A chromium-reducing ore dressing method for ilmenite

Abstract

The present invention belongs to the technical field of ilmenite, and provides a chromium reduction beneficiation method for ilmenite, including positive flotation of desludging titanium coarse concentrate by flotation reagent; the desludging titanium coarse concentrate is obtained by slurrying chromium-containing ilmenite to a concentration of 45wt% to 70wt% and then washing and desludging; the flotation reagent includes: sodium fluoride or hydrofluoric acid as an adjusting agent 2, a compound agent of dodecyl diphosphate, diesel, sulfonate and pine alcohol as a collector, and the adjusting agent 2 is introduced under the condition of pH value of 1 to 2. The present invention combines the process of high-concentration washing and desludging positive flotation of ilmenite and a specific flotation reagent, greatly reduces the impurity content of chromite in the titanium concentrate, and also ensures a high recovery rate of titanium dioxide in the titanium concentrate, and the beneficiation method of the present invention does not undergo oxidative roasting, the investment cost and energy consumption are low, and it is easy to industrialize.

Description

Technical Field

[0001] The invention relates to the technical field of ilmenite, and in particular to a chromium-reducing beneficiation method for ilmenite. Background Art

[0002] Ilmenite is the main raw material for the production of chloride titanium dioxide, high-end special titanium dioxide, sponge titanium, metallic titanium or titanium materials. These products have very high requirements for the raw material ilmenite, especially the symbiotic impurity elements in the raw material. For example, if a trace amount of chromium enters the titanium dioxide, the whiteness of the titanium dioxide will be reduced. The chromium in ilmenite generally exists in the form of chromite. The presence of other impurity elements such as chromium will affect the quality of titanium dioxide products produced using ilmenite. Since the specific gravity and magnetic physical properties of ilmenite and chromite are similar, Haibin heavy sand mine adopts conventional gravity separation, magnetic separation or a combination of the two to recover, but this recovery method cannot separate the chromite from the ilmenite well. Therefore, it is difficult to obtain titanium concentrate containing qualified chromium, and the physical separation of chromite and ilmenite is extremely difficult.

[0003] In order to separate chromite from ilmenite, Chinese patent CN103316761B discloses a separation method containing ilmenite and chromite ore. The technology is mainly aimed at seashore heavy sand ore containing ilmenite and chromite. The ilmenite and chromite are enriched by ore preselection to obtain chromium-titanium medium ore. The chromium-titanium medium ore is oxidized and roasted to change the magnetic properties of ilmenite, increase the difference in the specific magnetic susceptibility of ilmenite and chromite, and then the chromite and ilmenite are separated by medium-strong magnetic separation to obtain chromite and titanium concentrate. Others use rotary kilns, fluidized beds or boiling furnaces to oxidize and roast the mixed coarse concentrates of ilmenite and chromite, and cool them naturally, which can enrich titanium well. Among them, the roasting process parameters are operating temperature 770°C, feed efficiency 3.0kg / h, and corresponding average residence time of 36 minutes. The minerals enriched by oxidation roasting are dry separated on a dry magnetic separator with a magnetic field of 0.3T to obtain titanium concentrate with a titanium grade of 47.94%, a recovery rate of 78.52% and a Cr2O3 content of 0.23%.

[0004] However, there is only one method for separating ilmenite and chromite in the prior art, namely, oxidative roasting-medium-strong magnetic separation. In essence, this method changes the specific magnetic susceptibility of chromite by high-temperature roasting, which is no longer in the scope of physical separation. In addition, this method has high energy consumption, high industrial investment and construction costs, and is not conducive to industrialization. Moreover, due to the limitations of this method, it is extremely difficult to further reduce the chromium content in titanium concentrate and the cost will increase significantly.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The present invention provides a chromium reduction beneficiation method for ilmenite, which is used to solve the defect that chromium in titanium concentrate is difficult to separate by physical separation in the prior art, thereby effectively reducing the chromium content in the titanium concentrate and ensuring a high titanium dioxide recovery rate in the titanium concentrate.

[0007] The present invention provides a chromium reduction beneficiation method for ilmenite, comprising: performing positive flotation on deslimed titanium coarse concentrate by means of a flotation agent;

[0008] The deslimed titanium crude concentrate is obtained by slurrying the chromium-containing ilmenite to a concentration of 45wt% to 70wt% and then washing and desliming.

[0009] Preferably, the deslimed titanium crude concentrate is obtained by slurrying the chromium-containing ilmenite to a concentration of 50wt% to 60wt% and then washing and desliming;

[0010] The panning and desludging process includes at least one panning and desludging process; after the panning and desludging process, fine mud and desludged titanium coarse concentrate are obtained.

[0011] The flotation reagent includes: sodium fluoride or hydrofluoric acid as a regulator 2, dodecyl diphosphate as a collector, diesel, sulfonate and pinene alcohol compound reagent;

[0012] The adjusting agent 2 is introduced under the condition of pH value of 1-2.

[0013] According to a chromium-reducing ilmenite beneficiation method provided by the present invention, in the chromium-containing ilmenite, the titanium-containing mineral is mainly ilmenite, and the chromium-containing mineral is chromite;

[0014] Preferably, the titanium dioxide grade of the chromium-containing ilmenite is 40wt% to 42wt%, and the chromium grade is 1.7wt% to 2.5wt%.

[0015] The chromium-containing ilmenite is a medium-grade ilmenite obtained through chute gravity separation, desludging, weak magnetic separation and strong magnetic separation.

[0016] According to a chromium-reducing ilmenite beneficiation method provided by the present invention, the deslimed titanium crude concentrate is obtained by slurrying the chromium-containing ilmenite, and then washing and desliming with a spiral ore washer.

[0017] According to a chromium reduction beneficiation method for ilmenite provided by the present invention, the direct flotation is as follows: firstly, the deslimed titanium coarse concentrate is slurried to control the slurry concentration to be 15wt% to 30wt%, and after being mixed with a flotation agent, the chromium tailings and titanium concentrate are obtained by direct flotation chromium reduction operation.

[0018] The chromium tailings obtained by the direct flotation chromium reduction operation and the fine mud obtained after washing and desludging are combined into the total tailings; the titanium concentrate is the final titanium concentrate with a chromium content of less than 0.1wt%.

[0019] According to a chromium reduction beneficiation method for ilmenite provided by the present invention, the positive flotation chromium reduction operation includes at least 2 roughing operations, at least 2 cleaning operations and at least 1 scavenging operation.

[0020] According to a chromium reduction beneficiation method for ilmenite provided by the present invention, the flotation reagents for the first roughing operation are: 1kg / t to 12kg / t of adjusting agent 1, 100g / t to 500g / t of adjusting agent 2, and 100g / t to 1000g / t of collecting agent;

[0021] The adjusting agent 1 is phosphoric acid or sulfuric acid.

[0022] The first roughing process of the present invention is to mix the deslimed titanium rough concentrate with the positive flotation chromium reduction agent, for example, by stirring, preferably in two stirring devices in sequence; the specific operation is: the deslimed titanium rough concentrate enters the first stirring device, and the adjusting agent 1 and the adjusting agent 2 are added for stirring, and the mixing time is ≤5min. After mixing, it enters the second stirring device, and then the collector is added for stirring, and the mixing time is ≤3min.

[0023] The first roughing operation in the present invention obtains a titanium rough concentrate 1 and a chromium tailing 1.

[0024] According to the ilmenite chromium reduction beneficiation method provided by the present invention, the flotation reagent of the second roughing operation is: 50g / t to 500g / t of collector.

[0025] Generally, the amount of reagent added in the last roughing should be lower than that in the previous one, and should be selected according to the actual situation. In addition, when the second or more roughing is performed, the type of reagent added can be selected according to the actual situation. For example, the second roughing is generally only adding collector, but it is not limited to this.

[0026] When the present invention performs multiple roughing (≥2 times) or scavenging, the reagent mixing in the second and subsequent roughing or scavenging processes is performed in the flotation machine.

[0027] The second roughing operation in the present invention is to perform positive flotation on the chromium tailings 1 obtained in the first roughing operation to obtain titanium rough concentrate 2 and chromium tailings 2.

[0028] According to the ilmenite chromium reduction beneficiation method provided by the present invention, the flotation reagent of the first scavenging operation is: 50g / t to 200g / t of collector.

[0029] The first scavenging operation in the present invention is to perform positive flotation on the chromium tailings 2 obtained in the second roughing operation to obtain the middlings 2 and the chromium tailings 3; wherein the middlings 2 are returned to the last roughing operation.

[0030] According to a chromium reduction beneficiation method for ilmenite provided by the present invention, the flotation reagents for the first beneficiation operation are: 0.1kg / t to 2.0kg / t of the adjusting agent 1 and 50g / t to 200g / t of the adjusting agent 2.

[0031] The first concentration operation in the present invention is to perform a concentration operation on the titanium rough concentrate obtained by combining the titanium rough concentrates obtained in each roughing operation to obtain the titanium rough concentrate and the middling ore 1; wherein the middling ore 1 is returned to the last roughing operation.

[0032] According to a chromium reduction beneficiation method for ilmenite provided by the present invention, the last concentration operation is blank concentration without adding any flotation reagent.

[0033] The second concentration operation in the present invention is to concentrate the titanium rough concentrate obtained in the first concentration operation to obtain titanium concentrate and middling ore 3; wherein the middling ore 3 is returned to the previous concentration operation, and the titanium concentrate is the final titanium concentrate with a chromium content of less than 0.1wt%.

[0034] The present invention provides a chromium reduction beneficiation method for ilmenite, such as Figure 1 As shown in the figure, by first performing the high-concentration washing and desludging process, the friction between the minerals and the mineral surfaces is significantly increased due to the high-concentration stirring working environment, which improves the efficiency of fine mud separation from the mineral surface and creates a better mineral surface modification environment for the subsequent positive flotation chromium reduction operation. Reducing the covering effect of fine mud on the mineral surface and promoting the directional hydrophobic-hydrophilic regulation of flotation reagents is not only beneficial to improving the separation efficiency of ilmenite and chromite, but also beneficial to reducing the consumption of flotation reagents. Furthermore, in the positive flotation process, on the one hand, by introducing fluoride ions in a strongly acidic environment (especially phosphoric acid or sulfuric acid as the adjuster 1), chromite is selectively suppressed, thereby further cleaning the surface of ilmenite and chromite is achieved to expose the clean surface. On the other hand, a compound reagent of dodecyl diphosphate, diesel, sulfonate and pineneol is used as a collector. In particular, dodecyl diphosphate in the compound reagent has a good collection ability for ilmenite, and sulfonate helps the dispersibility of dodecyl diphosphate in aqueous solution. Diesel and pineneol can further enhance the collection of coarser and finer particles of ilmenite. The present invention combines the process of high-concentration washing and desludging-positive flotation of ilmenite and specific flotation reagents, which greatly reduces the impurity content of chromite in titanium concentrate and ensures a high recovery rate of titanium dioxide in titanium concentrate, specifically: the recovery rate of titanium dioxide in titanium concentrate is 70% to 85%, the chromium grade is not higher than 0.10wt%, and the titanium dioxide grade is 48wt% to 50wt%.

[0035] Moreover, the mineral separation method of the present invention is a physical separation method that can efficiently separate ilmenite and chromite without oxidative roasting, has low investment cost and energy consumption, and is easy to industrialize. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 This is one of the schematic flow diagrams of the mineral processing method provided by the present invention;

[0038] Figure 2 This is the second schematic flow diagram of the mineral processing method provided by the present invention. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] If no specific techniques or conditions are specified in the examples, the techniques or conditions described in the literature in the field or the product instructions are used. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased through regular channels.

[0041] Combine the following Figure 2 The present invention describes the ilmenite chromium reduction beneficiation method.

[0042] Example 1

[0043] A chromium reduction beneficiation method for ilmenite, the specific process is:

[0044] Raw material preparation: Chromium-bearing ilmenite is a medium-grade chromium-bearing ilmenite in Sichuan. The titanium-bearing minerals in the ore are mainly ilmenite, the chromium-bearing minerals are chromite, and it also contains some quartz, calcite, limonite, etc. The chromium-bearing ilmenite obtained by spiral chute desludging-weak magnetic separation-strong magnetic separation has a titanium dioxide grade of 41.37wt% and a chromium grade of 1.78wt%.

[0045] like Figure 2 As shown, the method comprises the following steps:

[0046] (1) slurrying the chromium-containing titanium iron ore and controlling the slurry concentration to 55 wt% for washing, and then desludging through a spiral ore washer to obtain fine mud and desludified titanium coarse concentrate;

[0047] (2) The deslimed titanium rough concentrate obtained in step (1) is first slurried to control the pulp concentration to 27wt% and then mixed with flotation reagents sulfuric acid, sodium fluoride and BK437 (a compound reagent of dodecyl diphosphate, diesel, sulfonate and pinene alcohol, purchased from Beikuang Chemical Technology (Cangzhou) Co., Ltd.) in two stirring devices in sequence, and the mixed pulp is subjected to positive flotation chromium reduction roughing operation 1 to obtain chromium tailings 1 and titanium rough concentrate 1; the chromium tailings 1 are mixed with the flotation reagent BK437 in the middle box of the flotation machine, and chromium tailings 2 and titanium rough concentrate 2 are obtained after roughing 2; the chromium tailings 2 are mixed with the flotation reagent BK437 in the middle box of the flotation machine, and chromium tailings 3 and middlings 2 are obtained after scavenging; and the middlings 2 are returned to the roughing operation 2;

[0048] (3) The titanium rough concentrate 1 and the titanium rough concentrate 2 obtained in step (2) are combined into titanium rough concentrate 3, the titanium rough concentrate 3 is mixed with flotation reagents sulfuric acid and sodium fluoride in the middle box of the flotation machine, and the titanium rough concentrate 4 and the middling ore 1 are obtained through the selection operation 1, and the middling ore 1 is returned to the roughing operation 2;

[0049] (4) the titanium crude concentrate 4 obtained in step (3) is subjected to a concentration 2 operation (blank concentration) to obtain a titanium concentrate and a middling ore 3, and the middling ore 3 is returned to the concentration 1 operation;

[0050] (5) The fine mud obtained in step (1) and the chromium tailings 3 obtained in step (2) are combined into the total tailings, and the titanium concentrate obtained in step (4) is the final titanium concentrate.

[0051] Wherein, in step (2), the amount of sulfuric acid added in the roughing 1 process is 10 kg / t, the amount of sodium fluoride added is 300 g / t, and the amount of BK437 added is 800 g / t; the amount of BK437 added in the roughing 2 process is 400 g / t; and the amount of BK437 added in the scavenging process is 100 g / t;

[0052] In step (3), the amount of sulfuric acid added during the selection process 1 is 1 kg / t, and the amount of sodium fluoride added is 100 g / t;

[0053] The titanium dioxide grade of the titanium concentrate finally obtained was 49.52wt%, the chromium grade was 0.095wt%, and the titanium dioxide recovery rate of the titanium concentrate was 80.65%.

[0054] Example 2

[0055] This embodiment provides a chromium reduction beneficiation method for ilmenite, and the specific process is as follows:

[0056] Raw material preparation: The chromium-containing ilmenite is a medium-grade chromium-containing ilmenite in Hebei. The titanium-containing minerals in the ore are mainly ilmenite, and contain a small amount of rutile. The chromium-containing minerals are chromite, and also contain some quartz, feldspar, hematite, limonite, etc. The chromium-containing ilmenite obtained by weak magnetic separation and strong magnetic separation has a titanium dioxide grade of 42.68wt% and a chromium grade of 2.35wt%.

[0057] The method comprises the following steps:

[0058] (1) slurrying the chromium-containing titanium iron ore to control the slurry concentration to be 60wt% and high-concentration washing, and then desludging by a spiral ore washer, and desludging is performed twice to obtain fine mud 1, fine mud 2 and desludging titanium coarse concentrate;

[0059] (2) the deslimed titanium rough concentrate obtained in step (1) is first slurried to control the slurry concentration to 27wt% and then mixed with flotation reagents sulfuric acid, sodium fluoride and BK437 (a compound reagent of dodecyl diphosphate, diesel, sulfonate and pinene alcohol) in two stirring devices in sequence, and the mixed slurry is subjected to positive flotation chromium reduction roughing operation 1 to obtain chromium tailings 1 and titanium rough concentrate 1; the chromium tailings 1 are mixed with the flotation reagent BK437 in the middle box of the flotation machine, and chromium tailings 2 and titanium rough concentrate 2 are obtained after roughing 2; the chromium tailings 2 are mixed with the flotation reagent BK437 in the middle box of the flotation machine, and chromium tailings 3 and titanium rough concentrate 3 are obtained after roughing 3; the chromium tailings 3 are mixed with the flotation reagent BK437 in the middle box of the flotation machine, and chromium tailings 4 and middlings 2 are obtained after scavenging; and the middlings 2 are returned to the roughing operation 3;

[0060] (3) the titanium rough concentrate 1, titanium rough concentrate 2 and titanium rough concentrate 3 obtained in step (2) are combined into titanium rough concentrate 4, the titanium rough concentrate 4 is mixed with flotation reagents sulfuric acid and sodium fluoride in the middle box of the flotation machine, and the titanium rough concentrate 5 and the middling ore 1 are obtained through the selection operation 1, and the middling ore 1 is returned to the roughing operation 3;

[0061] (4) The titanium crude concentrate 5 obtained in step (3) is subjected to a concentration 2 operation (blank concentration) to obtain a titanium concentrate and a middling ore 3, and the middling ore 3 is returned to the concentration 1 operation.

[0062] (5) The fine mud 1 and fine mud 2 obtained in step (1) and the chromium tailings 4 obtained in step (2) are combined into the total tailings, and the titanium concentrate obtained in step (4) is the final titanium concentrate.

[0063] Wherein, in step (2), the amount of sulfuric acid added in the roughing 1 process is 11 kg / t, the amount of sodium fluoride added is 400 g / t, and the amount of BK437 added is 750 g / t; the amount of BK437 added in the roughing 2 process is 400 g / t; the amount of BK437 added in the roughing 3 process is 200 g / t; the amount of BK437 added in the scavenging process is 150 g / t;

[0064] In step (3), the amount of sulfuric acid added during the selection process 1 is 1.5 kg / t, and the amount of sodium fluoride added is 200 g / t;

[0065] The titanium dioxide grade of the titanium concentrate finally obtained was 48.12wt%, the chromium grade was 0.097wt%, and the titanium dioxide recovery rate of the titanium concentrate was 78.96%.

[0066] Example 3

[0067] A chromium reduction beneficiation method for ilmenite, the specific process is:

[0068] Raw material preparation: The chromium-containing ilmenite is a medium-grade chromium-containing ilmenite in Mozambique, Africa, which belongs to the seashore placer. The titanium-containing minerals in the ore are mainly ilmenite, and contain a small amount of rutile. The chromium-containing minerals are chromite, and also contain some quartz, mica, limonite, etc. The chromium-containing ilmenite obtained by spiral chute gravity separation, desliming, weak magnetic separation, and strong magnetic separation has a titanium dioxide grade of 40.15wt% and a chromium grade of 1.89wt%.

[0069] The method comprises the following steps:

[0070] (1) slurrying the chromium-containing titanium iron ore to control the slurry concentration to be 60wt% and high-concentration washing, and then desludging by a spiral ore washer, and desludging is performed twice to obtain fine mud 1, fine mud 2 and desludging titanium coarse concentrate;

[0071] (2) the deslimed titanium rough concentrate obtained in step (1) is first slurried to control the pulp concentration to 27wt% and then mixed with flotation reagents sulfuric acid, sodium fluoride and BK437 (a compound reagent of dodecyl diphosphate, diesel, sulfonate and pinene alcohol) in two stirring devices in sequence, and the mixed pulp is subjected to positive flotation chromium reduction roughing operation 1 to obtain chromium tailings 1 and titanium rough concentrate 1; the chromium tailings 1 are mixed with the flotation reagent BK437 in the middle box of the flotation machine, and chromium tailings 2 and titanium rough concentrate 2 are obtained after roughing 2; the chromium tailings 2 are mixed with the flotation reagent BK437 in the middle box of the flotation machine, and chromium tailings 3 and middlings 2 are obtained after scavenging; and the middlings 2 are returned to the roughing operation 2;

[0072] (3) The titanium rough concentrate 1 and the titanium rough concentrate 2 obtained in step (2) are combined into titanium rough concentrate 3, the titanium rough concentrate 3 is mixed with flotation reagents sulfuric acid and sodium fluoride in the middle box of the flotation machine, and the titanium rough concentrate 4 and the middling ore 1 are obtained through the selection operation 1, and the middling ore 1 is returned to the roughing operation 2;

[0073] (4) the titanium rough concentrate 4 obtained in step (3) is subjected to a beneficiation operation 2 to obtain a titanium rough concentrate 5 and a middling ore 3, and the middling ore 3 is returned to the beneficiation operation 1;

[0074] (5) The titanium crude concentrate 5 obtained in step (4) is subjected to a concentration 3 operation (blank concentration) to obtain a titanium concentrate and a middling ore 4, and the middling ore 4 is returned to the concentration 2 operation;

[0075] (6) The fine mud 1 and fine mud 2 obtained in step (1) and the chromium tailings 3 obtained in step (2) are combined into the total tailings, and the titanium concentrate obtained in step (5) is the final titanium concentrate.

[0076] In step (2), the amount of sulfuric acid added in the roughing 1 process is 8 kg / t, the amount of sodium fluoride added is 400 g / t, and the amount of BK437 added is 850 g / t; the amount of BK437 added in the roughing 2 process is 400 g / t; the amount of BK437 added in the scavenging process is 100 g / t

[0077] In step (3) the amount of sulfuric acid added during the selection process 1 is 1.8 kg / t, and the amount of sodium fluoride added is 150 g / t;

[0078] In step (4), the amount of sulfuric acid added during the selection 2 is 1.0 kg / t, and the amount of sodium fluoride added is 100 g / t;

[0079] The titanium dioxide grade of the titanium concentrate finally obtained was 48.25wt%, the chromium grade was 0.084wt%, and the titanium dioxide recovery rate of the titanium concentrate was 75.67%.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A chromium reduction beneficiation method for ilmenite, characterized in that: include: The deslimed titanium coarse concentrate is positively floated by flotation reagents; The deslimed titanium crude concentrate is obtained by slurrying the chromium-containing ilmenite to a concentration of 45wt% to 70wt% and then washing and desliming; The flotation reagent includes: sodium fluoride or hydrofluoric acid as a regulator 2, dodecyl diphosphate as a collector, diesel, sulfonate and pinene alcohol compound reagent; The adjusting agent 2 is introduced under the condition of pH value of 1-2.

2. The ilmenite chromium reduction beneficiation method according to claim 1, characterized in that: In the chromium-containing ilmenite, the titanium-containing mineral is mainly ilmenite, and the chromium-containing mineral is chromite.

3. The chromium reduction beneficiation method for ilmenite according to claim 2, characterized in that: The titanium dioxide grade of the chromium-containing ilmenite is 40wt%-42wt%, and the chromium grade is 1.7wt%-2.5wt%.

4. The ilmenite beneficiation method for reducing chromium content according to claim 1, characterized in that: The deslimed titanium crude concentrate is obtained by slurrying the chromium-containing ilmenite, and then washing and desliming with a spiral ore washer.

5. The ilmenite beneficiation method for reducing chromium according to claim 1, characterized in that: The direct flotation is as follows: firstly, the deslimed titanium coarse concentrate is slurried to control the slurry concentration to be 15wt%-30wt%, and then mixed with flotation reagents, and then subjected to direct flotation chromium reduction operation to obtain chromium tailings and titanium concentrate.

6. The ilmenite beneficiation method for reducing chromium content according to claim 5, characterized in that: The direct flotation chromium reduction operation includes at least 2 roughing operations, at least 2 cleaning operations and at least 1 scavenging operation.

7. The ilmenite beneficiation method for reducing chromium content according to claim 6, characterized in that: The flotation reagents for the first roughing operation are: 1kg / t~12kg / t of adjusting agent 1, 100g / t~500g / t of adjusting agent 2, and 100g / t~1000g / t of collecting agent; The adjusting agent 1 is phosphoric acid or sulfuric acid.

8. The ilmenite beneficiation method for reducing chromium content according to claim 6, characterized in that: The flotation reagent for the second roughing operation is: 50g / t~500g / t of collector.

9. The ilmenite beneficiation method for reducing chromium content according to claim 6, characterized in that: The flotation reagent for the first sweep operation is: 50g / t~200g / t of collector.

10. The ilmenite beneficiation method for reducing chromium content according to claim 6, characterized in that: The flotation reagents for the first concentration operation are: 0.1kg / t~2.0kg / t of adjusting agent 1, 50g / t~200g / t of adjusting agent 2; The adjusting agent 1 is phosphoric acid or sulfuric acid.

11. The ilmenite beneficiation method for reducing chromium content according to claim 6, characterized in that: The last selection job is a blank selection.

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