Resource utilization process for high-zinc metallurgical dust and sludge

Abstract

The invention discloses a resource utilization process for high-zinc metallurgical dust and sludge. The resource utilization process comprises the following steps: S1, uniformly mixing the high-zinc metallurgical dust and sludge, a binder, a reducing agent and water to obtain a mixture; s2, the mixture is formed and dried and then fed into a rotary hearth furnace to be subjected to reduction roasting, and zinc-containing flue gas, metallized pellets and metallized pellet powder are generated; and S3, the metallized pellet powder serves as a raw material to be added into an artificial stone manufacturing process, and the artificial stone is obtained. The rotary hearth furnace process is matched with the artificial stone manufacturing process, valuable metal in the high-zinc metallurgical dust and sludge is converted into metal products through the rotary hearth furnace process, the low-quality metallized pellet powder produced by the rotary hearth furnace serves as a raw material to be matched with the artificial stone manufacturing process, and the high-quality artificial stone is manufactured. The comprehensive utilization of the high-zinc metallurgical dust and sludge is realized.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgical dust and sludge utilization, and in particular relates to a process for resource utilization of high-zinc metallurgical dust and sludge. Background Art

[0002] A large amount of iron-containing and zinc-containing metallurgical dust and mud will be generated during the steel production process. Since the metallurgical dust and mud contain harmful impurities such as zinc, chlorine, potassium, and sodium, especially high-zinc metallurgical dust and mud with a zinc content of >0.5%, if it is directly returned to ironmaking or steelmaking production, it will have a great negative impact on the smelting production process. Therefore, high-zinc metallurgical dust and mud must be dezincified before it can be returned to the main smelting production process such as ironmaking or steelmaking. Currently, a variety of processes for metallurgical dust and mud treatment have been developed, such as rotary hearth furnaces and rotary kilns. After being treated by processes such as rotary hearth furnaces and rotary kilns, the zinc in high-zinc dust and mud can be removed and recovered in the dust. However, the products produced by these processes after roasting are mainly metallized pellets and metallized pellet powder. Since the quality of metallized pellets is high, they can be directly returned to the main smelting production process such as ironmaking or steelmaking as raw materials, but the zinc content of the metallized pellet powder product is still very high. Therefore, the application of metallized pellet powder has become a bottleneck for the comprehensive utilization of high-zinc dust and mud in processes such as rotary hearth furnaces and rotary kilns.

[0003] Therefore, it is necessary to develop a technology that can comprehensively treat high-zinc metallurgical dust and mud to solve the process bottleneck of the existing rotary hearth furnace and rotary kiln in treating high-zinc metallurgical dust and mud. Summary of the invention

[0004] In view of the problems of the prior art, the purpose of the present invention is to provide a process for resource utilization of high-zinc metallurgical dust and sludge, which connects the rotary hearth furnace process with the artificial stone manufacturing process, utilizes the rotary hearth furnace process to convert the valuable metals in the high-zinc metallurgical dust and sludge into metallized pellet products, and uses the low-quality metallized pellet powder produced by the rotary hearth furnace as a raw material to be added to the artificial stone manufacturing process, and manufactures high-quality artificial stone, thereby realizing the comprehensive utilization of high-zinc metallurgical dust and sludge.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] The present invention provides a high-zinc metallurgical dust and mud resource utilization process, comprising the following steps:

[0007] S1, mixing high zinc metallurgical dust, a binder, a reducing agent and water to obtain a mixture;

[0008] S2, after forming and drying the mixed material, sending it into a rotary hearth furnace for reduction roasting to generate zinc-containing fume, metallized pellets, and metallized pellet powder;

[0009] S3, the metallized pellet powder is added as a raw material into an artificial stone manufacturing process to obtain artificial stone.

[0010] Preferably, in the step S1, the Zn content in the high-zinc metallurgical sludge is 0.5-35%.

[0011] Preferably, in step S1:

[0012] In the mixture, the mass proportion of the binder is 1-6%, and the mass proportion of the water is 10-15%;

[0013] In the step S1, 2-18% of a reducing agent is added during the mixing process; the reducing agent is selected from one or both of carbon powder and CDQ powder.

[0014] Preferably, the process of step S2 is as follows:

[0015] The mixed material enters a molding machine, is molded through a molding process to obtain pellets, and the molded pellets enter a dryer for drying; the dried pellets enter a rotary hearth furnace for reduction roasting to generate zinc-containing flue gas, metallized pellets, and metallized pellet powder; the zinc-containing flue gas is collected after dust removal to obtain secondary zinc oxide powder, and the secondary zinc oxide powder enters a zinc smelting process; the metallized pellets enter a steelmaking or ironmaking process.

[0016] Preferably, in step S2, during the reduction roasting process, the temperature of the high temperature zone of the rotary hearth furnace is 1280-1380° C., and the reduction roasting time is 6-15 min.

[0017] Preferably, the mass percentage compositions of the metallized pellets and metallized pellet powder are as follows: 30-70% Fe, 0.01-5% C, 1-35% Si, 1-35% Ca, 0.001-5% Mn, <0.5S, <3% P.

[0018] Preferably, in step S3, the artificial stone manufacturing process includes mixing, molding, laminating, drying, and polishing steps;

[0019] Preferably, in step S3, the amount of the metallized pellet powder added is 3-19% of the total amount of raw materials.

[0020] Preferably, in step S3, the mass percentage composition of the artificial stone is as follows: 15-40% CaO, 31-70% SiO2, 3-15% Al2O3, 0.3-5% Fe2O3, and 0.3-8% TiO2.

[0021] Preferably, in step S3, the Mohs strength of the artificial stone is greater than level 6.

[0022] The high-zinc metallurgical dust and mud resource utilization process of the present invention also has the following beneficial effects:

[0023] 1. The present invention solves the process bottleneck of the existing rotary hearth furnace and rotary kiln for treating high-zinc metallurgical dust and mud. By combining the rotary hearth furnace process with the artificial stone manufacturing process, the low-quality metallized pellet powder produced by the rotary hearth furnace is directly or through the grinding and magnetic separation process into the artificial stone manufacturing process, and the metallized pellet powder that cannot be used is made into high-quality artificial stone, which comprehensively utilizes the products of the rotary hearth furnace process, thereby comprehensively utilizing the high-zinc metallurgical dust and mud.

[0024] 2. The present invention utilizes a rotary hearth furnace process to convert valuable metals in high-zinc metallurgical dust into metal products, and utilizes an artificial stone manufacturing process to convert low-quality components of high-zinc metallurgical dust into high-quality artificial stone products, thereby making comprehensive use of the valuable components of metallurgical dust. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0026] Figure 1 This is a schematic diagram of the process for resource utilization of high-zinc metallurgical dust and sludge according to Example 1 of the present invention;

[0027] Figure 2 This is a schematic diagram of the process for resource utilization of high-zinc metallurgical dust and sludge according to Example 2 of the present invention. DETAILED DESCRIPTION

[0028] In order to better understand the above technical solution of the present invention, the technical solution of the present invention is further described below in conjunction with embodiments.

[0029] The present invention can solve the process bottleneck of the existing rotary hearth furnace and rotary kiln processing process for high-zinc metallurgical dust and mud. By combining the rotary hearth furnace process with the artificial stone manufacturing process, the low-quality metallized pellet powder produced by the rotary hearth furnace is directly or through the grinding and magnetic separation process into the artificial stone manufacturing process, and the metallized pellet powder that cannot be used is made into high-quality artificial stone, and the metallized pellet powder product of the rotary hearth furnace process is comprehensively utilized, thereby comprehensively utilizing the high-zinc metallurgical dust and mud.

[0030] Combination Figure 1 , Figure 2 As shown, the high-zinc metallurgical dust and mud resource utilization process provided by the present invention comprises the following steps:

[0031] S1, mixing high zinc metallurgical dust, a binder, a reducing agent and water to obtain a mixture;

[0032] This step is a batching process. High zinc metallurgical dust is quantitatively discharged from a silo and mixed with a quantitative reducing agent and a binder in a mixer. During the mixing process, about 10-15% of water can be added. The raw materials are mixed uniformly by the mixer to obtain a mixed material. The components of the high zinc metallurgical dust used are as follows: 0.5-35% Zn, 20-65% Fe, 0.1-35% C, 1-35% Si, 1-35% Ca, 0.001-5% Mn, <0.1S, <3% P, 0.3-8% TiO2; in a preferred embodiment, the Zn content in the high zinc metallurgical dust can be 5-35% Zn.

[0033] In the above mixture, the mass proportion of the binder is 1-6% for sufficient dezincification, and the mass proportion of the reducing agent is 2-18%. The reducing agent can be one or two of carbon powder and CDQ powder, or other reducing agents.

[0034] S2, after forming and drying the mixed material, sending it into a rotary hearth furnace for reduction roasting to generate zinc-containing fume, metallized pellets, and metallized pellet powder;

[0035] In this step, the mixture enters a forming machine and is formed into pellets through a forming process. The forming process can be formed by a pellet press or a disc pelletizer. The formed pellets enter a dryer for drying, for example, they can be dried by a chain grate or a mesh belt dryer. The dried pellets enter the furnace of a rotary hearth furnace for reduction roasting, and after high-temperature reduction, zinc-containing flue gas, metallized pellets, and metallized pellet powder are generated; zinc, potassium, sodium, and chlorine in high-zinc metallurgical dust enter the flue gas of the rotary hearth furnace and are collected to form zinc-containing flue gas. The zinc-containing flue gas is collected after dust removal to obtain secondary zinc oxide powder, and the secondary zinc oxide powder enters the zinc smelting process; the metallized pellets can enter the steelmaking or ironmaking process, and the metal products obtained are cast iron, pig iron, or molten steel.

[0036] In the above-mentioned reduction roasting process, for high-zinc metallurgical dust, the reduction roasting temperature and roasting time are increased to ensure that all the metallic zinc formed after roasting enters the flue gas in the form of steam; in the specific scheme, the temperature of the high temperature zone of the rotary hearth furnace is 1280-1380°C, and the reduction roasting time is 6-15 minutes.

[0037] The metallization rate of the metallized pellets after reduction roasting reaches 20-96%; the mass percentage compositions of the metallized pellets and metallized pellet powder are as follows: 30-70% Fe, 0.01-5% C, 1-35% Si, 1-35% Ca, 0.001-5% Mn, <0.5S, <3% P.

[0038] S3, the metallized pellet powder is added as a raw material into an artificial stone manufacturing process to obtain artificial stone.

[0039] This step is the artificial stone manufacturing process. The metallized pellet powder is used as a raw material and mixed with other raw materials such as marble crushed stone, quartz sand, stone powder, filler, etc., and the artificial stone product is obtained through mixing, molding, laminating, drying, and polishing. In the above process, the amount of metallized pellet powder added is 3-19% of the total amount of raw materials.

[0040] The mass percentage composition of the artificial stone obtained above is as follows: 15-40% CaO, 31-70% SiO2, 3-15% Al2O3, 0.3-5% Fe2O3, 0.3-8% TiO2, and the Mohs strength of the artificial stone is greater than level 6.

[0041] The high-zinc metallurgical sludge resource utilization process of the present invention is further introduced below with reference to specific examples.

[0042] Example 1

[0043] Combination Figure 1 As shown, the resource utilization process of high-zinc metallurgical dust and mud in this embodiment is as follows:

[0044] High zinc metallurgical dust 1, binder 2 and reducing agent 3 enter the mixer 4 from the raw material silo and are mixed evenly. The binder mass accounts for 1-6%, the reducing agent mass accounts for 2-18%, and the reducing agent can be selected from one or two of carbon powder and CDQ powder, or other reducing agents; 10-15% of water 5 can be added during the mixing process of the mixer. The mixed mixture enters the molding machine 6 and is formed through a molding process; the mixed raw materials can be formed by ball pressing machine or disc ball making machine. The formed materials enter the dryer 7 for drying. The drying process can be dried by a chain grate machine or a mesh belt dryer.

[0045] The dried material enters the rotary hearth furnace 8 for reduction roasting, and generates secondary zinc oxide powder 9, metallized pellets 10 and metallized pellet powder 11 through high temperature reduction reaction. The composition range of the obtained metallized pellets and metallized pellet powder is: 30-70% Fe, 0.01-5% C, 1-35% Si, 1-35% Ca, 0.001-5% Mn, <0.5S, <3% P. Harmful impurities in high-zinc metallurgical dust and mud enter the flue gas of the rotary hearth furnace and are collected to become secondary zinc oxide powder 9 products, and enter the zinc smelting process 12.

[0046] The roasted metallized pellets 10 enter the blast furnace ironmaking process 13, and the composition range of the obtained molten iron is: 90-99.8% Fe, 0.01-12% C, 0.001-5% Si, 0.001-3% Mn, <0.1S, <3%P.

[0047] The calcined metallized pellet powder enters the artificial stone manufacturing process 14. The composition range of the artificial stone finally produced is: 15-40% CaO, 31-70% SiO2, 3-15% Al2O3, 0.3-5% Fe2O3, 0.3-8% TiO2; the Mohs strength of the artificial stone is greater than level 6.

[0048] Example 2

[0049] Combination Figure 2 As shown, the difference between this embodiment and embodiment 1 is that the process of manufacturing artificial stone from metallized pellet powder is described in detail. The resource utilization process of high zinc metallurgical dust and mud in this embodiment is as follows:

[0050] High zinc metallurgical dust 1, binder 2 and reducing agent 3 enter the mixer 4 from the raw material silo and are mixed evenly. The binder mass accounts for 1-6% and the reducing agent mass accounts for 2-18%; 10-15% of water 5 can be added during the mixing process of the mixer. The mixed mixture enters the molding machine 6 and is formed through a molding process; the mixed raw materials can be formed by a ball press or a disc ball making machine. The formed pellets enter the dryer 7 for drying. The drying process can be carried out by a chain grate machine or a mesh belt dryer.

[0051] The dried pellets are placed in a rotary hearth furnace 8 for reduction roasting, and are subjected to high temperature reduction reaction to generate secondary zinc oxide powder 9, metallized pellets 10, and metallized pellet powder 11. The composition range of the obtained metallized pellets and metallized pellet powder is: 30-70% Fe, 0.01-5% C, 1-35% Si, 1-35% Ca, 0.001-5% Mn, <0.5S, <3% P. Harmful impurities in high-zinc metallurgical dust and mud enter the flue gas of the rotary hearth furnace and are collected to become secondary zinc oxide powder 9 products, which enter the zinc smelting process 12.

[0052] The roasted metallized pellets 10 enter the blast furnace ironmaking process 13, and the composition range of the obtained molten iron is: 90-99.8% Fe, 0.01-12% C, 0.001-5% Si, 0.001-3% Mn, <0.1S, <3%P.

[0053] The calcined metallized pellet powder 11 enters the artificial stone manufacturing process 14, where the metallized pellet powder is mixed with other raw materials such as marble crushed stone, quartz sand, stone powder, filler, etc. as raw materials, and the proportion of metallized pellet powder is 3-19%. The artificial stone process includes mixing 141, molding 142, coating 143, drying 144, polishing 145 and other artificial stone production processes. The composition range of artificial stone is: 15-40% CaO, 31-70% SiO2, 3-15% Al2O3, 0.3-5% Fe2O3, 0.3-8% TiO2; the Mohs strength of artificial stone is greater than level 6.

[0054] In summary, the high-zinc metallurgical dust and sludge resource utilization process of the present invention combines the rotary hearth furnace process with the artificial stone manufacturing process. The low-quality metallized pellet powder produced by the rotary hearth furnace is directly or through a grinding and magnetic separation process. The metallized pellet powder that cannot be used is made into high-quality artificial stone, and the products of the rotary hearth furnace process are comprehensively utilized, thereby comprehensively utilizing the high-zinc metallurgical dust and sludge.

[0055] Those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. As long as they are within the spirit of the present invention, any changes or modifications to the above embodiments will fall within the scope of the claims of the present invention.

Claims

1. A process for resource utilization of high-zinc metallurgical dust and mud, characterized in that: The following steps are involved: S1, mixing high zinc metallurgical dust, a binder, a reducing agent and water to obtain a mixture; S2, after forming and drying the mixed material, sending it into a rotary hearth furnace for reduction roasting to generate zinc-containing fume, metallized pellets, and metallized pellet powder; S3, the metallized pellet powder is added as a raw material into an artificial stone manufacturing process to obtain artificial stone.

2. The high-zinc metallurgical dust and sludge resource utilization process according to claim 1 is characterized in that: In the step S1, the Zn content in the high-zinc metallurgical sludge is 0.5-35%.

3. The high-zinc metallurgical dust and sludge resource utilization process according to claim 1 is characterized in that: In step S1: In the mixture, the mass proportion of the binder is 1-6%, the mass proportion of the reducing agent is 2-18%, and the mass proportion of the water is 10-15%; During the mixing process, 2-18% of a reducing agent is added; the reducing agent is selected from one or both of carbon powder and CDQ powder.

4. The high-zinc metallurgical dust and sludge resource utilization process according to claim 1 is characterized in that: The process of step S2 is as follows: The mixed material enters a molding machine, is molded through a molding process to obtain pellets, and the molded pellets enter a dryer for drying; the dried pellets enter a rotary hearth furnace for reduction roasting to generate zinc-containing flue gas, metallized pellets, and metallized pellet powder; the zinc-containing flue gas is collected after dust removal to obtain secondary zinc oxide powder, and the secondary zinc oxide powder enters a zinc smelting process; the metallized pellets enter a steelmaking or ironmaking process.

5. The high-zinc metallurgical dust and sludge resource utilization process according to claim 1 is characterized in that: In step S2, the temperature of the high temperature zone of the rotary hearth furnace is 1280-1380° C., and the reduction roasting time is 6-15 minutes.

6. The high-zinc metallurgical dust and sludge resource utilization process according to claim 4 is characterized in that: The mass percentage compositions of the metallized pellets and metallized pellet powder are as follows: 30-70% Fe, 0.01-5% C, 1-35% Si, 1-35% Ca, 0.001-5% Mn, <0.5S, <3% P.

7. The high-zinc metallurgical dust and mud resource utilization process according to claim 1 is characterized in that: In step S3, the artificial stone manufacturing process includes mixing, molding, coating, drying and polishing steps.

8. The high-zinc metallurgical dust and sludge resource utilization process according to claim 1 is characterized in that: In the step S3, the amount of the metallized pellet powder added is 3-19% of the total amount of the raw materials.

9. The high-zinc metallurgical dust and sludge resource utilization process according to claim 1 is characterized in that: In step S3, the mass percentage composition of the artificial stone is as follows: 15-40% CaO, 31-70% SiO2, 3-15% Al2O3, 0.3-5% Fe2O3, and 0.3-8% TiO2.

10. The high-zinc metallurgical dust and sludge resource utilization process according to claim 1, characterized in that: In step S3, the Mohs strength of the artificial stone is greater than level 6.

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