Full-fraction ilmenite surface magnetization modification titanium extraction device and method

Abstract

The invention discloses a device and a method for extracting titanium through surface magnetization modification of full-size ilmenite, and belongs to the technical field of mineral processing and metallurgical engineering. Complete ferrotitanium recovery and separation process equipment is formed by using a suspension heating device, an oxidation reactor and a reduction reactor in cooperation with a cyclone preheater, a magnetic separator, a stirring mill and the like; according to the whole-size-fraction ilmenite, hematite is generated on the surfaces of ilmenite particles in the vanadium titano-magnetite iron separation tailings by precisely controlling key parameters, then the hematite on the surfaces of the ilmenite mineral particles is converted into magnetite through reduction treatment, a surface layer with strong magnetism is formed, then the ilmenite is separated from gangue minerals through magnetic separation, and the ferromagnetite is obtained. Synchronous magnetic separation recovery of titanium and iron is realized; and the magnetic ilmenite enters a stirring mill again, surface magnetite is ground, stripped and dissociated through scrubbing and grinding, finally separation of titanium and iron is achieved through magnetic separation again, and high-grade titanium concentrate and high-grade iron concentrate are obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of mineral processing and metallurgical engineering, and particularly relates to a device and method for surface magnetization modification and titanium extraction of ilmenite with all particle sizes. Background Art

[0002] Vanadium-titanium magnetite is a complex multi-metal associated mineral resource, and it is difficult to directly separate and extract titanium resources from it. Therefore, in industry, iron is generally selected first, and then titanium is extracted from the tailings of vanadium-titanium magnetite after iron separation. However, due to processes such as grinding and magnetic separation, the tailings of iron separation have problems such as complex ore structure and texture, serious over-grinding of ilmenite, and great difficulty in reuse. At present, the commonly used treatment methods for extracting titanium from the tailings of vanadium-titanium magnetite after iron separation are combined processes such as "gravity separation - electrostatic separation" and "magnetic separation - flotation". However, the above methods are still difficult to effectively recover ilmenite with a particle size of -0.038mm, resulting in serious loss of titanium resources; and in actual production, the flotation method requires the use of a large amount of reagents, with high production costs and great environmental pollution.

[0003] Patent CN202311770003.9 discloses a flotation process and its reagent system for enhanced recovery of ilmenite. By using hydroxamic acid and gemini quaternary ammonium salt collectors, and adopting the "one roughing - one scavenging" forward flotation and "one roughing - one scavenging" reverse flotation processes, ilmenite concentrate with a TiO 2 grade of about 47% and a TiO 2 recovery rate of about 80% can be obtained. However, this patented technology has problems such as a long flotation operation process, both forward flotation and reverse flotation, a complex reagent system, and no clear description of the applicable raw material particle size, and there is uncertainty about whether fine-grained ilmenite can be successfully separated.

[0004] Patent CN202010873387.7 discloses a method for titanium extraction and impurity reduction from the tailings of vanadium-titanium magnetite after iron separation. By flexibly combining high-intensity magnetic separation, flotation and classification, the purpose of classifying and recovering ilmenite in the tailings of vanadium-titanium magnetite after iron separation according to different particle sizes is achieved. Finally, ilmenite concentrate products with a TiO 2 grade of 48.27% and a TiO 2 recovery rate of 53.95% can be obtained. However, due to a large number of classification and separation operations in this patented technology, there are many types of obtained products, and the process flow is too complicated, which is not conducive to industrial application and implementation.

[0005] Therefore, aiming at the problems of uneven particle sizes of ilmenite, poor recovery effect of "high-intensity magnetic separation + flotation", and too long process flow, it is urgent to develop a beneficiation process plan for ilmenite with all particle sizes to achieve the efficient recovery of ilmenite, which is of great significance for greatly improving the recovery rate of ilmenite in the Panxi region. Summary of the Invention

[0006] Aiming at the problem that the existing "high-intensity magnetic separation + flotation" process has poor adaptability to all particle sizes, especially the fine-grained ilmenite will deteriorate the flotation index, and even cause the flotation operation to be unable to run normally in severe cases, the present invention provides a device and method for surface magnetization modification of ilmenite in all particle sizes to extract titanium. The main principle is to use the method of "pre-oxidation - re-reduction" mineral phase transformation to realize the surface magnetization modification of ilmenite particles in the tailings of vanadium-titanium magnetite after iron separation, thereby improving the magnetism of ilmenite particles as a whole and laying a mineralogical condition for the magnetic separation and recovery of ilmenite. Specifically: by connecting and coordinating equipment such as a suspension heating device, an oxidation device, a reduction device, and a cyclone separator, and regulating the reaction conditions, the ilmenite on the surface of the tailings of vanadium-titanium magnetite after iron separation is modified to generate magnetite with strong magnetism, and then the ilmenite wrapped by magnetite is synchronously recovered and asynchronously separated by a magnetic separator and a grinding device, and finally qualified titanium concentrate and iron concentrate products are obtained, realizing the efficient recovery of ilmenite in the tailings of vanadium-titanium magnetite after iron separation. Only the surface characteristics of ilmenite particles are changed during the whole process, and the internal phase composition and other properties of the particles do not change significantly, minimizing the process energy consumption.

[0007] A device for surface magnetization modification of ilmenite in all particle sizes to extract titanium, comprising a feed bin, a belt, a screw feeder, a cyclone preheater, a suspension heating furnace, a first cyclone separator, an oxidation reactor, a second cyclone separator, a reduction reactor, a third cyclone separator, a water quenching and stirring pulp tank, a first magnetic separator, a stirred mill, a second magnetic separator, a condensation device, a desulfurization and denitration device, a Roots blower, a chimney and a burner.

[0008] The feed bin, the belt and the screw feeder are connected in sequence, and the discharge port of the screw feeder is connected to the feed port of the cyclone preheater through a pipeline; the discharge port of the cyclone preheater is connected to the feed port of the suspension heating furnace through a pipeline; the bottom of the suspension heating furnace is connected to the burner, and the discharge port of the suspension heating furnace is connected to the feed port of the first cyclone separator through a pipeline; the gas outlet of the first cyclone separator is connected to the gas inlet of the cyclone preheater through a pipeline, and the discharge port of the first cyclone separator is connected to the feed port of the oxidation reactor through a pipeline, and the discharge port of the oxidation reactor is connected to the feed port of the second cyclone separator through a pipeline; the discharge port of the second cyclone separator is connected to the feed port of the reduction reactor through a pipeline, the discharge port of the reduction reactor is connected to the feed port of the third cyclone separator through a pipeline, the discharge port of the third cyclone separator is connected to the feed port of the water quenching and stirring pulp tank through a pipeline, the discharge port of the water quenching and stirring pulp tank is connected to the feed port of the first magnetic separator through a pipeline, the discharge port of the first magnetic separator is connected to the feed port of the stirred mill through a pipeline, and the discharge port of the stirred mill is connected to the feed port of the second magnetic separator through a pipeline; the gas outlet of the cyclone preheater is connected to the gas inlet of the condensation device through a pipeline, the condensation device is connected to the desulfurization and denitration device through a pipeline, and the desulfurization and denitration device is connected to the Roots blower and the chimney in sequence.

[0009] Further, the gas outlets of the second cyclone separator and the third cyclone separator are connected to the burner through pipelines.

[0010] Further, a partition is provided at the bottom of the oxidation reactor, dividing the interior of the oxidation reactor into a fluidized chamber and an oxidation chamber. The feed inlet is located at the upper part of the fluidized chamber. The bottoms of both chambers are connected to an air pipe to introduce air, and the air flow in the fluidized chamber is less than that in the oxidation chamber.

[0011] Further, a partition is provided at the bottom of the reduction reactor, dividing the interior of the reduction reactor into a fluidized chamber and a reduction chamber. The upper part of the fluidized chamber is the feed inlet of the reduction reactor, and the upper part of the reduction chamber is the discharge outlet of the reduction reactor. Air inlets are respectively provided at the bottoms of the fluidized chamber and the reduction chamber, and are connected to the reduction gas pipe and the nitrogen pipeline.

[0012] Further, the first magnetic separator is also provided with a tailings outlet.

[0013] A method for surface magnetization modification of ilmenite for titanium extraction with all particle sizes is realized by using the above device and is carried out according to the following steps:

[0014] Step 1: Place the all-particle-size ilmenite (iron tailings from vanadium-titanium magnetite iron separation) material in the silo and feed it into the screw feeder through the belt conveyor.

[0015] Step 2: Start the burner, introduce natural gas and air into the burner, and the high-temperature flue gas enters the suspension heating furnace, and then successively enters the first cyclone separator, the cyclone preheater, the condensation equipment, the desulfurization and denitrification device, the Roots blower, and finally is discharged through the chimney.

[0016] Step 3: Start the screw feeder, the water quenching stirring and slurrying tank, the first magnetic separator, the stirring mill, and the second magnetic separator; feed air into the bottom of the oxidation reactor, and feed reducing gas and nitrogen into the bottom of the reduction reactor. The reaction products of the oxidation reactor and the reduction reactor are respectively subjected to gas-solid separation by the second cyclone separator and the third cyclone separator. The gas therein is discharged through the gas outlet of the cyclone separator and then enters the burner through a pipeline. The all-size ilmenite (iron tailings from vanadium-titanium magnetite iron separation) material is fed into the cyclone preheater by the screw feeder for preheating. The preheating time is 1 min to 2 min, and the temperature is 300°C to 400°C. After preheating, the material enters the suspension heating furnace. After being heated by the suspension heating furnace, it enters the first cyclone separator. The first cyclone separator separates the solid material from the gas. The solid material enters the oxidation reactor for oxidation reaction by using its own stored heat, oxidizes and decomposes the surface of the ilmenite particles to generate rutile and hematite. The oxidized solid material enters the second cyclone separator with the air flow for gas-solid separation. The separated gas enters the burner as combustion gas, and the separated solid material enters the reduction reactor, where a reduction reaction occurs by using its own stored heat, reducing the hematite formed on the surface of the ilmenite particles to strongly magnetic magnetite, thereby overall improving the magnetism of the ilmenite particles. The reduced solid material enters the third cyclone separator with the air flow, and the separated gas enters the burner as fuel for combustion and heat supply.

[0017] Step 4: The solid material separated by the third cyclone separator enters the water quenching stirring and slurrying tank for cooling and slurrying, and then enters the first magnetic separator for primary magnetic separation, separating the surface magnetized modified ilmenite and gangue minerals, realizing the synchronous recovery of iron and titanium and the efficient rejection of gangue. The separated gas enters the burner as fuel for combustion and heat supply. The surface magnetized modified ilmenite obtained after primary magnetic separation enters the stirring mill for scrubbing and grinding, stripping and dissociating the magnetite shell layer on the surface of the ilmenite particles. The grinding product enters the second magnetic separator for secondary magnetic separation, obtaining non-magnetic ilmenite concentrate and magnetic iron concentrate products, realizing the separation and comprehensive recovery of iron and titanium.

[0018] Further, the grade of the all-size ilmenite (iron tailings from vanadium-titanium magnetite iron separation) described in Step 1 is TFe 10% - 30%, TiO 2 5% - 25%, and the moisture content ≤ 10%; the particle size is such that the proportion of -200 mesh is ≥ 80%, and the proportion of -400 mesh in the particle size is more than 30%.

[0019] Further, the heating temperature of the suspension heating furnace described in Step 3 is 700°C - 900°C, and the heating time is 1 min - 10 min; the temperature in the oxidation reactor is 600°C - 850°C, and the oxidation reaction time is 10 min - 40 min; the temperature in the reduction reactor is 450°C - 550°C, and the reduction reaction time is 5 min - 20 min.

[0020] Further, the reducing gas used in the reduction reaction in Step 3 is H produced by coal gasification or natural gas cracking 2 and CO, which oxidize Fe in the solid material 2 O 3 The molar ratio of to the reducing gas is 0.5 - 1.0; the oxidizing gas is a mixed gas configured with oxygen and nitrogen, and the oxygen concentration is not less than 20%, or air is directly introduced.

[0021] Further, in Step 3, the chemical equations of the oxidation reaction and the reduction chemical reaction occurring on the surface of ilmenite particle minerals are as follows:

[0022] 4FeTiO 3 +O 2 =2Fe 2 O 3 +4TiO 2 (1)

[0023] 3Fe 2 O 3 +CO / H 2 =2Fe 3 O 4 +CO 2 / H 2 O (2)

[0024] In the reduced solid material, the titanium in the ilmenite particle core still exists in the forms of TiO 2 and ilmenite (FeTiO 3 ).

[0025] Further, in Step 4, the concentration of the solid material in the water quenching and stirring pulp tank is 20% - 35%, the temperature of the pulp after cooling should be lower than 80°C, and the magnetic field intensities of the first magnetic separation and the second magnetic separation are 500 Oe - 2000 Oe.

[0026] Further, in Step 4, the pulp concentration in the stirred mill is 30% - 45%, and the proportion of -325 mesh in the grinding product is ≥80%.

[0027] Further, in Step 4, the TiO 2 grade in the obtained titanium concentrate product is ≥47%, the TiO 2 recovery rate is ≥70%, and the iron concentrate grade is ≥65%.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] The basic principle of the present invention is to form a complete titanium-iron recovery and separation process equipment by using a suspension heating device, an oxidation reactor, and a reduction reactor, in cooperation with a cyclone preheater, a magnetic separator, a stirring mill, etc. The whole particle size ilmenite (iron separation tailings of vanadium-titanium magnetite) generates hematite on the surface of ilmenite particles in the iron separation tailings of vanadium-titanium magnetite by precisely controlling key parameters such as oxidation temperature, atmosphere, and time. Then, through reduction treatment, the hematite on the surface of ilmenite mineral particles is converted into magnetite, forming a strongly magnetic surface layer. Subsequently, the ilmenite wrapped by magnetite is separated from gangue minerals through magnetic separation, realizing the synchronous magnetic separation recovery of titanium and iron. The obtained magnetic ilmenite then enters the stirring mill, and the surface magnetite is ground and dissociated by scrubbing and grinding. Finally, the separation of titanium and iron is realized again through magnetic separation, obtaining high-grade titanium concentrate and iron concentrate.

[0030] Compared with the existing methods and devices for treating iron separation tailings of vanadium-titanium magnetite, the present invention first uses a suspension heating furnace to fluidize heat and react the materials, with high heat and mass transfer efficiency and fast reaction rate. By utilizing the self-heat storage and reaction heat release of minerals, the spontaneous progress of the oxidation and reduction processes is realized, effectively reducing the roasting energy consumption. Secondly, the innovation of the device and method of the present invention is to utilize the self-properties of ilmenite minerals, and selectively convert the surface of ilmenite particles into magnetite by precisely regulating the reaction conditions, without over-oxidation and over-reduction reactions, realizing the surface magnetization modification of ilmenite mineral particles. In combination with traditional beneficiation processes such as magnetic separation and grinding, the separation and comprehensive recovery of titanium and iron are realized. In addition, the method of the present invention does not require grading treatment of the iron separation tailings of vanadium-titanium magnetite, realizing the utilization of the whole particle size, effectively simplifying the process flow. The whole set of device and method is designed to recycle heat, save energy and reduce consumption, with low production cost, and is convenient for industrial implementation and application. Description of the Drawings

[0031] Figure 1 Schematic diagram of a device for surface magnetization modification of whole particle size ilmenite to extract titanium according to the present invention;

[0032] In the figure: 1. Feed bin; 2. Belt; 3. Screw feeder; 4. Cyclone preheater; 5. Suspension heating furnace; 6. First cyclone separator; 7. Oxidation reactor; 8. Second cyclone separator; 9. Reduction reactor; 10. Third cyclone separator; 11. Quenching and stirring slurry tank; 12. First magnetic separator; 13. Stirring mill; 14. Second magnetic separator; 15. Condensing equipment; 16. Desulfurization and denitrification device; 17. Roots blower; 18. Chimney; 19. Burner. Detailed Embodiments

[0033] To further describe the present invention, the technical solutions of the present invention will be further elaborated below with reference to the drawings and embodiments.

[0034] In the cyclone preheater of the present invention, the preheating temperature of the iron ore tailings is 300°C to 400°C.

[0035] During the process of the solid materials of the present invention passing through the suspension heating furnace, the oxidation reactor and the reduction reactor, the temperature gradually decreases, and the temperature entering the magnetic separator is not higher than 60°C.

[0036] The oxygen and nitrogen used in the present invention have a purity greater than 95%.

[0037] The present invention preferably uses a stirred mill or an Isa mill, but using other mills to achieve the same effect should be regarded as the same method as the present invention.

[0038] Example 1

[0039] A device for surface magnetization modification of ilmenite with all particle sizes for titanium extraction, as Figure 1 shown, includes a silo 1, a belt 2, a screw feeder 3, a cyclone preheater 4, a suspension heating furnace 5, a first cyclone separator 6, an oxidation reactor 7, a second cyclone separator 8, a reduction reactor 9, a third cyclone separator 10, a water quenching and stirring pulp tank 11, a first magnetic separator 12, a stirred mill 13, a second magnetic separator 14, a condensation device 15, a desulfurization and denitration device 16, a Roots blower 17, a chimney 18 and a burner 19.

[0040] The discharge port of the storage bin 1 feeds the belt 2, and the belt 2 is connected to the feed inlet of the screw feeder 3; the discharge port of the screw feeder 3 is connected to the feed inlet of the cyclone preheater 4 through a pipeline; the discharge port of the cyclone preheater 4 is connected to the feed inlet of the suspension heating furnace 5 through a pipeline; the bottom of the suspension heating furnace 5 is connected to the burner 19, and the discharge port of the suspension heating furnace 5 is connected to the feed inlet of the first cyclone separator 6 through a pipeline; the discharge port of the first cyclone separator 6 is connected to the feed inlet of the oxidation reactor 7 through a pipeline; a partition plate (porous quartz plate) is provided at the bottom of the oxidation reactor 7 to divide the interior of the oxidation reactor 7 into a fluidization chamber and an oxidation chamber. The feed inlet is arranged at the upper part of the fluidization chamber, and the bottoms of the two chambers are connected to an air pipe to introduce air. Among them, the air flow in the fluidization chamber is smaller than that in the oxidation chamber. The discharge port of the oxidation reactor 7 is connected to the feed inlet of the second cyclone separator 8 through a pipeline; the discharge port of the second cyclone separator 8 is connected to the feed inlet of the reduction reactor 9 through a pipeline. A partition plate is provided at the bottom of the reduction reactor 9 to divide the interior of the reduction reactor 9 into a fluidization chamber and a magnetization chamber. The feed inlet of the reduction reactor 9 is arranged at the upper part of the fluidization chamber, and the discharge port is arranged at the upper part of the magnetization chamber. Ventilation openings are respectively provided at the bottoms of the fluidization chamber and the magnetization chamber and are connected to the reduction gas pipeline and the nitrogen pipeline; the discharge port of the reduction reactor 9 is connected to the feed inlet of the third cyclone separator 10 through a pipeline, and the discharge port of the third cyclone separator 10 is connected to the feed inlet of the water quenching and stirring pulp tank 11 through a pipeline; the discharge port of the water quenching and stirring pulp tank 11 is connected to the feed inlet of the first magnetic separator 12 through a pipeline, the discharge port of the first magnetic separator 12 is connected to the feed inlet of the stirring mill 13 through a pipeline, and the discharge port of the stirring mill 13 is connected to the feed inlet of the second magnetic separator 14 through a pipeline.

[0041] The gas outlet of the first cyclone separator 6 is connected to the gas inlet of the cyclone preheater 4 through a pipeline, and the gas outlets of the second cyclone separator 8 and the third cyclone separator 10 are connected to the burner 19 through a pipeline.

[0042] The gas outlet of the cyclone preheater 4 is connected to the gas inlet of the condensation device 15 through a pipeline. The condensation device 15 is connected to the desulfurization and denitrification device 16 through a pipeline, and the desulfurization and denitrification device 16, the Roots blower 17 and the chimney 18 are connected in sequence.

[0043] A method for surface magnetization modification of ilmenite to extract titanium with all particle sizes is realized by using the above-mentioned titanium extraction device and is carried out according to the following steps:

[0044] Step 1: Place all-particle-size ilmenite materials with a TFe grade of 10.5%, a TiO 2 grade of 20.5%, a moisture content of 9%, a particle size of -200 mesh accounting for 90%, and a particle size of -400 mesh accounting for 45% in the storage bin 1, and feed them into the screw feeder 3 through the belt 2.

[0045] Step 2: Start the burner 19, introduce natural gas and air into the burner 19, the high-temperature flue gas enters the suspension heating furnace 5, and then enters the first cyclone separator 6, the cyclone preheater 4, the condensation device 15, the desulfurization and denitrification device 16, the Roots blower 17, and finally is discharged through the chimney 18.

[0046] Step 3: Start the screw feeder 3, start the water quenching stirring and slurrying tank 11, the first magnetic separator 12, the stirring mill 13 and the second magnetic separator 14; air is fed into the bottom of the oxidation reactor 7, and reducing gas and nitrogen are fed into the bottom of the reduction reactor 9. The reaction products of the oxidation reactor 7 and the reduction reactor 9 are respectively subjected to gas-solid separation by the second cyclone separator 8 and the third cyclone separator 10. The gas is discharged from the gas outlet of the cyclone separator and then enters the burner 19 through a pipeline. The whole particle size ilmenite material is fed into the cyclone preheater 4 from the screw feeder 3 for preheating. The preheating time is 2 min and the temperature is 300 °C. After preheating, the material enters the suspension heating furnace 5, and the temperature in the suspension heating furnace 5 is 900 °C, and the heating time is 2 min. After being heated by the suspension heating furnace 5, it enters the first cyclone separator 6. The first cyclone separator 6 separates the solid material from the gas. The solid material uses its own heat storage to enter the oxidation reactor 7 to carry out an oxidation reaction. The oxidation gas is air, and the temperature in the oxidation reactor 7 is 750 °C, and the oxidation residence time is 30 min. The oxidation product enters the second cyclone separator 8 with the gas flow for gas-solid separation. The separated gas enters the burner 19 as combustion gas, and the separated solid material enters the reduction reactor 9 and uses its own heat storage to carry out a reduction reaction. The reducing gas is H 2 and / or CO produced by the cracking of natural gas. The temperature in the reduction reactor 9 is 550 °C, and the residence time in the reduction reactor 9 is 8 min. The molar ratio of the Fe 2 O 3 content in the oxidation product to the total amount of reducing gas is 0.8. The reduction product enters the third cyclone separator 10 with the gas flow, and the separated gas enters the burner 19.

[0047] During the process, check whether there is blockage in the pipeline, whether the material in the suspension heating furnace 5 is in a suspended state, whether the materials in the oxidation reactor 7 and the reduction reactor 9 are in a fluidized state, and whether there is blockage.

[0048] Step 4: The materials separated by the third cyclone separator 10 enter the water quenching and stirring pulp tank 11 for cooling. The concentration of solid materials in the water quenching and stirring pulp tank 11 is about 35%. After cooling, the temperature of the materials is 60°C, and then they enter the first magnetic separator 12 to separate ilmenite and gangue minerals obtained after surface magnetization. The gangue is tailings discharged, and the surface-magnetized ilmenite enters the stirring mill 13 to grind off the surface magnetic iron. The material concentration in the stirring mill 13 is 40%, and the proportion of -325 mesh in the grinding product is 85%. The obtained materials enter the second magnetic separator 14 for secondary magnetic separation, and the magnetic field intensity of the magnetic separation is 1000 Oe, to obtain titanium concentrate and iron concentrate.

[0049] The TiO in the finally obtained titanium concentrate product 2 grade is 47.82%, the recovery rate is 85.3%, and the grade of the iron concentrate is 66.52%.

[0050] Example 2

[0051] A method for surface magnetization modification of ilmenite for titanium extraction with all particle sizes is realized by using the titanium extraction device of Example 1, and is carried out according to the following steps:

[0052] Step 1: The all-particle-size ilmenite materials with a TFe grade of 12.8%, a TiO 2 grade of 21.2%, a moisture content of 9%, a particle size of -200 mesh accounting for 90%, and a mass proportion of -400 mesh of 70% are placed in the bin 1 and fed into the screw feeder 3 through the belt 2.

[0053] Step 2: Start the burner 19, introduce natural gas and air into the burner 19, the high-temperature flue gas enters the suspension heating furnace 5, and then enters the first cyclone separator 6, the cyclone preheater 4, the condensation device 15, the desulfurization and denitrification device 16, the Roots blower 17 in sequence, and finally is discharged through the chimney 18.

[0054] Step 3: Start the screw feeder 3, and start the water quenching stirring and pulp mixing tank 11, the first magnetic separator 12, the stirring mill 13 and the second magnetic separator 14; Feed air into the bottom of the oxidation reactor 7, and feed reducing gas and nitrogen into the bottom of the reduction reactor 9. The reaction products of the oxidation reactor 7 and the reduction reactor 9 are respectively subjected to gas-solid separation by the second cyclone separator 8 and the third cyclone separator 10. The gas is discharged from the gas outlet of the cyclone separator and then enters the burner 19 through a pipeline. The whole-size ilmenite material is fed into the cyclone preheater 4 by the screw feeder 3 for preheating. The preheating time is 2 min and the temperature is 320 °C. After preheating, the material enters the suspension heating furnace 5, and the temperature in the suspension heating furnace 5 is 850 °C, and the heating time is 2 min. After being heated by the suspension heating furnace 5, it enters the first cyclone separator 6. The first cyclone separator 6 separates the solid material from the gas. The solid material enters the oxidation reactor 7 by using its own heat storage to carry out an oxidation reaction. The oxidation gas is air, and the temperature in the oxidation reactor 7 is 720 °C, and the oxidation residence time is 30 min. The oxidation product enters the second cyclone separator 8 with the gas flow for gas-solid separation. The separated gas enters the burner 19 as combustion gas, and the separated solid material enters the reduction reactor 9 and uses its own heat storage to carry out a reduction reaction. The reducing gas is H 2 and / or CO produced by the cracking of natural gas. The temperature in the reduction reactor 9 is 500 °C, and the residence time in the reduction reactor 9 is 10 min. The molar ratio of the Fe 2 O 3 content in the oxidation product to the total amount of reducing gas is 0.7. The reduction product enters the third cyclone separator 10 with the gas flow, and the separated gas enters the burner 19.

[0055] During the process, check whether there is blockage in the pipeline, whether the material in the suspension heating furnace 5 is in a suspended state, whether the materials in the oxidation reactor 7 and the reduction reactor 9 are in a fluidized state, and whether there is blockage.

[0056] Step 4: The material separated by the third cyclone separator 10 enters the water quenching stirring and pulp mixing tank 11 for cooling. The concentration of the solid material in the water quenching stirring and pulp mixing tank 11 is about 35%. After cooling, the temperature of the material is 60 °C and it enters the first magnetic separator 12. The ilmenite and gangue minerals obtained after surface magnetization are separated. The gangue is discarded, and the ilmenite after surface magnetization enters the stirring mill 13 to grind off the surface magnetic iron. The material concentration in the stirring mill 13 is 40%, and the proportion of -325 mesh in the grinding product is 85%. The material enters the second magnetic separator 14 for secondary magnetic separation. The magnetic field intensity of both magnetic separations is 1200 Oe, and ilmenite concentrate and iron concentrate are obtained.

[0057] The TiO 2 grade in the finally obtained ilmenite concentrate is 48.15%, the recovery rate is 82.12%, and the grade of the iron concentrate is 68.2%.

[0058] Example 3

[0059] A method for extracting titanium by surface magnetization modification of ilmenite with all particle sizes, which is realized by using the titanium extraction device of Example 1, and is carried out according to the following steps:

[0060] Step 1: Place ilmenite materials with all particle sizes having a TFe grade of 12.5%, a TiO 2 grade of 16.8%, a moisture content of 6%, a particle size of -200 mesh accounting for 93%, and a particle size of -400 mesh with a mass fraction of 70% in the silo 1, and feed them into the screw feeder 3 through the belt 2.

[0061] Step 2: Start the burner 19, introduce natural gas and air into the burner 19, the high-temperature flue gas enters the suspension heating furnace 5, and then enters the first cyclone separator 6, the cyclone preheater 4, the condensation device 15, the desulfurization and denitration device 16, the Roots blower 17 in sequence, and finally is discharged through the chimney 18.

[0062] Step 3: Start the screw feeder 3, start the water quenching and stirring slurry tank 11, the first magnetic separator 12, the stirring mill 13 and the second magnetic separator 14; air is fed into the bottom of the oxidation reactor 7, and reducing gas and nitrogen are fed into the bottom of the reduction reactor 9. The reaction products of the oxidation reactor 7 and the reduction reactor 9 are respectively subjected to gas-solid separation by the second cyclone separator 8 and the third cyclone separator 10. The gas is discharged from the gas outlet of the cyclone separator and then enters the burner 19 through the pipeline. The ilmenite materials with all particle sizes are fed from the screw feeder 3 into the cyclone preheater 4 for preheating. The preheating time is 2 min and the temperature is 360 °C. After preheating, the materials enter the suspension heating furnace 5, and the temperature in the suspension heating furnace 5 is 880 °C, and the heating time is 2 min. After being heated by the suspension heating furnace 5, it enters the first cyclone separator 6. The first cyclone separator 6 separates the solid materials from the gas. The solid materials enter the oxidation reactor 7 by using their own heat storage to carry out an oxidation reaction. The oxidation gas is air, and the temperature in the oxidation reactor 7 is 740 °C, and the oxidation residence time is 30 min. The oxidation products enter the second cyclone separator 8 with the air flow for gas-solid separation. The separated gas enters the burner 19 as combustion gas, and the separated solid materials enter the reduction reactor 9, and use their own heat storage to carry out a reduction reaction. The reducing gas is H 2 and / or CO produced by the cracking of natural gas. The temperature in the reduction reactor 9 is 520 °C, and the residence time in the reduction reactor 9 is 12 min. The molar ratio of the Fe 2 O 3 content in the oxidation products to the total amount of the reducing gas is 0.9. The reduction products enter the third cyclone separator 10 with the air flow, and the separated gas enters the burner 19.

[0063] During the process, check whether there is blockage in the pipeline, whether the materials in the suspension heating furnace 5 are in a suspended state, and whether the materials in the oxidation reactor 7 and the reduction reactor 9 are in a fluidized state and whether there is blockage.

[0064] Step 4: The materials separated by the third cyclone separator 10 enter the water quenching stirring and pulp adjusting tank 11 for cooling. The solid material concentration in the water quenching stirring and pulp adjusting tank 11 is about 35%. After cooling, the material temperature is 60°C. Then it enters the first magnetic separator 12 to separate ilmenite and gangue minerals obtained after surface magnetization. The gangue is tailings discharged, and the surface-magnetized ilmenite enters the stirring mill 13 to grind off the surface magnetic iron. The material concentration in the stirring mill 13 is 35%, and the proportion of -325 mesh in the grinding product is 87%. The materials enter the second magnetic separator 14 for secondary magnetic separation, and the magnetic field intensity of both magnetic separations is 1200 Oe to obtain titanium concentrate and iron concentrate.

[0065] The TiO in the finally obtained titanium concentrate 2 grade is 48.54%, the recovery rate is 81.75%, and the grade of the iron concentrate is 67.75%.

[0066] Example 4

[0067] A method for surface magnetization modification of ilmenite to extract titanium with all particle sizes is realized by using the titanium extraction device of Example 1 and is carried out according to the following steps:

[0068] Step 1: Place all-particle-size ilmenite materials with a TFe grade of 11.58%, a TiO 2 grade of 15.5%, a moisture content of 6%, a particle size of -200 mesh accounting for 95%, and a particle size of -400 mesh mass accounting for 75% in the silo 1 and feed them into the screw feeder 3 through the belt 2.

[0069] Step 2: Start the burner 19, introduce natural gas and air into the burner 19. The high-temperature flue gas enters the suspension heating furnace 5 and then successively enters the first cyclone separator 6, the cyclone preheater 4, the condensation device 15, the desulfurization and denitrification device 16, the Roots blower 17, and finally is discharged through the chimney 18.

[0070] Step 3: Start the screw feeder 3, the water quenching stirring and pulp adjusting tank 11, the first magnetic separator 12, the stirring mill 13 and the second magnetic separator 14; Feed air into the bottom of the oxidation reactor 7, and feed reducing gas and nitrogen into the bottom of the reduction reactor 9. The reaction products of the oxidation reactor 7 and the reduction reactor 9 are respectively subjected to gas-solid separation by the second cyclone separator 8 and the third cyclone separator 10. The gas is discharged from the gas outlet of the cyclone separator and then enters the burner 19 through a pipeline. The whole particle size ilmenite material is fed into the cyclone preheater 4 by the screw feeder 3 for preheating. The preheating time is 2 min and the temperature is 310 °C. After preheating, the material enters the suspension heating furnace 5. The temperature in the suspension heating furnace 5 is 900 °C and the heating time is 1.5 min. After being heated by the suspension heating furnace 5, it enters the first cyclone separator 6. The first cyclone separator 6 separates the solid material from the gas. The solid material enters the oxidation reactor 7 by using its own heat storage to carry out an oxidation reaction. The oxidation gas is air. The temperature in the oxidation reactor 7 is 740 °C and the oxidation residence time is 20 min. The oxidation product enters the second cyclone separator 8 with the air flow for gas-solid separation. The separated gas enters the burner 19 as combustion gas, and the separated solid material enters the reduction reactor 9 and uses its own heat storage to carry out a reduction reaction. The reducing gas is H 2 and / or CO. The temperature in the reduction reactor 9 is 500 °C and the residence time in the reduction reactor 9 is 10 min. The molar ratio of the Fe 2 O 3 content in the oxidation product to the total amount of the reducing gas is 1. The reduction product enters the third cyclone separator 10 with the air flow, and the separated gas enters the burner 19.

[0071] During the process, check whether there is blockage in the pipeline, whether the material in the suspension heating furnace 5 is in a suspended state, whether the material in the oxidation reactor 7 and the reduction reactor 9 is in a fluidized state, and whether there is blockage.

[0072] Step 4: The material separated by the third cyclone separator 10 enters the water quenching stirring and pulp adjusting tank 11 for cooling. The concentration of the solid material in the water quenching stirring and pulp adjusting tank 11 is about 35%. After cooling, the temperature of the material is 60 °C and it enters the first magnetic separator 12. The ilmenite and gangue minerals obtained after surface magnetization are separated. The gangue is tailing discharged, and the ilmenite after surface magnetization enters the stirring mill 13 to grind off the surface magnetic iron. The material concentration in the stirring mill 13 is 35%, and the proportion of -325 mesh in the grinding product is 80%. The material enters the second magnetic separator 14 for secondary magnetic separation. The magnetic field intensity of both magnetic separations is 1500 Oe, and ilmenite concentrate and iron concentrate are obtained.

[0073] The TiO 2 grade in the finally obtained ilmenite concentrate is 48.85%, the recovery rate is 81.33%, and the grade of the iron concentrate is 70.2%.

Claims

1. A device for extracting titanium by magnetizing and modifying the surface of full-grained ilmenite, characterized in that: It comprises a silo (1), a belt (2), a screw feeder (3), a cyclone preheater (4), a suspension heating furnace (5), a first cyclone separator (6), an oxidation reactor (7), a second cyclone separator (8), a reduction reactor (9), a third cyclone separator (10), a water quenching stirring slurry mixing tank (11), a first magnetic separator (12), a stirring mill (13), a second magnetic separator (14), a condensing device (15), a desulfurization and denitration device (16), a Roots blower (17), a chimney (18) and a burner (19); The silo (1), the belt (2), and the screw feeder (3) are connected in sequence; the discharge port of the screw feeder (3) is connected to the feed port of the cyclone preheater (4) through a pipeline; the discharge port of the cyclone preheater (4) is connected to the feed port of the suspension heating furnace (5) through a pipeline; the bottom of the suspension heating furnace (5) is connected to a burner (19), and the discharge port of the suspension heating furnace (5) is connected to the feed port of the first cyclone separator (6) through a pipeline; the air outlet of the first cyclone separator (6) is connected to the air inlet of the cyclone preheater (4) through a pipeline, the discharge port of the first cyclone separator (6) is connected to the feed port of the oxidation reactor (7) through a pipeline, and the discharge port of the oxidation reactor (7) is connected to the feed port of the second cyclone separator (8) through a pipeline; the discharge port of the second cyclone separator (8) is connected to the return reactor (4) through a pipeline. The feed port of the original reactor (9) is connected, the discharge port of the reduction reactor (9) is connected to the feed port of the third cyclone separator (10) through a pipeline, the discharge port of the third cyclone separator (10) is connected to the feed port of the water quenching stirring slurry mixing tank (11) through a pipeline, the discharge port of the water quenching stirring slurry mixing tank (11) is connected to the feed port of the first magnetic separator (12) through a pipeline, the discharge port of the first magnetic separator (12) is connected to the feed port of the stirring mill (13) through a pipeline, and the discharge port of the stirring mill (13) is connected to the feed port of the second magnetic separator (14) through a pipeline; the air outlet of the cyclone preheater (4) is connected to the air inlet of the condensing device (15) through a pipeline, the condensing device (15) is connected to the desulfurization and denitration device (16) through a pipeline, and the desulfurization and denitration device (16), the Roots blower (17) and the chimney (18) are connected in sequence.

2. The device for extracting titanium by surface magnetization modification of full-grained ilmenite according to claim 1, characterized in that: The air outlets of the second cyclone separator (8) and the third cyclone separator (10) are connected to the burner via pipelines.

3. The device for extracting titanium by magnetizing and modifying the surface of full-grained ilmenite according to claim 1, characterized in that: The oxidation reactor (7) is provided with a partition at the bottom, dividing the interior of the oxidation reactor (7) into a fluidizing chamber and an oxidation chamber. The feed inlet is located at the upper part of the fluidizing chamber. The bottoms of the two chambers are connected to an air pipe for introducing air. The airflow in the fluidizing chamber is smaller than that in the oxidation chamber.

4. The device for extracting titanium by magnetizing and modifying the surface of full-grained ilmenite according to claim 1, characterized in that: The reduction reactor (9) is provided with a partition at the bottom thereof, dividing the reduction reactor (9) into a fluidizing chamber and a reduction chamber. The upper portion of the fluidizing chamber is a feed inlet of the reduction reactor (9), and the upper portion of the reduction chamber is a discharge outlet of the reduction reactor (9). Air inlets are provided at the bottom of the fluidizing chamber and the reduction chamber, respectively, and are connected to a reduction air pipe and a nitrogen pipe.

5. A method for extracting titanium by surface magnetization modification of full-grained ilmenite, implemented by the device according to any one of claims 1 to 4, characterized in that: Follow these steps: Step 1: placing full-grained ferro-titanium ore material in a silo (1) and feeding it into a screw feeder (3) via a belt (2); Step 2: Start the burner (19), introduce natural gas and air into the burner (19), and the high-temperature flue gas enters the suspension heating furnace (5), and then enters the first cyclone separator (6), the cyclone preheater (4), the condensing device (15), the desulfurization and denitrification device (16), the Roots blower (17), and finally is discharged through the chimney (18); Step 3: Start the screw feeder (3), start the water quenching stirring slurry tank (11), the first magnetic separator (12), the stirred mill (13) and the second magnetic separator (14); feed air into the bottom of the oxidation reactor (7), and feed reducing gas and nitrogen into the bottom of the reduction reactor (9); the reaction products of the oxidation reactor (7) and the reduction reactor (9) are respectively separated into gas and solid by passing through the second cyclone separator (8) and the third cyclone separator (10); the gas is discharged through the gas outlet of the cyclone separator and then enters the burner (19) through the pipeline; the full-grained ferroilite material is fed from the screw feeder (3) into the cyclone preheater (4) for preheating, the preheating time is 1min to 2min, the temperature is 300°C to 400°C, and the preheated material enters the suspension heating furnace (5) After being heated by the suspension heating furnace (5), the solid material enters the first cyclone separator (6), and the first cyclone separator (6) separates the solid material from the gas. The solid material uses its own heat storage to enter the oxidation reactor (7) for oxidation reaction, and the surface of the ilmenite particles is oxidized and decomposed to generate rutile and hematite. The oxidized solid material enters the second cyclone separator (8) with the airflow for gas-solid separation, and the separated gas enters the burner (19) as combustion gas. The separated solid material enters the reduction reactor (9), and uses its own heat storage to generate a reduction reaction, and the hematite generated on the surface of the ilmenite particles is reduced to magnetite with strong magnetism. The reduced solid material enters the third cyclone separator (10) with the airflow, and the separated gas enters the burner (19) as fuel for combustion and heat supply; Step 4: The solid material separated by the third cyclone separator (10) enters a water quenching stirring slurry tank (11) for cooling and slurry preparation, and then enters a first magnetic separator (12) for primary magnetic separation to separate the surface magnetized modified ilmenite and gangue minerals, thereby realizing the simultaneous recovery of iron and titanium and the efficient removal of gangue, and the separated gas enters a burner (19) for combustion as fuel for heat supply; the surface magnetized modified ilmenite obtained after the primary magnetic separation enters a stirred mill (13) for scrubbing and grinding, and the magnetite shell layer on the surface of the ilmenite particles is ground and dissociated, and the grinding product enters a second magnetic separator (14) for secondary magnetic separation to obtain non-magnetic titanium concentrate and magnetic iron concentrate products, thereby realizing the separation and comprehensive recovery of iron and titanium.

6. The method for extracting titanium by surface magnetization modification of full-grained ilmenite according to claim 5, characterized in that: The full-grained ilmenite grade in step 1 is TFe 10%-30%, TiO2 5%-25%, and moisture ≤10%; the particle size of -200 mesh accounts for ≥80%, of which the particle size of -400 mesh accounts for more than 30%.

7. The method for extracting titanium by surface magnetization modification of full-grained ilmenite according to claim 5, characterized in that: In step 3, the heating temperature of the suspended heating furnace (5) is 700°C to 900°C, and the heating time is 1min to 10min; the temperature inside the oxidation reactor (7) is 600°C to 850°C, and the oxidation reaction time is 10min to 40min; the temperature inside the reduction reactor (9) is 450°C to 550°C, and the reduction reaction time is 5min to 20min.

8. The method for extracting titanium by surface magnetization modification of full-grained ilmenite according to claim 5, characterized in that: The reducing gas used in the reduction reaction in step 3 is H2 and CO produced by coal gasification or natural gas cracking, and the molar ratio of Fe2O3 in the oxidized solid material to the reducing gas is 0.5-1.0; the oxidizing gas is a mixed gas of oxygen and nitrogen, with an oxygen concentration of not less than 20%, or directly introduced into the air.

9. The method for extracting titanium by surface magnetization modification of full-grained ilmenite according to claim 5, characterized in that: In step 4, the solid material concentration in the water quenching stirring slurry tank (11) is 20% to 35%, the slurry temperature after cooling should be lower than 80°C, and the magnetic field strength of the primary magnetic separation and the secondary magnetic separation is 500Oe to 2000Oe; the slurry concentration in the stirred mill (13) is 30% to 45%, and the proportion of -325 mesh in the grinding product is ≥80%.

10. The method for extracting titanium by surface magnetization modification of full-grained ilmenite according to claim 5, characterized in that: The obtained titanium concentrate product has a TiO2 grade of ≥47%, a TiO2 recovery rate of ≥70%, and an iron concentrate grade of ≥65%.

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