Treatment and resource utilization method of high-titanium blast furnace slag

Abstract

The invention relates to the technical field of metallurgical waste slag treatment, and discloses a high-titanium blast furnace slag treatment and resource utilization method, which comprises the following steps: adding industrial barium sulfate and limestone into a preheated electric furnace, and introducing high-temperature molten blast furnace slag into the electric furnace to uniformly mix; the electric furnace is started for heating, and heat preservation is conducted for 1-3 h after heating; heating is stopped, slag is discharged, and molten slag is poured into a water quenching slag pool to be subjected to water quenching quenching treatment; water-quenched slag is filtered out and aired, and the water-quenched slag is ground into ore pulp through a wet ball mill; metallic iron in the ore pulp is separated out through magnetic separation, and tailing pulp and concentrate pulp are obtained through further reselection of the ore pulp; filtering and drying the concentrate pulp to obtain a titanium-rich material, carrying out acid leaching treatment on the titanium-rich material, filtering to obtain a titanium-rich solution and barium sulfate, and recycling the barium sulfate; and further removing impurities from the titanium-rich solution to obtain titanium dioxide. According to the method, titanium resources in the blast furnace slag are efficiently recycled, and meanwhile barium sulfate is adopted as a medium to be recycled.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgical waste slag treatment, and in particular to a method for treating and recycling high-titanium blast furnace slag. Background Art

[0002] High-titanium blast furnace slag is the main by-product of blast furnace smelting of vanadium-titanium magnetite. The properties of high-titanium blast furnace slag are different from those of ordinary blast furnace slag. The titanium dioxide content is about 23%. The titanium in the slag combines with calcium to form a perovskite phase, which results in the high-titanium blast furnace slag not having a volcanic ash activity basis and cannot be used to prepare highly active slag powder for use in the building materials field. At present, high-titanium blast furnace slag mainly uses a hot pouring and slow cooling process to form heavy slag slag blocks, which are then prepared through a multi-stage crushing and magnetic separation process to prepare sand and gravel aggregate products for use in the commercial concrete field. The level of comprehensive resource utilization is not high. In addition, there are blast furnace slag titanium extraction processes including the preparation of titanium silicon alloys, acid-base leaching, high-temperature carbonization-low-temperature chlorination, and combined smelting and selection. The titanium-silicon alloy method has relatively limited applications and low demand; the acid-base method consumes a large amount of leaching agent and produces secondary pollution; the precise control of carbon thermal reduction process parameters is difficult to master, and there is also the problem of difficult treatment of chlorinated residues; and the combination of beneficiation and smelting is currently a more feasible titanium extraction process route. For example, titanium in titanium-containing blast furnace slag at high temperature is precipitated in the perovskite phase + flotation. This process has the advantages of cleanliness, low cost and large processing capacity, but the perovskite grain size is uneven and the sorting is difficult, resulting in a low titanium recovery rate.

[0003] Therefore, there is a need in the prior art for improving the treatment and resource utilization methods of high-titanium blast furnace slag. Summary of the invention

[0004] In view of this, the purpose of the embodiment of the present invention is to provide a method for treating and recycling high-titanium blast furnace slag, which efficiently recovers the titanium resources in the blast furnace slag and uses barium sulfate as a medium for recycling.

[0005] Based on the above purpose, the embodiment of the present invention provides a method for processing and resource utilization of high-titanium blast furnace slag. S1: Add industrial barium sulfate and limestone into the preheated electric furnace, and then introduce high-temperature molten blast furnace slag into the electric furnace for mixing; S2 starts the electric furnace to heat up, and then keeps the temperature for 1-3 hours; S3 stops heating and slag is discharged, and the molten slag is poured into a water quenching slag pool for water quenching and rapid cooling; S4 filters out the water-quenched slag and dries it, and grinds the water-quenched slag into slurry using a wet ball mill; S5 selects metallic iron from the ore pulp by magnetic separation, and further reselects the ore pulp to obtain tailings pulp and concentrate pulp; S6 filters and dries the concentrate slurry to obtain titanium-rich material, performs acid leaching on the titanium-rich material, obtains titanium-rich liquid and barium sulfate after filtration, and the barium sulfate is returned to S1 for recycling; The S7 titanium-rich liquid is further purified to obtain titanium dioxide.

[0006] In some embodiments, in S1, the amount of industrial barium sulfate added is 20% to 50% of the amount of blast furnace slag, and the amount of limestone added is 0 to 10% of the amount of blast furnace slag, by mass percentage.

[0007] In some embodiments, in S1, the temperature of the high temperature molten blast furnace slag is 1200-1350°C.

[0008] In some embodiments, in S2, the temperature is increased to 1550-1650°C.

[0009] In some embodiments, in S3, the amount of slag discharged is 70% to 80% of the total slag amount, and the amount of slag remaining in the electric furnace is 20% to 30%, measured by volume percentage.

[0010] In some embodiments, in S4, the filtered water-quenched slag has a particle size range of 0-5 mm and is ground to a particle size of 350 mesh or more after ball milling.

[0011] In some embodiments, in S5, the tailings slurry is filtered, dried, and then dispersed and homogenized to obtain slag powder.

[0012] In some embodiments, the tailings slurry is dehydrated using a filter press to a moisture content of less than 15% and then filtered.

[0013] In some embodiments, drying is performed in a drying kiln at a drying temperature of 150-300°C.

[0014] In some embodiments, in S6, acid leaching is performed using sulfuric acid with a concentration of 60% to 90%.

[0015] The present invention has at least the following beneficial technical effects: The present invention aims at the problems that the current high-titanium blast furnace slag has poor volcanic ash activity, TiO2 in the slag is not recycled, and the overall resource comprehensive utilization level is low, and a method for processing and resource utilization of high-titanium blast furnace slag is proposed. Barium sulfate and limestone are introduced into high-temperature molten high-titanium blast furnace slag, and the TiO2 in the slag is chemically combined with BaSO4 to form barium titanate through high-temperature coupling. The CaO component in the slag is released and combined with SiO2 and Al2O3 in the slag. The treated mixed slag is quenched by water quenching, and the calcium aluminosilicate phase forms a glass body with a volcanic ash activity basis. After the water quenching product is wet-ground, magnetic separation is used to select iron, and barium titanate minerals are selected by gravity selection. Titanium-rich liquid and barium sulfate are obtained by sulfuric acid leaching, so that titanium in the slag can be recycled. The by-product barium sulfate is returned as a raw material, and the tailings obtained by gravity selection are used as slag micropowder after drying. The method of the present invention can make efficient use of the sensible heat resources of high-titanium blast furnace slag, convert low-activity metallurgical waste slag into high-activity slag micropowder, turning waste into treasure, and not only efficiently recover the titanium resources in the blast furnace slag, but also use barium sulfate as a medium for recycling. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0017] Figure 1 This is a schematic diagram of an embodiment of the method for processing and resource utilization of high-titanium blast furnace slag provided by the present invention. DETAILED DESCRIPTION

[0018] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0019] The terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions; the terms "first", "second", etc. in the specification and claims of the present invention or the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0020] In addition, reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0021] The present invention provides a method for processing and resource utilization of high-titanium blast furnace slag, comprising: S1: Add industrial barium sulfate and limestone into the preheated electric furnace, and then introduce high-temperature molten blast furnace slag into the electric furnace for mixing; S2 starts the electric furnace to heat up, and then keeps the temperature for 1-3 hours; S3 stops heating and slag is discharged, and the molten slag is poured into a water quenching slag pool for water quenching and rapid cooling; S4 filters out the water-quenched slag and dries it, and grinds the water-quenched slag into slurry using a wet ball mill; S5 selects metallic iron from the ore pulp by magnetic separation, and further reselects the ore pulp to obtain tailings pulp and concentrate pulp; S6 filters and dries the concentrate slurry to obtain titanium-rich material, performs acid leaching on the titanium-rich material, obtains titanium-rich liquid and barium sulfate after filtration, and the barium sulfate is returned to S1 for recycling; The S7 titanium-rich liquid is further purified to obtain titanium dioxide.

[0022] The equipment of this process mainly includes electric furnace, slag water quenching system, slag grab, wet ball mill system, magnetic separator, gravity separation equipment, filter press, drying kiln, acid leaching tank, finished product silo, etc.

[0023] The theoretical basis of the method of the present invention is to chemically combine TiO2 and BaSO4 in the slag to form barium titanate through high temperature coupling: BaSO4→BaO+SO3↑ BaO+TiO2→BaTiO3 The CaO component in the slag is released and combined with SiO2 and Al2O3 in the slag. The treated mixed slag is quenched by water, and the calcium aluminosilicate phase forms a glassy body: CaO+SiO2→CaSiO3 CaO+Al2O3→Ca Al2O4 BaTiO3+2H2SO4→BaSO4↓+TiOSO4+2H2O Further, in S1, the temperature of the molten high-titanium blast furnace slag is 1200-1350°C, and in terms of mass percentage, it includes TiO2 22%-23%, CaO 28%-32%, and SiO2 25%-28%. Industrial barium sulfate: barium sulfate with a purity of more than 90% and a particle size of more than 200 mesh.

[0024] In terms of mass percentage, the amount of industrial barium sulfate added is 20% to 50% of the blast furnace slag, and the amount of limestone added is 0 to 10% of the blast furnace slag. In the process of introducing high-temperature molten blast furnace slag into the electric furnace, the materials are stirred and mixed through the impact of the molten blast furnace slag.

[0025] Furthermore, in S2, the temperature is raised to 1550-1650°C, and the slag is homogenized by the oscillation of the electrode arc.

[0026] Furthermore, in S3, the slag discharge amount is 70% to 80% of the total slag amount, and the slag remaining in the electric furnace is 20% to 30% by volume. The slag remaining in the electric furnace can improve the smelting capacity of the electric furnace and save energy.

[0027] Further, in S4, the filtered water-quenched slag has a particle size range of 0-5 mm and is ground to a particle size of more than 350 mesh after ball milling.

[0028] Furthermore, in S5, the tailings slurry is filtered, dried, and then dispersed and homogenized to obtain slag powder, which is stored in a silo. The active slag powder product is mainly used in the field of commercial concrete. The main product indicators are: 1) Specific surface area 400m 2 / kg or more; 2) activity index is above 95%. In some embodiments, the tailings slurry is dehydrated by a filter press to a moisture content of less than 15% and then filtered. A drying kiln is used for drying at a drying temperature of 150-300°C.

[0029] In some embodiments, the water-quenched slag particles are fished out of the water-quenched slag pool by a grab bucket and left to air naturally. The water-quenched slag is ground into a slurry with a particle size of more than 350 mesh by a wet ball mill. The metallic iron in the slurry is selected by a permanent magnetic drum magnetic separator.

[0030] Further, in S6, acid leaching is performed using sulfuric acid with a concentration of 60% to 90%.

[0031] The present invention will be further explained below in conjunction with specific embodiments.

[0032] Example 1 Preheat the electric furnace, add dried and dehydrated anhydrous industrial barium to the electric furnace, control the amount of industrial sodium sulfate added to 50% (mass percentage) of the blast furnace slag, and then add 10% limestone. Introduce the high-temperature molten blast furnace slag at 1450℃ just out of the blast furnace into the electric furnace, and stir and mix the materials through the impact of the blast furnace slag. The electric furnace is started, the electrode sinks into the slag pool, and the power is supplied for heating. After the temperature rises to 1600℃, it is kept warm for 2h, and the slag is homogenized through the arc oscillation of the electrode. The electric furnace stops heating, lifts the electrode, and then discharges the slag. The slag is directly poured into the water quenching slag pool for water quenching and rapid cooling. 30% of the slag is left in the electric furnace (slag retention operation, improving the smelting capacity of the electric furnace and saving energy consumption). The electric furnace repeats the above operation mode. Use a grab to remove the water-quenched granular slag (0~5mm) from the water-quenching slag pool and let it dry naturally. A wet ball mill is used to grind the water-quenched slag into a slurry with a particle size of more than 350 mesh. A permanent magnetic drum magnetic separator is used to select the metallic iron in the slurry. A gravity separation process is used to select the titanium-rich material (barium titanate) in the slurry, and the gravity separation equipment uses a spiral chute. After dehydration and drying, the selected titanium-rich material (barium titanate) is acid-leached with 90% sulfuric acid, filtered and separated to obtain barium sulfate precipitate and titanium-rich liquid. The titanium-rich liquid is impurity-removed using existing processes to prepare titanium dioxide. Barium sulfate is returned as raw material. The tailings slurry after gravity separation is dehydrated to a moisture content of less than 15% using a filter press. It is then dried in a drying kiln (300°C) to obtain an active slag micropowder product, which is stored in a silo. The active slag micropowder product is mainly used in the field of commercial concrete. Main indicators: The recovery rate of titanium in the whole process reaches 78%, and the specific surface area of ​​slag micropowder is 415m 2 / kg, activity index 97.5%.

[0033] Example 2 Preheat the electric furnace, add dried and dehydrated anhydrous industrial barium into the electric furnace, and control the amount of industrial sodium sulfate added to 20% (mass percentage) of the blast furnace slag. Introduce the high-temperature molten blast furnace slag at 1450℃ just out of the blast furnace into the electric furnace, and stir and mix the materials through the impact of the blast furnace slag. The electric furnace is started, the electrode sinks into the slag pool, and the power is supplied for heating. After the temperature rises to 1550℃, it is kept warm for 3 hours, and the slag is homogenized by the arc oscillation of the electrode. The electric furnace stops heating, lifts the electrode, and then discharges the slag. The slag is directly poured into the water quenching slag pool for water quenching and rapid cooling. 30% of the slag is left in the electric furnace (slag retention operation, improving the smelting capacity of the electric furnace and saving energy consumption). The electric furnace repeats the above operation mode. Use a grab to remove the water-quenched granular slag (0~5mm) from the water-quenching slag pool and let it dry naturally. Use a wet ball mill to grind the water-quenched slag into a slurry with a particle size of more than 350 mesh. A permanent magnetic drum magnetic separator is used to select metallic iron in the ore pulp. A gravity separation process is used to select titanium-rich materials (barium titanate) in the ore pulp, and a spiral chute is used as the gravity separation equipment. After the selected titanium-rich materials (barium titanate) are dehydrated and dried, they are acid-leached with 60% sulfuric acid, filtered and separated to obtain barium sulfate precipitate and titanium-rich liquid. The titanium-rich liquid is impurity-removed using existing processes to prepare titanium dioxide. The barium sulfate is returned as raw material. The tailings slurry after gravity separation is dehydrated to a moisture content of less than 15% using a filter press. It is then dried in a drying kiln (300°C) to obtain an active slag micropowder product, which is stored in a silo. The active slag micropowder product is mainly used in the field of commercial concrete. Main indicators: The recovery rate of titanium in the whole process reaches 69%, and the specific surface area of ​​the slag micropowder is 410m 2 / kg, activity index 95%.

[0034] Example 3 Preheat the electric furnace, add dried and dehydrated anhydrous industrial barium to the electric furnace, control the amount of industrial sodium sulfate added to 30% (mass percentage) of the blast furnace slag, and then add 5% limestone. Introduce the high-temperature molten blast furnace slag at 1450℃ just out of the blast furnace into the electric furnace, and stir and mix the materials through the impact of the blast furnace slag. The electric furnace is started, the electrode sinks into the slag pool, and the power is supplied for heating. After the temperature rises to 1650℃, it is kept warm for 1h, and the slag is homogenized through the arc oscillation of the electrode. The electric furnace stops heating, lifts the electrode, and then discharges the slag. The slag is directly poured into the water quenching slag pool for water quenching and rapid cooling. 20% of the slag is left in the electric furnace (slag retention operation, improving the smelting capacity of the electric furnace and saving energy consumption). The electric furnace repeats the above operation mode. Use a grab to remove the water-quenched granular slag (0~5mm) from the water-quenching slag pool and let it dry naturally. A wet ball mill is used to grind the water-quenched slag into a slurry with a particle size of more than 350 mesh. A permanent magnetic drum magnetic separator is used to select the metallic iron in the slurry. A gravity separation process is used to select the titanium-rich material (barium titanate) in the slurry, and a shaking table is used for the gravity separation equipment. After dehydration and drying, the selected titanium-rich material (barium titanate) is acid-leached with 70% sulfuric acid, filtered and separated to obtain barium sulfate precipitate and titanium-rich liquid. The titanium-rich liquid is impurity-removed using existing processes to prepare titanium dioxide. Barium sulfate is returned as raw material. The tailings slurry after gravity separation is dehydrated to a moisture content of less than 15% using a filter press. It is then dried in a drying kiln (150°C) to obtain an active slag micropowder product, which is stored in a silo. The active slag micropowder product is mainly used in the field of commercial concrete. The titanium recovery rate of the whole process reaches 75%, and the specific surface area of ​​the slag micropowder is 405m 2 / kg, activity index 95.5%.

[0035] The above are exemplary embodiments disclosed in the present invention, but it should be noted that various changes and modifications may be made without departing from the scope disclosed in the embodiments of the present invention as defined in the claims. The functions, steps and / or actions of the method claims according to the disclosed embodiments described herein do not need to be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or required in individual form, they may also be understood as multiple unless explicitly limited to the singular.

[0036] It should be understood that, as used herein, the singular forms "a", "an" are intended to include the plural forms as well, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" refers to any and all possible combinations including one or more of the associated listed items.

[0037] The serial numbers of the embodiments disclosed in the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0038] A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the above embodiments of the present invention, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.

Claims

1. A method for processing and resource utilization of high-titanium blast furnace slag, characterized in that: include: S1: adding industrial barium sulfate and limestone into a preheated electric furnace, and then introducing high-temperature molten blast furnace slag into the electric furnace for mixing; S2 starts the electric furnace to heat up, and keeps the temperature for 1 to 3 hours after heating up; S3 stops heating and slag is discharged, and the molten slag is poured into a water quenching slag pool for water quenching and rapid cooling; S4: filtering out the water-quenched slag and drying it, and grinding the water-quenched slag into slurry using a wet ball mill; S5 selects metallic iron from the ore pulp by magnetic separation, and further reselects the ore pulp to obtain tailings pulp and concentrate pulp; S6 filters and dries the concentrate slurry to obtain a titanium-rich material, performs acid leaching on the titanium-rich material, obtains a titanium-rich liquid and barium sulfate after filtration, and the barium sulfate is returned to S1 for recycling; The titanium-rich liquid in S7 is further impurity-removed to obtain titanium dioxide.

2. The method for processing and resource utilization of high-titanium blast furnace slag according to claim 1, characterized in that: In S1, the amount of industrial barium sulfate added is 20% to 50% of the amount of blast furnace slag, and the amount of limestone added is 0 to 10% of the amount of blast furnace slag, in terms of mass percentage.

3. The method for processing and resource utilization of high-titanium blast furnace slag according to claim 1, characterized in that: In S1, the temperature of the high temperature molten blast furnace slag is 1200-1350°C.

4. The method for processing and resource utilization of high-titanium blast furnace slag according to claim 1, characterized in that: In S2, the temperature is raised to 1550~1650°C.

5. The method for processing and resource utilization of high-titanium blast furnace slag according to claim 1, characterized in that: In S3, the slag discharge amount is 70%~80% of the total slag amount in volume percentage, and the slag remaining in the electric furnace is 20%~30%.

6. The method for processing and resource utilization of high-titanium blast furnace slag according to claim 1, characterized in that: In S4, the filtered water-quenched slag has a particle size range of 0-5 mm and is ground to a particle size of more than 350 mesh after ball milling.

7. The method for processing and resource utilization of high-titanium blast furnace slag according to claim 1, characterized in that: In S5, the tailings slurry is filtered, dried, and then dispersed and homogenized to obtain slag fine powder.

8. The method for processing and resource utilization of high-titanium blast furnace slag according to claim 7, characterized in that: The tailings slurry is dehydrated by a filter press to a moisture content of less than 15% and then filtered.

9. The method for processing and resource utilization of high-titanium blast furnace slag according to claim 7, characterized in that: The drying is carried out in a drying kiln at a drying temperature of 150~300℃.

10. The method for processing and resource utilization of high-titanium blast furnace slag according to claim 1, characterized in that: In S6, 60% to 90% concentration of sulfuric acid is used for acid leaching.

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