Support frame for sintering high-proportion concentrate as well as preparation and use methods of support frame

Abstract

The invention relates to a support frame for sintering high-proportion concentrate as well as a preparation method and a use method of the support frame. The support frame comprises the following raw materials in parts by weight: 45-60 parts of sintered return mine, 20-30 parts of oily sludge, 6-12 parts of desulfurized fly ash, 5-10 parts of a pore forming agent and 3-6 parts of a cold setting binder. Compared with the prior art, the invention has the following beneficial effects: 1) the caking property of the oily sludge is utilized to reduce a cold setting binder, the desulfurized fly ash is adopted as a calcium flux to realize complete consistency of chemical components of the support frame and the sintered ore, and efficient resource utilization of the oily sludge and the desulfurized fly ash is realized; and 2) the pore-forming agent is decomposed and exhausted at high temperature to form holes with different diameters, so that the air flow on the sintering trolley is uniformly distributed, and the influence of non-uniform air flow formed near the support frame on the sintering process is reduced.

Description

Technical Field

[0001] This invention belongs to the field of sintering technology, and specifically relates to a support frame for high-proportion concentrate sintering and its preparation and use methods. Background Technology

[0002] Low-carbon thick-layer sintering technology can significantly improve sintering productivity, enhance sinter quality, and reduce sintering fuel consumption, making it an important measure for energy conservation and emission reduction in the steel industry. However, as the layer thickness increases, the permeability of the layer gradually deteriorates. When the layer reaches a certain thickness, permeability deteriorates sharply, leading to a decrease in sintering speed, an increase in negative pressure, a significant increase in air leakage, uneven sintering between the upper and lower parts, and a decrease in yield. Improving the permeability of the layer is a key factor in maximizing the advantages of thick-layer sintering.

[0003] During the sintering process, the sintered ore in the upper region exerts a significant load on the combustion zone, causing poor permeability of the sinter bed in the lower region and thus affecting sintering performance. This effect is particularly pronounced when the proportion of magnetite concentrate in the lower region of the sinter bed is high. To improve the permeability of the sinter bed under gravity, support-supported sintering technology has been developed. Examples include "Sinter Bed Load Reduction Device, Sintering Machine Using the Device and Sintering Method" (CN101694349B), "Sintering Machine Support" (CN201892422U), and "Sintering Machine Support" (CN201892422U). Actual production testing has shown that using this method requires significant modifications to the sintering support beams at the head and tail of the sintering machine, the height of the single-tooth roller, and the bottom material leveling device at the head, resulting in high modification costs. In addition, the unloading device in this method is prone to wear and tear, and replacing the device requires machine shutdown, resulting in a large amount of maintenance and replacement labor and high costs. Moreover, the unloading device itself occupies space on the sintering trolley, which significantly reduces the output of sintered ore.

[0004] The production method for improving the permeability of thick material layer sintering (CN110629018B) and the flexible homogeneous sintering process for ultra-thick material layer (CN117286333A) have deviations from the composition of sintered ore, which will affect the fluctuation of the final sintered ore composition. They also have defects such as poor load reduction effect and high cost. Summary of the Invention

[0005] The purpose of this invention is to provide a support frame for high-proportion concentrate sintering and its preparation and use method. Using sintering return ore, desulfurization ash, and oily sludge from converters as raw materials, and adding appropriate pore-forming agents and cold-setting binders, a porous sintering support frame is prepared, which improves the permeability of the entire material layer. The operation is simple and easy, and does not affect the quality of sintered ore.

[0006] To achieve the above objectives, the present invention employs the following technical solution: A support frame for high-proportion concentrate sintering comprises the following raw materials by weight: 45-60 parts of sintering return ore, 20-30 parts of oily sludge, 6-12 parts of desulfurization ash, 5-10 parts of pore-forming agent, and 3-6 parts of cold-curing binder.

[0007] Furthermore, the pore-forming agent is one or more of waste polypropylene foam, wood chips, and waste cardboard boxes. The pore-forming agent has two particle sizes: one with a particle size of 9–16 mm and the other with a particle size of 3–8 mm.

[0008] A method for preparing a support frame for high-proportion concentrate sintering includes the following steps: 1) Prepare mixture A by thoroughly mixing a portion of sintered return ore, a portion of oily sludge, a portion of desulfurization ash, and a portion of cold-curing binder according to the composition of sintered ore, with a mixing time of 5 to 10 minutes; 2) Prepare mixture B by thoroughly mixing a portion of sintered return ore, a portion of oily sludge, a portion of desulfurization ash, a pore-forming agent with a particle size range of 9-16 mm, and a portion of cold-curing binder according to the composition of sintered ore, with a mixing time of 10-15 min; 3) According to the composition of sintered ore, the remaining sintered return ore, oily sludge, desulfurization ash, pore-forming agent with a particle size range of 3-8mm, and cold-curing binder are thoroughly mixed for 15-20 minutes to prepare mixture C; 4) Prepare a frustum-shaped mold with a bottom circle diameter R of 200-500 mm, a top circle diameter r of 50-100 mm, and a height h of 400-700 mm; 5) Load mixture A into a frustum-shaped mold and repeatedly press it under a pressure range of 2.3 to 3.5 t / cm. After compaction, the thickness h1 of mixture A is 0.1h to 0.3h. 6) Load mixture B onto mixture A and repeatedly press it under a pressure range of 2.0 to 3.0 t / cm. After compaction, the thickness h2 of mixture B is 0.3h to 0.5h. 7) Load mixture C onto mixture B and repeatedly press it under a pressure range of 1.5 to 2.3 t / cm. After compaction, the thickness h3 of mixture C is 0.2h to 0.4h. 8) Then, after demolding, drying and firing, the finished support frame is obtained. The drying temperature is 120-150℃ and the time is 0.5-1.5h. The firing temperature is 1100-1200℃ and the time is 0.5-1.0h.

[0009] A method for using a support frame for sintering high-proportion magnetic concentrate, wherein the high-proportion magnetic concentrate refers to iron concentrate in which the mass fraction of iron-containing raw materials is ≥70%, and the specific method includes: After the base material is laid and before the sintering mixture is fed from the roller feeder, the support frames are placed on the base material via a conveying device and evenly distributed along the transverse direction of the sintering trolley. When the width of the sintering trolley is less than 3.5m, 2-3 support frames are arranged on the sintering trolley; when the width of the sintering trolley is 4-5.5m, 3-5 support frames are arranged on the sintering trolley; when the width of the sintering trolley is greater than 5.5m, 5-7 support frames are arranged on the sintering trolley. When the iron concentrate accounts for ≥70% and <80% of the iron-containing raw material mass fraction, the height of the support frame h = 0.3-0.5H4; when the iron concentrate accounts for ≥80% and <90% of the iron-containing raw material mass fraction, the height of the support frame h = 0.4-0.6H4; when the iron concentrate accounts for more than 90% of the iron-containing raw material mass fraction, the height of the support frame h = 0.5-0.8H4, where H4 is the thickness of the sintering material layer.

[0010] Cold-curing adhesives are one or more of epoxy resin adhesives, polyurethane adhesives, and water-based adhesives.

[0011] Compared with the prior art, the beneficial effects of the present invention are: 1) The adhesive properties of oily sludge can reduce the need for cold-curing binders. Desulfurization ash can be used as a calcium flux to ensure that the chemical composition of the support frame is completely consistent with that of the sintered ore, thus achieving efficient resource utilization of oily sludge and desulfurization ash.

[0012] 2) The pore-forming agent is decomposed and exhausted at high temperature to form pores of different diameters, which plays a role in the uniform distribution of airflow on the sintering trolley and reduces the impact of uneven airflow near the support frame on the sintering process. Attached Figure Description

[0013] Figure 1 This is a cross-sectional schematic diagram of the support frame placement position of the present invention.

[0014] In the diagram: 1-Sintered material, 2-Mixed material C, 3-Mixed material B, 4-Mixed material A. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of this invention clearer, the specific implementation methods of this invention will be further described below in conjunction with the embodiments. The following embodiments are used to specifically illustrate the content of this invention. These embodiments are only general descriptions of the content of this invention and do not limit the content of this invention.

[0016] The cross-section of the support frame placement position of the present invention is as follows Figure 1 As shown.

[0017] Example 1: A support frame for high-proportion concentrate sintering, the raw materials of which, by weight (dry basis), consist of 60 parts of sintering return ore, 20 parts of oily sludge, 12 parts of desulfurization ash, 5 parts of pore-forming agent, and 3 parts of cold-curing binder. Mixture A4 is prepared by thoroughly mixing a portion of sintered return ore, a portion of oily sludge, a portion of desulfurization ash, and a portion of cold-curing binder for 10 minutes. Mixture B3 is prepared by thoroughly mixing a portion of sintered return ore, a portion of oily sludge, a portion of desulfurization ash, a pore-forming agent with a particle size of 16 mm, and a portion of cold-curing binder according to the composition of the sintered ore produced, for 15 minutes. Mixture C2 is prepared by thoroughly mixing the remaining sintered return ore, oily sludge, desulfurization ash, a pore-forming agent with a particle size of 8 mm, and cold-curing binder according to the composition of the sintered ore produced, for 20 minutes. A frustum-shaped mold with a trapezoidal cross-section is prepared, with a bottom diameter R ranging from 500 mm, a top diameter r ranging from 100 mm, and a height h ranging from 700 mm. Mixture A is loaded into the frustum-shaped mold and repeatedly pressed under a pressure of 3.5 t / cm until the thickness of the compacted mixture A4 is 210 mm. mm; Mixture B3 is loaded onto mixture A4 and repeatedly pressed under a pressure of 3.0 t / cm until the thickness of mixture B3 is 350 mm; Mixture C2 is loaded onto mixture B3 and repeatedly pressed under a pressure of 2.3 t / cm until the thickness of mixture C2 is 140 mm; The support frame is demolded, dried, and fired to obtain the finished support frame. The drying temperature range is 150℃ for 1.5 h, and the firing temperature is 1200℃ for 1.0 h.

[0018] After the base material is laid and before the sintering mixture is fed from the roller feeder, the support frames are placed on the base material via a conveying device and evenly distributed along the transverse direction of the sintering trolley. When the width of the sintering trolley is 4m, 5 support frames are arranged on the sintering trolley. When the iron concentrate accounts for 91% of the iron-containing raw material mass fraction and the sintering material layer thickness is 1000 mm, the height of the support frame h = 700 mm.

[0019] After the application of this invention, the sintering utilization coefficient increased from 1.283 t / hm. 2 Increased to 1.566 t / hm 2 Solid fuel consumption decreased from 48.3 kg / t to 38.6 kg / t; the sinter drum strength increased from 77.63% to 83.28%, and the reducibility increased from 82.62% to 86.68%.

[0020] Example 2: A support frame for high-proportion concentrate sintering, by weight (dry basis), comprises 45 parts sintering return ore, 30 parts oily sludge, 12 parts desulfurization ash, 9 parts pore-forming agent, and 4 parts cold-curing binder. Mixture A4 is prepared by thoroughly mixing a portion of sintered return ore, a portion of oily sludge, a portion of desulfurization ash, and a portion of cold-curing binder for 5 minutes. Mixture B3 is prepared by thoroughly mixing a portion of sintered return ore, a portion of oily sludge, a portion of desulfurization ash, a pore-forming agent with a particle size of 9 mm, and a portion of cold-curing binder according to the composition of the sintered ore produced, for 10 minutes. Mixture C2 is prepared by thoroughly mixing the remaining sintered return ore, oily sludge, desulfurization ash, a pore-forming agent with a particle size of 3 mm, and cold-curing binder according to the composition of the sintered ore produced, for 15 minutes. A trapezoidal frustum-shaped mold is prepared with a bottom circle diameter R ranging from 200 mm, a top circle diameter r ranging from 50 mm, and a height h ranging from 400 mm. Mixture A4 is loaded into the frustum-shaped mold and repeatedly pressed under a pressure of 2.3 t / cm until the thickness of mixture A4 after compaction is 40 mm. mm; Mixture B3 is loaded onto mixture A4 and repeatedly pressed under a pressure of 2.0 t / cm until the thickness of mixture B3 is 200 mm; Mixture C2 is loaded onto mixture B3 and repeatedly pressed under a pressure of 1.5 t / cm until the thickness of mixture C2 is 160 mm; The support frame is demolded, dried, and fired to obtain the finished support frame. The drying temperature range is 120℃ for 0.5 h, and the firing temperature is 1100℃ for 0.5 h.

[0021] After the base material is laid and before the sintering mixture is fed from the roller, the support frame is placed on the base material by the conveying device and evenly arranged along the transverse side of the trolley. When the width of the sintering trolley is 3.5m, two support frames are arranged on the sintering trolley. When the thickness of the sintering material layer is 900mm and the iron concentrate accounts for 89% of the iron content of the raw material, the height of the support frame is 400mm.

[0022] After the application of this invention, the sintering utilization coefficient increased from 1.282 t / hm. 2 Increased to 1.466 t / hm 2 Solid fuel consumption decreased from 47.32 kg / t to 42.85 kg / t; the sinter drum strength increased from 77.63% to 83.26%, and the reducibility increased from 81.64% to 83.67%.

[0023] Example 3: A support frame for high-proportion concentrate sintering, by weight (dry basis), comprises 50 parts sintering return ore, 25 parts oily sludge, 10 parts desulfurization ash, 10 parts pore-forming agent, and 5 parts cold-curing binder. Mixture A4 is prepared by thoroughly mixing a portion of sintered return ore, a portion of oily sludge, a portion of desulfurization ash, and a portion of cold-curing binder for 6 minutes. Mixture B3 is prepared by thoroughly mixing a portion of sintered return ore, a portion of oily sludge, a portion of desulfurization ash, a pore-forming agent with a particle size of 9 mm, and a portion of cold-curing binder according to the composition of the sintered ore produced, for 12 minutes. Mixture C2 is prepared by thoroughly mixing the remaining sintered return ore, oily sludge, desulfurization ash, a pore-forming agent with a particle size of 3 mm, and cold-curing binder according to the composition of the sintered ore produced, for 16 minutes. A trapezoidal frustum-shaped mold is prepared with a bottom circle diameter R ranging from 300 mm, a top circle diameter r ranging from 75 mm, and a height h ranging from 500 mm. Mixture A4 is loaded into the frustum-shaped mold and repeatedly pressed under a pressure of 2.3 t / cm until the thickness of mixture A4 after compaction is 50 mm. mm; Mixture B3 is loaded onto mixture A4 and repeatedly pressed under a pressure of 2.0 t / cm until the thickness of mixture B3 is 250 mm; Mixture C2 is loaded onto mixture B3 and repeatedly pressed under a pressure of 1.5 t / cm until the thickness of mixture C2 is 200 mm; The support frame is demolded, dried, and fired to obtain the finished support frame. The drying temperature range is 120℃ for 1 hour, and the firing temperature is 1100℃ for 1 hour.

[0024] After the base material is laid and before the sintering mixture is fed from the roller, the support frame is placed on the base material by the conveying device and evenly arranged along the transverse side of the trolley. When the width of the sintering trolley is 5.5m, 7 support frames are arranged on the sintering trolley. When the thickness of the sintering material layer is 1000 mm and the iron concentrate accounts for 70% of the mass fraction of the iron-containing raw material, the height of the support frame is 500 mm.

[0025] After the application of this invention, the sintering utilization coefficient increased from 1.381 t / hm 2 Increased to 1.505 t / hm 2 Solid fuel consumption decreased from 47.32 kg / t to 39.23 kg / t; the sinter drum strength increased from 78.69% to 85.26%, and the reducibility increased from 81.66% to 84.68%.

[0026] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. In the above embodiments of the present invention, the descriptions of each embodiment have their own emphasis; parts not described in detail in a certain embodiment can be referred to in the relevant descriptions of other embodiments. It should be understood that the disclosed technical content in the several embodiments provided in this application can be implemented in other ways.

Claims

1. A support frame for high-proportion concentrate sintering, characterized in that, Its constituent raw materials, by weight, include: 45-60 parts of sintered return ore, 20-30 parts of oily sludge, 6-12 parts of desulfurization ash, 5-10 parts of pore-forming agent, and 3-6 parts of cold-curing binder.

2. The support frame for high-proportion concentrate sintering according to claim 1, characterized in that, The pore-forming agent is one or more of waste polypropylene foam, wood chips, and waste paper boxes.

3. The support frame for high-proportion concentrate sintering according to claim 1, characterized in that, The pore-forming agent has two particle sizes: one with a particle size of 9–16 mm and the other with a particle size of 3–8 mm.

4. A method for preparing a support frame for high-proportion concentrate sintering as described in any one of claims 1-3, characterized in that, The following methods and steps are included: 1) Thoroughly mix a portion of sintered return ore, a portion of oily sludge, a portion of desulfurization ash, and a portion of cold-cured binder to prepare mixture A; 2) Mix a portion of sintered return ore, a portion of oily sludge, a portion of desulfurization ash, a pore-forming agent with a particle size range of 9-16 mm, and a portion of cold-curing binder thoroughly to prepare mixture B; 3) Thoroughly mix the remaining sintered return ore, oily sludge, desulfurization ash, pore-forming agent with a particle size range of 3-8 mm, and cold-setting binder to prepare mixture C; 4) Prepare a frustum-shaped mold with a bottom circle diameter R of 200-500 mm, a top circle diameter r of 50-100 mm, and a height h of 400-700 mm; 5) Load mixture A into a frustum-shaped mold and repeatedly press it under a pressure range of 2.3 to 3.5 t / cm. After compaction, the thickness h1 of mixture A is 0.1h to 0.3h. 6) Load mixture B onto mixture A and repeatedly press it under a pressure range of 2.0 to 3.0 t / cm. After compaction, the thickness h2 of mixture B is 0.3h to 0.5h. 7) Load mixture C onto mixture B and repeatedly press it under a pressure range of 1.5 to 2.3 t / cm. After compaction, the thickness h3 of mixture C is 0.2h to 0.4h. 8) Then, after demolding, drying and firing, the finished support frame is obtained. The drying temperature is 120-150℃ and the time is 0.5-1.5h. The firing temperature is 1100-1200℃ and the time is 0.5-1.0h.

5. A method of using a support frame for high-proportion concentrate sintering as described in claim 1, characterized in that, Specific methods include: After laying the base material and before the sintering mixture is fed from the roller, place the support frames on the base material and evenly distribute them along the transverse direction of the sintering trolley. When the width of the sintering trolley is less than 3.5m, place 2-3 support frames on the sintering trolley; when the width of the sintering trolley is 4-5.5m, place 3-5 support frames on the sintering trolley; when the width of the sintering trolley is greater than 5.5m, place 5-7 support frames on the sintering trolley. When the iron concentrate accounts for less than 80% of the iron-containing raw material by mass, the height of the support frame h = 0.3-0.5H4; when the iron concentrate accounts for less than 90% of the iron-containing raw material by mass, the height of the support frame h = 0.4-0.6H4; when the iron concentrate accounts for more than 90% of the iron-containing raw material by mass, the height of the support frame h = 0.5-0.8H4, where H4 is the thickness of the sintering material layer.

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