Pre-enrichment method for low-grade fine-particle-size vanadium-titanium magnet tailings

Abstract

The invention discloses a pre-enrichment method for low-grade fine-particle-size vanadium-titanium magnet tailings, which comprises the following steps: by taking the low-grade fine-particle-size vanadium-titanium magnet tailings as a raw material, carrying out 100 [mu] m grading treatment on the raw material; carrying out high-intensity magnetic separation treatment on the minerals with the size fraction of-100 microns obtained through grading treatment to obtain final high-intensity magnetic concentrate; and finally, the selected final strong magnetic concentrate is concentrated, and pre-enriched concentrate is obtained. According to the method, the low-grade fine-particle-size vanadium-titanium magnet tailings can be effectively pre-enriched, high-grade pre-enriched concentrate and low-grade tailings are obtained, the purpose of recycling a large number of titanium resources from the low-grade fine-particle-size vanadium-titanium magnet tailings is achieved, loss of resources in the vanadium-titanium magnet tailings is greatly reduced, and the method has important economic value.

Description

Technical Field

[0001] The invention relates to the technical field of ore dressing, in particular to a method for pre-enriching low-grade fine-grained vanadium-titanium magnetite tailings. Background Art

[0002] Vanadium-titanium magnetite is a composite ore with multiple valuable elements such as iron, vanadium and titanium. my country has rich reserves of vanadium-titanium magnetite. In addition to iron, titanium and vanadium, it is often accompanied by rare elements such as chromium, cobalt, nickel, copper, gallium and scandium. Some deposits are also accompanied by platinum group elements or niobium, tantalum, zirconium, uranium, thorium, zinc and rare earth elements, which have high comprehensive utilization value. Among them, Panxi area is the largest vanadium-titanium magnetite base in my country.

[0003] In vanadium-titanium magnetite, vanadium is mainly present in the form of isomorphism in titanomagnetite, and titanium is mainly present in ilmenite. At present, the beneficiation technology of vanadium-titanium magnetite generally recovers titanomagnetite by weak magnetic first, and then recovers ilmenite from weak magnetic tailings. The main process is to process the mined vanadium-titanium magnetite ore through crushing-grinding process, and then select qualified iron concentrate and rough concentrate that meets the requirements through concentration, classification, magnetic separation, etc., and finally select qualified titanium concentrate from rough concentrate through flotation, gravity separation, etc.

[0004] At present, the titanium beneficiation process of vanadium-titanium magnetite mainly faces the following problems: (1) The grade of vanadium-titanium magnetite tailings is relatively high. With the in-depth development of vanadium-titanium magnetite mines in Panzhihua, the easy-to-develop extra-surface ores are becoming increasingly exhausted, and the development of titanium resources has shifted to intra-surface ores with low weathering degree and poor selectivity. Intra-surface ores have the characteristics of high hardness, low titanium grade, co-existence of multiple metals, and complex interweaving of multiple minerals. Therefore, the difficulty of mineral processing increases. Under the current process conditions, it is impossible to achieve a good mineral processing effect. Some useful minerals are discharged into the tailings, resulting in a TiO2 grade of some tailings higher than 3.5%. The titanium content of the tailings is relatively high, and the requirement of a TiO2 grade of less than 3.5% is not met. For this part of the ilmenite produced, it is necessary to obtain a qualified grade concentrate product through fine grinding and deep selection combined with multiple sorting methods. However, its production process is lengthy, and the cumulative metal loss of each sorting operation is high, making it difficult to obtain economic benefits. Therefore, most companies discharge this part of the tailings into the tailings pond, resulting in a waste of resources; (2) The particle size of the vanadium-titanium magnetite tailings is relatively fine. As the grade of ilmenite ore decreases, the particle size of useful minerals also becomes finer. In order to fully dissociate the ilmenite, the grinding fineness of the ore must be increased, resulting in a large amount of over-ground fine-grained ilmenite. The vertical ring pulsating high gradient magnetic separator commonly used now has a poor recovery effect on this part of fine-grained ilmenite. In addition, this part of fine-grained ilmenite has the characteristics of small mass, large specific surface area, and high surface energy. During the flotation process, the probability of collision and adhesion between minerals and bubbles is reduced, and gangue minerals are easy to float up with concentrate, and the consumption of flotation agents will also increase accordingly. Therefore, the beneficiation of fine-grained minerals is difficult and the beneficiation cost is high. This part of fine-grained minerals can only be discharged into the tailings pond and discarded, which seriously affects the improvement of titanium recovery rate; (3) The classification efficiency of fine-grained minerals is low. At present, the equipment used for grading is mainly divided into screen grading and inclined plate grading. In industry, the particle size of materials graded by screen can only reach 74μm. The grading efficiency of finer materials is very low due to the low opening rate of the screen, and it is difficult to use in industrial production. Inclined plate grading is used in both coarse and fine particle grading fields. Its principle mainly relies on the difference in the weight of the material itself to form underflow and overflow according to the difference in sedimentation rate. The fine particles are subject to very small differences in gravity and are affected by the morphology of the particles, so the particle size grading efficiency is low. The fine-grained vanadium-titanium magnetite tailings produced by this part of grinding are basically below 38μm. The particle size grading efficiency is low, and it is difficult to separate them for separate ore dressing.

[0005] In order to solve the above problems, domestic scientific researchers have carried out a series of research on the recovery of this part of fine-grained vanadium-titanium magnetite tailings, and carried out beneficiation by combining strong magnetic separation and centrifuge or suspension vibration beneficiation. However, when the process of combining strong magnetic separation and centrifuge is adopted, the centrifuge is intermittent beneficiation, and the production process seriously affects the production efficiency. In addition, the TiO2 grade of the vanadium-titanium magnetite tailings is only 3% to 5%, the beneficiation effect is general, and the final selected concentrate grade is low; and the suspension vibration beneficiation process belongs to the flow film beneficiation, which requires the material to be distributed as thinly as possible on the beneficiation and sorting surface. Therefore, on the one hand, the process needs to occupy a very large site, and on the other hand, how to evenly distribute the slurry to multiple suspension vibration beneficiations will directly affect the subsequent titanium concentrate indicators. It is difficult to obtain qualified concentrate products if the distribution is uneven, and it is difficult to ensure the effect of industrial implementation. Moreover, centrifuges and suspension vibration separation cannot accurately separate ilmenite and non-ilmenite according to the magnetic difference between them, but they separate according to the difference in specific gravity of the materials. The separation is affected by the particle size and morphology of the materials. For this part of vanadium-titanium magnetite tailings, the TiO2 content with a particle size of -18μm is 70% to 85%, and the separation effect is not ideal. It is easy to cause non-ilmenite to be selected into the concentrate, and ilmenite to be brought into the tailings, which will affect the subsequent flotation process.

[0006] The invention with application publication number CN104689904A discloses a method for selecting titanium concentrate from vanadium-titanium magnetite tailings. The vanadium-titanium magnetite tailings used are: TiO2 grade of 7% to 10%, and are enriched by strong magnetic separation, screening and the like. The final pre-enriched concentrate TiO2 grade is greater than 14%. The pre-enrichment adopts a process method of screening, grading, concentration and strong magnetic enrichment. However, the invention requires a high grade of the original ore, the pre-enrichment effect is general, and the TiO2 recovery rate is low, which is not conducive to the recycling of vanadium-titanium magnetite tailings. The invention with application publication number CN110038716A discloses a vanadium-titanium magnetite tailings recycling process, which adopts a gravity magnetic pulling concentrator for pre-enrichment. The vanadium-titanium magnetite tailings used are: TiO2 grade 5% to 8%, and the final pre-enriched concentrate with TiO2 grade of 12% to 15% and TiO2 recovery rate of 30% to 55% can be obtained. The pre-enrichment effect of this invention is good, but the grade of the tailings produced is still high, resulting in a waste of resources. The invention with authorization announcement number CN105944826A discloses a method for enriching ilmenite, which includes a method for pre-enriching fine-particle vanadium-titanium magnetite, and adopts hydrocyclones and flat ring magnetic separators for pre-enrichment and ore dressing. The vanadium-titanium magnetite tailings used have a TiO2 grade of 7% to 10%, and a pre-enriched concentrate with a TiO2 grade of 20% to 28% and a TiO2 recovery rate of 80% to 85% at -38μm can be obtained. The original ore particle size of the invention is relatively fine, and fine-particle vanadium-titanium magnetite can be effectively pre-enriched. However, the required original ore grade is relatively high, and low-grade minerals cannot be processed. In addition, the mineral grade is 38μm, and the grade efficiency is relatively low, which is not suitable for large-scale industrial production.

[0007] In recent years, mineral processing researchers have conducted more and more research on the recovery of low-grade, fine-particle vanadium-titanium magnetite tailings. For higher-grade (TiO2 grade higher than 5%) or coarser-particle vanadium-titanium magnetite tailings, there have been many studies on the effective recovery and utilization of vanadium-titanium magnetite tailings. However, for the low-grade (TiO2 grade lower than 5%) over-ground vanadium-titanium magnetite tailings produced in fine-particle low-grade grinding, no breakthrough progress has been made, and this part of vanadium-titanium magnetite tailings cannot be industrially recovered and utilized. Therefore, in order to ensure the recovery and utilization of this part of vanadium-titanium magnetite tailings, it is of great significance to develop a method that can effectively recover the titanium resources in the fine-particle vanadium-titanium magnetite tailings produced by this part of grinding, while ensuring the enrichment of high-grade TiO2 in vanadium-titanium magnetite tailings. Summary of the invention

[0008] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a method for pre-enrichment of low-grade fine-grained vanadium-titanium magnetite tailings.

[0009] The present invention provides a pre-enrichment method for low-grade fine-grained vanadium-titanium magnetite tailings, comprising the following steps: taking low-grade fine-grained vanadium-titanium magnetite tailings as raw materials, subjecting the raw materials to 100 μm classification treatment; subjecting the minerals with a particle size of -100 μm obtained by the classification treatment to strong magnetic separation treatment to obtain a final strong magnetic concentrate; and finally concentrating the selected final strong magnetic concentrate to obtain a pre-enriched concentrate.

[0010] The present invention has the following beneficial effects:

[0011] The present invention provides a method for pre-enrichment of low-grade fine-grained vanadium-titanium magnet tailings, comprising the following steps: taking low-grade fine-grained vanadium-titanium magnet tailings as raw materials, subjecting the raw materials to 100 μm classification treatment; subjecting the minerals of -100 μm particle size obtained by the classification treatment to strong magnetic separation treatment to obtain final strong magnetic concentrate; and finally concentrating the selected final strong magnetic concentrate to obtain a pre-enriched concentrate.

[0012] The above method provided by the present invention first classifies low-grade fine-grained vanadium-titanium magnet tailings to obtain -100μm fine-grained minerals that can be magnetically separated, and then the -100μm fine-grained minerals are subjected to strong magnetic separation to obtain final strong magnetic concentrates. The final strong magnetic concentrates can be concentrated to obtain pre-enriched concentrates, thereby achieving the purpose of recovering a large amount of titanium resources from low-grade fine-grained vanadium-titanium magnet tailings, greatly reducing the resource loss in the vanadium-titanium magnet tailings, and having important application value and economic value. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0014] Figure 1 This is a flow chart of the pre-enrichment method for low-grade, fine-grained vanadium-titanium magnetite tailings. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0016] The following is a specific description of a method for pre-enrichment of low-grade, fine-grained vanadium-titanium magnetite tailings provided in an embodiment of the present invention.

[0017] The embodiment of the present invention provides a pre-enrichment method for low-grade fine-grained vanadium-titanium magnet tailings, comprising the following steps: using low-grade fine-grained vanadium-titanium magnet tailings as raw material, subjecting the raw material to 100 μm grading treatment; then subjecting the -100 μm particle size mineral obtained by the grading treatment to strong magnetic separation treatment to obtain a final strong magnetic concentrate; finally, concentrating the selected final strong magnetic concentrate to obtain a pre-enriched concentrate.

[0018] The embodiment of the present invention provides a pre-enrichment method for low-grade fine-grained vanadium-titanium magnetite tailings, which is a method for pre-enrichment of low-grade fine-grained vanadium-titanium magnetite tailings that can effectively remove a large number of harmful components and has a high enrichment ratio. Specifically: it uses low-grade fine-grained vanadium-titanium magnetite tailings as raw materials. During the recovery process, the raw materials must first be graded. This is because: the inventors have found through experiments that it is difficult to obtain relatively high-grade titanium concentrate products for minerals with a particle size of +100μm, whether by gravity separation or magnetic separation. The experimental results also indirectly reflect the fact that this part of the titanium concentrate mainly exists in the form of conjoined bodies. Therefore, the -100μm obtained from the grading treatment is recovered, that is, the -100μm fine-grained ilmenite is mainly recovered by a strong magnetic method. If the magnetic field intensity is too low, it is easy to cause the loss of fine-grained ilmenite. When a high magnetic field intensity is used for concentration, the product quality and recovery rate of the fine-grained titanium concentrate can be improved. After that, it is concentrated to achieve the pre-enrichment of low-grade fine-grained vanadium-titanium magnetite, and at the same time, the flotation ore that can be directly floated, that is, the pre-enriched concentrate, can be obtained.

[0019] In an optional embodiment, the TiO2 grade of the low-grade fine-grained vanadium-titanium magnetite tailings is 3% to 5%, the TiO2 content of the -18 μm particle size is 70% to 85%, and the TiO2 content of the -10 μm particle size is 30% to 45%.

[0020] The embodiment of the present invention provides a pre-enrichment method for low-grade fine-particle vanadium-titanium magnetite tailings. The pre-enrichment method has low requirements on the grade of the original ore. Compared with other relevant documents, the original ore used in the present invention is vanadium-titanium magnetite tailings with a TiO2 grade of only 3% to 5%. The vanadium-titanium magnetite tailings are difficult to recycle and have low economic benefits for mineral processing. The method provided by the present invention can effectively recycle the vanadium-titanium magnetite tailings, reduce the waste of this part of titanium resources, and increase the utilization rate of titanium resources.

[0021] In an optional embodiment, the classification treatment includes: classifying the vanadium-titanium magnetite tailings using a classification cyclone.

[0022] In an optional embodiment, the strong magnetic separation treatment includes: using a vertical ring high gradient magnetic separator for strong magnetic tailing, and the process conditions include: feed concentration of 10-20%, 200-400 times / min, stroke of 30-40mm, and rod medium gap of 0.5-2.0mm. The vertical ring high gradient magnetic separator has the advantages of high efficiency, high precision, adaptability, ease of operation and economic applicability, and can accurately separate impurities of different magnetic properties, ensuring the quality and purity of the product.

[0023] In an optional embodiment, the process of the high intensity magnetic separation treatment is one coarse and two fine.

[0024] In an optional embodiment, the specific steps of the one rough and two fine operation are: subjecting the -100 μm particle size mineral to strong magnetic roughing at a magnetic field strength of 0.4T to 0.8T to obtain a roughing concentrate and a roughing tailing, and then subjecting the roughing concentrate to two strong magnetic concentrations at a magnetic field strength of 0.4T to 0.8T to obtain a strong magnetic concentrate as the final strong magnetic concentrate, and the tailings obtained by combining the roughing and concentration as the final tailings. Through the strong magnetic separation pre-enrichment process, a large number of harmful components can be effectively discarded, and at the same time, a useful final strong magnetic concentrate can be magnetically selected.

[0025] In an optional embodiment, the concentration treatment includes: using a concentration bucket for concentration, and the process conditions include: mixing the final strong magnetic concentrate selected by the strong magnetic separation with a flocculant and then concentrating to obtain a floatable flotation ore.

[0026] In an optional embodiment, the flocculant includes at least one of a cationic flocculant, an anionic flocculant, and a non-ionic flocculant.

[0027] In an optional embodiment, the flocculant is preferably anionic polyacrylamide, the molecular weight of the flocculant is 13 million to 17 million, and the amount of the flocculant is 10 g / t to 18 g / t.

[0028] The present invention provides a pre-enrichment method for low-grade fine-grained vanadium-titanium magnetite tailings. The final strong magnetic concentrate obtained by grading and strong magnetic separation of low-grade fine-grained vanadium-titanium magnetite tailings is added with a flocculant in an amount of 10g / t to 18g / t before entering the concentration equipment, and the overflow mineral concentration is reduced from 0.91% to 0.08%, which effectively improves the mineral sedimentation effect, increases the concentration efficiency, and also increases the final titanium resource recovery rate of the pre-enrichment in disguise. The above concentration treatment can increase the concentration of the final strong magnetic concentrate and obtain qualified floating ore.

[0029] In an optional embodiment, a qualified float ore with a TiO2 recovery rate of 25% to 45% and a pulp concentration of 20% to 30% is obtained through concentration treatment. The qualified float ore obtained through concentration treatment can be directly floated to recover the titanium resources therein.

[0030] In an optional embodiment, the TiO2 grade of the pre-enriched concentrate is 12% to 18%, and the TiO2 grade of the final tailings is less than 3.5%.

[0031] The present invention provides a pre-enrichment method for low-grade fine-grained vanadium-titanium magnetite tailings, which uses low-grade fine-grained vanadium-titanium magnetite tailings as raw materials, wherein the TiO2 content of the -18μm particle size in the low-grade fine-grained vanadium-titanium magnetite tailings is 70% to 85%, and the TiO2 content of the -10μm particle size is 30% to 45%. Through the pre-enrichment method provided by the present invention, the low-grade fine-grained vanadium-titanium magnetite tailings produced by grinding can be effectively enriched, and 25% to 45% of the titanium resources in the low-grade fine-grained vanadium-titanium magnetite tailings can be recovered, and the TiO2 grade of the final pre-enriched tailings is lower than 3.5%, which reduces the waste of this part of titanium resources and has important economic value.

[0032] The present invention will be further described below in conjunction with the embodiments.

[0033] Example 1

[0034] This example conducts a pre-enrichment test on Hongge ilmenite in Panxi area. Figure 1 , the pre-enrichment method comprises the following steps:

[0035] Step 1, classification by cyclone: ​​The low-grade fine-grained vanadium-titanium magnetite tailings are classified by 100 μm through a cyclone; the particle size of the magnetically separated tailings is shown in Table 1. The classification cyclone, model FX350-GX, has a processing capacity of 40 t / h, and the classification particle size is designed to be about 90% of the -75 μm content.

[0036] Table 1 Particle size composition and metal distribution of magnetic separation tailings

[0037]

[0038]

[0039] The particle sizes of the raw ore vary greatly, mainly concentrated in the -18μm and -10μm particle sizes, with yields of 40.57% and 24.53% respectively; from the perspective of TiO2 distribution rate, there is only 25.32% in the +18μm particle size and 74.68% in the -18μm particle size.

[0040] Step 2, strong magnetic separation: the -100μm mineral is subjected to strong magnetic roughing under a magnetic field strength of 0.8T to obtain roughing concentrate and roughing tailings, and then the roughing concentrate is subjected to two strong magnetic concentrations under a magnetic field strength of 0.6T. The obtained strong magnetic concentrate is the final strong magnetic concentrate, and the tailings obtained from the roughing and concentration are the final tailings. Among them, the equipment selected for the strong magnetic machine is a vertical ring high gradient magnetic separator. After experiments, the optimal process conditions of the strong magnetic machine are: feed concentration of 15%, stroke of 300 times / min, stroke of 35mm, and rod medium gap of 1.0mm.

[0041] Step 3, Concentration equipment concentration: The strong magnetic concentrate selected by strong magnetic separation enters the thickening bucket for concentration. The thickening bucket is a self-made thickening bucket with specifications of Before the material enters the thickening hopper, flocculant needs to be added at a rate of 14g / t. The flocculant is polyacrylamide produced by Aisen Flocculant Co., Ltd.

[0042] When the original ore contains 4.89% TiO2, after being classified by a cyclone and then concentrated through a one-rough and two-fine intense magnetic separation process, the final float ore with a TiO2 grade of 15.09%, a TiO2 recovery rate of 35.64%, and a slurry concentration of 21% can be obtained, and the final tailings with a TiO2 grade of 2.79% can be obtained.

[0043] Example 2

[0044] This example conducts a pre-enrichment test on Hongge ilmenite in Panxi area. Figure 1 , the pre-enrichment method comprises the following steps:

[0045] Step 1, classification by cyclone: ​​the low-grade fine-grained vanadium-titanium magnetite tailings are subjected to 100μm classification by cyclone; the classification cyclone, model FX350-GX, has a processing capacity of 40t / h, and the classification particle size is designed according to about 90% of the -75μm content.

[0046] Step 2, strong magnetic separation: the -100μm mineral is subjected to strong magnetic roughing under a magnetic field strength of 0.6T to obtain roughing concentrate and roughing tailings, and then the roughing concentrate is subjected to two strong magnetic concentrations under a magnetic field strength of 0.6T to obtain the strong magnetic concentrate as the final strong magnetic concentrate, and the tailings obtained from the roughing and concentration are the final tailings. Among them, the equipment selected for the strong magnetic machine is a vertical ring high gradient magnetic separator. After experiments, the optimal process conditions of the strong magnetic machine are: feed concentration of 15%, stroke of 300 times / min, stroke of 35mm, and rod medium gap of 1.0mm.

[0047] Step 3, Concentration equipment concentration: The strong magnetic concentrate selected by strong magnetic separation enters the thickening bucket for concentration. The thickening bucket is a self-made thickening bucket with specifications of Before the material enters the thickening hopper, flocculant needs to be added at a rate of 14g / t. The flocculant is polyacrylamide produced by Aisen Flocculant Co., Ltd.

[0048] When the original ore contains 4.89% TiO2, after being classified by a cyclone and then concentrated through a one-rough and two-fine intense magnetic separation process, the final float ore with a TiO2 grade of 15.52%, a TiO2 recovery rate of 30.64%, and a slurry concentration of 21% can be obtained, and the final tailings with a TiO2 grade of 2.95% can be obtained.

[0049] Example 3

[0050] This example conducts a pre-enrichment test on Hongge ilmenite in Panxi area. Figure 1 , the pre-enrichment method comprises the following steps:

[0051] Step 1, classification by cyclone: ​​the low-grade fine-grained vanadium-titanium magnetite tailings are subjected to 100μm classification by cyclone; the classification cyclone, model FX350-GX, has a processing capacity of 40t / h, and the classification particle size is designed according to about 90% of the -75μm content.

[0052] Step 2, strong magnetic separation: the -100μm mineral is subjected to strong magnetic roughing under a magnetic field strength of 0.4T to obtain roughing concentrate and roughing tailings, and then the roughing concentrate is subjected to two strong magnetic separations under a magnetic field strength of 0.6T. The obtained strong magnetic concentrate is the final strong magnetic concentrate, and the tailings obtained from the roughing and separation are the final tailings. Among them, the equipment selected for the strong magnetic machine is a vertical ring high gradient magnetic separator. After experiments, the optimal process conditions of the strong magnetic machine are: feed concentration of 15%, stroke of 300 times / min, stroke of 35mm, and rod medium gap of 1.0mm.

[0053] Step 3, Concentration equipment concentration: The strong magnetic concentrate selected by strong magnetic separation enters the thickening bucket for concentration. The thickening bucket is a self-made thickening bucket with specifications of Before the material enters the thickening hopper, flocculant needs to be added at a rate of 14g / t. The flocculant is polyacrylamide produced by Aisen Flocculant Co., Ltd.

[0054] When the original ore contains 4.89% TiO2, after being classified by a cyclone and then concentrated through a one-rough-two-fine intense magnetic separation process, the final titanium concentrate can contain 15.98% TiO2, a TiO2 recovery rate of 25.19%, and a slurry concentration of 21%. The final tailings can have a TiO2 grade of 3.38%.

[0055] Example 4

[0056] This example conducts a pre-enrichment test on Hongge ilmenite in Panxi area. Figure 1, the pre-enrichment method comprises the following steps:

[0057] Step 1, classification by cyclone: ​​the low-grade fine-grained vanadium-titanium magnetite tailings are subjected to 100μm classification by cyclone; the classification cyclone, model FX350-GX, has a processing capacity of 40t / h, and the classification particle size is designed according to about 90% of the -75μm content.

[0058] Step 2, strong magnetic separation: the -100μm mineral is subjected to strong magnetic roughing under a magnetic field strength of 0.8T to obtain roughing concentrate and roughing tailings, and then the roughing concentrate is subjected to two strong magnetic concentrations under a magnetic field strength of 0.8T to obtain the strong magnetic concentrate as the final strong magnetic concentrate, and the tailings obtained from the roughing and concentration are the final tailings. Among them, the equipment selected for the strong magnetic machine is a vertical ring high gradient magnetic separator. After experiments, the optimal process conditions of the strong magnetic machine are: feed concentration of 15%, stroke of 300 times / min, stroke of 35mm, and rod medium gap of 1.0mm.

[0059] Step 3, Concentration equipment concentration: The strong magnetic concentrate selected by strong magnetic separation enters the thickening bucket for concentration. The thickening bucket is a self-made thickening bucket with specifications of Before the material enters the thickening hopper, flocculant needs to be added at a rate of 14g / t. The flocculant is polyacrylamide produced by Aisen Flocculant Co., Ltd.

[0060] When the original ore contains 4.89% TiO2, after being classified by a cyclone and then concentrated through a one-rough and two-fine intense magnetic separation process, the final float ore with a TiO2 grade of 13.89%, a TiO2 recovery rate of 38.49%, and a slurry concentration of 21% can be obtained, and the final tailings with a TiO2 grade of 2.68% can be obtained.

[0061] Example 5

[0062] This example conducts a pre-enrichment test on Hongge ilmenite in Panxi area. Figure 1 , the pre-enrichment method comprises the following steps:

[0063] Step 1, classification by cyclone: ​​the low-grade fine-grained vanadium-titanium magnetite tailings are subjected to 100μm classification by cyclone; the classification cyclone, model FX350-GX, has a processing capacity of 40t / h, and the classification particle size is designed according to about 90% of the -75μm content.

[0064] Step 2, strong magnetic separation: the -100μm mineral is subjected to strong magnetic roughing under a magnetic field strength of 0.8T to obtain roughing concentrate and roughing tailings, and then the roughing concentrate is subjected to two strong magnetic separations under a magnetic field strength of 0.4T to obtain the strong magnetic concentrate as the final strong magnetic concentrate, and the tailings obtained from the roughing and separation are the final tailings. Among them, the equipment selected for the strong magnetic machine is a vertical ring high gradient magnetic separator. After experiments, the optimal process conditions of the strong magnetic machine are: feed concentration of 15%, stroke of 300 times / min, stroke of 35mm, and rod medium gap of 1.0mm.

[0065] Step 3, Concentration equipment concentration: The strong magnetic concentrate selected by strong magnetic separation enters the thickening bucket for concentration. The thickening bucket is a self-made thickening bucket with specifications of Before the material enters the thickening hopper, flocculant needs to be added at a rate of 14g / t. The flocculant is polyacrylamide produced by Aisen Flocculant Co., Ltd.

[0066] When the original ore contains 4.89% TiO2, after being classified by a cyclone and then concentrated through a rough and fine magnetic separation process, the final titanium concentrate can contain 16.29% TiO2, a TiO2 recovery rate of 30.19%, and a slurry concentration of 21%. The final tailings can have a TiO2 grade of 3.09%.

[0067] Example 6

[0068] The difference between this embodiment and embodiment 1 is that, after the cyclone classification treatment, this embodiment is concentrated after a coarse and fine magnetic separation process, and the rest is the same as embodiment 1, and finally a float ore with a TiO2 grade of 12.84%, a TiO2 recovery rate of 40.19%, and a slurry concentration of 21% is obtained, and a final tailings with a TiO2 grade of 2.98% can be obtained.

[0069] Example 7

[0070] The difference between this embodiment and embodiment 1 is that, after the cyclone classification treatment, this embodiment is concentrated after passing through a one-coarse and three-fine strong magnetic separation process, and the rest is the same as embodiment 1, and finally a float ore with a TiO2 grade of 16.27%, a TiO2 recovery rate of 27.53%, and a slurry concentration of 21% is obtained, and a final tailings with a TiO2 grade of 3.47% can be obtained.

[0071] Comparative Example 1

[0072] The enrichment method adopted in this comparative example is centrifuge gravity concentration enrichment. The minerals after cyclone classification are fed to the centrifugal concentrator for enrichment, wherein the feed concentration is 20%, the flushing water volume is 2.0 L / min, the drum speed is 680 r / min, and a one coarse and two fine process flow is adopted. The rest is the same as Example 1. Finally, a float ore with a TiO2 grade of 9.85%, a TiO2 recovery rate of 48.19%, and a slurry concentration of 37% is obtained, and a final tailings with a TiO2 grade of 3.87% can be obtained.

[0073] In this comparative example, a centrifugal concentrator was used to enrich the low-grade fine-grained vanadium-titanium magnetite tailings. Although the recovery rate was improved, the concentrate grade was not as good as that in Example 1, and it was difficult to enter the flotation system as a flotation ore. The main reason was that the tailings had a fine particle size distribution, uneven mineral distribution, and poor centrifugal effect.

[0074] Comparative Example 2

[0075] The difference between this comparative example and Example 1 is that the magnetic field strength of the strong magnetic roughing in this comparative example is 1.0T, and the rest is the same as Example 1. The grade of the obtained concentrate is low and it is difficult to directly float. The disadvantage is that the roughing magnetic field is too high, and a large amount of low-grade ore is selected into the concentrate, so the concentrate yield is increased, but the grade is reduced.

[0076] Comparative Example 3

[0077] The difference between this comparative example and Example 1 is that the magnetic field strength of the strong magnetic roughing separation in this comparative example is 0.2T, and the rest is the same as Example 1. The grade of the obtained concentrate is improved, but the yield is greatly reduced, the grade of the tailings is high, and a large amount of high-grade minerals enter the tailings. The reason is that the intensity of the roughing magnetic field is low, and it is difficult to effectively select part of the ilmenite, so the concentrate yield is reduced.

[0078] Comparative Example 4

[0079] The difference between this comparative example and Example 1 is that the strong magnetic field strength of this comparative example is 1.0T, and the rest are the same as Example 1. The obtained concentrate is not much different from that of Example 1. The main reason is that when the concentration magnetic field is 0.6T, ilmenite can be effectively selected. The increase in magnetic field strength has little effect on improving the mineral processing index, but will cause energy waste.

[0080] Comparative Example 5

[0081] The difference between this comparative example and Example 1 is that the magnetic field strength of the strong magnetic concentration in this comparative example is 0.2T, and the rest is the same as Example 1. The grade of the obtained concentrate is improved, but the yield is greatly reduced. The magnetic field strength is low, and it is difficult to effectively select part of the ilmenite, so the concentrate yield is reduced.

[0082] Comparative Example 6

[0083] The difference between this comparative example and Example 1 is that no flocculant is added in this comparative example, and the rest is the same as Example 1. The concentration of the obtained concentrate is low, and the mineral needs a lot of time to concentrate, which makes it difficult to directly carry out the subsequent flotation process, and the mineral processing efficiency is reduced.

[0084] It can be seen from the above experimental results that the pre-enrichment method of low-grade fine-grained vanadium-titanium magnetite tailings provided by the embodiment of the present invention has the following characteristics and advantages:

[0085] (1) The scheme provided by the present invention is suitable for low-grade vanadium-titanium magnetite. The present invention realizes the pre-enrichment of low-grade vanadium-titanium magnetite tailings, and the required pre-enrichment ore TiO2 grade is only 3% to 5%, and the final pre-enrichment tailings TiO2 grade is less than 3%. The required ore TiO2 grade of other documents is basically greater than 5%, and the tailings grade produced is relatively high, and the useful minerals cannot be effectively recycled.

[0086] (2) The scheme provided by the present invention is suitable for fine-grained vanadium-titanium magnetite. The present invention is suitable for vanadium-titanium magnetite tailings with a TiO2 content of 70% to 85% in the original ore particle size of -18μm and a TiO2 content of 30% to 45% in the original ore particle size of -10μm. Through the pre-enrichment method of the present invention, the finely ground vanadium-titanium magnetite tailings can be finally selected into qualified pre-enriched concentrates with a TiO2 grade of 12% to 18% and a TiO2 yield of 25% to 45%, effectively reducing the waste of titanium resources.

[0087] (3) The solution provided by the present invention is applicable to a wider range of particle sizes and has a better classification effect. The present invention is applicable to -100 μm minerals. Although there are still some titanium resources in the +18 μm particle size in the magnetic separation tailings, the main minerals are in the -18 μm particle size. Most other documents are used for +18 μm coarse particle size minerals, and -18 μm minerals cannot be effectively recovered. The present invention directly pre-enriches -100 μm minerals, effectively recycles and utilizes vanadium-titanium magnetite tailings, and reduces the TiO2 content in the final tailings. In addition, the classification particle size is controlled to 100 μm, the classification effect is good, the speed is fast, and it is more suitable for industrial production.

[0088] (4) The present invention is the first to apply a high-gradient high-intensity magnetic separator to the beneficiation of low-grade fine-grained vanadium-titanium magnetite tailings. Although other related patents have also been applied, they are all applied to normal-grained minerals with a TiO2 grade higher than 5%. The present invention can effectively improve the pre-enrichment effect of vanadium-titanium magnetite tailings, thereby improving the overall TiO2 recovery rate.

[0089] (5) In the present invention, a flocculant is added during the concentration process. The flocculant includes at least one of a cationic flocculant, an anionic flocculant and a non-ionic flocculant. Compared with cationic flocculants and non-ionic flocculants, anionic polyacrylamide is preferably used as a flocculant, which can effectively improve the mineral sedimentation effect, reduce the overflow mineral loss caused by concentration, improve the overall TiO2 recovery rate, and reduce the sedimentation time, which is more suitable for industrial production.

[0090] From the above, it can be seen that the embodiment of the present invention provides a pre-enrichment method for low-grade, fine-grained vanadium-titanium magnet tailings, including: after mineral classification treatment, a strong magnetic separation pre-enrichment process is adopted to achieve the goals of pre-enrichment concentrate TiO2 grade higher than 12%, tailings TiO2 grade less than 3.5% and TiO2 recovery rate higher than 25%. Compared with other pre-enrichment processes, compared with the centrifugal pre-enrichment process, the present invention has the advantage of good enrichment effect; compared with the superconducting pre-enrichment process, the present invention has the advantages of smaller industrial investment and more mature process; compared with the suspension vibration pre-enrichment process, the present invention has the advantages of large single-machine processing capacity and is more conducive to industrial production. Comprehensive analysis shows that a large amount of tailings can be discarded by the strong magnetic separation pre-enrichment process. Therefore, the strong magnetic separation pre-enrichment process is currently the most suitable pre-enrichment process for industrial production.

[0091] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for pre-enrichment of low-grade fine-grained vanadium-titanium magnetite tailings, characterized in that: The following steps are involved: Low-grade fine-grained vanadium-titanium magnetite tailings are used as raw materials. The raw materials are subjected to 100 μm classification treatment; the -100 μm particle size minerals obtained through the classification treatment are subjected to strong magnetic separation treatment to obtain a final strong magnetic concentrate; finally, the selected final strong magnetic concentrate is concentrated to obtain a pre-enriched concentrate.

2. The pre-enrichment method according to claim 1, characterized in that The TiO2 content of the low-grade fine-grained vanadium-titanium magnetite tailings is 3% to 5%, the TiO2 content of the -18μm particle size is 70% to 85%, and the TiO2 content of the -10μm particle size is 30% to 45%.

3. The pre-enrichment method according to claim 1, characterized in that The classification treatment includes: classifying the vanadium-titanium magnetite tailings using a classification cyclone.

4. The pre-enrichment method according to claim 1, characterized in that The strong magnetic separation treatment includes: using a vertical ring high gradient magnetic separator for strong magnetic tailings removal, and the process conditions include: feed concentration of 10-20%, flushing frequency of 200-400 times / min, stroke of 30-40mm, and rod medium gap of 0.5-2.0mm.

5. The pre-enrichment method according to claim 4, characterized in that: The process of high intensity magnetic separation is one coarse and two fine.

6. The pre-enrichment method according to claim 5, characterized in that The specific steps of the one roughing and two concentrating operation are: subjecting the -100μm particle size mineral to strong magnetic roughing separation at a magnetic field strength of 0.4T to 0.8T to obtain a roughing concentrate and a roughing tailings; then subjecting the roughing concentrate to two strong magnetic concentratings at a magnetic field strength of 0.4T to 0.8T to obtain a strong magnetic concentrate as the final strong magnetic concentrate, and the tailings obtained by combining the roughing and concentrating are used as the final tailings.

7. The pre-enrichment method according to claim 1, characterized in that: The concentration treatment includes: using a concentration bucket for concentration, and the process conditions include: mixing the final strong magnetic concentrate selected by the strong magnetic separation with a flocculant and then concentrating it to obtain a floatable flotation ore.

8. The pre-enrichment method according to claim 7, characterized in that The flocculant includes at least one of a cationic flocculant, an anionic flocculant and a non-ionic flocculant, preferably anionic polyacrylamide, more preferably the molecular weight of the flocculant is 13 million to 17 million, and the dosage of the flocculant is 10 g / t to 18 g / t.

9. The pre-enrichment method according to claim 8, characterized in that Through concentration treatment, a qualified float ore with a TiO2 recovery rate of 25% to 45% and a slurry concentration of 20% to 30% is obtained.

10. The pre-enrichment method according to claim 1, characterized in that: The TiO2 grade of the pre-enriched concentrate is 12% to 18%, and the TiO2 grade of the final tailings is less than 3.5%.

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