Non-equidistant spiral chute device and ilmenite separation method

Abstract

The invention discloses a non-equidistant spiral chute device for separating pyroxene peridotite type ilmenite, which comprises a rack and a spiral chute vertically arranged in the rack, and is characterized in that the screw pitch of the spiral chute is sequentially increased from top to bottom; the section shape of the spiral chute sequentially comprises a cubic parabolic arc, an elliptic arc and an arc from the outer edge to the center. The invention further discloses a separation method for separating ilmenite by using the non-equidistant spiral chute device. According to the non-equidistant spiral chute device disclosed by the invention, by adopting a non-equidistant pitch design, the pitch of the spiral chute is sequentially increased from top to bottom, and the section shape of the spiral is optimized, so that different water flow speeds and centrifugal force distribution areas are created, and the motion trails of olivine and ilmenite in the chute are changed; and turbulent flow and vortex are reduced, effective separation of olivine and ilmenite is achieved, and efficient recovery of ilmenite is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of ore dressing, and in particular relates to a spiral chute and an ilmenite separation method. Background Art

[0002] The physical and chemical properties of olivine-type ilmenite and its associated gangue minerals such as olivine are extremely similar. It is difficult to effectively separate ilmenite and olivine using existing process flow and equipment technology. For example, if conventional high-intensity magnetic separation technology is used to remove olivine, it is difficult to separate olivine from ilmenite by magnetic separation because the specific magnetic susceptibility of ilmenite and olivine is very close. And the conventional spiral chute gravity separation cannot achieve the ideal separation effect due to the fixed pitch-diameter ratio and cross-sectional shape of the conventional spiral chute, making it difficult to achieve the purpose of efficient enrichment of ilmenite. Therefore, this type of olivine-type ilmenite resources has not been effectively developed and utilized, and there has been a technical gap at home and abroad. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the shortcomings and defects mentioned in the above background technology, and provide a non-equidistant spiral chute device for sorting olivine-type ilmenite and a sorting method for olivine-type ilmenite, which can effectively separate olivine-type ilmenite from its associated gangue minerals such as olivine, and realize efficient recovery of olivine-type ilmenite.

[0004] In order to solve the above technical problems, the technical solution proposed by the present invention is: A non-equidistant spiral chute device for sorting olivine-type ilmenite comprises a frame and a spiral chute vertically arranged in the frame, wherein the pitch of the spiral chute increases from top to bottom, and the cross-sectional shape of the spiral chute comprises a cubic parabola arc, an elliptical arc, and a circular arc from the outer edge to the center.

[0005] In the present invention, the cross-sectional shape of the spiral chute refers to the cross-sectional shape of any longitudinal section passing through the center of the spiral. From the outer edge of the spiral chute to the center of the spiral chute, the cross-sectional shapes are cubic parabola arc, elliptical arc and circular arc respectively.

[0006] In the above-mentioned non-equidistant spiral chute device, preferably, the pitch of the spiral chute is 360-458mm.

[0007] In the above-mentioned non-equidistant spiral chute device, preferably, the distance-to-diameter ratio of the spiral chute increases from top to bottom, and the distance-to-diameter ratio is 0.6-0.8.

[0008] In the above non-equidistant spiral chute device, preferably, the olivine-type ilmenite is co-existing with olivine, the spiral chute is composed of 5 spirals connected up and down, and the pitch of the spiral chute is 375mm, 395mm, 410mm, and 435mm from top to bottom, and the pitch-to-diameter ratio of the spiral chute is 0.65-0.75. The spiral chute with the above structural form, combined with a specific cross-sectional shape, is more suitable for the separation of olivine and olivine-type ilmenite.

[0009] In the above non-equidistant spiral chute device, preferably, the width of each spiral of the spiral chute remains the same. The present invention does not change the cross-sectional width of each spiral, which can be better implemented in industrial production processes.

[0010] In the above non-equidistant spiral chute device, preferably, the cubic parabola arc satisfies the following equation: y=ax 3 , a is 0.5-1, x is 3-10, and the cubic parabola arc occupies 1 / 3-2 / 3 of the arc segment of the cross section, and more preferably 1 / 2. The proportion of the cubic parabola arc in the arc segment of the cross section refers to the proportion of the length of the cubic parabola arc in the total arc length of the cross section.

[0011] In the above non-equidistant spiral chute device, preferably, the elliptical arc satisfies the following parametric equation: x=acost, y=bsint, where t∈[0,π / 2], a value is 2-4, b value is 1-2, and the elliptical arc occupies 1 / 5-1 / 3 of the cross-sectional arc segment, and more preferably 1 / 4. The above t∈[0,π / 2] is an arc segment in the first quadrant. When specifically designed in a spiral chute, the direction of the arc segment can be changed so that its opening faces upward and better matches the cubic parabola arc and circular arc.

[0012] In the above non-equidistant spiral chute device, preferably, the arc satisfies the following parametric equation: x=a+rcost, y=b+rsint, where t∈[0,π / 2], a value is 1-10, b value is 1-10, r value is 1-8, and the arc occupies 1 / 5-1 / 3 of the cross-sectional arc segment, and more preferably 1 / 4. The above t∈[0,π / 2] is the arc segment of the first quadrant. When it is specifically designed in the spiral chute, the direction of the arc segment can be changed so that its opening faces upward and better matches the elliptical arc.

[0013] In the present invention, by optimizing the arc forms of cubic parabola arcs, elliptical arcs, and circular arcs, and cooperating with the optimized selection of arc segment ratios, the pressure distribution of the water flow is made more uniform, which helps to maintain the stability of the water film, thereby reducing the formation of vortices, providing an ideal water film environment for the effective separation of olivine and pyroxenite-type ilmenite, and is beneficial to the separation of olivine and pyroxenite-type ilmenite.

[0014] In the above-mentioned non-equidistant spiral chute device, preferably, the surface of the sorting trough body of the spiral chute is provided with a silicon carbide coating.

[0015] As a general technical concept, the present invention also provides a separation method for ilmenite using the above-mentioned non-equidistant spiral chute device, comprising the following steps: (1) Grinding and weak magnetic separation of olivine ilmenite to obtain pretreated raw materials; (2) The pretreated raw material is subjected to gravity separation by using the non-equidistant spiral chute device to separate the olivine-type ilmenite and olivine, that is, to separate the olivine-type ilmenite.

[0016] Olivine usually has a relatively small density. In a spiral chute, due to the characteristics of water flow velocity and centrifugal force distribution, it tends to be in the upper area of ​​the spiral chute, and the water flow velocity can carry olivine to move downward quickly along the outer side of the spiral chute. Its movement trajectory is relatively close to the outer side and upper layer of the chute, and its movement speed is relatively fast. The density of olivine-type ilmenite is relatively large. In a spiral chute, ilmenite will gradually gather toward the inner wall and lower layer of the spiral chute. Its movement trajectory is more inclined to the inner side and lower layer of the spiral chute, and its movement speed is slower than that of olivine. This difference in movement trajectory causes olivine and olivine-type ilmenite to form obvious stratification at the outlet of the spiral chute. Olivine will first flow out from the outer side or upper layer of the spiral chute because its movement trajectory is close to the outer side and upper layer; while olivine-type ilmenite will flow out from the inner side or lower layer of the chute because it moves toward the inner side and lower layer. By properly setting the outlet structure of the spiral chute, olivine and pyroxenite-type ilmenite can be collected separately, thus achieving effective separation of the two minerals. In this way, the purpose of ore separation is achieved by utilizing the difference in mineral density and the special water flow velocity and centrifugal force distribution environment created by the spiral chute.

[0017] In order to better separate olivine-type ilmenite and olivine, the present invention develops a non-equidistant spiral chute based on the characteristics of gangue minerals similar to olivine-type ilmenite mineralization properties, such as high olivine content, many weakly magnetic minerals, easy mudification, and low distribution rate of titanium in ilmenite. By reasonably distributing the pitch and pitch-to-diameter ratio and optimizing the cross-sectional shape of the spiral, different water flow velocities and centrifugal force distribution areas are created, which changes the movement trajectories of olivine and olivine-type ilmenite in the chute, reduces the generation of turbulence and vortices, achieves effective separation of olivine and olivine-type ilmenite, and achieves efficient recovery of ilmenite.

[0018] Specifically, the non-equidistant spiral chute of the present invention is a new type of flow film sorting equipment. By cleverly adjusting the pitch, the minimum pitch is 360mm, the maximum pitch is 458mm, and the corresponding pitch-to-diameter ratio is about 0.6 and 0.8, respectively, thus creating different water flow speeds and centrifugal force distribution areas, which changes the movement trajectory of olivine and olivine pyroxene type ilmenite in the chute. Through the analysis and simulation of the water flow characteristics in the chute, the cross-section design of the sorting chute body is composed of a combination of various geometric shapes such as circles, ellipses, and cubic parabolas, which optimizes the shape of the chute sorting surface and the water film distribution. This optimization makes the water flow more stable and uniform, reduces the generation of turbulence and vortices, and provides an ideal water film environment for the effective separation of olivine and olivine pyroxene type ilmenite. Secondly, the spiral chute body uses advanced polymer materials and silicon carbide surface coating technology. The chute body is not only wear-resistant and corrosion-resistant, but also reduces the friction and adhesion between the ore and the inner wall, improves the accuracy of sorting, and thus improves the accuracy and efficiency of sorting.

[0019] More specifically, in the separation process of olivine and pyroxenite-type ilmenite, the stability of the water film is crucial. By reducing the generation of turbulence and vortex, the spiral chute can provide a more ideal water film environment to ensure the effective flotation and separation of mineral particles in the water flow. The steady water flow can effectively promote the stratification of mineral particles of different densities in water according to their physical properties, thereby improving the efficiency of separation. In the non-equidistant spiral chute of the present invention, the pitch and pitch-to-diameter ratio of the spiral chute are important factors affecting the water flow characteristics. Reasonable pitch design can regulate the flow speed and flow rate of the water flow in the spiral trough. Too large pitch may cause uneven water flow, while too small pitch may increase flow resistance. Appropriate pitch-to-diameter ratio can ensure the smooth flow of water in the trough, making the flow state more ideal, and helping to further optimize the flow path of the water flow. More importantly, the cross-sectional shape of the spiral chute also has an important influence on the sorting effect of olivine and pyroxenite-type ilmenite. The circular cross-section can provide a uniform flow velocity distribution, reduce the influence of the boundary layer, and thus reduce the generation of turbulence. The elliptical cross section can achieve a more streamlined water flow, reduce flow resistance, and improve the stability of the water flow. The cubic parabola cross section can better guide the water flow, keep the fluid smooth when changing direction, reduce the sharp change in flow velocity, and reduce the possibility of turbulence formation. By accurately controlling the cross-sectional shape of the spiral chute, the turbulence and vortex generated by the fluid during the flow process can be effectively reduced. The optimized cross-sectional shape ensures the continuity of the water flow in the entire chute, reduces the separation phenomenon of the fluid in the turning or transition area, and thus reduces the generation of local turbulence. Reasonable geometric shape design makes the pressure distribution of the water flow more uniform, helps to maintain the stability of the water film, and thus reduces the formation of vortices. The present invention can significantly improve the characteristics of the water flow, reduce the generation of turbulence and vortexes, and provide an ideal water film environment for the effective separation of olivine and olivine pyroxene type ilmenite by reasonably combining the cross-sectional shape of the spiral chute with the pitch and pitch-to-diameter ratio. This optimized design not only improves the efficiency of mineral separation, but also provides a theoretical basis and practical guidance for subsequent industrial applications.

[0020] The specific cross-sectional shape, spiral pitch and pitch-to-diameter ratio of the spiral chute used in the present invention are particularly suitable for the separation of olivine and olivine-type ilmenite, and can ensure the separation effect of the two.

[0021] Compared with the prior art, the advantages of the present invention are: The non-equidistant spiral chute device of the present invention adopts a non-equidistant pitch design, so that the pitch of the spiral chute increases from top to bottom, and optimizes the cross-sectional shape of the spiral, thereby creating different water flow velocities and centrifugal force distribution areas, which changes the movement trajectories of olivine and ilmenite in the chute, reduces the generation of turbulence and vortices, realizes the effective separation of olivine and ilmenite, and realizes the efficient recovery of ilmenite.

[0022] The non-equidistant spiral chute device of the present invention is used to re-select olivine-type ilmenite, and the content of the target mineral ilmenite is increased by 55.84% compared with the case where only the strong magnetic separation technology is used. 2 The grade was increased by 28.07% compared with the case when only strong magnetic separation technology was used, while the contents of olivine, titanopyroxene and titanomagnetite, the main interfering minerals in flotation, were also greatly reduced compared with the strong magnetic separation technology, decreasing by 32.99%, 38.42% and 36.64% respectively. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 Schematic diagram of the structure of the non-equidistant spiral chute device in the embodiment.

[0025] Legend 1. Feed inlet; 2. Water hopper; 3. Spiral chute; 4. Frame; 5. Discharge outlet. DETAILED DESCRIPTION

[0026] In order to facilitate the understanding of the present invention, the present invention will be described more comprehensively and meticulously below in conjunction with the accompanying drawings and preferred embodiments of the present invention, but the protection scope of the present invention is not limited to the following specific embodiments.

[0027] It should be noted that when an element is described as being "fixed, fixed, connected or connected to" another element, it can be directly fixed, fixed, connected or connected to the other element, or it can be indirectly fixed, fixed, connected or connected to the other element through other intermediate connectors.

[0028] Unless otherwise defined, all the professional terms used below have the same meanings as those generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the scope of protection of the present invention.

[0029] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0030] Example: like Figure 1As shown, the non-equidistant spiral chute device of this embodiment includes a frame 4 and a spiral chute 3 vertically arranged in the frame 4, the pitch of the spiral chute 3 increases from top to bottom, and the pitch-to-diameter ratio increases from top to bottom. The spiral chute 3 is composed of 5 spirals connected up and down, and the pitch is 375mm, 395mm, 410mm, and 435mm from top to bottom, and the pitch-to-diameter ratio is 0.65-0.75.

[0031] The cross-sectional shape of the spiral chute 3 includes a cubic parabola arc, an elliptical arc, and a circular arc from the outer edge to the center. The cubic parabola arc satisfies the following equation: y=ax 3 , a is 2.6, x is 3-10, and the cubic parabola arc occupies 1 / 2 of the cross-sectional arc segment. The elliptical arc satisfies the following parametric equation: x=acost, y=bsint, where t∈[0,π / 2], a is 2.6, b is 1.8, and the elliptical arc occupies 1 / 4 of the cross-sectional arc segment. The circular arc satisfies the following parametric equation: x=a+rcost, y=b+rsint, where t∈[0,π / 2], a is 2.6, b is 1.8, r is 6, and the circular arc occupies 1 / 4 of the cross-sectional arc segment.

[0032] More specifically, the non-equidistant spiral chute device consists of the following main parts: The feed port 1 and the water hopper 2 are used to evenly feed the mineral materials to be sorted and water into the spiral chute 3.

[0033] Spiral chute 3: It is mainly divided into multiple sections and adopts a spiral design. The pitch of each section is different to meet the sorting needs of different minerals.

[0034] Frame 4: The framework and support of the entire device, ensuring the stability and safety of the spiral trough.

[0035] Discharge port 5: used to collect sorted minerals, usually collected in layers according to the specific gravity and flow characteristics of the minerals.

[0036] The design of the non-equidistant spiral chute in this embodiment combines the optimization of the pitch, pitch-to-diameter ratio and cross-sectional shape, aiming to improve the efficiency and effect of mineral separation. Through reasonable structural design, the state of water flow can be effectively controlled, the generation of turbulence and vortex can be reduced, and a stable water film environment can be provided for separation, thereby optimizing the separation process of minerals such as olivine and pyroxenite-type ilmenite.

[0037] The present embodiment uses the above-mentioned non-equidistant spiral chute device to separate ilmenite, and the separation method comprises the following steps: (1) Grinding and weak magnetic separation of olivine ilmenite to obtain pretreated raw materials; (2) The pretreated raw materials are re-selected by using a non-equidistant spiral chute device to separate the olivine-type ilmenite and olivine, that is, to separate the olivine-type ilmenite.

[0038] For comparison, a conventional spiral chute device, a non-equidistant spiral chute device in this embodiment, and a conventional strong magnetic separation were used to treat a olivine-type ilmenite (iron tailings) in Panxi. The pitch of the conventional spiral chute device, the spiral outer diameter is 600 mm, the pitch is 360 mm, the pitch-to-diameter ratio is 0.6, and the cross-sectional shape of the separation tank body is a cubic parabola. The strong magnetic separation uses a domestic vertical ring strong magnetic separator. Under the optimal process parameter conditions, the magnetic field intensity is 5000-9000 Gauss, and the rotating ring speed is 3 rpm. At the same time, in order to prove the influence of the pitch and pitch-to-diameter ratio of the non-equidistant spiral chute device of this embodiment and the influence of the cross-sectional shape, comparative examples 1-3 are also added to sort and treat a olivine-type ilmenite (iron tailings) in Panxi. The spiral chute device of comparative example 1, the cross-sectional shape of the spiral chute is the same as that of the embodiment, but the pitch and pitch-to-diameter ratio are fixed (the pitch is 360 mm, and the pitch-to-diameter ratio is 0.6). The spiral chute device of comparative example 2 has the same pitch and pitch-to-diameter ratio as the embodiment, and the cross-sectional shape of the spiral chute is the cubic parabola arc in the embodiment. The spiral chute device of comparative example 3 has the same pitch and pitch-to-diameter ratio as the embodiment, and the cross-sectional shape of the spiral chute is the cubic parabola arc and circular arc in the embodiment, and the arc segments of the two are in a ratio of 1:1.

[0039] The composition and content of a olivine-type ilmenite in Panxi are shown in Table 1. The metal minerals in the sample are mainly ilmenite and titanomagnetite, followed by hematite and limonite; the metal sulfide is mainly pyrrhotite, with occasional pyrite, chalcopyrite and cobalt-pentlandite scattered; the gangue minerals are mainly titanopyroxene, titanophene, plagioclase and olivine, followed by edingite, biotite, sericite and chlorite, and trace minerals include serpentine, sphene, ilmenite, magnesia spinel, apatite and zoisite.

[0040] By using the non-equidistant spiral chute device, high-intensity magnetic separation, conventional spiral chute device of the present embodiment and the spiral chute device in Comparative Examples 1-3 using a one-roughing, two-sweeping and one-fine gravity separation technology, it was found by comparing the separation effects that the ilmenite grade obtained by using the non-equidistant spiral chute device of the present embodiment was significantly improved, and the olivine content in the concentrate was reduced from 42.59% to 28.54%. The results are shown in Table 2 below.

[0041] Table 1: Chemical multi-element analysis results of a pyroxenite-type ilmenite (iron tailings) in Panxi / %

[0042] Table 2: Sorting test results of different sorting devices / %

Claims

1. A non-equidistant spiral chute device for separating olivine-type ilmenite, comprising a frame and a spiral chute vertically arranged in the frame, characterized in that: The pitch of the spiral chute increases from top to bottom, and the cross-sectional shape of the spiral chute includes a cubic parabola arc, an elliptical arc, and a circular arc from the outer edge to the center.

2. The non-equidistant spiral chute device according to claim 1, characterized in that: The pitch of the spiral chute is 360-458 mm.

3. The non-equidistant spiral chute device according to claim 1, characterized in that: The distance-to-diameter ratio of the spiral chute increases from top to bottom, and the distance-to-diameter ratio is 0.6-0.

8.

4. The non-equidistant spiral chute device according to claim 1, characterized in that: The olivine-type ilmenite is co-existing with olivine, and the spiral chute is composed of 5 spirals connected up and down, and the pitches of the spiral chute are 375mm, 395mm, 410mm, and 435mm from top to bottom, respectively, and the pitch-to-diameter ratio of the spiral chute is 0.65-0.

75.

5. The non-equidistant spiral chute device according to claim 1, characterized in that: The width of each spiral of the spiral chute remains the same.

6. The non-equidistant spiral chute device according to any one of claims 1 to 5, characterized in that: The cubic parabola arc satisfies the following equation: y=ax 3 , a is 0.5-1, x is 3-10, and the cubic parabola arc occupies 1 / 3-2 / 3 of the arc segment of the cross section.

7. The non-equidistant spiral chute device according to any one of claims 1 to 5, characterized in that: The elliptical arc satisfies the following parametric equation: x=acost, y=bsint, where t∈[0,π / 2], a value is 2-4, b value is 1-2, and the elliptical arc occupies 1 / 5-1 / 3 of the arc segment of the cross section.

8. The non-equidistant spiral chute device according to any one of claims 1 to 5, characterized in that: The arc satisfies the following parametric equation: x=a+rcost, y=b+rsint, where t∈[0,π / 2], a value is 1-10, b value is 1-10, r value is 1-8, and the arc occupies 1 / 5-1 / 3 of the arc segment of the cross section.

9. The non-equidistant spiral chute device according to any one of claims 1 to 5, characterized in that: The surface of the sorting tank body of the spiral chute is provided with a silicon carbide coating.

10. A method for separating ilmenite using the non-equidistant spiral chute device according to any one of claims 1 to 9, characterized in that: The following steps are involved: (1) Grinding and weak magnetic separation of olivine ilmenite to remove iron, to obtain pretreated raw materials; (2) The pretreated raw material is subjected to gravity separation by using the non-equidistant spiral chute device to separate the olivine-type ilmenite and olivine, that is, to separate the olivine-type ilmenite.

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