Dry separation and purification method based on magnet tailings

Abstract

The invention discloses a dry separation and purification method based on magnet tailings, relates to the technical field of mineral separation, and can solve the problems that in the prior art, the quality of concentrate screened by an existing screening method is difficult to improve, and a large amount of water resources are wasted. The method aims at conducting screening, magnetic separation and purification operation on the magnet tailings. The whole treatment process is carried out in a dry environment, water resource input is not needed, and use of an ore grinding system in a traditional ore dressing process is effectively avoided. In the magnetic separation process, an operator can accurately regulate and control the magnetic field intensity in each dry magnetic separator, so that accurate magnetic separation and screening of ores with different volumes and iron contents are realized. And after the magnetic separation operation is completed, the obtained finished products of fine iron powder, granite, pebbles 12, pebbles 13 and waste materials can be efficiently conveyed through the matching of each set of auger equipment and a sealing pipeline, so that the reasonable classification and collection of various products and waste materials are ensured.

Description

Technical Field

[0001] The invention relates to the technical field of ore dressing, and in particular to a dry separation and purification method based on magnetite tailings. Background Art

[0002] Mineral resources are an indispensable material basis for the survival and development of human society. It is not only an important source of people's living materials, but also an extremely important social means of production. However, most of my country's iron ore resources are of low grade and must be crushed, ground and sorted to obtain concentrate before they can be smelted. Generally speaking, iron tailings refer to the solid waste discharged after the ore is crushed, screened, ground, graded, and then re-selected, magnetically separated (or flotation) and chemically separated under specific economic and technical conditions. The large-scale storage of solid wastes such as tailings not only occupies a large amount of land, but also the useful components in the tailings cannot be fully utilized, resulting in a waste of resources. In the past mining process, due to the limitations of development and utilization technology, backward equipment and other factors, a large number of valuable elements were abandoned along with the tailings. Therefore, tailings have huge potential utilization value. At present, most valuable minerals have not yet been effectively dissociated, and the recovery rate of iron in tailings is generally higher than 50%. If the re-selection and recovery of this part of iron in the tailings is ignored, it will lead to a serious waste of resources. However, the current utilization rate of tailings is extremely low because the iron recovered from tailings often fails to meet the standards of high-quality iron ore concentrate, which in turn affects its selling price and market demand.

[0003] In reality, there are many methods for tailings salvage. However, the quality of the concentrate screened by this method is difficult to improve. The grade of iron concentrate is generally difficult to exceed 50%, and the recovery rate of these methods is generally less than 20% relative to the recovery rate of iron in tailings. In addition, these sorting methods also consume a lot of water resources. The ore mixture and water must be mixed into a liquid mixture in a certain proportion to complete the extraction and separation of the target elements in the ore. The above methods are not only difficult to improve the quality of the concentrate, but also cause a huge waste of water resources. Summary of the invention

[0004] In order to solve the problem in the prior art that the quality of iron concentrate screened out by the existing screening method is difficult to improve and a large amount of water resources are wasted, the present application provides a dry separation and purification method based on magnetite tailings to solve the above problems.

[0005] In order to achieve the above purpose, the technical solution adopted in this application is:

[0006] A dry separation and purification method based on magnetite tailings comprises the following steps:

[0007] S10: screening and filtering the magnetite tailings with screening equipment to remove impurities, and sending the tailings to a press in a workshop material table to obtain an ore mixture;

[0008] S20: The ore mixture is fed into the first dry magnetic separator through a conveying device to magnetically separate large ores and small ores, and then the small ores are fed to the second dry magnetic separator to magnetically separate iron ore with a grade greater than 18%, rice stone, 12 stone, 13 stone, and sand with a lower iron content;

[0009] S30: transporting the iron ore concentrate with a grade of more than 18% to the material platform of the second workshop, and magnetically separating the stones and powder in the iron ore concentrate by the third dry magnetic separator, and then crushing the iron ore concentrate by a hammer crushing device to obtain iron ore concentrate powder;

[0010] S40: The iron ore concentrate is transported to the fourth dry magnetic separator for magnetic separation, and then the iron ore concentrate obtained by magnetic separation is inspected. The iron ore concentrate with a grade greater than 60% is a finished product; the iron ore concentrate with a grade between 30% and 60% is a semi-finished product, which is fed back to the fourth dry magnetic separator through an auger and a sealed pipeline for secondary magnetic separation. The remaining waste after magnetic separation is transported and collected through a waste pipeline;

[0011] S50: Purify the finished iron ore concentrate using an air separation device to obtain purified iron ore concentrate.

[0012] As a further improvement of the present invention, in step S10, the screening equipment is a mud-rock separator, and the screened and filtered ore is sent to a press in a material table in a workshop by a belt conveyor.

[0013] As a further improvement of the present invention, the magnetic field strength of the first dry magnetic separator in step S20 is set to 6000GS-10000GS, the rotation speed is set to 30-70r / min, and the conveying device is a belt conveyor.

[0014] As a further improvement of the present invention, the magnetic field strength of the second dry magnetic separator in step S20 is set to 3000GS-5000GS, and the speed is set to 28-45r / min.

[0015] As a further improvement of the present invention, the magnetic field strength of the third dry magnetic separator in step S30 is set to 3000GS-4800GS, the rotation speed is set to 28-55r / min, and the hammer in the hammer crushing device is a flat head.

[0016] As a further improvement of the present invention, the step S40 also includes a fifth dry magnetic separator. When the iron ore concentrate in step S30 is wet, the wet iron ore concentrate is first sent to the fourth dry magnetic separator for magnetic separation through the first auger and the sealed pipe, and is dried at the same time. Then, the dried iron ore concentrate is sent to the fifth dry magnetic separator through the fifth auger and the sealed pipe, and then magnetically separated for the second time to finally obtain the finished iron ore concentrate.

[0017] As a further improvement of the present invention, the magnetic field strength of the fourth dry magnetic separator in step S40 is set to 5000GS-6000GS, and the rotation speed is set to 28-55r / min.

[0018] As a further improvement of the present invention, the magnetic field strength of the fifth dry magnetic separator in step S40 is set to 6000GS-8000GS, and the rotation speed is set to 28-55r / min.

[0019] As a further improvement of the present invention, the air separation device in step S50 uses a sand and stone air separation machine, and utilizes the different suspension speeds of different light impurities, light fine particles and iron ore concentrate in the finished iron ore concentrate to purify the iron ore concentrate to obtain purified iron ore concentrate.

[0020] Compared with the prior art, the technical solution provided by the present invention has the following advantages and effects:

[0021] 1. In this application, a screening method including steps S10 to S50 is used to implement screening, magnetic separation and purification operations on magnet tailings. The entire process is carried out in a dry environment, without the need for water resources, and effectively avoids the use of grinding systems in traditional mineral processing processes. For the iron ore concentrate obtained after magnetic separation, we specially introduced a hammer crushing device for crushing. In this process, the operator can accurately control the magnetic field strength inside each dry magnetic separator to achieve accurate magnetic separation and screening of ores of different volumes and iron contents. When the magnetic separation operation is completed, the obtained finished iron ore concentrate, rice stone, 12 stones, 13 stones and waste can be efficiently transported through the equipped various auger equipment in conjunction with sealed pipes to ensure the reasonable classification and collection of various products and waste. For the magnetically selected iron ore concentrate, it will be directly transported to the storage warehouse or further processing workshop through the auger in conjunction with the sealed pipe, effectively preventing the loss and pollution of the iron ore concentrate during transportation. Rice stone, 12-grain stone and 13-grain stone are collected and classified according to their particle size and physical properties, and then used as building materials, road paving materials or further processed into raw materials for other high value-added products, thus realizing the recycling of resources. As for the waste generated during the magnetic separation process, the waste is preliminarily classified and screened to remove the recyclable materials, and then recycled. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative labor.

[0023] Figure 1 The present invention is a schematic diagram of the process of screening iron concentrate from magnetite tailings. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0026] It should be understood that the embodiments of the present invention shown in the exemplary embodiments are only illustrative. Although only a few embodiments are described in detail in the present invention, it is easy for those skilled in the art to appreciate that multiple modifications are feasible without actually departing from the teaching of the subject matter of the present invention. Accordingly, all such modifications should be included within the scope of the present invention. Without departing from the gist of the present invention, other replacements, modifications, changes and deletions may be made to the design, operating conditions and parameters of the following exemplary embodiments.

[0027] like Figure 1 As shown, the present invention provides a dry separation and purification method based on magnetite tailings, comprising the following steps:

[0028] S10: Screening equipment is used to screen and filter the magnetite tailings to remove sand, fine plastic debris and mud from the magnetite tailings. The screened and filtered ore is then sent to a press in a workshop material table through a conveying device, and then crushed and shaped to obtain an ore mixture.

[0029] It should be noted that in the continuous process of ore processing, screening and filtration is the initial step. In this step, non-target substances in the ore, such as sand, fine plastics and mixed mud, can be effectively distinguished and removed. If these impurities enter the subsequent processing flow without being treated, it will not only reduce product quality, but may also cause wear and tear on production equipment and increase maintenance costs.

[0030] Furthermore, the purity of the ore after screening and filtration is significantly improved, and these selected ores are transported to the press in the material table of a workshop through a stable conveying device. This link ensures the continuity and stability of the production line, avoids material accumulation or delays, and thus improves the overall production efficiency.

[0031] S20: The ore mixture is sent to the first dry magnetic separator through a conveying device, and the large pieces of ore and the small pieces of ore are magnetically separated by controlling the power of the first dry magnetic separator. Then the small pieces of ore are transported to the second dry magnetic separator, and the power of the second dry magnetic separator is controlled to magnetically separate iron ore with a grade greater than 18%, rice stone, 12 stone, 13 stone and sand with a lower iron content.

[0032] It should be noted that rice stone, 12-stone and 13-stone have broad application prospects as construction or road paving materials. After screening, we will grade and screen them according to market demand to ensure that the particle size of each category of gravel is uniform to meet different engineering requirements. Sand with less iron content: Although the iron content of this part of the product is low, it still has certain economic value. The processed sand can be used in concrete production, beach restoration, water conservancy projects and other fields to maximize the utilization of resources.

[0033] S30: The iron ore concentrate with a grade of more than 18% is transported to the material platform of the second workshop, and the stones and powder in the iron ore concentrate are magnetically separated by the third dry magnetic separator. Then, the iron ore concentrate is sent to the inside of the hammer crushing device, and the iron ore concentrate is crushed by the hammer crushing device to obtain iron ore concentrate powder.

[0034] Specifically, in the preparation process of iron ore concentrate, the particle size of the iron ore concentrate that has been finely processed by the hammer crushing device is effectively controlled within a specific range, ensuring the stability of subsequent processes and the uniformity of product quality. The crushing device includes 108 flat hammers and is equipped with four motors. The stones are hit by the flat hammers to reduce the particle size of the ore, and the motor has an adjustable speed that can be adjusted according to the coarseness of the ore. When the ore is fine, the speed can be increased to increase the number of heavy blows, thereby crushing the stone more finely. When the ore is coarse, the speed can be lowered to allow the flat head to have more sufficient contact with the stone, thereby quickly crushing the stone.

[0035] S40: The iron ore concentrate is transported to the fourth dry magnetic separator through the first auger and the sealed pipeline, and is magnetically separated by the fourth dry magnetic separator. The iron ore concentrate obtained by the magnetic separation is then inspected. The iron ore concentrate with a grade greater than 60% is the finished product, which is directly transported and collected through the second auger and the sealed pipeline; the iron ore concentrate with a grade between 30% and 60% is the semi-finished product, which is returned to the fourth dry magnetic separator for secondary magnetic separation through the third auger and the sealed pipeline, and the remaining waste after the magnetic separation is transported and collected through the fourth auger and the sealed pipeline.

[0036] It is explained that the initial transportation of iron ore concentrate, through the cooperation of the first auger and the sealed pipe, can effectively prevent the scattering and contamination of the iron ore concentrate during the transportation process, and also ensure that the material can continuously and evenly enter the fourth dry magnetic separator. At the same time, the use of sealed pipes reduces the escape of dust, greatly improves the production environment, and ensures the health and safety of operators.

[0037] Furthermore, the fourth dry magnetic separator effectively separates the magnetic substances from the non-magnetic substances in the iron ore concentrate through the action of the magnetic field, thus achieving the purification of the iron ore concentrate. In this process, the precise control of magnetic separation parameters, such as magnetic field strength and rotation speed, is particularly important. The adjustment of these parameters needs to be flexibly carried out according to the properties of the raw materials and the requirements of the target products to achieve the best magnetic separation effect.

[0038] For the iron ore concentrate separated by magnetic separation, the grade of the iron ore concentrate is accurately determined by professional testing equipment. When the grade is greater than 60%, this batch of iron ore concentrate is the finished product, and then it is directly transported to the collection area through the cooperation of the second auger and the sealed pipe again. For the semi-finished products with a grade between 30% and 60%, we have not given up their potential value. Through the ingenious design of the third auger and the sealed pipe, these semi-finished products are fed back to the fourth dry magnetic separator for secondary magnetic separation. This step makes full use of equipment resources, improves the utilization rate of raw materials, and also provides the possibility of producing higher-grade iron ore concentrate. During the secondary magnetic separation process, it may be necessary to adjust the magnetic separation parameters or adopt other auxiliary means to ensure that the semi-finished products can be fully purified to meet the expected grade requirements.

[0039] Finally, we also pay enough attention to the treatment of waste after magnetic separation. Through the fourth auger and the sealed pipeline, these wastes are collected in an orderly manner and prepared for subsequent treatment or recycling. Reasonable treatment of waste not only helps to reduce environmental pollution, but also brings certain economic benefits to the enterprise.

[0040] S50: Purify the finished iron ore concentrate by means of an air separation device, remove light impurities and light fine particles in the finished iron ore concentrate, and obtain purified iron ore concentrate.

[0041] It is explained that the air separation device mainly uses the principles of aerodynamics to create a flow field environment suitable for the separation of light impurities and light fine particles in a specific air separation chamber by precisely controlling the wind speed and wind direction. When the finished iron ore concentrate is sent into the air separation chamber, particles of different densities show different movement trajectories due to the different wind forces. Heavy particles (i.e. the main body of iron ore concentrate) tend to fall along a straight line or a small deflection path due to their greater inertia; while light impurities and fine particles, because the wind force they are subjected to is much greater than their own gravity, will experience a large deflection or even be completely blown away, thereby effectively separating from the heavy particles.

[0042] It is worth noting that the quality of the iron ore concentrate purified by the air separation device has been significantly improved. First, the effective removal of light impurities and light fine particles significantly reduces the ash and impurity content of the product, improves the iron grade, and makes the purified iron ore concentrate more in line with the requirements of subsequent processing. Secondly, the improvement of purity also means the enhancement of product performance, which is conducive to the smooth progress of the upstream and downstream production processes of the industry.

[0043] In step S10 of the above method, the screening equipment is a mud-rock separator, and the screened and filtered ore is sent to a press in a material table in a workshop by a belt conveyor.

[0044] In step S20 of the above method, the magnetic field strength of the first dry magnetic separator is set to 6000GS-10000GS, the rotation speed is set to 30-70r / min, and the conveying device is a belt conveyor.

[0045] The magnetic field strength of the second dry magnetic separator in step S20 of the above method is set to 3000GS-5000GS, and the speed is set to 28-45r / min.

[0046] The magnetic field strength of the third dry magnetic separator in step S30 of the above method is set to 3000GS-4800GS, the rotation speed is set to 28-55r / min, and the hammer head in the hammer head crushing device is a flat head.

[0047] Step S40 of the above method also includes a fifth dry magnetic separator. When the iron ore concentrate in step S30 is wet, the wet iron ore concentrate is first sent to the fourth dry magnetic separator for magnetic separation through the first auger and the sealed pipe, and dried at the same time. Then, the dried iron ore concentrate is sent to the fifth dry magnetic separator through the fifth auger and the sealed pipe, and then magnetically separated for the second time to finally obtain the finished iron ore concentrate.

[0048] In step S40 of the above method, the magnetic field strength of the fourth dry magnetic separator is set to 5000GS-6000GS, and the rotation speed is set to 28-55r / min.

[0049] In step S40 of the above method, the magnetic field strength of the fifth dry magnetic separator is set to 6000GS-8000GS, and the rotation speed is set to 28-55r / min.

[0050] The air separation device in step S50 of the above method uses a sand and stone air separator, and utilizes the different suspension speeds of different light impurities, light fine particles and iron ore concentrate in the finished iron ore concentrate to purify the iron ore concentrate to obtain purified iron ore concentrate.

[0051] The above technical solution of the present invention is described in detail below through specific embodiments.

[0052] Example 1-When the ore mixture is dry material:

[0053] A dry separation and purification method based on magnetite tailings, the specific steps are as follows:

[0054] Step 1: The operator first transports the accumulated magnetite tailings to the mud-rock separator, and removes the sand, fine plastic debris and mud in the magnetite tailings through the mud-rock separator. Then, the screened and filtered ore is sent to the press in the material table of a workshop through a belt conveyor, and then it is crushed and shaped to obtain an ore mixture;

[0055] Step 2: The ore mixture is then conveyed to the first dry magnetic separator with a magnetic field strength of 6000GS and a rotation speed of 30r / min by a belt conveyor for magnetic separation, and large pieces of ore and small pieces of ore are magnetically separated respectively. Then, the small pieces of ore are conveyed to the second dry magnetic separator with a magnetic field strength of 3000GS and a rotation speed of 28r / min by a belt conveyor for magnetic separation, and finally ironstone, rice stone, 12 stones, 13 stones and sand with a low iron content having a grade greater than 18% are selected. Among them, rice stone, 12 stones, 13 stones and sand with a low iron content can be properly formulated on the basis of secondary recycling, so that they can be used as raw materials for many building materials and have certain economic value.

[0056] Step 3: The iron ore with a grade greater than 18% is transported to the material table of the second workshop, and then enters the third dry magnetic separator with a magnetic field strength of 3000GS and a rotation speed of 28r / min for magnetic separation, and the iron ore blocks and iron ore powder are magnetically separated. The iron ore blocks are then sent to the hammer crushing device, and the iron ore blocks are crushed by the crushing device to obtain more broken powder.

[0057] Step 4: The first auger is arranged between the hammer crushing device and the fourth dry magnetic separator. The crushed iron ore concentrate is transported through the first auger to the fourth dry magnetic separator with a magnetic field strength of 5000GS and a rotation speed of 28r / min for magnetic separation. Subsequently, the operator conducts a grade test on the iron ore concentrate after magnetic separation. The iron ore concentrate with a grade greater than 60% is a finished product, which is directly transported and collected through the second auger in conjunction with a sealed pipeline; the iron ore concentrate with a grade between 30% and 60% is a semi-finished product, which is returned to the fourth dry magnetic separator through the third auger in conjunction with a sealed pipeline for secondary magnetic separation. The remaining waste materials after magnetic separation are transported and collected through the fourth auger in conjunction with a sealed pipeline.

[0058] Step 5: The finished iron ore concentrate is directly transported and collected through the second auger and the sealed pipeline, and then the collected iron ore concentrate is transported to the sand and gravel air separator. The iron ore concentrate is purified by utilizing the different light impurities, light fine particles and different suspension speeds of the iron ore concentrate in the finished iron ore concentrate to obtain the purified iron ore concentrate.

[0059] Example 2-When the ore mixture is dry material:

[0060] A dry separation and purification method based on magnetite tailings, the specific steps are as follows:

[0061] Step 1: The operator first transports the accumulated magnetite tailings to the mud-rock separator, and removes the sand, fine plastic debris and mud in the magnetite tailings through the mud-rock separator. Then, the screened and filtered ore is sent to the press in the material table of a workshop through a belt conveyor, and then it is crushed and shaped to obtain an ore mixture;

[0062] Step 2: The ore mixture is then conveyed by a belt conveyor to the first dry magnetic separator with a magnetic field strength of 10000GS and a rotation speed of 70r / min for magnetic separation, and large pieces of ore and small pieces of ore are magnetically separated respectively. Then, the small pieces of ore are conveyed by a belt conveyor to the second dry magnetic separator with a magnetic field strength of 5000GS and a rotation speed of 45r / min for magnetic separation, and finally iron ore with a grade greater than 18%, rice stone, 12 stone, 13 stone and sand with a low iron content are selected.

[0063] Step 3: The iron ore with a grade greater than 18% is transported to the material table of the second workshop, and then enters the third dry magnetic separator with a magnetic field strength of 4800GS and a rotation speed of 55r / min for magnetic separation, and the iron ore blocks and iron ore powder are magnetically separated. The iron ore blocks are then sent to the hammer crushing device, and the iron ore blocks are crushed by the crushing device to obtain more broken powder.

[0064] Step 4: The first auger is arranged between the hammer crushing device and the fourth dry magnetic separator. The crushed iron ore concentrate is transported through the first auger to the fourth dry magnetic separator with a magnetic field strength of 6000GS and a rotation speed of 55r / min for magnetic separation. Subsequently, the operator conducts a grade test on the iron ore concentrate after magnetic separation. The iron ore concentrate with a grade greater than 60% is a finished product, which is directly transported and collected through the second auger in conjunction with a sealed pipeline; the iron ore concentrate with a grade between 30% and 60% is a semi-finished product, which is returned to the fourth dry magnetic separator through the third auger in conjunction with a sealed pipeline for secondary magnetic separation. The remaining waste materials after magnetic separation are transported and collected through the fourth auger in conjunction with a sealed pipeline.

[0065] Step 5: The finished iron ore concentrate is directly transported and collected through the second auger and the sealed pipeline, and then the collected iron ore concentrate is transported to the sand and gravel air separator. The iron ore concentrate is purified by utilizing the different light impurities, light fine particles and different suspension speeds of the iron ore concentrate in the finished iron ore concentrate to obtain the purified iron ore concentrate.

[0066] Example 3 - When the ore mixture is wet material:

[0067] A dry separation and purification method based on magnetite tailings, the specific steps are as follows:

[0068] Step 1: The operator first transports the accumulated magnetite tailings to the mud-rock separator, and removes the sand, fine plastic debris and mud in the magnetite tailings through the mud-rock separator. Then, the screened and filtered ore is sent to the press in the material table of a workshop through a belt conveyor, and then it is crushed and shaped to obtain an ore mixture;

[0069] Step 2: The ore mixture is then conveyed by a belt conveyor to the first dry magnetic separator with a magnetic field strength of 6000GS and a rotation speed of 30r / min for magnetic separation, and large pieces of ore and small pieces of ore are magnetically separated respectively. Then, the small pieces of ore are conveyed by a belt conveyor to the second dry magnetic separator with a magnetic field strength of 3000GS and a rotation speed of 28r / min for magnetic separation, and finally iron ore with a grade greater than 18%, rice stone, 12 stone, 13 stone and sand with a low iron content are selected.

[0070] Step 3: The iron ore with a grade greater than 18% is transported to the material table of the second workshop, and then enters the third dry magnetic separator with a magnetic field strength of 3000GS and a rotation speed of 28r / min for magnetic separation, and the iron ore blocks and iron ore powder are magnetically separated. The iron ore blocks are then sent to the hammer crushing device, and the iron ore blocks are crushed by the crushing device to obtain more broken powder.

[0071] Step 4: The first auger is arranged between the hammer crushing device and the fourth dry magnetic separator. The wet iron powder crushed into powder is first transported by the first auger to the fourth dry magnetic separator with a magnetic field strength of 5000GS and a rotation speed of 28r / min for magnetic separation, and is dried at the same time to remove moisture in the wet iron powder. Subsequently, the dried iron powder is transported to the fifth dry magnetic separator with a magnetic field strength of 6000GS and a rotation speed of 28r / min through the fifth auger in conjunction with a sealed pipeline, and then magnetically separated for the second time. The iron powder finally separated by magnetic separation is graded and tested by the operator. The iron powder with a grade greater than 60% is a finished product, which is directly transported and collected through the second auger in conjunction with a sealed pipeline; the iron powder with a grade between 30% and 60% is a semi-finished product, which is returned to the fourth dry magnetic separator through the third auger in conjunction with a sealed pipeline for secondary magnetic separation, and the remaining waste materials after magnetic separation are transported and collected through the fourth auger in conjunction with a sealed pipeline.

[0072] Step 5: The finished iron ore concentrate is directly transported and collected through the second auger and the sealed pipeline, and then the collected iron ore concentrate is transported to the sand and gravel air separator. The iron ore concentrate is purified by utilizing the different light impurities, light fine particles and different suspension speeds of the iron ore concentrate in the finished iron ore concentrate to obtain the purified iron ore concentrate.

[0073] Example 4 - When the ore mixture is wet:

[0074] A dry separation and purification method based on magnetite tailings, the specific steps are as follows:

[0075] Step 1: The operator first transports the accumulated magnetite tailings to the mud-rock separator, and removes the sand, fine plastic debris and mud in the magnetite tailings through the mud-rock separator. Then, the screened and filtered ore is sent to the press in the material table of a workshop through a belt conveyor, and then it is crushed and shaped to obtain an ore mixture;

[0076] Step 2: The ore mixture is then conveyed by a belt conveyor to the first dry magnetic separator with a magnetic field strength of 10000GS and a rotation speed of 70r / min for magnetic separation, and large pieces of ore and small pieces of ore are magnetically separated respectively. Then, the small pieces of ore are conveyed by a belt conveyor to the second dry magnetic separator with a magnetic field strength of 5000GS and a rotation speed of 45r / min for magnetic separation, and finally iron ore with a grade greater than 18%, rice stone, 12 stone, 13 stone and sand with a low iron content are selected.

[0077] Step 3: The iron ore with a grade greater than 18% is transported to the material table of the second workshop, and then enters the third dry magnetic separator with a magnetic field strength of 4800GS and a rotation speed of 55r / min for magnetic separation, and the iron ore blocks and iron ore powder are magnetically separated. The iron ore blocks are then sent to the hammer crushing device, and the iron ore blocks are crushed by the crushing device to obtain more broken powder.

[0078] Step 4: The first auger is arranged between the hammer crushing device and the fourth dry magnetic separator. The wet iron powder crushed into powder is first transported by the first auger to the fourth dry magnetic separator with a magnetic field strength of 5000GS and a rotation speed of 28r / min for magnetic separation, and is dried at the same time to remove moisture in the wet iron powder. Subsequently, the dried iron powder is transported to the fifth dry magnetic separator with a magnetic field strength of 8000GS and a rotation speed of 55r / min through the fifth auger in conjunction with a sealed pipeline, and then subjected to secondary magnetic separation. The iron powder finally magnetically separated is graded by the operator, and the iron powder with a grade greater than 60% is a finished product, which is directly transported and collected through the second auger in conjunction with a sealed pipeline; the iron powder with a grade between 30% and 60% is a semi-finished product, which is returned to the fourth dry magnetic separator through the third auger in conjunction with a sealed pipeline for secondary magnetic separation, and the remaining waste after magnetic separation is transported and collected through the fourth auger in conjunction with a sealed pipeline.

[0079] Step 5: The finished iron ore concentrate is directly transported and collected through the second auger and the sealed pipeline, and then the collected iron ore concentrate is transported to the sand and gravel air separator. The iron ore concentrate is purified by utilizing the different light impurities, light fine particles and different suspension speeds of the iron ore concentrate in the finished iron ore concentrate to obtain the purified iron ore concentrate.

[0080] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A dry separation and purification method based on magnetite tailings, characterized in that: The following steps are involved: S10: screening and filtering the magnetite tailings with screening equipment to remove impurities, and sending the tailings to a press in a workshop material table to obtain an ore mixture; S20: The ore mixture is fed into the first dry magnetic separator through a conveying device to magnetically separate large ores and small ores, and then the small ores are fed to the second dry magnetic separator to magnetically separate iron ore with a grade greater than 18%, rice stone, 12 stone, 13 stone, and sand with a lower iron content; S30: transporting the iron ore concentrate with a grade of more than 18% to the material platform of the second workshop, and magnetically separating the stones and powder in the iron ore concentrate by the third dry magnetic separator, and then crushing the iron ore concentrate by a hammer crushing device to obtain iron ore concentrate powder; S40: The iron ore concentrate is transported to the fourth dry magnetic separator for magnetic separation, and then the iron ore concentrate obtained by magnetic separation is inspected. The iron ore concentrate with a grade greater than 60% is a finished product; the iron ore concentrate with a grade between 30% and 60% is a semi-finished product, which is fed back to the fourth dry magnetic separator through an auger and a sealed pipeline for secondary magnetic separation. The remaining waste after magnetic separation is transported and collected through a waste pipeline; S50: Purify the finished iron ore concentrate using an air separation device to obtain purified iron ore concentrate.

2. A dry separation and purification method based on magnetite tailings according to claim 1, characterized in that: In the step S10, the screening equipment is a mud-rock separator, and the screened and filtered ore is sent to a press in a material table in a workshop by a belt conveyor.

3. A dry separation and purification method based on magnetite tailings according to claim 1, characterized in that: The magnetic field strength of the first dry magnetic separator in step S20 is set to 6000GS-10000GS, the rotation speed is set to 30-70r / min, and the conveying device is a belt conveyor.

4. A dry separation and purification method based on magnetite tailings according to claim 3, characterized in that: The magnetic field strength of the second dry magnetic separator in step S20 is set to 3000GS-5000GS, and the rotation speed is set to 28-45r / min.

5. A dry separation and purification method based on magnetite tailings according to claim 1, characterized in that: The magnetic field strength of the third dry magnetic separator in step S30 is set to 3000GS-4800GS, the rotation speed is set to 28-55r / min, and the hammer head in the hammer head crushing device is a flat head.

6. A dry separation and purification method based on magnetite tailings according to claim 1, characterized in that: The step S40 also includes a fifth dry magnetic separator. When the iron ore concentrate in step S30 is wet, the wet iron ore concentrate is first sent to the fourth dry magnetic separator for magnetic separation through the first auger and the sealed pipe, and is dried at the same time. Then, the dried iron ore concentrate is sent to the fifth dry magnetic separator through the fifth auger and the sealed pipe, and then magnetically separated for the second time to finally obtain the finished iron ore concentrate.

7. A dry separation and purification method based on magnetite tailings according to claim 6, characterized in that: In the step S40, the magnetic field strength of the fourth dry magnetic separator is set to 5000GS-6000GS, and the rotation speed is set to 28-55r / min.

8. A dry separation and purification method based on magnetite tailings according to claim 7, characterized in that: In the step S40, the magnetic field strength of the fifth dry magnetic separator is set to 6000GS-8000GS, and the rotation speed is set to 28-55r / min.

9. A dry separation and purification method based on magnetite tailings according to claim 1, characterized in that: The air separation device in step S50 is a sand and stone air separator, which utilizes the different suspension speeds of different light impurities, light fine particles and iron ore concentrate in the finished iron ore concentrate to purify the iron ore concentrate to obtain purified iron ore concentrate.

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