Ilmenite low-temperature fluidization magnetizing roasting system and ilmenite low-temperature fluidization magnetizing roasting method

Abstract

The invention relates to the field of pretreatment and quality improvement of ores by adopting a roasting process, in particular to an ilmenite low-temperature fluidization magnetizing roasting system and method, and the system comprises a feeding bin, a dryer, a cyclone preheater, a fluidization roasting furnace, a cyclone cooler and a discharging bin. The method comprises the following steps: dehydrating mineral powder from a feeding bin through a dryer; preheating the dried ore by a cyclone preheater; carrying out low-temperature fluidization oxidation magnetization roasting on the hot mineral powder; and the hot roasted ore is cooled by an air cyclone cooler and then is magnetically separated. The method has the advantages of low-temperature oxidation of the ilmenite, adjustable oxidation degree, efficient utilization of sensible heat of roasted ore and low energy consumption of the system, and can realize the efficient separation and utilization target of upgrading and impurity removal of the ilmenite.

Description

Technical Field

[0001] The present invention belongs to the field of mineral processing and metallurgical joint process, and is used for pretreatment and quality improvement of ilmenite raw material minerals for the production of ilmenite-iron symbiotic metal element products, and particularly relates to pretreatment and quality improvement of ore by using a roasting process, and specifically relates to a low-temperature fluidized magnetization roasting system and method for ilmenite. Background Art

[0002] Titanium is an important metal resource for the development of the national economy. Titanium is mainly found in ilmenite and rutile. my country is rich in titanium resources, accounting for about 24% of the world's total reserves, of which 98% is ilmenite. However, my country's primary ilmenite resources are poor, fine, and mixed. With the depth of mining, the useful titanium-containing components in the ore are becoming less and less. The separation of low-grade ilmenite using conventional magnetic separation, gravity separation, flotation and other processes is becoming more and more difficult, and the recovery rate is low. Therefore, the development of new low-cost and high-efficiency industrial ilmenite separation and utilization methods is of great significance to improving the development and utilization of my country's ilmenite resources, promoting the development of downstream titanium-iron symbiotic metal element smelting production and other related industries, and the innovation and upgrading of the pre-treatment technology of the raw materials in the titanium industry throughout the entire process.

[0003] Primary ilmenite (FeTiO 3 ) is a weakly magnetic mineral. It is oxidized and roasted (FeTiO 3 +O 2 →Fe 2 O 3 +TiO 2 ) is converted into ilmenite-hematite solid solution [xFeTiO 3 ·(1-x)Fe 2 O 3 ] can significantly improve its ferromagnetism, and then use conventional magnetic separation process to separate the oxidized modified ilmenite from weakly magnetic impurities such as calcium, magnesium, aluminum, silicon, chromium, etc., so as to achieve effective beneficiation and enrichment of low-grade ilmenite and impurity removal and quality improvement. The oxidation magnetization roasting-magnetic separation process is considered to be one of the most effective industrial solutions to replace the existing conventional beneficiation process to achieve efficient enrichment and quality improvement of ilmenite resources. For example, Chinese patents CN 1037983C, CN 1225562C, CN 103316761B, CN 103736585A, CN 114084902B, and CN117737407A all mention the ilmenite oxidation magnetization roasting process in the principle process flow of ilmenite resource utilization and beneficiation.

[0004] At present, there are three main types of equipment for mineral roasting: vertical furnace, rotary kiln, and fluidized bed. Among them, vertical furnaces and rotary kilns require the raw material particle size to be above the centimeter level, which is difficult to adapt to the current ilmenite mining and grinding fine particle size, basically in the state of powder ore particles at the millimeter level or below, and due to the large particle size of the charge and poor reaction kinetics, its energy consumption is high. The fluidized bed adopts a fluidized roasting reaction mode, which can directly feed millimeter-level or below powder materials. It has the outstanding advantages of high low-temperature reaction efficiency, low energy consumption, and uniform phase transition of reactants. Therefore, it is the main direction of current mineral roasting industrial applications. However, the existing industrial solutions for fluidized roasting of ilmenite are mostly based on the principle of production process layout at the level of the whole process of grinding, roasting, magnetic separation, etc., and there are few designs for fluidized oxidation magnetization roasting systems and methods for ilmenite. Chinese patent CN 106861892A designs a separation device containing chromite and ilmenite ores. The device includes a roasting system arrangement including a roasting furnace, a cyclone, and a fluidized bed cooler. However, the temperature of the hot ilmenite roasted ore is sent out of the roasting system in the form of hot water through a heat exchange component. This part of the heat cannot be used in the roasting system, and the system energy consumption can be further reduced. At the same time, the patent has an oxidation roasting time of 30-180 seconds. The ilmenite (FeTiO 3 ) to ilmenite-hematite solid solution [xFeTiO 3 ·(1-x)Fe 2 O 3 ] is not a very fast reaction process, and due to the complexity of natural minerals, a wider operating range is required to ensure that ilmenite FeTiO 3 Medium ferrous iron Fe 2+ Fe 3+ Full and appropriate proportion conversion.

[0005] Therefore, there is a need in the art for a high-efficiency, low-consumption, low-temperature fluidized magnetized roasting system and method for ilmenite based on the principle advantages of a fluidized bed reactor and targeting the oxidation roasting reaction characteristics of ilmenite. Summary of the invention

[0006] The purpose of the present invention is to provide a low-temperature fluidized magnetized roasting system and method for ilmenite, which can realize efficient oxidation regulation of low-grade ilmenite through the low-temperature fluidized oxidation magnetized roasting system, and optimize the energy migration utilization in the system, so as to ultimately achieve efficient and low-consumption comprehensive utilization of low-grade ilmenite resources.

[0007] The present invention provides a low-temperature fluidized magnetized roasting system for ilmenite, comprising a feed bin, a dryer, a cyclone preheater, a fluidized roasting furnace, a cyclone cooler, and a discharge bin; The dryer includes a supplementary heat burner 13, a venturi airflow dryer 2, a drying cyclone separator 3 and a bag dust collector 4; the cyclone preheater includes a multi-stage preheating cyclone and a preheating burner 12; the fluidized bed roasting furnace includes a roasting furnace body 7 and a roasting cyclone separator 8; the cyclone cooler includes a multi-stage air cooling cyclone; wherein, The discharge port of the feed bin 1 is connected to the feed port of the venturi airflow dryer 2, the top air outlet of the venturi airflow dryer 2 is connected to the air inlet of the drying cyclone separator 3, the top air outlet of the drying cyclone separator 3 is connected to the air inlet of the bag dust collector 4, the lower discharge port of the drying cyclone separator 3 and the lower return port of the bag dust collector 4 are both connected to the air inlet of the highest level preheating cyclone, the air inlet of the supplementary heat burner 13 is respectively connected to the fuel pipeline and the top air outlet of the highest level preheating cyclone, and the air outlet of the supplementary heat burner 13 is connected to the bottom air inlet of the venturi airflow dryer 2; The air inlet of the highest level preheating cyclone is connected to the lower discharge port of the drying cyclone separator 3 and the lower return port of the bag dust collector 4 at the same time, the top air outlet of the highest level preheating cyclone is connected to the air inlet of the supplementary heat burner 13, the air inlet of the lowest level preheating cyclone in the multi-stage preheating cyclone and the lower discharge port of the highest level preheating cyclone are connected to the top air outlet of the preheating burner 12, the air inlet of the preheating burner 12 is respectively connected to the fuel pipeline and the top air outlet of the roasting cyclone separator 8, and the lower discharge port of the lowest level preheating cyclone is connected to the feed port of the roasting furnace body 7; The feed inlet of the roasting furnace body 7 is connected to the lower discharge port of the lowest level preheating cyclone, the top air outlet of the roasting furnace body 7 is connected to the air inlet of the roasting cyclone separator 8, the top air outlet of the roasting cyclone separator 8 is connected to the air inlet of the preheating burner 12, the bottom discharge port of the roasting cyclone separator 8 is connected to the return port of the roasting furnace body 7, the bottom air inlet of the roasting furnace body 7 is connected to the top air outlet of the highest level air cooling cyclone, and the discharge port of the roasting furnace body 7 is connected to the air inlet of the highest level air cooling cyclone; The air inlet of the highest level air cooling cyclone is connected to the discharge port of the roasting furnace body 7, the air outlet of the highest level air cooling cyclone is connected to the bottom air inlet of the roasting furnace body 7, the air inlet of the lowest level air cooling cyclone and the bottom discharge port of the highest level air cooling cyclone are connected to the air supply pipeline, and the bottom discharge port of the lowest level air cooling cyclone is connected to the feed port of the discharge bin 11.

[0008] Preferably, the cyclone preheater comprises multiple stages of preheating cyclones, and the preheating cyclones at each stage are sequentially connected in series; In the multi-stage preheating cyclone, when the number of stages is two, the lower discharge port of the first-stage preheating cyclone 5 is connected to the air inlet of the second-stage preheating cyclone 6, and the top air outlet of the second-stage preheating cyclone 6 is connected to the air inlet of the first-stage preheating cyclone 5; When the number of stages is two or more, the air inlet of the highest stage preheating cyclone is simultaneously connected to the lower discharge port of the drying cyclone separator 3 and the lower return port of the bag dust collector 4; The top air outlet of the highest level preheating cyclone is connected to the air inlet of the supplementary heat burner 13; The air inlet of the lowest level preheating cyclone is connected to the top air outlet of the preheating burner 12; The lower discharge port of the lowest level preheating cyclone is connected to the feed port of the roasting furnace body 7; The lower discharge port of the higher-level preheating cyclone is connected to the air inlet of the lower-level preheating cyclone, and the top air outlet of the lower-level preheating cyclone is connected to the air inlet of the higher-level preheating cyclone.

[0009] It should be noted that in a multi-stage preheating cyclone, when there are two stages, the highest level preheating cyclone is the first level preheating cyclone, and the lowest level preheating cyclone is the second level preheating cyclone; when there are more than two stages, the highest level preheating cyclone is the first level preheating cyclone, for example, the first level is a higher level preheating cyclone than the second level, and the second level is a lower level preheating cyclone than the first level. It is further explained that the level in the multi-stage preheating cyclone generally refers to the height of the position where the preheating cyclone is set, for example, the setting position of the first level preheating cyclone is higher than the setting position of the second level preheating cyclone, the highest level preheating cyclone is the preheating cyclone with the highest position in the multi-stage preheating cyclone, and the lowest level preheating cyclone is the preheating cyclone with the lowest setting position.

[0010] Preferably, the bottom discharge port of the roasting cyclone separator 8 and the discharge port of the roasting furnace body 7 are located on different sides, and the roasting furnace is a turbulent fluidized bed.

[0011] Preferably, the air cooler comprises multiple stages of air cooling cyclones, and the air cooling cyclones at each stage are sequentially connected in series; In the multi-stage air cooling cyclone, when the number of stages is two, the lower discharge port of the first-stage air cooling cyclone 9 is connected to the air inlet of the second-stage air cooling cyclone 10, and the top air outlet of the second-stage air cooling cyclone 10 is connected to the air inlet of the first-stage air cooling cyclone 9; When the number of stages is two or more, the air inlet of the highest stage air cooling cyclone is connected to the discharge port of the roasting furnace body 7; The air outlet of the highest level air cooling cyclone is connected to the bottom air inlet of the roasting furnace body 7; The air inlet of the lowest-stage air cooling cyclone is connected to the air supply pipeline; The bottom discharge port of the lowest-level air cooling cyclone is connected to the feed port of the discharge bin 11 .

[0012] The lower discharge port of the higher-level air cooling cyclone is connected to the air inlet of the lower-level air cooling cyclone, and the top air outlet of the lower-level air cooling cyclone is connected to the air inlet of the higher-level air cooling cyclone.

[0013] It should be noted that in a multi-stage air cooling cyclone, when there are two stages, the highest level of air cooling cyclone is the first level air cooling cyclone, and the lowest level of air cooling cyclone is the second level air cooling cyclone; when there are more than two stages, the highest level of air cooling cyclone is the first level air cooling cyclone, for example, the first level is a higher level of air cooling cyclone than the second level, and the second level is a lower level of air cooling cyclone than the first level. It is further explained that the level in the multi-stage air cooling cyclone generally refers to the height of the position where the air cooling cyclone is set, for example, the setting position of the first level air cooling cyclone is higher than the setting position of the second level air cooling cyclone, the highest level of air cooling cyclone is the air cooling cyclone with the highest position in the multi-stage air cooling cyclone, and the lowest level of air cooling cyclone is the air cooling cyclone with the lowest setting position.

[0014] The present invention also provides a low-temperature fluidized magnetization roasting method for ilmenite based on the above system, the method comprising: The ilmenite powder stored in the feed bin enters the Venturi airflow dryer and is dehydrated and dried by the hot flue gas, and then is separated from the gas and solid by the drying cyclone separator. The dried ore powder after gas-solid separation and the dried ore powder collected by the bag dust collector enter the cyclone preheater together. In the multi-stage preheating cyclone, the ore powder and the hot flue gas after the hot tail gas of the fluidized bed roasting furnace are subjected to gas-solid countercurrent heat exchange and temperature rise. The heated hot ore powder enters the roasting furnace body and undergoes oxidation magnetization roasting reaction of ilmenite with the hot air. The roasted ore powder entrained by the airflow is separated from the gas and solid by the roasting cyclone separator and then returns to the roasting furnace body. The roasted ore powder enters the highest level air cooling cyclone from the discharge port of the roasting furnace body. In the air cooling cyclone, the hot roasted ore powder and the room temperature air are subjected to gas-solid countercurrent heat exchange and temperature reduction, and finally enters the discharge bin for storage; Room temperature air enters from the lowest level air cooling cyclone for gas-solid countercurrent heat exchange with the hot roasting powder. The hot air after heat exchange is discharged from the top outlet of the highest level air cooling cyclone into the roasting furnace body for oxidative magnetization roasting with ilmenite powder. The hot exhaust gas after the reaction is separated from the gas and solid by the roasting cyclone separator and enters the preheating burner. After heating with the fuel, it enters the cyclone preheater for gas-solid countercurrent heat exchange with the dry ore powder. The exhaust gas after heat exchange enters the supplementary heat burner and heats with the fuel, and then passes through the Venturi airflow dryer to dry the ilmenite powder, and then passes through the drying cyclone separator and bag dust collector for separation and purification before being discharged.

[0015] Preferably, the particle size of the ilmenite powder is in the range of 0.005-9 mm, and the TiO 2The content range is 10-47wt%, the water content is less than 15wt%, and the titanium and iron elements are mainly in the form of ilmenite phase FeTiO 3 exist.

[0016] Preferably, the temperature of the oxidative magnetization roasting reaction is 400-800°C, such as 400°C, 450°C, 500°C, 550°C, 600°C, 650°C, 700°C, 750°C, 800°C and the range between any two of the above data; the time of the oxidative magnetization roasting reaction is 5-180 minutes, such as 5 minutes, 15 minutes, 25 minutes, 35 minutes, 45 minutes, 65 minutes, 85 minutes, 95 minutes, 125 minutes, 145 minutes, 155 minutes, 165 minutes, 175 minutes, 180 minutes and the range between any two of the above data.

[0017] Preferably, after the ilmenite powder is oxidized and roasted in a fluidized bed, the ilmenite phase FeTiO 3 Iron (Fe) 2+ Fe 3+ The conversion ratio ranges from 10-90%, such as 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% and ranges between any two of the above data. The "%" here has no unit.

[0018] Preferably, the fuel is one or at least two of fuel oil, coal, fuel gas, and coal gas having combustion calorific value.

[0019] Preferably, the temperature of the air outlet of the drying cyclone separator is not less than 100°C, the final cooling temperature of the roasted ore powder entering the discharge bin is less than 100°C, and the temperature of the air entering the lowest level air cooling cyclone is not higher than 100°C.

[0020] Compared with the existing ilmenite oxidation magnetization roasting system and method, the characteristics and advantages of the present invention are: (1) Low-temperature oxidation magnetization roasting is carried out in the temperature range of 400-800℃ to avoid oxidation of ilmenite above 800℃ to generate weakly magnetic Fe 2 TiO 5 (Fe 2 O 3 TiO 2 ) The problem of reducing the magnetic properties of the titanium-containing phase and reducing the yield of the subsequent magnetic separation magnetic titanium-containing phase product; (2) The reaction residence time of the non-fast conveying bed is adjustable, and the turbulent fluidized bed and the cyclone separation of the oxidation tail gas of the roasting furnace are used to return the material, which ensures that the coarse-grained ilmenite particles have sufficient residence time in the furnace for slow oxidation reaction and the fluidized gas to quickly carry out the fine-grained ilmenite particles, resulting in a high magnetic phase conversion rate and strong adaptability to incoming materials; (3) Multi-stage cyclone air is used to cool the hot roasted ore and preheat the oxidation raw gas at the same time. The hot oxidation exhaust gas of the roasting furnace is burned to preheat the cold ore. A Venturi air flow dryer and a preheating burner are arranged to achieve the cooling-preheating-drying migration utilization of energy within the system. By adjusting the fuel supplement, a good heat-temperature balance can be achieved to optimize and reduce energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the system configuration of the low-temperature fluidized magnetized roasting of ilmenite according to the present invention.

[0022] Reference numerals: 1. Feed bin; 2. Venturi airflow dryer; 3. Drying cyclone separator; 4. Bag dust collector; 5. Primary preheating cyclone; 6. Secondary preheating cyclone; 7. Roasting furnace body; 8. Roasting cyclone separator; 9. Primary air cooling cyclone; 10. Secondary air cooling cyclone; 11. Discharge bin; 12. Preheating burner; 13. Supplementary heat burner. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with specific embodiments.

[0024] Example 1

[0025] like Figure 1 As shown, a low-temperature fluidized magnetized roasting system for ilmenite includes a feed bin, a dryer, a cyclone preheater, a fluidized roasting furnace, a cyclone cooler, and a discharge bin; The dryer includes a supplementary heat burner 13, a venturi airflow dryer 2, a drying cyclone separator 3 and a bag dust collector 4; the cyclone preheater includes a two-stage preheating cyclone and a preheating burner 12; the fluidized bed roasting furnace includes a roasting furnace body 7 and a roasting cyclone separator 8; the cyclone cooler includes a two-stage air cooling cyclone; wherein, The discharge port of the feed bin 1 is connected to the feed port of the venturi airflow dryer 2, the top air outlet of the venturi airflow dryer 2 is connected to the air inlet of the drying cyclone separator 3, the top air outlet of the drying cyclone separator 3 is connected to the air inlet of the bag dust collector 4, the lower discharge port of the drying cyclone separator 3 and the lower return port of the bag dust collector 4 are both connected to the air inlet of the primary preheating cyclone 5, the air inlet of the supplementary heat burner 13 is respectively connected to the fuel pipeline and the top air outlet of the primary preheating cyclone 5, and the air outlet of the supplementary heat burner 13 is connected to the bottom air inlet of the venturi airflow dryer 2; The air inlet of the first-stage preheating cyclone 5 is connected to the lower discharge port of the drying cyclone separator 3 and the lower return port of the bag dust collector 4 at the same time, the top air outlet of the first-stage preheating cyclone 5 is connected to the air inlet of the supplementary heat burner 13, the air inlet of the second-stage preheating cyclone 6 is connected to the top air outlet of the preheating burner 12, the air inlet of the preheating burner 12 is respectively connected to the fuel pipeline and the top air outlet of the roasting cyclone separator 8, and the lower discharge port of the second-stage preheating cyclone 6 is connected to the feed port of the roasting furnace body 7; The feed inlet of the roasting furnace body 7 is connected to the lower discharge port of the secondary preheating cyclone 6, the top air outlet of the roasting furnace body 7 is connected to the air inlet of the roasting cyclone separator 8, the top air outlet of the roasting cyclone separator 8 is connected to the air inlet of the preheating burner 12, the bottom discharge port of the roasting cyclone separator 8 is connected to the return port of the roasting furnace body 7, the bottom air inlet of the roasting furnace body 7 is connected to the top air outlet of the primary air cooling cyclone 9, and the discharge port of the roasting furnace body 7 is connected to the air inlet of the primary air cooling cyclone 9; The air inlet of the primary air cooling cyclone 9 is connected to the discharge port of the roasting furnace body 7, the air outlet of the primary air cooling cyclone 9 is connected to the bottom air inlet of the roasting furnace body 7, the air inlet of the secondary air cooling cyclone 10 is connected to the air supply pipeline, and the bottom discharge port of the secondary air cooling cyclone 10 is connected to the feed port of the discharge bin 11.

[0026] The bottom discharge port of the roasting cyclone separator 8 and the discharge port of the roasting furnace body 7 are located on different sides, that is, the bottom discharge port of the roasting cyclone separator 8 is not directly connected to the discharge port of the roasting furnace body 7, and the roasting furnace is a turbulent fluidized bed.

[0027] To further explain, if the shape of the roasting furnace body 7 is a cube, the bottom discharge port of the roasting cyclone separator 8 and the discharge port of the roasting furnace body 7 are located on different sides; if the shape of the roasting furnace body 7 is a cylinder, the bottom discharge port of the roasting cyclone separator 8 and the discharge port of the roasting furnace body 7 are located on the outer side of the cylinder, and the center angle between the bottom discharge port of the roasting cyclone separator 8 and the discharge port of the roasting furnace body 7 is greater than 45 degrees.

[0028] In this embodiment, the number of preheating cyclones and air cooling cyclones can be changed as needed, and the structure listed here is only a better implementation of the present invention.

[0029] Example 2

[0030] The method for fluidized oxidation magnetization roasting of ilmenite using the above-mentioned ilmenite low-temperature fluidized roasting system is as follows: The ilmenite powder is stored in the feed bin and enters the Venturi airflow dryer to be dehydrated and dried by hot flue gas, and then separated from the gas and solid by the drying cyclone separator. The dried ore powder after gas-solid separation and the dried ore powder collected by the bag dust collector enter the cyclone preheater together. In the multi-stage preheating cyclone, the ore powder and the hot flue gas after the hot tail gas of the fluidized bed roaster are subjected to gas-solid countercurrent heat exchange and temperature rise. The heated hot ore powder enters the roasting furnace body and undergoes oxidation magnetization roasting reaction of ilmenite with hot air. The roasted ore powder entrained by the air flow is separated from the gas and solid by the roasting cyclone separator and then returns to the roasting furnace body. The roasted ore powder enters the highest level air cooling cyclone from the discharge port of the roasting furnace body. In the air cooling cyclone, the hot roasted ore powder and the room temperature air are subjected to gas-solid countercurrent heat exchange and temperature reduction, and finally enters the discharge bin for storage; Room temperature air enters from the lowest level air cooling cyclone for gas-solid countercurrent heat exchange with the hot roasting powder. The hot air after heat exchange is discharged from the top outlet of the highest level air cooling cyclone into the roasting furnace body for oxidative magnetization roasting with ilmenite powder. The hot exhaust gas after the reaction is separated from the gas and solid by the roasting cyclone separator and enters the preheating burner. After heating with the fuel, it enters the cyclone preheater for gas-solid countercurrent heat exchange with the dry ore powder. The exhaust gas after heat exchange enters the supplementary heat burner and heats up with the fuel. After that, it passes through the Venturi airflow dryer to dry the ilmenite powder, and then passes through the drying cyclone separator and bag dust collector for separation and purification before being discharged.

[0031] Example 3

[0032] The present invention is used to treat titanium grade TiO 2 The content is 36 wt %, the particle size is 0.03-1 mm, of which the particle size less than 0.074 mm accounts for 30%. The titanium and iron elements in the ore powder are ilmenite phase FeTiO 3 Present, free water content 10 wt %.

[0033] First, the ilmenite powder is sent from the feed bin to the Venturi airflow dryer to be dehydrated and dried by hot flue gas. The temperature of the hot flue gas exhaust after drying is 110℃, and the free water content of the powder after dehydration is <1 wt%. The powder is then heated by heat exchange with the exhaust gas of the fluidized bed after combustion in the three-stage cyclone preheater, and then enters the turbulent fluidized bed for oxidative magnetization roasting at 750℃ with the preheated air for 40 minutes. The ilmenite phase FeTiO 3 Iron (Fe) 2+ Fe 3+ The conversion ratio is 37%. The hot roasted ore is directly cooled to 80℃ by the three-stage air cooling cyclone and enters the discharge ore bin. The cooling medium is room temperature air. The air after the three-stage air cooling cyclone and the hot roasted ore is sent into the roasting fluidized bed as the oxidizing gas to react with the ilmenite powder. The fuels of the preheating burner and the supplementary heat burner are natural gas, methane CH 4 The volume content is 92%.

[0034] After the cooling roasted ore is ground and separated into mineral phases, the titanium grade TiO can be separated by 3500 Oe weak magnetic separation. 2 The titanium concentrate powder product has a content of 47.5wt% and a titanium element yield of 90.2%, which is a good indicator.

[0035] Example 4

[0036] The present invention is used to treat titanium grade TiO 2 The content is 26 wt %, and the particle size is 0.15-2.5 mm, of which the particle size is less than 1 mm, accounting for 60%. The titanium and iron elements in the ore powder are ilmenite phase FeTiO 3 Present, free water content 8 wt %.

[0037] First, the ilmenite powder is sent from the feed bin to the Venturi airflow dryer to be dehydrated and dried by hot flue gas. The temperature of the hot flue gas exhaust after drying is 105℃, and the free water content of the powder after dehydration is <1 wt%. The powder is then heated by heat exchange with the exhaust gas of the fluidized bed after combustion in a two-stage cyclone preheater, and then enters the turbulent fluidized bed for oxidative magnetization roasting at 650℃ with preheated air for 100 minutes. The ilmenite phase FeTiO 3 Iron (Fe) 2+ Fe 3+ The conversion ratio is 30%. The hot roasted ore is directly cooled to 87℃ by the three-stage air cooling cyclone and enters the discharge ore bin. The cooling medium is room temperature air. The air after heat exchange with the hot roasted ore by the three-stage air cooling cyclone is sent into the roasting fluidized bed as oxidizing gas to react with the ilmenite powder. The fuel for the preheating burner and the supplementary heat burner is pulverized coal, and the calorific value of pulverized coal is 4800 kcal / kg.

[0038] After the cooling roasted ore is ground and separated into mineral phases, 4000 Oe weak magnetic separation can be used to separate titanium grade TiO 2 The titanium concentrate powder product has a titanium content of 48.0 wt %, and a titanium yield of 91.0%, which is a good indicator.

[0039] The process parameters (such as temperature, time, etc.) of the present invention can realize the method by taking upper and lower limits and interval values, and the embodiments are not listed one by one here.

[0040] Any contents not described in detail in the present invention can be based on the conventional technical knowledge in the art.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention is described in detail with reference to the embodiments, it should be understood by those skilled in the art that any modification or equivalent replacement of the technical solutions of the present invention does not depart from the spirit and scope of the technical solutions of the present invention and should be included in the scope of the claims of the present invention.

Claims

1. A low-temperature fluidized magnetized roasting system for ilmenite, Features: The system includes a feed bin, a dryer, a cyclone preheater, a fluidized bed roaster, a cyclone cooler, and a discharge bin; The dryer comprises a supplementary heat burner (13), a Venturi airflow dryer (2), a drying cyclone separator (3) and a bag dust collector (4); the cyclone preheater comprises a multi-stage preheating cyclone and a preheating burner (12); the fluidized bed roasting furnace comprises a roasting furnace body (7) and a roasting cyclone separator (8); the cyclone cooler comprises a multi-stage air cooling cyclone; wherein, The discharge port of the feed bin (1) is connected to the feed port of the venturi airflow dryer (2), the top air outlet of the venturi airflow dryer (2) is connected to the air inlet of the drying cyclone separator (3), the top air outlet of the drying cyclone separator (3) is connected to the air inlet of the bag dust collector (4), the lower discharge port of the drying cyclone separator (3) and the lower return port of the bag dust collector (4) are both connected to the air inlet of the highest level preheating cyclone, the air inlet of the supplementary heat burner (13) is respectively connected to the fuel pipeline and the top air outlet of the highest level preheating cyclone, and the air outlet of the supplementary heat burner (13) is connected to the bottom air inlet of the venturi airflow dryer (2); The air inlet of the lowest preheating cyclone in the multi-stage preheating cyclone and the lower discharge port of the highest preheating cyclone are connected to the top air outlet of the preheating burner (12), the air inlet of the preheating burner (12) is respectively connected to the fuel pipeline and the top air outlet of the roasting cyclone separator (8), and the lower discharge port of the lowest preheating cyclone is connected to the feed port of the roasting furnace body (7); The top air outlet of the roasting furnace body (7) is connected to the air inlet of the roasting cyclone separator (8), the bottom discharge port of the roasting cyclone separator (8) is connected to the return port of the roasting furnace body (7), the bottom air inlet of the roasting furnace body (7) is connected to the top air outlet of the highest level air cooling cyclone, and the discharge port of the roasting furnace body (7) is connected to the air inlet of the highest level air cooling cyclone; The air inlet of the lowest level air cooling cyclone and the bottom outlet of the highest level air cooling cyclone are connected to the air supply pipeline, and the bottom outlet of the lowest level air cooling cyclone is connected to the feed inlet of the outlet bin (11).

2. The ilmenite low temperature fluidized magnetization roasting system according to claim 1, Features: The cyclone preheater comprises multiple stages of preheating cyclones, and the preheating cyclones at each stage are sequentially connected in series; When the number of stages is two, the lower outlet of the first-stage preheating cyclone (5) is connected to the air inlet of the second-stage preheating cyclone (6), and the top outlet of the second-stage preheating cyclone (6) is connected to the air inlet of the first-stage preheating cyclone (5); When the number of stages is two or more, the lower discharge port of the higher-level preheating cyclone is connected to the air inlet of the lower-level preheating cyclone, and the top air outlet of the lower-level preheating cyclone is connected to the air inlet of the higher-level preheating cyclone.

3. The ilmenite low temperature fluidized magnetization roasting system according to claim 1, Features: The bottom discharge port of the roasting cyclone separator (8) and the discharge port of the roasting furnace body (7) are located on different sides, and the roasting furnace body is a turbulent fluidized bed.

4. The ilmenite low temperature fluidized magnetization roasting system according to claim 1, Features: The air cooler comprises multiple stages of air cooling cyclones, and the air cooling cyclones at each stage are sequentially connected in series; When the number of stages is two, the lower outlet of the first-stage air cooling cyclone (9) is connected to the air inlet of the second-stage air cooling cyclone (10), and the top outlet of the second-stage air cooling cyclone (10) is connected to the air inlet of the first-stage air cooling cyclone (9); When the number of stages is two or more, the lower discharge port of the higher-stage air cooling cyclone is connected to the air inlet of the lower-stage air cooling cyclone, and the top air outlet of the lower-stage air cooling cyclone is connected to the air inlet of the higher-stage air cooling cyclone.

5. A method for low-temperature fluidized magnetization roasting of ilmenite using the system according to any one of claims 1 to 4, include: The ilmenite powder stored in the feed bin enters the Venturi airflow dryer and is dehydrated and dried by the hot flue gas, and then is separated from the gas and solid by the drying cyclone separator. The dried ore powder after gas-solid separation and the dried ore powder collected by the bag dust collector enter the cyclone preheater together. In the multi-stage preheating cyclone, the ore powder and the hot flue gas after the hot tail gas of the fluidized bed roasting furnace are subjected to gas-solid countercurrent heat exchange and temperature rise. The heated hot ore powder enters the roasting furnace body and undergoes oxidation magnetization roasting reaction of ilmenite with the hot air. The roasted ore powder entrained by the airflow is separated from the gas and solid by the roasting cyclone separator and then returns to the roasting furnace body. The roasted ore powder enters the highest level air cooling cyclone from the discharge port of the roasting furnace body. In the air cooling cyclone, the hot roasted ore powder and the room temperature air are subjected to gas-solid countercurrent heat exchange and temperature reduction, and finally enters the discharge bin for storage; Room temperature air enters from the lowest level air cooling cyclone for gas-solid countercurrent heat exchange with hot roasted ore powder. The hot air after heat exchange is discharged from the top outlet of the highest level air cooling cyclone into the roasting furnace body for oxidative magnetization roasting with ilmenite ore powder. The hot exhaust gas after the reaction is separated from the gas and solid by the roasting cyclone separator and enters the preheating burner. After heating with the fuel, it enters the cyclone preheater for gas-solid countercurrent heat exchange with the dry ore powder. The exhaust gas after heat exchange enters the supplementary heat burner and heats with the fuel, and then passes through the Venturi airflow dryer to dry the ilmenite ore powder, and then passes through the drying cyclone separator and bag dust collector for separation and purification before being discharged.

6. The method according to claim 5, Features: The particle size of the ilmenite powder is in the range of 0.005-9 mm. 2 The content range is 10-47wt%, the water content is less than 15wt%, and the titanium and iron elements are mainly in the form of ilmenite phase FeTiO 3 exist.

7. The method according to claim 5, Features: The temperature of the oxidation magnetization calcination reaction is 400-800° C., and the time of the oxidation magnetization calcination reaction is 5-180 minutes.

8. The method according to claim 5, Features: After the ilmenite powder is oxidized and roasted in a fluidized bed, the ilmenite phase FeTiO 3 Iron (Fe) 2+ Fe 3+ The conversion ratio ranges from 10-90%.

9. The method according to claim 5, Features: The fuel is one or at least two of fuel oil, coal, fuel gas, and coal gas.

10. The method according to claim 5, Features: The temperature of the air outlet of the drying cyclone separator is not less than 100°C, the final cooling temperature of the roasted ore powder entering the discharge bin is less than 100°C, and the temperature of the air entering the lowest level air cooling cyclone is not higher than 100°C.

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