Nonferrous metal smelting slag recovery and treatment system and method

Abstract

The present invention relates to the technical field of metal production or refining, and provides a non-ferrous metal smelting slag recovery and treatment system and method, the method comprising: performing reduction activation treatment on the molten slag, cutting the slag flow by a guide plate and combining mechanical vibration to strengthen the reduction reaction; using ultrasound and gradient magnetic fields to collaboratively sort metal particles; forming a vortex flow field by a rotating spray gun to achieve directional alloy precipitation, and continuously discharging the alloy melt; converting the tailings into glassy building aggregates; recovering the waste heat and quenching the flue gas, using a high-temperature resistant filter bag to capture zinc-containing dust, and then removing sulfides and heavy metals through a graded absorption process. The system comprises an activation reactor, a sorting tower, a precipitation furnace, and a flue gas treatment unit, and each device realizes the collaborative treatment of molten materials through a sealed conveying structure. The present invention realizes the efficient dissociation and recovery of valuable metals, the full-quantity resource utilization of tailings, and the control of the depth of flue gas pollution, significantly improving the resource circulation efficiency and environmental friendliness.

Description

Technical Field

[0001] The present invention relates to the technical field of metal production or refining, and in particular to a system and method for recovering and treating non-ferrous metal smelting slag. Background Art

[0002] Non-ferrous metal smelting slag refers to high-temperature molten waste residue containing metal oxides produced during the smelting process of non-ferrous metals such as copper, zinc, and lead. It usually contains valuable metals such as zinc, copper, and iron, as well as silicate minerals. Based on extensive practical experience, existing traditional slag recovery and treatment technologies have the following main drawbacks:

[0003] The existing reduction process has insufficient gas-solid mass transfer efficiency for molten slag, and the reducing gas is not in sufficient contact with the molten slag, resulting in incomplete dissociation of volatile metal compounds such as zinc. Traditional magnetic separation methods can only separate magnetic metals, and the recovery rate of non-magnetic metals is low; and the cold slag crushing and sorting process is prone to metal oxidation losses. The reheating treatment of the molten slag after cooling consumes a lot of energy. Traditional flue gas treatment systems cannot simultaneously solve the problems of waste heat recovery, heavy metal removal, and harmful gas suppression, resulting in the loss of zinc resources and secondary pollution. Traditional landfill or storage methods fail to realize the resource utilization of waste slag, occupy land, and pollute the environment.

[0004] In summary, it is of great significance to design a non-ferrous metal smelting slag recovery and treatment system and method to solve the above problems. Summary of the Invention

[0005] To solve the problems in the background technology, the present invention provides a method for recovering and treating non-ferrous metal smelting slag, comprising the following steps:

[0006] S1, molten slag reduction activation treatment: molten slag is injected into the activation reactor, and reducing gas CO is sprayed into the slag layer. The molten slag enters the oscillating bed through the porous guide plate, and the oscillating bed is subjected to mechanical vibration to reduce, volatilize and dissociate the zinc compound;

[0007] S2, eddy current-ultrasonic separation: The slag treated in step S1 is fed into an eddy current-ultrasonic separation tower to separate metal particles under the action of ultrasound and gradient magnetic field; the separated metal particles are discharged through the metal microbead outlet at the bottom of the separation tower and enter the microbead collection bin; the remaining separation tailings are fed into the oxygen-enriched rotary blowing precipitation furnace through the separation tailings outlet;

[0008] S3, oxygen-enriched precipitation treatment and alloy recovery: the sorting tailings are placed in an oxygen-enriched rotary blowing precipitation furnace, where oxygen-enriched air is sprayed into the furnace through a rotating lance, and react at high temperature to form an alloy melt. The alloy melt is continuously discharged from the bottom of the precipitation furnace through a siphon device, and the remaining tailings enter the next step of treatment;

[0009] S4, tailings treatment: the tailings discharged from the oxygen-enriched rotary blowing precipitation furnace are quenched by water to form glass particles, which are then crushed and screened to obtain building aggregates;

[0010] S5, flue gas treatment and zinc recovery; the activated flue gas collected in steps S1 and S3 is recycled through a waste heat boiler to form precipitated flue gas, which is rapidly cooled and then enters a bag filter; the bag filter collects ZnO dust; the remaining flue gas enters a desulfurization tower for treatment and then is discharged.

[0011] Furthermore, the specific steps of S1 are as follows:

[0012] S11, a thermocouple temperature sensor array is set in the activation reactor to monitor the temperature in real time and maintain the temperature above the guide plate at 1250±30℃ and the shaking bed area at 1180±20℃;

[0013] S12, when the molten slag flows through the porous guide plate, the porous guide plate is set to have an opening rate of The holes of the guide plate cut the slag flow into multiple thin streams; the inclination angle of the porous guide plate Make the slag slide and flow along the plate surface; adjust the flow rate of the molten slag feed , ensure the slag layer thickness ;

[0014] S13, apply amplitude to the shaking bed ,frequency Mechanical oscillation, activation time is ;

[0015] S14, calculate the activation factor according to the formula:

[0016] ;

[0017] in:

[0018] : Measured temperature of the area above the guide plate;

[0019] : target metal boiling point, i.e., the boiling point of zinc;

[0020] : Heat transfer coefficient, according to the formula Calculated to reflect the opening rate Impact on heat transfer efficiency;

[0021] : Activation time, indicating the residence time of slag in the shaking bed;

[0022] : Specific heat capacity of slag, depends on the slag composition;

[0023] : slag density;

[0024] : Activation factor, target value ≥0.85, characterizes the completeness of zinc volatilization dissociation;

[0025] S15, when When the temperature of the area above the guide plate is raised to , increase the amplitude of the shaking bed to 10 mm and extend the activation time to .

[0026] Furthermore, in S2, before starting the ultrasound, an inert protective gas is injected into the vortex-ultrasonic separation tower to make the oxygen content in the tower ≤50 ppm.

[0027] Furthermore, in S2, metal particles with a particle size greater than 0.5 mm are separated under the action of 20 kHz ultrasound and 0.8-1.2 T gradient magnetic field.

[0028] Furthermore, the specific process of S3 includes:

[0029] S31, the sorting tailings are fed into the oxygen-enriched rotary blowing precipitation furnace, and the furnace temperature is controlled at 1320±20℃;

[0030] S32, oxygen-enriched air with an oxygen content of ≥40 vol% is injected into the upper middle part of the slag layer through a rotating lance with an inclination angle of 25±2°. The nozzle is 0.8m away from the furnace bottom and the lance rotates at a speed of 300±50 rpm to form a vortex flow field to achieve directional reduction and coagulation of the metal;

[0031] S33, stratification of the alloy melt and tailings based on density difference: the alloy melt settles to the bottom of the furnace to form a metal layer, the tailings float above the metal layer, and the agitation range of the spray gun airflow is limited to the middle and upper part of the slag layer;

[0032] S34, real-time monitoring of the thickness of the metal layer at the bottom of the furnace. When the thickness is ≥0.4m, the siphon device is activated to continuously suck out the alloy melt from the middle of the metal layer.

[0033] In step S35, the alloy melt is cooled into an ingot under the protection of argon gas, and the tailings are discharged to the water quenching process.

[0034] Furthermore, in S5, the specific steps of zinc recovery include:

[0035] In step S51, the precipitated flue gas, which has recovered waste heat from the waste heat boiler and rapidly cooled to 200±10°C, is passed through the P84+PTFE coated filter bags of the bag filter at a filtration rate of 0.8-1.2 m / min. The ZnO particles in the flue gas are trapped by the dust layer formed on the surface of the filter bags.

[0036] S52, regularly clean the dust through a 0.5-0.7 MPa pulse compressed air backflush system to allow the accumulated ZnO dust to fall into the dust collection hopper;

[0037] S53, the ZnO dust in the ash hopper is fed into the nitrogen protection storage bin via an airtight screw conveyor, and the oxygen content in the bin is controlled to be ≤100 ppm;

[0038] S54, the dust is subjected to particle size classification, and coarse particles with a particle size of >45μm are screened as raw materials for zinc smelting; fine particles with a particle size of ≤45μm are pressed into 20-50mm cylindrical blocks for use in electrolytic zinc anode plate casting or hot-dip galvanizing alloy raw materials.

[0039] Furthermore, in S5, the desulfurization tower adopts graded absorption, and the pH value of the first-level absorption liquid is maintained at 5.0-5.5 to remove 80% of sulfur dioxide; 0.1 mol / L EDTA chelating agent is added to the second-level absorption liquid to remove residual sulfur dioxide and heavy metal ions.

[0040] The present invention designs a non-ferrous metal smelting slag recovery and treatment system, which includes the following structure:

[0041] An activation reactor equipped with a porous guide plate made of silicon carbide, an oscillating bed, an array of thermocouple temperature sensors, a molten slag outlet, and a volatile gas outlet;

[0042] An eddy current-ultrasonic separation tower has a conical structure and is provided with an ultrasonic transducer array, an electromagnetic coil, a feed inlet, a metal microbead outlet, and a separation tailings outlet;

[0043] An oxygen-enriched rotary blowing precipitation furnace comprises a rotary lance, a siphon device, a feed port, an alloy melt discharge port, a tailings discharge port and an exhaust port;

[0044] A flue gas treatment system comprising a waste heat boiler, a bag dust collector and a desulfurization tower, wherein the bag dust collector is provided with a P84+PTFE coated filter bag, the waste heat boiler is provided with a flue gas inlet and a flue gas outlet, the bag dust collector is provided with a flue gas inlet and a flue gas outlet, and the desulfurization tower is provided with a flue gas inlet and a flue gas outlet;

[0045] Microbead collection chamber, for collecting metal microbeads;

[0046] Insulated pneumatic conveying pipe for conveying molten slag;

[0047] Screw feeder, transporting and sorting tailings;

[0048] Rapid cooling device, flue gas rapid cooling treatment;

[0049] High temperature resistant negative pressure pipeline, transporting volatile gas;

[0050] The molten slag outlet of the activation reactor is connected to the feed inlet of the vortex-ultrasonic separation tower through an insulated pneumatic conveying pipe;

[0051] The metal microbead outlet of the eddy current-ultrasonic separation tower is connected to the microbead collection chamber;

[0052] The sorting tailings outlet of the eddy current-ultrasonic sorting tower is connected to the feed inlet of the oxygen-enriched rotary blowing precipitation furnace through a screw feeder;

[0053] The volatile gas outlet of the activation reactor is connected to the flue gas inlet of the waste heat boiler through a high-temperature resistant negative pressure pipeline;

[0054] The exhaust port of the oxygen-enriched rotary blowing precipitation furnace is connected to the flue gas inlet of the bag filter through a quenching device;

[0055] The flue gas outlet of the waste heat boiler is connected to the flue gas inlet of the bag filter;

[0056] The flue gas outlet of the bag filter is connected to the flue gas inlet of the desulfurization tower.

[0057] Furthermore, in the activation reactor, the porous guide plate is installed 1.2 m directly below the feed inlet with an inclination angle of 45°; the oscillating bed is located 0.5 m below the porous guide plate; the thermocouple temperature sensor array is arranged in two layers, one layer is arranged in the area above the porous guide plate, and the other layer is arranged in the middle area of ​​the oscillating bed.

[0058] The beneficial effects achieved by the present invention are:

[0059] The non-ferrous metal smelting slag recovery and treatment system and method designed in the present invention realizes the full-process resource utilization of slag. It not only efficiently recovers valuable metals, but also converts tailings into high-value building aggregates and produces a variety of by-products, thereby enhancing resource recycling capabilities and providing strong support for the sustainable development of non-ferrous metal smelting. Specifically, it is embodied in:

[0060] First, the present invention designs a molten slag reduction and activation treatment step, uses a porous guide plate to cut the slag flow to increase the gas-solid contact area, and combines mechanical vibration to enhance the diffusion and mass transfer of the reducing gas; by real-time monitoring of temperature and activation factor, dynamically adjusting parameters to ensure that the reaction proceeds fully, significantly improving the efficiency and stability of metal dissociation.

[0061] Second, the present invention designs an eddy current-ultrasonic separation and oxygen-enriched precipitation treatment method, which utilizes the synergistic effect of ultrasonic cavitation and gradient magnetic field to efficiently separate metal particles under the protection of inert gas; at the same time, a vortex flow field is formed by a rotating spray gun to promote the directional reduction and coagulation of the alloy melt, and the alloy is continuously discharged with the help of a siphon device, which significantly enhances the integrity of metal recovery and reduces the loss of valuable metals.

[0062] Third, in the flue gas treatment and zinc recovery links, the present invention designs a waste heat boiler to efficiently recover sensible heat, a quenching device to suppress the generation of harmful substances, a P84+PTFE coated filter bag to efficiently capture dust, and a graded absorption method for the desulfurization tower, which effectively improves the recovery rate of zinc resources, while deeply purifying the flue gas, significantly reducing pollutant emissions, achieving environmentally friendly treatment, and avoiding the risk of resource waste and secondary pollution in traditional flue gas treatment.

[0063] Fourth, the non-ferrous metal smelting slag recovery and treatment system designed by the present invention constructs a molten state full-process resource collaborative processing architecture. Through the synergistic effect of the porous guide plate cutting slag flow of the activation reactor and the mechanical oscillation of the oscillating bed, combined with the dynamic control mechanism of the activation factor, the zinc volatilization efficiency is enhanced; an eddy current-ultrasonic sorting tower is designed, and a gradient magnetic field is used to induce eddy current and ultrasonic cavitation to synergistically separate metal particles, realizing efficient recovery of non-magnetic metals under the protection of inert gas; the oxygen-enriched rotary blowing precipitation furnace promotes directional precipitation of alloys by forming a vortex flow field through an inclined rotating spray gun, and cooperates with a siphon device to continuously discharge the metal melt; the flue gas treatment system integrates waste heat recovery, rapid cooling and poison suppression, high-temperature resistant filter bag graded zinc capture and EDTA complex desulfurization and heavy metal removal methods to form pollution control. This system solves the problems of incomplete metal recovery, large heat energy loss, low tailings utilization rate and serious secondary pollution in traditional processes, and realizes the synergistic efficiency of efficient extraction of valuable metals, full-scale building materialization of tailings and ultra-clean flue gas emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 This is a flow chart of the non-ferrous metal smelting slag recovery and treatment method of the present invention;

[0065] Figure 2 It is a system architecture diagram of the nonferrous metal smelting slag recovery and treatment system of the present invention. DETAILED DESCRIPTION

[0066] The technical solutions of the present invention will be described clearly and completely below in conjunction with the drawings in the present invention. In addition, the forms of the various structures described in the following embodiments are merely examples. The present invention is not limited to the various structures described in the following embodiments. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0067] Reference Figure 1 The present invention provides a method for recovering and treating nonferrous metal smelting slag, comprising the following steps:

[0068] S1, molten slag reduction activation treatment: molten slag is injected into the activation reactor, and reducing gas CO is sprayed into the slag layer. The molten slag enters the oscillating bed through the porous guide plate, and the oscillating bed is subjected to mechanical vibration to reduce, volatilize and dissociate the zinc compound;

[0069] S2, eddy current-ultrasonic separation: The slag treated in step S1 is fed into an eddy current-ultrasonic separation tower to separate metal particles under the action of ultrasound and gradient magnetic field; the separated metal particles are discharged through the metal microbead outlet at the bottom of the separation tower and enter the microbead collection bin; the remaining separation tailings are fed into the oxygen-enriched rotary blowing precipitation furnace through the separation tailings outlet;

[0070] S3, oxygen-enriched precipitation treatment and alloy recovery: the sorting tailings are placed in an oxygen-enriched rotary blowing precipitation furnace, where oxygen-enriched air is sprayed into the furnace through a rotating lance, and react at high temperature to form an alloy melt. The alloy melt is continuously discharged from the bottom of the precipitation furnace through a siphon device, and the remaining tailings enter the next step of treatment;

[0071] S4, tailings treatment: the tailings discharged from the oxygen-enriched rotary blowing precipitation furnace are quenched by water to form glass particles, which are then crushed and screened to obtain building aggregates;

[0072] S5, flue gas treatment and zinc recovery; the activated flue gas collected in steps S1 and S3 is recycled through a waste heat boiler to form precipitated flue gas, which is rapidly cooled and then enters a bag filter; the bag filter collects ZnO dust; the remaining flue gas enters a desulfurization tower for treatment and then is discharged.

[0073] The specific steps of S1 are as follows:

[0074] S11, a thermocouple temperature sensor array is set in the activation reactor to monitor the temperature in real time and maintain the temperature above the guide plate at 1250±30℃ and the shaking bed area at 1180±20℃;

[0075] S12, when the molten slag flows through the porous guide plate, the porous guide plate is set to have an opening rate of The holes of the guide plate cut the slag flow into multiple thin streams; the inclination angle of the porous guide plate Make the slag slide and flow along the plate surface; adjust the flow rate of the molten slag feed , ensure the slag layer thickness ;

[0076] S13, apply amplitude to the shaking bed ,frequency Mechanical oscillation, activation time is ;

[0077] S14, calculate the activation factor according to the formula:

[0078] ;

[0079] in:

[0080] : The measured temperature of the area above the guide plate (unit: °C). The actual temperature of the molten slag is directly measured by a thermocouple;

[0081] : Target metal boiling point (unit: °C), zinc is 907 °C, representing the minimum temperature threshold required for metal volatilization;

[0082] : Heat transfer coefficient (unit: s⁻¹), from the formula Calculated to reflect the opening rate (Unit: %) Impact on heat transfer efficiency;

[0083] : Activation time (unit: s), the value is 90±10 seconds, which means the residence time of slag in the shaking bed;

[0084] : Specific heat capacity of slag (unit: J / (kg·K)), depends on the slag composition, typical values ​​are 0.8–1.2 kJ / (kg·K);

[0085] : Slag density (unit: kg / m³), typical value is 2800–3200 kg / m³, positively correlated with the metal oxide content;

[0086] : Activation factor (dimensionless), target value ≥ 0.85, characterizes the completeness of zinc volatilization dissociation;

[0087] S15, when When the temperature of the area above the guide plate is raised to , increase the amplitude of the shaking bed to 10 mm and extend the activation time to .

[0088] In S2, before starting the ultrasound, an inert protective gas is injected into the vortex-ultrasonic separation tower to make the oxygen content in the tower ≤50ppm.

[0089] In S2, metal particles with a particle size greater than 0.5 mm are separated under the action of 20 kHz ultrasound and 0.8-1.2 T gradient magnetic field.

[0090] The specific process of S3 includes:

[0091] S31, the sorting tailings are fed into the oxygen-enriched rotary blowing precipitation furnace, and the furnace temperature is controlled at 1320±20℃;

[0092] S32, oxygen-enriched air with an oxygen content of ≥40 vol% is injected into the upper middle part of the slag layer through a rotating lance with an inclination angle of 25±2°. The nozzle is 0.8m away from the furnace bottom and the lance rotates at a speed of 300±50 rpm to form a vortex flow field to achieve directional reduction and coagulation of the metal;

[0093] S33, stratification of the alloy melt and tailings based on density difference: the alloy melt settles to the bottom of the furnace to form a metal layer, the tailings float above the metal layer, and the agitation range of the spray gun airflow is limited to the middle and upper part of the slag layer;

[0094] S34, real-time monitoring of the thickness of the metal layer at the bottom of the furnace. When the thickness is ≥0.4m, the siphon device is activated to continuously suck out the alloy melt from the middle of the metal layer.

[0095] In step S35, the alloy melt is cooled into an ingot under the protection of argon gas, and the tailings are discharged to the water quenching process.

[0096] In S5, the specific steps of zinc recovery include:

[0097] In step S51, the precipitated flue gas, which has recovered waste heat from the waste heat boiler and rapidly cooled to 200±10°C, is passed through the P84+PTFE coated filter bags of the bag filter at a filtration rate of 0.8-1.2 m / min. The ZnO particles in the flue gas are trapped by the dust layer formed on the surface of the filter bags.

[0098] S52, regularly clean the dust through a 0.5-0.7 MPa pulse compressed air backflush system to allow the accumulated ZnO dust to fall into the dust collection hopper;

[0099] S53, the ZnO dust in the ash hopper is fed into the nitrogen protection storage bin via an airtight screw conveyor, and the oxygen content in the bin is controlled to be ≤100 ppm;

[0100] S54, the dust is subjected to particle size classification, and coarse particles with a particle size of >45μm are screened as raw materials for zinc smelting; fine particles with a particle size of ≤45μm are pressed into 20-50mm cylindrical blocks for use in electrolytic zinc anode plate casting or hot-dip galvanizing alloy raw materials.

[0101] In S5, the desulfurization tower uses a staged absorption process. The pH value of the first absorption liquid is maintained at 5.0-5.5, removing 80% of sulfur dioxide. The second absorption liquid is added with 0.1 mol / L EDTA chelating agent to remove residual sulfur dioxide and heavy metal ions. EDTA chelating agent is a chemical reagent, the full name of which is ethylenediaminetetraacetic acid. It has multiple coordination groups and can form stable complexes with various metal ions. EDTA chelating agent is used in the second absorption process of the desulfurization tower. Flue gas may contain Cd 2+ 、As 3+ EDTA can form stable complexes with these heavy metal ions, thereby removing them from flue gas and preventing their release into the environment and causing pollution. EDTA complexing agents can also react with some sulfur oxides, converting them into more soluble and absorbable forms, thereby improving the desulfurization tower's sulfur dioxide removal efficiency.

[0102] Reference Figure 2The present invention also designs a non-ferrous metal smelting slag recovery and treatment system, which includes the following structures: an activation reactor, which is provided with a porous guide plate made of silicon carbide, an oscillating bed, a thermocouple temperature sensor array, a molten slag outlet and a volatile gas outlet; an eddy current-ultrasonic sorting tower, which has a conical structure and is provided with an ultrasonic transducer array, an electromagnetic coil, a feed inlet, a metal microbead outlet and a sorting tailings outlet; an oxygen-enriched rotary blowing precipitation furnace, which includes a rotary lance, a siphon device, a feed inlet, an alloy melt outlet, a tailings outlet and an exhaust port; a smoke The gas treatment system includes a waste heat boiler (HRSG), a bag-type dust collector, and a desulfurization tower. The bag-type dust collector is equipped with P84+PTFE coated filter bags. The HRSG has a flue gas inlet and outlet. The bag-type dust collector has a flue gas inlet and outlet. The desulfurization tower also has a flue gas inlet and outlet. A microbead collection bin collects metal microbeads; an insulated pneumatic conveying pipe conveys molten slag; a screw feeder conveys sorted tailings; a quenching device for rapid flue gas cooling; and a high-temperature, negative pressure pipe for conveying volatile gases. The P84+PTFE coated filter bag is a high-performance industrial filter material that combines P84 high-temperature, heat-resistant fiber with PTFE (polytetrafluoroethylene) film. P84 fiber has excellent high-temperature resistance, with a long-term operating temperature of 240°C to 260°C and a short-term temperature resistance of up to 280°C. It maintains good stability in high-temperature environments. Its unique trilobate cross-section increases the filtration area and improves filtration efficiency. P84 fiber also offers chemical and abrasion resistance. PTFE film exhibits excellent chemical stability, corrosion resistance, and high-temperature resistance. It can withstand corrosive substances such as strong acids and alkalis. Its smooth surface and low friction coefficient make it less susceptible to dust adhesion and easier to clean. It also imparts excellent hydrophobicity to the filter bag, enabling stable operation in humid or oily conditions.

[0103] The molten slag outlet of the activation reactor is connected to the feed inlet of the vortex-ultrasonic separation tower through an insulated pneumatic conveying pipe; the metal microbead outlet of the vortex-ultrasonic separation tower is connected to the microbead collection bin; the separation tailings outlet of the vortex-ultrasonic separation tower is connected to the feed inlet of the oxygen-enriched rotary blowing precipitation furnace through a screw feeder; the volatile gas outlet of the activation reactor is connected to the flue gas inlet of the waste heat boiler through a high-temperature resistant negative pressure pipe; the exhaust port of the oxygen-enriched rotary blowing precipitation furnace is connected to the flue gas inlet of the bag filter through a quenching device; the flue gas outlet of the waste heat boiler is connected to the flue gas inlet of the bag filter; and the flue gas outlet of the bag filter is connected to the flue gas inlet of the desulfurization tower. In the activation reactor, the porous guide plate is installed 1.2m directly below the feed inlet with an inclination of 45°; the oscillating bed is located 0.5m below the porous guide plate; and the thermocouple temperature sensor array is arranged in two layers, one layer is arranged in the area above the porous guide plate, and the other layer is arranged in the middle area of ​​the oscillating bed.

[0104] During the implementation of the non-ferrous metal smelting slag recovery method of the present invention, the reaction process and principle of steps S1 to S5 are as follows:

[0105] S1, after the molten slag is injected into the activation reactor, the reducing gas CO is sprayed into the slag layer, where it undergoes a gas-solid reduction reaction with the zinc compound. Under the high temperature conditions of 1250±30°C above the guide plate and 1180±20°C on the oscillating bed, the zinc metal oxide is reduced to a gaseous metal element. The porous guide plate is designed at a 45° angle to allow the slag to form a thin layer of slip flow, and its open pore structure cuts the slag flow into fine strands, increasing the gas-slag contact area. The oscillating bed applies mechanical vibrations with an amplitude of 8mm and a frequency of 15Hz, causing the slag particles to collide and rub violently, enhancing the diffusion and mass transfer of the reducing gas and promoting the volatilization and dissociation of zinc. The thermocouple temperature sensor array monitors the temperature distribution in real time, providing data support for the calculation of the activation factor λ. When λ<0.85, the temperature is increased, the amplitude is increased, and the time is extended to ensure the metal volatilization efficiency.

[0106] S2, the activated slag enters the eddy current-ultrasonic separation tower, and inert gas is injected into the tower to maintain the oxygen content ≤50ppm to prevent metal oxidation; the ultrasonic transducer array emits 20kHz high-frequency sound waves to generate cavitation bubbles in the slag, and when the bubbles collapse, shock waves are released to break up the particle agglomerates; the electromagnetic coil generates a 0.8-1.2T gradient magnetic field. When conductive metal particles pass through, the alternating magnetic field induces eddy currents inside them. The eddy currents interact with the magnetic field to form a Lorentz force, pushing the metal particles to jump to the low magnetic field area; non-metallic slag particles are non-conductive and only settle under the action of gravity; the conical tower bottom design combined with a 60° inclination angle uses gravity separation to make metal microbeads with a particle size >0.5mm slide along the slope into the collection bin, and the tailings are discharged through the middle outlet.

[0107] In the above process, the gradient magnetic field induces closed eddy currents inside the conductive metal particles, and the direction of the current is perpendicular to the magnetic field; according to Lenz's law, the induced magnetic field generated by the eddy current interacts with the external magnetic field, generating a Lorentz force perpendicular to the direction of particle movement, causing the metal particles to bounce; the non-conductive slag particles settle only due to gravity and fluid resistance, and the difference in motion trajectories realizes efficient separation of metal and non-metal; the ultrasonic cavitation effect further eliminates the agglomeration of fine particles and improves the sorting accuracy.

[0108] S3, the sorting tailings are fed into the oxygen-enriched rotary blowing precipitation furnace, and the furnace temperature is maintained at 1320±20℃; the rotary spray gun sprays oxygen-enriched air with an oxygen content of ≥40% at an inclination angle of 25±2°, the nozzle is 0.8m away from the furnace bottom, and the spray gun rotates at 300±50rpm to form a vortex flow field, which strengthens the gas-liquid mass transfer between oxygen and residual metal oxides, so that the metal oxides are reduced to liquid alloy; based on the density difference, the alloy melt settles to the bottom of the furnace to form a metal layer, and the tailings float on the upper layer; the oxygen analysis probe monitors the oxygen potential of the slag layer in real time to ensure sufficient reduction reaction; the siphon device is started when the metal layer thickness is ≥0.4m, and the alloy melt is continuously sucked out from the middle to avoid mixing of the slag layer.

[0109] S4, the tailings discharged from the sedimentation furnace are rapidly cooled by water quenching. The high-temperature molten slag undergoes a glass transition when it comes into contact with water, forming amorphous glass particles; after crushing and screening, homogeneous building aggregates are obtained, realizing the resource utilization of waste slag.

[0110] The flue gas generated in steps S5, S1 and S3 enters the waste heat boiler to recover sensible heat. After cooling, the flue gas is quenched by a quenching device to suppress the formation of dioxins; the flue gas at 200±10℃ is passed into the bag dust collector, and the P84+PTFE coated filter bag efficiently captures ZnO particles due to its high temperature resistance and hydrophobic properties. The pulse backflushing system regularly removes dust accumulated in the filter bags; the collected ZnO dust is classified under nitrogen protection, and the coarse particles (>45μm) are directly recycled for smelting, and the fine particles (≤45μm) are briquetted for electrolytic zinc anode or galvanizing raw materials; the remaining flue gas enters the desulfurization tower, and the first-level absorption liquid has a pH of 5.0-5.5 to remove 80% of SO2. The secondary absorption liquid is added with EDTA chelating agent to chelate residual SO2 and heavy metal ions such as Cd ions and As ions to achieve deep purification of pollutants.

[0111] Example 1. The following describes the non-ferrous metal smelting slag recovery and treatment system of the present invention through a specific embodiment. The non-ferrous metal smelting slag recovery and treatment system of this embodiment is composed of an activation reactor, an eddy current-ultrasonic separation tower, an oxygen-enriched rotary blowing precipitation furnace, a flue gas treatment system, and auxiliary units. The activation reactor is equipped with a porous guide plate and an oscillating bed made of silicon carbide, with a volatile gas outlet at the top and a molten slag outlet at the bottom; the guide plate is located 1.2 meters below the feed inlet and has an inclination angle of 45 degrees, and the oscillating bed is located 0.5 meters below the guide plate; an array of thermocouple temperature sensors is arranged in two layers above the guide plate and in the middle of the oscillating bed. The eddy current-ultrasonic separation tower is a conical structure with an integrated ultrasonic transducer array. A coil and electromagnetic coil are arranged every 1.5 meters along the tower's height, with the number of turns decreasing from base to top. The conical section at the bottom of the tower is inclined at 60° and connected to the microbead collection bin at a 30° angle to the horizontal. The tower body is equipped with a feed inlet, a tailings outlet for separation, located 1.5 meters above the conical base, and a metal microbead outlet. The oxygen-enriched rotary precipitation furnace includes a rotary lance inserted 2.8 meters from the furnace top, with the nozzle 0.8 meters from the furnace bottom, a siphon device, a feed inlet, an alloy melt outlet, a tailings outlet, and an exhaust port located on the side of the furnace top. An oxygen analyzer probe is installed 0.3 meters below the lance at a 45° angle to the lance axis. The flue gas treatment system consists of a waste heat boiler, a flue gas inlet and outlet, a bag filter with P84+PTFE coated filter bags, a flue gas inlet and outlet, a desulfurization tower with a flue gas inlet and outlet, and a quenching device. The auxiliary unit includes a microbead collection bin, an insulated pneumatic conveying pipe with an inner diameter of 300 mm, a length of 8 m, an insulation layer of 50 mm thick, a screw feeder and a high-temperature resistant negative pressure pipe, connected at a 30° inclination angle.

[0112] The molten slag outlet of the activation reactor is connected to the sorting tower feed via an insulated pneumatic conveying pipe; the metal microbead outlet of the sorting tower is connected to the microbead collection bin, and the sorting tailings outlet is connected to the precipitation furnace feed via a screw feeder. The volatile gas outlet of the activation reactor is connected to the exhaust gas inlet of the waste heat boiler via a high-temperature negative pressure pipe; the exhaust outlet of the precipitation furnace is connected to the exhaust gas inlet of the bag filter through a quenching device; the exhaust gas outlet of the waste heat boiler is connected to the exhaust gas inlet of the bag filter; and the exhaust gas outlet of the bag filter is connected to the exhaust gas inlet of the desulfurization tower. The activation reactor uses porous guide plates to cut the molten slag into fine streams. Combined with the mechanical vibration of the shaking bed and the injection of reducing gas, it achieves efficient reduction and volatilization of zinc compounds. Temperature sensors monitor the temperature in key areas in real time, providing a basis for adjustment of the control system. The eddy current-ultrasonic sorting tower utilizes the synergistic effect of ultrasonic cavitation and gradient magnetic field to efficiently separate metal particles in a composite force field. The conical bottom design and inclination optimize the guidance and collection of microbeads, and the inert gas protects the environment from metal oxidation. The oxygen-enriched rotary precipitation furnace uses a rotating lance to create a vortex flow field, enhancing the reduction of metal oxides and the coagulation of the alloy melt. A siphon device enables continuous discharge of the alloy melt, and a layered structural design ensures efficient separation of tailings and alloy. The flue gas treatment system uses a waste heat boiler to recover sensible heat from the flue gas, while a quenching device suppresses dioxin formation. P84+PTFE-coated filter bags, with their high-temperature and corrosion-resistant properties, efficiently capture ZnO dust. The desulfurization tower's graded absorption design simultaneously removes sulfur and heavy metals. The control system dynamically adjusts activation parameters based on the activation factor λ: when λ < 0.85, it automatically increases the temperature above the guide plate, increases the amplitude, and prolongs the time to ensure zinc volatilization efficiency. An oxygen analysis probe is coupled with inert gas injection to maintain a low-oxygen environment in the separation tower. Metal layer thickness monitoring triggers the start and stop of the siphon device to ensure continuous alloy production.

[0113] The non-ferrous metal smelting slag recovery and treatment system of this embodiment significantly improves the recovery rate of valuable metals through the coordinated design of multi-stage reaction and separation units; the process connection of activation-sorting-precipitation reduces heat energy loss; the flue gas treatment unit realizes zinc resource recovery and deep purification of pollutants; the automated control system ensures stable operation of the process and reduces the intensity of manual intervention.

[0114] Example 2: This example takes the molten slag of a nonferrous metal smelter as the treatment object, which contains ZnO, Pb, Cu, Fe, SiO2, CaO, Al2O3 and other components. The method of the present invention is used for recovery and treatment. The specific process is as follows:

[0115] S1 Reduction and activation treatment: The molten slag is injected into the activation reactor at a flow rate of 0.8 m³ / min, and CO reducing gas is sprayed in at the same time. , with an inclination of 45°, the slag flow was cut into thin strands, the temperature above the guide plate was controlled at 1250°C, and the shaking bed temperature was maintained at 1180°C. Mechanical vibration with an amplitude of 8 mm and a frequency of 15 Hz was applied for 90 seconds to calculate the activation factor ,>0.85, meets the requirements.

[0116] S2 Eddy Current-Ultrasonic Separation: The activated slag is conveyed into an eddy current-ultrasonic separation tower via an insulated pneumatic conveying pipe. Nitrogen is injected to reduce the oxygen content in the tower to 45 ppm. A 20 kHz ultrasonic wave and a 1.0 T gradient magnetic field are used to separate metal particles with a size greater than 0.5 mm, primarily Cu and Fe microbeads. The metal microbeads are discharged from the conical bottom outlet into a collection bin.

[0117] S3 oxygen-enriched precipitation treatment: The sorting tailings are fed into the oxygen-enriched rotary blowing precipitation furnace through a screw feeder, and the furnace temperature is controlled at 1320℃.

[0118] A rotating lance, tilted at 25° and rotating at 300 rpm, injects oxygen-enriched air with a 45% oxygen content. The nozzle is 0.8 m from the furnace bottom, creating a vortex flow field that promotes alloy reduction and precipitation. A siphon device activates when the metal layer reaches a thickness of 0.4 m, continuously sucking out the molten alloy.

[0119] S4 tailings treatment: The remaining tailings are quenched with water to form glassy particles, which are then crushed and screened to obtain 5-20 mm building aggregates.

[0120] S5 flue gas treatment: S1 and S3 flue gases are recovered through a waste heat boiler, rapidly cooled to 200°C, and then passed into a bag filter. P84+PTFE-coated filter bags capture ZnO dust, which is then cleaned with pulse backflushing and collected. The flue gas enters a desulfurization tower, where a primary absorption solution (pH=5.2) removes 82% of sulfur dioxide. A secondary addition of 0.1 mol / L EDTA removes residual sulfur dioxide and heavy metals.

[0121] Comparative Example 1: The same molten slag from a nonferrous metal smelter as in Example 2 was treated using a conventional reduction smelting + magnetic separation method. The process involved direct reduction smelting: the same batch of molten slag was injected into a conventional reduction furnace, sprayed with coke powder and air, and reacted at 1350°C for 60 minutes. The slag was then water quenched, crushed, and subjected to magnetic separation in a 0.5 T magnetic field to separate the metal particles. The magnetic separation tailings were directly landfilled; the flue gas was dedused using conventional polyester filter bags and desulfurized with lime milk.

[0122] Table 1 Experimental results of Example 1 and Comparative Example 1

[0123]

[0124] From the comparison of Example 2 and Comparative Example 1, it can be seen that the activation treatment of the present invention significantly improves the gas-solid reaction efficiency by cutting the slag flow with a porous guide plate + mechanical vibration, and the zinc volatilization rate is increased by 19.8%. The eddy current-ultrasonic sorting tower uses a gradient magnetic field to induce eddy currents, the closed current inside the metal particles and the magnetic field repel each other, and the ultrasonic cavitation synergistic effect greatly improves the recovery rate of non-magnetic metals such as copper, solving the limitations of traditional magnetic separation. The vitrification of tailings realizes the conversion of building aggregates and avoids landfill pollution. The high temperature resistance of P84+PTFE filter bags and EDTA complexing of heavy metals in flue gas treatment make the pollutant emission indicators comprehensively superior to traditional methods. The recovery method of the present invention adds alloy products, and at the same time, ZnO dust is graded and utilized, coarse particles are recycled, and fine particles are pressed into blocks, realizing resource recycling and value-added.

[0125] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for recovering and treating non-ferrous metal smelting slag, characterized in that: The following steps are involved: S1, molten slag reduction activation treatment; the molten slag is injected into the activation reactor, which is equipped with a porous guide plate and a vibrating bed made of silicon carbide. In the activation reactor, the porous guide plate is installed 1.2m below the feed inlet at an inclination angle of 45°; the vibrating bed is located 0.5m below the porous guide plate. Simultaneously, reducing gas CO is sprayed into the slag, and the molten slag enters the vibrating bed through the porous guide plate, applying mechanical vibration to the vibrating bed, causing the zinc compound to be reduced, volatilized and dissociated. S2, eddy current-ultrasonic separation; the slag treated in step S1 is fed into an eddy current-ultrasonic separation tower to separate metal particles under the action of ultrasound and gradient magnetic fields; the separated metal particles are discharged through the metal microbead outlet at the bottom of the separation tower and enter the microbead collection bin; the remaining separation tailings enter the oxygen-enriched rotary blowing precipitation furnace through the separation tailings outlet; S3, oxygen-enriched precipitation treatment and alloy recovery: the sorting tailings are placed in an oxygen-enriched rotary precipitation furnace, where oxygen-enriched air is sprayed into the furnace through a rotating lance, and react at high temperature to form an alloy melt; the alloy melt is continuously discharged from the bottom of the precipitation furnace through a siphon device, and the remaining tailings enter the next step of treatment; S4, tailings treatment: the tailings discharged from the oxygen-enriched rotary blowing precipitation furnace are quenched by water to form glass particles, which are then crushed and screened to obtain building aggregates; S5, flue gas treatment and zinc recovery; the activated flue gas collected in steps S1 and S3 is recycled through a waste heat boiler to form precipitated flue gas, which is rapidly cooled and then enters a bag filter; the bag filter collects ZnO dust; the remaining flue gas enters a desulfurization tower for treatment and then is discharged.

2. The method according to claim 1, characterized in that The specific steps of S1 are as follows: S11, a thermocouple temperature sensor array is set in the activation reactor to monitor the temperature in real time and maintain the temperature above the guide plate at 1250±30℃ and the shaking bed area at 1180±20℃; S12, when the molten slag flows through the porous guide plate, the porous guide plate is set to have an opening rate of The holes of the guide plate cut the slag flow into multiple thin streams; the inclination angle of the porous guide plate Make the slag slide and flow along the plate surface; Adjust the molten slag feed flow rate , ensure the slag layer thickness ; S13, apply amplitude to the shaking bed ,frequency Mechanical oscillation, activation time is ; S14, calculate the activation factor according to the formula: ； in: : Measured temperature of the area above the guide plate; : target metal boiling point, i.e., the boiling point of zinc; : Heat transfer coefficient, according to the formula Calculated to reflect the opening rate Impact on heat transfer efficiency; : Activation time, indicating the residence time of slag in the shaking bed; : Specific heat capacity of slag, depends on the slag composition; : slag density; : Activation factor, target value ≥0.85, characterizes the completeness of zinc volatilization dissociation; S15, when When the temperature of the area above the guide plate is raised to , increase the amplitude of the shaking bed to 10mm, and extend the activation time to .

3. The method according to claim 1, characterized in that In S2, before starting the ultrasound, an inert protective gas is injected into the vortex-ultrasonic separation tower to make the oxygen content in the tower ≤50 ppm.

4. The method according to claim 1, characterized in that In S2, metal particles with a particle size greater than 0.5 mm are separated under the action of 20 kHz ultrasound and 0.8-1.2 T gradient magnetic field.

5. The method according to claim 1, characterized in that: The specific process of S3 includes: S31, the sorting tailings are fed into the oxygen-enriched rotary blowing precipitation furnace, and the furnace temperature is controlled at 1320±20℃; S32, oxygen-enriched air with an oxygen content of ≥40 vol% is injected into the upper middle part of the slag layer through a rotating lance with an inclination angle of 25±2°. The nozzle is 0.8m away from the furnace bottom and the lance rotates at a speed of 300±50 rpm to form a vortex flow field to achieve directional reduction and coagulation of the metal; S33, stratification of the alloy melt and tailings based on density difference: the alloy melt settles to the bottom of the furnace to form a metal layer, the tailings float above the metal layer, and the agitation range of the spray gun airflow is limited to the middle and upper part of the slag layer; S34, real-time monitoring of the thickness of the metal layer at the bottom of the furnace. When the thickness is ≥0.4m, the siphon device is activated to continuously suck out the alloy melt from the middle of the metal layer. In step S35, the alloy melt is cooled into an ingot under the protection of argon gas, and the tailings are discharged to the water quenching process.

6. The method according to claim 1, characterized in that In S5, the specific steps of zinc recovery include: In step S51, the precipitated flue gas, which has recovered waste heat from the waste heat boiler and rapidly cooled to 200±10°C, is passed through the P84+PTFE coated filter bags of the bag filter at a filtration rate of 0.8-1.2 m / min. The ZnO particles in the flue gas are trapped by the dust layer formed on the surface of the filter bags. S52, regularly clean the dust through a 0.5-0.7 MPa pulse compressed air backflush system to allow the accumulated ZnO dust to fall into the dust collection hopper; S53, the ZnO dust in the ash hopper is fed into the nitrogen protection storage bin via an airtight screw conveyor, and the oxygen content in the bin is controlled to be ≤100ppm; S54, the dust is subjected to particle size classification, and coarse particles with a particle size of >45μm are screened as raw materials for zinc smelting; fine particles with a particle size of ≤45μm are pressed into 20-50mm cylindrical blocks for use in electrolytic zinc anode plate casting or hot-dip galvanizing alloy raw materials.

7. The method according to claim 1, characterized in that: In S5, the desulfurization tower adopts graded absorption. The pH value of the first-stage absorption liquid is maintained at 5.0-5.5, removing 80% of sulfur dioxide; 0.1 mol / L EDTA chelating agent is added to the second-stage absorption liquid to remove residual sulfur dioxide and heavy metal ions.

8. A non-ferrous metal smelting slag recovery and treatment system for implementing the method according to any one of claims 1 to 7, characterized in that: Includes the following structure: An activation reactor equipped with a porous guide plate made of silicon carbide, an oscillating bed, an array of thermocouple temperature sensors, a molten slag outlet, and a volatile gas outlet; An eddy current-ultrasonic separation tower has a conical structure and is provided with an ultrasonic transducer array, an electromagnetic coil, a feed inlet, a metal microbead outlet, and a separation tailings outlet; An oxygen-enriched rotary blowing precipitation furnace comprises a rotary lance, a siphon device, a feed port, an alloy melt discharge port, a tailings discharge port and an exhaust port; A flue gas treatment system comprising a waste heat boiler, a bag dust collector and a desulfurization tower, wherein the bag dust collector is provided with a P84+PTFE coated filter bag, the waste heat boiler is provided with a flue gas inlet and a flue gas outlet, the bag dust collector is provided with a flue gas inlet and a flue gas outlet, and the desulfurization tower is provided with a flue gas inlet and a flue gas outlet; Microbead collection chamber, for collecting metal microbeads; Insulated pneumatic conveying pipe for conveying molten slag; Screw feeder, transporting and sorting tailings; Rapid cooling device, flue gas rapid cooling treatment; High temperature resistant negative pressure pipeline, transporting volatile gas; The molten slag outlet of the activation reactor is connected to the feed inlet of the vortex-ultrasonic separation tower through an insulated pneumatic conveying pipe; The metal microbead outlet of the eddy current-ultrasonic separation tower is connected to the microbead collection chamber; The sorting tailings outlet of the eddy current-ultrasonic sorting tower is connected to the feed inlet of the oxygen-enriched rotary blowing precipitation furnace through a screw feeder; The volatile gas outlet of the activation reactor is connected to the flue gas inlet of the waste heat boiler through a high-temperature resistant negative pressure pipeline; The exhaust port of the oxygen-enriched rotary blowing precipitation furnace is connected to the flue gas inlet of the bag filter through a quenching device; The flue gas outlet of the waste heat boiler is connected to the flue gas inlet of the bag filter; The flue gas outlet of the bag filter is connected to the flue gas inlet of the desulfurization tower.

9. The system according to claim 8, characterized in that: The thermocouple temperature sensor array is arranged in two layers, one layer is arranged in the area above the porous guide plate, and the other layer is arranged in the middle area of ​​the shaking bed.

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