A beneficiation method for fine-grained beach placer and its application

Abstract

The present invention relates to the technical field of ore dressing, and specifically, to a method for dressing fine-grained beach placer ores and its application. After the pulp is subjected to wet magnetic roughing, wet magnetic roughing concentrate and wet magnetic roughing tailings are obtained; the wet magnetic roughing tailings are subjected to wet magnetic scavenging to obtain wet magnetic scavenging concentrate; the wet magnetic roughing concentrate and the wet magnetic scavenging concentrate are mixed and subjected to cyclone classification to obtain coarse-grained wet magnetic material and fine-grained wet magnetic material; the coarse-grained wet magnetic material is subjected to dry magnetic roughing to obtain dry magnetic roughing concentrate and dry magnetic roughing tailings; the dry magnetic roughing tailings are subjected to dry magnetic scavenging to obtain dry magnetic scavenging concentrate; the dry magnetic scavenging concentrate is subjected to electrostatic separation to obtain electrostatic separation concentrate; the electrostatic separation concentrate and the dry magnetic roughing concentrate are mixed to obtain coarse-grained titanium concentrate; the fine-grained wet magnetic material is subjected to wet magnetic cleaning to obtain wet magnetic cleaning concentrate and wet magnetic cleaning tailings; the wet magnetic cleaning tailings are subjected to gravity separation scavenging to obtain gravity separation scavenging concentrate, and the wet magnetic cleaning concentrate and the gravity separation scavenging concentrate are mixed to obtain fine-grained titanium concentrate. This method can obtain coarse-grained titanium concentrate and fine-grained titanium concentrate with different particle sizes.

Description

Technical Field

[0001] The present invention relates to the technical field of ore dressing, and in particular, to an ore dressing method for fine-grained beach placer and its application. Background Art

[0002] Beach placer has the advantages of easy mining, low cost, high comprehensive utilization value, etc. At the same time, compared with inland rock ore, beach ilmenite placer has a higher titanium dioxide content and a lower impurity content. Therefore, the sorted beach placer is the main raw material for preparing titanium-rich materials, and high-quality titanium-rich materials supply the production needs of preparing titanium tetrachloride by the fluidized bed chlorination method.

[0003] The molten salt chlorination has a higher tolerance for fine particle size and can still ensure normal production in the case of fine particle size. However, at present, the fluidized bed chlorination production technology, titanium-rich material production process and equipment all require that the raw material particle size should not be too fine, and the proportion of -160 mesh should be controlled at a low level. Fine-grained titanium concentrate not only causes waste of resources, but also greatly affects the continuity and safety of normal industrial production.

[0004] With the gradual development and utilization of beach placer, as well as the substantial increase in the production of titanium dioxide and titanium sponge, the huge annual production of titanium tetrachloride also makes high-quality beach placer tend to decrease. The reduction in the quality of beach placer is not only reflected in the increase in impurity content, but also the particle size gradually becomes finer. The proportion of -160 mesh in heavy mineral sand can reach 20%-40%, or even tend to be higher, resulting in that the conventional all-grain-size separation method is not conducive to the downstream production needs.

[0005] Therefore, it is of great significance to provide a suitable classification and separation method to produce products with different particle sizes, which is more suitable for the comprehensive utilization of beach placer.

[0006] In view of this, the present invention is specifically proposed. Summary of the Invention

[0007] The first object of the present invention is to provide an ore dressing method for fine-grained beach placer, which can obtain coarse-grained titanium concentrate and fine-grained titanium concentrate with different particle sizes. The coarse-grained titanium concentrate can be used as the raw material for producing titanium tetrachloride by the fluidized bed chlorination method, and the fine-grained titanium concentrate can be used as the raw material for producing titanium tetrachloride by the molten salt chlorination method, with high resource utilization rate.

[0008] The second object of the present invention is to provide the application of the ore dressing method for fine-grained beach placer in the production of titanium-rich materials and titanium tetrachloride.

[0009] In order to achieve the above objects of the present invention, the following technical solutions are specifically adopted:

[0010] The present invention provides an ore dressing method for fine-grained beach placer, including the following steps:

[0011] (a) After the pulp containing fine-grained beach placer is rougher-selected by wet magnetic separation, a wet roughing concentrate and a wet roughing tailing are obtained; after the wet roughing tailing is wet magnetic scavenged, a wet magnetic scavenging concentrate is obtained;

[0012] Among them, the proportion of minerals with a particle size below 160 mesh in the fine-grained beach placer is 15% - 40%;

[0013] (b) The wet roughing concentrate and the wet magnetic scavenging concentrate are mixed and dried, and then subjected to cyclone classification to obtain a coarse-grained wet magnetic material and a fine-grained wet magnetic material;

[0014] (c) The coarse-grained wet magnetic material is screened and then subjected to dry magnetic roughing to obtain a dry roughing concentrate and a dry roughing tailing; the dry roughing tailing is dry magnetic scavenged to obtain a dry magnetic scavenging concentrate;

[0015] (d) After the dry magnetic scavenging concentrate is subjected to electrostatic separation, an electrostatic separation concentrate is obtained; the electrostatic separation concentrate and the dry roughing concentrate obtained in step (c) are mixed to obtain a coarse-grained titanium concentrate with a particle size of 40 - 160 mesh;

[0016] (e) The fine-grained wet magnetic material obtained in step (b) is formulated into a pulp and then subjected to wet magnetic cleaning to obtain a wet magnetic cleaning concentrate and a wet magnetic cleaning tailing; the wet magnetic cleaning tailing is re-selected and scavenged to obtain a re-selection scavenging concentrate; the wet magnetic cleaning concentrate and the re-selection scavenging concentrate are mixed and dried to obtain a fine-grained titanium concentrate with a particle size of 100 - 400 mesh.

[0017] The present invention also provides an application of the beneficiation method of the fine-grained beach placer as described above in the production of titanium-rich materials and titanium tetrachloride.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] (1) The beneficiation method of the fine-grained beach placer provided by the present invention can obtain two different particle-size grades of titanium concentrates, namely, a coarse-grained titanium concentrate with a particle size of 40 - 160 mesh and a fine-grained titanium concentrate with a particle size of 100 - 400 mesh, which can meet the requirement that the particle size of the raw material for fluidized bed chlorination to produce titanium tetrachloride cannot be too fine.

[0020] (2) The beneficiation method of the fine-grained beach placer provided by the present invention has the advantages of simple process, easy implementation, high resource recovery rate, and high titanium recovery rate.

[0021] (3) The beneficiation method of the fine-grained beach placer provided by the present invention reduces the screening difficulty of coarse-grained and fine-grained products. Description of the Drawings

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0023] Figure 1 It is a schematic process flow diagram of the beneficiation method for fine-grained beach placer provided by the present invention. Specific embodiments

[0024] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the drawings and specific embodiments. However, those skilled in the art will understand that the following described embodiments are some embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention. For those conditions not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments not specified by the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0025] In the first aspect, the present invention provides a beneficiation method for fine-grained beach placer, as Figure 1 shown in the schematic process flow diagram of the beneficiation method for fine-grained beach placer provided by the present invention, which specifically includes the following steps:

[0026] (a) After the pulp containing fine-grained beach placer is subjected to rough beneficiation by wet magnetic separation, a wet rough concentrate and a wet rough tailing are obtained; after the wet rough tailing is subjected to wet magnetic scavenging (i.e., wet magnetic separation scavenging), a wet magnetic scavenging concentrate is obtained (and a wet magnetic scavenging tailing is also obtained, which is discarded).

[0027] Among them, most of the gangue components in the minerals are removed during the rough beneficiation by wet magnetic separation, and the titanium concentrate, leucoxene, and rutile components in the wet rough tailing are recovered during the wet magnetic scavenging. At the same time, the overall wet magnetic separation avoids the loss of fine-grained minerals.

[0028] Among them, the proportion (mass percentage) of minerals with a particle size of less than 160 mesh (i.e., less than or equal to 96 microns) in the fine-grained beach placer is 15% - 40%.

[0029] In some specific embodiments of the present invention, the mass fraction of titanium dioxide in the fine-grained beach placer is 30% - 45%.

[0030] The present invention can ensure the titanium recovery rate by first performing wet magnetic separation on fine-grained beach placer minerals.

[0031] (b) Mix and dry the wet roughing concentrate obtained in step (a) and the wet magnetic scavenging concentrate obtained in step (a), and then perform cyclone classification to obtain coarse-grained wet magnetic material and fine-grained wet magnetic material.

[0032] The present invention reduces the screening difficulty of coarse-grained and fine-grained products by adopting cyclone classification instead of conventional screening.

[0033] Specifically, conventional dry screening cannot be industrialized on a large scale when screening less than 100 mesh, and conventional wet screening also needs to introduce high-frequency vibration to ensure continuous production during 160-mesh industrial production. Therefore, cyclone classification can replace screening to reduce the screening difficulty.

[0034] (c) Screen the coarse-grained wet magnetic material obtained in step (b) and then perform dry magnetic separation roughing to obtain dry magnetic separation roughing concentrate and dry magnetic separation roughing tailings; after dry magnetic scavenging of the dry magnetic separation roughing tailings, dry magnetic scavenging concentrate is obtained (dry magnetic scavenging tailings are also obtained and discarded).

[0035] Among them, performing dry magnetic separation roughing on the coarse-grained wet magnetic material mainly further removes impurities in the coarse-grained wet magnetic material.

[0036] According to the characteristics of high weathering and high silicon content of beach placer minerals, the present invention screens the coarse-grained wet magnetic material obtained in step (b) to remove large-particle impurities such as quartz and iron oxide. While reducing the impurity content, it also reduces the subsequent separation difficulty.

[0037] (d) After performing electrostatic separation on the dry magnetic scavenging concentrate obtained in step (c), electrostatic separation concentrate is obtained (electrostatic separation middlings and electrostatic separation tailings are also obtained, where the electrostatic separation tailings are discarded, and the electrostatic separation middlings can be recycled and mixed with the dry magnetic scavenging concentrate of the next batch and then subjected to electrostatic separation again).

[0038] The impurity content in the dry magnetic separation roughing tailings is relatively high, and it cannot be completely removed only by magnetic scavenging. Therefore, electrostatic separation is performed to enhance its impurity removal ability and ensure the grade and recovery rate of titanium concentrate recovered from the dry magnetic separation roughing tailings.

[0039] Then mix the electrostatic separation concentrate with the dry magnetic separation roughing concentrate obtained in step (c) to obtain coarse-grained titanium concentrate with a particle size of 40 - 160 mesh.

[0040] (e) Prepare the fine-grained wet magnetic material obtained in step (b) into a pulp and then perform wet magnetic separation cleaning (i.e., wet magnetic separation cleaning) to obtain wet magnetic separation cleaning concentrate and wet magnetic separation cleaning tailings.

[0041] Then, the wet magnetic separation tailings are subjected to gravity separation scavenging to obtain gravity separation scavenging concentrate (and gravity separation scavenging tailings are also obtained and discarded), and then the wet magnetic separation concentrate is mixed with the gravity separation scavenging concentrate and dried to obtain fine-grained titanium concentrate with a particle size of 100-400 mesh.

[0042] Based on the characteristics that leucoxene and rutile in beach placer deposits widely exist in fine-grained fractions, after formulating the fine-grained wet magnetic material obtained in step (b) into pulp and conducting wet magnetic separation, gravity separation scavenging is further carried out, which further improves the comprehensive recovery rate of titanium products.

[0043] Specifically, the fine-grained wet magnetic material has a relatively fine particle size and is not suitable for dry magnetic separation, so wet magnetic separation is used for further impurity removal; in addition to conventional ilmenite in the fine-grained titanium dioxide in the wet magnetic separation tailings, it also contains leucoxene and rutile components. Leucoxene and rutile have weak magnetism and are not suitable for magnetic separation scavenging, so gravity separation is selected to recover titanium dioxide to ensure the overall titanium recovery rate.

[0044] Among them, the method of wet magnetic separation - cyclone classification is adopted. First, wet magnetic separation is used to remove gangue and other non-magnetic components, while ensuring a high titanium recovery rate. After drying, cyclone classification reduces the classification difficulty. Then, the obtained coarse-grained fraction is subjected to dry magnetic separation - electrostatic separation, and the fine-grained fraction is subjected to wet magnetic separation, and two high-quality products with different particle size ranges can be obtained. According to the characteristics that the separation and enrichment of coarse and fine-grained fractions in beach placer deposits can supply fluidized bed chlorination and molten salt chlorination respectively, the present invention proposes to distinguish the fine-grained beach placer deposits into coarse and fine-grained fractions and conduct separation respectively to obtain downstream products suitable for each.

[0045] The present invention conducts wet magnetic separation and cyclone classification on fine-grained beach ilmenite sand ore (-160 mesh accounts for 15%-40%, and the titanium dioxide content is 30%-45%), and then conducts dry magnetic separation - electrostatic separation and wet magnetic separation on the coarse and fine-grained fractions respectively, and two different particle size fractions of titanium concentrate products can be obtained.

[0046] The beneficiation method for fine-grained beach placer deposits provided by the present invention also has the advantages of simple process, easy implementation, high resource recovery rate, etc.

[0047] Preferably, in step (a), the solid content of the pulp containing fine-grained beach placer deposits is 20%-30%; including but not limited to any point value of 22%, 24%, 25%, 27%, 29% or the range value between any two of them.

[0048] Adopting the solid content within the above range can not only ensure the separation effect but also obtain a higher production capacity.

[0049] In some specific embodiments of the present invention, the method for preparing the pulp containing fine-grained beach placer includes: washing, de-sliming, and thickening (i.e., concentrating) the fine-grained beach placer in sequence to obtain a pulp with a solid content of 20% to 30%. It can be understood that if the solid content after thickening is higher than 30%, it can be diluted to the required solid content by adding water.

[0050] Preferably, in step (a), the magnetic field intensity of the rough wet magnetic separation is 4500 - 6000 GS, including but not limited to the point value of any one of 4700 GS, 4900 GS, 5000 GS, 5300 GS, 5500 GS, 5800 GS or the range value between any two of them.

[0051] With the magnetic field intensity within the above range, both the recovery rate and the titanium grade can be improved. According to the characteristics of beach placer, if the magnetic field intensity is too low, the tailing yield will be too large, that is, most of the titanium concentrate enters the tailings, resulting in a decrease in the overall recovery rate; while if the magnetic field intensity is too high, the concentrate yield will be too large, that is, some gangue impurity components enter the concentrate, resulting in too low titanium grade of the concentrate.

[0052] In some specific embodiments of the present invention, an electromagnetic magnetic separator is used for the rough wet magnetic separation.

[0053] Preferably, in step (a), the magnetic separation intensity of the wet magnetic scavenging is 10000 - 12000 GS, including but not limited to the point value of any one of 10500 GS, 11000 GS, 11500 GS or the range value between any two of them.

[0054] Preferably, in step (b), the drying temperature is 550 - 700 °C, including but not limited to the point value of any one of 570 °C, 600 °C, 630 °C, 650 °C, 680 °C or the range value between any two of them.

[0055] The drying time is 10 - 60 min, including but not limited to the point value of any one of 20 min, 30 min, 40 min, 50 min or the range value between any two of them.

[0056] In some specific embodiments of the present invention, the drying is carried out in a drying kiln. Preferably, after the mixing, concentration and dehydration are carried out first, and then the drying is carried out.

[0057] Preferably, in step (b), the particle size of the coarse-grained wet magnetic material is greater than 160 mesh (i.e., the particle size is greater than 96 microns), and the particle size of the fine-grained wet magnetic material is less than 100 mesh (i.e., the particle size is less than 150 microns).

[0058] It is understandable that during the cyclone separation process, it is impossible to ensure a certain mesh number as the boundary, so there is an overlapping range in the particle size intervals of the coarse-grained wet magnetic material and the fine-grained wet magnetic material.

[0059] Preferably, in step (c), the mesh number of the sieve used for screening is 40 - 60 meshes, such as 50 meshes.

[0060] Before the dry magnetic separation roughing, the coarse-grained wet magnetic material is subjected to vibrating screening to remove impurities with larger particle sizes.

[0061] Preferably, in step (c), the magnetic separation intensity of the dry magnetic separation roughing is 7500 - 9000 GS, including but not limited to the point value of any one of 7800 GS, 8000 GS, 8300 GS, 8500 GS, 8800 GS or the range value between any two of them.

[0062] Preferably, in step (c), the magnetic field intensity of the dry magnetic scavenging is 8000 - 9500 GS, including but not limited to the point value of any one of 8300 GS, 8500 GS, 8800 GS, 9000 GS, 9300 GS or the range value between any two of them.

[0063] Preferably, in step (d), the voltage of the electrostatic separation is 18000 - 22000 V, including but not limited to the point value of any one of 19000 V, 20000 V, 21000 V or the range value between any two of them.

[0064] Adopting the electrostatic separation voltage within the above range can not only improve the titanium recovery rate but also ensure a relatively high titanium grade.

[0065] In some specific embodiments of the present invention, in step (d), the heating temperature of the electrostatic separation is 110 - 150 °C, including but not limited to the point value of any one of 120 °C, 130 °C, 140 °C or the range value between any two of them.

[0066] Preferably, in step (e), the magnetic field intensity of the wet magnetic concentration is 6000 - 8000 GS, including but not limited to the point value of any one of 6300 GS, 6500 GS, 6800 GS, 7000 GS, 7300 GS, 7500 GS, 7800 GS or the range value between any two of them.

[0067] In some specific embodiments of the present invention, in step (e), a dehydration step is further included before drying.

[0068] Preferably, in step (e), the re-election scavenging is carried out using a shaking table (i.e., a shaking table device), the stroke of the shaking table is 10-20 mm, including but not limited to the point value of any one of 12 mm, 14 mm, 15 mm, 17 mm, 19 mm or the range value between any two; the stroke frequency of the shaking table is 100-250 times / min, including but not limited to the point value of any one of 120 times / min, 150 times / min, 180 times / min, 200 times / min, 230 times / min or the range value between any two.

[0069] In a second aspect, the present invention provides the application of the beneficiation method of the fine-grained beach placer described above in the production of titanium-rich materials and titanium tetrachloride.

[0070] Among them, the production method of the titanium tetrachloride includes the fluidized bed chlorination method and the molten salt chlorination method.

[0071] The following will describe in detail the implementation schemes of the present invention in combination with embodiments. However, those skilled in the art will understand that the following embodiments are only used to illustrate the present invention and should not be regarded as limiting the scope of the present invention. For those not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. For the reagents or instruments not specified in the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0072] The titanium grade of the fine-grained beach placer used in each of the following embodiments of the present invention is 37.10%, and the proportion (mass percentage) of minerals with -160 mesh (i.e., particle size less than or equal to 96 microns) is 19.57%.

[0073] Example 1

[0074] The beneficiation method of the fine-grained beach placer provided in this embodiment includes the following steps:

[0075] The fine-grained beach placer is deslimed by a hydrocyclone and classified by a spiral classifier, and after thickening, it is formulated into a slurry with a solid content of 20%. Subsequently, the slurry is subjected to rough wet magnetic separation at a low magnetic field intensity, where the magnetic field intensity is set to 5000 GS, to obtain a rough wet magnetic separation concentrate and a rough wet magnetic separation tailing.

[0076] The rough wet magnetic separation tailing is subjected to wet magnetic scavenging at a high magnetic field intensity, where the magnetic field intensity of the wet magnetic scavenging is set to 10000 GS, to obtain a wet magnetic scavenging concentrate.

[0077] Mix and concentrate the wet roughing concentrate and wet magnetic scavenging concentrate obtained above for dehydration, and then place them in a drying kiln for drying, where the drying temperature is 600 °C and the drying time is 20 min; then perform cyclone classification on the dried mixed ore to obtain coarse-grained wet magnetic material and fine-grained wet magnetic material. Among them, the particle size of the coarse-grained wet magnetic material is greater than 160 mesh (i.e., the particle size is greater than 96 μm); the particle size of the fine-grained wet magnetic material is less than 100 mesh (i.e., the particle size is less than 150 μm).

[0078] Screen the above-prepared coarse-grained wet magnetic material through a 40-mesh sieve, and perform dry magnetic separation roughing on the undersize at a high magnetic field intensity. The magnetic field intensity of the dry magnetic separation roughing is 8000 GS to obtain dry roughing concentrate and dry roughing tailings. Perform dry magnetic scavenging on the dry roughing tailings at a high magnetic field intensity. The magnetic field intensity of the dry magnetic scavenging is 8000 GS to obtain dry magnetic scavenging concentrate.

[0079] Heat the above-obtained dry magnetic scavenging concentrate to 150 °C and then perform electrostatic separation. The electrostatic separation voltage is 20000 V to obtain electrostatic separation concentrate and electrostatic separation middlings. After mixing the electrostatic separation concentrate and the above-obtained dry roughing concentrate, coarse-grained titanium concentrate with a particle size of 40 - 160 mesh is obtained. The titanium grade of the coarse-grained titanium concentrate is 59.48%. The electrostatic separation middlings are collected and mixed with the dry magnetic scavenging concentrate of the next batch for continuous electrostatic separation.

[0080] After preparing the above-obtained fine-grained wet magnetic material into a pulp with a solid content of 20%, perform wet magnetic separation cleaning. The magnetic field intensity of the wet magnetic separation cleaning is 6500 GS to obtain wet magnetic separation cleaning concentrate and wet magnetic separation cleaning tailings.

[0081] Use a shaking table to perform gravity separation scavenging on the above-obtained wet magnetic separation cleaning tailings to obtain gravity separation scavenging concentrate. The stroke of the shaking table is 15 mm and the stroke frequency is 150 times / min; after mixing the wet magnetic separation cleaning concentrate and the gravity separation scavenging concentrate and drying, fine-grained titanium concentrate with a particle size of 100 - 400 mesh is obtained. The titanium grade of the fine-grained titanium concentrate is 59.06%.

[0082] In this example, the total titanium recovery rate of the coarse-grained titanium concentrate and the fine-grained titanium concentrate is 90.79%.

[0083] Example 2

[0084] The beneficiation method for fine-grained beach placer ore provided in this example includes the following steps:

[0085] The fine-grained beach placer ore is deslimed by a hydrocyclone, classified by a spiral classifier, concentrated and then prepared into a pulp with a solid content of 25%. Then, perform wet magnetic separation roughing on the pulp at a low magnetic field intensity. The magnetic field intensity is set to 5500 GS to obtain wet roughing concentrate and wet roughing tailings.

[0086] The wet roughing tailings are subjected to wet magnetic scavenging at a high magnetic field intensity, where the magnetic field intensity of the wet magnetic scavenging is set to 11,000 GS, to obtain wet magnetic scavenging concentrate.

[0087] The wet roughing concentrate and the wet magnetic scavenging concentrate obtained above are mixed and concentrated and dewatered, and then placed in a drying kiln for drying, where the drying temperature is 650 °C and the drying time is 10 min; then the dried mixed ore is subjected to cyclone classification to obtain coarse-grained wet magnetic material and fine-grained wet magnetic material. Among them, the particle size of the coarse-grained wet magnetic material is greater than 160 mesh (i.e., the particle size is greater than 96 microns); the particle size of the fine-grained wet magnetic material is less than 100 mesh (i.e., the particle size is less than 150 microns).

[0088] The above-prepared coarse-grained wet magnetic material is screened through a 60-mesh sieve, and the material passing through the sieve is subjected to dry magnetic roughing at a high magnetic field intensity, where the magnetic field intensity of the dry magnetic roughing is 8,500 GS, to obtain dry magnetic roughing concentrate and dry magnetic roughing tailings. The dry magnetic roughing tailings are subjected to dry magnetic scavenging at a high magnetic field intensity, where the magnetic field intensity of the dry magnetic scavenging is 9,500 GS, to obtain dry magnetic scavenging concentrate.

[0089] The above-obtained dry magnetic scavenging concentrate is heated at 130 °C and then subjected to electrostatic separation, where the electrostatic separation voltage is 21,000 V, to obtain electrostatic separation concentrate and electrostatic separation middlings. After the electrostatic separation concentrate and the above-obtained dry magnetic roughing concentrate are mixed, coarse-grained titanium concentrate with a particle size of 40 - 160 mesh is obtained, and the titanium grade of the coarse-grained titanium concentrate is 60.32%. The electrostatic separation middlings are recovered and mixed with the dry magnetic scavenging concentrate of the next batch, and electrostatic separation is continued.

[0090] After the above-obtained fine-grained wet magnetic material is formulated into a slurry with a solid content of 25%, wet magnetic cleaning is carried out, where the magnetic field intensity of the wet magnetic cleaning is 7,000 GS, to obtain wet magnetic cleaning concentrate and wet magnetic cleaning tailings.

[0091] The above-obtained wet magnetic cleaning tailings are subjected to gravity scavenging using a shaking table equipment to obtain gravity scavenging concentrate, where the stroke of the shaking table is 20 mm and the stroke frequency is 200 times / min; after the wet magnetic cleaning concentrate and the gravity scavenging concentrate are mixed and dried, fine-grained titanium concentrate with a particle size of 100 - 400 mesh is obtained, and the titanium grade of the fine-grained titanium concentrate is 60.08%.

[0092] In this embodiment, the total titanium recovery rate of the coarse-grained titanium concentrate and the fine-grained titanium concentrate is 88.41%.

[0093] Example 3

[0094] The beneficiation method for fine-grained beach placer provided in this embodiment includes the following steps:

[0095] The fine - grained beach placer is deslimed by a hydrocyclone, classified by a spiral classifier, and thickened, and then formulated into a pulp with a solid content of 30%. Subsequently, the pulp is subjected to rough wet magnetic separation at a low magnetic field intensity, where the magnetic field intensity is set to 6000 GS, to obtain rough wet magnetic separation concentrate and rough wet magnetic separation tailings.

[0096] The rough wet magnetic separation tailings are subjected to wet magnetic scavenging at a high magnetic field intensity, where the magnetic field intensity of the wet magnetic scavenging is set to 12000 GS, to obtain wet magnetic scavenging concentrate.

[0097] The rough wet magnetic separation concentrate and the wet magnetic scavenging concentrate obtained above are mixed and concentrated and dewatered, and then placed in a drying kiln for drying, where the drying temperature is 580 °C and the drying time is 20 min; then the dried mixed ore is subjected to cyclone classification to obtain coarse - grained wet magnetic material and fine - grained wet magnetic material. Among them, the particle size of the coarse - grained wet magnetic material is greater than 160 mesh (i.e., the particle size is greater than 96 microns); the particle size of the fine - grained wet magnetic material is less than 100 mesh (i.e., the particle size is less than 150 microns).

[0098] The above - prepared coarse - grained wet magnetic material is screened through a 40 - mesh sieve, and the undersize is subjected to rough dry magnetic separation at a high magnetic field intensity, where the magnetic field intensity of the rough dry magnetic separation is 9000 GS, to obtain rough dry magnetic separation concentrate and rough dry magnetic separation tailings. The rough dry magnetic separation tailings are subjected to dry magnetic scavenging at a high magnetic field intensity, where the magnetic field intensity of the dry magnetic scavenging is 9000 GS, to obtain dry magnetic scavenging concentrate.

[0099] The dry magnetic scavenging concentrate obtained above is heated at 120 °C and then subjected to electrostatic separation, and the electrostatic separation voltage is 20000 V, to obtain electrostatic separation concentrate and electrostatic separation middlings. After mixing the electrostatic separation concentrate and the rough dry magnetic separation concentrate obtained above, coarse - grained titanium concentrate with a particle size of 40 - 160 mesh is obtained, and the titanium grade of the coarse - grained titanium concentrate is 61.55%. The electrostatic separation middlings are recovered and mixed with the dry magnetic scavenging concentrate of the next batch, and continue to be subjected to electrostatic separation.

[0100] After the above - obtained fine - grained wet magnetic material is formulated into a pulp with a solid content of 30%, it is subjected to fine wet magnetic separation, where the magnetic field intensity of the fine wet magnetic separation is 8000 GS, to obtain fine wet magnetic separation concentrate and fine wet magnetic separation tailings.

[0101] The above - obtained fine wet magnetic separation tailings are subjected to gravity scavenging using a shaking table equipment to obtain gravity scavenging concentrate, where the stroke of the shaking table is 12 mm and the stroke frequency is 100 times / min; after mixing the fine wet magnetic separation concentrate and the gravity scavenging concentrate and drying, fine - grained titanium concentrate with a particle size of 100 - 400 mesh is obtained, and the titanium grade of the fine - grained titanium concentrate is 61.07%.

[0102] In this embodiment, the total titanium recovery rate of the coarse - grained titanium concentrate and the fine - grained titanium concentrate is 86.51%.

[0103] Comparative Example 1

[0104] The beneficiation method of the fine-grained beach placer provided in this comparative example is basically the same as that in Example 3, except that the fine-grained beach placer is directly subjected to cyclone classification without the steps of rough wet magnetic separation and wet magnetic scavenging.

[0105] In this comparative example, the total titanium recovery rate of the coarse-grained titanium concentrate and the fine-grained titanium concentrate is 80.62%.

[0106] By comparing Example 3 and Comparative Example 1, it can be seen that the present invention can improve the titanium recovery rate by first performing wet magnetic separation on the fine-grained beach placer.

[0107] Comparative Example 2

[0108] The beneficiation method of the fine-grained beach placer provided in this comparative example is basically the same as that in Example 3, except that cyclone classification is replaced by screening. Specifically, dry magnetic separation screening is carried out with 160 mesh to obtain coarse-grained wet magnetic material and fine-grained wet magnetic material. The particle size of the coarse-grained wet magnetic material is greater than or equal to 160 mesh, and the particle size of the fine-grained wet magnetic material is less than 160 mesh. However, the overall screening difficulty is large, the screen mesh is severely blocked, and it cannot adapt to large-scale industrial production.

[0109] By comparing Example 3 and Comparative Example 2, it can be seen that the cyclone classification method provided by the present invention reduces the classification difficulty and is more suitable for batch production.

[0110] Comparative Example 3

[0111] The beneficiation method of the fine-grained beach placer provided in this comparative example includes the following steps: screening the beach placer with a screening mesh number of 5 to obtain the screened material, de-sludging the screened material to obtain the sand deposit; performing dry weak magnetic separation on the sand deposit with a weak magnetic field intensity of 2000 GS to obtain weak magnetic separation concentrate and weak magnetic separation tailings, performing dry strong magnetic separation on the weak magnetic tailings with a magnetic separation magnetic field intensity of 8000 GS to obtain strong magnetic separation concentrate and strong magnetic separation tailings, performing electroseparation on the strong magnetic separation concentrate by flash drying under the condition of 20000 V to obtain electroseparation concentrate and electroseparation tailings. The final electroseparation concentrate is the titanium concentrate, with a grade of 53.91% and a titanium recovery rate of 79.17%.

[0112] Comparative Example 4

[0113] The beneficiation method of fine-grained beach placer provided in this comparative example includes the following steps: screening the beach placer with a screening mesh size of 5 meshes to obtain the screened material, desliming the screened material to obtain the sand concentrate; feeding the sand concentrate into a spiral chute for separation to obtain the gravity separation concentrate and the gravity separation tailings, conducting dry magnetic separation roughing on the gravity separation concentrate with a magnetic field intensity of 7000 GS to obtain the dry magnetic separation roughing concentrate and the dry magnetic separation roughing tailings, conducting dry magnetic separation scavenging on the dry magnetic separation roughing tailings with a magnetic field intensity of 7000 GS to obtain the dry magnetic separation scavenging concentrate and the dry magnetic separation scavenging tailings, and combining the dry magnetic separation roughing concentrate and the dry magnetic separation scavenging concentrate to obtain the titanium concentrate. The titanium grade of the titanium concentrate is 49.83% and the comprehensive titanium recovery rate is 63.19%.

[0114] By comparing each example and Comparative Examples 3-4, it can be seen that the beneficiation method of fine-grained beach placer provided by the present invention not only has a high titanium recovery rate, but also the obtained titanium concentrate has a high titanium grade.

[0115] Although the present invention has been illustrated and described with specific examples, it should be realized that the above examples are only used to illustrate the technical solutions of the present invention, rather than to limit it; those of ordinary skill in the art should understand that: without departing from the spirit and scope of the present invention, the technical solutions described in the foregoing examples can be modified, or some or all of the technical features can be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention; therefore, this means that all such replacements and modifications within the scope of the present invention are included in the appended claims.

Claims

1. A beneficiation method for fine-grained beach placer deposits, characterized in that, It includes the following steps: (a) After the pulp containing fine-grained beach placer is roughly selected by wet magnetic separation, a wet rough concentrate and a wet rough tailing are obtained; after the wet rough tailing is subjected to wet magnetic scavenging, a wet magnetic scavenging concentrate is obtained; Among them, the proportion of minerals with a particle size below 160 mesh in the fine-grained beach placer is 15% - 40%; (b) Mix and dry the wet rough concentrate and the wet magnetic scavenging concentrate, and then perform cyclone classification to obtain a coarse-grained wet magnetic material and a fine-grained wet magnetic material; (c) After screening the coarse-grained wet magnetic material, perform dry magnetic separation roughing to obtain a dry rough concentrate and a dry rough tailing; after the dry rough tailing is subjected to dry magnetic scavenging, a dry magnetic scavenging concentrate is obtained; (d) After the dry magnetic scavenging concentrate is subjected to electrostatic separation, an electrostatic separation concentrate is obtained; mix the electrostatic separation concentrate with the dry rough concentrate obtained in step (c) to obtain a coarse-grained titanium concentrate with a particle size of 40 - 160 mesh; (e) Prepare the fine-grained wet magnetic material obtained in step (b) into a pulp and perform wet magnetic beneficiation to obtain a wet magnetic beneficiation concentrate and a wet magnetic beneficiation tailing; perform gravity scavenging on the wet magnetic beneficiation tailing to obtain a gravity scavenging concentrate; mix and dry the wet magnetic beneficiation concentrate and the gravity scavenging concentrate to obtain a fine-grained titanium concentrate with a particle size of 100 - 400 mesh.

2. The beneficiation method of fine-grained beach placer according to claim 1, characterized in that, In step (a), the solid content of the pulp containing fine-grained beach placer is 20% - 30%.

3. The ore dressing method for fine-grained beach placer deposits according to claim 1, characterized in that, In step (a), the magnetic field intensity of the wet magnetic separation roughing is 4500 - 6000 GS.

4. The beneficiation method of fine-grained beach placer according to claim 1, characterized in that, In step (a), the magnetic separation intensity of the wet magnetic scavenging is 10000 - 12000 GS.

5. The beneficiation method of fine-grained beach placer according to claim 1, characterized in that, In step (b), the drying temperature is 550 - 700 °C, and the drying time is 10 - 60 min.

6. The beneficiation method of fine-grained beach placer as claimed in claim 1, wherein, In step (b), the particle size of the coarse-grained wet magnetic material is greater than 160 mesh, and the particle size of the fine-grained wet magnetic material is less than 100 mesh.

7. The beneficiation method of fine-grained beach placer as claimed in claim 1, wherein, In step (c), the screen aperture mesh number used for screening is 40 - 60 mesh.

8. The beneficiation method of fine-grained beach placer as claimed in claim 1, wherein, In step (c), the magnetic separation intensity of the dry magnetic separation roughing is 7500 - 9000 GS.

9. The beneficiation method of fine-grained beach placer according to claim 1, characterized in that In step (c), the magnetic field intensity of the dry magnetic scavenging is 8000 - 9500 GS.

10. The beneficiation method of fine-grained beach placer according to claim 1, characterized in that, In step (d), the voltage of the electrostatic separation is 18000 - 22000 V.

11. The beneficiation method of fine-grained beach placer according to claim 1, characterized in that, In step (e), the magnetic field intensity of the wet magnetic beneficiation is 6000 - 8000 GS.

12. The beneficiation method of fine-grained beach placer as claimed in claim 1, wherein In step (e), the gravity scavenging is carried out using a shaking table, and the stroke of the shaking table is 10 - 20 mm, and the stroke frequency is 100 - 250 times / min.

13. Application of the beneficiation method for fine-grained beach placer as described in any one of claims 1 - 12 in the production of titanium-rich materials and titanium tetrachloride.

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