A method and system for resource utilization of dust ash solid waste

Abstract

The present application provides a method for resource utilization of dust ash solid waste, including raw material pre-washing and filtration process, potassium chloride soaking and evaporation process, raw material storage process, premixing process, ingredient supply process, mixing process, roasting and reduction process, slag cooling process, flue gas cooling waste heat recovery process and flue gas desulfurization zinc collection process, premixing dust ash filtration sludge, etc., control the uniformity of moisture, add reducing agent and heating agent after ingredient mixing, and send to roasting and reduction system for reduction roasting, chloride ion, sulfur and zinc oxide are vaporized and discharged from the kiln with flue gas, zinc oxide is collected, and iron-containing kiln slag is obtained after cooling, and sintering, blast furnace and steelmaking raw materials with an iron grade of about 50% are obtained. The present invention adopts wet-based water washing and rotary kiln fire method to remove zinc, potassium, sodium and chlorine, so as to achieve the purpose of recovering iron-containing materials; under the condition of ensuring that the zinc removal rate is 92%, the effective separation of iron, zinc, potassium and sodium is achieved, and the comprehensive utilization of resources is realized.

Description

Technical Field

[0001] The present invention relates to the field of solid waste resource utilization, and in particular to a dust ash solid waste resource utilization method and system. Background Art

[0002] At present, most enterprises mainly deal with dust by returning it to raw materials. This method not only makes it difficult to fully utilize the useful elements in the dust, but also affects the quality of sintered ore, and thus affects the operation of the blast furnace. Even the dust in many steel mills is simply piled up, causing serious environmental pollution and making the problems of land occupation and secondary resource waste increasingly serious.

[0003] The core of dust resource utilization is to fully recycle the iron, valuable metals and other elements in the dust, while separating and comprehensively utilizing harmful elements that cannot be recycled in steel production. Effective industrial solid waste treatment is a difficult problem that must be solved for clean production and sustainable development in the steel industry.

[0004] In the current steel industry, the continuous cycle enrichment of zinc metal and alkali metal in steel plant dust not only seriously affects the normal production operation of blast furnaces, but also has a great impact on the life of blast furnaces, causing huge economic losses to enterprises and society. Chinese patent CN116287692A discloses a method for utilizing metallurgical solid waste, which includes: step A: utilizing solid waste generated in the production process of steel enterprises as raw materials, step B: processing into iron slag through high-temperature roasting in a rotary kiln, step C: screening the iron slag, after the iron slag is screened, the iron slag with a particle size of ≥150mm is added to the scrap steel as a raw material for steelmaking and fed into the converter; the iron slag with a particle size of <150mm is used as a coolant to replace the iron ore or sintered ore originally used in converter steelmaking for cooling. Chinese patent CN109097588B proposes a device and method for resource utilization of iron-containing and zinc-containing solid wastes. After pretreatment, iron-containing and zinc-containing solid wastes and other wastes are added with binders and coke powder to be pressed into balls. After drying, they are put into an annular pre-reduction furnace for pre-reduction. The reduced pre-reduction raw materials are pressed into blocks or directly put into a final reduction smelting furnace for reduction and smelting into molten iron and slag. The flue gas of the annular pre-reduction furnace is recovered through waste heat and collected by a dust collector to obtain a zinc oxide-rich product. However, in the above method, only zinc and iron elements are recovered, and other valuable substances in the solid waste are not recovered, and energy conservation and efficient utilization are not involved in the solid waste recycling process. Summary of the invention

[0005] The purpose of the present invention is to provide a method and system for resource utilization of dust ash solid waste, so as to realize large-scale treatment of steel plant waste dust ash, solve the problems of dust waste stacking occupying land and polluting the environment; avoid the circulation of zinc-containing dust within the steel enterprise, thereby increasing the service life of its blast furnace, and at the same time comprehensively utilize resources to produce certain economic benefits.

[0006] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0007] A method for resource utilization of dust ash solid waste, comprising: a raw material pre-washing and filtration process, a potassium chloride leaching and evaporation process, a raw material storage process, a premixing process, a material supply process, a mixing process, a roasting and reduction process, a slag cooling process, a flue gas cooling waste heat recovery process and a flue gas desulfurization and zinc recovery process;

[0008] Raw material pre-washing and filtration process: including the multi-stage washing process of machine head ash and the multi-stage washing process of blast furnace bag ash;

[0009] Potassium chloride washing and evaporation process: The filtrate obtained in the head ash multi-stage water washing process is pre-treated and initially concentrated, and then evaporated, concentrated and fractionated and crystallized to obtain the product industrial potassium chloride and the by-products sodium chloride and sodium sulfate;

[0010] Raw material storage process: storing the filter residue, gravity ash and steelmaking ash from the multi-stage water washing process of blast furnace bag ash;

[0011] Premixing process: premixing the filter residue, including salt extraction filter press mud, blast furnace sludge and converter sludge, controlling the moisture content to be uniform, and obtaining a premix;

[0012] The process of providing ingredients, mixing materials and roasting and reducing materials is as follows: adding reducing agent and heating agent into the premix, mixing well, and then performing reduction roasting on the materials;

[0013] Slag cooling process: Cool the material obtained by reduction roasting to obtain iron-containing slag, crush the iron-containing slag, magnetically separate and briquette to obtain steelmaking raw materials with an iron content of about 50%;

[0014] Flue gas cooling waste heat recovery process: The heat obtained from slag cooling and the waste heat from flue gas cooling are recovered and used in the potassium chloride leaching and evaporation process;

[0015] Flue gas desulfurization and zinc collection process: The flue gas generated by the reduction roasting of the material is collected after sedimentation to obtain secondary zinc oxide, and the remaining gas is discharged after desulfurization and denitrification.

[0016] Preferably, in the multi-stage water washing process of blast furnace bag ash, the blast furnace sludge is washed with water for three stages, the slurry after water washing enters the filter press for mud and water separation, the filtrate after separation returns to the secondary water washing, the filtrate of the secondary water washing slurry after separation by the filter press returns to the primary water washing, and the filtrate of the primary water washing slurry is used as the final filtrate for the multi-stage water washing process of the head ash;

[0017] The primary washing slurry filtrate in the multi-stage washing process of blast furnace bag ash is used in the multi-stage washing process of engine head ash to perform secondary washing of the engine head ash; the filtrate obtained in the multi-stage washing process of engine head ash enters the potassium chloride leaching and evaporation process.

[0018] Preferably, in the roasting and reduction process, the mixed material is placed in a reducing atmosphere at 1100-1200° C., the metallic zinc oxide is reduced to metallic zinc vapor, and the metallic zinc vapor combines with oxygen to generate secondary zinc oxide. The roasted slag is crushed by high-pressure water flow and immersed in the slag cooling process, and is screened after cooling to magnetically select slag with a particle size of less than 6 mm.

[0019] Preferably, in the flue gas desulfurization and zinc collection process and the flue gas cooling waste heat recovery process, the roasting flue gas is subjected to gravity sedimentation and then waste heat recovery, the flue gas is cooled to 180°C and then dust is collected, and the zinc-containing dust is collected and the remaining flue gas is subjected to desulfurization treatment.

[0020] This application adopts graded water washing evaporation and rotary kiln fire reduction fume enrichment technology, uses graded water washing evaporation to recover alkali metals and dechlorination, uses rotary kiln to remove zinc and extract iron, lead, zinc, alkali metals, and chloride salts are reduced and volatilized in the flue gas, and the high-temperature flue gas is discharged after gravity settling chamber, waste heat boiler sedimentation, surface cooling, bag zinc collection, and tail gas desulfurization. The iron in the dust is reduced and enriched in the rotary kiln to form iron-containing kiln slag, and sintering, blast furnace, and steelmaking raw materials with an iron content of more than 50% are obtained. The by-product secondary zinc oxide can be directly sold after collection and packaging.

[0021] The present invention also provides a system used in the dust removal ash solid waste resource utilization method, including: a raw material pre-washing and filtration system, a potassium chloride leaching and evaporation system, a raw material storage system, a premixing system, a batching system, a mixing system, a roasting and reduction system, a slag cooling system, a flue gas cooling waste heat recovery system and a flue gas desulfurization and zinc collection system;

[0022] The raw material pre-water washing filter press system comprises at least two sets of three-stage water washing tanks, a three-stage water washing filter press and a three-stage water washing filter press pump;

[0023] The mixing system includes a mixing chamber, which is a fully sealed steel structure;

[0024] The roasting reduction system includes a reduction rotary kiln. After the materials are mixed in the mixing system, they are conveyed to the upper feed port of the reduction rotary kiln through a belt and flow into the tail of the reduction rotary kiln. The inflowing materials rotate in the rotary kiln and flow from the tail of the kiln to the head of the rotary kiln.

[0025] The flue gas cooling waste heat recovery system and the flue gas desulfurization zinc recovery system include a settling chamber, a waste heat boiler and a dust collector. One end of the settling chamber is connected to the reduction rotary kiln, the other end of the settling chamber is connected to the waste heat boiler, and the other end of the waste heat boiler is connected to the dust collector.

[0026] At present, in the process of resource utilization of dust ash solid waste, in order to control the uniform moisture content of the material, the material is humidified in the premixing process and the batching process, and the humidification method is to humidify directly during the transportation of the material. This humidification method is easy to humidify the material on the upper layer of the conveyor belt, while the material at the bottom layer cannot fully and effectively contact the moisture, resulting in inconsistent humidity of the whole material, which is easy to affect the humidification effect and is not conducive to the subsequent operation of the rotary kiln. Therefore, the present invention makes an improvement on this, and a mixing process is added after the premixing process and the batching process, and the mixing system used in the mixing process includes a mixing chamber.

[0027] Preferably, the mixing chamber is provided with a plurality of feeding pipes for conveying materials;

[0028] There are two stirring structures, which are distributed on both sides of the mixing chamber and are assembled with the driving structure;

[0029] A support frame, which is fixedly installed above the mixing chamber and is used for assembling the driving structure thereon;

[0030] A humidifying structure, which is arranged in the stirring structure and connected to an external water supply pipeline;

[0031] The humidification structure includes a humidification tube, a circulation tube fixed on the humidification tube, and a corrugated hose connected to the outer end of the circulation tube, wherein a humidification nozzle communicating with the inside of the humidification tube is provided at one end of the corrugated hose, and a telescopic rod is commonly connected between the circulation tube and the humidification nozzle;

[0032] The two sides of the top of the humidifying tube are provided with strip grooves, and the mixing drum is slidably assembled with the humidifying tube through the strip grooves;

[0033] One end of the humidifying tube extends to the mounting base and is fixed thereto;

[0034] A spring is sleeved on the surface of the telescopic rod, and one end of the spring is fixedly connected to the outer side of the circulating pipe and is subject to the action force of the spring.

[0035] The present invention realizes that stirring and mixing are performed in a traditional mixing chamber, and synchronous humidification operation can be performed in conjunction with the humidification structure by setting up a stirring structure and a humidification structure, so as to form a dynamic humidification effect and make the material humidification effect more uniform.

[0036] Preferably, the stirring structure comprises a stirring drum and a stirring blade connected to the surface of the stirring drum, the interior of the stirring drum has a receiving cavity for assembling the humidifying structure inside the receiving cavity, and the humidifying nozzle contacts the inner wall of the stirring drum in a natural state;

[0037] A protruding groove is provided at a position corresponding to the humidifying nozzle of the mixing drum, and an inclined guide groove is provided on the bottom wall of the protruding groove, wherein a sealing ring fixed to the humidifying pipe is provided above the protruding groove;

[0038] The bottom wall of the mixing drum is slidably equipped with a mounting seat along the length direction, and the mounting seat is movably assembled with the bottom wall of the mixing chamber through a bearing.

[0039] The mixing chamber of the present invention is controlled by the driving structure to extend and insert the humidifying nozzle into the mixing drum, thereby ensuring the blocking protection of the humidifying nozzle in the process without humidification, and improving its practicality in actual use.

[0040] Preferably, the driving structure comprises a gear 1 and a gear 2 respectively fixed to the surfaces of the two mixing drums, the outer side of the gear 1 is meshed with a transmission wheel 1, the outer side of the gear 2 is meshed with a transmission wheel 2, and the transmission wheel 1 and the transmission wheel 2 are meshed with each other;

[0041] A driving wheel is also meshed on the other side of the gear 1, and a servo motor is fixed on the driving wheel;

[0042] The bottoms of the transmission wheel 1, the transmission wheel 2 and the driving wheel are movably equipped with a support plate, and the support plate is slidably arranged on the side wall of the support frame.

[0043] Preferably, the side wall of the support frame is also slidably provided with an adjustment plate, hydraulic push rods connected to the top wall of the support frame are installed on both sides of the top of the adjustment plate, guide telescopic rods fixed to the support plate are installed at the four corners of the bottom wall of the adjustment plate, and the servo motor is installed on one of the guide telescopic rods.

[0044] Preferably, the output end of the water supply pipe is connected to a shunt pipe, the ends of the two shunt pipes are fixedly connected to water supply ends, and a water supply valve seat matching the water supply end is formed at the position of the humidifying pipe corresponding to the water supply end. After the water supply end is inserted into the water supply valve seat, a water supply input to the inside of the humidifying pipe can be formed.

[0045] The present invention realizes that when the hydraulic push rod is started to drive the adjustment plate to drive the humidification structure to move downward, the water delivery end and the water delivery valve seat are correspondingly connected to form a water supply connection. At the same time, the downward movement of the adjustment plate will cause the mixing drum to slide relative to the humidification pipe, so that the humidification nozzle pops out.

[0046] With multiple humidifying nozzles and position settings, it is ensured that humidification operations can be performed at different angles and directions of the material, further improving the humidification effect and efficiency of the material.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] 1. The treatment method of the present invention realizes the large-scale treatment of steel plant waste dust removal ash, effectively solves the problem of dust waste stacking occupying a large amount of land resources, avoids the recycling of zinc-containing dust within the steel enterprise, thereby reducing the accumulation of zinc elements inside the blast furnace, effectively prolonging the service life of the blast furnace, and reducing the maintenance cost and production risk of the enterprise.

[0049] 2. Through the potassium chloride leaching and evaporation process, valuable products such as industrial potassium chloride can be extracted from solid waste, realizing resource recovery and reuse. At the same time, the slag after reduction roasting is crushed, magnetically separated and briquette-pressed to obtain steelmaking raw materials with an iron content of about 50%, further improving the utilization efficiency of resources.

[0050] 3. In the flue gas desulfurization and zinc collection process and the flue gas cooling waste heat recovery process, the present invention performs dust collection and desulfurization treatment on the roasting flue gas, ensuring that the flue gas is discharged in compliance with the standards, and at the same time collects secondary zinc oxide dust; the waste heat of the flue gas and the heat of slag cooling are recovered through the waste heat boiler and used in subsequent processing links such as the potassium chloride leaching and evaporation process, thereby achieving energy conservation and efficient utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 A process flow chart of a method for resource utilization of dust ash solid waste for this application;

[0052] Figure 2 A schematic diagram of the structure of a dust ash solid waste resource utilization system for this application;

[0053] Figure 3 This is a schematic diagram of the structure of the mixing chamber in the mixing system of this application;

[0054] Figure 4 This is a schematic diagram of the stirring structure of the mixing chamber of this application;

[0055] Figure 5 This is a schematic diagram of the initial form of the driving structure of the mixing chamber of the present application;

[0056] Figure 6 For this application Figure 5 The enlarged structural diagram at A in the middle;

[0057] Figure 7 This is a schematic diagram of the mounting structure of the mixing chamber of this application;

[0058] Figure 8 This is a schematic diagram of the support frame structure of the mixing chamber of this application;

[0059] Fig. 9 This is a schematic diagram of the second form structure of the mixing chamber driving structure of the present application;

[0060] Fig.10 For this application Fig. 9 The enlarged structural diagram at B in the middle;

[0061] Indicated in the figure:

[0062] 1. Mixing chamber; 2. Stirring structure; 3. Driving structure; 4. Support frame; 5. Humidification structure;

[0063] 11. Feed pipe;

[0064] 21. Mixing drum; 22. Mixing blade; 23. Accommodating chamber; 24. Extending groove; 25. Inclined guide groove; 26. Sealing ring; 27. Mounting seat;

[0065] 31. Gear 1; 32. Gear 2; 33. Transmission wheel 1; 34. Transmission wheel 2; 35. Driving wheel; 36. Servo motor; 37. Support plate;

[0066] 41. Adjustment plate; 42. Hydraulic push rod; 43. Guide telescopic rod;

[0067] 51. Humidification tube; 52. Circulation tube; 53. Corrugated hose; 54. Humidification nozzle; 55. Telescopic rod; 56. Spring; 57. Strip groove;

[0068] 510, diverter pipe; 511, water delivery end; 512, water delivery valve seat. DETAILED DESCRIPTION

[0069] To make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be described clearly and completely in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0070] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents some embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0071] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features and technical solutions in the embodiments may be combined with each other.

[0072] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0073] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the invention product is usually placed when in use, or the orientation or positional relationship commonly understood by those skilled in the art. Such terms are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance. Example 1

[0074] See also Figure 1 , which is a process flow chart of a method for resource utilization of dust ash solid waste in this application.

[0075] The present invention provides a method for resource utilization of dust ash solid waste, including a raw material pre-washing and filtration process, a potassium chloride leaching and evaporation process, a raw material storage process, a premixing process, a material supplying and batching process, a mixing process, a roasting and reduction process, a slag cooling process, a flue gas cooling waste heat recovery process and a flue gas desulfurization and zinc recovery process;

[0076] Raw material pre-washing and filtration process: including the multi-stage washing process of machine head ash and the multi-stage washing process of blast furnace bag ash;

[0077] In the multi-stage washing process of blast furnace bag ash, the blast furnace sludge is first washed three times with kiln slag cooling water, and the slurry after washing enters the filter press for mud and water separation. The filtrate after separation returns to the secondary washing, and the filtrate of the secondary washing slurry after separation by the filter press returns to the primary washing. The filtrate of the primary washing slurry is treated as the final filtrate. After the bag ash is washed three times, the chloride ion content is reduced to less than 1% after the filter press removes most of the water. After mixing with other materials, it is used as a raw material for the rotary kiln. The filtrate of the primary washing slurry in the multi-stage washing process of blast furnace bag ash is used in the multi-stage washing process of machine head ash to perform secondary washing on the machine head ash; the filtrate obtained in the multi-stage washing process of machine head ash enters the subsequent potassium chloride leaching and evaporation process.

[0078] Potassium chloride soaking and evaporation process: The filtrate obtained in the head ash multi-stage water washing process is pretreated and initially concentrated, and then evaporated, concentrated and fractionated and crystallized to obtain the product industrial potassium chloride and the by-products sodium chloride and sodium sulfate.

[0079] The filtrate after cleaning is pre-treated and concentrated to reduce the water content, and then enters the evaporation system for crystallization and salt separation. The product is industrial potassium chloride, which can be sold as a raw material for potash fertilizer. The evaporation condensate is combined with the water produced by the concentration system and then sent out for reuse.

[0080] Raw material storage process: storing the filter residue, gravity ash and steelmaking ash from the multi-stage water washing process of blast furnace bag ash;

[0081] Premixing process: premixing filter residues, including salt extraction filter press mud, blast furnace sludge and converter sludge, to obtain a premix;

[0082] The batching process, mixing process and roasting and reduction process: add reducing agent and heating agent (cyclone ash, gravity ash) into the premix, control the moisture content to be uniform, mix well, and then carry out reduction roasting on the materials;

[0083] Slag cooling process: Cool the material obtained by reduction roasting to obtain iron-containing slag, crush the iron-containing slag, magnetically separate and briquette to obtain steelmaking raw materials with an iron content of about 50%;

[0084] In the roasting reduction process, the mixed material is placed in a reducing atmosphere at 1100-1200°C, and the metallic zinc oxide is reduced to metallic zinc vapor. The metallic zinc vapor combines with oxygen to form secondary zinc oxide. The roasted slag is crushed by high-pressure water flow and immersed in the slag cooling process. After cooling, it is screened and the slag with a particle size of less than 6 mm is magnetically selected.

[0085] Flue gas cooling waste heat recovery process: The heat obtained from slag cooling and the waste heat from flue gas cooling are recovered and used in the potassium chloride leaching and evaporation process;

[0086] Flue gas desulfurization and zinc collection process: The flue gas generated by the reduction roasting of the material is collected after sedimentation to obtain secondary zinc oxide, and the remaining gas is discharged after desulfurization and denitrification.

[0087] The roasting flue gas undergoes gravity sedimentation, and the larger particles (usually with a diameter greater than 100μm) in the airflow are separated from the slowly flowing airflow by gravity and deposited in the dust collector. The dust containing ZnO and tiny particles continues to flow with the gas and is cooled. When the flue gas is cooled to 180℃, dust collection is carried out, and the zinc-containing dust is collected. The remaining flue gas is desulfurized.

[0088] Raw materials such as dust removal ash and dust are sent to the raw material storage warehouse for storage, and the salt extraction filter press mud, blast furnace sludge, converter sludge, etc. are premixed to control the moisture uniformity. The reducing agent and heating agent (cyclone ash, gravity ash) are added after mixing and sent to the roasting reduction system for reduction roasting. Chloride ions, sulfur and zinc oxide are vaporized and discharged from the kiln with the flue gas, and secondary zinc oxide is collected. The kiln slag is cooled to obtain iron-containing kiln slag, and the sintering, blast furnace and steelmaking raw materials with an iron content of about 50% are obtained.

[0089] This application adopts graded water washing evaporation and rotary kiln fire reduction fume enrichment technology, uses graded water washing evaporation to recover alkali metals and dechlorination, uses rotary kiln to remove zinc and extract iron, lead, zinc, alkali metals, and chloride salts are reduced and volatilized in the flue gas, and the high-temperature flue gas is discharged after gravity settling chamber, waste heat boiler sedimentation, surface cooling, bag zinc collection, and tail gas desulfurization. The iron in the dust is reduced and enriched in the rotary kiln to form iron-containing kiln slag, and the sintering, blast furnace, and steelmaking raw materials with an iron content of more than 50% are obtained. The by-product secondary zinc oxide can be directly sold after collection and packaging. Example 2

[0090] See also Figure 2 , which is a process flow chart of a dust ash solid waste resource utilization system applied for.

[0091] A dust ash solid waste resource utilization system used in a dust ash solid waste resource utilization method includes: a raw material pre-water washing and filtration system, a potassium chloride leaching and evaporation system, a raw material storage system, a premixing system, a material supply and batching system, a mixing system, a roasting and reduction system, a slag cooling system, a flue gas cooling waste heat recovery system and a flue gas desulfurization and zinc recovery system.

[0092] The raw material pre-washing filter press system includes two sets of three-stage washing tanks, three-stage washing filter presses and three-stage washing filter press pumps, which respectively process head ash and blast furnace bag ash, and perform multi-stage washing and slag-liquid separation on them.

[0093] In the potassium chloride soaking and evaporation system, the machine head ash undergoes multi-stage water washing, and the filtrate after washing is pre-treated and concentrated to reduce the water volume, and then enters the evaporation system for crystallization and salt separation. The product is industrial potassium chloride, which can be sold as a raw material for potassium fertilizer.

[0094] The raw material storage system, premixing system and batching system are used for raw material storage and raw material preparation production. Raw materials such as dust removal ash and dust are sent to the raw material storage warehouse for storage, and salt extraction filter press mud, blast furnace sludge, converter sludge, etc. are premixed to control the uniformity of moisture, and the reducing agent and heating agent (cyclone ash, gravity ash) are added through batching. The key control circuits of batching are uniformly installed in the central control room and have automatic control functions.

[0095] The mixing system includes a mixing chamber 1, which is a fully sealed steel structure. In order to improve the fluidity, adhesion, particle size uniformity and air permeability of the material in the kiln, alleviate the ring formation of the rotary kiln and reduce the dust content of the flue gas, a humidifier mixing scheme is designed. The purpose of mixing is to add water and mix the mixture completely.

[0096] The roasting reduction system includes a reduction rotary kiln. After the materials are mixed in the mixing system, they are conveyed to the upper feed port of the reduction rotary kiln through a belt and flow into the tail of the reduction rotary kiln. The inflowing materials rotate in the rotary kiln and flow from the tail of the kiln to the head of the rotary kiln. During normal operation, the main drive motor transmits power to the open gear device through the main reducer to drive the rotary kiln. The materials enter the kiln from the tail of the kiln (the high end of the cylinder) for calcination. Due to the tilting and slow rotation of the cylinder, the materials roll in the circumferential direction and move in the axial direction (from the high end to the low end), continuing to complete the process of decomposition and sintering. Finally, the clinker falls into the kiln slag water quenching pool through the kiln head cover unloading chute.

[0097] The slag cooling system adopts water cooling. The slag is discharged from the kiln head, crushed by the high-speed water flow with pressure from the slag flushing pump, and then enters the slag pool through the slag flushing ditch for immersion and cooling. The cooled slag is transported to the screening transfer warehouse by a 10t bridge crane through a grab bucket. A grid is set on the top of the warehouse to pre-clear large pieces larger than 100mm. The water-quenched slag smaller than 100mm falls into the magnetic separation vibration screening machine for screening. The screened material larger than 6mm enters the temporary storage bin for the screened material, and the water-quenched slag under the screen less than 6mm enters the temporary storage bin for the screened material, so as to obtain sintering, blast furnace or steelmaking raw materials with an iron content of more than 50%.

[0098] The flue gas cooling waste heat recovery system includes a waste heat boiler and a main surface cooler. A membrane wall structure waste heat boiler is installed at the tail of the rotary kiln to utilize the waste heat of the flue gas. The waste heat boiler body is installed after the settling chamber at the tail of the rotary kiln and before the main dust collector. The main surface cooler is set on the waste heat boiler body. Its main function is to adjust the flue gas temperature so that the high-temperature furnace gas of 550±100℃ at the outlet of the rotary kiln is cooled to 250℃ through the waste heat boiler body.

[0099] The flue gas desulfurization and zinc collection system includes a main dust collector, which is arranged at the outlet of the main surface cooler to collect secondary zinc oxide dust. The remaining flue gas is discharged after being desulfurized by a desulfurization tower. Example 3

[0100] On the basis of Example 2, the mixing chamber 1 of the mixing system is improved. Figures 3 to 10 .

[0101] like Figure 3 As shown, a mixing chamber 1 is provided with a plurality of feed pipes 11 for conveying raw materials and auxiliary materials; the mixing chamber 1 comprises a stirring structure 2, a support frame 4 and a humidifying structure 5; the stirring structure 2 has two stirring structures 2, which are distributed on both sides of the mixing chamber 1 and are assembled with the driving structure 3 for transmission; the support frame 4 is fixedly installed above the mixing chamber 1 for assembling the driving structure 3 thereon; the humidifying structure 5 is arranged in the stirring structure 2 and is connected to an external water supply pipeline.

[0102] like Figure 4 ,5 , 6 and 7, the stirring structure 2 includes a stirring drum 21 and a stirring blade 22 connected to the surface of the stirring drum 21; the interior of the stirring drum 21 has a receiving chamber 23 for assembling the humidifying structure 5 therein. The bottom wall of the stirring drum 21 is slidably mounted with a mounting seat 27 along the length direction, and the mounting seat 27 is movably assembled with the bottom wall of the mixing chamber 1 through a bearing. When the stirring drum 21 is subjected to an external force, it can slide relative to the surface of the mounting seat 27 along its length direction, as shown in FIG. Figure 7 .

[0103] refer to Figure 5 The output end of the water supply pipeline is connected to a shunt pipe 510, and the ends of the two shunt pipes 510 are fixedly connected to water delivery ends 511, and a water delivery valve seat 512 matching with it is formed at the position of the humidifying tube 51 corresponding to the water delivery end 511. After the water delivery end 511 is inserted into the water delivery valve seat 512, water supply input to the inside of the humidifying tube 51 can be formed.

[0104] refer to Figure 6 The humidification structure 5 includes a humidification tube 51, a circulation tube 52 fixed on the humidification tube 51, and a corrugated hose 53 connected to the outer end of the circulation tube 52, wherein a humidification nozzle 54 communicating with the inside of the humidification tube 51 is provided at one end of the corrugated hose 53, and a telescopic rod 55 is commonly connected between the circulation tube 52 and the humidification nozzle 54, and one end of the humidification tube 51 extends to the mounting seat 27 and is fixed thereto;

[0105] A spring 56 is sleeved on the surface of the telescopic rod 55, and one end of the spring 56 is fixedly connected to the outer side of the circulation tube 52. Under the action of the spring 56, the humidifying nozzle 54 naturally contacts the inner wall of the mixing drum 21.

[0106] An extension groove 24 is provided at a position of the mixing drum 21 corresponding to the humidifying nozzle 54 , and an inclined guide groove 25 is provided on the bottom wall of the extension groove 24 . A sealing ring 26 fixed to the humidifying tube 51 is provided above the extension groove 24 .

[0107] like Figure 8 As shown, strip grooves 57 are provided on both sides of the top of the humidifying tube 51, and the mixing drum 21 is slidably assembled with the humidifying tube 51 through the strip grooves 57. Under the action of the strip grooves 57, the mixing drum 21 can slide along the height direction of the humidifying tube 51, and the mixing drum 21 can also synchronously drive the humidifying tube 51 to rotate;

[0108] The driving structure 3 includes a gear 1 31 and a gear 2 32 respectively fixed to the surfaces of the two mixing drums 21, and the outer sides of the gear 1 31 and the gear 2 32 are respectively meshed with a transmission wheel 1 33 and a transmission wheel 2 34, and the transmission wheel 1 33 and the transmission wheel 2 34 are meshed with each other;

[0109] A driving wheel 35 is also meshed on the other side of the gear 1 31, and a servo motor 36 is fixed on the driving wheel 35;

[0110] The bottoms of the transmission wheel 1 33 , the transmission wheel 2 34 and the driving wheel 35 are movably equipped with a support plate 37 , and the support plate 37 is slidably arranged on the side wall of the support frame 4 .

[0111] The side wall of the support frame 4 is also slidably provided with an adjustment plate 41, and hydraulic push rods 42 connected to the top wall of the support frame 4 are installed on both sides of the top of the adjustment plate 41, and guide telescopic rods 43 fixed to the support plate 37 are installed at the four corners of the bottom wall of the adjustment plate 41, and the servo motor 36 is installed on one of the guide telescopic rods 43.

[0112] like Figure 5 , Figure 6 , Figure 7 and Figure 8 As shown, at this time, it is in the non-humidified state. When the material needs to be humidified, the hydraulic push rod 42 is started so that its output end drives the adjustment plate 41 to slide along the height direction of the support frame 4, so that the support frame 4 drives the driving structure 3 thereon to move downward. During the process of the driving structure 3 as a whole and the support plate 37 moving downward, the support plate 37 will drive the mixing drum 21 fixedly connected thereto to move downward synchronously;

[0113] When the mixing drum 21 moves downward, the multiple extension grooves 24 on it will also move downward. After the extension grooves 24 move downward to the position corresponding to the position of the humidifying nozzle 54, the humidifying nozzle 54 will pop out of the extension grooves 24 under the force of the spring 56. In addition, during the downward movement of the adjustment plate 41, the water delivery end 511 at the end of the shunt pipe 510 on the adjustment plate 41 will also be engaged with the corresponding water delivery valve seat 512.

[0114] When the humidifying nozzle 54 pops out of the extension slot 24, the water delivery end 511 is just engaged with the corresponding water delivery valve seat 512. At this time, the diverter pipe 510 is supplied with water through the external water supply pipeline, and the materials in the mixing chamber 1 can be humidified synchronously through the multiple humidifying nozzles 54.

[0115] When humidification is completed, the adjustment plate 41 is slid and reset by the action of the hydraulic push rod 42. During the reset process, the humidification nozzle 54 is subjected to the force of the inclined guide groove 25 and will slide sideways. Finally, the humidification nozzle 54 will slide on the inner wall of the mixing drum 21 and form a conflict with the inner wall. When the mixing drum 21 slides upward to the position corresponding to the blocking ring 26, the blocking ring 26 forms a blockage on the extension groove 24. At this time, the water delivery end 511 is also separated from the water delivery valve seat 512.

[0116] At this time, the servo motor 36 can be started so that its output end drives the driving wheel 35 to rotate. The rotation of the driving wheel 35 will drive the synchronous rotation of the gear 1 31, the gear 2 32, the transmission wheel 1 33 and the transmission wheel 2 34, so that the mixing drum 21 and the stirring blades 22 thereon can be driven to rotate, thereby forming a stirring operation for the material inside the mixing chamber 1. Since the mixing drum 21 and the humidifying tube 51 are slidably assembled, when the mixing drum 21 rotates, the humidifying tube 51 thereon will also rotate synchronously due to the action of the strip groove 57, thereby ensuring the blocking effect between the extension groove 24 and the blocking ring 26, see Fig. 9 and Fig.10 .

[0117] This embodiment realizes that the stirring structure 2 and the humidifying structure 5 are provided to achieve a synchronous humidification operation in the traditional mixing chamber while stirring and mixing, so as to form a dynamic humidification effect and make the material humidification effect more uniform;

[0118] At the same time, the driving structure 3 can control the extension and insertion of the humidifying nozzle 54 in the mixing drum 21, thereby ensuring the blocking protection of the humidifying nozzle 54 when no humidification is required, thereby improving its practicality in actual use;

[0119] By means of the driving structure 3, when the hydraulic push rod 42 is started to drive the adjusting plate 41 to move the humidifying structure 5 downward, the water delivery end 511 and the water delivery valve seat 512 are connected to each other to form a water supply connection. Meanwhile, the downward movement of the adjusting plate 41 will cause the mixing drum 21 to slide relative to the humidifying tube 51, so that the humidifying nozzle 54 pops out.

[0120] With the arrangement of multiple humidifying nozzles 54 and their positions, it is ensured that the humidification operation can be performed at different angles and directions of the material, further improving the humidification effect and humidification efficiency of the material;

[0121] The two relatively rotating stirring blades 22 further enhance the stirring effect on the material inside the mixing chamber 1, thereby further enhancing the mixing effect, and thus will not affect the humidification operation, so that the system integrates stirring and humidification, simplifying the overall structural design.

[0122] The above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Although the present invention has been described in detail with reference to the above embodiments, the present invention is not limited to the above specific implementation methods. Therefore, any modification or equivalent replacement of the present invention; and all technical solutions and improvements thereof that do not depart from the spirit and scope of the invention are included in the scope of the claims of the present invention.

Claims

1. A method for resource utilization of dust ash solid waste, characterized in that: It includes alkali metal recovery process, iron recovery process and zinc recovery process; The alkali metal recovery process includes the raw material pre-water washing and filtration process and the potassium chloride leaching and evaporation process in sequence; the iron recovery process includes the raw material storage process, the premixing process, the material supply process, the mixing process, the roasting and reduction process, and the slag cooling process in sequence; the zinc recovery process includes the flue gas cooling waste heat recovery process and the flue gas desulfurization zinc recovery process in sequence; Raw material pre-washing and filtration process: including the multi-stage washing process of machine head ash and the multi-stage washing process of blast furnace bag ash; In the multi-stage washing process of blast furnace bag ash, the blast furnace sludge is washed three times with kiln slag cooling water, the slurry after washing enters the filter press for mud and water separation, the filtrate after separation returns to the secondary washing, the filtrate of the secondary washing slurry after separation by the filter press returns to the primary washing, and the filtrate of the primary washing slurry is used as the final filtrate for the multi-stage washing process of the head ash; The filtrate of the primary washing slurry in the multi-stage washing process of blast furnace bag ash is used in the multi-stage washing process of machine head ash to perform secondary washing on the machine head ash; The filtrate obtained from the head ash multi-stage water washing process enters the potassium chloride leaching and evaporation process; Potassium chloride washing and evaporation process: The filtrate obtained in the head ash multi-stage water washing process is pre-treated and initially concentrated, and then evaporated, concentrated and fractionated and crystallized to obtain the product industrial potassium chloride and the by-products sodium chloride and sodium sulfate; Raw material storage process: storing the filter residue, gravity ash and steelmaking ash from the multi-stage water washing process of blast furnace bag ash; Premixing process: premixing filter residues, including salt extraction filter press mud, blast furnace sludge and converter sludge, to obtain a premix; The batching process, mixing process and roasting reduction process are as follows: the stored gravity ash is added to the premix as a reducing agent and a heating agent, the moisture content is controlled to be uniform, and after mixing, the material is subjected to reduction roasting; In the roasting reduction process, the mixed material is placed in a reducing atmosphere at 1100-1200°C, and the metal zinc oxide is reduced to metal zinc vapor, which is combined with oxygen to form secondary zinc oxide. The roasted slag is crushed by high-pressure water flow and immersed in the slag cooling process, and then screened after cooling to separate the slag with a particle size of less than 6 mm and the slag with a particle size of more than 6 mm. Slag cooling process: Cool the material obtained by reduction roasting to obtain iron-containing slag, crush, magnetically separate and briquette the iron-containing slag to obtain steelmaking raw materials with an average iron content of 50%; Flue gas cooling waste heat recovery process: The heat obtained from slag cooling and the waste heat from flue gas cooling are recovered and used in the potassium chloride leaching and evaporation process; The flue gas desulfurization and zinc collection process is to collect the flue gas generated by the reduction roasting of materials after sedimentation to obtain the product of secondary zinc oxide, and the remaining gas is discharged after desulfurization and denitrification; In the flue gas desulfurization and zinc collection process and the flue gas cooling waste heat recovery process, the roasting flue gas undergoes gravity sedimentation and then waste heat recovery. The flue gas is cooled to 180°C and then dust is collected. The zinc-containing dust is collected and the remaining flue gas is desulfurized.

2. The dust ash solid waste resource utilization system used in the dust ash solid waste resource utilization method according to claim 1 is characterized in that: include: The raw material pre-washing and filtration system, potassium chloride leaching and evaporation system, raw material storage system, premixing system, material supply and batching system, mixing system, roasting and reduction system, slag cooling system, flue gas cooling waste heat recovery system and flue gas desulfurization and zinc collection system are connected in sequence; The raw material pre-water washing filter press system comprises at least two sets of three-stage water washing tanks, a three-stage water washing filter press and a three-stage water washing filter press pump; the mixing system comprises a mixing chamber (1), and the mixing chamber (1) is a fully sealed steel structure; The roasting reduction system includes a reduction rotary kiln. After the materials are mixed in the mixing system, they are conveyed to the upper feed port of the reduction rotary kiln through a belt and flow into the tail of the reduction rotary kiln. The inflowing materials rotate in the rotary kiln and flow from the tail of the kiln to the head of the rotary kiln. The flue gas cooling waste heat recovery system and the flue gas desulfurization zinc recovery system include a settling chamber, a waste heat boiler and a dust collector. One end of the settling chamber is connected to the reduction rotary kiln, the other end of the settling chamber is connected to the waste heat boiler, and the other end of the waste heat boiler is connected to the dust collector.

3. A dust ash solid waste resource utilization system according to claim 2, characterized in that: The mixing chamber (1) of the mixing system has a plurality of feed pipes (11) distributed thereon for conveying materials; A stirring structure (2), which has two stirring structures (2), which are distributed on both sides of the mixing chamber (1) and are transmission-assembled with the driving structure (3); A support frame (4) fixedly mounted above the mixing chamber (1) for assembling the driving structure (3) thereon; A humidifying structure (5), which is arranged in the stirring structure (2) and connected to an external water supply pipeline; The humidifying structure (5) comprises a humidifying tube (51), a circulation tube (52) fixed on the humidifying tube (51), and a corrugated hose (53) connected to the outer end of the circulation tube (52), wherein a humidifying nozzle (54) communicating with the interior of the humidifying tube (51) is provided at one end of the corrugated hose (53), and a telescopic rod (55) is commonly connected between the circulation tube (52) and the humidifying nozzle (54); Strip grooves (57) are provided on both sides of the top of the humidifying tube (51), and the mixing drum (21) is slidably assembled with the humidifying tube (51) through the strip grooves (57); One end of the humidifying tube (51) extends onto the mounting seat (27) and is fixed thereto; A spring (56) is sleeved on the surface of the telescopic rod (55), and one end of the spring (56) is fixedly connected to the outside of the circulating pipe (52) and is subject to the action of the spring (56).

4. The dust ash solid waste resource utilization system according to claim 3 is characterized in that: The stirring structure (2) comprises a stirring drum (21) and a stirring blade (22) connected to the surface of the stirring drum (21); the stirring drum (21) has an interior containing a cavity (23) for assembling the humidifying structure (5) inside the accommodating cavity (23); and the humidifying nozzle (54) contacts the inner wall of the stirring drum (21) in a natural state; A protruding groove (24) is provided at a position of the mixing drum (21) corresponding to the humidifying nozzle (54), and a bevel guide groove (25) is provided on the bottom wall of the protruding groove (24), wherein a sealing ring (26) fixed to the humidifying tube (51) is provided above the protruding groove (24); A mounting seat (27) is slidably mounted on the bottom wall of the mixing drum (21) along the length direction, and the mounting seat (27) is movably mounted on the bottom wall of the mixing chamber (1) via a bearing.

5. The dust ash solid waste recycling system according to claim 4 is characterized in that: The driving structure (3) comprises a gear 1 (31) and a gear 2 (32) respectively fixed to the surfaces of the two mixing drums (21); a transmission wheel 1 (33) is meshed on the outer side of the gear 1 (31); a transmission wheel 2 (34) is meshed on the outer side of the gear 2 (32); and the transmission wheel 1 (33) and the transmission wheel 2 (34) are meshed with each other; A driving wheel (35) is also meshed with the other side of the gear 1 (31), and a servo motor (36) is fixed on the driving wheel (35); The bottoms of the transmission wheel 1 (33), the transmission wheel 2 (34) and the driving wheel (35) are movably equipped with a support plate (37), and the support plate (37) is slidably arranged on the side wall of the support frame (4).

6. The dust ash solid waste recycling system according to claim 5 is characterized in that: The side wall of the support frame (4) is also slidably provided with an adjustment plate (41), hydraulic push rods (42) connected to the top wall of the support frame (4) are installed on both sides of the top of the adjustment plate (41), and guide telescopic rods fixed to the support plate (37) are installed at the four corners of the bottom wall of the adjustment plate (41), and the servo motor (36) is installed on one of the guide telescopic rods (43).

7. The dust ash solid waste recycling system according to claim 3 is characterized in that: The output end of the water supply pipeline is connected to a shunt pipe (510), the ends of the two shunt pipes (510) are fixedly connected to water delivery ends (511), and a water delivery valve seat (512) matching with the water delivery end (511) is formed at a position of the humidifying pipe (51) corresponding to the water delivery end (511), and the water delivery end (511) can form a water supply input to the inside of the humidifying pipe (51) after being inserted into the water delivery valve seat (512).

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