A blast furnace high-zinc ash zinc-iron-carbon wet grading resource recycling system

Abstract

The application provides a blast furnace high-zinc ash zinc-iron-carbon wet grading resource recycling system. It belongs to the technical field of metallurgical solid waste resource utilization, and comprises a raw material storage unit, a wet slurry preparation unit, a pretreatment screening unit, a spiral flow tank separation unit, a magnetic separation unit, a zinc-containing fine material enrichment and recovery unit, a solid-liquid separation unit and a finished product storage unit. The raw material storage unit quantitatively discharges to the wet slurry preparation unit to prepare uniform ore slurry, and after impurity removal by pretreatment screening, the ore slurry is sent to the spiral flow tank separation unit, and iron-carbon mixed materials and zinc-containing slurry are output according to the difference in density and particle size; the iron-carbon materials are separated by the magnetic separation unit to obtain iron powder and carbon powder, the zinc-containing slurry is separated by the sedimentation tank in the zinc-containing fine material enrichment and recovery unit, the overflow enters the zinc enrichment and concentration device, and finally the zinc component is enriched and recovered; the tail water and tail slurry of each unit are collected into the solid-liquid separation unit, and after pressure filtration, the clear water is returned to the slurry preparation unit for recycling, so that the iron, carbon and zinc components are separated and recycled in a closed loop.

Description

Technical Field

[0001] This invention relates to the field of metallurgical solid waste resource utilization technology, and in particular to a wet graded resource recovery system for blast furnace high-zinc ash, zinc, iron and carbon. Background Technology

[0002] The large amounts of dust and gas ash generated during blast furnace ironmaking are typical metallurgical solid wastes containing zinc, iron, and carbon. The zinc in the blast furnace mainly originates from zinc compounds carried in the ore and fuel. Under high-temperature reducing conditions, zinc is reduced to metallic zinc vapor and rises with the gas. During this ascent, it is oxidized to zinc oxide and accumulates in the dust. With the expansion of blast furnace production scale and the increase in zinc content in raw materials, the zinc content in blast furnace ash has shown a year-on-year upward trend, with some blast furnace ash containing more than 5% zinc, and even exceeding 10%. If high-zinc-content dust is directly returned to sintering or recycled within the blast furnace system, zinc will continuously accumulate within the furnace, leading to blast furnace lining nodules, decreased permeability, and fluctuating furnace conditions. In severe cases, it can even cause blast furnace shutdown and major overhaul, resulting in huge economic losses for steel companies.

[0003] From a resource recycling perspective, blast furnace ash contains three valuable components: iron, carbon, and zinc, giving it extremely high comprehensive recycling value. If these three components can be efficiently separated and recovered individually, not only can the harmful effects of zinc on blast furnace production be eliminated, but also three economically viable products—iron concentrate, carbon powder, and zinc products—can be obtained.

[0004] However, existing blast furnace ash treatment technologies have many shortcomings. First, traditional processes mostly employ single separation methods, such as relying solely on magnetic separation to recover iron or solely on gravity separation to recover carbon, failing to achieve simultaneous separation of the three components: iron, carbon, and zinc. Second, existing processes are mostly intermittent operations, lacking effective coordination and linkage between stages, resulting in low production efficiency and an inability to adapt to the continuous industrial production rhythm of blast furnace ash production. Third, zinc components are often ignored or removed only as impurities in existing processes, lacking a dedicated zinc recovery stage, leading to significant zinc resource loss, while the stockpiling of zinc-containing tailings poses a risk of secondary environmental pollution. Fourth, existing processes generally suffer from large wastewater discharge and high water consumption; if the fine-particle minerals and heavy metal ions in the tailings are discharged directly without proper treatment, they will cause serious pollution to surrounding water bodies.

[0005] Furthermore, while some patent documents have disclosed comprehensive recovery methods for blast furnace ash, most employ single separation techniques, such as magnetic separation for iron recovery or gravity separation for carbon recovery, failing to achieve simultaneous separation and separate recovery of the three valuable components: iron, carbon, and zinc. Although some documents mention zinc recovery, these are mostly theoretical descriptions lacking practical equipment configurations and process flow schemes.

[0006] In summary, existing technologies have not yet provided a complete system solution that can simultaneously achieve efficient separation and recovery of iron, carbon, and zinc components in high-zinc blast furnace ash, while meeting the requirements of continuous production and environmental protection. Summary of the Invention

[0007] To address the aforementioned technical problems, a wet-process graded resource recovery system for high-zinc ash, zinc, iron, and carbon from blast furnaces is provided. The technical means employed in this invention are as follows: A wet-process graded resource recovery system for high-zinc ash, zinc, iron, and carbon from blast furnaces. It includes a raw material storage unit, a wet slurry preparation unit, a pretreatment screening unit, a spiral flow separation unit, a magnetic separation unit, a zinc-containing fine material enrichment and recovery unit, a solid-liquid separation unit, and a finished product storage unit. The discharge port of the raw material storage unit is connected to the inlet of the wet slurry preparation unit. The slurry discharge port of the wet slurry preparation unit is connected to the inlet of the pretreatment screening unit via a slurry pump and pipeline. The undersize discharge port of the pretreatment screening unit is connected to the inlet of the spiral trough separation unit. The heavy material discharge port of the spiral trough separation unit is connected to the inlet of the magnetic separation unit. The light material discharge port of the spiral trough separation unit is connected to the inlet of the zinc-containing fine material enrichment and recovery unit. The iron concentrate outlet and carbon powder outlet of the magnetic separation unit and the zinc concentrate outlet of the zinc fine material enrichment and recovery unit are all connected to the corresponding finished product storage unit. The water inlet of the wet slurry preparation unit is connected to the clean water outlet of the solid-liquid separation unit through a return water pipeline. The tail slurry outlet of the zinc-containing fine material enrichment and recovery unit, the tail slurry outlet of the magnetic separation and fine separation unit, and the tail water outlet of the spiral flow trough separation unit are respectively connected to the feed inlet of the solid-liquid separation unit through pipelines.

[0008] Furthermore, the raw material storage unit includes a storage silo, a quantitative feeder, and a silo wall vibrator; the bottom outlet of the storage silo is connected to the inlet of the quantitative feeder, which is a screw feeder or a belt feeder; the silo wall vibrator is installed on the outer wall of the storage silo to assist in material feeding and prevent material from arching and clogging.

[0009] Furthermore, the wet slurry preparation unit includes a slurry preparation tank, a stirring mechanism, a water supply pipe, and a concentration detection sensor. The slurry preparation tank is a circular steel tank. The stirring mechanism is located inside the slurry preparation tank and includes a stirring shaft, stirring blades, and a drive motor. The drive motor is installed on the top of the slurry preparation tank and connected to the stirring shaft via a reducer. The stirring blades are installed at the lower end of the stirring shaft and extend into the slurry preparation tank. The water supply pipe is located at the upper part of the slurry preparation tank and is equipped with an electrically controlled flow valve. The concentration detection sensor is located inside the slurry preparation tank and is used to detect the slurry concentration in real time and feed the concentration signal back to the control system. The control system controls the opening of the electrically controlled flow valve according to the concentration signal to adjust the water supply.

[0010] Furthermore, the pretreatment screening unit includes a wet vibrating screen, a spraying device, and an under-screen collection trough; the wet vibrating screen is a linear vibrating screen or a circular vibrating screen with a screen mesh size of 80 to 200 mesh; the spraying device is located above the screen surface of the wet vibrating screen and is used to spray water onto the screen surface to assist screening and rinse the material on the screen; the under-screen collection trough is located below the wet vibrating screen and is used to collect qualified fine mineral slurry that has passed through the screen; the outlet of the under-screen collection trough is connected to the inlet of the spiral flow channel separation unit through a slurry pump and pipeline; the outlet of the material on the screen of the wet vibrating screen is connected to an impurity collection device.

[0011] Furthermore, the spiral chute sorting unit adopts a continuous spiral gravity sorting device, including at least one set of spiral chutes. The spiral chutes are fixed or rotating structures with 4 to 6 spiral turns. The spiral chute sorting unit performs stratified sorting based on the density and particle size differences of iron, carbon, and zinc materials. The heavy material outlet outputs an iron-carbon mixture mainly composed of iron minerals and some carbon particles, while the light material outlet outputs a zinc-containing slurry mainly composed of fine zinc minerals and carbon.

[0012] Furthermore, the magnetic separation unit includes a first-stage magnetic separator and a second-stage magnetic separator, both of which are wet drum magnetic separators. The feed inlet of the first-stage magnetic separator is connected to the heavy material outlet of the spiral trough separation unit, and the magnetic material outlet of the first-stage magnetic separator is connected to the feed inlet of the second-stage magnetic separator. The non-magnetic material outlet of the first-stage magnetic separator outputs coarse carbon powder. The magnetic material outlet of the second-stage magnetic separator outputs finished iron concentrate, and the non-magnetic material outlet of the second-stage magnetic separator outputs middlings and returns them to the feed inlet of the first-stage magnetic separator for recycling. The magnetic field strength of both the first-stage and second-stage magnetic separators is 1000 Gauss to 4000 Gauss.

[0013] Furthermore, the zinc-containing fine material enrichment and recovery unit includes a sedimentation tank, a first filter press, and a zinc enrichment and concentration device connected in sequence. The inlet of the sedimentation tank is connected to the light material outlet of the spiral trough sorting unit, which is used to allow the zinc-containing slurry to settle naturally. The coarse underflow after sedimentation is discharged as tailings to the solid-liquid separation unit, and the zinc-containing fine particles after sedimentation overflow are transported to the zinc enrichment and concentration device. The zinc enrichment and concentration device is a multi-stage sedimentation and concentration tank or a membrane concentration device, which is used to enrich and concentrate the fine zinc-containing solid material in the overflow. The concentrated zinc concentrate is dewatered by the first filter press and then transported to the finished product storage unit. The concentrated overflow water is transported to the solid-liquid separation unit.

[0014] Furthermore, the solid-liquid separation unit includes a tailings collection tank and a second filter press; the tailwater and tailings generated by the pretreatment screening unit, the spiral flow channel separation unit, the magnetic separation unit, and the zinc-containing fine material enrichment and recovery unit, as well as the wastewater generated during the flushing or venting of each unit of the system, are uniformly collected into the tailings collection tank through pipelines, and after being stirred and homogenized, are pumped to the second filter press for solid-liquid separation; the second filter press is a plate and frame filter press or a chamber filter press, the filtrate outlet of the second filter press is connected to the water inlet of the wet slurry conditioning unit through a return water pipeline, and the filter cake outlet of the second filter press is connected to a residue collection device.

[0015] Furthermore, the finished product storage unit includes an iron concentrate storage bin, a carbon powder storage bin, and a zinc enrichment storage bin. The iron concentrate storage bin is connected to the iron concentrate outlet of the magnetic separation unit, the carbon powder storage bin is connected to the carbon powder outlet of the magnetic separation unit, and the zinc enrichment storage bin is connected to the zinc enrichment outlet of the zinc-containing fine material enrichment and recovery unit.

[0016] Furthermore, the system also includes a control system, which is electrically connected to the raw material storage unit, the wet slurry preparation unit, the pretreatment screening unit, the spiral flow channel separation unit, the magnetic separation unit, the zinc-containing fine material enrichment and recovery unit, and the solid-liquid separation unit, respectively, for controlling the operation and coordinated operation of each unit.

[0017] The present invention has the following advantages: 1. This invention achieves the simultaneous separation and separate recovery of zinc, iron, and carbon—three valuable components—from blast furnace high-zinc ash through an organic combination of three stages of progressive separation processes: spiral flow gravity separation, two-stage magnetic separation for fine separation, and wet enrichment through precipitation concentration. The gravity separation stage utilizes the significant density differences among iron, carbon, and zinc to perform preliminary coarse separation; the magnetic separation stage utilizes the unique magnetic properties of iron minerals to achieve fine separation of iron and carbon; and the wet enrichment stage utilizes the solubility and sedimentation characteristics of zinc to achieve the specific recovery of the zinc component. These three stages are sequentially connected and complementary, overcoming the inherent limitation of traditional single-stage separation methods that cannot simultaneously separate the three components, resulting in a significant improvement in both separation purity and resource utilization.

[0018] 2. In this invention, each unit is seamlessly connected in sequence through pipelines, slurry pumps and conveying equipment. After the raw materials enter the storage unit, they go through the stages of slurry preparation, screening, spiral separation, magnetic separation, zinc liquid enrichment and solid-liquid separation in sequence. Finally, three finished products, iron concentrate, carbon powder and zinc concentrate, are produced simultaneously. The whole process is continuous and there are no production interruptions. It abandons the traditional intermittent production mode, greatly improves production efficiency, and can adapt to the industrial production rhythm of continuous ash discharge from blast furnace.

[0019] 3. This invention pre-separates zinc-containing light materials from iron-containing heavy materials through spiral flow channel sorting, and then recovers the zinc component in the form of concentrate through a zinc fine material enrichment and recovery unit. This eliminates the problem of zinc recycling and enrichment caused by zinc returning to sintering or the blast furnace system with blast furnace ash from the source. It can effectively prevent equipment and process problems such as blast furnace nodules, furnace lining damage, and furnace condition fluctuations caused by zinc recycling and enrichment, and ensure the long-term stable operation of the blast furnace body.

[0020] 4. This invention collects and filters all tailwater and slurry generated in each stage of the system through a solid-liquid separation unit. The filtered water is then directly returned to the water inlet of the wet slurry preparation unit for recycling, forming a complete closed-loop circulation system for water supply, sorting, drainage, and return. The entire process involves no wastewater discharge, significantly reducing production water consumption and eliminating the environmental pollution risks associated with wastewater discharge, thus meeting the policy requirements for the resource utilization and harmless treatment of solid waste in the steel industry.

[0021] 5. All functional units of this invention use mature industrial equipment, the connection between units is reasonable and the logistics are smooth. The overall system structure is compact and the footprint is moderate. It can be deployed in existing steel plant areas and has good industrial applicability and promotion value. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a system diagram of the present invention.

[0024] Figure 2 This is a schematic diagram of the spiral flow channel sorting unit structure of the present invention.

[0025] In the diagram: 1. Frame; 2. Spiral sorting trough; 3. Central rotating shaft; 4. Feed and water distribution assembly; 5. Speed ​​control drive mechanism; 6. Heavy material outlet; 7. Light material outlet; 81. Circulating water tank; 82. Circulating water pump; 83. Water supply pipeline; 84. Return water pipeline; 85. Sedimentation and clarification device. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0027] like Figure 1 As shown in the figure, this invention discloses a wet-process graded resource recovery system for high-zinc ash, zinc, iron, and carbon materials in blast furnaces. The system mainly includes a raw material storage unit, a wet slurry preparation unit, a pretreatment screening unit, a spiral flow separator unit, a magnetic separation unit, a zinc-containing fine material enrichment and recovery unit, a solid-liquid separation unit, and a finished product storage unit. Each unit is connected sequentially according to the material flow direction, forming a complete wet-process graded resource recovery production line.

[0028] The raw material storage unit is located at the beginning of the system and is used to store the high-zinc ash raw material from the blast furnace to be processed. The raw material storage unit includes a storage bin, a quantitative feeder, and a bin wall vibrator.

[0029] The storage silo is used to store high-zinc ash raw materials from blast furnaces to be processed. The bottom outlet of the storage silo is connected to the inlet of the quantitative feeder. The quantitative feeder, either a screw feeder or a belt feeder, is installed at the bottom outlet of the storage silo and uses frequency conversion speed regulation to achieve quantitative output of the raw materials. The silo wall vibrator is installed on the lower part of the outer wall of the storage silo and is intermittently activated during feeding. High-frequency vibration breaks down the adhesion and arching of materials on the silo wall, preventing material arching and blockage, and ensuring smooth material flow.

[0030] The outlet of the raw material storage unit is connected to the inlet of the wet slurry preparation unit.

[0031] The wet slurry preparation unit is located downstream of the raw material storage unit and is used to thoroughly mix high-zinc ash raw materials with water to prepare a slurry with a certain concentration. The wet slurry preparation unit includes a slurry preparation tank, a stirring mechanism, a water supply pipe, and a concentration detection sensor.

[0032] The slurry preparation tank is a circular steel tank. The top of the tank is equipped with a feed inlet, a water supply pipe inlet, and a mounting base for the stirring drive motor, while the lower part of the side wall of the tank is equipped with a slurry outlet.

[0033] The stirring mechanism is disposed in the mixing tank, and includes a stirring shaft, stirring blades, and a drive motor. The drive motor is installed on the top of the mixing tank and connected to the stirring shaft through a reducer. The stirring blades are installed at the lower end of the stirring shaft and extend into the mixing tank to powerfully stir the material in the tank so that it is fully mixed with water.

[0034] The water supply pipe is located at the top of the slurry mixing tank and connects to the water supply port at the top of the tank. An electrically controlled flow valve is installed on the water supply pipe. A concentration detection sensor is located inside the slurry mixing tank to detect the slurry concentration in real time and feed the concentration signal back to the control system. The control system controls the opening of the electrically controlled flow valve based on the concentration signal to adjust the water supply amount, thereby stabilizing the slurry concentration within the target range.

[0035] The qualified slurry after slurry preparation is discharged through the slurry outlet at the bottom of the slurry preparation tank. The slurry outlet of the slurry preparation tank is connected to the feed inlet of the pretreatment screening unit through a slurry pump and a conveying pipeline.

[0036] The pretreatment screening unit is used to screen and classify the slurry after conditioning, removing coarse particles and agglomerated materials. The pretreatment screening unit includes a wet vibrating screen, a spraying device, and an under-screen collection trough.

[0037] The wet vibrating screen is a linear vibrating screen or a circular vibrating screen. The spraying device is set above the screen surface of the wet vibrating screen and includes multiple rows of spray pipes arranged along the length of the screen surface. The spray pipes are equipped with several atomizing nozzles for spraying water onto the screen surface to assist in screening and to rinse the material on the screen.

[0038] The undersize collection trough is located below the wet vibrating screen and is used to collect qualified fine mineral slurry that passes through the screen. The discharge port of the undersize collection trough is connected to the inlet of the spiral flow trough sorting unit via a slurry pump and pipeline. The oversize discharge port of the wet vibrating screen is connected to an impurity collection device. Coarse particles and agglomerated materials with a particle size larger than the screen mesh are retained on the screen surface and move towards the oversize outlet under the action of vibration and are discharged.

[0039] The undersize discharge port of the pretreatment screening unit is connected to the feed port of the spiral flow channel sorting unit.

[0040] The spiral flue sorting unit is used for gravity sorting based on the density differences of iron, carbon, and zinc materials. In this embodiment, as... Figure 2 As shown, the spiral flow channel sorting unit adopts a spiral flow channel type continuous iron-carbon sorting device, the specific structure of which is as follows: The device includes a frame 1, a spiral sorting trough 2, a central rotating shaft 3, a feeding and water distribution assembly 4, a speed regulating drive mechanism 5, a heavy material outlet 6, a light material outlet 7, and a water circulation assembly.

[0041] The frame 1 is a frame structure welded from structural steel, with an overall rectangular frame shape. Anchor bolt holes are provided at the bottom for fixing it to the workshop's concrete foundation. The top of the frame 1 has an upper platform, the bottom has a base platform, and multiple annular support beams are arranged vertically at intervals in the middle to provide auxiliary support and protection for the spiral sorting trough during operation. The overall height of the frame 1 is determined based on the number of spiral turns and the spiral diameter of the spiral sorting trough 2.

[0042] The central rotating shaft 3 is vertically positioned at the center of the frame 1. The bearing housing includes an upper bearing housing and a lower bearing housing. The upper bearing housing is fixedly installed at the center opening of the upper platform at the top of the frame 1, and the lower bearing housing is fixedly installed at the center opening of the base platform at the bottom of the frame 1. The upper end of the central rotating shaft 3 passes through the upper bearing housing and extends out a certain length, and the lower end of the central rotating shaft 3 passes through the lower bearing housing and extends out a certain length. The central rotating shaft 3 is rotatably mounted on the frame 1 via rolling bearings within the upper and lower bearing housings, allowing it to rotate freely.

[0043] The spiral sorting trough 2 has a spiral structure and is fixedly mounted on the outer wall of the central rotating shaft 3 by multiple radial connecting frames. One end of the radial connecting frame is welded or fixed to the outer wall of the central rotating shaft 3 via a flange, and the other end is welded or bolted to the back of the spiral sorting trough 2. Multiple radial connecting frames are spaced at different heights along the axial direction of the central rotating shaft 3. Each spiral trough is supported by at least 2 to 4 radial connecting frames, ensuring the spiral sorting trough 2 remains structurally stable and does not experience relative displacement or deformation during rotation. The spiral sorting trough 2 rotates synchronously with the central rotating shaft 3 and is located in the space between the upper and lower bearing seats. The spiral sorting trough 2 has 4 to 6 spiral turns, and the spiral diameter is determined according to the throughput, typically 1 to 2 meters. The cross-section of the spiral sorting trough 2 is arc-shaped. The spiral sorting trough 2 is made of wear-resistant materials, such as integral polyurethane casting, wear-resistant rubber vulcanization molding, or cast stone-lined steel plate welding, to extend the service life of the equipment and prevent wear and contamination of the sorted products. Preferably, the spiral sorting trough 2 adopts a trough width structure that gradually narrows along the material flow direction. The trough width is the maximum design value at the top inlet of the spiral sorting trough 2. As the number of spiral turns increases, the trough width gradually decreases at a predetermined narrowing slope. At the bottom outlet, the trough width narrows to the minimum design value. This narrowing slope matches the rate of increase of centrifugal force experienced by the slurry as it flows along the spiral channel.

[0044] The speed-regulating drive mechanism 5 includes an adjustable-speed motor, a reducer, a coupling, and a frequency converter. The reversing reducer is fixedly mounted on the base platform at the bottom of the frame, and contains a meshing driving bevel gear and a driven bevel gear. The driving bevel gear is mounted on the horizontal input shaft of the reversing reducer and is connected to the output shaft of the adjustable-speed motor via a flexible coupling; the driven bevel gear is mounted on the vertical output shaft of the reversing reducer, which is connected to the lower protruding end of the central rotating shaft 3 via a coupling. The adjustable-speed motor is horizontally mounted on the base platform, and its horizontal rotational motion is converted into vertical rotational motion after being reversed by the bevel gear pair inside the reversing reducer and output to the central rotating shaft 3. The frequency converter is fixedly installed on the outer wall of the frame 1 or inside the electrical control cabinet. The output end of the frequency converter is electrically connected to the power input end of the adjustable speed motor. The speed of the adjustable speed motor can be changed by adjusting the output frequency of the frequency converter. After passing through the reducer, the central rotating shaft 3 is driven to rotate at the set speed. The central rotating shaft 3 then drives the spiral sorting groove 2 fixed on its outer wall to rotate as a whole.

[0045] The feed and water distribution assembly 4 is located at the top inlet of the spiral sorting trough 2, and includes a water distribution plate and uniform flow distribution holes. The water distribution plate has a circular disc structure and is horizontally positioned directly above the top inlet of the spiral sorting trough 2. It is fixed to the upper platform of the frame 1 by a bracket, and a gap is left between the water distribution plate and the spiral sorting trough 2 to ensure that the water distribution plate does not rotate with the spiral sorting trough 2. The uniform flow distribution holes are multiple circular through holes, distributed on the entire surface of the water distribution plate in a concentric circle array with equal spacing or a rectangular array. After the slurry is transported to the top of the water distribution plate through the feed pipe, it is evenly spread on the surface of the water distribution plate and then distributed by the uniform flow distribution holes, entering the interior of the spiral sorting trough 2 with a uniform flow rate and volume.

[0046] In a preferred embodiment of this invention, a flow-guiding and buffering structure is further provided on the inner wall of the spiral sorting tank 2. The flow-guiding and buffering structure is an arc-shaped buffer baffle made of wear-resistant rubber or polyurethane material. Its curvature matches the curvature of the inner wall of the spiral sorting tank 2. The arc-shaped buffer baffle is fixed to the inner wall of the spiral sorting tank 2 by bolts or adhesive. The convex surface of the arc-shaped buffer baffle faces the direction of the slurry flow, and both ends extend laterally along the tank body. Multiple arc-shaped buffer baffles are spaced apart along the spiral direction of the spiral sorting tank 2. The distance between two adjacent arc-shaped buffer baffles is the arc length of half a turn to one turn of the spiral sorting tank 2. The height of the arc-shaped buffer baffle is 1 / 3 to 1 / 2 of the tank depth, and the arc length is 1 / 4 to 1 / 3 of the tank width.

[0047] The heavy material outlet 6 is located on the inner ring side at the lower end of the spiral sorting trough 2. It is a rectangular or circular opening with a width that matches the width of the inner ring side of the spiral sorting trough 2. A heavy material collection pipe is connected to the opening. The heavy material collection pipe extends downward at an angle to guide the iron mineral particles that have settled in the lower layer of the trough and tend to move towards the inner ring to the discharge device and enter the magnetic separation unit for subsequent sorting.

[0048] The light material outlet 7 is located on the outer ring side of the lower end of the spiral sorting trough 2. It is a rectangular or circular opening with a width that matches the width of the outer ring side of the spiral sorting trough 2. A light material collection pipe is connected to the opening. The light material collection pipe extends downward at an angle to guide the carbon particles and zinc-containing fine particles that are suspended in the upper layer of the water flow and tend to move towards the outer ring to be discharged from the device.

[0049] The discharge port 6 for heavy materials is located on the inner ring side, while the discharge port 7 for light materials is located on the outer ring side. This is consistent with the movement pattern of iron mineral particles tending towards the inner ring and carbon particles tending towards the outer ring during the sorting process, which can maximize the sorting accuracy.

[0050] The water circulation assembly includes a circulating water tank 81, a circulating water pump 82, a water supply pipeline 83, a return water pipeline 84, and a sedimentation and clarification device 85. The circulating water tank 81 is located on one side of the frame 1 and is used to store and separate the water. The circulating water pump 82 is fixedly installed near the circulating water tank 81. The suction port of the circulating water pump 82 is connected to the bottom outlet of the circulating water tank 81 via the suction pipeline. The outlet of the circulating water pump 82 is connected to the water distribution plate of the feed distribution assembly 4 via the water supply pipeline 83. The water supply pipeline 83 is equipped with a flow regulating valve and a pressure gauge. The sedimentation and clarification device 85 is an inclined plate sedimentation tank or a thickener, used to further clarify the fine-particle sludge in the return water. The clarified water after sedimentation and clarification flows by gravity or is pumped back to the circulating water tank 81 for recycling. The circulating water tank 81 is also equipped with a water replenishment interface to replenish the water lost by the product.

[0051] The complete circulation path is as follows: the clean water in the circulating water tank 81 is pressurized by the circulating water pump 82 and transported to the feed water distribution component 4 through the water supply pipeline 83. After mixing with the slurry, it enters the spiral separator 2 to participate in the separation operation. After the separation is completed, the water is discharged from the two discharge ports along with the iron concentrate and carbon concentrate and enters their respective sedimentation tanks for preliminary solid-liquid separation. The overflow clean water from the sedimentation tank enters the sedimentation clarification device 85 for deep clarification. The clarified clean water is returned to the circulating water tank 81 to complete a complete circulation cycle.

[0052] The heavy material outlet of the spiral flue sorting unit is connected to the feed inlet of the magnetic separation unit, and the light material outlet of the spiral flue sorting unit is connected to the feed inlet of the zinc-containing fine material enrichment and recovery unit.

[0053] The magnetic separation unit is used to magnetically separate the iron-carbon mixture output from the spiral flow separator to obtain iron concentrate and carbon powder. The magnetic separation unit includes a primary magnetic separator and a secondary magnetic separator, both of which are wet drum magnetic separators.

[0054] The inlet of the first-stage magnetic separator is connected to the heavy material outlet of the spiral trough separation unit. The magnetic material outlet of the first-stage magnetic separator is connected to the inlet of the second-stage magnetic separator. The non-magnetic material outlet of the first-stage magnetic separator outputs coarse carbon powder and sends it to the finished product storage unit. The magnetic material outlet of the second-stage magnetic separator outputs finished iron concentrate and sends it to the finished product storage unit. The non-magnetic material outlet of the second-stage magnetic separator outputs middlings and connects to the inlet of the first-stage magnetic separator through a middlings return pipeline to achieve cyclic separation. The magnetic field strength of both the first-stage and second-stage magnetic separators is 1000 Gauss to 4000 Gauss.

[0055] The zinc-containing fine material enrichment and recovery unit is used to enrich and recover the zinc-containing slurry output from the spiral flow trough sorting unit to obtain zinc-enriched material. The zinc-containing fine material enrichment and recovery unit includes a sedimentation tank, a first filter press, and a zinc enrichment and concentration device connected in sequence.

[0056] The sedimentation tank is a reinforced concrete or steel structure. Its inlet connects to the light material outlet of the spiral trough sorting unit, and is used for natural sedimentation of the zinc-containing slurry. The bottom of the sedimentation tank has a conical structure to facilitate the collection and discharge of underflow sediments. The coarse underflow after sedimentation is discharged as tailings to the solid-liquid separation unit. An overflow outlet is provided at the top of the sedimentation tank, through which the settled zinc-containing fine particles overflow are transported to the zinc enrichment and concentration device.

[0057] The zinc enrichment and concentration device is a multi-stage sedimentation and concentration tank or a membrane concentration device, used to enrich and concentrate zinc ions in the clarified liquid. The overflow port of each inclined plate sedimentation and concentration tank is connected to the feed port of the next stage, and the overflow port of the third stage is connected to the solid-liquid separation unit through a pipeline. The underflow of the concentrated zinc concentrate is dewatered by pressure filtration and then transported to the finished product storage unit.

[0058] The solid-liquid separation unit is used to separate the tailwater and tail slurry generated by each unit of the system into solid and liquid components, thereby realizing the recycling of water resources. The solid-liquid separation unit includes a tail slurry collection tank and a second filter press.

[0059] The tailings collection tank, constructed of steel or concrete, is used to collect tailwater and tailings generated by each unit of the system. Tailings and tailings from the pretreatment screening unit, the spiral flow trough sorting unit, the magnetic separation unit, and the zinc-containing fine material enrichment and recovery unit, as well as wastewater generated during flushing or venting of each unit, are all collected in the tailings collection tank via pipelines. The tailings collection tank is equipped with a stirring device to prevent solid particles from settling and caking.

[0060] The outlet of the tailings collection tank is connected to the inlet of the second filter press via a slurry pump and pipeline. The second filter press is a plate and frame filter press or a chamber filter press. The filtrate outlet of the second filter press is connected to the water inlet of the wet slurry conditioning unit via a return water pipeline, which is equipped with a return water pump and a flow meter. The filter cake outlet of the second filter press is connected to a residue collection device via a belt conveyor or a screw conveyor.

[0061] The finished product storage unit includes an iron concentrate storage bin, a carbon powder storage bin, and a zinc enrichment storage bin. The iron concentrate storage bin is connected to the iron concentrate outlet of the magnetic separation unit and is located below the magnetic material outlet of the second-stage magnetic separator. The carbon powder storage bin is connected to the carbon powder outlet of the magnetic separation unit and is located below the non-magnetic material outlet of the first-stage magnetic separator. The zinc enrichment storage bin is connected to the zinc enrichment outlet of the zinc-containing fine material enrichment and recovery unit and is located below the filter press outlet of the zinc-containing fine material enrichment and recovery unit.

[0062] In a preferred embodiment of the present invention, the system further includes a control system. The control system employs a programmable logic controller (PLC) as the core control unit, and is electrically connected via industrial Ethernet or fieldbus to the frequency converters, electric valves, sensors, and actuators of the raw material storage unit, the wet slurry preparation unit, the pretreatment screening unit, the spiral flow separator, the magnetic separation unit, the zinc-containing fine material enrichment and recovery unit, and the solid-liquid separation unit, respectively. This control system controls the start-up and shutdown of each device, speed regulation, valve opening regulation, and the monitoring and recording of process parameters, thereby achieving coordinated operation and linkage of each unit and automated operation of the entire system. All electrical control components and control logic involved in the above control system are mature existing technologies in the field, and the present invention does not modify their hardware structure or control program itself.

[0063] The workflow of this system is as follows: The high-zinc ash raw material for blast furnace is transported by vehicles or pneumatic conveying systems into the storage bins of the raw material storage unit. During production, the bin wall vibrator is intermittently activated to assist in feeding, and the quantitative feeder continuously and evenly conveys the raw material to the slurry tank of the wet slurry preparation unit according to the set feeding amount.

[0064] After the raw materials enter the mixing tank, they are thoroughly mixed with water under the strong stirring action of the agitator. A concentration sensor monitors the slurry concentration in real time and feeds the signal back to the control system. The control system compares the measured concentration with a preset target concentration value and controls the water replenishment by adjusting the opening of the electrically controlled flow valve, thus stabilizing the slurry concentration within the target range. The qualified slurry, after mixing, is discharged through the outlet at the bottom of the mixing tank and pumped to the pretreatment screening unit by a slurry pump.

[0065] After the slurry enters the screen surface of the wet vibrating screen, it undergoes screening and classification under the combined action of vibration and spray water. Qualified fine particles smaller than the screen mesh size pass through the screen and fall into the undersize collection trough, where they are pumped by the slurry pump to the spiral flow trough separation unit. Coarse particles and agglomerated materials larger than the screen mesh size remain on the screen surface and move towards the oversize outlet under vibration, then are discharged and enter the impurity collection box for periodic cleaning.

[0066] Qualified fine mineral slurry is conveyed through the feed pipe to the water distribution plate of the feed distribution assembly 4. After being evenly distributed on the water distribution plate, the slurry is distributed through various uniform diversion holes and spread evenly into the interior of the spiral separator 2 at a uniform flow rate. After entering the spiral separator 2, the slurry slowly flows downward along the spiral channel as the spiral separator 2 rotates. During the flow, the particle group in the slurry first stratifies vertically. The denser iron mineral particles gradually settle to the bottom of the material layer under the action of gravity, while the less dense carbon particles and zinc-containing fine particles are suspended in the upper part of the material layer. Subsequently, under the action of centrifugal force generated by the spiral motion, the stratified materials further undergo lateral banding: the iron mineral particles settled at the bottom of the tank tend to move towards the inner circle, while the carbon particles and zinc-containing fine particles suspended in the upper layer of the water flow are thrown towards the outer circle. During this process, the arc-shaped buffer baffle continuously buffers and rectifyes the high-speed flowing slurry, suppresses turbulence and mixing, and ensures the stability of the formed stratification and banding pattern. Ultimately, the iron ore particles that tend to move in the inner circle are discharged from the heavy material outlet 6 located on the inner side of the lower end of the spiral sorting tank 2, forming an iron-carbon mixture mainly composed of iron ore and mixed with some carbon particles; the carbon particles and zinc-containing fine particles that tend to move in the outer circle are discharged from the light material outlet 7 located on the outer side of the lower end of the spiral sorting tank 2, forming a zinc-containing slurry. Operators can adjust the rotational speed of the spiral sorting tank 2 by changing the output frequency of the frequency converter according to the current slurry concentration, material particle size, and throughput, thereby ensuring the device always operates at its optimal sorting state.

[0067] The iron-carbon mixture first enters a primary magnetic separator. Iron ore particles are adsorbed onto the surface of the magnetic rollers and discharged from the magnetic discharge port. Carbon particles and other non-magnetic materials are discharged from the non-magnetic discharge port as coarse carbon powder and sent to the carbon powder storage silo. The magnetic product from the primary magnetic separator enters a secondary magnetic separator for further refining, separating out a small amount of mixed non-magnetic materials. The middlings are returned to the primary magnetic separator via a return pipeline for re-sorting. The secondary magnetic separator outputs finished iron concentrate from its magnetic discharge port and is sent to the iron concentrate storage silo.

[0068] The zinc-containing slurry first enters a sedimentation tank for natural settling. The coarse underflow after settling is discharged as tailings to the solid-liquid separation unit. The supernatant (containing dissolved zinc ions and fine zinc minerals) from the sedimentation tank overflows into a zinc enrichment and concentration unit. In a multi-stage series inclined plate sedimentation and concentration tank, the zinc component is further enriched and concentrated. The concentrated zinc concentrate underflow is then dewatered by a first filter press to obtain the finished zinc concentrate, which is then sent to a zinc concentrate storage silo.

[0069] All tailwater and tail slurry generated by each unit in the system are collected in a tail slurry collection tank via pipelines. The material in the collection tank is kept in a uniform suspended state by a stirring device and then pumped by a slurry pump to the second filter press for solid-liquid separation. The filter press, operating at a filtration pressure of 0.6 MPa to 1.2 MPa, traps solid particles from the tail slurry on the filter cloth surface to form a filter cake. The filter cake is then sent to a residue collection bin for centralized transportation. The filtrate (clean water) from the filter press is pressurized by a return water pump and transported through a return water pipeline to the water inlet of the wet slurry preparation unit, achieving closed-loop recycling of the selected water.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wet-process graded resource recovery system for high-zinc ash, zinc, iron, and carbon from blast furnaces, characterized in that, It includes a raw material storage unit, a wet slurry preparation unit, a pretreatment screening unit, a spiral flow separation unit, a magnetic separation unit, a zinc-containing fine material enrichment and recovery unit, a solid-liquid separation unit, and a finished product storage unit. The discharge port of the raw material storage unit is connected to the inlet of the wet slurry preparation unit. The slurry discharge port of the wet slurry preparation unit is connected to the inlet of the pretreatment screening unit via a slurry pump and pipeline. The discharge port of the undersize material of the pretreatment screening unit is connected to the inlet of the spiral trough separation unit. The discharge port of the heavy material of the spiral trough separation unit is connected to the inlet of the magnetic separation unit. The discharge port of the light material of the spiral trough separation unit is connected to the inlet of the zinc-containing fine material enrichment and recovery unit. The iron concentrate outlet and carbon powder outlet of the magnetic separation unit and the zinc concentrate outlet of the zinc-containing fine material enrichment and recovery unit are all connected to the corresponding finished product storage unit. The water inlet of the wet slurry preparation unit is connected to the clean water outlet of the solid-liquid separation unit through a return water pipeline. The tail slurry outlet of the zinc-containing fine material enrichment and recovery unit, the tail slurry outlet of the magnetic separation and fine separation unit, and the tail water outlet of the spiral flow trough separation unit are respectively connected to the feed inlet of the solid-liquid separation unit through pipelines.

2. The wet-process graded resource recovery system for high-zinc ash, zinc, iron, and carbon from a blast furnace according to claim 1, characterized in that, The raw material storage unit includes a storage bin, a quantitative feeder, and a bin wall vibrator. The bottom outlet of the storage bin is connected to the inlet of the quantitative feeder, which is a screw feeder or a belt feeder. The bin wall vibrator is installed on the outer wall of the storage bin to assist in material feeding and prevent material from arching and clogging.

3. The wet-process graded resource recovery system for high-zinc ash, zinc, iron, and carbon in blast furnaces according to claim 1, characterized in that, The wet slurry preparation unit includes a slurry preparation tank, a stirring mechanism, a water supply pipe, and a concentration detection sensor. The slurry preparation tank is a circular steel tank. The stirring mechanism is located inside the slurry preparation tank and includes a stirring shaft, stirring blades, and a drive motor. The drive motor is installed on the top of the slurry preparation tank and connected to the stirring shaft through a reducer. The stirring blades are installed at the lower end of the stirring shaft and extend into the slurry preparation tank. The water supply pipe is located at the upper part of the slurry preparation tank and is equipped with an electrically controlled flow valve. The concentration detection sensor is located inside the slurry preparation tank and is used to detect the slurry concentration in real time and feed the concentration signal back to the control system. The control system controls the opening of the electrically controlled flow valve according to the concentration signal to adjust the water supply.

4. The wet-process graded resource recovery system for high-zinc ash, zinc, iron, and carbon from a blast furnace according to claim 1, characterized in that, The pretreatment screening unit includes a wet vibrating screen, a spraying device, and an under-screen collection trough. The wet vibrating screen is a linear or circular vibrating screen with a screen mesh size of 80 to 200 mesh. The spraying device is located above the screen surface of the wet vibrating screen and is used to spray water onto the screen surface to assist screening and rinse the material on the screen. The under-screen collection trough is located below the wet vibrating screen and is used to collect qualified fine mineral slurry that has passed through the screen. The outlet of the under-screen collection trough is connected to the inlet of the spiral flow channel separation unit through a slurry pump and pipeline. The outlet of the material on the screen of the wet vibrating screen is connected to an impurity collection device.

5. The wet-process graded resource recovery system for high-zinc ash, zinc, iron, and carbon in blast furnaces according to claim 1, characterized in that, The spiral chute sorting unit adopts a continuous spiral gravity sorting device, including at least one set of spiral chutes. The spiral chutes are fixed or rotating structures with 4 to 6 spiral turns. The spiral chute sorting unit performs stratified sorting based on the density and particle size differences of iron, carbon, and zinc materials. The heavy material outlet outputs an iron-carbon mixture mainly composed of iron minerals and some carbon particles, while the light material outlet outputs a zinc-containing slurry mainly composed of fine zinc minerals and carbon.

6. The wet-process graded resource recovery system for high-zinc ash, zinc, iron, and carbon in blast furnaces according to claim 1, characterized in that, The magnetic separation unit includes a first-stage magnetic separator and a second-stage magnetic separator, both of which are wet drum magnetic separators. The feed inlet of the first-stage magnetic separator is connected to the heavy material outlet of the spiral trough separation unit, and the magnetic material outlet of the first-stage magnetic separator is connected to the feed inlet of the second-stage magnetic separator. The non-magnetic material outlet of the first-stage magnetic separator outputs coarse carbon powder. The magnetic material outlet of the second-stage magnetic separator outputs finished iron concentrate, and the non-magnetic material outlet of the second-stage magnetic separator outputs middlings and returns them to the feed inlet of the first-stage magnetic separator for recycling. The magnetic field strength of both the first-stage and second-stage magnetic separators is 1000 Gauss to 4000 Gauss.

7. A wet-process graded resource recovery system for high-zinc ash, zinc, iron, and carbon from a blast furnace according to claim 1, characterized in that, The zinc-containing fine material enrichment and recovery unit includes a sedimentation tank, a first filter press, and a zinc enrichment and concentration device connected in sequence. The inlet of the sedimentation tank is connected to the light material outlet of the spiral trough sorting unit, which is used to allow the zinc-containing slurry to settle naturally. The coarse underflow after sedimentation is discharged as tailings to the solid-liquid separation unit, and the zinc-containing fine particles after sedimentation overflow are transported to the zinc enrichment and concentration device. The zinc enrichment and concentration device is a multi-stage sedimentation and concentration tank or a membrane concentration device, which is used to enrich and concentrate the fine zinc-containing solid material in the overflow. The concentrated zinc concentrate is dewatered by the first filter press and then transported to the finished product storage unit. The concentrated overflow water is transported to the solid-liquid separation unit.

8. A wet-process graded resource recovery system for high-zinc ash, zinc, iron, and carbon from a blast furnace according to claim 1, characterized in that, The solid-liquid separation unit includes a tailings collection tank and a second filter press. The tailwater and tailings generated by the pretreatment screening unit, the spiral flow channel separation unit, the magnetic separation unit, and the zinc-containing fine material enrichment and recovery unit, as well as the wastewater generated during the flushing or venting of each unit in the system, are all collected in the tailings collection tank through pipelines. After being stirred and homogenized, the wastewater is pumped to the second filter press for solid-liquid separation. The second filter press is a plate and frame filter press or a chamber filter press. The filtrate outlet of the second filter press is connected to the water inlet of the wet slurry conditioning unit through a return water pipeline, and the filter cake outlet of the second filter press is connected to a residue collection device.

9. A wet-process graded resource recovery system for high-zinc ash, zinc, iron, and carbon from a blast furnace according to claim 1, characterized in that, The finished product storage unit includes an iron concentrate storage bin, a carbon powder storage bin, and a zinc enrichment storage bin. The iron concentrate storage bin is connected to the iron concentrate outlet of the magnetic separation unit, the carbon powder storage bin is connected to the carbon powder outlet of the magnetic separation unit, and the zinc enrichment storage bin is connected to the zinc enrichment outlet of the zinc-containing fine material enrichment and recovery unit.

10. A wet-process graded resource recovery system for high-zinc ash, zinc, iron, and carbon from a blast furnace according to claim 1, characterized in that, The system also includes a control system, which is electrically connected to the raw material storage unit, the wet slurry preparation unit, the pretreatment screening unit, the spiral flow channel separation unit, the magnetic separation unit, the zinc-containing fine material enrichment and recovery unit, and the solid-liquid separation unit, respectively, for controlling the operation and coordinated operation of each unit.

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