A method and system for efficient granulation modification of fine powder of titanium-rich material

Abstract

A method and system for efficient granulation modification of fine powder of titanium-rich material, the system comprising a granulation subsystem with a high-speed shearing granulator; a drying subsystem with a drying fluidized bed, a cyclone dust collector, and a bag dust collector; and a consolidation subsystem with a cyclone preheater, a flue gas combustion chamber, a consolidation bed, a combustion heating chamber, and a cooler. The method comprises: feeding the titanium-rich material, fine powder of high-titanium slag, a binder, and water into the high-speed shearing granulator for granulation, then feeding the granulated material to the drying fluidized bed for drying, and then feeding the dried material to the multi-stage cyclone preheater for heat exchange with flue gas after deoxidation to achieve preheating, and then feeding the preheated material to the consolidation bed to obtain the product after consolidation. The advantages are: simple system structure, strong applicability; the granulation modification method relies on the pyrolysis of Ti / Fe organic binder to obtain low-valence oxides in the preheating process, and the rapid oxidation and heat release of low-valence oxides in the high-titanium slag in the consolidation process leads to local overheating and liquid phase sintering, achieving efficient consolidation and obtaining modified particles with excellent performance.

Description

Technical Field

[0001] This invention relates to a method and system for efficient granulation modification of titanium-rich fine powder. Background Technology

[0002] Titanium tetrachloride is an intermediate product in the production of titanium and its compounds, and an important raw material for the development of the titanium industry. Titanium tetrachloride can be used to produce titanium dioxide through oxidation, or to produce sponge titanium through magnesium reduction, and further to produce titanium and titanium alloys. With the rapid development of the titanium industry in recent years, the demand for titanium raw materials has been increasing. Currently, there are two main utilization pathways for titanium resources: the chlorination process and the sulfuric acid process. The chlorination process includes fluidized bed chlorination and molten salt chlorination. Fluidized bed chlorination, with its short process flow, low cost, low pollution, and high capacity, is a mainstream advanced titanium resource utilization technology. The fluidized bed chlorination process involves chlorinating titanium-containing raw materials with carbon in a fluidized bed to obtain titanium tetrachloride. It has very high requirements for raw materials, generally requiring a titanium dioxide grade of over 90% and a particle size of over 90% within the range of 75μm to 300μm. Therefore, in existing fluidized bed chlorination processes, in order to control the particle size of the raw materials, a large amount of fine titanium-rich powder is generated that cannot be utilized, resulting in low raw material utilization and the inability to recover some fine-particle titanium-rich raw materials.

[0003] The current solutions to the problem of unusable fine-grained titanium-rich raw materials mainly focus on two aspects: optimizing the chlorination furnace reactor and raw material granulation treatment. CN111908501A discloses a "chlorination furnace for fine-grained titanium-rich materials and its fluidized bed chlorination process," which uses multiple chlorination units, each with an independent air inlet pipe and control system, and an expansion section at the top of each reactor. CN103818951A discloses a "fluidized bed chlorination furnace adapted to fine-grained titanium-rich materials," which also uses an expansion section at the top of the chlorination furnace. The reduced gas velocity allows the fine-grained material to return to the main body of the chlorination furnace. In addition, the chlorine gas enters tangentially, which facilitates gas-solid separation and reduces the escape of fine particles. Both methods described above optimize the structure of the chlorination furnace reactor, primarily by adding an enlarged section at the top. Theoretically, this enlarged section should reduce the gas velocity, allowing some of the fine-grained titanium-rich feedstock to fall back into the main body of the chlorination furnace. However, due to the extremely fine particle size in this section, coupled with the high gas velocity in the reaction zone of the chlorination furnace caused by the formation of titanium tetrachloride in the concentrated phase region, the fine-grained titanium-rich feedstock is practically unable to return to the concentrated phase region and undergo the chlorination reaction.

[0004] Therefore, more research is starting from the source, granulating the raw materials to fundamentally solve the problem of fine powder utilization. For example, US2761760 discloses "a process for producing titanium tetrachloride," which uses titanium-rich material below 100 mesh, combined with fine carbon powder and a binder to form pellets, using highly reactive NOCl as the chlorinating agent, employing a fixed-bed reactor, and reducing the chlorination temperature to 400℃. However, the NOCl used in this process is expensive, has high recycling costs, and the fixed-bed reaction efficiency is low, making it difficult to apply on a large scale in production. US4187117 discloses a titanium slag-coke pre-agglomerated particle for fluidized bed chlorination, controlling the particle size of titanium slag and pitch to below 325 mesh, adding a binder, granulating with a disc granulator, controlling the pellet size between 28 mesh and 100 mesh, and thermally curing at 900℃ to 1000℃, using ferrous chloride, sodium sulfite, sodium sulfate, or nylon as the binder. CN106319246A discloses a granulation method for fine-grained titanium-rich materials. This method uses potassium hydroxide or sodium hydroxide and water to form a binder, and employs a disc granulator, fluidized bed granulator, spray granulator, extrusion granulator, compression granulator, or agglomeration granulator as granulation equipment. After drying, the granulated material is calcined at 500–1200℃ to obtain the granulated material. During the granulation process, the binder mainly uses two categories: hydrocarbon-containing organic compounds and potassium / sodium salts / alkalis. The purpose of using potassium / sodium salts / alkalis is to allow them to react with oxides in titanium slag or titanium-rich materials during high-temperature solidification, giving the solidified material a certain strength and thus preventing pulverization due to poor particle strength during fluidized bed chlorination. However, the introduction of potassium or sodium can adversely affect the refractory material of the chlorination furnace, and their salts can accumulate in the furnace. Furthermore, potassium and sodium sulfates or hydrochlorides have low melting points and can form molten salts under the operating temperature conditions of fluidized bed chlorination, thus posing a risk of loss of flow. Using hydrocarbon-containing organic materials such as coal tar, asphalt, and pulp waste liquid, although inexpensive, contains elements such as sulfur (S) and nitrogen (N), which will produce nitrogen (NO) during the consolidation roasting process. x and SO x This is detrimental to the environment. During the granulation process, the granulation equipment used, such as extrusion granulation equipment, produces particles with larger sizes, which require crushing and screening after consolidation. Although other equipment produces granules with smaller sizes that meet the requirements for fluidized bed chlorination feedstock, the granules have poor strength, making them difficult to transport and transfer, and the yield is relatively low.

[0005] Therefore, there is an urgent need to develop a more reasonable method to obtain granulated modified materials that meet the requirements of fluidized bed chlorination, thereby solving the problem of the inability to utilize fine-grained titanium-rich raw materials. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a method and system for efficient granulation modification of titanium-rich fine powder.

[0007] The technical solution of the present invention is as follows:

[0008] A high-efficiency granulation modification system for titanium-rich fine powder includes a titanium-rich material silo, a high-titanium slag fine powder silo, and a binder silo. The outlets of the titanium-rich material silo, the high-titanium slag fine powder silo, and the binder silo are connected to the inlet of the granulation equipment. The outlet of the granulation equipment is connected to the inlet of the granulation silo. The outlet of the granulation silo is connected to the inlet of the drying equipment.

[0009] Its features are: the granulation equipment is a high-speed shear granulator, and the drying equipment is a drying fluidized bed;

[0010] The air outlet of the drying equipment is connected to the cyclone dust collector; the discharge port of the cyclone dust collector is connected to the dust collection bin; the air outlet of the cyclone dust collector is connected to the bag filter; the air outlet of the bag filter is connected to the induced draft fan; the air outlet of the induced draft fan is connected to the vent pipe; and the discharge port of the bag filter is connected to the inlet of the dust collection bin.

[0011] The air inlet of the drying equipment is connected to the air outlet of the cyclone preheater, the inlet of the cyclone preheater is connected to the outlet of the drying equipment and the outlet of the flue gas combustion chamber, and the outlet of the cyclone preheater is connected to the feed inlet of the consolidated bed.

[0012] The flue gas combustion chamber inlet is connected to the solidified bed outlet and the fuel pipeline respectively; the solidified bed outlet is connected to the cooler inlet, and the solidified bed inlet is connected to the combustion heating chamber outlet; the combustion heating chamber inlet is connected to the fuel pipeline and the cooler outlet; the cooler inlet is connected to an air pipeline and a nitrogen pipeline, and the cooler outlet is connected to a discharge pipeline.

[0013] Furthermore, the discharge port of the dust collection bin is connected to the feed port of the high-speed shear granulator.

[0014] Furthermore, the inlet of the high-speed shear granulator is connected to a process water pipe.

[0015] Furthermore, the cyclone preheater is multi-stage, with the lower outlet of the higher-stage cyclone connected to the inlet of the lower-stage cyclone, and the top outlet of the lower-stage cyclone connected to the inlet of the higher-stage cyclone.

[0016] A method for efficient granulation modification of titanium-rich fine powder using the above-described system, characterized by the following steps:

[0017] (1) The titanium-rich material, high-titanium slag fine powder and binder are fed into a high-speed shear granulator and water is added. Under the action of the high-speed shear granulator, granules with a particle size of 0.15 to 2 mm are obtained.

[0018] The granulator rotor speed is 100-3000 rpm, the disc speed is 10-200 rpm, and the granulation time is 5-60 min. The binder is an organic titanium / iron binder, or a mixture of organic titanium / iron binder and organic binder. The organic binder is one or two of dextrin and carboxymethyl cellulose. The organic titanium / iron binder is at least one of titanium oxalate, ferrous oxalate, metatitanic acid, ferrous alginate, and ferrous alginate. The mass ratio of titanium-rich fine powder, high-titanium slag fine powder, binder, and water is 1:0.1-0.3:0.005-0.05:0.05-0.1.

[0019] (2) The granulated material is fed into the drying fluidized bed, and the flue gas from the multi-stage cyclone preheater is introduced into the drying fluidized bed to dry the granulated material;

[0020] (3) The dried granulated material is fed into a multi-stage cyclone preheater; the flue gas generated by the drying fluidized bed is sent into a cyclone separator and a bag filter. The flue gas after dust removal is discharged by an induced draft fan, and the collected dust is sent into a dust collection bin and then returned to the high-speed shear granulator.

[0021] The granulated material, after drying, is fed into a multi-stage cyclone preheater to exchange heat with the flue gas generated in the combustion chamber. Fuel is introduced into the combustion chamber, along with hot flue gas from the solidified bed, so that the fuel combustion consumes the oxygen in the hot flue gas. The preheated granulated material is then fed into the solidified bed, where it solidifies due to the high-temperature flue gas generated by combustion in the combustion heating chamber. After solidification, it is fed into a cooler, where a mixture of air and nitrogen is introduced to exchange heat with the high-temperature solidified material. The heated mixture is then fed into the combustion heating chamber, where fuel is introduced to burn and generate high-temperature flue gas, which is then fed into the solidified bed. After cooling, the solidified material is obtained.

[0022] Furthermore, the titanium-rich material has a TiO2 content of 70%–98%, an average particle size of 5–100 μm, a CaO content of 0–0.5%, and a MgO content of 0%–1.5%; the high-titanium slag has a TiO2 content of 70%–95%, an average particle size of 5–100 μm, a CaO content of 0–0.5%, and a MgO content of 0%–1.5%.

[0023] Furthermore, the temperature in the drying fluidized bed is 80–200°C, the apparent gas velocity is 0.5–2.0 m / s, and the average particle residence time is 5–60 min.

[0024] Furthermore, the multi-stage cyclone preheater has 2 to 6 stages, and the oxygen content of the preheated high-temperature gas after combustion deoxygenation is 0% to 5%.

[0025] Furthermore, the consolidated bed is a bubbling fluidized bed or a circulating fluidized bed, the temperature in the consolidated bed is 800-1100℃, and the average residence time of the particles is 15-60 min.

[0026] Furthermore, the cooler adopts a bubbling fluidized bed with a gas apparent velocity of 0.5 to 2.0 m / s and an average particle residence time of 30 to 120 min. The nitrogen / air volume flow rate ratio of the mixed air and nitrogen gas is (0 to 1):1.

[0027] Compared with the prior art, the present invention has the following outstanding advantages:

[0028] (1) Using organic titanium / iron as a binder, fine particles can be better aggregated into agglomerates during high-speed shear granulation, resulting in granulated materials with a high target particle size content. At the same time, these binders have low pyrolysis temperatures and can undergo pyrolysis during drying and preheating in an inert or oxygen-deficient atmosphere to form active low-valence titanium / iron oxides, which have a good reaction with the components in the titanium-rich material, facilitating the formation of corresponding solid solutions during the consolidation process. Unlike the traditional granulation material consolidation mechanism, this invention preheats the granulated material in a weakly oxidizing or neutral flue gas and then enters a high-temperature consolidation bed for oxidative consolidation. The low-valence oxides obtained by the pyrolysis of Ti / Fe organic binders during preheating, along with the rapid oxidation and exothermic reaction of the low-valence oxides in the high-titanium slag during the consolidation process, lead to local overheating and liquid-phase sintering, achieving efficient consolidation and obtaining modified particles with excellent performance.

[0029] (2) NO was avoided during the high-temperature consolidation process. x and SO x The generation of NO can be avoided by using organic compounds or organic titanium / iron that do not contain sulfur or nitrogen elements during high-temperature solidification. x and SO x The generation of.

[0030] (3) The problem of particle strength of fresh granulated materials has been solved. By adopting high-speed shear granulation, the high-speed rotation of the rotor in the shearing machine continuously throws the coarse particles formed by the fine powder into the material cylinder, thereby giving the granulated material a certain strength, which is convenient for conveying and transfer.

[0031] (4) Effectively saves energy consumption in the consolidation process. Existing technical reports rely on external heat sources to heat the consolidation material and system. This invention, however, utilizes the oxidation of low-valence iron oxides and titanium oxides in the titanium slag within the consolidation furnace, releasing a large amount of heat to provide some of the heat for the consolidation process. The combustion heating chamber can burn a small amount of fuel to maintain the heat required in the consolidation bed, thus effectively saving fuel consumption during the consolidation process. Furthermore, the heat from the consolidation material is recovered and used to heat the combustion air in the combustion heating chamber, further saving fuel consumption during consolidation. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the system for efficient granulation modification of titanium-rich fine powder according to the present invention;

[0033] In the diagram: 1-Titanium-rich material silo, 2-High-titanium slag fine powder silo, 3-Binder silo, 4-High-speed shear granulator, 5-Pelletizing silo, 6-Drying fluidized bed, 7-Cyclone dust collector, 8-Bag filter dust collector, 9-Exhaust fan, 10-Dust collection silo, 11-Multi-stage cyclone preheater, 12-Flue gas combustion chamber, 13-Consolidated bed, 14-Combustion heating chamber, 15-Cooler. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0035] Example 1

[0036] like Figure 1 As shown, the high-efficiency granulation modification system for titanium-rich fine powder includes a titanium-rich material silo 1, a high-titanium slag fine powder silo 2, and a binder silo 3. The outlets of the titanium-rich material silo 1, the high-titanium slag fine powder silo 2, and the binder silo 3 are connected to the inlet of a high-speed shear granulator 4. The inlet of the high-speed shear granulator 4 is connected to a process water pipeline, and the outlet of the high-speed shear granulator 4 is connected to the inlet of the granulation silo 5.

[0037] The discharge port of the granulation silo 5 is connected to the inlet of the drying fluidized bed 6. The air inlet of the drying fluidized bed 6 is connected to the outlet of the multi-stage cyclone preheater 11. The discharge port of the drying fluidized bed 6 is connected to the inlet of the multi-stage cyclone preheater 11. The air outlet of the drying fluidized bed 6 is connected to the cyclone dust collector 7. The discharge port of the cyclone dust collector 7 is connected to the inlet of the dust collection bin 10. The air outlet of the cyclone dust collector 7 is connected to the bag filter 8. The air outlet of the bag filter 8 is connected to the inlet of the induced draft fan 9. The discharge port of the bag filter 8 is connected to the inlet of the dust collection bin 10. The air outlet of the induced draft fan 9 is connected to the vent pipe. The discharge port of the dust collection bin 10 is connected to the inlet of the high-speed shear granulator 4.

[0038] The discharge port of the drying fluidized bed 6 is connected to the inlet of the multi-stage cyclone preheater 11, the air inlet of the multi-stage cyclone preheater 11 is connected to the outlet of the flue gas combustion chamber 12, and the discharge port of the multi-stage cyclone preheater 11 is connected to the inlet of the solidified bed 13. The cyclone preheaters in the multi-stage cyclone preheater 11 are connected as follows: when there are two stages, the lower discharge port of the first-stage cyclone is connected to the inlet of the second-stage cyclone, and the top outlet of the second-stage cyclone is connected to the inlet of the first-stage cyclone; when there are more than two stages, the lower discharge port of the higher-stage cyclone is connected to the lower-stage cyclone. The feed inlet of the first-stage cyclone is connected, and the top outlet of the lower-stage cyclone is connected to the inlet of the higher-stage cyclone; the inlet of the flue gas combustion chamber 12 is connected to the outlet of the solidified bed 13 and the fuel pipeline respectively; the outlet of the solidified bed 13 is connected to the feed inlet of the cooler 15, and the inlet of the solidified bed 13 is connected to the outlet of the combustion heating chamber 14; the inlet of the combustion heating chamber 14 is connected to the fuel pipeline and the outlet of the cooler 15; the inlet of the cooler 15 is connected to the air pipeline and the nitrogen pipeline, and the outlet of the cooler 15 is connected to the discharge pipeline.

[0039] The titanium-rich material silo 1, the high-titanium slag fine powder silo 2, the binder silo 3, the high-speed shear granulator 4, and the granulation silo 5 constitute the particle-making system, used for granulating materials; the drying fluidized bed 6, the cyclone dust collector 7, the bag filter 8, the induced draft fan 9, and the dust collection silo 10 constitute the drying subsystem, used for drying materials; the multi-stage cyclone preheater 11, the flue gas combustion chamber 12, the consolidation bed 13, the combustion heating chamber 14, and the cooler 15 constitute the consolidation subsystem, used for consolidating materials;

[0040] A method for efficient granulation modification of titanium-rich fine powder includes the following steps:

[0041] Titanium-rich material with 70% TiO2 content, particle size of 5-100 μm, CaO content of 0.5%, and MgO content of 1.5%, and high-titanium slag with 70% TiO2 content, particle size of 25-50 μm, CaO content of 0.5%, and MgO content of 1.5%, were fed into a high-speed shear granulator 4, and ferrous oxalate, carboxymethyl cellulose, and water were added. The mass ratio of the titanium-rich material powder, high-titanium slag, binder, and water was 1:0.1:0.005:0.05. The granulator rotor rotates at 1000 rpm, the disc rotates at 100 rpm, and the granulation time is 50 min, yielding particles with a diameter of 500–1000 μm. The resulting moist granulated material is fed into granulation silo 5 to obtain granules. The granules are then fed into a drying fluidized bed 6 for drying. The apparent velocity of the oxygen-deficient fluidizing gas is 0.5 m / s, and the material is dried at 200℃ for 5 min to obtain dried granules. The flue gas generated in the drying fluidized bed 6 is sent to a cyclone separator 7 and a bag filter dust collector. 8. The flue gas after dust removal is discharged through the induced draft fan 9. The collected dust is sent to the dust collection bin 10 and then returned to the high-speed shear granulator 4. The dried granulated material is sent to the two-stage cyclone preheater 11. The oxygen content in the preheating high-temperature gas is 0%. It is preheated to 500°C under the action of the hot flue gas generated in the flue gas combustion chamber 12, and then sent to the solidified bed 13. The solidified bed 13 adopts a bubbling fluidized bed. It relies on the high-temperature flue gas generated by combustion in the combustion heating chamber 14 and stays at 800°C. After 60 minutes of consolidation, the material is fed into cooler 15, which is a bubbling fluidized bed cooler. A mixed gas with a nitrogen / air volumetric flow rate ratio of 1 is introduced into cooler 15, with an apparent gas velocity of 0.5 m / s and an average particle residence time of 30 minutes. This allows for heat exchange with the high-temperature consolidated material, resulting in heating. The heated mixed gas is then introduced into combustion chamber 14, where fuel is introduced and combusted to generate high-temperature flue gas. The cooled consolidated material is then ready for use. In this embodiment, high-speed shear granulation achieves a one-time yield of 80% for target particle sizes of 500–1000 μm, with a consolidated material wear rate of 3.2% and an average particle strength of 34.1 N / mm². 2 .

[0042] Example 2

[0043] This embodiment uses the system described in Example 1 to provide a method for efficient granulation modification of titanium-rich fine powder, including the following steps:

[0044] Titanium-rich material with 98% TiO2 content, particle size of 25-50 μm, CaO content of 0.03%, and MgO content of 0.03%, and high-titanium slag with 90% TiO2 content, particle size of 25-75 μm, CaO content of 0.02%, and MgO content of 0.05%, were fed into a high-speed shear granulator 4, and ferric alginate and water were added. The mass ratio of titanium-rich material powder, high-titanium slag, binder, and water was 1:0.25:0.03:0.08. The granulator rotor rotates at 3000 rpm, the disc rotates at 200 rpm, and the granulation time is 5 minutes, yielding particles with a diameter of 150–250 μm. The resulting moist granulated material is fed into granulation silo 5 to obtain granules. These granules are then fed into a drying fluidized bed 6 for drying. The apparent velocity of the oxygen-deficient fluidizing gas is 1.0 m / s. Drying is carried out at 80°C for 60 minutes to obtain dried granules. The flue gas generated in the drying fluidized bed 6 is sent to a cyclone separator 7 and a cloth... The bag filter 8 collects dust, and the flue gas after dust removal is discharged through the induced draft fan 9. The collected dust is sent to the dust collection bin 10 and then returned to the high-speed shear granulator 4. The dried granulated material is sent to the three-stage cyclone preheater 11. The oxygen content in the preheating high-temperature gas is 5%. It is preheated to 600°C under the action of the hot flue gas generated in the flue gas combustion chamber 12, and then sent to the solidification bed 13. The solidification bed 13 adopts a bubbling fluidized bed. It relies on the high-temperature flue gas generated by combustion in the combustion heating chamber 14 to stay at 1000°C for 20 minutes. After solidification, it is sent to the cooler 15. The cooler adopts a bubbling fluidized bed. Air is introduced into the cooler 15. The apparent gas velocity of the mixed gas is 2m / s and the average residence time of the particles is 120 minutes. It exchanges heat with the high-temperature solidified material to obtain a heated mixed gas. The heated mixed gas is introduced into the combustion heating chamber 14, and fuel is introduced into the combustion heating chamber 14 to generate high-temperature flue gas. The cooled solidified material is ready for use. In this embodiment, high-speed shear granulation yielded a one-time yield of 82% for target particle sizes of 150–250 μm. The abrasion rate of the resulting consolidated material was 1.4%, and the average particle strength was 34.6 N / mm². 2 .

[0045] Example 3

[0046] This embodiment uses the system described in Example 1 to provide a method for efficient granulation modification of titanium-rich fine powder, including the following steps:

[0047] Titanium-rich material with a TiO2 content of 90.8%, a particle size of 25-50 μm, a CaO content of 0.24%, and a MgO content of 1.08%, and high-titanium slag with a TiO2 content of 95%, a particle size of 25-50 μm, a CaO content of 0.18%, and a MgO content of 0.96%, were fed into a high-speed shear granulator 4. Dextrin, metatitanic acid, and water were added. The mass ratio of the titanium-rich material powder, the high-titanium slag, the binder, and the water was 1:0.3:0.05:0.1. The rotor speed is 500 rpm, the disc speed is 50 rpm, and the granulation time is 5 min, obtaining particles with a diameter of 1000-2000 μm. The obtained moist granulated material is fed into the granulation silo 5 to obtain granules, which are then fed into the drying fluidized bed 6 for drying. The apparent gas velocity of the oxygen-deficient fluidizing gas is 2.0 m / s, and the material is dried at 100℃ for 40 min to obtain dried granules. The flue gas generated by the drying fluidized bed 6 is sent to the cyclone separator 7 and the bag filter 8 for further processing. The flue gas after dust removal is discharged through the induced draft fan 9, and the collected dust is sent to the dust collection bin 10 and then returned to the high-speed shear granulator 4. The dried granulated material is sent to the 5-stage cyclone preheater 11. The oxygen content in the preheating high-temperature gas is 5%. It is preheated to 800°C under the action of the hot flue gas generated in the flue gas combustion chamber 12, and then sent to the solidification bed 13. The solidification bed 13 adopts a bubbling fluidized bed. It relies on the high-temperature flue gas generated by combustion in the combustion heating chamber 14 to stay at 1100°C for 15 minutes. After solidification, it is sent to the cooler 15. The cooler adopts a bubbling fluidized bed. A mixed gas with a nitrogen / air volume flow ratio of 0.5 is introduced into the cooler 15. The apparent gas velocity of the mixed gas is 1 m / s and the average residence time of the particles is 45 minutes. It exchanges heat with the high-temperature solidified material to obtain a heated mixed gas. The heated mixed gas is introduced into the combustion heating chamber 14, and fuel is introduced into the combustion heating chamber 14 to generate high-temperature flue gas. The cooled solidified material is then ready for use. In this embodiment, high-speed shear granulation achieved a one-time yield of 81% for target particle sizes of 1000–2000 μm, with a consolidated material abrasion rate of 1.8% and an average particle strength of 34.3 N / mm². 2 .

[0048] Example 4

[0049] This embodiment uses the system described in Example 1 to provide a method for efficient granulation modification of titanium-rich fine powder, including the following steps:

[0050] Titanium-rich material with a TiO2 content of 82.3% and a particle size of 25–50 μm, a CaO content of 0.44%, and a MgO content of 1.36%, and high-titanium slag with a TiO2 content of 85.6% and a particle size of 25–50 μm, a CaO content of 0.36%, and a MgO content of 1.27%, were fed into a high-speed shear granulator 4. Carboxymethyl cellulose, titanium oxalate, and water were added. The mass ratio of the titanium-rich fine powder, the high-titanium slag, the binder, and the water was 1:0.2:0.03:0.08. The granulator rotor speed is 300 rpm, the disc speed is 10 rpm, and the granulation time is 20 min, obtaining particles with a diameter of 500-1000 μm. The obtained moist granulated material is fed into the granulation silo 5 to obtain granules, and then the granules are fed into the drying fluidized bed 6 for drying. The apparent gas velocity of the oxygen-deficient fluidized gas is 0.8 m / s, and the drying is carried out at 180℃ for 10 min to obtain dried granules. The flue gas generated by the drying fluidized bed 6 is sent to the cyclone separator 7 and the bag filter dust collector 8. After dust removal, the flue gas is discharged through the induced draft fan 9, and the collected dust is sent to the dust collection bin 10 and then returned to the high-speed shear granulator 4. The dried granulated material is sent to the four-stage cyclone preheater 11, where the oxygen content in the preheating high-temperature gas is 0.8%. Under the action of the hot flue gas generated in the flue gas combustion chamber 12, it is preheated to 680°C and then sent to the solidified bed 13. The solidified bed 13 adopts a bubbling fluidized bed, relying on the high-temperature flue gas generated by combustion in the combustion heating chamber 14, and stays at 960°C for 3 minutes. After 0 min of consolidation, the material is fed into cooler 15, which is a bubbling fluidized bed cooler. A mixed gas with a nitrogen / air volume flow ratio of 0.2 is introduced into cooler 15, with an apparent gas velocity of 1.5 m / s and an average particle residence time of 60 min. The material is heated by heat exchange with the high-temperature consolidated material. The heated mixed gas is then introduced into combustion chamber 14, where fuel is burned to produce high-temperature flue gas. The cooled consolidated material is then ready for use. In this embodiment, high-speed shear granulation achieves a one-time yield of 86% for target particle sizes of 500–1000 μm, a consolidated material abrasion rate of 2.6%, and an average particle strength of 33.7 N / mm². 2 .

[0051] Example 5

[0052] This embodiment uses the system described in Example 1 to provide a method for efficient granulation modification of titanium-rich fine powder, including the following steps:

[0053] Titanium-rich material with a TiO2 content of 92.1% (particle size 5–50 μm), CaO content of 0.12%, and MgO content of 0.95%, and high-titanium slag with a TiO2 content of 82.7% (particle size 5–100 μm), CaO content of 0.42%, and MgO content of 1.28%, were fed into a high-speed shear granulator 4. Ferrous alginate and water were added. The mass ratio of the titanium-rich fine powder, high-titanium slag, binder, and water was 1:0.3:0.04:0.1. The granulator rotated... The rotor speed is 100 rpm, the disc speed is 100 rpm, and the granulation time is 60 min, resulting in particles with a diameter of 400-500 μm. The obtained moist granulated material is fed into the granulation silo 5 to obtain granules, which are then fed into the drying fluidized bed 6 for drying. The apparent gas velocity of the oxygen-deficient fluidizing gas is 1.2 m / s, and the material is dried at 150℃ for 25 min to obtain dried granules. The flue gas generated by the drying fluidized bed 6 is sent to the cyclone separator 7 and the bag filter 8 for further processing. The flue gas after dust removal is discharged through the induced draft fan 9, and the collected dust is sent to the dust collection bin 10 and then returned to the high-speed shear granulator 4. The dried granulated material is sent to the 6-stage cyclone preheater 11, where the oxygen content of the preheating high-temperature gas is 1.2%. Under the action of the hot flue gas generated in the flue gas combustion chamber 12, it is preheated to 600°C and then sent to the solidified bed 13. The solidified bed 13 adopts a bubbling fluidized bed, relying on the high-temperature flue gas generated by combustion in the combustion heating chamber 14, and is held at 900°C for 45 minutes. After consolidation, the particles are fed into cooler 15, which is a bubbling fluidized bed cooler. A mixed gas with a nitrogen / air volume flow rate ratio of 0.5 is introduced into cooler 15, with an apparent gas velocity of 0.8 m / s and an average particle residence time of 30 min. The particles are heated by heat exchange with the high-temperature consolidated material. The heated mixed gas is then introduced into combustion chamber 14, where fuel is burned to produce high-temperature flue gas. The cooled consolidated material is then ready for use. In this embodiment, high-speed shear granulation achieves a one-time yield of 80% for target particle sizes of 400–500 μm, a consolidated material abrasion rate of 2.4%, and an average particle strength of 33.8 N / mm². 2 .

[0054] Comparative Example 1

[0055] Using the system described in Example 1, polyethylene glycol was used instead of carboxymethyl cellulose in the same amount, and other parameters were the same as in Example 1. The yield of a single-pass yield of 26% was obtained with a target particle size of 500–1000 μm, an abrasion rate of 5.8%, and an average particle strength of 12.3 N / mm². 2 .

[0056] Comparative Example 2

[0057] Using the system described in Example 1, starch was used instead of dextrin in the same amount as in Example 3, and other parameters were the same. The first-pass yield of the product with a target particle size of 1000–2000 μm was 18%, the wear rate was 7.6%, and the average particle strength was 5.8 N / mm². 2 .

[0058] Comparative Example 3

[0059] Using the system described in Example 1, with dextrin as the binder and everything else the same as in Example 3, a one-time yield of 25.6% was obtained for target particle sizes of 1000–2000 μm, with an abrasion rate of 13.8% and an average particle strength of 2.4 N / mm. 2 .

[0060] Comparative Example 4

[0061] In the three-stage cyclone preheater 11, the high-temperature flue gas from the consolidated bed 13 is directly used without activating the flue gas combustion chamber 12 for combustion and oxygen consumption. All other conditions are exactly the same as in Example 2. In this example, the high-speed shear granulation yield is 76.4% in a single pass, the abrasion rate of the obtained consolidated material is 8.3%, and the average particle strength is 12.4 N / mm². 2 Because the oxygen content in the high-temperature solidification flue gas was not reduced or completely consumed, the strength of the solidified material was negatively affected. Furthermore, fuel consumption increased by 18% during the solidification process.

[0062] The above are merely specific embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-efficiency granulation modification system for titanium-rich fine powder, comprising a titanium-rich material silo, a high-titanium slag fine powder silo, and a binder silo, wherein the binder silo contains an organic titanium / iron binder, or a mixture of an organic titanium / iron binder and an organic binder, wherein the organic binder is one or two of dextrin and carboxymethyl cellulose, and the organic titanium / iron binder is at least one of titanium oxalate, ferrous oxalate, metatitanic acid, ferrous alginate, and ferrous alginate; The discharge ports of the titanium-rich material silo, the high-titanium slag fine powder silo, and the binder silo are connected to the inlet of the granulation equipment; the discharge port of the granulation equipment is connected to the inlet of the granulation silo; and the discharge port of the granulation silo is connected to the inlet of the drying equipment. Its characteristic is that: The granulation equipment is a high-speed shear granulator, and the drying equipment is a fluidized bed dryer. The air outlet of the drying equipment is connected to a cyclone dust collector. The discharge port of the cyclone dust collector is connected to a dust collection bin, and the air outlet of the cyclone dust collector is connected to a bag filter dust collector. The air outlet of the bag filter dust collector is connected to an induced draft fan, and the air outlet of the induced draft fan is connected to a vent pipe. The discharge port of the bag filter dust collector is connected to the inlet of the dust collection bin. The air inlet of the drying equipment is connected to the outlet of the cyclone preheater, and the inlet of the cyclone preheater is connected to the drying... The equipment discharge port and the flue gas combustion chamber outlet are connected; the cyclone preheater discharge port is connected to the solidified bed feed port; the flue gas combustion chamber inlet is connected to the solidified bed outlet and the fuel pipeline; the solidified bed discharge port is connected to the cooler feed port, and the solidified bed inlet is connected to the combustion heating chamber outlet; the combustion heating chamber inlet is connected to the fuel pipeline and the cooler outlet; the cooler inlet is connected to an air pipeline and a nitrogen pipeline, and the cooler discharge port is connected to a discharge pipeline.

2. The high-efficiency granulation modification system for titanium-rich fine powder according to claim 1, characterized in that: The dust collection bin outlet is connected to the feed inlet of the high-speed shear granulator.

3. The high-efficiency granulation modification system for titanium-rich fine powder according to claim 1, characterized in that: The inlet of the high-speed shear granulator is connected to a process water pipeline.

4. The high-efficiency granulation modification system for titanium-rich fine powder according to claim 1, characterized in that: The cyclone preheater is multi-stage, with the lower outlet of the higher-stage cyclone connected to the inlet of the lower-stage cyclone, and the top outlet of the lower-stage cyclone connected to the inlet of the higher-stage cyclone.

5. A method for efficient granulation modification of titanium-rich fine powder using the system described in claim 1, characterized in that: Includes the following steps: (1) The titanium-rich material, high-titanium slag fine powder and binder are fed into a high-speed shear granulator and water is added. Under the action of the high-speed shear granulator, granules with a particle size of 0.15-2 mm are obtained. The rotor speed of the granulator is 100-3000 rpm, the disc speed is 10-200 rpm, and the granulation time is 5-60 min. The binder is an organic titanium / iron binder or a mixture of organic titanium / iron binder and organic binder. The organic binder is one or two of dextrin and carboxymethyl cellulose. The organic titanium / iron binder is at least one of titanium oxalate, ferrous oxalate, metatitanic acid, ferric alginate, and ferrous alginate. The mass ratio of titanium-rich material fine powder, high-titanium slag fine powder, binder and water is 1:0.1-0.3:0.005-0.05:0.05-0.

1. (2) The granulated material is fed into the drying fluidized bed, and the flue gas from the multi-stage cyclone preheater is introduced into the drying fluidized bed to dry the granulated material; (3) The dried granulated material is fed into a multi-stage cyclone preheater; the flue gas generated by the drying fluidized bed is fed into a cyclone separator and a bag filter. The flue gas after dust removal is discharged by an induced draft fan. The collected dust is sent into a dust collection bin and then returned to the high-speed shear granulator. The granulated material is fed into a multi-stage cyclone preheater after drying. It is preheated by exchanging heat with the flue gas generated by the flue gas combustion chamber. Fuel is introduced into the flue gas combustion chamber, and hot flue gas from the solidified bed is introduced to consume the oxygen in the hot flue gas by the combustion of the fuel. The preheated granulated material is fed into the solidified bed. The high-temperature flue gas generated by the combustion in the combustion heating chamber causes the granulated material to solidify in the solidified bed. After solidification, it is sent into a cooler. A mixture of air and nitrogen is introduced into the cooler to exchange heat with the high-temperature solidified material and heat it. The heated mixture is introduced into the combustion heating chamber, and fuel is introduced to burn in the combustion heating chamber to generate high-temperature flue gas which is then sent into the solidified bed. After cooling, the solidified material is obtained.

6. The method for efficient granulation modification of titanium-rich fine powder according to claim 5, characterized in that, The titanium-rich material has a TiO2 content of 70%–98%, an average particle size of 5–100 μm, a CaO content of 0–0.5%, and a MgO content of 0%–1.5%; the high-titanium slag has a TiO2 content of 70%–95%, an average particle size of 5–100 μm, a CaO content of 0–0.5%, and a MgO content of 0%–1.5%.

7. The method for efficient granulation modification of titanium-rich fine powder according to claim 5, characterized in that, The temperature in the drying fluidized bed is 80–200℃, the apparent gas velocity is 0.5–2.0 m / s, and the average particle residence time is 5–60 min.

8. The method for efficient granulation modification of titanium-rich fine powder according to claim 5, characterized in that, The multi-stage cyclone preheater has 2 to 6 stages, and the oxygen content of the preheated high-temperature gas after combustion deoxygenation is 0% to 5%.

9. The method for efficient granulation modification of titanium-rich fine powder according to claim 5, characterized in that, The consolidated bed is a bubbling fluidized bed or a circulating fluidized bed, and the temperature in the consolidated bed is 800-1100℃, with an average particle residence time of 15-60 min.

10. The method for efficient granulation modification of titanium-rich fine powder according to claim 5, characterized in that, The cooler adopts a bubbling fluidized bed with a gas apparent velocity of 0.5 to 2.0 m / s and an average particle residence time of 30 to 120 min. The nitrogen / air volume flow rate ratio of the mixed air and nitrogen gas is (0 to 1): 1.

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