Magnetic-gravity combined iron separation process for vanadium titano-magnetite

Abstract

The invention discloses a magnetic-gravity combined iron separation process for vanadium titano-magnetite, and belongs to the technical field of ore separation. In order to realize high-TFe-grade recovery of iron ore concentrate in the vanadium titano-magnetite, the invention provides a magnetic-gravity combined iron separation process for the vanadium titano-magnetite, which comprises the following steps: first-stage ore grinding, first-stage magnetic separation, second-stage ore grinding, second-stage magnetic separation, first-stage RC gravity separation, third-stage ore grinding, third-stage magnetic separation and second-stage RC gravity separation to obtain the iron ore concentrate. According to the method, the magnetism and specific gravity differences of the titanomagnetite and other minerals are fully utilized, the titanomagnetite and gangue minerals are dissociated through first-stage and second-stage ore grinding and first-stage and second-stage magnetic separation, concentrate with the high titanomagnetite content is obtained, then first-stage RC reselection operation is adopted, the titanomagnetite and the gangue minerals with the similar specific magnetization coefficients are separated, and the content of the titanomagnetite is increased. And finally, through three-stage ore grinding, three-stage magnetic separation and two-stage RC, the minerals with the magnetism difference and the specific gravity difference from the titanomagnetite are further separated, and iron ore concentrate with the high TFe grade is obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of ore dressing, and in particular relates to a magnetic-gravity combined iron separation process for vanadium-titanium magnetite. Background Art

[0002] Vanadium-titanium magnetite is a composite mineral resource with multiple valuable components such as iron, vanadium, and titanium. It contains valuable components such as iron, titanium, sulfur, and cobalt. It is recognized as an important strategic resource by countries around the world and has extremely high comprehensive utilization value. my country has rich reserves of vanadium-titanium magnetite resources, up to 30 billion tons, mainly distributed in Panxi, Sichuan, Chengde, Hebei, Hanzhong, Shaanxi, and Daixian, Shanxi.

[0003] The iron in vanadium-titanium magnetite is mainly found in the useful mineral titanomagnetite, which has strong magnetism. At present, the titanomagnetite in vanadium-titanium magnetite is mainly recovered by single magnetic separation to produce iron concentrate. Due to the low content of valuable components, complex mineral composition and mineral embedding relationship of vanadium-titanium magnetite, it is difficult to recover the titanomagnetite, and the TFe grade of the iron concentrate produced is low, which is difficult to reflect the properties of vanadium-titanium magnetite.

[0004] Therefore, there is an urgent need for an iron separation process that can recover titanium magnetite from vanadium-titanium magnetite and produce iron concentrate with high TFe grade, so as to improve the utilization value of vanadium-titanium magnetite in Panzhihua area.

[0005] CN117427752A discloses a process for ball milling and tailings disposal of vanadium-titanium magnetite, comprising the following steps: S1, conveying the crude product of vanadium-titanium magnetite from a silo to a first ball mill through a feeding assembly for ball milling, conveying the product after ball milling to a first magnetic separator for a first magnetic separation, the concentrate after magnetic separation enters a first hydrocyclone for hydraulic classification, the tailings after magnetic separation are subjected to tailings disposal, the concentrate after hydraulic classification enters a first rough magnetic separation, the tailings after hydraulic classification enter a first reflux channel and return to a ball mill at one end, the concentrate and tailings obtained after a first rough magnetic separation, the tailings are disposed of, and the concentrate after a first rough magnetic separation enters a second hydrocyclone for hydraulic classification; S2, the concentrate entering the second hydrocyclone in step S1 is subjected to hydraulic classification; The coarse ore after hydraulic classification in the hydrocyclone enters the second-stage ball mill, and then enters the second reflux channel to return to the second hydrocyclone for hydraulic classification after a first-stage fine magnetic separation in the second magnetic separator; the concentrate after hydraulic classification in the second hydrocyclone is subjected to high-frequency fine screening, and the screened product after the high-frequency fine screening enters the dewatering magnetic separator, and the coarse ore after magnetic separation enters the second-stage ball mill again, the tailings after magnetic separation are discarded, and the underscreen product after high-frequency fine screening enters the second-stage fine magnetic separation, the tailings obtained in the second-stage fine magnetic separation are discarded, and the concentrate obtained in the second-stage fine magnetic separation enters the third-stage fine magnetic separation; S3, the tailings obtained after the third-stage fine magnetic separation in the above step S2 are discarded, and the concentrate obtained in the third-stage fine magnetic separation enters the filter, and the concentrate is recovered after filtration by the filter, and the water is returned.

[0006] CN117983397A discloses a method for selecting high-quality iron concentrate from ultra-low-grade vanadium-titanium magnetite, comprising the following steps: S1, screening the crushed ore through a linear screen: the material on the linear screen enters a first-stage ball mill, and the first-stage ball mill discharge returns to the linear screen to realize a first-stage closed-circuit grinding; the material with qualified particle size under the linear screen passes through a first-stage magnetic separation: the first-stage magnetic separation concentrate enters a second-stage cyclone, and the first-stage magnetic separation tailings are discharged to a titanium selection workshop as a titanium selection raw material; S2, classifying the first-stage magnetic separation concentrate through the second-stage cyclone: ​​the sand settling of the second-stage cyclone enters the second-stage ball mill, and the second-stage ball mill discharge returns to the second-stage cyclone to realize closed-circuit grinding; the overflow of the second-stage cyclone enters the second-stage magnetic separation: the second-stage magnetic separation concentrate enters a high-frequency stacked screen, and the second-stage magnetic separation tailings are discharged to a titanium selection workshop as a titanium selection raw material. workshop; S3, the two-stage magnetic separation concentrate is graded through high-frequency stacked screens, wherein the material on the high-frequency stacked screens enters the three-stage cyclone for classification: the sediment of the three-stage cyclone enters the three-stage ball mill for regrinding, and the three-stage ball mill discharge returns to the three-stage cyclone for classification; the overflow of the three-stage cyclone returns to the high-frequency stacked screen to realize closed-circuit grinding; the high-frequency stacked screen enters the three-stage magnetic separation: the three-stage magnetic separation concentrate enters the high-frequency harmonic magnetic separator, and the three-stage magnetic separation tailings are discharged to the titanium selection workshop as a titanium selection raw material; S4, the three-stage magnetic separation concentrate is selected and upgraded through the high-frequency harmonic magnetic separator: the high-frequency harmonic magnetic separation concentrate enters the grade hoist, and the high-frequency harmonic magnetic separation tailings are discharged to the titanium selection workshop as a titanium selection raw material; S5, the concentrate coming out of the grade hoist is iron concentrate; the tailings coming out of the grade hoist are discharged to the titanium selection workshop as a titanium selection raw material.

[0007] CN116099649A discloses a method for combined magnetic and gravity separation of vanadium-titanium magnetite: the vanadium-titanium magnetite ore is subjected to first-stage grinding magnetic separation, second-stage grinding magnetic separation and third-stage grinding magnetic separation, and then separated to obtain a tertiary magnetic separation concentrate, and the tertiary magnetic separation concentrate is subjected to elution magnetic separation by an elutriation magnetic separator to obtain a high-grade iron concentrate; the first-stage grinding magnetic separation is to subject the vanadium-titanium magnetite ore to first-stage magnetic separation for selective separation after first-stage grinding and classification, so as to obtain a primary tailing and a primary magnetic separation concentrate; the second-stage grinding magnetic separation is to subject the primary magnetic separation concentrate to second-stage grinding and classification, so as to obtain a secondary tailing and a secondary magnetic separation concentrate; the third-stage grinding magnetic separation is to subject the secondary magnetic separation concentrate to third-stage grinding and classification, so as to obtain a tertiary tailing and a tertiary magnetic separation concentrate; the elutriation magnetic separation is to subject the tertiary magnetic separation concentrate to an elutriation magnetic separator, and to magnetic separation under the condition of a field strength of 1000GS, so as to obtain a high-grade iron concentrate.

[0008] The above methods all use magnetic separation to separate vanadium-titanium magnetite, and do not separate based on the density of the minerals. It is difficult to separate the low-density gangue minerals of vanadium-titanium magnetite, resulting in the iron concentrate inevitably containing about 10% of low-density gangue minerals, which is not conducive to subsequent use. Therefore, it is necessary to develop a new process for recovering iron concentrate from vanadium-titanium magnetite. Summary of the invention

[0009] The purpose of the present invention is to provide a process for recovering iron concentrate from vanadium-titanium magnetite to produce iron concentrate with high TFe grade. The method has the characteristics of producing iron concentrate with high TFe grade, stable production process and no pollution, thereby improving the utilization value of vanadium-titanium magnetite.

[0010] To achieve the above object, the present invention provides a magnetic-gravity combined iron separation process for vanadium-titanium magnetite, which comprises the following steps:

[0011] A. Grinding the vanadium-titanium magnetite in the first stage to obtain a first-stage grinding product, wherein the fineness of the first-stage grinding product is controlled at -0.074 mm, accounting for 30-50%;

[0012] B. subjecting the first-stage grinding product obtained in step A to the first-stage magnetic separation to obtain a first-stage magnetic separation coarse iron concentrate (the tailings obtained from the first-stage magnetic separation are directly discarded);

[0013] C. After demagnetizing the primary magnetic separation crude iron concentrate obtained in step B, a second stage of grinding is performed to obtain a second stage grinding product, wherein the fineness of the second stage grinding product is controlled at -0.074 mm, accounting for 55-80%;

[0014] D. subjecting the second-stage grinding product obtained in step C to a second-stage magnetic separation to obtain a second-stage magnetic separation crude iron concentrate (the tailings obtained from the second-stage magnetic separation are directly discarded);

[0015] E. After demagnetizing the two-stage magnetic separation rough iron concentrate obtained in step D, the first stage RC gravity separation is carried out, the feed concentration of the first stage RC gravity separation is controlled at 30-50%, the feed speed is controlled at 1.0-10 L / min, the inclined plate spacing is controlled at 1.0-5.0 mm, the fluidized water speed of the feed is controlled at 0.1-0.4 L / min, and the bottom flow obtained is a first stage RC gravity separation rough iron concentrate (the overflow obtained from the first stage RC gravity separation is directly discarded as tailings);

[0016] F. The first stage RC gravity separation iron coarse concentrate obtained in step E is subjected to the third stage grinding to obtain a three-stage grinding product, wherein the fineness of the three-stage grinding product is controlled at -0.043 mm, accounting for 85-90%;

[0017] G. The three-stage grinding product obtained in step F is subjected to the third-stage magnetic separation to obtain the three-stage magnetic separation coarse iron concentrate (the tailings obtained from the third-stage magnetic separation are directly discarded);

[0018] H. After demagnetizing the three-stage magnetic separation coarse iron concentrate obtained in step G, the second stage RC gravity separation is carried out, the feed concentration of the second stage RC gravity separation is controlled at 30-50%, the feed speed is controlled at 1.0-10 L / min, the inclined plate spacing in the second stage RC gravity separation operation is controlled at 1.0-5.0 mm, the fluidized water speed of the feed is controlled at 0.1-0.4 L / min, and the bottom flow obtained is the final iron concentrate (the overflow obtained from the second stage RC gravity separation is directly discarded as tailings).

[0019] Wherein, in the above-mentioned magnetic-gravity combined iron separation process of vanadium-titanium magnetite, in step A, the particle size of the vanadium-titanium magnetite is -12mm≥90%.

[0020] Among them, in the above-mentioned magnetic-gravity combined iron separation process of vanadium-titanium magnetite, in step B, the magnetic field intensity of the first magnetic separation is controlled at 1000-5000Oe.

[0021] Among them, in the above-mentioned magnetic-gravity combined iron separation process of vanadium-titanium magnetite, in step D, the magnetic field intensity of the second magnetic separation is controlled at 1500-5000Oe.

[0022] Among them, in the above-mentioned magnetic-gravity combined iron separation process of vanadium-titanium magnetite, in step G, the magnetic field strength of the third magnetic separation is controlled at 3000-5000Oe.

[0023] The beneficial effects of the present invention are:

[0024] The present invention separates the useful mineral titanium magnetite in the vanadium titanium magnetite from gangue minerals such as pyroxene and feldspar with coarse embedded particle sizes through one-stage and two-stage grinding operations, and separates the titanium magnetite with strong magnetism from the weakly magnetic ilmenite and non-magnetic gangue minerals after one-stage and two-stage magnetic separation operations, so as to obtain a coarse concentrate with a high content of titanium magnetite, realizes the separation of titanium magnetite and gangue minerals at a coarse particle size, and has the advantages of low grinding processing capacity and low energy consumption.

[0025] The mineral particles in the concentrate obtained by the two-stage magnetic separation operation are mainly single titanium magnetite ore particles, gangue mineral and titanium magnetite intergrowth particles, ilmenite and a small amount of feldspar, pyroxene monomers, etc. Titanium magnetite particles and intergrowth particles of titanium magnetite and gangue minerals have similar specific magnetic susceptibility coefficients and are difficult to be further separated by magnetic separation. Therefore, the present invention adopts a one-stage RC gravity separation operation, mainly using the difference in specific gravity of mineral particles for separation. In the water flow that overcomes gravity and moves upward, the specific gravity of titanium magnetite and intergrowth particles, feldspar, and pyroxene monomer particles is relatively small, and overflows with the water flow, while the titanium magnetite particles settle downward due to their large specific gravity. Therefore, the grade of the iron concentrate TFe obtained by the sedimentation of the one-stage RC operation is further improved.

[0026] The iron concentrate obtained from the first-stage RC gravity separation operation contains gangue minerals and ilmenite with finer particle sizes. It is fed to the third-stage grinding operation and the grinding fineness is controlled to be relatively high so that the useful mineral titanomagnetite is fully dissociated from the gangue minerals and ilmenite with finer particle sizes. The third-stage grinding product is fed to the third-stage magnetic separation operation and the second-stage RC operation to further separate the minerals with different magnetic properties and specific gravity from the titanomagnetite. The TFe grade of the obtained iron concentrate is further improved, and an iron concentrate with a high TFe grade is obtained.

[0027] The present invention adopts a magnetic-gravity combined process and three-stage grinding to gradually reduce the grinding amount, which is more conducive to improving the ore dressing effect and reducing energy consumption. It fully utilizes the magnetic properties and specific gravity differences between titanium magnetite and other minerals, so that the titanium magnetite and gangue minerals in the vanadium-titanium magnetite are fully separated, Fe is well enriched, and high-TFe grade iron concentrate is produced. The process is a purely physical process and will not pollute the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The present invention is a process flow chart of the combined magnetic-gravity iron separation of vanadium-titanium magnetite. DETAILED DESCRIPTION

[0029] The present invention is further described in detail below by way of examples, but the protection scope of the present invention is not limited to the scope of the examples.

[0030] Example 1

[0031] The vanadium-titanium magnetite in this embodiment comes from a place in Xichang, and its petrological composition is shown in Table 1.

[0032] Table 1 Chemical composition analysis of a vanadium-titanium magnetite ore in Xichang

[0033] element TFe <![CDATA[TiO2]]> MgO <![CDATA[SiO2]]> <![CDATA[Al2O3]]> CaO grade / % 28.51 10.32 2.77 6.01 4.88 4.02

[0034] (1) Feed the -12mm vanadium-titanium magnetite into a first-stage grinding operation for grinding, and the fineness of the grinding product is controlled at -0.074mm, accounting for 35%;

[0035] (2) feeding the first grinding product of step (1) into a first magnetic separation operation for separation, wherein the magnetic field strength of the first magnetic separation is controlled at 3000 Oe, and the tailings obtained by separation are directly discarded;

[0036] (3) After demagnetization, the coarse iron concentrate obtained in the first magnetic separation operation in step (2) is fed into the second grinding operation for grinding, and the fineness of the ground product is controlled at -0.074 mm, accounting for 65%;

[0037] (4) The product of the second-stage grinding operation is fed into the second-stage magnetic separation operation for separation, and the magnetic field strength is controlled at 3000Oe. The tailings obtained by separation are directly discarded;

[0038] (5) After demagnetization, the second-stage crude iron concentrate obtained in step (4) is fed into a first-stage RC gravity separation operation for separation, wherein the feed concentration is controlled at 35%, the feed speed is controlled at 3 L / min, the inclined plate spacing in the first-stage RC gravity separation operation is controlled at 3 mm, the feed fluidizing water speed is controlled at 0.3 L / min, and the overflow obtained from separation is directly discarded as tailings;

[0039] (6) feeding the first stage RC gravity separation iron concentrate obtained in step (5) into a tower mill for grinding, controlling the grinding fineness to -0.043 mm, accounting for 85%;

[0040] (7) The product obtained from the tower grinding in step (6) is fed into a three-stage magnetic separation operation, and the magnetic field intensity of the three-stage magnetic separation is controlled at 3500Oe, and the tailings obtained by separation are directly discarded;

[0041] (8) After demagnetizing the three-stage magnetic separation crude iron concentrate obtained in step (7), the feed concentration is controlled at 35%, the feed rate is controlled at 3 L / min, the inclined plate spacing in the second-stage RC gravity separation operation is controlled at 3 mm, the fluidized water feed rate is controlled at 0.3 L / min, the overflow obtained from the separation is directly discarded as tailings, and the underflow obtained from the separation is used as the final concentrate.

[0042] (9) According to the above steps, the final product index can be obtained as shown in Table 2, which combines the first-stage magnetic separation tailings, the second-stage magnetic separation tailings, the first-stage RC gravity separation tailings and the second-stage RC gravity separation tailings.

[0043] Table 2 Implementation results of a vanadium-titanium magnetite mine in Xichang

[0044] Product Name Yield / % TFe grade / % TFe recovery rate / % Iron Concentrate 34.99 61.21 75.12 Tailings 65.01 10.91 24.88 Ore 100.00 28.51 100.00

[0045] Example 2

[0046] The vanadium-titanium magnetite in this embodiment comes from a place in Panzhihua, and its floral composition is shown in Table 3.

[0047] Table 3 Chemical composition analysis of a vanadium-titanium magnetite in Panzhihua

[0048] element TFe <![CDATA[TiO2]]> MgO <![CDATA[SiO2]]> <![CDATA[Al2O3]]> CaO grade / % 27.33 11.02 3.75 5.89 5.01 3.66

[0049] (1) Feed the -12mm vanadium-titanium magnetite into a first-stage grinding operation for grinding, and the fineness of the grinding product is controlled at -0.074mm, accounting for 40%;

[0050] (2) The first grinding product of step (1) is fed into a first magnetic separation operation for separation, the magnetic field strength of the first magnetic separation is controlled at 3500 Oe, and the tailings obtained by separation are directly discarded;

[0051] (3) After demagnetizing the primary magnetic separation crude iron concentrate obtained in step (2), the concentrate is fed into the secondary grinding process for grinding, and the fineness of the ground product is controlled to be -0.074 mm, accounting for 70%;

[0052] (4) The product of the second-stage grinding operation is fed into the second-stage magnetic separation operation for separation. The magnetic field strength is controlled at 3500Oe, and the tailings obtained from separation are directly discarded;

[0053] (5) After demagnetization, the second-stage crude iron concentrate obtained in step (4) is fed into a first-stage RC gravity separation operation for separation, wherein the feed concentration is controlled at 35%, the feed speed is controlled at 3 L / min, the inclined plate spacing in the first-stage RC gravity separation operation is controlled at 3 mm, the fluidized water feed speed is controlled at 0.4 L / min, and the overflow obtained from separation is directly discarded as tailings;

[0054] (6) feeding the first stage RC gravity separation iron concentrate obtained in step (5) into a tower mill for grinding, controlling the grinding fineness to -0.043 mm, accounting for 90%;

[0055] (7) The product obtained from the tower grinding in step (6) is fed into a three-stage magnetic separation operation, and the magnetic field intensity of the three-stage magnetic separation is controlled at 3500Oe, and the tailings obtained by separation are directly discarded;

[0056] (8) After demagnetizing the three-stage magnetic separation crude iron concentrate obtained in step (7), the feed concentration is controlled at 35%, the feed rate is controlled at 3 L / min, the inclined plate spacing in the second-stage RC gravity separation operation is controlled at 3 mm, the fluidized water feed rate is controlled at 0.4 L / min, the overflow obtained from the separation is directly discarded as tailings, and the underflow obtained from the separation is used as the final concentrate;

[0057] (9) According to the above steps, the final product index can be obtained as shown in Table 4, which combines the first-stage magnetic separation tailings, the second-stage magnetic separation tailings, the first-stage RC gravity separation tailings and the second-stage RC gravity separation tailings.

[0058] Table 4 Implementation results of a vanadium-titanium magnetite mine in Xichang

[0059] Product Name Yield / % TFe grade / % TFe recovery rate / % Iron Concentrate 34.82 60.11 76.58 Tailings 65.18 9.82 23.42 Ore 100.00 27.33 100.00

Claims

1. A combined magnetic-gravity iron separation process for vanadium-titanium magnetite, characterized in that: The following steps are involved: A. Grinding the vanadium-titanium magnetite in the first stage to obtain a first-stage grinding product, wherein the fineness of the first-stage grinding product is controlled at -0.074 mm, accounting for 30-50%; B. subjecting the first-stage grinding product obtained in step A to a first-stage magnetic separation to obtain a first-stage magnetically separated coarse iron concentrate; C. After demagnetizing the primary magnetic separation crude iron concentrate obtained in step B, a second stage of grinding is performed to obtain a second stage grinding product, wherein the fineness of the second stage grinding product is controlled at -0.074 mm, accounting for 55-80%; D. subjecting the second-stage grinding product obtained in step C to a second-stage magnetic separation to obtain a second-stage magnetic separation crude iron ore concentrate; E. After demagnetizing the two-stage magnetic separation rough iron concentrate obtained in step D, the first stage RC gravity separation is carried out, the feed concentration of the first stage RC gravity separation is controlled at 30-50%, the feed speed is controlled at 1.0-10 L / min, the inclined plate spacing is controlled at 1.0-5.0 mm, the fluidized water feed speed is controlled at 0.1-0.4 L / min, and the bottom flow obtained is the first stage RC gravity separation rough iron concentrate; F. The first stage RC gravity separation iron coarse concentrate obtained in step E is subjected to the third stage grinding to obtain a three-stage grinding product, wherein the fineness of the three-stage grinding product is controlled at -0.043 mm, accounting for 85-90%; G. subjecting the three-stage grinding product obtained in step F to a third-stage magnetic separation to obtain a three-stage magnetic separation crude iron ore concentrate; H. After demagnetizing the three-stage magnetic separation coarse iron concentrate obtained in step G, the second-stage RC gravity separation is carried out. The feed concentration of the second-stage RC gravity separation is controlled at 30-50%, the feed speed is controlled at 1.0-10 L / min, the inclined plate spacing in the second-stage RC gravity separation operation is controlled at 1.0-5.0 mm, and the fluidized water speed of the feed is controlled at 0.1-0.4 L / min. The bottom flow obtained is the final iron concentrate.

2. The magnetic-gravity combined iron separation process of vanadium-titanium magnetite according to claim 1, characterized in that: In step A, the particle size of the vanadium-titanium magnetite is -12mm≥90%.

3. The magnetic-gravity combined iron separation process of vanadium-titanium magnetite according to claim 1, characterized in that: In step B, the magnetic field strength of the first magnetic separation is controlled at 1000-5000 Oe.

4. The magnetic-gravity combined iron separation process of vanadium-titanium magnetite according to claim 1, characterized in that: In step D, the magnetic field strength of the second magnetic separation is controlled at 1500-5000 Oe.

5. The magnetic-gravity combined iron separation process of vanadium-titanium magnetite according to any one of claims 1 to 4, characterized in that: In step G, the magnetic field strength of the third magnetic separation is controlled at 3000-5000 Oe.

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