A new process for cooperative mining of tailings and comprehensive utilization in iron ore tailings reservoir

Abstract

The application discloses a new process for cooperatively mining tailings and comprehensive utilization in an iron ore tailings pond, adopts a dry mining and wet mining combined process, and obtains coarse tailings with a size of greater than or equal to 5 mm, medium-grained tailings sand with a size of 2-5 mm, fine-grained tailings sand with a size of 0.5-2 mm and iron concentrate powder with TFe not lower than 60.0% through screening and magnetic separation operations, feeds the new tailings after the magnetic separation into a classifier set (8), discharges fine-grained slurry which is concentrated and pressed into fine slurry cakes by a filter press (12), crushes the fine slurry cakes through an environmental protection double-shaft feeding crusher (18), and stirs the fine slurry cakes into cement and building aggregates to enter a brick making machine (19) to make bricks. The application solves the problem of the storage of the iron ore tailings pond, and has high mining efficiency. The cooperatively mining and comprehensive utilization classify the tailings into coarse tailings, medium tailings, fine tailings and tailings mud, and improve the utilization efficiency of the iron tailings resources. In combination with the tailings mining, impurity removal, classification, concentration, filter pressing and resource utilization processes, the system is circularly used, the operation efficiency is improved, and resource waste is reduced.

Description

Technical Field

[0001] This invention belongs to the field of tailings recovery and utilization technology, specifically involving a new process for the coordinated recovery and comprehensive utilization of tailings in iron ore tailings ponds. Background Technology

[0002] my country is the world's largest steel producer. Long-term, high-intensity mining of iron ore resources has led to massive tailings emissions and a continuously rising accumulation. According to statistics, my country's cumulative iron ore tailings have exceeded 10 billion tons, and are still increasing by hundreds of millions of tons annually. Iron ore tailings ponds, as the core facilities for tailings storage, are not only classified as major safety hazards, prone to dam failures and leaks that threaten people's lives and property, but also occupy vast amounts of land resources. Furthermore, the harmful substances remaining in iron ore tailings can easily cause soil and groundwater pollution, and the unrecovered iron elements and associated valuable metals and non-metallic minerals are wasted, severely hindering the sustainable development of the iron ore industry.

[0003] Currently, promoting the resource utilization of iron ore tailings and reducing the safety risks of iron ore tailings ponds are key measures for practicing green mining and ecological civilization construction. However, existing iron ore tailings treatment technologies have significant shortcomings. The core problem is the disconnect between the mining and utilization stages, and the imbalance between safety assurance and economic benefits. In the iron ore tailings mining stage, existing technologies mostly adopt single dry or wet mining modes, which are poorly adapted to the complex stockpile structure of tailings ponds (such as layered sedimentation, particle size segregation, and uneven consolidation), resulting in low mining efficiency. At the same time, the accuracy of detecting the distribution of valuable elements in the tailings is insufficient, and there is a lack of real-time grade identification methods, which easily leads to ineffective mining and seriously affects the economics of mining.

[0004] In the comprehensive utilization of iron ore tailings, existing technologies lack a systematic and coordinated approach. The secondary recovery of low-grade iron and associated valuable metals in iron ore tailings is difficult, consumes a lot of reagents, and has a high overall cost. For iron ore tailings components with no recovery value, simple stockpiling or landfilling methods are often used, without fully exploring their comprehensive utilization potential and resulting in limited disposal capacity.

[0005] Furthermore, the lack of coordination between the mining process and environmental protection measures, and improper control of mining disturbance, mud transportation, dewatering and dry discharge, can easily lead to secondary pollution problems such as dust, wastewater overflow, and heavy metal migration, making it impossible to achieve the integrated goal of "safe mining, resource recovery and ecological governance".

[0006] Currently, the comprehensive utilization rate of iron ore tailings in my country is still at a low level, far from meeting the requirements of relevant national industries. Therefore, it is urgent to develop a new process that can achieve safe tailings dam recovery, efficient recycling of valuable resources, and large-scale comprehensive utilization of tailings in a coordinated manner. This has become an urgent need to solve the pain points of industry development and help the iron ore industry transform towards green and resource-oriented directions. Summary of the Invention

[0007] The purpose of this invention is to address the technical challenges of existing technologies, such as poor adaptability to the complex storage structure of tailings ponds, low mining efficiency, lack of systematic collaborative thinking, high overall cost, and low tailings utilization rate, by providing a new process for collaborative mining and comprehensive utilization of tailings in iron ore tailings ponds.

[0008] To achieve the above-mentioned objectives of this invention, a novel process for the co-mining and comprehensive utilization of tailings in iron ore tailings ponds is characterized by the following steps:

[0009] S1, Recovery-Clean-up Pulping

[0010] The process combines dry mining and wet mining. Excavators are used to mine the tailings in the iron ore tailings pond, and a crushing, slurry making and slag separating machine is used to separate impurities from the water-containing tailings. The tailings after impurity removal are then pumped to the transfer pump pool by a float-type submersible slurry pump.

[0011] S2, Screening-Magnetic Separation Recovery

[0012] The tailings slurry in the transfer pump pool is fed into the screening operation via a tailings conveying pump. The screening operation adopts a multi-stage screening and recovery integrated machine with three screening grades and screen mesh sizes of 5mm, 2mm, and 0.5mm, respectively. The screening operation obtains coarse tailings ≥5mm, medium tailings sand 2-5mm, and fine tailings sand 0.5-2mm. The coarse tailings ≥5mm, medium tailings sand 2-5mm, and fine tailings sand 0.5-2mm are directly sold as building aggregate or construction sand products, and fine tailings sand with a particle size <0.5mm is discharged. The fine tailings sand <0.5mm is fed into a magnetic separator for magnetic separation to obtain iron concentrate powder with TFe of not less than 60.0%, and the new tailings from magnetic separation are discharged. The wastewater generated by magnetic separation is pumped into the wastewater pump pool by a wastewater pump.

[0013] S3, Combination Grading

[0014] The new tailings discharged from the magnetic separation in step S2 are fed into a classifying unit, which is arranged in series with a single spiral classifier, a high-frequency fine screen, and a hydrocyclone group. The underflow from the single spiral classifier is fed into the high-frequency fine screen, and the overflow product is coarse sand (underflow) with a particle size ≥ 0.1 mm. The underflow product is fed into the hydrocyclone group, which separates medium and fine sand (underflow) with a particle size of 0.075-0.1 mm. The mud content of the medium and fine sand is controlled within 3%. The separated coarse and medium and fine sand are dewatered by vibration and then transported to the sand storage area. The overflow products of the single spiral classifier and the hydrocyclone are combined into fine slurry. The hydrocyclone group consists of 3-5 hydrocyclones connected in parallel. The vibration frequency of the high-frequency fine screen is 2000-2500 r / min and the amplitude is 3-5 mm.

[0015] S4, Concentration-Pressure Filtration

[0016] The fine slurry discharged from step S3 is fed into a thickener. Flocculant is added to the thickener to allow sedimentation. The supernatant is then recycled into a return water pump pool and transported to a high-level water tank for continued use in water recovery. The slurry concentrated by the thickener is transported to the filter press feed hopper via a filter press feed pump. It is then pressed into fine mud cakes by the filter press, and excess water is separated. The cakes are then temporarily stored at the brick-making site. The water produced by the filter press enters the return water pump pool and is then transported to a high-level water tank for continued use in water recovery.

[0017] S5, Fine clay cake crushing and mixing - brick making

[0018] The fine mud cake obtained in step S4 is crushed by an environmentally friendly twin-shaft feeder and then mixed with cement and aggregates. After being fed into a brick making machine, it is pressed, extruded, and made into wet brick blanks. These blanks are then placed on a fixed platform and naturally cured to produce brick products.

[0019] Preferably, in step S5, the mass percentages of fine clay cake, aggregate, and cement are: fine clay cake 65%–77%, aggregate 10%–15%, and cement 13%–20%.

[0020] Preferably, in step S1, the crushing, pulping, and slag-filtering machine uses a high-manganese steel wear-resistant roller body equipped with a screen, and the screen aperture is selected as 8-12mm.

[0021] Preferably, in step S1, the float-type submersible slurry pump uses a corrosion-resistant polyurethane impeller and the float is made of high-density polyethylene.

[0022] Preferably, in step S2, the magnetic separator is a wet permanent magnet drum magnetic separator; the tailings conveying pump is a wear-resistant centrifugal pump with a conveying flow rate of 1.5 to 2.0 m / s.

[0023] Preferably, in step S4, the thickener is a high-efficiency deep cone thickener with a cone angle of 60-70° and multiple inclined plates inside.

[0024] Preferably, in step S4, the flocculant added to the thickener is anionic polyacrylamide (PAM) with a molecular weight of 8 million to 12 million, and the addition amount is 10 to 20 g / t, calculated based on the weight of the dry fine slurry being processed.

[0025] Preferably, in step S4, the filter press feed pump is a wear-resistant slurry pump, the return water pump is a pipeline pump, and the filter press is a horizontal quick-opening type equipped with a fully automatic control system and a mechanical scraper for cake discharge.

[0026] Preferably, in step S5, the rotor speed of the environmentally friendly twin-shaft feeding crusher is 300-400 r / min; the aggregate is iron ore tailings processed feed with a particle size of 0.5-10 mm and a moisture content of ≤5% after drying; and the cement is 32.5 grade ordinary Portland cement.

[0027] Preferably, in step S5, the brick-making machine is a fully automatic hydraulic type, the mold is flexibly adjusted according to market demand, the fixed platform is made of concrete, the fixed platform is surrounded by a guardrail ≥1.2m high, and the spacing between the green bricks is 5-10mm.

[0028] The new process for the coordinated mining and comprehensive utilization of tailings in iron ore tailings ponds, as described in this invention, has the following beneficial effects after adopting the above technical solution:

[0029] (1) This invention relies on the combined process of "dry mining + wet mining" and three-stage screening-magnetic separation. The process achieves precise capture of low-grade iron minerals in the tailings and obtains iron concentrate powder with TFe≥60.0% by magnetic separation. At the same time, the combined classification process further separates the new tailings from magnetic separation into coarse sand, medium and fine sand and fine mud, realizing dual fine control of particle size and grade, turning the originally abandoned low-grade resources into quantifiable products, significantly improving resource utilization and turning waste into treasure.

[0030] (2) During the mining process, the total amount of tailings dam accumulation is reduced simultaneously, the dam load is reduced, and safety hazards such as dam failure, seepage, and geological disasters are reduced; the land occupied by tailings storage is reduced, ecological and environmentally friendly production is achieved, and a safe closed loop of "mining-based governance" is realized.

[0031] (3) The new process connects the processes of mining and pulping, screening and magnetic separation, combined grading, thickening and filtration, and brick making into a continuous operation line, eliminating the intermediate storage and secondary transportation links that are disconnected between mining and utilization in the traditional process. The crushing and pulping separator removes impurities at the source, and the high-efficiency deep cone thickener, together with flocculants, achieves rapid separation of mud and water. The recycled water is recycled in a closed loop, and the overall process is compact, with significantly reduced energy and chemical consumption.

[0032] (4) The new process constructs a tiered utilization path of "coarse aggregate - medium and fine sand building materials - fine mud brick making": ≥0.5mm particles are directly sold as building aggregate or building sand; 0.075~0.1mm medium and fine sand is used for building materials after desliming; fine mud is mixed with cement and aggregate to make bricks after concentration and filtration. All particle sizes have corresponding resource utilization outlets, truly realizing the "complete utilization" and zero-emission disposal of tailings.

[0033] (5) The new process incorporates a complete environmental control chain—the mining stage uses wet operation to suppress dust, the concentration and filtration stage achieves mud-water separation, and the supernatant and filtration water are recycled into the return water pump pool, resulting in zero wastewater discharge. The brick-making stage uses natural curing, eliminating the need for sintering, thus avoiding secondary energy consumption and exhaust emissions, and blocking the risk of heavy metal migration and wastewater overflow from the source.

[0034] Overall, the new process developed in this invention is highly adaptable and can be implemented on a large scale. It is applicable to the comprehensive management of old tailings ponds and can also be used for source control in new mines, providing a replicable and scalable technical path for the safe disposal and green and low-carbon development of iron tailings. Attached Figure Description

[0035] Figure 1 This invention provides a new process flow diagram illustrating the principles and principles of collaborative tailings mining and comprehensive utilization in iron ore tailings ponds.

[0036] Figure 2 This is a structural layout diagram of the actual application of a new process for the coordinated mining and comprehensive utilization of tailings in an iron ore tailings pond according to the present invention.

[0037] The attached diagram is labeled as follows: 1-Excavator; 2-Crushing, slurry making, and slag separating machine; 3-Floating submersible slurry pump; 4-Transfer pump pool; 5-Tailings conveying pump; 6-Multi-stage screening and recycling integrated machine; 7-Magnetic separator; 8-Grading unit; 9-Thickener; 10-Filter press feed bin; 11-Filter press feed pump; 12-Filter press; 13-Return water pump pool; 14-Return water pump; 15-Sewage pump pool; 16-Sewage pump; 17-High-level water tank; 18-Environmentally friendly dual-shaft feeding crusher; 19-Brick making machine. Detailed Implementation

[0038] The following will describe in further detail, with reference to the accompanying drawings of the embodiments of the present invention, a novel process for the coordinated recovery and comprehensive utilization of tailings in an iron ore tailings dam. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0039] Depend on Figure 2 The diagram shown is a structural layout of a novel technology for the collaborative mining and comprehensive utilization of tailings in an iron ore tailings dam, as described in the present invention, in practical application. Figure 1 As can be seen, the new process for the co-mining and comprehensive utilization of tailings in iron ore tailings ponds of the present invention is implemented by the following steps:

[0040] S1, Recovery-Clean-up Pulping

[0041] The process combines dry and wet mining. An excavator 1 is used to mine the tailings in the iron ore tailings pond. A self-developed crushing, slurry making, and slag separating machine 2 is used to separate impurities from the water-bearing tailings. The tailings after impurity removal are then pumped to a transfer pump pool 4 by a float-type submersible slurry pump 3. The self-developed crushing, slurry making, and slag separating machine 2 uses a high-manganese steel wear-resistant roller body equipped with a screen with a screen aperture of 8-12mm. The float-type submersible slurry pump 3 uses a corrosion-resistant polyurethane impeller, and the float is made of high-density polyethylene.

[0042] S2, Screening-Magnetic Separation Recovery

[0043] The tailings slurry in the transfer pump pool 4 is fed into the screening operation via the tailings conveying pump 5. The screening operation adopts a multi-stage screening and recovery integrated machine 6, with three screening stages and screen mesh sizes of 5mm, 2mm, and 0.5mm respectively. The screening operation obtains ≥5mm coarse tailings, 2-5mm medium tailings sand, and 0.5-2mm fine tailings sand. The ≥5mm coarse tailings, 2-5mm medium tailings sand, and 0.5-2mm fine tailings sand are directly used as building aggregate. The product is sold as construction sand, and fine tailings with a particle size <0.5mm are discharged. The fine tailings with a particle size <0.5mm are fed into a magnetic separator 7 for magnetic separation to obtain iron concentrate powder with a TFe content of not less than 60.0%, and the new tailings from the magnetic separation are discharged. The wastewater generated by the magnetic separation is pumped into the sewage pump pool 15 by the sewage pump 16. The magnetic separator 7 is a wet permanent magnet drum magnetic separator. The tailings conveying pump 5 is a wear-resistant centrifugal pump with a conveying flow rate of 1.5 to 2.0 m / s.

[0044] S3, Combination Grading

[0045] The new tailings discharged from the magnetic separation in step S2 are fed into classifier unit 8. Classifier unit 8 adopts a series arrangement of "single spiral classifier + high frequency fine screen + hydrocyclone group". The underflow of the single spiral classifier is fed into the high frequency fine screen. The product on the high frequency fine screen is coarse sand with a particle size ≥0.1mm. The underflow is fed into the hydrocyclone group. The hydrocyclone group separates medium and fine sand with a particle size of 0.075~0.1mm. The mud content of the medium and fine sand is controlled within 3%. The separated coarse sand and medium and fine sand are dewatered by vibration and transported to the sand yard storage area. The overflow products of the single spiral classifier and the hydrocyclone are combined into fine slurry. The single-spiral classifier has a spiral diameter of 1500mm, a spiral speed of 18r / min, and an overflow concentration controlled at 15-20%. The hydrocyclone group consists of 3-5 hydrocyclones connected in parallel, with a diameter of 500mm for each hydrocyclone and a feed pressure of 0.3MPa. The high-frequency fine screen has a mesh size of 120, a vibration frequency of 2000-2500r / min, and an amplitude of 3-5mm.

[0046] S4, Concentration-Pressure Filtration

[0047] The fine slurry discharged from step S3 is fed into thickener 9. Flocculant is added to thickener 9 for sedimentation. The supernatant enters the return water pump pool 13 for recycling and is then transported to the high-level water tank 17 for continued use in water recovery. The slurry thickened by thickener 9 is transported to the filter press feed hopper 10 via filter press feed pump 11. It is then pressed into fine mud cakes by filter press 12, and excess water is separated. The cakes are then temporarily stored at the brick-making site. The water produced during filtration enters the return water pump pool 13 and is then transported to the high-level water tank 17 via return water pump 14 for continued use in water recovery. Thickener 9 is a high-efficiency deep cone thickener with a diameter of 12m and a cone angle of 60-70°. It has multiple inclined plates with an angle of 45°. The flocculant added to thickener 9 is anionic polyacrylamide with a molecular weight of 1000. The dosage is 10-20 g / t, calculated based on the weight of the dry fine slurry being processed. The addition method is to add it in stages: first add 70% of the flocculant at the feed inlet of the thickener, and then add the remaining 30% in the middle of the thickener to ensure uniform flocculation effect.

[0048] The filter press feed pump 11 is a wear-resistant slurry pump with a rated flow rate of 60 m³ / h and a head of 30 m. The pump shaft uses a silicon carbide mechanical seal, providing excellent sealing performance. The return water pump 13 is a pipeline pump with a rated flow rate of 50 m³ / h and a head of 100 m, enabling the recycling of recovered water and reducing water consumption. The filter press 12 is a horizontal quick-opening type equipped with a fully automatic control system and mechanical scraper cake discharge. The filter press 12 has a filtration area of ​​150 m², a filter plate size of 1250 × 1250 mm, and uses polyester fiber filter cloth. The filtration accuracy is 1–5 μm, the filtration pressure is controlled at 0.8–1.2 MPa, and the filtration time is 20–30 min. It is equipped with a fully automatic control system, which uses a PLC to automate the feeding, filtration, and cake discharge operations. Cake discharge is achieved using a mechanical scraper. The water generated during filtration is collected in a collection tank, then passes through a sedimentation tank to remove suspended impurities before entering the return water pump pool 13.

[0049] The return water pump pool 13 is equipped with a filtration device with a filtration accuracy of 80μm, which can remove fine impurities in the supernatant and control the suspended solids content of the recycled water to within 50mg / L, meeting the wet water use standard.

[0050] S5, Fine clay cake crushing and mixing - brick making

[0051] The fine clay cake obtained in step S4 is crushed by an environmentally friendly twin-shaft feeder crusher 18, and then mixed evenly with cement and aggregate before being fed into a brick-making machine 19 for pressing, extrusion, and production of wet brick blanks. These blanks are then placed on a fixed platform and naturally cured to produce brick products. The mass percentages of fine clay cake, aggregate, and cement are: fine clay cake 65%–77%, aggregate 10%–15%, and cement 13%–20%. The environmentally friendly dual-shaft feeding crusher 18 has a rotor speed of 400 r / min. The crushing chamber uses wear-resistant liners with a thickness of not less than 15 mm. The particle size of the crushed fine mud cake is controlled between 0.1 and 5 mm, with no obvious agglomeration. The aggregate is iron ore tailings feedstock with a particle size of 0.5 to 10 mm, a mud content of no more than 2%, a crushing value of no more than 25%, and a moisture content of ≤5% after drying. The cement used is 32.5 grade ordinary Portland cement. The brick making machine 19 is a fully automatic hydraulic type with a pressing pressure of 15 to 20 MPa and a forming speed of 10 to 15 pieces / min. The mold is made of wear-resistant cast iron, and the finished brick specifications are 240 mm × 115 mm × 53 mm standard bricks and 240 mm × 115 mm × 90 mm perforated brick molds. The fixed platform is made of concrete and is surrounded by a guardrail ≥1.2 m high. The spacing between green bricks is 5 to 10 mm. The temporary storage area of ​​the brick-making site is covered with a rainproof canopy, and the ground is laid with an impermeable membrane with a thickness of not less than 0.5mm to prevent the fine clay cake from getting damp and clumping. The temporary storage time shall not exceed 72 hours.

[0052] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A novel process for the co-extraction and comprehensive utilization of tailings in iron ore tailings ponds, characterized in that... The following steps are to be taken: S1, Recovery-Clean-up Pulping The process of combining "dry mining + wet mining" is adopted. The excavator (1) is used to mine the tailings in the iron ore tailings pond, and the impurities in the water-containing tailings are separated by the crushing, slurry making and slag separating machine (2). The tailings after impurity removal are then pumped to the transfer pump pool (4) by the float-type submersible slurry pump (3). S2, Screening-Magnetic Separation Recovery The tailings slurry in the transfer pump pool (4) is fed into the screening operation by the tailings conveying pump (5). The screening operation adopts a multi-stage screening and recycling integrated machine (6), with three screening grades and screen mesh sizes of 5mm, 2mm, and 0.5mm respectively. The screening operation obtains ≥5mm coarse tailings, 2-5mm medium tailings sand, and 0.5-2mm fine tailings sand. The ≥5mm coarse tailings, 2-5mm medium tailings sand, and 0.5-2mm fine tailings sand are directly sold as building aggregates or building sand products, and the fine tailings sand with a particle size <0.5mm is discharged. The <0.5mm fine tailings sand is fed into the magnetic separator (7) for magnetic separation to obtain iron concentrate powder with TFe of not less than 60.0%, and the new tailings from magnetic separation are discharged. The wastewater generated by magnetic separation is pumped into the sewage pump pool (15) by the sewage pump (16). S3, Combination Grading The new tailings discharged from the magnetic separation in step S2 are fed into the classifier unit (8). The classifier unit (8) is arranged in series with "single spiral classifier + high frequency fine screen + hydrocyclone group". The sand from the single spiral classifier is fed into the high frequency fine screen. The product on the high frequency fine screen is coarse sand with a particle size ≥ 0.1 mm. The product under the screen is fed into the hydrocyclone group. The hydrocyclone group separates medium and fine sand with a particle size of 0.075 to 0.1 mm. The mud content of the medium and fine sand is controlled within 3%. The separated coarse sand and medium and fine sand are transported to the sand yard storage area after being dewatered by vibration. The overflow products of the single spiral classifier and the hydrocyclone are combined into fine mud. The hydrocyclone group is composed of 3 to 5 hydrocyclones connected in parallel. The vibration frequency of the high frequency fine screen is 2000 to 2500 r / min and the amplitude is 3 to 5 mm. S4, Concentration-Pressure Filtration The fine mud discharged from step S3 is fed into the thickener (9). Flocculant is added to the thickener (9) for sedimentation. The supernatant enters the return water pump pool (13) for recycling and is transported to the high-level water pool (17) for continued use in the mining. The mud concentrated by the thickener (9) is transported to the filter press feed hopper (10) by the filter press feed pump (11). It is pressed into fine mud cakes by the filter press (12) and excess water is separated. It is then transferred to the brick-making site for temporary storage. The water produced by the filter press enters the return water pump pool (13) and is then transported to the high-level water pool (17) by the return water pump (14) for continued use in the mining. S5, Fine clay cake crushing and mixing - brick making The fine mud cake obtained in step S4 is crushed by an environmentally friendly twin-shaft feeder (18), and then mixed with cement and aggregates. After being fed into a brick making machine (19) for pressing and extrusion, wet brick blanks are placed on a fixed platform and naturally cured to produce brick products.

2. A novel process for the co-mining and comprehensive utilization of tailings in an iron ore tailings dam as described in claim 1, characterized in that: In step S5, the mass percentages of fine clay cake, aggregate, and cement are: fine clay cake 65%–77%, aggregate 10%–15%, and cement 13%–20%.

3. A novel process for the co-mining and comprehensive utilization of tailings in an iron ore tailings dam as described in claim 1, characterized in that: In step S1, the crushing, pulping and slag separating machine (2) uses a high manganese steel wear-resistant roller body equipped with a screen, and the screen aperture is selected as 8-12mm.

4. A novel process for the co-mining and comprehensive utilization of tailings in an iron ore tailings dam as described in claim 1, characterized in that: In step S1, the float-type submersible slurry pump (3) uses a corrosion-resistant polyurethane impeller and the float is made of high-density polyethylene.

5. A novel process for the co-mining and comprehensive utilization of tailings in an iron ore tailings dam as described in claim 1, characterized in that: In step S2, the magnetic separator (7) is a wet permanent magnet drum separator; the tailings conveying pump (5) is a wear-resistant centrifugal pump with a conveying flow rate of 1.5 to 2.0 m / s.

6. A novel process for the co-mining and comprehensive utilization of tailings in an iron ore tailings dam as described in claim 1, characterized in that: In step S4, the thickener (9) is a high-efficiency deep cone thickener with a cone angle of 60-70° and multiple inclined plates inside.

7. A novel process for the co-mining and comprehensive utilization of tailings in an iron ore tailings dam as described in claim 1, characterized in that: In step S4, the flocculant added to the thickener (9) is anionic polyacrylamide with a molecular weight of 8 million to 12 million and an addition amount of 10 to 20 g / t, calculated based on the weight of the dry fine slurry being processed.

8. A novel process for the co-mining and comprehensive utilization of tailings in an iron ore tailings dam as described in claim 1, characterized in that: In step S4, the filter press feed pump (11) is a wear-resistant slurry pump, the return water pump (13) is a pipeline pump, and the filter press (12) is a horizontal quick-opening type equipped with a fully automatic control system and mechanical scraper for cake discharge.

9. A novel process for the co-mining and comprehensive utilization of tailings in an iron ore tailings dam as described in claim 1, characterized in that: In step S5, the rotor speed of the environmentally friendly dual-shaft feeding crusher (18) is 300-400 r / min; the aggregate is iron ore tailings feed with a particle size of 0.5-10 mm and a moisture content of ≤5% after drying; and the cement is 32.5 grade ordinary Portland cement.

10. A novel process for the co-mining and comprehensive utilization of tailings in an iron ore tailings dam as described in claim 1, characterized in that: In step S5, the brick making machine (19) is a fully automatic hydraulic type. The mold is flexibly adjusted according to market demand. The fixed platform is made of concrete. The fixed platform is surrounded by a guardrail ≥1.2m high. The spacing between the green bricks is 5~10mm.

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