Method for efficiently separating iron, lead and zinc from zinc smelting iron slag through hydrogen group direct reduction-electric smelting separation

Abstract

The invention belongs to the technical field of metallurgical dust solid waste treatment, and particularly relates to a method for efficiently separating iron, lead and zinc from zinc smelting iron slag through hydrogen group direct reduction-electric smelting separation. According to the method, lead, zinc and iron can be recycled in a stepped mode through hydrogen reduction-electric smelting separation. Through a hydrogen reduction process, lead and zinc oxides are reduced and volatilized to enter smoke dust to be enriched and recycled; and the reduced metallized pellets are smelted through the electric smelting separation furnace, slag-iron separation is achieved, molten iron is obtained, furnace charge is provided for steelmaking, efficient separation and enrichment of valuable metal in the zinc smelting iron slag are achieved, and the problem that iron cannot be recycled through a traditional technology is solved. The pregelatinized starch and the polyacrylamide in the composite additive are fully filled in microcracks, macromolecular bridging is formed among zinc smelting iron slag particles, the dispersed particles are connected, the bonding effect of the particles is improved, and the pellet strength is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of metallurgical dust solid waste treatment, and more particularly relates to a method for high-efficiency separation and recovery of iron, lead and zinc through hydrogen-based direct reduction-electric smelting of zinc smelting iron slag. BACKGROUND

[0002] Non-ferrous industry produces a variety of large amounts of difficult-to-treat waste slag in its smelting process, such as zinc smelting iron slag. The zinc smelting iron slag often has problems such as multiple valuable components, high content of harmful elements, large output, low product added value and difficult bulk disposal, and its utilization rate is less than 10%. Therefore, the resource utilization of the difficult-to-treat zinc smelting iron slag is directly related to the high-quality development of the non-ferrous industry.

[0003] However, the zinc smelting iron slag contains multiple heavy metals and is a typical hazardous waste, which must be properly disposed of. The resource utilization of the difficult-to-treat iron slag is directly related to the survival and sustainable development of the non-ferrous industry. On the other hand, the non-ferrous metal iron slag has a high content of valuable metals (especially strategic metal elements-iron) and great value, and is a valuable secondary resource. Therefore, the efficient utilization of the difficult-to-treat non-ferrous multi-metal iron slag helps the high-quality development of the non-ferrous industry.

[0004] The key to the comprehensive utilization of zinc smelting iron slag is how to economically and efficiently recover and separate multiple valuable metal components. At present, domestic and foreign researches mainly focus on recovering part of non-ferrous metal elements through wet leaching, pyrometallurgical beneficiation or combined smelting and metallurgy technologies. At present, solidification and stacking and high-temperature pyrometallurgical disposal are widely used. Undoubtedly, the solidification and stacking technology cannot effectively recover a large amount of valuable metals, resulting in serious waste of resources. The high-temperature pyrometallurgical process mainly includes molten bath smelting (smelting in a fume furnace, electric furnace method and Ausmelt furnace) and solid direct reduction method (rotary kiln direct reduction). The molten smelting has high temperature, high energy consumption, serious refractory material loss and high cost, and a large amount of iron cannot be recovered. The rotary kiln technology for treating zinc smelting iron slag is mature and is widely used at home and abroad. However, the traditional rotary kiln process uses powder into the kiln, which is easy to cause rotary kiln ring, low grade of secondary zinc oxide and difficult zinc recovery. The reduction product has low metallization rate, and iron cannot be efficiently utilized, which not only causes waste of energy and resources, but also makes the secondary slag difficult to dispose. In addition, the current pyrometallurgical disposal mainly uses coal as a reducing agent, which has high energy consumption and large carbon emissions.

[0005] Therefore, how to develop a clean and efficient hydrogen-based direct reduction-electric smelting method for high-efficiency separation and recovery of iron, lead and zinc from zinc smelting iron slag is a technical problem that needs to be solved by those skilled in the art. SUMMARY

[0006] In order to overcome the shortcomings and deficiencies in the prior art, the application provides a method for high-efficiency separation and recovery of iron, lead and zinc through hydrogen-based direct reduction-electric smelting of zinc smelting iron slag.

[0007] To achieve the above object, the present application adopts the following technical solutions:

[0008] A method for efficiently separating iron, lead and zinc by zinc smelting iron slag hydrogen-based direct reduction-electric smelting, comprising the following steps:

[0009] S1, batching: uniformly mixing zinc smelting iron slag and composite additives to obtain a mixture;

[0010] S2, pretreatment: wetting the mixture with water and performing high-pressure roller grinding pretreatment;

[0011] S3, balling: uniformly mixing the pretreated mixture obtained in step S2, balling, and screening to obtain green balls;

[0012] S4, oxidation roasting: drying, preheating, roasting and soaking of the green balls obtained in step S3 to prepare high-strength oxidized pellets;

[0013] S5, hydrogen-based reduction: loading the oxidized pellets obtained in step S4 into a hydrogen-based shaft furnace for reduction to obtain lead and zinc-containing reduced dust and reduced dezincification metallized pellets;

[0014] S6, electric furnace separation: electric furnace separation of the metallized pellets obtained in step S5 to obtain molten iron and separation slag.

[0015] Preferably, the zinc smelting iron slag includes at least one of fuming furnace slag, zinc sink iron slag, side-blown furnace slag, and rotary kiln roasting slag.

[0016] Preferably, the composite additive includes, by mass fraction, 5-15% pregelatinized starch, 5-10% polyacrylamide, and 75-90% high-magnesium powder.

[0017] Preferably, the mass ratio of the composite additive to the zinc smelting iron slag is 5-15:85-95.

[0018] Preferably, the specific operation of step S2 includes: adding water to the mixture obtained in step S1 for wetting, the mass ratio of the mixture to water is 90-92:8-10, the wetting time is 5-10 min, and the stacking and covering curing time is 10-30 min; the high-pressure roller grinding pressure is 1.0-2.0 N / mm 2 , and the edge material circulation ratio is 30-50%.

[0019] Preferably, the specific operation of step S3 includes: uniformly mixing the pretreated mixture obtained in step S2, adding it to a disc balling machine for balling, the balling time is 10-15 min, the green ball moisture is 11-13%, and the green ball average particle size is 12-16 mm.

[0020] Preferably, the specific operation of the step S4 comprises: preparing oxidized pellets by using a belt-type roaster, the drying temperature of the green pellets is 200-350 DEG C, the drying air speed is 0.8-1.2 m / s, the drying time is 3-5 min, and the material layer height is 300-500 mm; the preheating temperature is 700-900 DEG C, the preheating air speed is 2.2-2.6 m / s, and the preheating time is 15-20 min; the roasting temperature is 1000-1100 DEG C, the roasting air speed is 2.2-2.6 m / s, and the roasting time is 10-15 min; the soaking temperature is 800-900 DEG C, the soaking air speed is 2.0-2.2 m / s, and the soaking time is 3-5 min.

[0021] Preferably, the specific operation of the step S5 comprises: loading the oxidized pellets obtained in the step S4 into a hydrogen-based shaft furnace for reduction, the reduction temperature is 850-1050 DEG C, and the reduction time is 90-180 min; the reduction gas comprises 50-100% H2, 0-40% CO, and 0-10% CO2 in terms of volume fraction.

[0022] Preferably, the specific operation of the step S6 comprises: high-temperature smelting and separating the metallized pellets obtained in the step S5, the smelting and separating temperature is 1500-1600 DEG C, the smelting and separating time is 30-60 min, and the basicity is 0.8-1.2.

[0023] Via the technical solution described above, compared with the prior art, the present application provides a method for efficiently separating iron, lead and zinc through zinc smelting iron slag hydrogen-based direct reduction and electric smelting and separation, and has the following beneficial effects:

[0024] (1) In view of the problem that the traditional zinc smelting iron slag recovery method only recovers lead and zinc, and the iron with higher content and greater value cannot be recovered, the present application can recover lead, zinc and iron in stages through hydrogen reduction and electric smelting and separation. Through the hydrogen reduction process, the lead and zinc oxides are reduced and volatilized into the flue dust to be enriched and recovered; the reduced metallized pellets are smelted by an electric smelting and separation furnace to realize slag-iron separation and obtain molten iron, which provides furnace charge for steelmaking, and realizes efficient separation and enrichment of valuable metals in zinc smelting iron slag, thereby breaking through the problem that iron cannot be recovered in the traditional process.

[0025] (2) In view of the problem that the traditional zinc smelting iron slag uses coal as a reducing agent and energy, resulting in high energy consumption and large carbon emissions, the present application provides an "electric-hydrogen" coupling mode, uses hydrogen metallurgy to replace the traditional carbon metallurgy, thereby reducing carbon emissions; uses green electricity as a carrier to realize green electricity-green hydrogen smelting, thereby breaking through the bottleneck of large carbon emissions and high energy consumption in the traditional technology.

[0026] (3) In view of the low surface activity and poor ballability of the zinc smelting iron slag, which leads to low green ball strength, and the high content of SiO2 in the gangue component in the slag, which is prone to react with FeO to produce low-melting-point fayalite liquid phase in the reduction process, filling the internal pores of the pellets, and blocking the zinc and lead volatilization channels, resulting in low lead and zinc volatilization rates, a composite additive (pre-gelatinized starch, polyacrylamide and high-magnesium powder) and high-pressure roller grinding pretreatment technology are developed. Through the high-pressure roller grinding pretreatment process, isostatic pressure is generated, a large number of microcracks are generated in the zinc smelting iron slag particles, and the pre-gelatinized starch and polyacrylamide in the composite additive are fully filled in the microcracks to form a high-molecular bridging (bridging effect) between the zinc smelting iron slag particles, connecting the dispersed particles and increasing the bonding effect, thereby improving the pellet strength. At the same time, the MgO in the high-magnesium powder in the composite binder reacts with SiO2 to form high-melting-point olivine minerals, which inhibits the formation of liquid phase in the reduction process, avoids the blockage of pores, improves the iron reduction and lead and zinc reduction volatilization kinetics, and thus improves the pellet metallization rate and the lead and zinc reduction volatilization rate. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only a part of the embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the provided drawings.

[0028] Figure 1 The process flow chart of the method of the present application.

[0029] Figure 2 The microstructure of the metallized pellets obtained in step S5 of Example 3. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0031] Comparative Example 1

[0032] Zinc-containing dust pellets were prepared according to the conventional balling process, including the following steps:

[0033] S1, batching: smoke furnace slag, i.e. iron slag produced in the smoke furnace during zinc smelting;

[0034] S2, pretreatment: the fuming furnace slag is wetted by adding water, the mass ratio of fuming furnace slag to water is 92:8, the wetting time is 6 min, and the fuming furnace slag is stored and covered for 12 min to mature; and high-pressure roller grinding pretreatment is performed, the grinding high-pressure roller grinding pressure is 1.0 N / mm 2 , the edge material circulation ratio is 30%;

[0035] S3, balling: the pretreated mixture obtained in step S2 is uniformly mixed, and is added into a disc balling machine for balling and screening; the balling time is controlled to be 12 min, and the moisture of the green ball is 12%; the prepared green ball has a drop strength of only 1.2 times / (0.5 m), a compression strength of 8.9 N / each, and a burst temperature of 280℃;

[0036] S4, oxidizing roasting: the green ball obtained in step S3 is loaded into a belt roaster for drying, preheating and roasting to prepare high-strength oxidized pellets; the drying temperature of the green ball is 200℃, the drying air speed is 0.8 m / s, the drying time is 5 min, and the layer height is 300 mm; the preheating temperature is 900℃, the preheating air speed is 2.2 m / s, and the preheating time is 20 min; the roasting temperature is 1100℃, the roasting air speed is 2.2 m / s, and the roasting time is 10 min; the soaking temperature is 900℃, the soaking air speed is 2.2 m / s, and the soaking time is 5 min; the prepared oxidized pellets have a strength of only 1578 N / each;

[0037] S5, hydrogen-based reduction: the oxidized pellets obtained in step S4 are loaded into a hydrogen-based shaft furnace for reduction. The reduction temperature is 1050℃, the reduction time is 180 min, and the reduction gas includes 80% H2 and 20% CO in terms of volume fraction. The reduction pellet metallization rate is 72.3%, and the reduction and volatilization rates of zinc and lead are 82.6% and 84.5%, respectively. In addition, secondary zinc oxide containing 50.1% zinc is recovered from the flue dust. Due to the serious pellet pulverization and large amount of dust, the mineral powder is mixed into the flue dust, resulting in low grade of the secondary zinc oxide. The requirement for entering the furnace cannot be met;

[0038] S6, electric furnace melting and separation: the dezincification and metallization pellets obtained in step S5 are melted and separated in an electric furnace, the melting and separation temperature is 1600℃, the melting and separation time is 60 min, and the basicity is 1.2, and the obtained molten iron has an iron grade of 95.4% and an iron recovery rate of 80.2%.

[0039] Example 1

[0040] S1, batching: the fuming furnace slag and the composite additive are batched in a mass ratio of 95:5, wherein the composite additive includes, in terms of mass fraction, 10% pre-gelatinized starch, 10% polyacrylamide, and 80% high-magnesium powder;

[0041] S2, pretreatment: water is added to the mixture obtained in step S1 for wetting, the mass ratio of the mixture to water is 90:10, the wetting time is 6 min, and the mixture is stored and aged for 12 min; and high-pressure roller grinding pretreatment is performed, the grinding high-pressure roller grinding pressure is 1.0 N / mm 2 , and the edge material circulation ratio is 30%;

[0042] S3, balling: the pretreated mixture obtained in step S2 is uniformly mixed, and is added to a disc balling machine for balling and screening; the balling time is controlled to be 12 min, the moisture of the green ball is 13%, and the average particle size of the green ball is 12 mm; the prepared green ball has a falling strength of 4.6 times / (0.5 m), a compressive strength of 15.4 N / each, and a burst temperature of 320℃;

[0043] S4, oxidizing roasting: the green ball obtained in step S3 is loaded into a belt roaster for drying, preheating, roasting, and soaking to prepare high-strength oxidized pellets; the drying temperature of the green ball is 300℃, the drying air speed is 1.2 m / s, the drying time is 5 min, and the layer height is 300 mm; the preheating temperature is 900℃, the preheating air speed is 2.2 m / s, and the preheating time is 20 min; the roasting temperature is 1100℃, the roasting air speed is 2.2 m / s, and the roasting time is 12 min; the soaking temperature is 900℃, the soaking air speed is 2.2 m / s, and the soaking time is 5 min; the prepared oxidized pellets have a strength of 2324 N / each;

[0044] S5, hydrogen-based reduction: the oxidized pellets obtained in step S4 are loaded into a hydrogen-based shaft furnace for reduction, the reduction temperature is 1050℃, and the reduction time is 180 min; the reduction gas includes 80% H2 and 20% CO in terms of volume fraction; the reduction pellet metallization rate is 78.89%, and the reduction and volatilization rates of zinc and lead are 88.67% and 90.24%, respectively. In addition, secondary zinc oxide containing 65.4% zinc is recovered from the flue dust;

[0045] S6, electric furnace melting and separation: the dezincification and metallization pellets obtained in step S5 are melted and separated in an electric furnace, the melting and separation temperature is 1600℃, the melting and separation time is 60 min, and the basicity is 1.2; the obtained molten iron has an iron grade of 95.8% and an iron recovery rate of 84.66%.

[0046] Example 2

[0047] S1, batching: the flue dust and the composite additive are batched in a mass ratio of 90:10, wherein the composite additive includes, in terms of mass fraction, 12% pregelatinized starch, 8% polyacrylamide, and 80% high-magnesium powder;

[0048] S2, pretreatment: water is added to the mixture obtained in step S1 for wetting, the mass ratio of the mixture to water is 90:10, the wetting time is 8 min, and the mixture is stored and aged for 14 min; and high-pressure roller grinding pretreatment is performed, the grinding high-pressure roller grinding pressure is 1.5 N / mm 2 , the edge material circulation ratio is 40%;

[0049] S3, balling: the pretreated mixture obtained in step S2 is uniformly mixed, and is added into a disc balling machine for balling and screening; the balling time is controlled to be 12 min, the moisture of the green ball is 13%, and the average particle size of the green ball is 12.5 mm; the prepared green ball has a falling strength of 6.8 times / (0.5 m), a compressive strength of 19.6 N / each, and a burst temperature of 330℃;

[0050] S4, oxidizing roasting: the green ball obtained in step S3 is loaded into a belt roaster for drying, preheating, roasting and soaking to prepare high-strength oxidized pellets; the drying temperature of the green ball is 320℃, the drying air speed is 1.2 m / s, the drying time is 5 min, and the layer height is 350 mm; the preheating temperature is 900℃, the preheating air speed is 2.2 m / s, and the preheating time is 15 min; the roasting temperature is 1100℃, the roasting air speed is 2.2 m / s, and the roasting time is 12 min; the soaking temperature is 900℃, the soaking air speed is 2.2 m / s, and the soaking time is 3 min; the prepared oxidized pellets have a strength of 2578 N / each;

[0051] S5, hydrogen-based reduction: the oxidized pellets obtained in step S4 are loaded into a hydrogen-based shaft furnace for reduction, the reduction temperature is 1050℃, and the reduction time is 90 min; the reduction gas includes 80% H2 and 20% CO in terms of volume fraction; the reduction pellet metallization rate is 83.45%, and the reduction and volatilization rates of zinc and lead are 92.13% and 93.56%, respectively; in addition, secondary zinc oxide containing 70.21% of zinc is recovered from the flue dust;

[0052] S6, electric furnace melting and separation: the dezincification and metallization pellets obtained in step S5 are melted and separated in an electric furnace, the melting and separation temperature is 1600℃, the melting and separation time is 60 min, and the basicity is 1.2; the obtained molten iron has an iron grade of 95.6% and an iron recovery rate of 87.88%.

[0053] Example 3

[0054] S1, batching: the flue dust and the composite additive are batched in a mass ratio of 85:15, wherein the composite additive includes, in terms of mass fraction, 15% pre-gelatinized starch, 9% polyacrylamide, and 76% high-magnesium powder;

[0055] S2, pretreatment: water is added to the mixture obtained in step S1 to perform wetting, the mass ratio of the mixture to water is 90:10, the wetting time is 8 min, the material is stored and covered for aging for 14 min; and high-pressure roller grinding pretreatment is performed, the grinding high-pressure roller grinding pressure is 2.0 N / mm 2 , the edge material circulation ratio is 40%;

[0056] S3, balling: the pretreated mixture obtained in step S2 is uniformly mixed, and is added into a disc balling machine to perform balling and screening; the balling time is controlled to be 12 min, the green ball moisture is 13%, and the average particle size of the green ball is 13 mm; the prepared green ball has a falling strength of 10.2 times / (0.5 m), a compressive strength of 24.56 N / each, and a burst temperature of 350℃;

[0057] S4, oxidizing roasting: the green ball obtained in step S3 is loaded into a belt roaster to perform drying, preheating, roasting and soaking to prepare high-strength oxidized pellets; the drying temperature of the green ball is 350℃, the drying air speed is 1.1 m / s, the drying time is 4 min, and the material layer height is 500 mm; the preheating temperature is 900℃, the preheating air speed is 2.2 m / s, and the preheating time is 18 min; the roasting temperature is 1100℃, the roasting air speed is 2.2 m / s, and the roasting time is 15 min; the soaking temperature is 900℃, the soaking air speed is 2.2 m / s, and the soaking time is 3 min; the prepared oxidized pellets have a strength of 2967 N / each;

[0058] S5, hydrogen-based reduction: the oxidized pellets obtained in step S4 are loaded into a hydrogen-based shaft furnace to perform reduction, the reduction temperature is 1050℃, and the reduction time is 90 min; the reduction gas includes 80% H2, 10% CO and 10% CO2 in terms of volume fraction; the reduction pellet metallization rate is 88.92%, and the reduction and volatilization rates of zinc and lead are 96.44% and 97.88% respectively; in addition, secondary zinc oxide containing 74.5% of zinc is recovered from the flue dust;

[0059] S6, electric furnace melting and separation: the dezincified metallized pellets obtained in step S5 are subjected to electric furnace melting and separation, the melting and separation temperature is 1550℃, the melting and separation time is 60 min, and the basicity is 1.0; under the above conditions, the hot metal iron grade is 95.7%, and the iron recovery rate is 90.24%.

[0060] Figure 2 The microstructure of the metallized pellets obtained in step S5 of Example 3 is shown in FIG. 2. Figure 2 As shown in FIG. 2, after reduction, most of the oxygen is removed, and iron exists in the form of metallic iron; in addition, the content of lead and zinc in the metallized pellets is extremely low, which indicates that the reduction and volatilization effect is good. By using the technology, efficient reduction of iron and reduction and removal of lead and zinc in the smelting slag are realized.

[0061] The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Modifications of these embodiments will occur to persons of skill in the art, and that the appended claims are intended to cover all such modifications that do not depart from the true spirit and scope of the application. Therefore, the application is not limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for efficient separation of iron, lead, and zinc from zinc smelting slag using hydrogen-based direct reduction and electrofusion, characterized in that... Includes the following steps: S1. Ingredients: Mix zinc smelting slag and composite additives to obtain a mixture; S2. Pretreatment: Wet the mixture with water and pretreat it by high-pressure roller milling; S3. Pelletizing: Mix the pretreated mixture obtained in step S2, pelletize, and sieve to obtain green pellets; S4. Oxidative calcination: The green pellets obtained in step S3 are dried, preheated, calcined and homogenized to prepare high-strength oxidized pellets; S5, Hydrogen-based reduction: The oxide pellets obtained in step S4 are loaded into a hydrogen-based vertical shaft furnace for reduction to obtain lead- and zinc-containing reduction flue dust and reduced dezincified metallized pellets. S6. Electric furnace melting: The metallized pellets obtained in step S5 are melted in an electric furnace to obtain molten iron and slag.

2. The method for efficient separation of iron, lead, and zinc from zinc smelting slag using hydrogen-based direct reduction-electrospray separation according to claim 1, characterized in that, The zinc smelting slag includes at least one of the following: fuming furnace slag, zinc-iron slag, side-blown furnace slag, and rotary kiln roasting slag.

3. The method for efficient separation of iron, lead, and zinc from zinc smelting slag using hydrogen-based direct reduction-electrospray separation according to claim 1, characterized in that, The composite additive, by mass fraction, includes 5-15% pregelatinized starch, 5-10% polyacrylamide, and 75-90% high magnesium powder.

4. The method for efficient separation of iron, lead, and zinc from zinc smelting slag using hydrogen-based direct reduction-electrospray separation according to claim 1, characterized in that, The mass ratio of the composite additive to zinc smelting slag is 5-15:85-95.

5. The method for efficient separation of iron, lead, and zinc from zinc smelting slag using hydrogen-based direct reduction-electrospray separation according to claim 1, characterized in that, The specific operations of step S2 include: adding water to the mixture obtained in step S1 for wetting, with a mass ratio of mixture to water of 90-92:8-10, a wetting time of 5-10 minutes, and piling and curing the material for 10-30 minutes; the pressure of the high-pressure roller mill is 1.0-2.0 N / mm. 2 The scrap recycling rate is 30% to 50%.

6. The method for efficient separation of iron, lead, and zinc from zinc smelting slag using hydrogen-based direct reduction-electrospray separation according to claim 1, characterized in that, The specific operation of step S3 includes: mixing the pretreated mixture obtained in step S2, adding it to a disc pelletizer for pelletizing, with a pelletizing time of 10 min to 15 min, a raw pellet moisture content of 11% to 13%, and an average raw pellet size of 12 mm to 16 mm.

7. The method for efficient separation of iron, lead, and zinc from zinc smelting slag using hydrogen-based direct reduction-electrosmelting fractionation according to claim 1, characterized in that, The specific operations of step S4 include: preparing oxidized pellets using a belt calciner; drying the green pellets at a temperature of 200℃~350℃, a drying air velocity of 0.8~1.2m / s, a drying time of 3min~5min, and a material layer height of 300mm-500mm; preheating at a temperature of 700℃~900℃, a preheating air velocity of 2.2~2.6m / s, and a preheating time of 15min~20min; calcining at a temperature of 1000℃~1100℃, a calcining air velocity of 2.2~2.6m / s, and a calcining time of 10min~15min; and homogenizing at a temperature of 800℃~900℃, a homogenizing air velocity of 2.0~2.2m / s, and a homogenizing time of 3min~5min.

8. The method for efficient separation of iron, lead, and zinc from zinc smelting slag using hydrogen-based direct reduction-electrospray separation according to claim 1, characterized in that, The specific operation of step S5 includes: hot charging the oxidized pellets obtained in step S4 into a hydrogen-based vertical furnace for reduction, with a reduction temperature of 850-1050℃ and a reduction time of 90-180min; the reducing gas, by volume fraction, includes 50%-100% H2, 0-40% CO, and 0-10% CO2.

9. The method for efficient separation of iron, lead, and zinc from zinc smelting slag using hydrogen-based direct reduction-electrospray separation according to claim 1, characterized in that, The specific operation of step S6 includes: performing high-temperature melting and separation on the metallized pellets obtained in step S5, with a melting and separation temperature of 1500-1600℃, a melting and separation time of 30-60 min, and an alkalinity of 0.8-1.2.

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