Zinc-containing steel scrap pellet based on putty powder and preparation method of zinc-containing steel scrap pellet

Abstract

The invention discloses a zinc-containing steel scrap pellet based on putty powder and a preparation method of the zinc-containing steel scrap pellet, and belongs to the field of metallurgical pellet production. The preparation method comprises the following steps: uniformly mixing the zinc-containing steel waste with a reducing agent to obtain a first mixture, and uniformly mixing the first mixture with putty powder to obtain a second mixture; and adding water into the second mixture, uniformly mixing to obtain a third mixture, standing the third mixture, pelletizing to obtain pellets, and drying the pellets to obtain the zinc-containing steel scrap pellets. The binder used in the invention is interior wall putty powder or waste putty powder regenerated material for building, has wide source, lower market price than other binders, environmental protection and wide application range, and the prepared pellet not only meets the furnace strength requirement, but also has low addition amount, and reduces the pelletizing cost. The method is suitable for industrial production, wide in application prospect and suitable for large-scale popularization and application.

Description

Technical Field

[0001] The present invention belongs to the technical field of metallurgical pellet production, and particularly relates to a zinc-containing iron and steel waste pellet based on putty powder and a preparation method thereof. Background Art

[0002] As a typical resource- and energy-intensive industry, the iron and steel industry consumes a large amount of resources and generates a large amount of solid waste during the production process. During the iron and steel production process, about 8% - 12% of the crude steel output will be converted into metallurgical dust and sludge. These metallurgical dust and sludge mainly come from the dust removal devices in the iron and steel production links such as sintering, smelting, and rolling, as well as the dust and sludge discharged during the wastewater treatment process, and usually contain elements such as iron and zinc.

[0003] In terms of the pyrometallurgical treatment of zinc-containing iron dust in steel plants, relatively mature processes in the world include the rotary kiln method and the rotary hearth furnace method, etc., which are all used in domestic production. The most important process in this process is the preparation process of carbon-containing pellets, and the quality of the pellets will directly affect the dezincification process effect and product quality.

[0004] In the prior art, Patent CN109022808A discloses a comprehensive recovery method for zinc-containing iron and steel metallurgical dust. After grinding various zinc-containing iron and steel metallurgical dusts, they are mixed with the reducing agent coke powder until the zinc content in the mixed material reaches more than 10%. Pulp or clay is used as a binder to make the mixed material into pellets or brick-like shapes, and then vacuum reduction smelting is carried out to obtain metallic zinc and metalized pellets mainly containing iron and carbon. In this patent, the binder used to improve the pellet strength is pulp or clay, and the dosage is as high as 4% - 6%, resulting in a relatively high pelletizing cost and low economic benefits. Patent CN106399700A discloses a method and system for treating zinc-containing iron and steel waste. The zinc-containing iron and steel waste, reducing agent, and binder are mixed, wet-ground, pelletized, and dried, and then high-temperature roasting is carried out through a rotary hearth furnace. The high-temperature flue gas enters the zinc recovery system to collect valuable metal dust, and the tailings are processed to obtain metallic iron powder. In this patent, a liquid binder is used, which is not conducive to the addition and mixing during the pelletizing process, and may ultimately lead to uneven strength of the finished pellets and inability to meet the furnace charging standard. It is generally found in the above patents that during the pelletizing process of zinc-containing iron and steel waste, there are problems such as high pelletizing cost due to large binder dosage, or uneven pellet strength due to the use of liquid binder, which affect the stable operation of the dezincification process. Therefore, how to improve the strength of zinc-containing iron and steel waste pellets and reduce the process cost has become the current research focus. Summary of the Invention

[0005] In order to solve the problems in the process of pelletizing zinc-containing iron and steel waste, such as the large amount of binder used resulting in too high pelletizing cost, or the uneven pellet strength caused by using liquid binder, the present invention provides a zinc-containing iron and steel waste pellet based on putty powder and its preparation method. The preparation method proposed by the present invention uses raw materials with low prices, and the prepared pellets have good performance, and can meet the strength requirements during the transportation of green pellets and the strength requirements of dry pellets when entering the furnace, thereby improving the economic benefits of products.

[0006] The present invention adopts the following technical solutions to solve the above technical problems: The present invention provides a preparation method of a zinc-containing iron and steel waste pellet based on putty powder. Mix zinc-containing iron and steel waste with a reducing agent evenly to obtain a first mixture, and mix the first mixture with putty powder evenly to obtain a second mixture; Add water to the second mixture and mix evenly to obtain a third mixture. Let the third mixture stand and then carry out pelletizing treatment to obtain pellets, and dry the pellets to obtain zinc-containing iron and steel waste pellets.

[0007] The zinc-containing iron and steel waste includes any one of converter dust, OG sludge or electric furnace dry dust removal ash; by mass percentage, the zinc-containing iron and steel waste includes 47% - 61% of Fe2O3, 9% - 18% of ZnO, 2% - 4% of SiO2, 1% - 3% of Al2O3, 1% - 6% of MgO, 4% - 8% of CaO, and the rest are impurities; the particle size of the zinc-containing iron and steel waste is 120 - 200 mesh.

[0008] The reducing agent is semi-coke or coke powder, the particle size of the reducing agent is 40 - 80 mesh, and the fixed carbon content in the reducing agent ≥ 75%; the addition amount of the reducing agent is 1.05 times - 1.2 times the total molar mass of iron and zinc in the zinc-containing iron and steel waste to be completely reduced.

[0009] The putty powder is an interior wall crack-resistant putty powder that meets the JG / T 298-2010 standard or recycled waste putty powder; by mass percentage, the putty powder includes 42% - 60% of CaCO3, 12% - 28% of 3MgO·4SiO2·H2O, 21% - 30% of CaSO4·2H2O, 1% - 5% of redispersible latex powder; the addition amount of the putty powder is 1.5% - 3% of the mass of the second mixture.

[0010] The recycled waste putty powder needs to be pretreated before use. The pretreatment includes: screening the waste putty powder to remove impurity particles with a particle size > 1mm; roasting the screened waste putty powder at 200 - 400°C for 1 - 2 hours, then grinding it after roasting, and screening it through a 200-mesh sieve to obtain the recycled waste putty powder.

[0011] Mix the zinc-containing steel waste with a reducing agent evenly to obtain a first mixture, and mix the first mixture with putty powder evenly to obtain a second mixture. Specifically: Stir the zinc-containing steel waste and the reducing agent for 6 - 8 minutes, then let it stand for 5 - 10 minutes to obtain the first mixture. Stir the first mixture and the putty powder for 6 - 8 minutes, then let it stand for 5 - 10 minutes to obtain the second mixture.

[0012] Add water to the second mixture and mix evenly to obtain a third mixture. Specifically: After adding water to the second mixture, stir for 6 - 8 minutes and then let it stand for 15 - 24 hours to obtain the third mixture; the dosage of water is 8wt% - 10wt% of the third mixture.

[0013] Let the third mixture stand and then perform pelletizing to obtain pellets. Specifically: Press the third mixture into pellets under a molding pressure of 12MPa - 16MPa.

[0014] Dry the pellets to obtain zinc-containing steel waste pellets. Specifically: Place the pellets in a vacuum environment at 40°C - 60°C and dry for 120 minutes - 180 minutes. The present invention also provides a zinc-containing steel waste pellet based on putty powder, which is obtained according to the preparation method of the zinc-containing steel waste pellet based on putty powder described above.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a new method for preparing pellets using putty powder as a pellet binder; the pellets obtained by this preparation process can not only meet the strength requirements, but also avoid the problem of impurities (such as SiO2) that may be introduced when using traditional binders such as cement and bentonite, thereby improving the quality of the pellets; putty powder has good physical and chemical properties as a binder and can provide sufficient bonding strength during the pellet production process to ensure that the pellets will not break or lose their shape during subsequent processing. The preparation process and binder provided by the present invention are not limited to the steel industry, and it can also be applied to the pelletizing process of other materials, such as iron ore powder, non-ferrous metal dust, etc.; the application of the putty powder binder of the present invention not only helps to reduce production costs and improve product quality, but also can effectively utilize waste resources, promote environmental protection and sustainable development, and has significant economic, environmental and social benefits, and is suitable for large-scale promotion and application.

[0016] Furthermore, the binder used in the present invention is mainly interior wall putty powder for construction or recycled waste putty powder. These materials are widely sourced and have relatively low market prices. The application of putty powder can greatly reduce production costs, thereby improving economic benefits; the utilization of waste putty powder as a binder not only helps to reduce resource waste, but also can effectively solve the problem of the disposal of construction waste, realizing the environmental protection concept of "treating waste with waste". Brief Description of the Drawings

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a flowchart of the preparation method of zinc-containing iron and steel waste pellets based on putty powder of the present invention. Detailed Embodiments

[0019] In order to make the technical problems to be solved, technical solutions and beneficial effects of the present application more clearly understood, the present application will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0020] In the present application, the term "and / or" describes the association relationship of associated objects and indicates that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. Where A and B may be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after.

[0021] In the present application, "at least one" means one or more, and "a plurality" means two or more. "At least one (item)" or its similar expression means any combination of these items, including any combination of single item (item) or plural items (items). For example, "at least one (item) of a, b, or c", or, "at least one (item) of a, b, and c" can both represent: a, b, c, a - b (i.e., a and b), a - c, b - c, or a - b - c, where a, b, and c can be single or multiple respectively.

[0022] It should be understood that in various embodiments of the present application, the magnitudes of the serial numbers of the above processes do not mean the order of execution. Some or all steps can be executed in parallel or sequentially. The execution order of each process should be determined by its function and internal logic and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0023] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms "a", "the", and "said" used in the embodiments of the present application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0024] In the description of the embodiments of the present application, the weights of the relevant components mentioned not only can refer to the specific contents of each component, but also can represent the proportional relationship of the weights between each component. Therefore, as long as the contents of the relevant components in the description of the embodiments of the present application are enlarged or reduced in proportion, they are within the scope disclosed in the description of the embodiments of the present application. Specifically, the mass described in the description of the embodiments of the present application can be mass units well-known in the chemical industry such as μg, mg, g, kg, etc.

[0025] As Figure 1 shown, it is a flow chart of the preparation method of the zinc-containing iron and steel waste pellet based on putty powder of the present invention. The zinc-containing iron and steel waste is mixed evenly with a reducing agent to obtain a first mixture, and the first mixture is mixed evenly with putty powder to obtain a second mixture; water is added to the second mixture and mixed evenly to obtain a third mixture, the third mixture is left standing and then pelletized to obtain pellets, and the pellets are dried to obtain zinc-containing iron and steel waste pellets.

[0026] In the following examples, unless otherwise specified, all materials used can be obtained through ordinary channels; the test methods adopted are conventional methods in the art.

[0027] Comparative Example 1 Pellets are prepared according to conventional binders and processes, including the following steps: Taking converter dust as raw material, by mass percentage, the components are 47.12% of Fe2O3, 9.33% of ZnO, 2.27% of SiO2, 1.15% of Al2O3, 1.06% of MgO, 4.52% of CaO, and the rest are impurities, with a particle size of 120 mesh. Semi-coke with a particle size of 40 mesh is added to the raw material to make C:O = 1.1, and then 4 wt% of calcium-based bentonite is added and continuously stirred for 20 min, and then 10 wt% of water is added and stirred for 10 min to obtain a mixed material; the mixed material is pressed into balls at 10 Mpa, and then the pellets are placed in a drying oven and dried at 120 °C for 4 h to obtain the finished product of Comparative Example 1.

[0028] Comparative Example 2 Pellets are prepared according to conventional binders and processes, including the following steps: Taking dried OG mud as raw material, the components are 55.43% of Fe2O3, 13.76% of ZnO, 3.18% of SiO2, 1.97% of Al2O3, 3.56% of MgO, 6.42% of CaO, and the rest are impurities, with a particle size of 160 mesh. Coke powder with a particle size of 60 mesh is added to the raw material to make C:O = 1.2, and then 4 wt% of sodium-based bentonite is added and continuously stirred for 20 min, and then 10 wt% of water is added and stirred for 10 min to obtain a mixed material; the mixed material is pressed into balls at 10 Mpa, and then the pellets are placed in a drying oven and dried at 120 °C for 4 h to obtain the finished product of Comparative Example 2.

[0029] Example 1 Prepare pellets according to the preparation method provided by the present invention, including the following steps: In this example, first, converter dust is selected as the main raw material of zinc-containing iron and steel waste. By mass percentage, the components of converter dust are 47.12% Fe2O3, 9.33% ZnO, 2.27% SiO2, 1.15% Al2O3, 1.06% MgO, 4.52% CaO, and the rest are impurities. The particle size of converter dust is 120 mesh; add semi-coke with a C:O ratio of 1.05 to the converter dust. The particle size of semi-coke is 40 mesh, the fixed carbon content is 75%, and the ash content is 2.1%. After stirring for 6 min and then standing for 5 min, the first mixture is obtained; add interior wall anti-cracking putty powder to the first mixture, stir for 6 min and then stand for 5 min to obtain the second mixture. The addition amount of interior wall anti-cracking putty powder accounts for 1.5 wt% of the second mixture. By mass percentage, the components of interior wall anti-cracking putty powder include 60% CaCO3, 23% CaSO4·2H2O, 5% redispersible latex powder (Vac / E), and 12% 3MgO·4SiO2·H2O; add water to the second mixture and continue to stir for 6 min to obtain the third mixture. The water addition amount accounts for 8 wt% of the third mixture; place the third mixture for 15 h, then press the third mixture into pellets at a molding pressure of 12 MPa to obtain pellets, and dry the pellets in a vacuum box at 40 °C for 120 min to obtain the finished product of Example 1.

[0030] Example 2 Prepare pellets according to the preparation method provided by the present invention, including the following steps: In this embodiment, first, the zinc-containing steel waste as the main raw material is selected as dried OG sludge. By mass percentage, the components of OG sludge are 55.43% of Fe2O3, 13.76% of ZnO, 3.18% of SiO2, 1.97% of Al2O3, 3.56% of MgO, 6.42% of CaO, and the rest are impurities. The particle size of OG sludge is 160 mesh; coke powder with a C:O ratio of 1.1 is added to the OG sludge. The particle size of the coke powder is 60 mesh, the fixed carbon content is 80%, and the ash content is 4.5%. After stirring for 7 minutes and standing for 8 minutes, the first mixture is obtained; interior wall anti-cracking putty powder is added to the first mixture, stirred for 7 minutes and then stood for 8 minutes to obtain the second mixture. The addition amount of the interior wall anti-cracking putty powder accounts for 2.2 wt% of the second mixture; by mass percentage, the components of the interior wall anti-cracking putty powder include 48% of CaCO3, 26% of CaSO4·2H2O, 22% of 3MgO·4SiO2·H2O, and 4% of redispersible latex powder (Vac / E); water is added to the second mixture and then stirred for 7 minutes to obtain the third mixture. The water addition amount accounts for 9 wt% of the third mixture; the third mixture is placed for 20 h, and then the third mixture is pressed into balls at a forming pressure of 14 MPa to obtain pellets. The pellets are dried in a vacuum box at 50 °C for 150 minutes to obtain the finished product of Example 2.

[0031] Example 3 Prepare pellets according to the preparation method provided by the present invention, including the following steps: In this embodiment, first, the zinc-containing steel waste as the main raw material is selected as the dry dedusting ash from an electric furnace. By mass percentage, the components of the dry dedusting ash from the electric furnace are 60.88% Fe2O3, 17.79% ZnO, 3.97% SiO2, 2.79% Al2O3, 5.81% MgO, 7.65% CaO, and the rest are impurities. The particle size of the dry dedusting ash from the electric furnace is 200 mesh. Semi-coke with a C:O ratio of 1.2 is added to the dry dedusting ash from the electric furnace. The particle size of the semi-coke is 80 mesh, the fixed carbon content is 85%, and the ash content is 5.7%. After stirring for 8 min, it is left standing for 10 min to obtain the first mixture; anti-cracking putty powder for interior walls is added to the first mixture and stirred for 8 min and then left standing for 10 min to obtain the second mixture. The addition amount of the anti-cracking putty powder for interior walls accounts for 3 wt% of the second mixture. By mass percentage, the components of the anti-cracking putty powder for interior walls include 55% CaCO3, 27% CaSO4·2H2O, 3% redispersible latex powder (Vac / E), and 15% 3MgO·4SiO2·H2O. Water is added to the second mixture and stirring is continued for 8 min to obtain the third mixture. The water addition amount accounts for 10 wt% of the third mixture; the third mixture is left standing for 24 h, and then the third mixture is pressed into balls at a forming pressure of 16 MPa to obtain pellets. The pellets are dried in a vacuum box at 60 °C for 180 min to obtain the finished product of Example 3.

[0032] Example 4 The pellets are prepared according to the preparation method provided by the present invention, including the following steps: In this embodiment, first, the zinc-containing steel scrap as the main raw material is selected as the electric furnace dry dedusting ash. By mass percentage, the components of the electric furnace dry dedusting ash are 57.17% of Fe2O3, 15.52% of ZnO, 3.67% of SiO2, 2.32% of Al2O3, 4.87% of MgO, 6.93% of CaO, and the rest are impurities. The particle size of the electric furnace dry dedusting ash is 200 mesh. Add semi-coke with a C:O ratio of 1.2 to the electric furnace dry dedusting ash. The particle size of the semi-coke is 80 mesh, the fixed carbon content is 85%, and the ash content is 5.7%. After stirring for 8 min and then standing for 10 min, the first mixture is obtained; collect the waste putty powder, screen out the impurity particles with a particle size > 1 mm, roast at 200 °C for 2 hours, and then pass through a 200-mesh sieve to obtain the waste putty powder recycled material; add the waste putty powder recycled material to the first mixture, stir for 8 min, and then stand for 10 min to obtain the second mixture. The addition amount of the waste putty powder recycled material accounts for 3 wt% of the second mixture; by mass percentage, the components of the waste putty powder recycled material include 50% of CaCO3, 20% of 3MgO·4SiO2·H2O, 28% of CaSO4·2H2O, and 2% of redispersible latex powder (Vac / E). Add water to the second mixture and continue to stir for 8 min to obtain the third mixture. The water addition amount accounts for 10 wt% of the third mixture; place the third mixture for 24 h, and then press the third mixture into balls at a forming pressure of 16 MPa to obtain pellets. Dry the pellets in a vacuum box at 60 °C for 180 min to obtain the finished product of Example 4.

[0033] Example 5 Prepare pellets according to the preparation method provided by the present invention, including the following steps: In this embodiment, first, converter dust, which is the main raw material containing zinc steel waste, is selected. By mass percentage, the components of converter dust are 51.64% Fe2O3, 12.84% ZnO, 3.63% SiO2, 1.72% Al2O3, 4.58% MgO, 5.88% CaO, and the rest are impurities. The particle size of the converter dust is 200 mesh; semi-coke with a C:O ratio of 1.2 is added to the converter dust. The particle size of the semi-coke is 80 mesh, the fixed carbon content is 85%, and the ash content is 5.7%. After stirring for 8 minutes and then standing for 10 minutes, the first mixture is obtained; the waste putty powder is collected, screened to remove impurity particles with a particle size > 1 mm, and calcined at 400 °C for 1 hour to obtain the waste putty powder regenerated material passing through a 200-mesh sieve. The waste putty powder regenerated material is added to the first mixture, stirred for 8 minutes, and then left standing for 10 minutes to obtain the second mixture. The addition amount of the waste putty powder regenerated material accounts for 3 wt% of the second mixture. By mass percentage, the components of the waste putty powder regenerated material include 42% CaCO3, 25% CaSO4·2H2O, 5% redispersible latex powder (Vac / E), and 28% 3MgO·4SiO2·H2O. Water is added to the second mixture and stirred for another 8 minutes to obtain the third mixture. The water addition amount accounts for 10 wt% of the third mixture; the third mixture is left standing for 24 hours, and then the third mixture is pressed into balls at a forming pressure of 16 MPa to obtain pellets. The pellets are dried in a vacuum box at 60 °C for 180 minutes to obtain the finished product of Example 5.

[0034] The green balls before drying and the finished products after drying in the above embodiments and comparative examples are tested for average compressive strength, average drop strength, etc. The test results are shown in Table 1: Table 1 Performance test table of products prepared in examples and comparative examples

[0035] As can be seen from Table 1, for the pellets manufactured by the conventional process represented by conventional binders (such as bentonite), the drop strength of the green balls is generally 4 - 6 times / 0.5 m, the drop strength of the dry balls is 0 - 1 time / 2 m, and the compressive strength is 30 - 80 N / piece. The strength of the pellets in the preferred implementation mode of the present invention is higher than that of the conventional process, and the effect of the pellets using the waste putty powder regenerated material (Examples 4 and 5) is the same as that of the interior wall putty powder (Examples 1, 2, and 3), indicating that using construction waste as a low-cost binder to achieve the purpose of "treating waste with waste" is feasible, and the pelletizing cost is lower than that of the conventional process, with wide applications.

[0036] In summary, the putty powder used in the present invention is an interior wall anti-cracking putty powder or recycled waste putty powder. These two substances, as binders, can significantly reduce the raw material cost in the pellet production process. Compared with traditional binders such as cement and bentonite, the market price of putty powder is lower, which can effectively reduce the production cost of enterprises and improve economic efficiency. Putty powder can also effectively provide bonding strength to ensure the quality stability of pellets; during the pellet production process, putty powder can be fully combined with other raw materials to form a solid pellet structure that will not easily break or lose its shape. The present invention prepares zinc-containing steel waste pellets with putty powder as the binder, providing an economical, environmentally friendly and sustainable innovative solution for industries such as steel.

[0037] In the ranges disclosed in the present invention, the endpoints and any values are not limited to the exact ranges or values. These ranges or values should be understood to include values close to these ranges or values. For numerical ranges, between the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values, they can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein. In the following text, in principle, the various technical solutions can be combined with each other to obtain new technical solutions, which should also be regarded as specifically disclosed herein.

[0038] The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art can still modify the specific implementation manners of the present invention or make equivalent replacements. Any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention are within the scope of the claims of the present invention pending approval.

Claims

1. A preparation method of zinc-containing iron and steel waste pellets based on putty powder, characterized in that, Mix the zinc-containing iron and steel waste uniformly with a reducing agent to obtain a first mixture, and mix the first mixture uniformly with putty powder to obtain a second mixture; Add water to the second mixture and mix uniformly to obtain a third mixture. Let the third mixture stand and then perform pelletizing to obtain pellets, and dry the pellets to obtain zinc-containing iron and steel waste pellets.

2. The preparation method of the zinc-containing iron and steel waste pellet based on putty powder according to claim 1, wherein, The zinc-containing iron and steel waste includes any one of converter fume, OG mud or dry electric furnace dedusting ash; By mass percentage, the zinc-containing iron and steel waste includes 47% - 61% of Fe2O3, 9% - 18% of ZnO, 2% - 4% of SiO2, 1% - 3% of Al2O3, 1% - 6% of MgO, 4% - 8% of CaO, and the rest are impurities; The particle size of the zinc-containing iron and steel waste is 120 - 200 mesh.

3. The preparation method of the zinc-containing iron and steel waste pellet based on putty powder according to claim 1, wherein, The reducing agent is semi-coke or coke powder. The particle size of the reducing agent is 40 - 80 mesh, and the fixed carbon content in the reducing agent is ≥75%; The dosage of the reducing agent is 1.05 - 1.2 times the total molar mass of iron and zinc in the zinc-containing iron and steel waste for complete reduction.

4. The preparation method of the zinc-containing steel waste pellet based on putty powder according to claim 1, wherein, The putty powder is an interior wall crack-resistant putty powder that meets the JG / T 298-2010 standard or recycled waste putty powder; By mass percentage, the putty powder includes 42% - 60% of CaCO3, 12% - 28% of 3MgO·4SiO2·H2O, 21% - 30% of CaSO4·2H2O, 1% - 5% of redispersible latex powder; The dosage of the putty powder is 1.5% - 3% of the mass of the second mixture.

5. The preparation method of the zinc-containing steel waste pellets based on putty powder according to claim 4, wherein The recycled waste putty powder needs to be pretreated before use. The pretreatment includes: Screen the waste putty powder to remove impurity particles with a particle size > 1 mm; roast the screened waste putty powder at 200 - 400 °C for 1 - 2 hours, then grind it after roasting, and screen it through a 200-mesh sieve to obtain recycled waste putty powder.

6. The preparation method of the zinc-containing steel waste pellets based on putty powder according to claim 1, characterized in that, The step of mixing the zinc-containing iron and steel waste uniformly with a reducing agent to obtain a first mixture, and mixing the first mixture uniformly with putty powder to obtain a second mixture is specifically: Stir the zinc-containing iron and steel waste and the reducing agent for 6 - 8 min, then let it stand for 5 - 10 min to obtain a first mixture. Stir the first mixture and the putty powder for 6 - 8 min, then let it stand for 5 - 10 min to obtain a second mixture.

7. The preparation method of the zinc-containing steel waste pellet based on putty powder according to claim 1, characterized in that, The step of adding water to the second mixture and mixing uniformly to obtain a third mixture is specifically: add water to the second mixture and stir for 6 - 8 min, then let it stand for 15 - 24 h to obtain a third mixture; The dosage of water is 8wt% - 10wt% of the third mixture.

8. The preparation method of the zinc-containing iron and steel waste pellet based on putty powder according to claim 1, characterized in that, The step of letting the third mixture stand and then performing pelletizing to obtain pellets is specifically: press the third mixture into pellets under a molding pressure of 12 MPa - 16 MPa.

9. The preparation method of the zinc-containing steel waste pellet based on putty powder according to claim 1, characterized in that, The step of drying the pellets to obtain zinc-containing iron and steel waste pellets is specifically: place the pellets in a vacuum environment at 40 °C - 60 °C and dry for 120 min - 180 min.

10. A zinc-containing steel scrap pellet based on putty powder, characterized in that, Prepare zinc-containing iron and steel waste pellets according to the preparation method of zinc-containing iron and steel waste pellets based on putty powder described in any one of claims 1 - 9.

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