CN110860365A - The beneficiation method and device for improving quality and reducing impurities of low-grade fine-grained embedded magnetite - Google Patents

Abstract

The invention discloses a beneficiation method and device for improving quality and reducing impurities of low-grade micro-grain embedded magnetite, belonging to the technical field of beneficiation. In the method, low-grade micro-grain embedded magnetite is firstly subjected to high-pressure roller grinding and screening, and the screened product is subjected to coarse-grained wet pre-selection to obtain pre-selection concentrate and pre-selection tailings; the obtained pre-selection concentrate is subjected to The third-stage high-efficiency magnetic separation concentrate obtained by the three-stage grinding classification and the three-stage high-efficiency magnetic separation is the final iron concentrate. The device includes belt conveyor, intelligent blocking silo, hopper, high-pressure roller mill, high-efficiency fine powder screen, permanent magnetic wet coarse pre-separation magnetic separator, dewatering screen, hydrocyclone, high-efficiency permanent magnetic wet magnetic separator, Pump pool, slurry pump, tower mill, concentrate filter press, tailing pipe, total tailing pipe and ball mill. The invention has the characteristics of energy saving, green environmental protection, strong process adaptability and good stability, can significantly improve the grade of iron concentrate, and realize the efficient recovery of low-grade fine-grained magnetite.

Description

The beneficiation method and device for improving quality and reducing impurities of low-grade fine-grained embedded magnetite

Technical field:

The invention belongs to the technical field of beneficiation, and in particular relates to a beneficiation method and device for improving quality and reducing impurities of low-grade micro-grain embedded magnetite.

Background technique:

Iron ore is the most widely used and consumed metal ore in the world. It is the "grain" of the iron and steel industry and the "blood" of modern industrial development. my country's iron ore resources have more lean ore and less rich ore. Its main characteristics are "poor", "fine" and "miscellaneous", and the average iron grade is low. With the rapid development of my country's iron and steel industry, the demand for finished iron ore is increasing, the amount of iron ore that can be mined and used is gradually decreasing, the objects of beneficiation treatment are increasingly depleted, and the iron minerals in the ore gradually tend to be fine-grained- The characteristics of very fine particles embedded in the cloth make the beneficiation difficult, and the beneficiation cost is greatly increased.

In the field of iron ore beneficiation technology, the inlaid particle size of iron minerals is 0.045mm to 0.025mm, which belongs to the inlaid fine particles. At present, the beneficiation processes for processing fine-grained magnetite resources mainly include: stage grinding-single weak magnetic separation process, stage grinding-weak magnetic separation-reverse flotation process, stage grinding-weak magnetic separation (weak magnetic concentrate adopts panning Washing machine for quality improvement) process, stage grinding-weak magnetic separation-fine screen-weak magnetic separation process, stage grinding-weak magnetic separation-gravity separation process, etc. Among them, a company applied for "a beneficiation method for improving the stage grinding and sorting indicators of fine-grained magnetite" (CN107413517A), which is to add a fine screen to the magnetic separation coarse concentrate in the stage grinding-weak magnetic separation process. Screening, different types of weak magnetic separation are carried out on the sieve and under the sieve; a company applied for "an energy-saving mineral processing method for processing fine-grained magnetite" (CN107899738A), the patent is in the stage grinding - weak magnetic In the selection process, the elutriation process is added to the weak magnetic concentrate in the process to improve the final concentrate grade. However, in practical application, the above-mentioned process has the following problems: (1) all the raw ore finely divided products of magnetite need to be milled, the grinding volume is large, the energy consumption is high, and the beneficiation cost is high; (2) the use of stage grinding-single In the magnetic separation process, although the process is simple, the fine grinding stage has uneven particle size distribution, and minerals are prone to incomplete dissociation or over-grinding, which cannot effectively improve the concentrate grade; (3) Reverse flotation is used for concentrate extraction. Although a better mineral processing index can be obtained, the consumption of mineral processing chemicals will increase the production cost, and at the same time, the chemicals will have a certain impact on water resources. The water and electricity consumption is high, and the operating cost is high, and the medium ore generated by the washing machine will continue to return to the process. Therefore, according to the characteristics of low-grade and fine-grained embedded magnetite ore, research and development of economical, reasonable and technologically advanced beneficiation process and related supporting equipment with reliable work, high efficiency, energy saving, safety and environmental protection to improve the quality of concentrate and reduce the cost of beneficiation production has the advantages of important practical significance and exemplary role.

Invention content:

Aiming at the above deficiencies and defects mentioned in the prior art, the present invention provides a low-grade fine-grained embedded magnetite with good quality concentrate, low production cost, good process stability and adaptability, and a beneficiation method and device for improving quality and reducing impurities.

The concrete steps of the low-grade micro-grain embedded magnetite method for upgrading the quality and reducing impurities proposed by the present invention are as follows:

(1) After the low-grade micro-grain embedded magnetite is finely crushed and the particle size reaches 25-0 mm, the high-pressure roller mill is ultra-finely crushed to obtain a rolled product. The product and the product on the screen, the product on the screen is returned to the high-pressure roller mill to continue the ultra-fine crushing;

(2) carrying out coarse-grain wet pre-selection to the under-screen product obtained in step (1) to obtain pre-selection concentrate and pre-selection tailings;

(3) carrying out the first stage of grinding and classifying the preselected concentrate obtained in the step (2) to obtain overflow pulp and classified sand grit ore, and the classified grit grit ore is returned to carry out the first stage of grinding and classification;

(4) carrying out the first-stage high-efficiency magnetic separation of the overflow pulp obtained in the step (3) to obtain the first-stage high-efficiency magnetic separation concentrate and the first-stage high-efficiency magnetic separation tailings;

(5) carrying out the second-stage grinding and classification of the first-stage high-efficiency magnetic separation concentrate obtained in the step (4), to obtain overflow pulp and classifying grit ore, and returning the classified grit-precipitating ore to carry out the second-stage grinding and classification ;

(6) carrying out the second-stage high-efficiency magnetic separation of the overflow pulp obtained in step (5) to obtain the second-stage high-efficiency magnetic separation concentrate and the second-stage high-efficiency magnetic separation tailings;

(7) carrying out the third-stage grinding and classification of the second-stage high-efficiency magnetic separation concentrate obtained in the step (6) to obtain overflow pulp and classified sand-precipitating ore, and returning the classified sand-precipitating ore to the third-stage grinding grading;

(8) subjecting the overflow pulp obtained in step (7) to the third-stage high-efficiency magnetic separation to obtain the third-stage high-efficiency magnetic-separation concentrate and the third-stage high-efficiency magnetic-separation tailings, the third-stage high-efficiency magnetic separation concentrate That is the final iron concentrate.

The equipment used in the coarse-grain wet pre-selection in step (2) is a permanent magnet wet-type coarse-grain pre-selection magnetic separator, and the magnetic field intensity of the permanent-magnet wet-type coarse-grain pre-selection magnetic separator is 5000 Gs.

In step (2), the number of times of the high-efficiency magnetic separation in step (4), step (6) and step (8) is 1 time, and the magnetic field intensity of the high-efficiency magnetic separation is 4000Gs.

The first stage of grinding and classification refers to first ball milling and then hydrocyclone classification; the second stage of grinding and classification refers to the first stage of hydrocyclone classification and then tower grinding; the third stage of grinding The classification refers to the classification of the hydrocyclone first and then the tower grinding; the first stage of grinding and classification is carried out with a horizontal ball mill.

The pre-selected tailings obtained by the coarse-grained wet pre-selection in step (2) need to be classified, and the over-screen product obtained by the classification process is used as construction sand and gravel aggregate, and the under-screen product obtained by the classification process is highly efficient with the first stage. The magnetic separation tailings, the second-stage high-efficiency magnetic-separation tailings, and the third-stage high-efficiency magnetic separation tailings are combined into total tailings.

The particle size of the product under the high-efficiency fine powder sieve obtained in the step (1) is 3-0 mm.

In step (3), the obtained overflow pulp with a fineness of -200 mesh accounts for 65% to 75%.

In step (5), the obtained overflow pulp has a fineness of -325 mesh ≥ 70%.

In step (7), the obtained overflow pulp has a fineness of -500 mesh ≥ 95%.

In the method of the invention, the raw ore finely crushed products are first classified by the combined process of high-pressure roller mill-high-efficiency fine powder sieve-coarse-grain wet pre-selection to classify the high-pressure roller-pressed products, and the qualified products of the particle size are subjected to wet pre-selection, so as to ensure that in the coarse-grained state, Qualified tailings can be thrown out in advance, effectively enriching the concentrate, reducing the amount of grinding, so as to achieve the purpose of saving grinding, and the particle size of the rolled product is finer and its grindability is improved, which greatly improves the first. The processing capacity of stage grinding; in the subsequent stage grinding-stage magnetic separation process of the first stage high-efficiency magnetic separation concentrate, both stages of grinding are finely ground by tower mills, and the finely ground qualified products are selected. Do not use a high-efficiency magnetic separator, and the high-efficiency magnetic separation concentrate after the third-stage tower grinding is the final iron concentrate.

The high-pressure roller mill-high-efficiency fine powder screening-coarse-grain wet pre-selection process of the present invention is to realize more crushing and less grinding, throwing tails in advance, which can reduce the grinding amount of the first ball mill and improve the full iron grade of the grinding products. After pressing, the material is easy to grind, which greatly saves energy and reduces consumption, and reduces operating costs; tower mills are used for grinding in the second and third stages of grinding, which greatly improves the grinding efficiency of the fine grinding process, saves energy and reduces consumption, and the particle size of the grinding products is better. Uniform, effectively avoiding over-grinding.

The present invention also provides a beneficiation device for improving the quality and reducing impurities of low-grade micro-grain embedded magnetite. Warehouse 6.1, permanent magnet wet coarse pre-separation magnetic separator 7, dewatering screen 9, first hydrocyclone 11, first high-efficiency permanent magnet wet magnetic separator 14, first pump pool 17, second slurry pump 18, The second hydrocyclone 20 , the second high-efficiency permanent magnet wet magnetic separator 23 , the second pump pool 24 , the third hydrocyclone 27 , the third slurry pump 29 , the third high-efficiency permanent magnet wet magnetic separator 31 , the second tower mill 36 feeding the lower part, the concentrate filter press 33, the fourth row tail pipe 37, the third throwing tail pipe 38, the first tower mill 39 feeding the upper part, the second row tail pipe 40 , the first slurry pump 41 , the third pump pool 42 , the total tailings pipe 44 and the ball mill 45 .

The belt conveyor 1 is sequentially connected to the intelligent clearing silo 2, the hopper 3 and the high-pressure roller mill 4. The high-pressure roller mill 4 is connected to a high-efficiency fine powder screen 6 through a pipeline, and the high-efficiency fine powder screen 6. Connect the batching bin 6.1, the batching bin 6.1 is connected to the permanent magnet wet coarse pre-separation magnetic separator 7 through the sixteenth pipeline 6.2, and the permanent magnetic wet coarse pre-separation magnetic separator 7 is respectively connected to the dehydration screen 9 through the pipeline And the ball mill 45; the dewatering screen 9 is connected to the total tailings pipe 44 through the pipeline, the ball mill 45 is connected to the third pump pool 42 through the fifteenth pipeline 43, and the third pump pool 42 is connected to the first slurry pump 41 and the second pipeline 42. 12 is connected to the first hydrocyclone 11, the first hydrocyclone 11 is connected to the ball mill 45 through the first pipeline 10; the first hydrocyclone 11 is connected to the first high-efficiency permanent magnet wet magnetic separator through the third pipeline 13 14. The first high-efficiency permanent magnet wet magnetic separator 14 is connected to the total tailings pipe 44 through the second throwing tail pipe 40, and the first high-efficiency permanent magnet wet magnetic separator 14 is connected to the first pump pool 17 through the fifth pipeline 16. A pump pool 17 is connected to the second hydrocyclone 20 through the second slurry pump 18 and the sixth pipeline 19 , and the second hydrocyclone 20 is connected to the first tower mill 39 feeding the upper feed through the seventh pipeline 21 . , the first tower mill 39 feeding the upper part is connected to the first pump tank 17 through the fourth pipeline 15, the second hydrocyclone 20 is connected to the second high-efficiency permanent magnet wet magnetic separator 23 through the eighth pipeline 22, and the first The second high-efficiency permanent magnet wet magnetic separator 23 is connected to the total tailings pipe 44 through the third tailing pipe 38 , the second high-efficiency permanent magnet wet magnetic separator 23 is connected to the second pump pool 24 through the ninth pipeline 25 , and the second pump pool 24 is connected to the third hydrocyclone 27 through the tenth pipeline 26 through the third slurry pump 29, and the third hydrocyclone 27 is connected to the second tower mill 36 feeding the lower part through the twelfth pipeline 30. The second tower mill 36 for feeding is connected to the second pump pool 24 through the fourteenth pipeline 35, the third hydrocyclone 27 is connected to the third high-efficiency permanent magnet wet magnetic separator 31 through the eleventh pipeline 28, and the third The high-efficiency permanent magnet wet magnetic separator 31 is connected to the general tailings pipe 44 through the fourth throwing tail pipe 37 , and the third high-efficiency permanent magnet wet magnetic separator 31 is connected to the concentrate filter press 33 through the thirteen pipelines 32 .

The invention provides a method and a device for improving quality and reducing impurities for processing low-grade fine-grain embedded magnetite. Stage tower mill-high-efficiency magnetic separation-three-stage tower mill-high-efficiency magnetic separation is a new grinding process, which has the characteristics of energy saving, consumption reduction, emission reduction, green environmental protection, strong process adaptability and good stability, which can significantly improve the iron concentration ore grade, realizing the efficient recovery of low-grade fine-grained magnetite.

The high-pressure roller mill-high-efficiency fine-powder screening-coarse-grain wet pre-selection process of the present invention aims to discard qualified tailings as soon as possible, and select 3-0mm coarse-grained pre-selection concentrates to reduce the amount of ore into the first stage of ball milling, It also improves the total iron grade of the milled product, and the particle size of the rolled product becomes finer and its grindability is improved, which also greatly improves the processing capacity of the first-stage grinding; the two-stage grinding after the first-stage high-efficiency magnetic separation adopts the tower. Grinding by the mill can greatly improve the grinding efficiency of the fine grinding process, save energy and reduce consumption, and the particle size of the grinding products is more uniform, which is conducive to sorting. Magnetic separation can not only effectively improve the grade of magnetite concentrate, but also ensure the recovery rate of iron.

In the roughing process, the raw ore with a size of 25-0mm after being finely crushed is transported by the belt conveyor 1 to the intelligent clearing silo 2 for storage, and the material is fed into the high-pressure roller mill 4 through the hopper 3 for ultra-fine crushing, and the rolled material enters the The high-efficiency fine powder sieve 6 is sieved, and the material on the sieve is returned to the hopper 3 through the high-angle belt conveyor 5, and then rolled, and the material under the sieve is fed into the batching bin 6.1. After batching, it passes through the sixteenth pipeline 6.2. Enter the permanent magnet wet coarse pre-separation magnetic separator 7 for coarse pre-selection, and the rougher tailings enter the dewatering screen 9 for dehydration and classification. The material 9.1 on the screen is a good building material, and the material 9.2 under the screen is thrown into the total tail. Mine pipe 44. The coarse-grained concentrate enters the ball mill 45 through the pipeline 8, and enters the high-efficiency fine grinding process.

In the roughing process, the intelligent clearing silo 2 has various forms, and can choose a cylindrical flat-bottom silo (ZL2014 10243926·3), a rectangular conical silo (ZL2014 1 0245732 7), a V-shaped silo (ZL2014 1 0245063· 3) and other forms and specifications of clearing silos.

The high-pressure roller mill in the present invention adopts the hinged frame structure to facilitate the disassembly and assembly of the roller system, the hard alloy studs on the roller surface, the self-generated wear-resistant protective layer, and its service life can reach 6,000-20,000 hours, and the unique side baffle wear-resistant protection The technology does not require frequent replacement of roller sleeves, and can achieve rapid roll back and self-guided deviation. This machine can achieve ultra-fine crushing, more crushing and less grinding, more uniform product particle size distribution, higher fine-grained content, convenient mineral pre-selection, reduced grinding amount, and a large number of cracks in the grinding minerals, easy to fine grinding, can be greatly reduced. Reduce ball mill energy consumption. The range of technical parameters to choose from: roller diameter: Φ1000mm～2000mm, roller surface length: 250～1800mm, supporting motor: 220kw～4200kw, feeding particle size: 20mm～60mm, throughput: 80～1900t/h; the details can be seen Chinese patent ZL201120126820.1.

The high-efficiency fine powder sieve in the present invention is a high-efficiency dry screening equipment, and the screening efficiency of the ordinary circular vibrating screen is improved by more than 15%. The material on the sieve obtains a bouncing acceleration of 30-50g, which enhances the activity of the material, is not easy to stick to the sieve and block holes, and is fully loosened and penetrated through the sieve. The main technical performance range for selection: circular amplitude 4~7.5mm, linear amplitude 12~18mm, material acceleration 30~50g, feeding particle size 0~80mm, grading particle size 2~8mm, screen surface size and width range: 1500~ 3000mm, the length range is 5250~10000mm, the screening area is 7.88~30m2, the processing capacity range is 80~500t/h, and the motor power range is 11~37kw. For details, see Chinese patent CN20181 0605198A.

The permanent magnet wet coarse-grain pre-separation magnetic separator in the present invention is a pre-selection device for ferromagnetic materials before being milled. The downstream tank structure ensures the fluidity of coarse-grained materials, the coarse-grained outlet is adjustable, and the magnetic system is specially designed to ensure full recovery of useful minerals, effectively remove qualified tailings, and improve the grinding grade and production efficiency of the ball mill. , to achieve the purpose of energy saving and consumption reduction. The surface of the magnetic cylinder and the flow surface of the tank body adopt wear-resistant measures to improve the service life. The specially designed tank body ensures smooth and smooth flow of the slurry without clogging. Its optional technical parameters range : The diameter of the cylinder is 900～1500mm, the length of the cylinder is 1800～4500mm, the rotation speed is 25～13.6r/min, and the magnetic induction intensity of the cylinder surface is determined according to the properties of the ore. Processing capacity range: dry ore volume 40～240t/h, pulp volume 110～600m3/h, motor power 4～22kw. For details, see Chinese patent ZL201510241349.9.

In the rough separation process of the present invention, the high-pressure roller mill is used for ultra-fine crushing, the high-efficiency fine powder sieve is used for classification, and the permanent magnet wet coarse-grain pre-separator is used for coarse-grain pre-selection; when the coarse-grained concentrate enters the ball mill 45 from the pipeline 8 , into the high-efficiency fine grinding and high-efficiency selection process.

The ball-milled material enters the third pump pool 42 through the fifteenth pipeline 43, enters the first hydrocyclone 11 through the first slurry pump 41, and the second pipeline 12, and passes through the first hydrocyclone. The coarse-grain bottom flow processed by the device 11 is returned to the ball mill 45 through the second pipeline 10 for secondary ball milling, and the overflow processed by the first hydrocyclone 11 enters the first high-efficiency permanent magnet through the third pipeline 13. The first stage of high-efficiency magnetic separation is carried out in the wet magnetic separator 14, the bottom of which is thrown into the main tailings pipe 44 through the second tailing pipe 40, and the concentrate enters the first pump pool 17 through the fifth pipeline 16, Through the second slurry pump 18 and the sixth pipeline 19, it enters the second hydrocyclone 20 for classification, wherein the bottom flow of the second hydrocyclone 20 enters the first tower of the upper feed through the seventh pipeline 21 The ultra-fine grinding is carried out in the mill 39, and the ground material is returned to the first pump pool 17 through the fourth pipeline 15, and enters the internal small circulation, and the overflow of the second hydrocyclone 20 passes through the eighth pipeline 22. Enter into the second high-efficiency permanent magnet wet magnetic separator 23 for the second-stage high-efficiency magnetic separation, the bottom flow is discharged into the total tailings pipe 44 through the third throwing tail pipe 38, and the concentrate is discharged through the ninth pipeline 25. In the second pump pool 24, it enters the third hydrocyclone 27 through the third slurry pump 29 and the tenth pipeline 26 for classification, and the bottom flow enters the second feeder of the lower feed through the twelfth pipeline 30. The second stage of fine grinding is carried out in the second tower mill 36, the lower feed is selected to prevent the material from being over-ground, and the overflow product of the second tower mill 36 is returned to the second pump pool 24 through the fourteenth pipeline 35 to form Internal circulation of the second tower mill 36 . The overflow product of the third hydrocyclone 27 enters the third stage of high-efficiency magnetic separation through the eleventh pipeline 28 for final beneficiation, and the bottom flow is discharged into the general tailings pipe 44 through the fourth tailing pipe 37 . Finally, the iron concentrate enters the concentrate filter press 33 through the thirteenth pipeline 32, and the iron concentrate 34 is obtained after dehydration.

The high-efficiency permanent magnet wet magnetic separator in the present invention is made of high-performance materials, and the magnetic system design breaks through the magnetic circuit distribution structure of the magnetic system of the traditional magnetic separator to form a magnetic field with gradual, smooth, and high magnetic stirring factor performance and match it. The multi-functional tank body breaks through the traditional concept of magnetic separation, obtains high grade and high recovery rate, and is supported by the National Ministry of Science and Technology's innovative technology fund. This machine is most suitable for mineral sorting after fine grinding by tower mill. The optional range of its main technical performance parameters is as follows: the diameter of the cylinder is Φ750-1500mm, the length of the cylinder is 1500-6000mm, the rotation speed is 35-13.6r/min, and the magnetic induction intensity of the cylinder surface is determined according to the properties of the ore. Processing capacity range: dry ore volume 25～300t/h, pulp volume 80～750m3/h, motor power 2.2～30kw. For details, see Chinese Patent ZL20082 0037987.4.

The tower mill in the present invention adopts a closed-circuit grinding circuit, and the material is fed by the underflow of the hydrocyclone. During the grinding process, the coarse particles sink and the fine particles float up, and the flow process is naturally stratified, and the grinding strength of the lower part of the mixing drum is strong. The maximum grinding strength gradually weakens from the bottom to the top, which is coupled with the natural stratification. The large particles are in the area of high grinding strength and the fine particles are in the area of weaker strength. This process is the basic principle of high efficiency and energy saving of tower mills. where. The floating fine particles flow from the upper overflow port of the tower mill to the pump pool, and are transported to the hydrocyclone by the slurry pump to form the closed-circuit grinding of the tower mill. The optional range of the main technical parameters of the tower mill: pulp processing capacity 120-4800t/d, medium weight 7.2-120t, screw diameter 810-3300mm, screw revolution 19-65r/min, mixing drum diameter 1200-4200mm, mixing drum height 3000～4775mm, mixing drum volume 3.5～66m3, motor power 75kw～1200kw; see Chinese patent ZL201510241325.3 for details. The basic structure of the tower mill in the present invention is shown in Figures 3-5. The tower mill has energy-saving and high-efficiency grinding, high energy utilization rate, low consumption of grinding media, small footprint, low installation cost, and can be installed in the open air. The equipment operation rate is as high as 98%, and the maintenance workload is small. The product fineness is easy to adjust, the particle size distribution is uniform, the feeding position is flexible, the noise is lower than 85dB, the operation is simple, safe, and easy to intelligently control.

Compared with the prior art, the present invention has the following technical characteristics:

(1) The present invention adopts the high-pressure roller milling of finely crushed products-high-efficiency fine-powder screening-coarse-grained wet pre-selection technology to carry out ultra-fine crushing of the raw ore, so as to realize more crushing and less grinding. The high-efficiency fine powder sieve sieves the high-pressure roller mill products, and the qualified grades are subjected to coarse-grain wet pre-selection, which can realize wet tailing under the condition of coarse-grained. Compared with the existing beneficiation process, the mineral processing technology of the present invention reduces the energy consumption by more than 20%, and the coarse-grained products screened from the coarse-grained tailings have a correspondingly lower iron-containing grade. Qualified tailings can also be used as sand and gravel aggregate products, forming a new economic growth point.

(2) The two-stage tower grinding-magnetic separation process adopted by the present invention for the obtained one-stage high-efficiency magnetic separation concentrate can improve the grinding efficiency, reduce overgrinding, and save energy consumption, and the high-efficiency fine-grained magnetic separator is compatible with existing Compared with the magnetic separator, the grade of iron concentrate can be improved by more than 2%.

(3) The process of the present invention is green and environmentally friendly, and does not need to use flotation reagents.

(4) The present invention is aimed at low-grade micro-grain embedded magnetite, adopts a specific beneficiation method to cast tails in advance, finely grind and select, improve quality and reduce impurities, and has better economic and environmental protection value; and adopts flotation method to extract High quality, high cost, and environmental pollution. The conventional stage grinding-single magnetic separation process requires all the grinding, the grinding cost is high, and the technological and economic added value of the process is low.

Description of drawings:

Fig. 1 is the structure schematic diagram of the beneficiation device for improving the quality and reducing impurities of low-grade micro-grain embedded magnetite of the present invention;

Fig. 2 is the structure schematic diagram of the tower mill in the beneficiation device of the present invention;

Fig. 3 is the working cycle schematic diagram of tower mill and hydrocyclone in the beneficiation device of the present invention;

Fig. 4 is the transmission schematic diagram of the tower mill in the beneficiation device of the present invention;

FIG. 5 is a schematic diagram of the installation of the stirring screw of the tower mill in the beneficiation device of the present invention.

In the picture: 1: belt conveyor; 2: intelligent clearing silo; 3: hopper 3; 4: high pressure roller mill; 5: belt with high lift angle; 6: high-efficiency fine powder sieve; 6.1: batching bin; 6.2: tenth Six pipelines; 7: Permanent magnet wet coarse pre-separation magnetic separator; 8: pipeline; 9: dewatering screen; 10: first pipeline; 11: first hydrocyclone; 12: second pipeline; 13 : the third pipeline; 14: the first high-efficiency permanent magnet wet magnetic separator; 15: the fourth pipeline; 16: the fifth pipeline; 17: the first pump pool; 18: the second slurry pump; 19: the first Six pipelines; 20: The second hydrocyclone; 21: The seventh pipeline; 22: The eighth pipeline; 23: The second high-efficiency permanent magnet wet magnetic separator; 24: The second pump pool; 25: The ninth Pipeline; 26: The tenth pipeline; 27: The third hydrocyclone; 28: The eleventh pipeline; 29: The third slurry pump; 30: The twelfth pipeline; 31: The third high-efficiency permanent magnet wet type Magnetic separator; 32: Thirteen pipelines; 33: Concentrate filter press; 34: Iron concentrate; 35: Fourteenth pipeline; 36: Second tower mill for lower feeding; 37: Fourth throwing Tail pipe; 38: The third throwing tail pipe; 39: The first tower mill for the upper feeding; 39.1: The transmission system of the tower mill; 39.2: The reducer cover seat; 39.3: The drive unit base; ;39.5: Upper part of mixing drum; 39.6: Lower part of mixing drum; 39.7: Access door; 39.8: Door frame; Tail fixing block; 39.14: trolley track; 39.1.1: main motor; 39.1.2: split serpentine coupling; 39.1.3: reducer; 39.1.5: thrust bearing box; 39.1.6: pair Open sliding bearing seat; 39.1.7: drive shaft; 39.1.8: connecting flange; 39.1.9: stirring screw assembly; 40: second throwing tail pipe; 41: first slurry pump; 42: third Pump pool; 43: fifteenth pipeline; 44: total tailings pipe; 45: ball mill.

Detailed ways:

In order to facilitate understanding of the present invention, the present invention will be described more comprehensively and in detail with reference to the accompanying drawings and preferred embodiments, but the protection scope of the present invention is not limited to the following specific embodiments.

The typical fine-grained inlaid magnetite ore treated in this example has fine crystal grain size and complex structure. The main iron minerals are magnetite, followed by red (limonite) iron ore, iron carbonate and iron silicate, gangue minerals are mainly siliceous oxides and iron silicate minerals, with a small amount of carbonate and calcium magnesium silicon acid minerals. The statistical results of the measurement of the inlaid particle size of the magnetite under the electron microscope show that the particle size of the magnetite (including maghemite) is relatively fine, about 54.38% is distributed in -0.038mm, and the content of -0.074mm is 76.41%. The limonite inlaid grain size is relatively coarse.

The present invention is used in a technical transformation project of a magnetite concentrator in Shanxi, with "high pressure roller mill + coarse particle pre-selection", "tower mill + high-efficiency magnetic separation" as the core technology, GLGY type high pressure roller mill, T-CCT Type coarse grain pre-separator, TGTM type tower mill and T-GCT series high-efficiency concentrator and other energy-saving and high-efficiency patented equipment constitute the mineral processing device of the present invention, forming a "high-pressure roller mill + coarse-grain pre-selection-ball mill-tower mill + high-efficiency magnetic separation" "The beneficiation process has achieved great success in the industrial application of the beneficiation production of low-grade fine-grained embedded magnetite ore. The specific process steps are as follows:

(1) The 25-0mm raw ore with an iron grade of 24.26% is subjected to ultra-fine crushing by a high-pressure roller mill, and the rolled product is subjected to closed-circuit screening through a 3mm high-efficiency fine powder screen. , the material under the sieve is subjected to wet coarse pre-selection.

(2) carry out coarse-grain wet pre-selection to the under-screened product in step (1), the number of pre-selection stages is one stage, and the magnetic field intensity is 5000 Gs to obtain pre-selection tailings and the yield rate is 76.76%, the iron grade is 28.32%, and the iron recovery rate is 89.61% % pre-selected coarse concentrate; pre-selected tailings are screened by 0.5mm dewatering screen to produce construction sand and gravel aggregate with a yield rate of 10.05%, iron grade less than or equal to 9.52%, and particle size of 0.5-3mm.

(3) Pre-selecting the coarse-grained concentrate, using a horizontal ball mill for the first stage grinding, and then classifying the ground product with a hydrocyclone to obtain overflow pulp and underflow sand settling, and fine-grained overflow pulp The degree of -200 mesh accounts for 70%, and the bottom flow of the hydrocyclone is returned to the horizontal ball mill for grinding and classification;

(4) The overflow slurry in step (3) is subjected to the first-stage high-efficiency magnetic separation, the number of magnetic separations is 1, and the magnetic field intensity is 4000Gs, to obtain the first-stage high-efficiency magnetic separation tailings and the yield rate is 42.46%, iron The first-stage high-efficiency magnetic separation concentrate with a grade of 41.52% and an iron recovery rate of 72.33%;

(5) The first stage of high-efficiency magnetic separation concentrate in step (4) is subjected to hydrocyclone classification to obtain overflow slurry and underflow sand settling. The fineness of overflow ore pulp is -325 mesh, accounting for 70%, and underflow sand settling returns to To the tower mill for fine grinding, the finely ground products enter the hydrocyclone for classification.

(6) The overflow slurry in step (5) is subjected to the second-stage high-efficiency magnetic separation, the number of magnetic separations is 1, and the magnetic field intensity is 4000Gs, to obtain the second-stage high-efficiency magnetic separation tailings and the yield rate is 26.92%, iron The second-stage high-efficiency magnetic separation concentrate with a grade of 56.31% and an iron recovery rate of 62.48%.

(7) The second stage of high-efficiency magnetic separation concentrate in step (6) is subjected to hydrocyclone classification to obtain overflow slurry and underflow sand settling. The fineness of the overflow ore slurry is -500 mesh, accounting for 95%, and the underflow sand settling returns to The tower mill performs fine grinding, and the finely ground products enter the hydrocyclone for classification.

(8) The overflow pulp in step (7) is subjected to the third-stage high-efficiency magnetic separation, the number of magnetic separations is 1, and the magnetic field intensity is 4000Gs, so as to obtain the third-stage high-efficiency magnetic separation tailings and the yield rate is 21.94%. Iron concentrate with a grade of 65.13% and an iron recovery rate of 58.89%; three high-efficiency magnetic separation tailings obtained in steps (4), (6) and (8) are combined into the final total tailings.

The raw ore grade of the present invention is about 24.26%, and the technical indicators of the total iron grade of the iron ore concentrate of 65.13% and the recovery rate of 58.89% are obtained by using the present invention, which are respectively increased by 3.13 percentage points and 4 percentage points compared with the original production indicators.

In the process of processing low-grade fine-grained embedded magnetite ore, the high-pressure roller mill product adopts 3mm closed circuit, and the -3mm roller-pressed product adopts coarse-grained wet pre-selection, which can discard about 23% of coarse-grained tailings and coarse-grained tailings. The coarse-grained products screened out have relatively low iron content. They are not only qualified tailings, but also can be used as sand and gravel aggregate products, forming a new economic growth point. The fine-grained products under the sieve enter the total tailings. . The coarse-grained pre-selected coarse concentrate of 3-0mm not only reduces the grinding amount of the first ball mill, but also improves the total iron grade of the grinding product, and the particle size of the rolled product becomes finer and its grindability is improved, which is also greatly improved. The processing capacity of a period of grinding. The invention replaces the original two-stage and three-stage long-tube ball mill fine grinding process, completely solves the requirement of -500 mesh and 95% for iron ore, and the tower mill has higher grinding efficiency than the ball mill, and is more efficient. Energy saving, the particle size of the grinding products is more uniform, which is more conducive to the separation; on the other hand, the high-efficiency magnetic separator is used for magnetic separation, and on the basis of ensuring the recovery rate, the concentrate grade also reaches more than 65%.

Claims (6)

1. the beneficiation method for improving the quality and reducing impurities of low-grade micro-grain embedded magnetite, it is characterized in that the concrete steps of this beneficiation method are as follows: (1) After the low-grade micro-grain embedded magnetite is finely crushed and the particle size reaches 25-0 mm, the high-pressure roller mill is ultra-finely crushed to obtain a rolled product. The product and the product on the screen, the product on the screen is returned to the high-pressure roller mill to continue the ultra-fine crushing; (2) carrying out coarse-grain wet pre-selection to the under-screen product obtained in step (1) to obtain pre-selection concentrate and pre-selection tailings; (3) carrying out the first stage of grinding and classifying the preselected concentrate obtained in the step (2) to obtain overflow pulp and classified sand grit ore, and the classified grit grit ore is returned to carry out the first stage of grinding and classification; (4) carrying out the first-stage high-efficiency magnetic separation of the overflow pulp obtained in the step (3) to obtain the first-stage high-efficiency magnetic separation concentrate and the first-stage high-efficiency magnetic separation tailings; (5) carrying out the second-stage grinding and classification of the first-stage high-efficiency magnetic separation concentrate obtained in the step (4), to obtain overflow pulp and classifying grit ore, and returning the classified grit-precipitating ore to carry out the second-stage grinding and classification ; (6) carrying out the second-stage high-efficiency magnetic separation of the overflow pulp obtained in step (5) to obtain the second-stage high-efficiency magnetic separation concentrate and the second-stage high-efficiency magnetic separation tailings; (7) carrying out the third-stage grinding and classification of the second-stage high-efficiency magnetic separation concentrate obtained in the step (6) to obtain overflow pulp and classified sand-precipitating ore, and returning the classified sand-precipitating ore to the third-stage grinding grading; (8) subjecting the overflow pulp obtained in step (7) to the third-stage high-efficiency magnetic separation to obtain the third-stage high-efficiency magnetic-separation concentrate and the third-stage high-efficiency magnetic-separation tailings, the third-stage high-efficiency magnetic separation concentrate That is the final iron concentrate. 2. according to the described low-grade micro-grain embedded magnetite ore beneficiation method for improving quality and reducing impurities according to claim 1, it is characterized in that the equipment that the coarse-grained wet pre-selection described in the step (2) adopts is the permanent magnet wet-type coarse-grained pre-selection magnetic The magnetic field strength of the permanent magnet wet coarse-grain pre-selection magnetic separator is 5000Gs. 3. according to the described low-grade fine-grain embedded magnetite ore beneficiation method for improving quality and reducing impurities according to claim 1, it is characterized in that described in step (2) in step (4), step (6) and step (8) with high efficiency The number of magnetic separations is 1, and the magnetic field strength of the high-efficiency magnetic separation is 4000 Gs. 4. according to the described low-grade micro-grain embedded magnetite ore beneficiation method for improving quality and reducing impurities according to claim 1, it is characterized in that described first-stage grinding and grading refers to carrying out ball milling first and then carrying out hydrocyclone classification; the described The second stage of grinding and classification refers to the classification of hydrocyclones first and then the tower grinding; the third stage of grinding and classification refers to the classification of hydrocyclones and then the tower grinding; the first stage of grinding and classification Use a horizontal ball mill. 5. according to the described low-grade fine-grained embedded magnetite ore beneficiation method for improving quality and reducing impurities, it is characterized in that the pre-selected tailings obtained by the coarse-grained wet pre-selection described in the step (2) need to carry out classification treatment, classification treatment The obtained on-screen product is used as construction sand and gravel aggregate, and the under-screen product obtained by grading treatment is combined with the high-efficiency magnetic separation tailings of the first stage, the high-efficiency magnetic separation tailings of the second stage and the high-efficiency magnetic separation tails of the third stage. Mine is consolidated into total tailings. 6. The device for realizing the low-grade micro-grain embedded magnetite method for improving quality and reducing impurities according to claim 1, characterized in that the device comprises a belt conveyor (1), an intelligent blockage clearing bin (2), a hopper (3) ), high-pressure roller mill (4), high-efficiency fine powder sieve (6), batching bin (6.1), permanent magnet wet coarse-grain pre-separation magnetic separator (7), dewatering screen (9), first hydrocyclone ( 11), the first high-efficiency permanent magnet wet magnetic separator (14), the first pump pool (17), the second slurry pump (18), the second hydrocyclone (20), the second high-efficiency permanent magnet wet magnetic The separator (23), the second pump pool (24), the third hydrocyclone (27), the third slurry pump (29), the third high-efficiency permanent magnet wet magnetic separator (31), the lower feeding The second tower mill (36), the concentrate filter press (33), the fourth row of tail pipes (37), the third throwing tail pipe (38), the first tower mill (39) for the upper feed, the first Two rows of tail pipes (40), a first slurry pump (41), a third pump pool (42), a total tailings pipe (44) and a ball mill (45); the belt conveyors (1) are respectively connected to the The intelligent clearing silo (2), the hopper (3) and the high pressure roller mill (4), the high pressure roller mill (4) is connected to the high-efficiency fine powder sieve (6) through a pipeline, the The high-efficiency fine powder sieve (6) is connected to the batching bin (6.1), and the batching bin (6.1) is connected to the permanent magnet wet-type coarse-grain pre-separation magnetic separator (7) through a sixteenth pipeline (6.2). The permanent magnet wet coarse pre-separation magnetic separator (7) is respectively connected to the dewatering screen (9) and the ball mill (45) through pipelines; the dewatering screen (9) is connected to the total tailings pipe (9) through pipelines. 44), the ball mill (45) is connected to the third pump pool (42) through the fifteenth pipeline (43), and the third pump pool (42) passes through the first slurry pump (41) and The second pipeline (12) is connected to the first hydrocyclone (11), and the first hydrocyclone (11) is connected to the ball mill (45) through the first pipeline (10); A hydrocyclone (11) is connected to the first high-efficiency permanent magnet wet magnetic separator (14) through a third pipeline (13), and the first high-efficiency permanent magnet wet magnetic separator (14) passes through the first high-efficiency permanent magnet wet magnetic separator (14). The second tailing pipe (40) is connected to the general tailings pipe (44), and the first high-efficiency permanent magnet wet magnetic separator (14) is connected to the first pump pool (17) through a fifth pipeline (16). , the first pump pool (17) is connected to the second hydrocyclone (20) through the second slurry pump (18) and the sixth pipeline (19), the second hydrocyclone (20) The first column mill (39) of the upper feed is connected through a seventh pipeline (21), and the first column mill (39) of the upper feed is connected through a fourth pipeline (15) The first pump pool (17) and the second hydrocyclone (20) are connected to a second high-efficiency permanent magnet wet magnetic separator (23) through an eighth pipeline (22), and the second high-efficiency permanent magnet The wet magnetic separator (23) is connected to the total tailings pipe (44) through the third throwing tailing pipe (38) , the second high-efficiency permanent magnet wet magnetic separator (23) is connected to the second pump pool (24) through a ninth pipeline (25), and the second pump pool (24) passes through the third slurry The pump (29) is connected to the third hydrocyclone (27) through the tenth pipeline (26), and the third hydrocyclone (27) is connected to the lower supply through the twelfth pipeline (30). The second tower mill (36) for feed, the second tower mill (36) for the lower feed is connected to the second pump pool (24) through the fourteenth pipeline (35), the third hydraulic The cyclone (27) is connected to the third high-efficiency permanent magnet wet magnetic separator (31) through eleven pipelines (28), and the third high-efficiency permanent magnet wet magnetic separator (31) passes through the fourth throwing The tail pipe (37) is connected to the general tailings pipe (44), and the third high-efficiency permanent magnet wet magnetic separator (31) is connected to the concentrate filter press (33) through thirteen pipelines (32).

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