Comprehensive recovery system for valuable elements in metallurgical dust and mud

Abstract

The utility model discloses a comprehensive recovery system for valuable elements in metallurgical dust and mud, which solves the problems that in the prior art, blast furnace cloth bag ash and sintering machine head ash are difficult to directly recycle, the comprehensive utilization value is low, secondary pollution is generated in the treatment process and the like. Separation, recovery and utilization of valuable elements in the blast furnace cloth bag ash and the sintering machine head ash are achieved, the process is flexible, the raw material adaptability is high, secondary solid waste is not generated, and waste water is not discharged.

Description

Technical Field

[0001] The utility model relates to the technical field of comprehensive utilization of solid wastes, and relates to a comprehensive recovery system for valuable elements in metallurgical dust and mud, in particular to a comprehensive recovery system for valuable elements in metallurgical dust and mud in blast furnace bag ash and sintering machine head ash. Background Art

[0002] In recent years, my country's steel enterprises have produced about 100 million tons of metallurgical dust and sludge each year. The composition of these metallurgical dust and sludge is complex. In addition to the valuable element iron, it also contains valuable elements such as zinc, lead, potassium, sodium, chlorine, gold, and silver. From the perspective of in-plant circulation, metallurgical dust and sludge are directly recycled and returned to production for sintering, rotary hearth furnaces, blast furnaces, etc. The above process makes sintering, rotary hearth furnaces, and blast furnaces face the severe test of cyclic enrichment of harmful elements. According to the survey, the zinc content in the blast furnace bag ash reaches 2% to 15%, and the lead content in the sintering machine head ash reaches 1% to 20%. They are very important secondary resources containing zinc and lead. Their resource utilization not only meets environmental protection requirements, but also can generate considerable economic benefits.

[0003] At present, the comprehensive recovery plan for blast furnace bag ash and sintering machine head ash in steel mills is mainly a wet method and pyrolysis method. The wet method is mainly based on water washing. The two types of ashes are generally washed separately. The water washing production line is equipped with a potassium salt recovery system. The washed bag ash enters the rotary hearth furnace / rotary kiln to recover zinc, and the washed machine head ash is reused for sintering. The above process goal is to remove potassium, sodium, and chlorine elements from metallurgical dust and mud to achieve their recycling. Sintering machine head ash has slightly different contents of main components due to different production points. It is directly and simply washed and reused in the sintering system, resulting in its low value, and it is easy to generate secondary pollution during the disposal process. The cost of recovering zinc powder from blast furnace bag ash through water washing, rotary hearth furnace / rotary kiln and other processes is relatively high, and the quality of zinc powder needs to be further improved to improve the economy of the process.

[0004] The document with patent number CN202110082273.5 discloses a method for the coordinated treatment of blast furnace bag dust removal ash and sintering machine head dust removal ash, and adopts a combined water washing process to realize the resource utilization of Fe, Zn, K, Na, Cl and other elements in blast furnace bag dust removal ash and sintering machine head dust removal ash. The document with patent number CN202110864057.6 discloses a method for the comprehensive recovery of valuable elements by combining blast furnace bag dust and sintering machine head ash, and comprehensively recovers Zn, Fe, Ag and other elements through magnetic separation and flotation processes. The sintering machine head ash in the above-mentioned documents has not been graded for utilization, but simply washed and then sintered. Its non-ferrous metals and precious metals are not recovered, the resource value is low, and the value of system by-products is not high, which is severely restricted when sold to the downstream market. Utility Model Content

[0005] The utility model aims to provide a comprehensive recovery system for valuable elements in metallurgical dust and sludge, so as to solve the problems in the prior art of difficulty in directly reusing blast furnace bag ash and sintering machine head ash, low comprehensive utilization value, secondary pollution generated during disposal, etc., and the blast furnace bag ash and sintering machine head ash are graded for utilization, so as to realize the separation, recovery and utilization of valuable elements in blast furnace bag ash and sintering machine head ash, with flexible process, strong adaptability of raw materials, no secondary solid waste generation, and no wastewater discharge.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] The utility model provides a comprehensive recovery system of valuable elements in metallurgical dust and mud, including a water washing pretreatment system and a valuable element recovery system;

[0008] The water washing pretreatment system is used to jointly wash blast furnace bag ash and sintering machine head ash; the water washing pretreatment system includes a bag ash water washing and filter pressing module, a first sintering machine head ash water washing and filter pressing module, and a second sintering machine head ash water washing and filter pressing module; the bag ash water washing and filter pressing module is used to wash and filter the blast furnace bag ash to obtain washed bag ash, and the filtrate outlet of the bag ash water washing and filter pressing module is respectively connected to the water inlet of the first sintering machine head ash water washing and filter pressing module and the second sintering machine head ash water washing and filter pressing module; the first sintering machine head ash water washing and filter pressing module uses the filtrate of the bag ash water washing and filter pressing module to wash and filter the one-two electric field sintering machine head ash to obtain washed one-two electric field machine head ash; the second sintering machine head ash water washing and filter pressing module uses the filtrate of the bag ash water washing and filter pressing module to wash and filter the three-four electric field sintering machine head ash to obtain washed three-four electric field machine head ash;

[0009] The valuable element recovery system comprises a three-fourth electric field machine head ash reduction module, a batching module, a reduction roasting kiln, a dust collection system, and a grinding magnetic separation system; the three-fourth electric field machine head ash reduction module is used to reduce and recover lead in the water-washed three-fourth electric field machine head ash, and comprises a first mixer, a side-blowing furnace, a first water quenching tank, a first crushing equipment, a first grinding equipment, and a filter press connected in sequence; the batching module is used to uniformly mix the water-washed one-two electric field machine head ash with the water-washed bag ash, carbon powder, and zinc-containing materials, and the discharge port of the batching module is connected to the reduction roasting kiln through a discharge belt and a chute; the reduction roasting kiln is divided into The reduction roasting kiln comprises a preheating section, a transition section, a reduction section, a cooling section and a discharging section. A stirring paddle for stirring materials is arranged in the reduction roasting kiln, and the rotation direction of the stirring paddle is controlled by a motor. The cooling section of the reduction roasting kiln is provided with a flue gas outlet connected to a dust collecting system. The dust collecting system is used to process the flue gas from the reduction roasting kiln and recover zinc powder. The grinding and magnetic separation system is used to grind, float and magnetically separate the kiln slag from the reduction roasting kiln, and recover carbon powder and iron powder. The grinding and magnetic separation system comprises a water quenching tank, a second crushing equipment, a second grinding equipment, a flotation equipment, a strong magnetic roughing separator and a strong magnetic sweeping separator connected in sequence.

[0010] Further, the bag ash water washing and filter pressing module includes a first water washing device and a first filter press;

[0011] The first sintering machine head ash water washing and filter pressing module comprises a second water washing device, a second filter press, a third water washing device and a third filter press connected in sequence; the water inlet of the second water washing device is connected to the filtrate outlets of the first filter press and the second first filter press; the filtrate outlets of the third water washing device and the third filter press are connected to the water inlet of the second water washing device;

[0012] The second sintering machine head ash water washing and filter pressing module comprises a fourth water washing device, a fourth filter press, a fifth water washing device, and a fifth filter press connected in sequence; the water inlet of the fourth water washing device is connected to the filtrate outlets of the first filter press and the second first filter press; the filtrate outlets of the fifth water washing device and the fifth filter press are connected to the water inlet of the fourth water washing device;

[0013] The filtrate outlets of the second filter press and the fourth filter press are connected to a potassium salt recovery system.

[0014] Furthermore, the potassium salt recovery system includes a flotation device, an impurity removal device, and an evaporation crystallization system which are connected in sequence; the flotation device is connected to the filtrate outlets of the second filter press and the fourth filter press respectively.

[0015] Furthermore, the stirring paddle of the reduction roasting kiln includes a stirring shaft, a base arranged on the stirring shaft and blades arranged on the base; the stirring shaft and the base are made of a nickel-based high-temperature resistant alloy, and the blade sections are made of different alloy materials.

[0016] By adopting the above technical solution, the utility model has the following advantages:

[0017] (1) Improved product value and reduced process energy, investment, operation, maintenance and other costs. The content of K, Na and Cl elements in blast furnace bag ash and sintering machine head ash is relatively high, about 15-50%. When the pyrometallurgical process is used to recover valuable metal elements, it will cause serious blockage of the dust collection system and serious corrosion of the bags. At the same time, due to the high Cl content in the product, its downstream sales market is limited and its value is relatively low. The utility model uses graded water washing according to the content of K, Na and Cl elements in the raw materials, and customizes the water washing plan. The water washing and rinsing liquid can be directly removed from impurities and then evaporated and crystallized, which not only saves water consumption in the water washing process, but also saves investment, operation and maintenance costs of the evaporation process.

[0018] (2) The yield of water-washed products and the separation efficiency of valuable elements are improved. In the traditional water-washing process, the sintering machine head ash slurry is acidic. Due to the high concentration of Cl ions in the rinsing slurry, Au, Ag, etc. are easily coordinated with Cl ions and dissolved in water. When other alkaline agents are used to adjust the pH, elements such as Ca and Fe in the system cannot be effectively separated and enter the filter cake. Therefore, in the process of washing the sintering machine head ash with water, the utility model uses sodium carbonate to adjust the pH, which can make the metals such as Fe, Pb, Au, Ag in the machine head ash enter the filter cake in the form of precipitation, thereby improving the recovery rate of the above valuable elements.

[0019] (3) The powdered material of the utility model is directly put into the furnace, eliminating the drying process, which can save energy consumption and related equipment investment;

[0020] (4) The reduction roasting kiln of the utility model has a built-in stirring paddle, which can stir the materials during the material movement process. The powdered materials have better looseness, and the materials are heated evenly and have better heat transfer efficiency, thereby improving the reduction roasting efficiency, effectively shortening the roasting time and saving energy consumption; at the same time, the stirring paddle is divided into a stirring shaft, a base, and blades. The stirring shaft and the base are made of nickel-based high-temperature resistant alloy. The blades are divided into sections and made of different alloy materials to adapt to the working environment under different temperature conditions. The blades can be disassembled and replaced, which effectively increases the service life of the bearings and the base and saves the cost of spare parts;

[0021] (5) The utility model uses the washed bag ash of the steel plant as the main raw material to recover the Zn, Fe and other elements therein, which can make better use of the carbon in the bag ash, reduce the amount of carbon powder added, and save the cost of auxiliary materials; the reasonable addition of washed sintering machine head ash during the reduction roasting process can improve the Pb grade in the zinc powder product, directly improve the product value, and the Fe in the machine head ash can also be recovered after reduction;

[0022] (6) The comprehensive recovery system of valuable elements in metallurgical dust and sludge of the utility model can effectively utilize and separate the valuable elements, has flexible processes, strong adaptability to raw materials, no secondary solid waste is generated, no wastewater is discharged, and is environmentally friendly. It can effectively grade and utilize the metallurgical dust removal ash of steel plants, and ultimately achieve the recovery and utilization of valuable elements, solving the problems of difficulty in direct reuse, low comprehensive utilization value, and secondary pollution generated during disposal. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Other features, objectives and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings.

[0024] Figure 1 This is a flow chart of water washing pretreatment of the comprehensive recovery method of valuable elements in metallurgical dust and sludge of the utility model;

[0025] Figure 2 It is a flow chart of valuable element recovery in the comprehensive recovery method of valuable elements in metallurgical dust and sludge of the utility model;

[0026] Figure 3 It is a structural schematic diagram of a comprehensive recovery system of valuable elements in metallurgical dust and mud according to the utility model;

[0027] Figure 4 It is a structural schematic diagram of the water washing pretreatment system of the utility model;

[0028] Figure 5 It is a structural schematic diagram of the potash recovery system of the utility model;

[0029] Figure 6 It is a schematic diagram of the reduction roasting kiln of the utility model. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is specifically described below in conjunction with the drawings in the specification. The detailed features and advantages of the present invention are described in detail in the specific implementation mode. The content is sufficient to enable any technical personnel in this field to understand the technical content of the present invention and implement it accordingly. According to the description, claims and drawings disclosed in this specification, technical personnel in this field can easily understand the relevant purposes and advantages of the present invention.

[0031] Figure 1 The pretreatment process flow chart of blast furnace bag ash and sintering machine head ash raw materials combined water washing is shown; Figure 2 The main process flow chart for comprehensive recovery of valuable elements in blast furnace bag ash and sintering machine head ash is shown. Figure 3 A schematic diagram of a reduction roasting kiln of the utility model is shown.

[0032] A comprehensive recovery method of valuable elements in metallurgical dust and sludge comprises the following steps:

[0033] S1. The pretreatment process of combined water washing of blast furnace bag ash and sintering machine head ash raw materials is as follows: Figure 1 shown.

[0034] S1 includes the following specific steps:

[0035] S11. The sintering machine head ash includes the one-two electric field sintering machine head ash and the three-four electric field sintering machine head ash. The blast furnace bag ash is rinsed with water, and then filtered to obtain the washed bag ash and bag ash rinsing liquid respectively; the blast furnace bag ash is the bag dust removal ash collected in the blast furnace ironmaking process of the steel plant, wherein Cl 5-10%, Zn≥5%, Fe 10-30%;

[0036] S12. The sintering machine head ash of the first and second electric fields and the sintering machine head ash of the third and fourth electric fields are respectively rinsed for the first time with bag ash rinsing liquid, and then filtered to obtain the first-washed first and second electric field machine head ash, the first-washed third and fourth electric field machine head ash and the machine head ash first rinsing liquid; the sintering machine head ash is the electrostatic dust removal ash collected in the sintering process of the steel plant, which is generally divided into four electric fields; among them, the sintering machine head ash of the first and second electric fields contains Cl 10-30%, K 10-30%, Na 1-10%, Pb 0-10%, and Fe10-30%; the sintering machine head ash of the third and fourth electric fields contains Cl 10-40%, K 10-30%, Na 1-10%, Pb 0-25%, Fe 10-30%, Au 5-20g / t, and Ag 300-1500g / t.

[0037] S13. The first water-washed one-two electric field machine head ash and the first water-washed three-four electric field machine head ash are rinsed with new water for the second time, and filtered after rinsing to obtain the washed one-two electric field machine head ash, washed three-four electric field machine head ash and machine head ash secondary rinsing liquid respectively. Among them, the solid ratio of the bag ash washing liquid is 1:1-4:1, the solid ratio of the first water washing liquid of the one-two electric field sintering machine head ash and the three-four electric field sintering machine head ash is 4:1-10:1; the solid ratio (dry basis) of the first water washing liquid of the one-two electric field sintering machine head ash and the three-four electric field sintering machine head ash is 1:1-4:1. The moisture content of washed bag ash, single-wash one-two electric field machine head ash, single-wash three-four electric field machine head ash, washed one-two electric field machine head ash, and washed three-four electric field machine head ash is 15-40%; the bag ash rinsing liquid is Cl 2.5-5%, K 0.1-2%, Na 0.1-2%; the machine head ash primary rinsing liquid is Cl 3-15%, K 3-15%, Na 1-10%; the machine head ash secondary rinsing liquid is Cl 0.5-5%, K 0.5-5%, Na 0.1-1%.

[0038] S2. The main process for comprehensive recovery of valuable elements in blast furnace bag ash and sintering machine head ash is as follows: Figure 2 shown.

[0039] S2 includes the following steps:

[0040] S21. Batching and mixing stage: the washed one-two electric field machine head ash in S13, the washed cloth bag ash in S11, carbon powder and other zinc-containing materials are mixed evenly in proportion to obtain a mixed material; wherein, the batching ratio of the washed one-two electric field machine head ash, the washed cloth bag ash, carbon powder and other zinc-containing materials (Cl≤5%) is adjusted according to the raw material composition. After batching, the main components in the mixture are shown in Table 1 below.

[0041] Table 1 Main components of the mixture

[0042] element Fe / % Pb / % Zn / % K / ％ Ca / % Cl / ％ Na / % C / ％ <![CDATA[H2O / %]]> content 20～50 1～3 8～15 ～2 4～8 ～2 ～1 5～20％ ～15

[0043] S22 reduction roasting stage: The mixed material in S21 enters the reduction roasting kiln, and the kiln slag is obtained by reduction roasting, and the flue gas generated is collected as zinc oxide dust by the dust collection system;

[0044] The mixed material enters the feed port of the reduction roasting kiln through the discharge belt and chute in turn, and obtains kiln slag after reduction roasting in the reduction roasting kiln, and the kiln slag is discharged from the discharge port of the reduction roasting kiln; the flue gas generated by the reduction roasting kiln is collected and dusted by the dust collection system to obtain zinc oxide dust.

[0045] Among them, the equipment schematic diagram of the reduction roasting kiln is as follows Figure 6 As shown. The reduction roasting kiln is provided with a preheating section A, a transition section B, a reduction section C, a cooling section D, and a discharging section E, wherein the temperature of the preheating section A is 200-500°C, the temperature of the transition section B is 500-900°C, the temperature of the reduction section C is 900-1300°C, the temperature of the cooling section D is 300-800°C, the temperature of the discharging section E is 800-300°C, the kiln length is 60m, the inner diameter of the kiln body is 5m, and the reduction roasting time is 60-180min. Gas and air burners are set in each section, and the reducing atmosphere in the reduction roasting kiln is adjusted by controlling the gas and air flow rates to ensure the reduction efficiency of the process; in order to ensure the heating uniformity and heat transfer effect of the material, a stirring paddle 43 of the material is provided in the reduction roasting kiln, and the stirring paddle 43 is composed of three parts: a stirring shaft, a base and a blade. The stirring shaft and the base are made of nickel-based high-temperature resistant alloy, and the blades are made of different alloy materials in different sections. The stirring paddle 43 is controlled to rotate in a direction (maximum rotation angle 30°) by a motor 44. During normal production, the stirring paddle 43 rotates in a direction opposite to the rotation direction of the reduction roasting kiln body, or the stirring paddle 43 is fixed. In addition, the reduction roasting kiln is also provided with a flue gas dust collection system 5 for collecting flue gas discharged from the reduction roasting kiln, and treating the flue gas to meet the emission standards.

[0046] S23. Magnetic separation of slag: flotation of slag in S22 to obtain carbon powder, which is returned to the S21 process; magnetic separation of flotation tailings to obtain magnetic iron powder and magnetic tailings, and the wastewater is circulated in the magnetic separation system;

[0047] S23 includes the following specific steps:

[0048] S231. Cooling the kiln slag in S22 to below 200°C, grinding and flotation to obtain carbon powder;

[0049] S232. The flotation tailings are subjected to two processes: strong magnetic roughing and strong magnetic sweeping, and finally magnetic iron powder and magnetic tailings are obtained; the magnetic iron powder is dehydrated and packaged for sale, and the magnetic tailings are settled and sold to cement plants. The magnetic iron powder TFe is 82.10% and MFe is 73.96%.

[0050] S233. Wastewater is circulated internally in the magnetic separation system.

[0051] S24. Reduction smelting selection stage: the washed three-fourth electric field machine head ash, quicklime and coal powder in S13 are mixed and then reduced and smelted to obtain crude lead and water-quenched slag, which are classified and processed.

[0052] S24 includes the following specific steps:

[0053] S241. The washed three or four electric field head ash, quicklime and coal powder in S13 are mixed and then reduced and smelted to obtain crude lead and water-quenched slag;

[0054] S242. The obtained crude lead is directly sold, and the obtained water-quenched slag is sent to the plate and frame filter press for filtration after the grinding process. The slag cake after filtration enters the S21 batching process.

[0055] Combination Figure 3-6 As shown, the utility model also provides a comprehensive recovery system of valuable elements in metallurgical dust and sludge for executing the above method, which comprises a water washing pretreatment system 1 and a valuable element recovery system.

[0056] Combination Figure 4 As shown, the water washing pretreatment system 1 is used for jointly washing blast furnace bag ash and sintering machine head ash; the water washing pretreatment system 1 comprises a bag ash water washing filter press module 11, a first sintering machine head ash water washing filter press module 12, and a second sintering machine head ash water washing filter press module 13; the bag ash water washing filter press module 11 is used for washing and filtering blast furnace bag ash to obtain washed bag ash, and the filtrate outlet of the bag ash water washing filter press module 11 is connected to the first sintering machine head ash water washing filter press module 12 and the second sintering machine head ash water washing filter press module 13 respectively. The water inlets of the washing filter press module 12 and the second sintering machine head ash washing filter press module 13 are connected; the first sintering machine head ash washing filter press module 12 uses the filtrate of the bag ash washing filter press module 11 to wash and filter the one-two electric field sintering machine head ash to obtain the washed one-two electric field machine head ash; the second sintering machine head ash washing filter press module 13 uses the filtrate of the bag ash washing filter press module 11 to wash and filter the three-four electric field sintering machine head ash to obtain the washed three-four electric field machine head ash;

[0057] Combination Figure 3 As shown, the valuable element recovery system includes a three-four electric field machine head ash reduction module 2, a batching module, a reduction roasting kiln 4, a dust collection system 5, and a grinding magnetic separation system 6; the three-four electric field machine head ash reduction module 2 is used to reduce and recover the lead in the water-washed three-four electric field machine head ash, and it includes a first mixer 21, a side-blowing furnace 22, a first water quenching tank 23, a first crushing device 24, a first grinding device 25 and a filter press 26 connected in sequence. The first mixer 21 mixes coal powder, quicklime, and water-washed three-four electric field machine head ash evenly, and then sends it to the side-blowing furnace 22 for reduction smelting to recover the lead in the water-washed three-four electric field machine head ash. Lead, the slag enters the first water quenching tank 23 for treatment to obtain water-quenched slag, the water-quenched slag is crushed by the first crushing equipment 24, ground by the first grinding equipment 25 and filtered by the filter press 26 to obtain slag cakes, which can enter the batching module to participate in the batching; the batching module is used to mix the water-washed one-two electric field machine head ash with the water-washed bag ash, carbon powder, and zinc-containing materials. The batching module includes a second mixer 3, which can mix the water-washed one-two electric field machine head ash with the water-washed bag ash, carbon powder, zinc-containing materials, etc. to obtain a mixed material; the discharge port of the batching module is connected to the reduction roasting kiln 4 through a discharge belt and a chute; combined Figure 6 As shown, the feed port 41 of the reduction roasting kiln 4 is connected to the discharge port of the batching module, and the discharge port 42 of the reduction roasting kiln 4 is connected to the grinding magnetic separation system 6; the reduction roasting kiln 4 is divided into a preheating section A, a transition section B, a reduction section C, a cooling section D, and a discharge section E in sequence, and a stirring paddle 43 for stirring the material is provided in the reduction roasting kiln 4, and the rotation direction of the stirring paddle 43 is controlled by a motor 44, and the cooling section D of the reduction roasting kiln 4 is provided with a flue gas outlet connected to the dust collection system; the dust collection system 5 is used to process the flue gas from the reduction roasting kiln 4 and recover zinc powder; the dust collection system 5 includes a waste heat boiler 51 connected to the discharge port of the reduction roasting kiln 4, and a flue gas treatment device 52 connected to the flue gas outlet of the waste heat boiler 51, and the gas treated by the flue gas treatment device 52 is discharged through the chimney; the grinding and magnetic separation system 6 is used to grind, float and magnetically separate the kiln slag of the reduction roasting kiln 4 to recover carbon powder and iron powder. The grinding and magnetic separation system 6 includes a water quenching tank 61, a second crushing equipment 62, a second grinding equipment 63, a flotation equipment 64, a strong magnetic rougher 65 and a strong magnetic sweeper 66 connected in sequence.

[0058] Combination Figure 4As shown, the bag ash water washing and filter pressing module 11 includes a first water washing device and a first filter press. The first sintering head ash water washing and filter pressing module 12 includes a second water washing device, a second filter press, a third water washing device and a third filter press connected in sequence; the water inlet of the second water washing device is connected to the filtrate outlet of the first filter press and the second first filter press; the filtrate outlet of the third water washing device and the third filter press is connected to the water inlet of the second water washing device. The second sintering head ash water washing and filter pressing module 13 includes a fourth water washing device, a fourth filter press, a fifth water washing device and a fifth filter press connected in sequence; the water inlet of the fourth water washing device is connected to the filtrate outlet of the first filter press and the second first filter press; the filtrate outlet of the fifth water washing device and the fifth filter press is connected to the water inlet of the fourth water washing device. The filtrate outlets of the second filter press and the fourth filter press are connected to the potassium salt recovery system 7.

[0059] Combination Figure 5 As shown, the potassium salt recovery system 7 includes a flotation device 71, an impurity removal device 72, and an evaporation crystallization system 73 which are connected in sequence; the flotation device 71 is connected to the filtrate outlets of the second filter press and the fourth filter press respectively.

[0060] Combination Figure 6 As shown, the stirring paddle 43 provided in the reduction roasting kiln 4 includes a stirring shaft passing through the inlet and outlet of the reduction roasting kiln, a base provided on the stirring shaft, and blades provided on the base; the stirring shaft and the base are made of nickel-based high-temperature resistant alloy, and the blades are divided into sections using different alloy materials.

[0061] The following is a detailed description of the preferred embodiments of the present invention:

[0062] Embodiment 1:

[0063] A comprehensive recovery system and method for valuable elements in metallurgical dust and sludge, comprising the following steps:

[0064] Raw materials are washed together: blast furnace bag ash is rinsed (liquid-solid ratio is 2:1), filtered after rinsing, and washed bag ash and bag ash rinsing liquid are obtained respectively; one-two electric field sintering machine head ash and three-four electric field sintering machine head ash are rinsed for the first time with bag ash rinsing liquid (liquid-solid ratio is 4:1), filtered after rinsing, and one-time washed one-two electric field machine head ash, one-time washed three-four electric field machine head ash and machine head ash first rinsing liquid are obtained; one-time washed one-two electric field machine head ash and one-time washed three-four electric field machine head ash are rinsed for the second time with new water (liquid-solid ratio is 2:1), filtered after rinsing, and one-time washed one-two electric field machine head ash, one-time washed three-four electric field machine head ash and machine head ash second rinsing liquid are obtained respectively; the blast furnace bag ash is mainly composed of Zn 8.23%, Fe30.81%, Cl 7.07%, Na 0.54%, Mg 0.85%, Ca The main components of the sintering head ash in the first and second electric fields are Zn 0.25%, Fe 34.92%, Pb 1.82%, Cl 8.20%, Na 2.33%, Mg0.73%, Ca 3.35%, K 6.56%; the main components of the sintering head ash in the third and fourth electric fields are Zn 0.49%, Fe 20.06%, Pb13.59%, Cl 17.36%, Na 3.53%, Mg 0.64%, Ca 3.27%, K 16.58%.

[0065] Batching and mixing: the above-mentioned water-washed one-two electric field machine head ash, water-washed cloth bag ash, carbon powder, and other zinc-containing materials (Cl≤5%) are mixed evenly in proportion to obtain a mixed material; the main components of the water-washed one-two electric field machine head ash are Zn0.29%, Fe41.08%, Pb2.14%, Cl1.01%, Na0.39%, Mg0.62%, Ca3.40%, K0.93%; wherein, the main components of the water-washed cloth bag ash are Zn9.14%, Fe34.23%, Cl1.33%, Na0.27%, Mg0.61%, Ca4.07%, K0.83%, C11.02%; wherein, the raw material ratio in the mixed material is shown in Table 2 below; the mixed material contains Fe40.59%, Pb1.40%, Zn8.90%, C15.77%, Na0.41%, K 0.80%, Cl 1.16%, Ca 3.25%.

[0066] Table 2: Raw material ratios in the mixed material in Example 1

[0067]

[0068]

[0069] Reduction roasting: The mixed materials are sequentially passed through the discharging belt and chute into the reduction roasting kiln, and the kiln slag is obtained after reduction roasting, wherein the preheating section temperature is 300°C, the transition section temperature is 800°C, the reduction section temperature is 1050°C, the cooling section temperature is 800°C, the discharging section temperature is 700°C, and the reduction roasting time is 90 minutes. The flue gas generated by the reduction roasting is collected by the dust collection system as zinc oxide dust, and the kiln slag is discharged from the discharging port of the reduction roasting kiln; the zinc oxide dust is mainly composed of Fe7.60%, Pb6.19%, and Zn60.46%.

[0070] Slag grinding, flotation and magnetic separation: the slag is cooled to below 200℃ and then enters the grinding and magnetic separation system, including grinding and flotation to obtain carbon powder and return the ingredients. The flotation tailings undergo two processes: strong magnetic roughing and strong magnetic sweeping, and finally magnetic iron powder and magnetic tailings are obtained. The magnetic iron powder is dehydrated and packaged for sale, and the magnetic tailings are settled and sold to cement plants. The wastewater is circulated in the magnetic separation system. The dehydrated magnetic iron powder has TFe82.10% and MFe73.96%.

[0071] Reduction smelting of water-washed three-four electric field machine head ash: The crude lead produced can also be sold directly; the water-quenched slag produced by this process is mechanically excited through the grinding process, filtered after grinding, and the filter cake is returned to the batching process. The main components of water-washed three-four electric field machine head ash are Zn 0.75%, Fe 30.86%, Pb 20.91%, Cl 1.14%, Na 0.42%, Mg 0.59%, Ca3.52%, K 1.38%; the main chemical composition of water-quenched slag is Zn 6.25%, Fe 23.94%, Mg 0.82%, Ca4.07%, Pb 0.03%, SiO2 15.28%.

[0072] Embodiment 2:

[0073] A comprehensive recovery system and method for valuable elements in metallurgical dust and sludge, comprising the following steps:

[0074] Raw materials are washed together: blast furnace bag ash is rinsed (liquid-solid ratio is 2:1), filtered after rinsing, and washed bag ash and bag ash rinsing liquid are obtained respectively; one-two electric field sintering machine head ash and three-four electric field sintering machine head ash are rinsed for the first time with bag ash rinsing liquid (liquid-solid ratio is 4:1), filtered after rinsing, and one-time washed one-two electric field machine head ash, one-time washed three-four electric field machine head ash and machine head ash first rinsing liquid are obtained; one-time washed one-two electric field machine head ash and one-time washed three-four electric field machine head ash are rinsed for the second time with new water (liquid-solid ratio is 3:1), filtered after rinsing, and washed one-two electric field machine head ash, washed three-four electric field machine head ash and machine head ash second rinsing liquid are obtained respectively; wherein, blast furnace bag ash is mainly composed of Zn 6.57%, Fe40.20%, Cl 4.80%, Mg 0.85%, Ca 3.66%, K The main components of the sintering head ash in the first and second electric fields are Zn 0.88%, Fe 22.82%, Pb 1.97%, Cl 28.05%, Na 4.65%, Mg 0.12%, Ca5.78%, and K 17.61%; the main components of the sintering head ash in the third and fourth electric fields are Zn 0.23%, Fe 8.70%, Pb 9.86%, Cl29.99%, Na 4.03%, Mg 0.06%, Ca 3.55%, and K 25.56%.

[0075] Batching and mixing: the above-mentioned washed one or two electric field machine head ash, washed cloth bag ash, carbon powder, and other zinc-containing materials (Cl≤5%) are mixed evenly in proportion to obtain a mixed material; the main components of the washed one or two electric field machine head ash are Zn1.6%, Fe41.49%, Pb3.58%, Cl2.38%, Na0.40%, Mg0.17%, Ca7.36%, K1.02%; wherein, the main components of the washed cloth bag ash are Zn6.84%, Fe41.87%, Cl0.57%, Mg0.71%, Ca2.67%, K0.21%, C8.29%; wherein, the specific raw material ratio in the mixed material is shown in Table 3; the mixed material contains Fe45.30%, Pb2.51%, Zn9.76%, C14.58%, Na0.25%, K0.42%, Cl 0.83%, Ca 4.22%.

[0076] Table 3: Raw material ratios in the mixed material in Example 2

[0077] Raw material name Washing one or two electric field machine head ash Washed bag ash Toner Other zinc-containing materials Return Water quenched slag Ratio / % 20 39 6 25 7 3

[0078] Reduction roasting: The mixed materials are sequentially passed through the discharging belt and chute into the reduction roasting kiln, and the kiln slag is obtained after reduction roasting, wherein the preheating section temperature is 250°C, the transition section temperature is 800°C, the reduction section temperature is 1000°C, the cooling section temperature is 800°C, the discharging section temperature is 700°C, and the reduction roasting time is 70 minutes. The flue gas generated by the reduction roasting is collected by the dust collection system as zinc oxide dust, and the kiln slag is discharged from the discharging port of the reduction roasting kiln; the zinc oxide dust is mainly composed of Fe6.65%, Pb 10.46%, and Zn58.90%.

[0079] Slag grinding, flotation and magnetic separation: The slag is cooled to below 200°C and then enters the grinding and magnetic separation system, including grinding and flotation to obtain carbon powder and return the ingredients. The flotation tailings undergo two processes: strong magnetic roughing and strong magnetic sweeping, and finally magnetic iron powder and magnetic tailings are obtained. The magnetic iron powder is dehydrated and packaged for sale, and the magnetic tailings are settled and sold to cement plants. The wastewater is circulated in the magnetic separation system. The dehydrated magnetic iron powder has a TFe of 85.33% and a MFe of 70.26%.

[0080] Reduction smelting of water-washed three-four electric field machine head ash: The crude lead produced can also be sold directly; the water-quenched slag produced by this process is mechanically excited through the grinding process, filtered after grinding, and the filter cake is returned to the batching process. The main components of water-washed three-four electric field machine head ash are Zn 0.51%, Fe 19.33%, Pb 21.91%, Cl 1.43%, Na 1.00%, Mg 0.11%, Ca5.52%, K 1.55%; the main chemical composition of water-quenched slag is Zn 5.08%, Fe 19.82%, Mg 0.54%, Ca4.97%, Pb 0.17%, SiO2 16.44%.

[0081] Finally, it should be pointed out that although the present invention has been described with reference to the current specific embodiments, ordinary technicians in this technical field should realize that the above embodiments are only used to illustrate the present invention and are not used as a limitation of the present invention. Various equivalent changes or substitutions can be made without departing from the concept of the present invention. Therefore, as long as the changes and modifications to the above embodiments are within the essential spirit of the present invention, they will fall within the scope of the claims of the present invention.

Claims

1. A comprehensive recovery system for valuable elements in metallurgical dust and sludge, characterized in that: Including water washing pretreatment system and valuable element recovery system; The water washing pretreatment system is used to jointly wash blast furnace bag ash and sintering machine head ash; The water washing pretreatment system comprises a bag ash water washing and filter pressing module, a first sintering machine head ash water washing and filter pressing module, and a second sintering machine head ash water washing and filter pressing module; the bag ash water washing and filter pressing module is used to wash and filter the blast furnace bag ash to obtain washed bag ash, and the filtrate outlet of the bag ash water washing and filter pressing module is respectively connected to the water inlet of the first sintering machine head ash water washing and filter pressing module and the second sintering machine head ash water washing and filter pressing module; the first sintering machine head ash water washing and filter pressing module uses the filtrate of the bag ash water washing and filter pressing module to wash and filter the one-two electric field sintering machine head ash to obtain washed one-two electric field machine head ash; The second sintering machine head ash water washing and filter pressing module uses the filtrate of the bag ash water washing and filter pressing module to wash and filter the three-four electric field sintering machine head ash to obtain the washed three-four electric field machine head ash; The valuable element recovery system includes a three-fourth electric field machine head ash reduction module, a batching module, a reduction roasting kiln, a dust collection system, and a grinding magnetic separation system; the three-fourth electric field machine head ash reduction module is used to reduce and recover the lead in the water-washed three-fourth electric field machine head ash, and it includes a first mixer, a side-blowing furnace, a first water quenching tank, a first crushing equipment, a first grinding equipment and a filter press connected in sequence; the batching module is used to evenly mix the water-washed one-two electric field machine head ash with the water-washed bag ash, carbon powder, and zinc-containing materials, and the discharge port of the batching module is connected to the reduction roasting kiln through a discharge belt and a chute; the reduction roasting kiln is divided into a preheating section, a transition section, a reduction section, a cooling section, and a discharge section in sequence, and the reduction A stirring paddle for stirring materials is arranged in the roasting kiln, and the rotation direction of the stirring paddle is controlled by a motor. A fume outlet connected to a dust collecting system is arranged in a cooling section of the reduction roasting kiln. The feed inlet of the reduction roasting kiln is connected to the discharge port of the batching module, and the discharge port of the reduction roasting kiln is connected to a grinding and magnetic separation system. The dust collecting system is used to process the fume coming out of the reduction roasting kiln and recover zinc powder. The grinding and magnetic separation system is used to grind, float and magnetically separate the kiln slag from the reduction roasting kiln, and recover carbon powder and iron powder. The grinding and magnetic separation system comprises a water quenching tank, a second crushing device, a second grinding device, a flotation device, a strong magnetic roughing machine and a strong magnetic sweeping machine which are connected in sequence.

2. A comprehensive recovery system for valuable elements in metallurgical dust and sludge as claimed in claim 1, characterized in that: The bag ash water washing and filter pressing module comprises a first water washing device and a first filter press; The first sintering machine head ash water washing and filter pressing module comprises a second water washing device, a second filter press, a third water washing device and a third filter press connected in sequence; the water inlet of the second water washing device is connected to the filtrate outlets of the first filter press and the second first filter press; the filtrate outlets of the third water washing device and the third filter press are connected to the water inlet of the second water washing device; The second sintering machine head ash water washing and filter pressing module comprises a fourth water washing device, a fourth filter press, a fifth water washing device, and a fifth filter press connected in sequence; the water inlet of the fourth water washing device is connected to the filtrate outlets of the first filter press and the second first filter press; the filtrate outlets of the fifth water washing device and the fifth filter press are connected to the water inlet of the fourth water washing device; The filtrate outlets of the second filter press and the fourth filter press are connected to a potassium salt recovery system.

3. A comprehensive recovery system for valuable elements in metallurgical dust and sludge as claimed in claim 2, characterized in that: The potassium salt recovery system comprises a flotation device, an impurity removal device, and an evaporation crystallization system which are connected in sequence; the flotation device is respectively connected to the filtrate outlets of the second filter press and the fourth filter press.

4. A comprehensive recovery system for valuable elements in metallurgical dust and sludge as claimed in claim 2, characterized in that: The stirring paddle provided in the reduction roasting kiln comprises a stirring shaft, a base provided on the stirring shaft and blades provided on the base; the stirring shaft and the base are made of nickel-based high temperature resistant alloy, and the blades are divided into sections and made of different alloy materials.

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