A method for recovering ilmenite by discarding tailings of vanadium-titanium magnetite

Abstract

The invention relates to a method for recovering ilmenite by discarding tailings of vanadium-titanium magnetite. The method comprises the following steps: raw material crushing and strong magnetic separation; strong magnetic separation tailings screening, oversize products entering tailings, undersize products and strong magnetic separation concentrate grinding and screening with a 1mm sieve, oversize products returning to grinding, undersize products weak magnetic separation, first weak magnetic separation tailings screening with 0.15mm and 0.074mm sieves; products with a size of 0.15mm and above being re-selected by a spiral chute, pre-enriched titanium concentrate grinding and weak magnetic separation, second weak magnetic separation tailings being strongly magnetically separated to obtain a first pre-enriched titanium coarse concentrate; products with a size of 0.074-0.15mm being re-selected by a shaking table to obtain a second pre-enriched titanium coarse concentrate; products with a size of 0.074mm and below being re-selected by a centrifuge to obtain a third pre-enriched titanium coarse concentrate; the first pre-enriched titanium coarse concentrate being classified by a cyclone, sand settling and the second pre-enriched titanium coarse concentrate being selected by a flotation machine, and overflow and the third pre-enriched titanium concentrate being selected by a flotation column to obtain a titanium concentrate. The present invention improves the comprehensive utilization rate of titanium resources.

Description

Technical Field

[0001] The present invention relates to the field of mineral processing, and more particularly to a method for recovering ilmenite by discarding tailings of vanadium-titanium magnetite. Background Art

[0002] With the continuous development and utilization of vanadium-titanium magnetite, high-quality iron ore resources are gradually becoming less and less, and the development and utilization of low-grade vanadium-titanium magnetite is receiving more and more attention. In the comprehensive utilization process of low-grade vanadium-titanium magnetite, it is necessary to discard its tailings. At present, the tailings discarding process is mostly dry magnetic separation tailings discarding, but the tailings particle size is large and the magnetic field intensity is low, resulting in the presence of some weakly magnetic ilmenite resources in the tailings. Technical research on this part of the ore resources can improve the overall utilization rate of vanadium-titanium magnetite resources. Summary of the Invention

[0003] The object of the present invention is to provide a method for recovering ilmenite from the tailings of vanadium-titanium magnetite, so as to improve the overall utilization rate of vanadium-titanium magnetite resources.

[0004] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0005] According to one aspect of the present invention, a method for recovering ilmenite from tailings of vanadium-titanium magnetite is provided, comprising the following steps:

[0006] Crushing the vanadium-titanium magnetite raw material to a particle size of less than 12 mm, and using the first high-intensity magnetic separator to perform high-intensity magnetic separation on the crushed product to obtain high-intensity magnetic separation concentrate and high-intensity magnetic separation tailings;

[0007] The obtained high-intensity magnetic separation tailings are screened and graded, the oversize products are transferred to the tailings, and the undersize products and the high-intensity magnetic separation concentrate are ground;

[0008] The grinding product is screened with a 1 mm sieve, the oversize product is returned to the grinding operation, and the undersize product is subjected to iron removal by a first weak magnetic separator to obtain a first weak magnetic separation iron-removed concentrate and a first weak magnetic separation iron-removed tailings. The first weak magnetic separation iron-removed concentrate is used as a raw material for iron separation;

[0009] The obtained first weak magnetic separation iron removal tailings are sieved using a 0.15mm sieve and a 0.074mm sieve to obtain products with a particle size of more than 0.15mm, products with a particle size between 0.074mm and 0.15mm, and products with a particle size of less than 0.074mm respectively;

[0010] The obtained product with a particle size of 0.15 mm or more is subjected to ilmenite pre-enrichment by spiral chute gravity separation to obtain pre-enriched titanium concentrate, and the pre-enriched titanium concentrate is ground, and the ground product is subjected to a second weak magnetic separator for iron removal to obtain a second weak magnetic separation iron-removed concentrate and a second weak magnetic separation iron-removed tailings, and the second weak magnetic separation iron-removed concentrate is used as an iron selection raw material, and the second weak magnetic separation iron-removed tailings are subjected to ilmenite pre-enrichment by a second strong magnetic separator to obtain a first pre-enriched titanium coarse concentrate;

[0011] The product with a particle size between 0.074 mm and 0.15 mm is subjected to ilmenite pre-enrichment by using a shaking table gravity separation to obtain a second pre-enriched titanium coarse concentrate;

[0012] The obtained product with a particle size of less than 0.074 mm is subjected to ilmenite pre-enrichment by a centrifuge to obtain a third pre-enriched titanium crude concentrate;

[0013] The first pre-enriched titanium concentrate is classified by a cyclone, the cyclone classification sand settling and the second pre-enriched titanium concentrate are selected by a flotation machine to obtain a titanium concentrate product, and the cyclone classification overflow and the third pre-enriched titanium concentrate are selected by a flotation column to obtain a titanium concentrate product.

[0014] In one embodiment of the present invention, the first high-intensity magnetic separator is an external-magnetic-inner-current high-intensity magnetic separator, the magnetic field strength of the external-magnetic-inner-current high-intensity magnetic separator is 7000-8000 Oe, the cylinder inclination angle is 6-8°, and the cylinder rotation speed is 10-15 r / min.

[0015] 3. The method for recovering ilmenite from vanadium-titanium magnetite tailings according to claim 2, wherein the sieve aperture range of the strong magnetic separation tailings screening and grading of the external magnetic inner flow strong magnetic separator is 0.25 mm.

[0016] In one embodiment of the present invention, the spiral chute gravity separation process for ilmenite pre-enrichment is a process of using a roughing separation, a second cleaning separation and a scavenging separation, the roughing feed concentration is 30-40wt%, the feed speed is 12-14m 3 / h; the concentration of the ore is 40-50wt%, and the feeding speed is 10-12m 3 / h; the scavenging feed concentration is 40-50wt%, and the feed speed is 12-14m 3 / h.

[0017] In one embodiment of the present invention, the grinding particle size of the pre-enriched titanium concentrate obtained by spiral chute gravity separation is below 0.074 mm, accounting for 70%-80%.

[0018] In one embodiment of the present invention, the magnetic field strength of the second high-intensity magnetic separator is 8000-9000 Oe.

[0019] In one embodiment of the present invention, the cyclone classification particle size is 0.074 mm, accounting for 90%.

[0020] In one embodiment of the present invention, the process for pre-enrichment of ilmenite by shaking table gravity separation is one roughing, two cleaning and one scavenging, and the parameters of roughing, cleaning and scavenging are a stroke of 10-15 mm, a stroke rate of 290-320 times / min, a bed transverse slope of 2-4°, and an ore concentration of 20-30 wt%.

[0021] In one embodiment of the present invention, the process of centrifuge gravity separation for ilmenite pre-enrichment is a roughing and a cleaning process, and the parameters of the roughing and cleaning are a rotation speed of 600-800 r / min and a feed concentration of 10-20 wt%.

[0022] In one embodiment of the present invention, the TiO2 grade in the vanadium-titanium magnetite raw material is 2.3%-2.8%, and the particle size of the vanadium-titanium magnetite raw material is below 50 mm.

[0023] By adopting the above technical solution, the present invention has the following advantages compared with the prior art:

[0024] The present invention can realize the recovery of titanium in the discarded tailings of vanadium-titanium magnetite, and can improve the comprehensive utilization rate of titanium resources and the output of titanium concentrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic flow chart of a method for recovering ilmenite from tailings of vanadium-titanium magnetite provided by the present invention is shown;

[0026] Figure 2 Shown Figure 1 Schematic diagram of the process of pre-enrichment of ilmenite using spiral chute gravity separation;

[0027] Figure 3 Shown Figure 1 The schematic diagram of the process of pre-enrichment of ilmenite by using shaking table gravity separation;

[0028] Figure 4 Shown Figure 1 Schematic diagram of the process for pre-enrichment of ilmenite using centrifuge gravity separation. DETAILED DESCRIPTION

[0029] It should be understood that the embodiments of the present invention shown in the exemplary embodiments are merely illustrative. Although only a few embodiments have been described in detail in the present invention, it is readily apparent to those skilled in the art that various modifications are feasible without departing substantially from the teachings of the subject matter of the present invention. Accordingly, all such modifications should be included within the scope of the present invention. Without departing from the gist of the present invention, other replacements, modifications, variations, and deletions may be made to the design, operating conditions, and parameters of the following exemplary embodiments.

[0030] like Figure 1 The present invention provides a method for recovering ilmenite from tailings of vanadium-titanium magnetite, comprising the following steps:

[0031] The vanadium-titanium magnetite raw material is crushed to a particle size of less than 12mm (-12mm), and the crushed product is subjected to strong magnetic separation using an external magnetic inner flow strong magnetic separator to obtain strong magnetic separation concentrate and strong magnetic separation tailings;

[0032] The obtained strong magnetic separation tailings are screened and graded, so that the oversize product (+) enters the tailings, and the undersize product (-) and the strong magnetic separation concentrate are ground using a rod mill (such as Figure 1 "One stage grinding" shown);

[0033] The grinding product is screened with a 1 mm sieve, the oversize product (+1 mm) is returned to the grinding operation, and the undersize product (-1 mm) is subjected to iron removal by a first weak magnetic separator to obtain a first weak magnetic separation iron-removed concentrate and a first weak magnetic separation iron-removed tailings. The first weak magnetic separation iron-removed concentrate is used as a raw material for iron separation;

[0034] The obtained first weak magnetic separation iron removal tailings are sieved using a 0.15mm sieve and a 0.074mm sieve to obtain products with a particle size of 0.15mm or more (+0.15mm), products with a particle size between 0.074mm and 0.15mm, and products with a particle size of less than 0.074mm (-0.074mm).

[0035] The product with a particle size of 0.15 mm or more (+0.15 mm) is subjected to pre-enrichment of ilmenite by spiral chute gravity separation to obtain pre-enriched titanium concentrate, and the pre-enriched titanium concentrate is ground by ball mill (such as Figure 1 The grinding product is subjected to iron removal by a second weak magnetic separator to obtain a second weak magnetic separation iron-removed concentrate and a second weak magnetic separation iron-removed tailings, the second weak magnetic separation iron-removed concentrate is used as an iron separation raw material, and the second weak magnetic separation iron-removed tailings are subjected to ilmenite pre-enrichment by a high-intensity magnetic separator to obtain a first pre-enriched titanium coarse concentrate;

[0036] The product with a particle size between 0.074 mm and 0.15 mm is subjected to ilmenite pre-enrichment by using a shaking table gravity separation to obtain a second pre-enriched titanium coarse concentrate;

[0037] The obtained product with a particle size of less than 0.074 mm (-0.074 mm) is pre-enriched with ilmenite using a centrifuge to obtain a third pre-enriched titanium coarse concentrate;

[0038] The first pre-enriched titanium concentrate is classified by a cyclone, the cyclone classification sand settling and the second pre-enriched titanium concentrate are selected by a flotation machine to obtain a titanium concentrate product, and the cyclone classification overflow and the third pre-enriched titanium concentrate are selected by a flotation column to obtain a titanium concentrate product.

[0039] Through the above technical solution of the present invention, the present invention can realize the recovery of titanium in the tailings of vanadium-titanium magnetite, and can improve the comprehensive utilization rate of titanium resources and the output of titanium concentrate.

[0040] In the above method, the magnetic field strength of the external magnetic inner current magnetic separator is 7000-8000 Oe, the cylinder inclination angle is 6-8 degrees, and the cylinder rotation speed is 10-15 r / min.

[0041] In the above method, the sieve aperture range of the strong magnetic separation tailings screening and grading of the external magnetic inner flow strong magnetic separator is 0.25mm.

[0042] In the above method, if Figure 2 As shown in the figure, the process of spiral chute gravity separation for ilmenite pre-enrichment is to use a roughing separation, a second cleaning separation and a scavenging separation, the roughing feed concentration is 30-40wt%, the feed speed is 12-14m 3 / h; the concentration of the ore is 40-50wt%, and the feeding speed is 10-12m 3 / h; the scavenging feed concentration is 40-50wt%, and the feed speed is 12-14m 3 / h.

[0043] In the above method, the grinding particle size of the pre-enriched titanium concentrate obtained by spiral chute gravity separation is below 0.074 mm, accounting for 70%-80%.

[0044] In the above method, the magnetic field strength of the strong magnetic separator used in the second weak magnetic iron removal of tailings is 8000-9000 Oe.

[0045] In the above method, the cyclone classification particle size is 0.074 mm, accounting for 90%.

[0046] In the above method, if Figure 3 As shown, the process of ilmenite pre-enrichment by shaking table gravity separation is one roughing separation, two cleaning separations and one scavenging separation. The parameters of roughing, cleaning and scavenging are a stroke of 10-15 mm, a stroke rate of 290-320 times / min, a bed transverse slope of 2-4°, and an ore concentration of 20-30 wt%.

[0047] In the above method, if Figure 4 As shown, the process of centrifuge gravity separation for ilmenite pre-enrichment is a roughing and a cleaning process, and the parameters of the roughing and cleaning are a rotation speed of 600-800 r / min and a feed concentration of 10-20 wt%.

[0048] In the above method, the TiO2 grade in the vanadium-titanium magnetite raw material is 2.3%-2.8%, and the particle size of the vanadium-titanium magnetite raw material is below 50 mm.

[0049] The above technical solution of the present invention is described in detail below through specific embodiments.

[0050] Example 1

[0051] A method for recovering ilmenite from vanadium-titanium magnetite tailings, comprising the following steps:

[0052] The vanadium-titanium magnetite raw material with a particle size of -40mm and a TiO2 grade of 2.63% was crushed to 12mm; the crushed product was magnetically separated by an external magnetic internal flow strong magnetic separator with a magnetic field strength of 7000Oe, a cylinder inclination angle of 6°, and a cylinder speed of 12r / min; the strong magnetic separation tailings were screened with a 0.25mm sieve, and the undersize product (-) and the strong magnetic separation concentrate were fed into the mill for first-stage grinding, and the oversize product (+) was the tailings. The first-stage grinding product was screened with a 1mm sieve, and the oversize product (+1mm) was returned to the mill. The ore is ground by machine, and the undersize product (-1mm) is subjected to weak magnetic de-ironing by a weak magnetic separator. The first weak magnetic de-ironing concentrate is used as the raw material for iron separation. The tailings from the first weak magnetic de-ironing are screened with 0.15mm and 0.074mm sieves to obtain three screening products of +0.15mm, 0.074mm-0.15mm, and -0.074mm. The +0.15mm product is pre-enriched with ilmenite by spiral chute gravity separation. The process is one roughing, two cleaning and one scavenging. The roughing feed concentration is 30% and the feed speed is 12m / s. 3 / h, concentration of ore feed 40%, feed speed 10m 3 / h, scavenging feed concentration 40%, feed speed 10m 3 / h; the spiral chute gravity separation concentrate is fed into the mill for grinding, and the grinding fineness of -0.074mm accounts for 75.63%. The grinding product is subjected to weak magnetic de-ironization by a weak magnetic separator. The second weak magnetic separation de-iron concentrate is used as the raw material for iron selection. The tailings of the second weak magnetic separation are separated by a slon-500 strong magnetic separator with a magnetic field strength of 8000Oe to obtain the first titanium coarse concentrate. The first titanium coarse concentrate is classified by a cyclone to obtain sedimentation and overflow; the 0.074mm-0.15 particle size product is pre-enriched by the Yunxi fine mud shaking table gravity separation of ilmenite. The process is one roughing, two cleaning and one scavenging. The roughing stroke is 12mm, the stroke is 300r / min, the slope is 2°, the feed concentration is 20%, the roughing stroke is 14mm, the stroke is 310r / min, the slope is 3°, The feed concentration is 25%, the scavenging stroke is 14mm, the stroke frequency is 310r / min, the slope is 2°, and the feed concentration is 25%, thereby obtaining the second titanium rough concentrate; the -0.074mm product is pre-enriched with ilmenite by centrifuge gravity separation, and the process is one roughing and one cleaning, the roughing speed is 600r / min, the feed concentration is 10%, the cleaning speed is 700r / min, and the feed concentration is 15%, thereby obtaining the third titanium rough concentrate; the cyclone classification overflow and the third titanium rough concentrate are selected by flotation column to obtain the first titanium concentrate; the cyclone classification sedimentation and the second titanium rough concentrate are selected by flotation column to obtain the second titanium concentrate; the first titanium concentrate and the second titanium concentrate are combined into a titanium concentrate product, and the titanium concentrate product has a TiO2 grade of 47.32% and a recovery rate of 31.17%.

[0053] Example 2

[0054] A method for recovering ilmenite from vanadium-titanium magnetite tailings, comprising the following steps:

[0055] The vanadium-titanium magnetite raw material with a particle size of -45mm and a TiO2 grade of 2.45% was crushed to 12mm; the crushed product was magnetically separated by an external magnetic internal flow strong magnetic separator with a magnetic field strength of 7500Oe, a cylinder inclination angle of 7°, and a cylinder speed of 12r / min; the strong magnetic separation tailings were screened with a 0.25mm sieve, and the undersize product (-) and the strong magnetic separation concentrate were fed into the mill for a first-stage grinding, and the oversize product (+) was the tailings. The first-stage grinding product was screened with a 1mm sieve, and the oversize product (+1mm) was returned to the mill. The ore is ground by machine, and the undersize product (-1mm) is subjected to weak magnetic de-ironing by a weak magnetic separator. The first weak magnetic de-ironing concentrate is used as the raw material for iron separation. The tailings from the first weak magnetic de-ironing are screened with 0.15mm and 0.074mm sieves to obtain three screening products of +0.15mm, 0.074mm-0.15mm, and -0.074mm. The +0.15mm product is pre-enriched with ilmenite by spiral chute gravity separation. The process is one roughing, two cleaning and one scavenging. The roughing feed concentration is 35% and the feed speed is 13m / s. 3 / h, concentration of ore feed 45%, feed speed 11m 3 / h, scavenging feed concentration 45%, feed speed 11m 3 / h; the spiral chute gravity separation concentrate is fed into the mill for grinding, with the grinding fineness of -0.074mm accounting for 78.51%. The grinding product is subjected to weak magnetic de-ironization by a weak magnetic separator. The second weak magnetic separation de-iron concentrate is used as the raw material for iron selection. The tailings of the second weak magnetic separation are separated by a slon-500 strong magnetic separator with a magnetic field strength of 8500Oe to obtain the first titanium coarse concentrate. The first titanium coarse concentrate is classified by a cyclone to obtain sedimentation and overflow; the 0.074mm-0.15 particle size product is pre-enriched by the Yunxi fine mud shaking table gravity separation of ilmenite. The process is one roughing, two cleaning and one scavenging. The roughing stroke is 13mm, the stroke is 310r / min, the slope is 3°, the feed concentration is 25%, the cleaning stroke is 13mm, the stroke is 320r / min, the slope is 4°, The feed concentration is 20%, the scavenging stroke is 14mm, the stroke frequency is 290r / min, the slope is 4°, and the feed concentration is 30%, thereby obtaining the second titanium rough concentrate; the -0.074mm product is pre-enriched with ilmenite by centrifuge gravity separation, and the process is one roughing and one cleaning, the roughing speed is 700r / min, the feed concentration is 15%, the cleaning speed is 750r / min, and the feed concentration is 15%, thereby obtaining the third titanium rough concentrate; the cyclone classification overflow and the third titanium rough concentrate are selected by flotation column to obtain the first titanium concentrate; the cyclone classification sedimentation and the second titanium rough concentrate are selected by flotation column to obtain the second titanium concentrate; the first titanium concentrate and the second titanium concentrate are combined into a titanium concentrate product, and the titanium concentrate product has a TiO2 grade of 47.12% and a recovery rate of 33.15%.

[0056] Example 3

[0057] A method for recovering ilmenite from vanadium-titanium magnetite tailings, comprising the following steps:

[0058] The vanadium-titanium magnetite raw material with a particle size of -50mm and a TiO2 grade of 2.57% was crushed to 12mm; the crushed product was magnetically separated by an external magnetic internal flow strong magnetic separator with a magnetic field strength of 8000Oe, a cylinder inclination angle of 8°, and a cylinder speed of 15r / min; the strong magnetic separation tailings were screened with a 0.25mm sieve, and the undersize product (-) and the strong magnetic separation concentrate were fed into the mill for a first-stage grinding, and the oversize product (+) was the tailings. The first-stage grinding product was screened with a 1mm sieve, and the oversize product (+1mm) was returned to the mill. Mechanical grinding; the undersize product (-1mm) is subjected to weak magnetic de-ironing by a weak magnetic separator. The first weak magnetic de-ironing concentrate is used as the raw material for iron separation. The first weak magnetic de-ironing tailings are screened with 0.15mm and 0.074mm sieves to obtain three screening products of +0.15mm, 0.074mm-0.15mm, and -0.074mm; the +0.15mm product is pre-enriched with ilmenite by spiral chute gravity separation. The process is one roughing, two cleaning and one scavenging. The roughing feed concentration is 40% and the feed speed is 12m 3 / h, concentration of ore feed 50%, feed speed 10m 3 / h, scavenging feed concentration 50%, feed speed 10m 3 / h; the spiral chute gravity separation concentrate is fed into the mill for grinding, with the grinding fineness of -0.074mm accounting for 72.32%. The grinding product is subjected to weak magnetic de-ironization by a weak magnetic separator. The second weak magnetic separation concentrate is used as the iron selection raw material. The second weak magnetic separation tailings are separated by a slon-500 strong magnetic separator with a magnetic field strength of 9000Oe to obtain the first titanium coarse concentrate. The first titanium coarse concentrate is classified by a cyclone to obtain sedimentation and overflow; the 0.074mm-0.15 particle size product is pre-enriched by the Yunxi fine mud shaking table gravity separation of ilmenite. The process is one roughing, two cleaning and one scavenging. The roughing stroke is 10mm, the stroke is 320r / min, the slope is 3°, the feed concentration is 30%, the cleaning stroke is 13mm, the stroke is 300r / min, the slope is 3°, The feed concentration is 25%, the scavenging stroke is 15mm, the stroke frequency is 290r / min, the slope is 4°, and the feed concentration is 20%, thereby obtaining a second titanium rough concentrate; the 0.074mm product is pre-enriched with ilmenite by centrifuge gravity separation, and the process is one roughing and one cleaning, the roughing speed is 750r / min, the feed concentration is 20%, the cleaning speed is 700r / min, and the feed concentration is 15%, thereby obtaining a third titanium rough concentrate; the cyclone classification overflow and the third titanium rough concentrate are selected by flotation column to obtain the first titanium concentrate; the cyclone classification sedimentation and the second titanium rough concentrate are selected by flotation column to obtain the second titanium concentrate; the first titanium concentrate and the second titanium concentrate are combined into a titanium concentrate product, and the titanium concentrate product has a TiO2 grade of 46.85% and a recovery rate of 34.22%.

[0059] It can be seen from the above Examples 1-3 that the present invention can realize the recovery of titanium from the tailings of vanadium-titanium magnetite, and can improve the comprehensive utilization rate of titanium resources and the output of titanium concentrate.

[0060] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of implementation of the present invention. If the present invention is modified or replaced with equivalents without departing from the spirit and scope of the present invention, it should be included in the scope of protection of the claims of the present invention.

Claims

1. A method for recovering ilmenite from vanadium-titanium magnetite tailings, characterized in that: The following steps are involved: Crushing the vanadium-titanium magnetite raw material to a particle size of less than 12 mm, and using the first high-intensity magnetic separator to perform high-intensity magnetic separation on the crushed product to obtain high-intensity magnetic separation concentrate and high-intensity magnetic separation tailings; The obtained high-intensity magnetic separation tailings are screened and graded, the oversize products are transferred to the tailings, and the undersize products and the high-intensity magnetic separation concentrate are ground; The grinding product is screened with a 1 mm sieve, the oversize product is returned to the grinding operation, and the undersize product is subjected to iron removal by a first weak magnetic separator to obtain a first weak magnetic separation iron-removed concentrate and a first weak magnetic separation iron-removed tailings. The first weak magnetic separation iron-removed concentrate is used as a raw material for iron separation; The obtained first weak magnetic separation iron removal tailings are sieved using a 0.15mm sieve and a 0.074mm sieve to obtain products with a particle size of more than 0.15mm, products with a particle size between 0.074mm and 0.15mm, and products with a particle size of less than 0.074mm respectively; The obtained product with a particle size of more than 0.15 mm is subjected to ilmenite pre-enrichment by spiral chute gravity separation to obtain pre-enriched titanium concentrate, and the pre-enriched titanium concentrate is ground, and the ground product is subjected to a second weak magnetic separator for iron removal to obtain a second weak magnetic separation iron-removed concentrate and a second weak magnetic separation iron-removed tailings, and the second weak magnetic separation iron-removed concentrate is used as an iron selection raw material, and the second weak magnetic separation iron-removed tailings are subjected to ilmenite pre-enrichment by a second strong magnetic separator to obtain a first pre-enriched titanium coarse concentrate; The product with a particle size between 0.074 mm and 0.15 mm is subjected to ilmenite pre-enrichment by using a shaking table gravity separation to obtain a second pre-enriched titanium coarse concentrate; The obtained product with a particle size of less than 0.074 mm is subjected to ilmenite pre-enrichment by a centrifuge to obtain a third pre-enriched titanium crude concentrate; The first pre-enriched titanium concentrate is classified by a cyclone, the cyclone classification sand settling and the second pre-enriched titanium concentrate are selected by a flotation machine to obtain a titanium concentrate product, and the cyclone classification overflow and the third pre-enriched titanium concentrate are selected by a flotation column to obtain a titanium concentrate product.

2. The method for recovering ilmenite from vanadium-titanium magnetite tailings according to claim 1, wherein: The first high-intensity magnetic separator is an external-magnetic-inner-current high-intensity magnetic separator, the magnetic field strength of the external-magnetic-inner-current high-intensity magnetic separator is 7000-8000 Oe, the cylinder inclination angle is 6-8°, and the cylinder rotation speed is 10-15 r / min.

3. The method for recovering ilmenite from vanadium-titanium magnetite tailings according to claim 2, wherein: The sieve aperture range of the strong magnetic separation tailings screening and grading of the external magnetic inner flow strong magnetic separator is 0.25mm.

4. The method for recovering ilmenite from vanadium-titanium magnetite tailings according to claim 1, wherein: The spiral chute gravity separation process for ilmenite pre-enrichment is to use a roughing, a cleaning and a scavenging. The roughing feed concentration is 30-40wt% and the feed speed is 12-14m 3 / h; the concentration of the ore is 40-50wt%, and the feeding speed is 10-12m 3 / h; the scavenging feed concentration is 40-50wt%, and the feed speed is 12-14m 3 / h.

5. The method for recovering ilmenite from tailings of vanadium-titanium magnetite according to claim 4, wherein: The grinding particle size of the pre-enriched titanium concentrate obtained by spiral chute gravity separation is below 0.074mm, accounting for 70%-80%.

6. The method for recovering ilmenite from tailings of vanadium-titanium magnetite according to claim 5, wherein: The magnetic field strength of the second strong magnetic separator is 8000-9000 Oe.

7. The method for recovering ilmenite from tailings of vanadium-titanium magnetite according to claim 1, wherein: The cyclone classification particle size is 0.074 mm, accounting for 90%.

8. The method for recovering ilmenite from tailings of vanadium-titanium magnetite according to claim 1, wherein: The process of pre-enrichment of ilmenite by shaking table gravity separation is one roughing, two cleaning and one scavenging. The parameters of roughing, cleaning and scavenging are stroke 10-15mm, stroke rate 290-320 times / min, bed surface transverse slope 2-4°, and feed concentration 20-30wt%.

9. The method for recovering ilmenite from tailings of vanadium-titanium magnetite according to claim 1, wherein: The process of centrifuge gravity separation for ilmenite pre-enrichment is a roughing and a cleaning process. The parameters of the roughing and cleaning processes are a rotation speed of 600-800 r / min and a feed concentration of 10-20 wt%.

10. The method for recovering ilmenite from tailings of vanadium-titanium magnetite according to claim 1, characterized in that: The TiO2 grade in the vanadium-titanium magnetite raw material is 2.3%-2.8%, and the particle size of the vanadium-titanium magnetite raw material is below 50 mm.

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