A method of reducing overgrinding of ilmenite

Abstract

This invention discloses a method for reducing over-grinding of ilmenite, comprising: grinding the raw ore; performing weak magnetic pre-selection on the ground material to obtain tailings W1 and concentrate J1; performing a first classification on concentrate J1 to obtain underflow S1 and overflow Y1; performing a first weak magnetic separation on overflow Y1 to obtain tailings W2 and concentrate J2; performing a second classification on concentrate J2 to obtain underflow S2 and overflow Y2; performing fine screening on overflow Y2 to obtain oversize SS1 and undersize SX1; performing a second grinding on underflow S2 and oversize SS1; performing weak magnetic pre-selection on the second-grinded material to obtain tailings W3 and concentrate J3; adding concentrate J3 to the equipment used for the second classification; performing weak magnetic separation on undersize SX1 to obtain tailings W4 and concentrate J4; and performing a third classification and third magnetic separation on concentrate J4 to obtain tailings W5 and vanadium-ilmenite concentrate. This invention improves grinding and classification efficiency and reduces over-grinding of ilmenite.

Description

Technical Field

[0001] This invention relates to the field of vanadium-titanium magnetite beneficiation technology, and more specifically to a method for reducing over-grinding of ilmenite. Background Technology

[0002] Grinding is a process that uses the impact and abrasive action of grinding media and the ore itself to fully liberate valuable minerals and gangue, and is a prerequisite for mineral separation. Moreover, mineral beneficiation is often limited by the particle size of the material. Concentrates with excessively coarse particles have higher recovery rates but lower grades, while concentrates with excessively fine particles have higher grades but lower recovery rates. Practice shows that mineral beneficiation operations require a high degree of liberation of the target mineral in the grinding product, along with a low amount of coarse-grained material, a low amount of fine-grained material, and a high amount of easily beneficiated intermediate-grained material, i.e., a relatively uniform product particle size. In production practice, grinding aims to achieve the required liberation of minerals and meet the desired particle size, with mineral liberation being the primary objective. However, in actual production, some minerals that have already been liberated are often further ground, causing the mineral particle size to decrease and resulting in over-grinding.

[0003] Ilmenite crystals generally have a coarse grain size, with a liberation degree of 85% typically for particles smaller than 0.2 mm and 95% for particles smaller than 0.154 mm. Therefore, the grinding particle size can be relatively coarse, achieving the required liberation degree while avoiding over-grinding that leads to mud formation. However, currently, vanadium-titanium magnetite beneficiation plants continuously finely grind the ore to ensure iron concentrate grade, thereby increasing the liberation degree of ilmenite. This results in increasingly excessive over-grinding of ilmenite, a higher content of ultrafine ilmenite, and a greater proportion of particles smaller than 19 μm in the iron ore tailings, leading to increasingly prominent mud formation. Production practice shows that over-grinding produces a large amount of slime, increasing reagent consumption, reducing ilmenite recovery, and wasting titanium resources.

[0004] Therefore, there is an urgent need in this field to study a method to reduce the over-grinding of ilmenite. Summary of the Invention

[0005] The purpose of this invention is to provide a method for reducing the over-grinding of ilmenite to solve at least one of the above-mentioned problems existing in the prior art.

[0006] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0007] According to one aspect of the present invention, a method for reducing over-grinding of ilmenite is provided, the method comprising the following steps:

[0008] Step S1: Grind the crushed raw ore, and control the grinding fineness to 35-45% of the particles to be -0.074mm.

[0009] Step S2: Perform a first weak magnetic pre-selection on the discharged material after grinding to obtain tailings W1 and concentrate J1. The magnetic field strength of the first weak magnetic pre-selection is controlled between 0.2 and 0.4T.

[0010] Step S3: Perform the first classification operation on concentrate J1 to obtain underflow S1 and overflow Y1;

[0011] Step S4: Perform a first weak magnetic separation on the overflow Y1 to obtain tailings W2 and concentrate J2. The magnetic field strength of the first weak magnetic separation is controlled at 0.2~0.4T.

[0012] Step S5: Perform a second classification operation on concentrate J2 to obtain underflow S2 and overflow Y2;

[0013] Step S6: The overflow Y2 is subjected to iron selection and fine screening to obtain the oversize material SS1 and the undersize material SX1. The screen size of the fine screen is controlled between 0.154mm and 0.125mm.

[0014] Step S7: The underwash sand S2 and the oversize material SS1 are subjected to secondary grinding. The fineness of the secondary grinding is controlled to be 60-80% -0.074mm.

[0015] Step S8: Perform a second weak magnetic pre-selection on the discharged material after secondary grinding to obtain tailings W3 and concentrate J3, and add concentrate J3 to the equipment used in the second classification operation in step S5, wherein the magnetic field strength of the second weak magnetic pre-selection is controlled at 0.2~0.4T;

[0016] Step S9: Perform a second weak magnetic separation on the undersize material SX1 to obtain tailings W4 and concentrate J4. The magnetic field strength of the second weak magnetic separation is controlled between 0.15 and 0.35T.

[0017] Step S10: Perform a third classification and a third magnetic separation operation on concentrate J4 to obtain tailings W5 and vanadium-titanium iron concentrate.

[0018] According to one embodiment of the present invention, the method further includes performing titanium beneficiation operations on tailings W1, tailings W2, tailings W3 and tailings W4.

[0019] According to one embodiment of the present invention, the titanium selection operation includes the following steps:

[0020] Step ST1: After separating tailings W1, tailings W2, tailings W3 and tailings W4, concentrate and classify them to obtain sludge TS and overflow TY. Sludge TS is used as the first coarse-grained ilmenite CTK1, and overflow is used as the first fine-grained ilmenite XTK1.

[0021] Step ST2: The first coarse-grained ilmenite CTK1 is subjected to iron removal, strong magnetic roughing, strong magnetic scavenging, classification, and fine screening operations in sequence to obtain various coarse-grained titanium ore tailings and various coarse-grained titanium ore concentrates with different magnetic properties and particle sizes.

[0022] Step ST3: The first fine-grained ilmenite XTK1 is subjected to iron removal, strong magnetic roughing and strong magnetic scavenging operations in sequence to obtain various fine-grained titanium ore tailings and various fine-grained titanium ore concentrates with different magnetic properties and particle sizes.

[0023] Step ST4: Combine the coarse-grained titanium ore concentrate and the fine-grained titanium ore concentrate, then concentrate and flotate them to obtain titanium concentrate.

[0024] According to one embodiment of the present invention, the process of coarsely separating tailings W1, tailings W2, tailings W3, and tailings W4 and then concentrating and classifying them includes:

[0025] Tailings W1 and tailings W2 were combined, separated, and then subjected to the first concentration and classification to obtain sediment TS1 and overflow TY1.

[0026] Tailings W3 and tailings W4 were combined and separated into coarse layers for a second concentration and classification process to obtain sediment TS2 and overflow TY2.

[0027] The sediment TS1 and sediment TS2 were combined into the first coarse-grained ilmenite CTK1, and the overflow TY1 and overflow TY2 were combined into the first fine-grained ilmenite XTK1.

[0028] According to an embodiment of the present invention, step ST2, which sequentially performs iron removal, strong magnetic coarsening, strong magnetic scavenging, classification, and fine screening operations on the first coarse-grained ilmenite CTK1, includes:

[0029] Step ST2-1: Perform the first iron removal operation on the first coarse-grained ilmenite CTK1 to obtain concentrate CTJ1 and tailings CTW1. The magnetic field strength for iron removal is 0.1~0.3T.

[0030] Step ST2-2: The tailings CTW1 are subjected to a first strong magnetic coarsening to obtain concentrate CTJ2 and tailings CTW2. The magnetic field strength of the first strong magnetic coarsening is 0.7~1.3T.

[0031] Step ST2-3: Perform a first strong magnetic sweep on tailings CTW2 to obtain concentrate CTJ3 and tailings CTW3. The magnetic field strength of the first strong magnetic sweep is 0.7~1.3T.

[0032] Step ST2-4: After merging concentrate CTJ2 and concentrate CTJ3, classify them to obtain coarse-grained overflow CTY1 and underflow CTS1;

[0033] Step ST2-5: Perform fine screening on the coarse-grained overflow CTY1 to obtain the coarse-grained oversize material CSS1 and the coarse-grained undersize material CSX1. The screen size of the fine screen is controlled between 0.154 mm and 0.1 mm.

[0034] Step ST2-6: Combine the underwash CTS1 and the coarse-grained screen material CSS1, grind them together, and add them to the equipment used in the classification operation of step ST2-4. The grinding fineness is controlled at -0.074mm, accounting for 40-60%.

[0035] According to an embodiment of the present invention, step ST2, which sequentially performs iron removal, strong magnetic roughing, strong magnetic scavenging, classification, and fine screening operations on the first coarse-grained ilmenite CTK1, further includes:

[0036] Step ST2-7: Perform a second iron removal operation on the coarse-grained undersize material CSX1 to obtain concentrate CTJ4 and tailings CTW4;

[0037] Step ST2-8: The tailings CTW4 are subjected to a second strong magnetic coarsening to obtain concentrate CTJ5 and tailings CTW5. The magnetic field strength of the second strong magnetic coarsening is 0.8~1.3T.

[0038] Step ST2-9: Perform a second strong magnetic sweep on tailings CTW5 to obtain concentrate CTJ6 and tailings CTW6. The magnetic field strength of the second strong magnetic sweep is 0.8 to 1.3 T.

[0039] According to an embodiment of the present invention, step ST3, which sequentially performs iron removal, strong magnetic coarsening, and strong magnetic scavenging operations on the first fine-grained ilmenite XTK1, includes:

[0040] Step ST3-1: Perform iron removal operation on the first fine-grained ilmenite XTK1 to obtain concentrate XTJ1 and tailings XTW1;

[0041] Step ST3-2: Perform strong magnetic coarse separation on tailings XTW1 to obtain concentrate XTJ2 and tailings XTW2;

[0042] Step ST3-3: Perform strong magnetic scavenging on tailings XTW2 to obtain concentrate XTJ3 and tailings XTW3.

[0043] According to one embodiment of the present invention, step ST4, which combines coarse-grained and fine-grained titanium ore concentrates and then concentrates and flotates them, includes:

[0044] Step ST4-1: Combine concentrate XTJ2, concentrate XTJ3, concentrate CTJ5 and concentrate CTJ6 for the third concentration operation to obtain sludge TS3 and overflow TY3;

[0045] Step ST4-2: Perform sulfur and titanium flotation operations on the sludge TS3 to obtain titanium concentrate.

[0046] According to an embodiment of the present invention, step S10, which involves a third grading and a third magnetic separation of concentrate J4, includes:

[0047] Step S10-1: Perform a third classification on concentrate J4 to obtain underflow sand S3 and overflow Y3;

[0048] Step S10-2: Perform a second iron-selecting fine sieve classification on the overflow Y3 to obtain the oversize material SS2 and the undersize material SX2, wherein the sieve size of the fine sieve is controlled between 0.125mm and 0.1mm;

[0049] Step S10-3: Grind the underfill sand S3 and the overfill material SS2 in a tower mill, and perform weak magnetic separation on the underfill material SX2 to obtain tailings W5 and vanadium-titanium iron concentrate. The grinding fineness is controlled at -0.074mm, accounting for 90-100%, and the magnetic field strength of the weak magnetic separation is controlled at 0.15-0.3T.

[0050] According to one embodiment of the present invention, the method further includes:

[0051] Step S11: Combine overflow TY3 and tailings W5 for the fourth concentration operation to obtain sediment S4 and overflow Y4;

[0052] Step S12: Deslim the sediment S4 to obtain deslimed sediment S5 and overflow Y5;

[0053] Step S13: Perform sulfur and titanium flotation operations on the deslimed sand S5 to obtain ultrafine titanium concentrate.

[0054] By adopting the above technical solutions, the method provided by the present invention has at least one of the following beneficial effects compared with the prior art:

[0055] (1) By setting weak magnetic pre-selection (i.e., first weak magnetic pre-selection and second weak magnetic pre-selection) before the classification operation, some of the softer tailings (i.e. tailings W1 and tailings W3) are separated in advance and enter the titanium beneficiation process in advance, avoiding the tailings from entering the iron beneficiation mill for grinding. The grinding amount is reduced by about 40% after the first weak magnetic pre-selection and by about 13% after the second weak magnetic pre-selection, which reduces the over-grinding of ilmenite, reduces the degree of mudding, and can improve the grade of iron concentrate.

[0056] (2) Performing weak magnetic pre-selection after the first grinding and discharge can greatly reduce the amount of ore entering the classification equipment, improve classification efficiency, and reduce the load of secondary grinding.

[0057] (3) Performing a second weak magnetic pre-selection after the second grinding and ore discharge can reduce the amount of ore entering the second classification operation equipment, improve the efficiency of the second classification operation, and reduce the load of subsequent circulating grinding.

[0058] (4) The titanium beneficiation process adopts separate grinding and separation and narrow-particle strong magnetic enrichment and mixed flotation to recover titanium concentrate. The narrow-particle separation method is conducive to reducing the amount of tailings concentration, reducing beneficiation energy consumption, improving the beneficiation efficiency of ilmenite, and further improving the recovery rate of ilmenite.

[0059] (5) The concentrate overflows from coarse-grained strong magnetic and fine-grained strong magnetic separation are combined with the tailings from the third weak magnetic separation and then separately concentrated, deslimed and floated to obtain ultrafine titanium concentrate, which improves the recovery rate of ilmenite. Attached Figure Description

[0060] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0061] Figure 1 This is a flowchart of a method for reducing over-grinding of ilmenite according to an embodiment of the present invention. Detailed Implementation

[0062] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0063] Furthermore, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0064] The minerals in vanadium-titanium magnetite mainly include titanite and ilmenite, which have significantly different hardness. Ilmenite has less magnetic properties than titanite, and the two can be separated by a magnetic field. Therefore, the magnetic separation operations of this invention, such as weak magnetic pre-selection, weak magnetic separation, strong magnetic roughing, and strong magnetic scavenging, all separate materials based on this principle.

[0065] In this invention, the term "concentrate" refers to minerals with high magnetic properties obtained by magnetic separation equipment, and the term "tailings" refers to another portion of minerals with relatively weak magnetic properties obtained by magnetic separation equipment.

[0066] This invention provides a method for reducing over-grinding of ilmenite. For example... Figure 1 As shown, the method generally includes the following steps:

[0067] Step S1: Grind the crushed raw ore;

[0068] Step S2: Perform a first weak magnetic pre-selection on the discharged material after grinding to obtain tailings W1 and concentrate J1;

[0069] Step S3: Perform the first classification operation on concentrate J1 to obtain underflow S1 and overflow Y1;

[0070] Step S4: Perform a first weak magnetic separation on the overflow Y1 to obtain tailings W2 and concentrate J2;

[0071] Step S5: Perform a second classification operation on concentrate J2 to obtain underflow S2 and overflow Y2;

[0072] Step S6: Perform iron selection and fine screening on the overflow Y2 to obtain the oversize material SS1 and the undersize material SX1;

[0073] Step S7: Grind the underfill sand S2 and the overfill material SS1 for a second time;

[0074] Step S8: Perform a second weak magnetic pre-selection on the discharged material after secondary grinding to obtain tailings W3 and concentrate J3, and add concentrate J3 to the equipment used in the second classification operation in step S5;

[0075] Step S9: Perform a second weak magnetic separation on the undersize material SX1 to obtain tailings W4 and concentrate J4;

[0076] Step S10: Perform a third classification and a third magnetic separation operation on concentrate J4 to obtain tailings W5 and vanadium-titanium iron concentrate.

[0077] The following is a detailed description of each step.

[0078] In step S1, the crushed raw ore is ground. Grinding can be performed using a ball mill to break the crushed raw ore into smaller particles. Specifically, the grinding fineness is controlled to be -0.074 mm, accounting for 35-45%.

[0079] In step S2, the discharged ore after grinding undergoes a first weak magnetic pre-selection to obtain tailings W1 and concentrate J1. The magnetic field strength of the first weak magnetic pre-selection is controlled between 0.2 and 0.4 T. As described above, the first weak magnetic pre-selection essentially separates ilmenite and titanomagnetite, which have different magnetic intensities. Performing the first weak magnetic pre-selection before subsequent classification operations can separate some of the softer tailings in advance, allowing them to enter the titanium beneficiation process earlier and avoiding their entry into the iron beneficiation mill. The grinding volume is reduced by approximately 40% after the first weak magnetic pre-selection.

[0080] In step S3, the concentrate J1 undergoes a first classification operation to obtain underflow S1 and overflow Y1. Specifically, the concentrate J1 can be added to a first hydrocyclone for separation. The first hydrocyclone is used to classify the crushed minerals by particle size, sending minerals of suitable size (i.e., those included in overflow Y1) to the next step for magnetic separation, while the other portions with unsuitable (larger) particle sizes are screened out and can be either returned to the grinding operation for further grinding or discharged as tailings.

[0081] In step S4, the overflow Y1 undergoes a first weak magnetic separation to obtain tailings W2 and concentrate J2. The magnetic field strength of the first weak magnetic separation is controlled between 0.2 and 0.4 T. As described above, the first weak magnetic separation separates ilmenite and titanomagnetite, which have different magnetic strengths. Performing the first weak magnetic separation before subsequent classification operations can separate some of the softer tailings in advance, allowing them to enter the titanium beneficiation process earlier and preventing these tailings from entering the iron beneficiation mill for grinding.

[0082] In step S5, the concentrate J2 undergoes a second classification operation to obtain underflow S2 and overflow Y2. Specifically, the concentrate J2 can be added to a second hydrocyclone for separation. The second hydrocyclone is used to classify the minerals in the concentrate J2 by ​​particle size, sending minerals of suitable particle size (i.e., those included in the overflow Y2) to the next step for fine screening, while other portions with unsuitable (larger) particle sizes (such as underflow S2) are screened out and can be optionally returned to the grinding operation for further grinding.

[0083] In step S6, the overflow Y2 is subjected to iron-selective fine screening to obtain oversize material SS1 and undersize material SX1. The screen size of the iron-selective fine screen is controlled between 0.154 mm and 0.125 mm. This operation can further separate materials of different particle sizes. For example, the larger oversize material SS1 can be screened out and returned to the grinding operation for further grinding, while the smaller undersize material SX1 can be subjected to the next step of magnetic separation.

[0084] In step S7, the underflow sand S2 obtained in step S5 and the overflow material SS1 obtained in step S6 are subjected to secondary grinding. Secondary grinding can be performed using a ball mill to grind these larger-sized minerals into smaller-sized minerals. Specifically, the fineness of the ball mill grinding is controlled to be -0.074 mm, accounting for 60-80%.

[0085] In step S8, the discharged material after secondary grinding undergoes a second weak magnetic pre-selection to obtain tailings W3 and concentrate J3. Concentrate J3 is then added to the equipment used in the second classification operation of step S5. The magnetic field strength of the second weak magnetic pre-selection is controlled between 0.2 and 0.4 T. As described above, the second weak magnetic pre-selection essentially separates ilmenite and titanomagnetite, which have different magnetic intensities. Performing the second weak magnetic pre-selection before subsequent classification operations can pre-separate some of the softer tailings, allowing them to enter the titanium beneficiation process earlier and preventing these tailings from entering the iron beneficiation mill. The grinding volume is reduced by approximately 13% after the second weak magnetic pre-selection.

[0086] In step S9, the undersize material SX1 is subjected to a second weak magnetic separation to obtain tailings W4 and concentrate J4. The magnetic field strength of the second weak magnetic separation is controlled between 0.15 and 0.35 T. As described above, the second weak magnetic separation essentially separates ilmenite and titanomagnetite, which have different magnetic strengths, from each other.

[0087] In step S10, the concentrate J4 undergoes a third classification and a third magnetic separation to obtain tailings W5 and vanadium-titanium iron concentrate. In some embodiments, the third classification and third magnetic separation of concentrate J4 includes:

[0088] Step S10-1: Perform a third classification on concentrate J4 to obtain underflow sand S3 and overflow Y3;

[0089] Step S10-2: Perform a second iron-selecting fine sieve classification on the overflow Y3 to obtain the oversize material SS2 and the undersize material SX2, wherein the sieve size of the fine sieve is controlled between 0.125mm and 0.1mm;

[0090] Step S10-3: Grind the underfill sand S3 and the overfill material SS2 in a tower mill, and perform weak magnetic separation on the underfill material SX2 to obtain tailings W5 and vanadium-titanium iron concentrate. The grinding fineness is controlled at -0.074mm, accounting for 90-100%, and the magnetic field strength of the weak magnetic separation is controlled at 0.15-0.3T.

[0091] Optionally, in some embodiments, the method further includes titanium beneficiation operations on tailings W1, tailings W2, tailings W3, and tailings W4. The titanium beneficiation operation generally includes the following steps:

[0092] Step ST1: After separating tailings W1, tailings W2, tailings W3 and tailings W4, concentrate and classify them to obtain sludge TS and overflow TY. Sludge TS is used as the first coarse-grained ilmenite CTK1, and overflow is used as the first fine-grained ilmenite XTK1.

[0093] Step ST2: The first coarse-grained ilmenite CTK1 is subjected to iron removal, strong magnetic roughing, strong magnetic scavenging, classification, and fine screening operations in sequence to obtain various coarse-grained titanium ore tailings and various coarse-grained titanium ore concentrates with different magnetic properties and particle sizes.

[0094] Step ST3: The first fine-grained ilmenite XTK1 is subjected to iron removal, strong magnetic roughing and strong magnetic scavenging operations in sequence to obtain various fine-grained titanium ore tailings and various fine-grained titanium ore concentrates with different magnetic properties and particle sizes.

[0095] Step ST4: Combine the coarse-grained titanium ore concentrate and the fine-grained titanium ore concentrate, then concentrate and flotate them to obtain titanium concentrate.

[0096] In some embodiments, the step ST1 of separating tailings W1, tailings W2, tailings W3, and tailings W4 and then performing concentration and classification may further include:

[0097] Tailings W1 and tailings W2 were combined, separated, and then subjected to the first concentration and classification to obtain sediment TS1 and overflow TY1.

[0098] Tailings W3 and tailings W4 were combined and separated into coarse layers for a second concentration and classification process to obtain sediment TS2 and overflow TY2.

[0099] The sediment TS1 and sediment TS2 were combined into the first coarse-grained ilmenite CTK1, and the overflow TY1 and overflow TY2 were combined into the first fine-grained ilmenite XTK1.

[0100] Optionally, in some embodiments, step ST2, which sequentially performs iron removal, strong magnetic coarsening, strong magnetic scavenging, classification, and fine screening on the first coarse-grained ilmenite CTK1, may include:

[0101] Step ST2-1: Perform the first iron removal operation on the first coarse-grained ilmenite CTK1 to obtain concentrate CTJ1 and tailings CTW1. The optimal magnetic field strength for iron removal is 0.1 to 0.3 T.

[0102] Step ST2-2: Perform a first strong magnetic coarsening on tailings CTW1 to obtain concentrate CTJ2 and tailings CTW2. The optimal magnetic field strength for strong magnetic coarsening is 0.7 to 1.3 T.

[0103] Step ST2-3: Perform a first strong magnetic scavenging on tailings CTW2 to obtain concentrate CTJ3 and tailings CTW3. The optimal magnetic field strength for strong magnetic scavenging is 0.7 to 1.3 T.

[0104] Step ST2-4: After merging concentrate CTJ2 and concentrate CTJ3, classify them to obtain coarse-grained overflow CTY1 and underflow CTS1;

[0105] Step ST2-5: Perform fine screening on the coarse-grained overflow CTY1 to obtain the coarse-grained oversize material CSS1 and the coarse-grained undersize material CSX1, wherein the screen size of the fine screen is controlled between 0.154 mm and 0.1 mm.

[0106] Step ST2-6: Combine the underwash CTS1 and the coarse-grained screen material CSS1, grind them together, and add them to the equipment used in the classification operation of step ST2-4. The ball milling fineness is controlled at -0.074mm, accounting for 40-60%.

[0107] Optionally, in some embodiments, step ST2, which sequentially performs iron removal, strong magnetic coarsening, strong magnetic scavenging, classification, and fine screening on the first coarse-grained ilmenite CTK1, may further include:

[0108] Step ST2-7: Perform a second iron removal operation on the coarse-grained undersize material CSX1 to obtain concentrate CTJ4 and tailings CTW4;

[0109] Step ST2-8: The tailings CTW4 are subjected to a second strong magnetic coarsening to obtain concentrate CTJ5 and tailings CTW5. The optimal magnetic field strength for the second strong magnetic coarsening is 0.8 to 1.3 T.

[0110] Step ST2-9: Perform a second strong magnetic scavenging on tailings CTW5 to obtain concentrate CTJ6 and tailings CTW6. The optimal magnetic field strength for the second strong magnetic scavenging is 0.8 to 1.3 T.

[0111] Optionally, in some embodiments, step ST3, which sequentially performs iron removal, strong magnetic coarsening, and strong magnetic scavenging on the first fine-grained ilmenite XTK1, may include:

[0112] Step ST3-1: Perform iron removal operation on the first fine-grained ilmenite XTK1 to obtain concentrate XTJ1 and tailings XTW1;

[0113] Step ST3-2: Perform strong magnetic coarse separation on tailings XTW1 to obtain concentrate XTJ2 and tailings XTW2;

[0114] Step ST3-3: Perform strong magnetic scavenging on tailings XTW2 to obtain concentrate XTJ3 and tailings XTW3.

[0115] Optionally, in some embodiments, step ST4, which combines coarse-grained and fine-grained titanium ore concentrates for concentration and flotation, includes:

[0116] Step ST4-1: Combine concentrate XTJ2, concentrate XTJ3, concentrate CTJ5 and concentrate CTJ6 for the third concentration operation to obtain sludge TS3 and overflow TY3;

[0117] Step ST4-2: Perform sulfur and titanium flotation operations on the TS3 sediment to obtain titanium concentrate;

[0118] Sulfur flotation should be carried out with one roughing and one to three scavenging processes, while titanium flotation should be carried out with one roughing and two to four cleaning processes.

[0119] Optionally, in some embodiments, the method may further include:

[0120] Step S11: Combine overflow TY3 and tailings W5 for the fourth concentration operation to obtain sediment S4 and overflow Y4;

[0121] Step S12: Deslim the sediment S4 to obtain deslimed sediment S5 and overflow Y5;

[0122] Step S13: Perform sulfur and titanium flotation operations on the deslimed sand S5 to obtain ultrafine titanium concentrate;

[0123] For sulfur flotation, one roughing and one to three scavenging processes are recommended. For titanium flotation, one roughing and two to four cleaning processes are recommended. For ultrafine particle flotation, flotation machines or flotation columns can be used.

[0124] The method of this invention can be used to recover and utilize vanadium-titanium magnetite, and can obtain vanadium-titanium iron concentrate with a TFe grade of 55% and a TFe recovery rate of 65% and titanium concentrate with a TiO2 grade of 47% and a relative TiO2 recovery rate of about 55%.

[0125] The table below shows the results of a first-stage ball mill pre-selection (i.e., after the first weak magnetic pre-selection of the ore after one ball mill) and a second-stage ball mill pre-selection (i.e., after the second weak magnetic pre-selection of the ore after two ball mills) at a vanadium-titanium magnetite beneficiation plant in Panzhihua using the method of the present invention.

[0126] Table 1. Pre-selection results of the first and second stages of ball-bearing processes at a vanadium-titanium magnetite beneficiation plant in Panzhihua.

[0127]

[0128] Based on the above practical results, it can be seen that by using the method of the present invention, the grinding amount is reduced by about 40% after the first weak magnetic pre-selection and by about 13% after the second weak magnetic pre-selection. This method reduces the over-grinding of ilmenite, reduces the degree of mudding, and can improve the grade of iron concentrate.

[0129] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0130] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0131] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for reducing over-grinding of ilmenite, characterized in that, Includes the following steps: Step S1: Grind the crushed raw ore, controlling the grinding fineness to be -0.074mm, accounting for 35-45%; Step S2: Perform a first weak magnetic pre-selection on the discharged material after grinding to obtain tailings W1 and concentrate J1. The magnetic field strength of the first weak magnetic pre-selection is controlled between 0.2 and 0.4T. Step S3: Perform the first classification operation on concentrate J1 to obtain underflow S1 and overflow Y1; Step S4: Perform a first weak magnetic separation on the overflow Y1 to obtain tailings W2 and concentrate J2. The magnetic field strength of the first weak magnetic separation is controlled at 0.2~0.4T. Step S5: Perform a second classification operation on concentrate J2 to obtain underflow S2 and overflow Y2; Step S6: The overflow Y2 is subjected to iron selection and fine screening to obtain the oversize material SS1 and the undersize material SX1. The screen size of the fine screen is controlled between 0.154mm and 0.125mm. Step S7: The underwash sand S2 and the oversize material SS1 are subjected to secondary grinding. The fineness of the secondary grinding is controlled to be 60-80% -0.074mm. Step S8: Perform a second weak magnetic pre-selection on the discharged material after secondary grinding to obtain tailings W3 and concentrate J3, and add concentrate J3 to the equipment used in the second classification operation in step S5, wherein the magnetic field strength of the second weak magnetic pre-selection is controlled at 0.2~0.4T; Step S9: Perform a second weak magnetic separation on the undersize material SX1 to obtain tailings W4 and concentrate J4. The magnetic field strength of the second weak magnetic separation is controlled between 0.15 and 0.35T. Step S10: Perform third classification and third magnetic separation operations on concentrate J4 to obtain tailings W5 and vanadium-titanium iron concentrate; The method further includes titanium beneficiation operations on tailings W1, tailings W2, tailings W3, and tailings W4, the titanium beneficiation operations comprising the following steps: Step ST1: After separating tailings W1, tailings W2, tailings W3 and tailings W4 into coarse particles, they are concentrated and classified to obtain sludge TS and overflow TY. Sludge TS is used as the first coarse-grained ilmenite CTK1, and overflow is used as the first fine-grained ilmenite XTK1. Step ST2: The first coarse-grained ilmenite CTK1 is subjected to iron removal, strong magnetic roughing, strong magnetic scavenging, classification, and fine screening operations in sequence to obtain various coarse-grained titanium ore tailings and various coarse-grained titanium ore concentrates with different magnetic properties and particle sizes. Step ST3: The first fine-grained ilmenite XTK1 is subjected to iron removal, strong magnetic roughing and strong magnetic scavenging operations in sequence to obtain various fine-grained titanium ore tailings and various fine-grained titanium ore concentrates with different magnetic properties and particle sizes. Step ST4: Combine the coarse-grained titanium ore concentrate and the fine-grained titanium ore concentrate, then concentrate and flotate them to obtain titanium concentrate.

2. The method according to claim 1, characterized in that, After coarse separation, tailings W1, tailings W2, tailings W3, and tailings W4 are concentrated and classified, including: Tailings W1 and tailings W2 were combined, separated, and then subjected to the first concentration and classification to obtain sediment TS1 and overflow TY1. Tailings W3 and tailings W4 were combined and separated into coarse layers for a second concentration and classification process to obtain sediment TS2 and overflow TY2. The sediment TS1 and sediment TS2 were combined into the first coarse-grained ilmenite CTK1, and the overflow TY1 and overflow TY2 were combined into the first fine-grained ilmenite XTK1.

3. The method according to claim 1, characterized in that, Step ST2 involves sequentially performing iron removal, strong magnetic roughing, strong magnetic scavenging, classification, and fine screening operations on the first coarse-grained ilmenite CTK1, including: Step ST2-1: Perform the first iron removal operation on the first coarse-grained ilmenite CTK1 to obtain concentrate CTJ1 and tailings CTW1. The magnetic field strength for iron removal is 0.1~0.3T. Step ST2-2: The tailings CTW1 are subjected to a first strong magnetic coarsening to obtain concentrate CTJ2 and tailings CTW2. The magnetic field strength of the first strong magnetic coarsening is 0.7~1.3T. Step ST2-3: Perform a first strong magnetic sweep on tailings CTW2 to obtain concentrate CTJ3 and tailings CTW3. The magnetic field strength of the first strong magnetic sweep is 0.7~1.3T. Step ST2-4: After merging concentrate CTJ2 and concentrate CTJ3, classify them to obtain coarse-grained overflow CTY1 and underflow CTS1; Step ST2-5: Perform fine screening on the coarse-grained overflow CTY1 to obtain the coarse-grained oversize material CSS1 and the coarse-grained undersize material CSX1. The screen size of the fine screen is controlled between 0.154 mm and 0.1 mm. Step ST2-6: Combine the underwash CTS1 and the coarse-grained screen material CSS1, grind them together, and add them to the equipment used in the classification operation of step ST2-4. The grinding fineness is controlled at -0.074mm, accounting for 40-60%.

4. The method according to claim 3, characterized in that, Step ST2, which sequentially performs iron removal, strong magnetic roughing, strong magnetic scavenging, classification, and fine screening on the first coarse-grained ilmenite CTK1, also includes: Step ST2-7: Perform a second iron removal operation on the coarse-grained undersize material CSX1 to obtain concentrate CTJ4 and tailings CTW4; Step ST2-8: The tailings CTW4 are subjected to a second strong magnetic coarsening to obtain concentrate CTJ5 and tailings CTW5. The magnetic field strength of the second strong magnetic coarsening is 0.8~1.3T. Step ST2-9: Perform a second strong magnetic sweep on tailings CTW5 to obtain concentrate CTJ6 and tailings CTW6. The magnetic field strength of the second strong magnetic sweep is 0.8 to 1.3 T.

5. The method according to claim 4, characterized in that, Step ST3 involves sequentially performing iron removal, strong magnetic roughing, and strong magnetic scavenging operations on the first fine-grained ilmenite XTK1, including: Step ST3-1: Perform iron removal operation on the first fine-grained ilmenite XTK1 to obtain concentrate XTJ1 and tailings XTW1; Step ST3-2: Perform strong magnetic coarse separation on tailings XTW1 to obtain concentrate XTJ2 and tailings XTW2; Step ST3-3: Perform strong magnetic scavenging on tailings XTW2 to obtain concentrate XTJ3 and tailings XTW3.

6. The method according to claim 5, characterized in that, Step ST4, which combines coarse-grained and fine-grained titanium ore concentrates for concentration and flotation, includes: Step ST4-1: Combine concentrate XTJ2, concentrate XTJ3, concentrate CTJ5 and concentrate CTJ6 for the third concentration operation to obtain sludge TS3 and overflow TY3; Step ST4-2: Perform sulfur and titanium flotation operations on the sludge TS3 to obtain titanium concentrate.

7. The method according to claim 6, characterized in that, Step S10, which involves the third grading and third magnetic separation of concentrate J4, includes: Step S10-1: Perform a third classification on concentrate J4 to obtain underflow sand S3 and overflow Y3; Step S10-2: Perform a second iron-selecting fine sieve classification on the overflow Y3 to obtain the oversize material SS2 and the undersize material SX2, wherein the sieve size of the fine sieve is controlled between 0.125mm and 0.1mm; Step S10-3: Grind the underfill sand S3 and the overfill material SS2 in a tower mill, and perform weak magnetic separation on the underfill material SX2 to obtain tailings W5 and vanadium-titanium iron concentrate. The grinding fineness is controlled at -0.074mm, accounting for 90-100%, and the magnetic field strength of the weak magnetic separation is controlled at 0.15-0.3T.

8. The method according to claim 7, characterized in that, The method further includes: Step S11: Combine overflow TY3 and tailings W5 for the fourth concentration operation to obtain sediment S4 and overflow Y4; Step S12: Deslim the sediment S4 to obtain deslimed sediment S5 and overflow Y5; Step S13: Perform sulfur and titanium flotation operations on the deslimed sand S5 to obtain ultrafine titanium concentrate.

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