Low-cost hematite alteration ilmenite beneficiation process

Abstract

The invention belongs to the technical field of beneficiation, and particularly relates to a low-cost hematite alteration ilmenite beneficiation process, which comprises the following steps: firstly, adding water into raw ore sand to make pulp until the pulp concentration reaches 20-45%, vibrating to separate coarse ore by using a slag separation sieve, and feeding the screened ore sand into a wet weak magnetic separator to obtain iron-removed ore sand; carrying out zirconium-titanium separation on the iron-removed ore sand through a wet-type strong magnetic separator, separating out titanium middlings and zirconium middlings, pumping the zirconium middlings to a table concentrator for gravity separation, filtering and drying the titanium middlings, feeding the titanium middlings into a dry-type high-speed magnetic separator, separating out titanium concentrate, iron-rich titanium middlings and zirconium middlings, reducing and roasting the selected iron-rich titanium middlings, and cooling, the method has the beneficial effects that zirconium and titanium are separated in advance through the wet high-speed magnetic separator, the non-magnetic zirconium middling is discharged, and the drying amount is reduced; most qualified titanium concentrate is directly separated by the dry high-speed magnetic separator, so that the amount of ore needing to be roasted is greatly reduced, and the production cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, specifically to a low-cost process for beneficiating ilmenite through hematite mineralization and alteration. Background Technology

[0002] In nature, most coastal placer deposits exhibit varying degrees of hematitic mineralization and alteration in their ilmenite. Hematite and ilmenite form complex intergrowth structures, making it difficult to liberate individual minerals even through grinding. Furthermore, the specific magnetic susceptibility of hematite and ilmenite is similar, resulting in low-grade titanium concentrates produced by current magnetic separators. The content can only reach about 42%, while (Content exceeding 22%), making it difficult to meet the demands of the downstream titanium dioxide industry. The requirement is a content of ≥46%. Although a combined magnetic roasting and magnetic separation process can produce qualified titanium concentrate, the roasting energy consumption is relatively high, resulting in high production costs and making the product difficult to compete in the market. In summary, the traditional beneficiation process for hematite-derived ilmenite has two major problems: either the concentrate grade is not up to standard or the production cost is too high. Summary of the Invention

[0003] The present invention addresses the problems mentioned above by designing a low-cost beneficiation process for hematite mineralization and alteration of ilmenite, thereby reducing beneficiation costs.

[0004] To achieve the above objectives, the present invention provides a low-cost beneficiation process for ilmenite mineralized by hematite alteration, comprising the following steps: Step 1: After adding water to the raw ore sand to make slurry until the slurry concentration reaches 20%~45%, use a slag screen to vibrate and coarse the ore sand. The screened ore sand is then fed into a wet weak magnetic separator to obtain iron-removed ore sand. Step 2: The iron ore sand is subjected to zirconium-titanium separation by a wet high-intensity magnetic separator to separate titanium middlings and zirconium middlings; Step 3: Filter and dry the titanium ore to obtain dried titanium ore; Step 4: The titanium middlings are fed into a dry high-speed magnetic separator to separate titanium concentrate, iron-rich titanium middlings, and zirconium middlings. Step 5: The iron-titanium middlings are reduced and roasted, and then separated again by the dry high-speed magnetic separator to obtain iron concentrate, titanium concentrate and zirconium middlings.

[0005] Furthermore, in step four, the dry high-speed magnetic separator is a permanent magnet drum magnetic separator with a drum rotation speed of 2.0 m / s to 6.0 m / s.

[0006] Further, the permanent magnet cylinder type magnetic separator is a double-layer structure, the upper layer is a weak magnetic cylinder, the magnetic field strength is 80kA / m~240kA / m, the rotating speed is 0.8m / s~1.5m / s, the strong magnetic iron in the titanium middlings is removed, the lower layer is a strong magnetic cylinder, the magnetic field strength is 480kA / m~800kA / m, the rotating speed is 2m / s~4m / s, two ore separating plates are arranged in the lower layer magnetic cylinder, three products can be separated at the same time, which are titanium concentrate, iron-titanium middlings and zirconium middlings.

[0007] Further, the magnetic field strength of the wet weak magnetic magnetic separator in the step one is 80kA / m~240kA / m, and the rotating speed is 0.5m / s~1m / s.

[0008] Further, the magnetic field strength of the wet strong magnetic magnetic separator in the step two is 800kA / m~1200kA / m.

[0009] Further, the titanium middlings filtering method in the step three adopts a belt filter, after filtering dry water, the titanium middlings are transferred to a drying furnace through a belt conveyor, the water is dried to below 0.5%, and the dried titanium middlings are obtained.

[0010] In summary, the present application has the following advantages and beneficial technical effects: 1. In the present application, the iron concentrate is discharged through the wet weak magnetic magnetic separator in the step one, and the non-magnetic zirconium middlings are discharged through the wet strong magnetic magnetic separator in the step two, so that the amount of ore needing drying treatment is significantly reduced, and the energy consumption cost is saved.

[0011] 2. In the present application, the dry high-speed magnetic separator with a double-layer structure is used in the step four, the upper layer is used to remove the strong magnetic iron in the titanium middlings, and the lower layer is used to select a large amount of qualified titanium concentrate, so that the amount of ore needing roasting treatment is greatly reduced, and the production cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0012] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description, taken in conjunction with the following drawings, in which: Figure 1 is a process flow chart of the present application. DETAILED DESCRIPTION

[0013] For the purpose, technical scheme and advantages of the present application, the technical scheme in the embodiments of the present application will be described in more detail below in conjunction with the drawings in the embodiments of the present application. In the drawings, the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout; the described embodiments are part of the embodiments of the present application, not all; the embodiments described below and the directional terms are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application; based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application. The embodiments of the present application will be described in detail below in conjunction with the drawings: The following will be described in conjunction with the drawings Figure 1 The present application will be further described in detail: As Figure 1 shown, the present embodiment discloses a low-cost ilmenite beneficiation process of hematite alteration, comprising the following steps: Step one: the raw ore sand is slurried with water to a pulp concentration of about 35%, the coarse residue is screened out by a coarse residue vibration screen, and the remaining ore sand is fed into a wet low-intensity magnetic separator, the magnetic field strength of the wet low-intensity magnetic separator is 160 kA / m, and the rotating speed is 0.628 m / s, so as to select iron concentrate and de-iron ore sand.

[0014] Step two: the de-iron ore sand is fed into a wet high-intensity magnetic separator, the magnetic field strength is 800 kA / m, and the titanium middlings and zircon middlings are selected.

[0015] Step three: the titanium middlings are fed into a belt filter, dried, and then transferred to a drying furnace by a belt conveyor, the moisture is dried to below 0.5%, and the dried titanium middlings are obtained.

[0016] Step four: the dried titanium middlings are fed into a dry magnetic separator for separation, the magnetic system of the dry magnetic separator includes fan-shaped cross-section main magnetic poles and auxiliary magnetic poles, the auxiliary magnetic poles on both sides of the main magnetic poles have the same polarity as the main magnetic poles, and the adjacent main magnetic poles have opposite polarities, the main magnetic poles and the auxiliary magnetic poles are fixed on the magnetic yoke body by screws, the magnetic system included angle is 90°~360°, and the main magnetic poles are alternately arranged along the circumferential direction.

[0017] In the present embodiment, the dry magnetic separator is preferably a double-layer structure permanent magnetic cylinder type magnetic separator, which adopts a permanent magnetic roller, the upper layer is a low-intensity magnetic cylinder, the magnetic field strength is 160 kA / m, and the rotating speed is 1.0 m / s, which is used to further remove the strong magnetic iron in the titanium middlings, i.e. iron-titanium middlings, the lower layer is a high-intensity magnetic cylinder, the magnetic field strength is 560 kA / m, and the rotating speed is 2.35 m / s, two ore separation plates are arranged in the lower layer magnetic cylinder, and step five can separate three products, which are titanium concentrate, iron-titanium rich middlings and zircon middlings.

[0018] Step five: after the iron-rich titanium middlings are fully reduced in a rotary kiln in a reducing atmosphere, they are separated by the dry high-speed magnetic separator in step four to obtain iron concentrate, titanium concentrate and zirconium middlings.

[0019] Example one A certain beach placer of hematite-weathered ilmenite, the raw material in the sample 、 , hematite (brown ore), trivalent iron The contents are 31.80wt%, 33.59wt%, 22.8wt%, and 28.66wt% respectively. The low-cost recovery of ilmenite is realized according to the following steps: Step one: the raw ore sand is slurried with water, the pulp concentration is controlled at 35%, then the coarse slag above 1mm is separated by a vibrating slag screen, the remaining ore sand is fed into a wet low-intensity magnetic separator, the magnetic field strength of the wet low-intensity magnetic separator is 160kA / m, the rotating speed is 0.628m / s, the iron concentrate and iron-removed ore sand are separated, the yield of the iron concentrate product is 5.51%, the content is 57.32wt% Step two: the iron-removed ore sand is fed into a wet vertical ring high-intensity magnetic separator, the magnetic field strength is 800kA / m, the titanium middlings and zirconium middlings are separated, the yield of the separated zirconium middlings is 20%, i.e. the amount of ore that needs to be dried is reduced to 74.49% through this step, saving the subsequent fuel cost.

[0020] Step three: the titanium middlings are fed into a belt filter, dried after filtering, and then transferred to a drying furnace by a belt conveyor, the moisture is dried to below 0.5% to obtain dried titanium middlings.

[0021] Step four: the dried titanium middlings are separated by a dry high-speed magnetic separator, the dry high-speed magnetic separator is preferably a double-layer permanent magnetic drum magnetic separator, a permanent magnetic drum is used, the upper layer is a low-intensity drum with a magnetic field strength of 160kA / m and a rotating speed of 1.0m / s, which further removes the strong magnetic iron in the titanium middlings, the lower layer is a strong magnetic drum with a magnetic field strength of 560kA / m and a rotating speed of 2.35m / s, two ore separation plates are arranged in the lower layer, this step can separate three products at the same time, which are titanium concentrate, iron-titanium middlings and zirconium middlings, the yield of the titanium concentrate is 54.37%, the content is 47.79wt%, trivalent iron the content is 15.68wt%.

[0022] Step five: the iron-rich titanium middlings are fed into a rotary kiln, the yield of the iron-rich titanium middlings that need to be reduced in this step is 10.12%, after being fully reduced in a reducing atmosphere, the iron concentrate, titanium concentrate and zirconium middlings are separated by the dry high-speed magnetic separator in step four, the yield of the separated titanium concentrate is 4.70%, trivalent iron The contents were 48.63 wt% and 9.08 wt%, respectively.

[0023] Example 1 shows that this process reduces the drying amount by 25.51 wt% and the amount of ore to be reduced and roasted by 13.63 wt% compared to the traditional roasting-magnetic separation process, thereby significantly reducing production costs.

[0024] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-cost beneficiation process for ilmenite mineralized by hematite alteration, characterized in that: Includes the following steps: Step 1: After adding water to the raw ore sand to make slurry until the slurry concentration reaches 20%~45%, use a slag screen to vibrate and coarse the ore sand. The screened ore sand is then fed into a wet weak magnetic separator to obtain iron-removed ore sand. Step 2: The iron ore sand is subjected to zirconium-titanium separation by a wet high-intensity magnetic separator to separate titanium middlings and zirconium middlings; Step 3: Filter and dry the titanium ore to obtain dried titanium ore; Step 4: The dried titanium middlings are fed into a dry high-speed magnetic separator to separate titanium concentrate, iron-rich titanium middlings, and zirconium middlings. Step 5: The iron-titanium middlings are reduced, roasted, and cooled, and then separated again by the dry high-speed magnetic separator to obtain iron concentrate, titanium concentrate, and zirconium middlings.

2. The low-cost beneficiation process for hematite-altered ilmenite according to claim 1, characterized in that: In step four, the dry high-speed magnetic separator is a permanent magnet drum separator with a drum rotation speed of 2.0 m / s to 6.0 m / s.

3. The low-cost beneficiation process for ilmenite with hematite mineralization and alteration according to claim 2, characterized in that: The permanent magnet drum separator has a double-layer structure. The upper layer is a weak magnetic drum with a magnetic field strength of 80kA / m to 240kA / m and a rotation speed of 0.8m / s to 1.5m / s, which removes the strongly magnetic iron from titanium middlings. The lower layer is a strong magnetic drum with a magnetic field strength of 480kA / m to 800kA / m and a rotation speed of 2m / s to 4m / s. The lower magnetic drum is equipped with two ore separating plates, which can simultaneously separate three products: titanium concentrate, iron-rich titanium middlings, and zirconium middlings.

4. The low-cost beneficiation process for hematite-altered ilmenite according to claim 1, characterized in that: The magnetic field strength of the wet weak magnetic separator in step one is 80kA / m to 240kA / m, and the rotation speed is 0.5m / s to 1m / s.

5. The low-cost beneficiation process for hematite-altered ilmenite according to claim 1, characterized in that: The magnetic field strength of the wet high-intensity magnetic separator in step two is 800kA / m to 1200kA / m.

6. The low-cost beneficiation process for hematite-altered ilmenite according to claim 1, characterized in that: In step three, the titanium middlings ore filtration method uses a belt filter to filter out the moisture. After filtration, the ore is transferred to a drying oven via a belt conveyor to dry the moisture content to below 0.5%, thus obtaining dried titanium middlings ore.

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