Beneficiation method for recovering micro-fine particle grade phosphorus from iron separation tailings and application of beneficiation method

Abstract

The invention relates to a beneficiation method for recovering micro-fine particle grade phosphorus from iron beneficiation tailings and application of the beneficiation method, belongs to the technical field of comprehensive utilization of mineral resources, and solves the problems of serious loss of phosphorite and environmental pollution caused by low comprehensive recovery efficiency of phosphorus in low-grade phosphorite and tailings in the prior art. According to the beneficiation method, an iron beneficiation tailing overflow sample subjected to graded concentration treatment is adopted as raw ore, a hydrocyclone is adopted for grading the raw ore so as to remove part of micro-fine particle slime, and then flotation operation only including one-time roughing, one-time scavenging and one-time concentration is carried out. By means of the method, micro-fine-particle-grade phosphate minerals which are seriously lost due to grading concentration overflow of iron separation tailings at present can be effectively recycled, the grade of the recycled phosphate concentrate reaches 36% or above, the operation recovery rate is higher than 90%, and the process steps are simple and easy to implement; according to the beneficiation method, the recovery rate of phosphorus in the iron beneficiation tailings is effectively increased, and efficient development and comprehensive utilization of phosphorus resources in low-grade phosphorite and tailings are promoted.

Description

Technical Field

[0001] The invention relates to the technical field of comprehensive utilization of mineral resources, and in particular to a mineral processing method for recovering fine-grained phosphorus from iron ore tailings and its application. Background Art

[0002] Phosphate rock is a non-metallic mineral with strategic significance, which is mainly used to make phosphate fertilizer, yellow phosphorus, phosphoric acid and other phosphate salts, and is used in agriculture, medicine, food, national defense and other industries. Although my country has abundant phosphorus resources, they are unevenly distributed, mainly concentrated in the south, and less in the north, resulting in a serious phosphorus supply-demand deficit.

[0003] There are phosphate minerals in iron ore, especially in certain types of iron ore, such as hematite, magnetite, siderite, etc., with a high content; as a co-element of iron ore, phosphorus has an average grade of 2-3%. People often recycle phosphorus from iron ore tailings, which not only realizes resource recycling, but also reduces the pollution of tailings to the environment. At present, the coarse separation-inclined plate thickening desludging-flotation device is generally used. The flotation feed of this device is the inclined plate thickening bottom flow, which mainly recovers coarse and medium-sized phosphate minerals. Although the phosphorus in the iron ore tailings is recovered to a certain extent, the comprehensive recovery rate is low. The main reason is that the over-grinding or fine-grained embedded apatite is lost with the overflow of the inclined plate, and the fine-grained phosphate minerals cannot be effectively separated and recovered.

[0004] Therefore, there is an urgent need for a method to improve the efficiency of phosphorus recovery in iron ore tailings, which will be of great significance to strengthening the efficient development and utilization of phosphate resources, promoting the comprehensive utilization of medium and low-grade phosphate ores and tailings, and improving the sustainable guarantee capacity of my country's phosphorus resources. Summary of the invention

[0005] In view of the above analysis, the embodiments of the present invention aim to provide a mineral processing method and application for recovering fine-particle phosphorus from iron ore tailings, so as to solve at least one of the problems in the prior art of low comprehensive recovery efficiency of phosphorus in low-grade phosphate ore and tailings, resulting in serious loss of phosphate minerals and environmental pollution.

[0006] On the one hand, an embodiment of the present invention provides a method for recovering fine-grained phosphorus from iron ore tailings, the method comprising:

[0007] (1) subjecting the phosphorus-containing iron ore tailings to graded concentration treatment, feeding the graded concentration overflow into a hydrocyclone for ore slime removal, discharging the hydrocyclone overflow as tailings, and subjecting the hydrocyclone sand settling to phosphorus selection operations;

[0008] (2) slurrying the sediment obtained in step (1), adding an inhibitor and a collector, and mixing to obtain a slurry;

[0009] (3) feeding the slurry into a cyclone-static microbubble flotation column I for roughing to obtain a roughing concentrate and a roughing tailing;

[0010] (4) feeding the roughing concentrate into a cyclone-static microbubble flotation column II for concentrating to obtain phosphate concentrate and concentrating tailings, and returning the concentrating tailings to step (3) for roughing;

[0011] (5) The roughing tailings obtained in step (3) are fed into a cyclone-static microbubble flotation column III for scavenging, the scavenged concentrate is returned to step (3) for roughing, and the scavenged tailings are discharged as final tailings.

[0012] Furthermore, in step (1), the phosphorus grade of the overflow from the graded concentration is 2%-2.3%, the content of ore slime with a fineness of ≤30 μm is 80%-95%, and the content of ore slime with a fineness of ≤10 μm is 50%-65%.

[0013] Furthermore, in step (1), the inner diameter of the cyclone is 50-125 mm, the inner diameter of the sand settling port is 6-10 mm, the feed concentration is 8%-12%, and the feed pressure is 0.15-0.25 MPa.

[0014] Furthermore, the concentration of the sedimentation sand is 30%-35%, the content of the mineral mud with a fineness of ≤30 μm is 70%-80%, and the content of the mineral mud with a fineness of ≤10 μm is 20-40%.

[0015] Furthermore, in step (2), the collector comprises sodium oleate, oxidized paraffin soap and MES in a molar ratio of (2-5):(1-2):1, and the amount used is 500-700 g / t.

[0016] Furthermore, the inhibitor is water glass, and the dosage is 300-500g / t.

[0017] Furthermore, in step (3), the circulation pressure of the cyclone-static microbubble flotation column I is 0.15-0.25Mpa, the inflation volume is 1500-3500L / h, the foam layer thickness is 5-15cm, and the flotation time is 10-20min.

[0018] Furthermore, in step (4), the circulation pressure of the cyclone-static microbubble flotation column II is 0.15-0.25 MPa, the aeration volume is 1000-3000 L / h, the foam layer thickness is 5-15 cm, and the flotation time is 5-15 min.

[0019] Furthermore, in step (5), the circulation pressure of the cyclone-static microbubble flotation column III is 0.15-0.25 MPa, the aeration volume is 1000-3000 L / h, the foam layer thickness is 5-15 cm, and the flotation time is 5-15 min.

[0020] Furthermore, the concentration is carried out in the presence of the inhibitor, with a dosage of 100-250 g / t; the scavenging is carried out in the presence of the inhibitor and the collector, with dosages of 100-300 g / t and 200-500 g / t, respectively.

[0021] On the other hand, an embodiment of the present invention provides the use of the ore dressing method described in the first aspect to improve the recovery rate of phosphorus in iron ore tailings.

[0022] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0023] 1. The mineral processing method of the present invention adopts the overflow sample after classification and concentration treatment as the raw ore, adopts a cyclone to classify the raw ore to remove part of the fine-grained ore mud, and then only needs one roughing, one scavenging and one concentrating operation to effectively recover the fine-grained phosphate minerals that are currently seriously lost due to the overflow of the inclined plate. The grade of the recovered phosphate concentrate is more than 36%, the operation recovery rate is higher than 90%, and the process steps are simple and easy to implement.

[0024] 2. The present invention utilizes a cyclone to classify and desludge the iron ore tailings. By limiting the process parameters in the classifying and desludge process, the slime content and fineness in the pulp after the classifying and desludge treatment are controlled, creating conditions for the subsequent flotation recovery of fine-grained phosphate minerals. The present invention controls the concentration of the pulp entering the flotation operation within the range of 30%-35%, wherein the slime content of the pulp with a fineness of ≤30μm is 70%-80%, and the slime content of the pulp with a fineness of ≤10μm is 20%-40%.

[0025] 3. The present invention utilizes a cyclone-static microbubble flotation column to float minerals. The device combines cyclone and microbubble technology and is particularly suitable for the separation of fine-grained minerals. In the mineral flotation process of the present invention, by limiting the process parameters of each flotation step and combining the selection and dosage of the collector and / or inhibitor, efficient recovery of fine-grained phosphate minerals from the inclined plate overflow sample is achieved, achieving the purpose of effectively recovering fine-grained phosphorus from slurry with high sludge content and fineness, improving the comprehensive utilization rate of phosphorus in iron ore tailings, and reducing the pollution caused by tailings to the environment.

[0026] 4. The method of the present invention has few steps, is simple to operate and easy to implement; the equipment used has a simple structure, occupies a small area and has a large processing capacity; the amount of reagents used is small and the efficiency is high, which improves the comprehensive utilization rate of mineral resources, increases the added value of mineral products, and has significant social and economic benefits.

[0027] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings are only for the purpose of illustrating specific embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0029] Figure 1 The present invention is a schematic diagram of the process of recovering phosphorus from the overflow of graded concentration of iron ore tailings. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0031] At present, people generally use coarse separation-inclined plate thickening desludging-flotation device to recover phosphorus from iron ore tailings. The flotation feed of this device is inclined plate thickening bottom flow, which mainly recovers coarse and medium particle size (38-106μm) phosphate minerals. Although phosphorus in iron ore tailings is recovered to a certain extent, the overall recovery rate is low. The main reason is that over-grinding or fine-grained embedded apatite is lost with the overflow of graded concentration, and fine-grained phosphate minerals cannot be effectively separated and recovered.

[0032] Therefore, the present invention provides a method for recovering fine-grained phosphorus from iron ore tailings, which realizes efficient recovery of fine-grained phosphorus minerals in iron ore tailings. The process steps of the method are as follows: Figure 1 .

[0033] Specifically, the mineral processing method comprises the following steps:

[0034] (1) subjecting the phosphorus-containing iron ore tailings to graded concentration treatment, feeding the graded concentration overflow into a hydrocyclone for ore slime removal, discharging the hydrocyclone overflow as tailings, and subjecting the hydrocyclone sand settling to phosphorus selection operations;

[0035] (2) slurrying the sediment obtained in step (1), adding an inhibitor and a collector, and mixing to obtain a slurry;

[0036] (3) feeding the slurry into a cyclone-static microbubble flotation column I for roughing to obtain a roughing concentrate and a roughing tailing;

[0037] (4) feeding the roughing concentrate into a cyclone-static microbubble flotation column II for concentrating to obtain phosphate concentrate and concentrating tailings, and returning the concentrating tailings to step (3) for roughing;

[0038] (5) The roughing tailings obtained in step (3) are fed into a cyclone-static microbubble flotation column III for scavenging, the scavenged concentrate is returned to step (3) for roughing, and the scavenged tailings are discharged as final tailings.

[0039] It should be noted that the method for graded concentration of iron-separated tailings in the present invention can be gravity sedimentation, filtration, centrifugal separation, hydrocyclone, inclined plate thickening method, etc. Considering shortening the sedimentation distance and time of solid particles, improving sedimentation efficiency and processing volume, and reducing processing costs, the present invention preferably adopts inclined plate thickening method to grade and concentrate the iron-separated tailings to be treated.

[0040] Specifically, in step (1), the slurry concentration after the iron ore tailings are graded and concentrated by the present invention is 8%-12%. Furthermore, the phosphorus grade in the iron ore tailings after graded and concentrated is 2-2.3%, and the sludge size is fine particle size, with a fineness range of: 80%-95% for sludge ≤30μm and 50%-65% for sludge ≤10μm.

[0041] In the present invention, the iron tailings after graded concentration have a high sludge content and a high fineness. When directly subjected to flotation treatment, the sludge will cover the surface of the target mineral particles or adsorb a large amount of flotation drugs, making it difficult for the mineral particles to effectively contact with the bubbles, and increasing the slurry viscosity to affect the fluidity of the slurry and the rising speed of the flotation bubbles, thereby affecting the grade and recovery rate of the target phosphate minerals. Therefore, the present invention further performs graded desliming treatment on the slurry after graded concentration, and creates conditions for subsequent flotation recovery of fine-grained phosphate minerals by controlling the sludge content and fineness in the slurry.

[0042] Specifically, in step (1), after the ore pulp is graded and deslimed, the content of ore slime in the sediment is 30%-35%, the content of ore slime with a fineness of ≤30 μm is 70%-80%, and the content of ore slime with a fineness of ≤10 μm is 20-40%.

[0043] When the sludge fineness is too small or the concentration is too high, the sludge is easily entrained in the foam product, causing the concentrate grade to decrease; it will cover the surface of the mineral, affecting the interaction between the mineral and the reagent; and the high surface energy and specific surface area of ​​the sludge will adsorb a large amount of reagents, increase the consumption of reagents and thus increase the cost of mineral processing; and it will make the pulp sticky, affecting the interaction between the mineral and the bubble, thus affecting the flotation index. If the sludge concentration is too small, the subsequent processing volume will increase, the equipment load will be high, and the yield will be low. Generally, it needs to be concentrated to increase the concentration. If the concentration is too high, it can be reduced by adding water. If the sludge fineness is too large, it is not conducive to the subsequent flotation and recovery of fine-grained phosphate minerals using a cyclone-static microbubble flotation column.

[0044] It should be noted that the present invention can use spiral classifiers, hydrocyclones, hydraulic separators and other equipment to classify and deslim the ore pulp. Considering that the hydraulic desliming cyclone has a simple structure, a small footprint, is easy to install and operate, has a large production capacity per unit volume, a high classification efficiency (up to 80% to 90%), a fine classification particle size, and a low cost, the present invention preferably uses a hydraulic desliming cyclone to deslim the ore pulp to be floated.

[0045] Furthermore, the process parameters for removing slime from ore pulp using a cyclone in the present invention are as follows: the inner diameter of the cyclone is 50-125 mm, the inner diameter of the sand settling port is 6-10 mm, the feed concentration is 8%-12%, and the feed pressure is 0.15-0.25 MPa.

[0046] When the slurry is graded and desludged, the process parameters have an important influence on the control of the slime content and fineness in the slurry after graded and desludging. The inner diameter of the cyclone affects the production capacity and the separation particle size. As the diameter increases, the production capacity and the separation particle size also increase accordingly; as the inner diameter of the sand settling port increases, the sand settling amount increases, and the content of fine particles in the sand settling also increases, but when it is too large, the sand settling fineness is too fine, the sand settling port diameter is too small, the sand settling discharge volume is reduced, and it is easy to cause the "coarse running" phenomenon in the overflow, that is, the fine particles cannot be effectively separated and enter the overflow; too much feed concentration will increase the fluid viscosity resistance and reduce the classification efficiency; an increase in feed pressure will improve the classification efficiency and underflow concentration, but too large a diameter will increase energy consumption and increase the wear of the underflow nozzle.

[0047] In the present invention, a cyclone is used to classify and desludging the iron ore tailings. By limiting the process parameters in the classifying and desludging process, the sludge content and fineness in the slurry after the classifying and desludge treatment are controlled, creating conditions for the subsequent flotation recovery of fine-grained phosphate minerals. The sludge content of ore with a fineness of ≤30μm is 70%-80%, and the sludge content of ore with a fineness of ≤10μm is 20%-40%.

[0048] The present invention performs flotation operations on the ore pulp after desliming treatment, including roughing, scavenging and concentrating, and improves the recovery rate of phosphate minerals through roughing and scavenging, and improves the phosphorus grade through concentrating; the present invention can effectively recover fine-grained phosphate minerals, improve the comprehensive utilization rate of phosphorus in iron ore tailings, reduce the loss of over-grinding or fine-grained embedded apatite, and reduce the pollution of tailings to the environment through the setting of process steps and the limitation of relevant parameters.

[0049] In addition, the present invention utilizes a cyclone-static microbubble flotation column to float minerals. The device combines cyclone and microbubble technology and is particularly suitable for the separation of fine-grained minerals, simplifies process steps, and improves the recovery efficiency of fine-grained phosphate minerals. In addition, the flotation column has a simple structure, low energy consumption, small footprint, and easy operation and control.

[0050] Furthermore, in step (2), the present invention adds an inhibitor and a collector to the desludging treated sediment, stirs for 2-8 minutes at a stirring speed of 200-400 rpm, performs slurry adjustment, controls the concentration of the slurry to remain stable, and then performs roughing flotation operations to preliminarily obtain a concentrate with a high content of phosphate minerals.

[0051] Specifically, the inhibitor can be one or more of water glass, sodium hexametaphosphate, and sodium carboxymethyl cellulose. Considering the cost of the agent, the inhibitory performance of the agent, and the operability of the agent preparation and addition process, the present invention preferably uses water glass as the inhibitor of the flotation operation, which can effectively inhibit the gangue minerals in the slurry. The modulus of the water glass is 2-4, and the specific gravity is 1-2g / cm 3 , Baume degree is 25-40, and the dosage is 300-500g / t.

[0052] Specifically, the collector is a mixture of sodium oleate, oxidized paraffin soap and sodium methyl ester sulfonate (MES) in a molar ratio of (2-5):(1-2):1, has good selectivity, and the dosage is 500-700g / t.

[0053] Further, in step (3), the process parameters for roughing the pulp using a cyclone-static microbubble flotation column I are: a circulation pressure of 0.15-0.25Mpa, an aeration volume of 1500-3500L / h, a foam layer thickness of 5-15cm, and a flotation time of 10-20min. The circulation pressure affects the formation and stability of bubbles; the higher the aeration volume, the better the flotation effect, but too much aeration volume will cause the bubble size to be too large, which is not conducive to flotation; the thickness of the foam layer is appropriately controlled to improve the foam stability and flotation effect; the residence time of the pulp in the flotation column is controlled to improve the flotation efficiency.

[0054] The phosphorus grade in the phosphate concentrate obtained by rough selection of the present invention is 23.54-27.82%, and the recovery rate is 93.22-96.20%.

[0055] Furthermore, the present invention adds an inhibitor to the concentrate obtained by roughing, performs concentration to remove gangue and improve the grade of the phosphate mineral.

[0056] Specifically, in step (4), the amount of inhibitor added is 100-250 g / t.

[0057] Specifically, in step (4), the process parameters for concentrating the pulp using a cyclone-static microbubble flotation column II are: a circulation pressure of 0.15-0.25 MPa, an aeration volume of 1000-3000 L / h, a foam layer thickness of 5-15 cm, and a flotation time of 5-15 min.

[0058] The present invention returns the tailings obtained by concentration to the roughing operation for re-selection to improve the phosphorus recovery rate; and uses the phosphate concentrate obtained by concentration as the final flotation product.

[0059] Furthermore, the present invention adds inhibitors and collectors to the tailings obtained by roughing, and performs scavenging to further recover phosphorus minerals to improve the phosphorus recovery rate.

[0060] Specifically, in step (5), the amount of the inhibitor added is 100-300 g / t, and the amount of the collector added is 200-500 g / t.

[0061] Specifically, in step (5), the process parameters for scavenging the pulp using a cyclone-static microbubble flotation column III are: a circulation pressure of 0.15-0.25 MPa, an aeration volume of 1000-3000 L / h, a foam layer thickness of 5-15 cm, and a flotation time of 5-15 min.

[0062] The invention returns the concentrate obtained by scavenging to the roughing operation for re-selection to improve the phosphorus recovery rate; and discharges the tailings obtained by scavenging as the final tailings.

[0063] The above-mentioned mineral processing method of the present invention adopts the overflow sample after the inclined plate thickening treatment as the raw ore, adopts a cyclone to classify the raw ore to remove part of the fine-grained ore mud, and then only needs one roughing operation, one scavenging operation and one concentrating operation to effectively recover the fine-grained phosphate minerals that are currently seriously lost due to the overflow of the inclined plate. The grade of the recovered phosphate concentrate is more than 36%, the operation recovery rate is higher than 89%, and the process and equipment are simple and easy to implement.

[0064] The present invention also provides an embodiment of the present invention, which provides the use of the ore dressing method described in the first aspect for improving the recovery rate of phosphorus in iron ore tailings.

[0065] At present, the device for recovering phosphorus from iron ore tailings generally uses a coarse separator-inclined plate thickening desludging-flotation device, which mainly recovers coarse and medium-sized (38-106μm) phosphate minerals. Although the phosphorus in the iron ore tailings is recovered to a certain extent, the overall recovery rate is low. Over-grinded or fine-grained embedded apatite is lost with the overflow of the inclined plate, and the fine-grained phosphate minerals cannot be effectively separated and recovered.

[0066] Now, the ore dressing method of the present invention can efficiently recover fine-grained phosphate minerals, reduce the loss of over-grinding or fine-grained embedded apatite, improve the recovery rate of phosphorus in iron ore tailings, increase the added value of mineral products, and reduce the pollution caused by tailings to the environment, with significant benefits.

[0067] The reagents used in the flotation operation of the present invention are all commercially available products of chemically pure grade.

[0068] Example 1

[0069] (1) A phosphorus-containing iron ore tailings from Chengde, Hebei Province was subjected to primary inclined plate thickening treatment, and the inclined plate overflow sample was used as the raw ore and added to a hydraulic desludging cyclone for graded desludging; the raw ore concentration was 12%, the phosphorus grade was 2.02%, and the fineness range was: the ore slime content of ≤30μm was 92%, and the ore slime content of ≤10μm was 55%;

[0070] (2) In step (1), the inner diameter of the desludging cyclone is 75 mm, the inner diameter of the sand settling port is 8 mm, the feed concentration is 12%, and the feed pressure is 0.2 MPa. The obtained cyclone sand is used as the flotation raw material, wherein the concentration of the cyclone sand is 35%, the content of ore mud with a fineness of ≤30 μm is 77%, and the content of ore mud with a fineness of ≤10 μm is 35%; the overflow of the cyclone is discharged as tailings;

[0071] (3) adding 500 g / t of collector and 300 g / t of inhibitor to the cyclone sediment obtained in step (2), stirring at a speed of 400 rpm for 6 min to obtain a slurry to be floated, wherein the collector comprises sodium oleate, oxidized paraffin soap and MES in a molar ratio of 4:1:1, and the inhibitor is water glass;

[0072] (4) feeding the slurry to be floated obtained in step (3) into a cyclone-static microbubble flotation column I for roughing, wherein the process parameters are: a circulation pressure of 0.20 MPa, an aeration volume of 3000 L / h, a foam layer thickness of 15 cm, and a flotation time of 15 min, to obtain a roughing concentrate and a roughing tailing, wherein the phosphorus grade in the roughing concentrate is 24.66%, and the recovery rate is 95.48%;

[0073] (5) feeding the roughing concentrate obtained in step (4) into a cyclone-static microbubble flotation column II for concentrating, adding 150 g / t of water glass inhibitor, and the process parameters are: circulating pressure of 0.18 MPa, aeration volume of 2800 L / h, foam layer thickness of 10 cm, and flotation time of 12 min to obtain phosphate concentrate and concentrating tailings, and returning the concentrating tailings to step (3) for re-roughing, wherein the phosphorus grade in the phosphate concentrate is 37.18%, and the recovery rate is 92.65%;

[0074] (6) The roughing tailings obtained in step (3) are fed into a cyclone-static microbubble flotation column III for scavenging, and the amounts of collector and water glass inhibitor added are 300 g / t and 250 g / t, respectively. The collector comprises sodium oleate, oxidized paraffin soap and MES in a molar ratio of 5:1:1. The process parameters are: circulating pressure of 0.18 MPa, aeration volume of 2500 L / h, foam layer thickness of 10 cm, and flotation time of 10 min. The scavenged concentrate is returned to step (3) for re-roughing, and the scavenged tailings are discharged as final tailings.

[0075] Example 2

[0076] The same process steps as in Example 1 are used, except that:

[0077] In step (1), the original ore concentration is 10%, the phosphorus grade is 2.16%, and the fineness range is: the content of ore mud of ≤30μm is 85%, and the content of ore mud of ≤10μm is 53%; in step (2), the inner diameter of the desludging cyclone is 75mm, the inner diameter of the sand settling port is 6mm, the feed concentration is 12%, and the feed pressure is 0.20MPa. The obtained cyclone sediment is used as the flotation raw material, wherein the concentration of the cyclone sediment is 42%, the content of ore mud of fineness ≤30μm is 72%, and the content of ore mud of ≤10μm is 26%;

[0078] The phosphorus grade in the final phosphate concentrate is 37.24%, and the recovery rate is 91.26%.

[0079] Example 3

[0080] The same process steps as in Example 1 are used, except that:

[0081] In step (3), the dosage of collector and inhibitor is 500 g / t and 400 g / t respectively, and the collector comprises sodium oleate, oxidized paraffin soap and MES in a molar ratio of 4:1:1; the phosphorus grade in the final phosphate concentrate is 37.06%, and the recovery rate is 92.50%.

[0082] Example 4

[0083] The same process steps as in Example 1 are used, except that:

[0084] In step (4), the process parameters for roughing by using cyclone-static microbubble flotation column I are: circulation pressure of 0.18 MPa, aeration volume of 2800 L / h, foam layer thickness of 15 cm, flotation time of 15 min, and the phosphorus grade in the final phosphate concentrate is 36.48%, and the recovery rate is 91.29%.

[0085] Example 5

[0086] The same process steps as in Example 1 are used, except that:

[0087] In step (5), the process parameters for the cyclone-static microbubble flotation column II are: a circulation pressure of 0.20 MPa, an aeration volume of 3000 L / h, a foam layer thickness of 10 cm, a flotation time of 12 min, and the phosphorus grade in the final phosphate concentrate is 38.12%, and the recovery rate is 90.47%.

[0088] Comparative Example 1

[0089] The same process steps as in Example 1 are used, except that:

[0090] In step (1), the original ore concentration is 10%, the phosphorus grade is 2.23%, and the fineness range is: the content of ore slime of ≤30 μm is 98%, and the content of ore slime of ≤10 μm is 84%; the phosphorus grade in the final phosphate concentrate is 18.46%, and the recovery rate is 65.82%.

[0091] Comparative Example 2

[0092] The same process steps as in Example 1 are used, except that:

[0093] In step (2), the inner diameter of the desilting cyclone is 100 mm, the inner diameter of the sand settling port is 12 mm, the feed pressure is 0.18 MPa, and the obtained cyclone sand is used as the flotation raw material, wherein the concentration of the cyclone sand is 35%, the content of ore mud with a fineness of ≤30 μm is 85%, and the content of ore mud with a fineness of ≤10 μm is 53%;

[0094] The phosphorus grade in the final phosphate concentrate is 28.36%, and the recovery rate is 72.60%.

[0095] Comparative Example 3

[0096] The same process steps as in Example 1 are used, except that:

[0097] In step (3), the dosage of collector and inhibitor is 300 g / t and 200 g / t respectively, and the collector comprises sodium oleate, oxidized paraffin soap and MES in a molar ratio of 4:1:1; the phosphorus grade in the final phosphate concentrate is 30.95%, and the recovery rate is 85.86%.

[0098] Comparative Example 4

[0099] The same process steps as in Example 1 are used, except that:

[0100] In step (4), the process parameters for roughing by using cyclone-static microbubble flotation column I are: circulation pressure of 0.12 MPa, aeration volume of 1000 L / h, foam layer thickness of 5 cm, flotation time of 15 min, and the phosphorus grade in the final phosphate concentrate is 31.42%, and the recovery rate is 87.28%.

[0101] Comparative Example 5

[0102] The same process steps as in Example 1 are used, except that:

[0103] In step (5), the process parameters for the cyclone-static microbubble flotation column II are as follows: a circulation pressure of 0.15 MPa, an aeration volume of 800 L / h, a foam layer thickness of 5 cm, a flotation time of 8 min, and the phosphorus grade in the final phosphate concentrate is 32.69%, and the recovery rate is 86.30%.

[0104] Comparative Example 6

[0105] The same process steps as in Example 1 are used, except that:

[0106] The equipment used for flotation operation was a self-priming flotation agent, and the other process steps were the same as those in Example 1. The grade of the final phosphate concentrate was 27.34%, and the recovery rate was 80.25%.

[0107] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for recovering fine-grained phosphorus from iron ore tailings, characterized in that: The mineral processing method comprises: (1) subjecting the phosphorus-containing iron ore tailings to graded concentration treatment, feeding the graded concentration overflow into a hydrocyclone for ore slime removal, discharging the hydrocyclone overflow as tailings, and subjecting the hydrocyclone sand settling to phosphorus selection operations; (2) slurrying the sediment obtained in step (1), adding an inhibitor and a collector, and mixing to obtain a slurry; (3) feeding the slurry into a cyclone-static microbubble flotation column I for roughing to obtain a roughing concentrate and a roughing tailing; (4) feeding the roughing concentrate into a cyclone-static microbubble flotation column II for concentrating to obtain phosphate concentrate and concentrating tailings, and returning the concentrating tailings to step (3) for roughing; (5) The roughing tailings obtained in step (3) are fed into a cyclone-static microbubble flotation column III for scavenging, the scavenged concentrate is returned to step (3) for roughing, and the scavenged tailings are discharged as final tailings.

2. The ore dressing method according to claim 1, characterized in that: In step (1), the phosphorus grade of the overflow from the graded concentration is 2%-2.3%, the content of ore slime with a fineness of ≤30 μm is 80%-95%, and the content of ore slime with a fineness of ≤10 μm is 50%-65%.

3. The ore dressing method according to claim 1, characterized in that: In step (1), the inner diameter of the cyclone is 50-125 mm, the inner diameter of the sand settling port is 6-10 mm, the feed concentration is 8%-12%, and the feed pressure is 0.15-0.25 MPa.

4. The ore dressing method according to claim 1, characterized in that: The concentration of the sediment is 30%-35%, the content of the ore mud with a fineness of ≤30 μm is 70%-80%, and the content of the ore mud with a fineness of ≤10 μm is 20-40%.

5. The ore dressing method according to claim 1, characterized in that: In step (2), the collector comprises sodium oleate, oxidized paraffin soap and MES in a molar ratio of (2-5):(1-2):1, and the amount used is 500-700 g / t; The inhibitor is water glass, and the dosage is 300-500g / t.

6. The ore dressing method according to claim 1, characterized in that: In step (3), the circulation pressure of the cyclone-static microbubble flotation column I is 0.15-0.25Mpa, the inflation volume is 1500-3500L / h, the foam layer thickness is 5-15cm, and the flotation time is 10-20min.

7. The ore dressing method according to claim 1, characterized in that: In step (4), the circulation pressure of the cyclone-static microbubble flotation column II is 0.15-0.25Mpa, the aeration volume is 1000-3000L / h, the foam layer thickness is 5-15cm, and the flotation time is 5-15min.

8. The ore dressing method according to claim 1, characterized in that: In step (5), the circulation pressure of the cyclone-static microbubble flotation column III is 0.15-0.25Mpa, the aeration volume is 1000-3000L / h, the foam layer thickness is 5-15cm, and the flotation time is 5-15min.

9. The ore dressing method according to claim 1, characterized in that: The concentration is carried out in the presence of the inhibitor, with a dosage of 100-250 g / t; the scavenging is carried out in the presence of the inhibitor and the collector, with dosages of 100-300 g / t and 200-500 g / t respectively.

10. The ore dressing method according to any one of claims 1 to 9 is used to improve the recovery rate of phosphorus in iron ore tailings.

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