screen 5 under the action of impact water, and is screened by the 120mm×120mm screen 5. The screen 5 is tilted, and a first cooling pool 6 is provided below the screen 5. A second cooling pool 7 is provided in the tilted extension direction of the bottom end of the screen 5. The screen 5 is separated to obtain the material on the screen and the material under the screen; the material under the screen falls into the first cooling pool 6, and the material on the screen slides along the screen 5 to the second cooling pool 7 for cooling treatment until the material is cooled to room temperature.

[0048] S3. The oversize material cooled in the second cooling pool 7 in step S2 is screened through a 150 mm × 150 mm screen to be divided into two types of oversize and undersize materials, the oversize material is magnetically separated by a 800-1000 Gauss magnetic separation device to separate high-grade iron-containing materials and magnetic separation residues, the magnetic separation residues are crushed by a crushing device, and after crushing, they are screened through a 150 mm × 150 mm screen, and the crushing, screening and magnetic separation processes are repeated; finally, high-grade iron-containing materials and undersize residual materials are obtained;

[0049] The above-mentioned residual material under the screen and the material under the screen that has been cooled in the first cooling pool 6 are mixed and then magnetically separated. First, they are magnetically separated by a magnetic separation device of 800-1000 Gauss to separate medium-grade iron-containing materials. The remaining materials are magnetically separated again by a magnetic separation device of 2800-3200 Gauss to separate low-iron materials and non-iron-containing materials. The iron in the above-mentioned iron-containing materials is a strongly magnetic iron-containing substance.

[0050] S4. After the non-ferrous material obtained in step S3 is passed through a 150mm×150mm sieve, the material under the sieve is crushed again with a crushing equipment, sieved through a 5mm×5mm sieve, and the material on the sieve is returned to the cyclic crushing until all the materials pass through a 5mm×5mm sieve;

[0051] S5. The material finally sieved in step S4 is separated by shaking on a shaking table, and the difference in specific gravity is used to separate the lower ferrite and the upper silicate;

[0052] S6. The ferrite obtained in step S5 is ground using a MQYφ1500×3000 ball mill, and sieved using 6-mesh and 60-mesh sieves in turn. The material on the 6-mesh sieve is ground again until it completely passes through the 6-mesh sieve, and finally a magnesium ferrite enriched material with a size of 6-60 mesh and a calcium ferrite enriched material with a size less than 60 mesh are obtained. During grinding, the material feeding speed and the amount of flushing water are controlled so that the overall grinding time of the material is controlled within 28 minutes.

[0053] The magnesium ferrite content in the magnesium ferrite enriched material is 51.91%, and the calcium ferrite content in the calcium ferrite enriched material is 52.64%. The magnesium ferrite enriched material and the calcium ferrite enriched material are dried, and the moisture content of the calcium ferrite after drying is 0.67%, and the moisture content of the magnesium ferrite is 0.48%.

[0054] Example 2

[0055] A method for obtaining calcium ferrite and magnesium ferrite from liquid steel slag comprises the following steps:

[0056] S1. Add liquid steel slag after adding iron oxide powder to the steel slag tank 1, the mass of the iron oxide powder is 20% of the mass of the liquid steel slag; after the liquid steel slag impacts the iron oxide powder so that the two are evenly mixed in the steel slag tank 1, the steel slag tank 1 is covered and sealed for 3 hours to react, during which the temperature in the steel slag tank 1 is 1250-1400°C; this step can reduce the heat dissipation of the steel slag, and the temperature in the steel slag tank 1 can reach the reaction temperature without external heating, saving energy, and the operation is simple and convenient.

[0057] The Fe2O3 content of the iron oxide micropowder used is 80.21%, the residue on the 200-mesh sieve accounts for 0.54%, and the moisture content is 0.12%.

[0058] In the slag tank 1, the heat of the liquid slag is used to convert the iron oxide powder, free calcium oxide and free magnesium oxide into corresponding iron acid products. The following chemical reaction occurs during this process, and the reaction equations are shown in (1) and (2):

[0059] Fe2O3+f-CaO=CaFe2O4 (1);

[0060] Fe2O3+f-MgO=MgFe2O4 (2);

[0061] S2. After the reaction is completed, the slag tank 1 is pulled along the train track 2 to the vicinity of the vibration granulation tank by a train, and the slag tank 1 is turned over by a crane so that the slag is turned over to the vibration table 3, and the angle between the vibration table 3 and the ground is 15°. At the same time, a horizontally arranged high-pressure water gun 4 is used to impact the slag with high-pressure water of 8 atmospheres to granulate the slag into fine particles. The vibration table 3 adopts irregular vibration up and down, left and right, and front and back to facilitate better granulation of the slag;

[0062] After impact, the material flows to the lower screen 5 under the action of impact water, and is screened by the 150mm×150mm screen 5. The screen 5 is tilted, and a first cooling pool 6 is provided below the screen 5. A second cooling pool 7 is provided in the tilted extension direction of the bottom end of the screen 5. The screen 5 is separated to obtain the material on the screen and the material under the screen; the material under the screen falls into the first cooling pool 6, and the material on the screen slides along the screen 5 to the second cooling pool 7 for cooling treatment until the material is cooled to room temperature.

[0063] S3. The oversize material cooled in the second cooling pool 7 in step S2 is screened through a 150 mm × 150 mm screen to be divided into two types of oversize and undersize materials, the oversize material is magnetically separated by a 800-1000 Gauss magnetic separation device to separate high-grade iron-containing materials and magnetic separation residues, the magnetic separation residues are crushed by a crushing device, and after crushing, they are screened through a 150 mm × 150 mm screen, and the crushing, screening and magnetic separation processes are repeated; finally, high-grade iron-containing materials and undersize residual materials are obtained;

[0064] The above-mentioned residual material under the screen and the material under the screen that has been cooled in the first cooling pool 6 are mixed and then magnetically separated. First, they are magnetically separated by a magnetic separation device of 800-1000 Gauss to separate medium-grade iron-containing materials. The remaining materials are magnetically separated again by a magnetic separation device of 2800-3200 Gauss to separate low-iron materials and non-iron-containing materials. The iron in the above-mentioned iron-containing materials is a strongly magnetic iron-containing substance.

[0065] S4. After the non-iron-containing material obtained in step S3 is passed through a 150mm×150mm sieve, the material under the sieve is crushed again, sieved through an 8mm×8mm sieve, and the material on the sieve is returned to the circulated crushing until all the materials pass through an 8mm×8mm sieve;

[0066] S5. The material finally sieved in step S4 is separated by shaking on a shaking table, and the difference in specific gravity is used to separate the lower ferrite and the upper silicate;

[0067] S6. The ferrite obtained in step S5 is ground using a MQYφ1500×3000 ball mill, and sieved using 6-mesh and 60-mesh sieves in turn. The material on the 6-mesh sieve is ground again until it completely passes through the 6-mesh sieve, and finally a magnesium ferrite enriched material with a size of 6-60 mesh and a calcium ferrite enriched material with a size less than 60 mesh are obtained. During grinding, the material feeding speed and the amount of flushing water are controlled so that the overall grinding time of the material is controlled within 30 minutes.

[0068] The magnesium ferrite content in the magnesium ferrite enriched material is 52.31%, and the calcium ferrite content in the calcium ferrite enriched material is 51.36%. The magnesium ferrite enriched material and the calcium ferrite enriched material are dried, and the moisture content of the calcium ferrite after drying is 0.52%, and the moisture content of the magnesium ferrite is 0.35%.

[0069] Example 3

[0070] A method for obtaining calcium ferrite and magnesium ferrite from liquid steel slag comprises the following steps:

[0071] S1. Add liquid steel slag after adding iron oxide powder to the steel slag tank 1, the mass of the iron oxide powder is 30% of the mass of the liquid steel slag; after the liquid steel slag impacts the iron oxide powder so that the two are evenly mixed in the steel slag tank 1, the steel slag tank 1 is covered and sealed for 5 hours to react, during which the temperature in the steel slag tank 1 is 1200-1400°C; this step can reduce the heat dissipation of the steel slag, and the temperature in the steel slag tank 1 can reach the reaction temperature without external heating, saving energy, and the operation is simple and convenient.

[0072] The Fe2O3 content of the iron oxide micropowder used is 52.04%, the residue on the 200-mesh sieve accounts for 0.29%, and the moisture content is 0.21%.

[0073] In the slag tank 1, the heat of the liquid slag is used to convert the iron oxide powder, free calcium oxide and free magnesium oxide into corresponding iron acid products. The following chemical reaction occurs during this process, and the reaction equations are shown in (1) and (2):

[0074] Fe2O3+f-CaO=CaFe2O4 (1);

[0075] Fe2O3+f-MgO=MgFe2O4 (2);

[0076] S2. After the reaction is completed, the slag tank 1 is pulled along the train track 2 to the vicinity of the vibration granulation tank by a train, and the slag tank is turned over by a crane so that the slag is turned over to the vibration table 3, and the angle between the vibration table 3 and the ground is 15°. At the same time, a horizontally arranged high-pressure water gun 4 is used to impact the slag with high-pressure water of 7 atmospheres to granulate the slag into fine particles. The vibration table 3 adopts irregular vibration up and down, left and right, and front and back to facilitate better granulation of the slag;

[0077] After impact, the material flows to the lower screen 5 under the action of impact water, and is screened by the 130mm×130mm screen 5. The screen 5 is tilted, and a first cooling pool 6 is provided below the screen 5. A second cooling pool 7 is provided in the tilted extension direction of the bottom end of the screen 5. The screen 5 is separated to obtain the material on the screen and the material under the screen; the material under the screen falls into the first cooling pool 6, and the material on the screen slides along the screen 5 to the second cooling pool for cooling treatment until the material is cooled to room temperature.

[0078] S3. The oversize material cooled in the second cooling pool 7 in step S2 is screened through a 150 mm × 150 mm screen to be divided into two types of oversize and undersize materials, the oversize material is magnetically separated by a 800-1000 Gauss magnetic separation device to separate high-grade iron-containing materials and magnetic separation residues, the magnetic separation residues are crushed by a crushing device, and after crushing, they are screened through a 150 mm × 150 mm screen, and the crushing, screening and magnetic separation processes are repeated; finally, high-grade iron-containing materials and undersize residual materials are obtained;

[0079] The above-mentioned residual material under the screen and the material under the screen that has been cooled in the first cooling pool 6 are mixed and then magnetically separated. First, they are magnetically separated by a magnetic separation device of 800-1000 Gauss to separate medium-grade iron-containing materials. The remaining materials are magnetically separated again by a magnetic separation device of 2800-3200 Gauss to separate low-iron materials and non-iron-containing materials. The iron in the above-mentioned iron-containing materials is a strongly magnetic iron-containing substance.

[0080] S4. After the non-iron-containing material obtained in step S3 is passed through a 130mm×130mm sieve, the material under the sieve is crushed again, sieved through a 10mm×10mm sieve, and the material on the sieve is returned to the circulated crushing until all the materials pass through a 10mm×10mm sieve;

[0081] S5. The material finally sieved in step S4 is separated by shaking on a shaking table, and the difference in specific gravity is used to separate the lower ferrite and the upper silicate;

[0082] S6. The ferrite obtained in step S5 is ground using a MQYφ1500×3000 ball mill, and sieved using 6-mesh and 60-mesh sieves in turn. The material on the 6-mesh sieve is ground again until it completely passes through the 6-mesh sieve, and finally a magnesium ferrite enriched material with a size of 6-60 mesh and a calcium ferrite enriched material with a size less than 60 mesh are obtained. During grinding, the material feeding speed and the amount of flushing water are controlled so that the overall grinding time of the material is controlled within 25 minutes.

[0083] The magnesium ferrite content in the magnesium ferrite enriched material is 53.26%, and the calcium ferrite content in the calcium ferrite enriched material is 52.18%. The magnesium ferrite enriched material and the calcium ferrite enriched material are dried, and the moisture content of the calcium ferrite after drying is 0.48%, and the moisture content of the magnesium ferrite is 0.61%.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for obtaining calcium ferrite and magnesium ferrite from liquid steel slag, characterized in that: The following steps are involved: S1. Add liquid slag and iron oxide powder to the slag tank, mix them evenly in the slag tank, and then seal the slag tank to react; S2. After the reaction is completed, the slag in the slag tank is turned over to the vibration table, and the slag is impacted with high-pressure water. After the impact, the slag is sieved to obtain the undersize material and the oversize material, and the temperature is reduced respectively; S3. The undersize material and the oversize material are subjected to magnetic separation, crushing, screening, and magnetic separation to obtain iron-containing and non-iron-containing materials; S4. The non-iron-containing material obtained in step S3 is sieved and crushed again, sieved, and the material on the sieve is returned to the cyclic crushing until all the materials are sieved; S5. The material finally sieved in step S4 is shaken and separated to obtain the lower layer of ferrite; S6. Grind and sieve the ferrite obtained in step S5 to obtain a material enriched in calcium ferrite and a material enriched in magnesium ferrite.

2. The method according to claim 1, characterized in that In step S1, the mass of the iron oxide powder is 20-30% of the mass of the liquid slag.

3. The method according to claim 1, characterized in that In step S1, the temperature in the slag tank is 1200-1400° C., and the slag tank is sealed with a cover for 3-5 hours.

4. The method according to claim 1, characterized in that The water pressure of the high-pressure water in step S2 is 5-8 atmospheres.

5. The method according to claim 1, characterized in that The mesh size of the sieve used in the sieving in step S2 is 120-150 mm.

6. The method according to claim 1, characterized in that The screen in step S2 is tilted, a first cooling pool is provided below the screen, a second cooling pool is provided in the tilted extending direction of the bottom of the screen, the material under the screen falls into the first cooling pool, and the material on the screen slides along the screen to the second cooling pool for cooling.

7. The method according to claim 1, characterized in that The steps of step S3 are: screening, crushing and magnetically separating the oversize material that has been cooled in the second cooling pool in step S2 to obtain high-grade iron-containing material and residual material; mixing the residual material with the undersize material that has been cooled in the first cooling pool and performing magnetic separation to separate low-iron-containing material and non-iron-containing material.

8. The method according to claim 1, characterized in that In the step S4, the mesh size of the sieve used for the initial screening is 130-150 mm, and the mesh size of the sieve used for the subsequent screening is 5-10 mm.

9. The method according to claim 1, characterized in that: The specific steps of step S6 include: grinding the ferrite obtained in step S5, sieving with 6-mesh and 60-mesh sieves in turn, grinding the material on the 6-mesh sieve again until it completely passes through the 6-mesh sieve, and finally obtaining a magnesium ferrite enriched material with a size of 6-60 mesh and a calcium ferrite enriched material with a size less than 60 mesh.

10. The method according to claim 1, characterized in that The magnesium ferrite enriched material and the calcium ferrite enriched material in step S6 are dried until the moisture content is less than 1%.

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