Metallurgical charge covering agent prepared from water slag micro-powder and coke oven dust and its preparation method

Abstract

This invention belongs to the field of iron and steel metallurgy technology, specifically relating to a metallurgical furnace charge covering agent prepared from blast furnace slag powder and coke oven dust, and its preparation method. This invention, by mixing blast furnace slag powder and coke oven dust and pressing it into granular covering agent, not only improves the efficiency of solid waste recycling within the metallurgical system but also reduces production costs in the metallurgical production process. It is a beneficial supplement and an inevitable trend in realizing the recycling of metallurgical solid waste.

Description

Technical Field

[0001] This invention belongs to the field of iron and steel metallurgy technology, specifically relating to a metallurgical furnace charge covering agent prepared from water slag powder and coke oven dust, and its preparation method. Background Technology

[0002] Blast furnace slag, a molten material mainly composed of calcium silicate and calcium aluminosilicate, is produced during pig iron smelting in blast furnaces. After water quenching and cooling, it forms granular material with a particle size of approximately 1-10 mm, and is simply referred to as slag or water-quenched slag. Slag powder refers to the material obtained by grinding blast furnace slag, with a particle size generally between 30 and 200 mesh. Currently, slag powder from domestic steel plants is mainly used as an additive in silicate cement, typically at around 10%. According to reports, finely ground blast furnace slag also has some feasibility as a flue gas absorbent for SO2 treatment. Due to the large volume of blast furnace slag produced, expanding the utilization and application channels of slag as solid waste, especially achieving recycling within the metallurgical process, not only reduces production costs within the system but also provides better process options for achieving carbon emission standards.

[0003] Coke oven dust refers to the particulate powder generated during coke oven production. This dust, collected by a dust removal system, typically has a carbon content of 60-90%. After discarding larger particles that can be used directly as coke powder, coke oven dust, especially with a particle size of 10-50 mesh, is currently mainly used as a base material for sintering in LCD systems for recycling. However, due to the fine particle size and low density of the coke oven dust, a high proportion is absorbed by the sintering system, resulting in low recycling efficiency.

[0004] Therefore, seeking more effective application channels for blast furnace slag and coke oven dust to achieve solid waste recycling is an urgent requirement in metallurgical production. Summary of the Invention

[0005] To achieve the above objectives, this invention mixes blast furnace slag powder and coke oven dust and presses them into granular covering agents. This not only improves the efficiency of solid waste recycling within the metallurgical system but also reduces production costs in the metallurgical production process. It is a beneficial supplement and an inevitable trend for realizing the recycling of metallurgical solid waste.

[0006] A metallurgical furnace charge covering agent prepared from water slag powder and coke oven dust includes: water slag powder, coke oven dust, binder, and water; The coke oven dust comprises 10-30% of the mass of the slag powder, the binder comprises 5-25% of the mass of the slag powder, and the water comprises 3-5% of the total mass of the slag powder and binder. If the coke oven dust content is too low, the insulation performance will be insufficient, requiring an increase in the amount of covering agent to compensate for the insulation defect; if the coke oven dust content is too high, it may affect the quality of the molten steel, leading to a prolonged external insulation time.

[0007] Furthermore, the coke oven dust contains 70-90 wt% C, with the remainder being ash and residual non-metallic oxides.

[0008] The water slag powder comprises the following raw materials in the following mass percentages: CaO 25~55%, SiO2 20~45%, Al2O3 3~20%, MgO 1~15%, with the balance being residual metal oxides.

[0009] The particle size of the water slag powder and coke oven dust is 30-200 mesh. If the particle size is less than 30 mesh, the particles are not easy to form and the cost increases; if the particle size is greater than 200 mesh, the water slag powder easily absorbs moisture.

[0010] The adhesive is a starch adhesive.

[0011] Preferably, the binder is corn starch paste.

[0012] The metallurgical furnace charge covering agent is used in steelmaking ladles and refining ladles.

[0013] The preparation method of the above-mentioned metallurgical furnace charge covering agent includes the following steps: (1) Mix water slag powder, coke oven dust, binder and water, and stir evenly to obtain the initial raw materials; (2) Add the blank obtained in step (1) into the pellet mold and press it in the molding machine to obtain the initial pellets; (3) The initial particles obtained in step (2) are dried, slowly cooled and bagged to obtain a metallurgical furnace charge covering agent.

[0014] Preferably, after the water slag powder, coke oven dust and binder mentioned in step (1) are fully mixed, they are left to stand at room temperature for more than 2 hours, preferably 10-24 hours.

[0015] Preferably, the cross-sectional shape of the initial product pressed by the molding machine in step (2) is elliptical, rectangular, or trapezoidal. The pressing conditions are: pressure ≥ 20KN, pressing time ≤ 15s; more preferably, the pressing pressure is 30~50KN, and the pressing time is 3~5s.

[0016] Preferably, the drying temperature in step (3) is 100~300℃, more preferably 130~180℃; the drying time is 15~30min.

[0017] Preferably, the slow cooling time in step (3) is 3 to 5 minutes, slow cooling to room temperature.

[0018] The metallurgical furnace charge covering agent of the present invention is in granular form.

[0019] The technical features and beneficial effects of this invention are as follows: 1. The metallurgical furnace charge covering agent provided by the present invention uses metallurgical solid waste as raw material, realizes the recycling of metallurgical solid waste, and significantly reduces the metallurgical production cost.

[0020] 2. The metallurgical furnace charge covering agent provided by this invention has a simple preparation process without reducing product performance. Detailed Implementation

[0021] The present invention will be further described below with reference to specific embodiments, but is not limited thereto. Any aspects not described in detail herein are existing technologies in the art.

[0022] Example 1 A process and method for preparing a metallurgical furnace charge covering agent from water slag powder and coke oven dust includes: coke oven dust, water slag powder, binder and water; The mass of the coke oven dust is 30% of the water slag powder, and the water slag powder and coke oven dust include the following raw materials by mass percentage: CaO 33%, SiO2 28%, Al2O3 5%, MgO 1.5%, C 20%, with the remainder being residual metal or non-metal oxides and ash. The binder is corn starch paste, and the mass of the binder is 5% of the mass of the water slag powder; the mass of the water is 3% of the total mass of the water slag powder and the binder.

[0023] The preparation method of the above-mentioned metallurgical furnace charge covering agent includes the following steps: (1) Place the water slag powder, binder and water into a mixer and stir and mix them. After stirring for 25 minutes, let it stand at room temperature for 10 hours to obtain the initial raw materials.

[0024] (2) The initial raw materials are transported to the pellet mill hopper via belt. The initial raw materials in the pellet mill hopper are poured into the pellet mold and pressed in the molding machine to obtain initial pellets. The pelleting pressure is 22KN and the pressing time is 5s. The obtained initial pellets are put into the dryer for drying. The drying temperature is set at 180℃ and the drying time is 17 minutes. After drying, they are placed in the slow cooler for slow cooling. The slow cooling time is set at 3 minutes. Then they are put into customized packaging bags to form the final qualified covering agent product.

[0025] The covering agent prepared in this embodiment was used on a 120-ton LF refining steel ladle. Compared with traditional carbonized rice husk, the temperature difference in heat preservation was within 10-20℃. After the covering agent prepared in this embodiment was added to the surface of the steel ladle, the covering agent quickly slags, forms a crust, and spreads. The slag crust has better spreadability than traditional carbonized rice husk products.

[0026] Example 2 A process and method for preparing a metallurgical furnace charge covering agent from water slag powder and coke oven dust includes the following raw materials: water slag powder, coke oven dust, binder and water; The mass of the coke oven dust is 18% of the water slag powder, and the water slag powder and coke oven dust include the following raw materials by mass percentage: CaO 31%, SiO2 24%, Al2O3 8%, MgO 2.5%, C 12%, with the remainder being residual metal or non-metal oxides and ash. The binder is corn starch paste, and the mass of the binder is 7% of the mass of the water slag powder; the mass of the water is 4.0% of the total mass of the water slag powder and the binder.

[0027] The preparation method of the above-mentioned metallurgical furnace charge covering agent includes the following steps: (1) Place the water slag powder, binder and water into a mixer and stir and mix them. After stirring for 20 minutes, let the mixed raw materials stand at room temperature for 16 hours to obtain the initial raw materials.

[0028] (2) The initial raw materials are transported to the pellet mill hopper via belt. The initial raw materials in the pellet mill hopper are poured into the pellet mold and pressed to obtain initial pellets. The pelleting pressure is 30KN and the pressing time is 5s. The obtained initial pellets are then put into a dryer for drying. The drying temperature is set at 130℃ and the drying time is 21 minutes. After drying, the pellets are placed in a slow cooler for slow cooling. The slow cooling time is set at 3 minutes. Then, the pellets are put into customized packaging bags to form the final qualified covering agent product.

[0029] The covering agent prepared in this embodiment was used on a 120-ton RH refining ladle. Compared with traditional carbonized rice husks, the temperature difference in heat preservation was within 10-15℃. After the covering agent prepared in this embodiment was added to the surface of the ladle, the covering agent quickly slags, forms a crust, and spreads. The slag crust has better spreadability than traditional carbonized rice husk products.

Claims

1. A metallurgical furnace charge covering agent prepared from water slag powder and coke oven dust, characterized in that, include: Water slag powder, coke oven dust, binder, water; The coke oven dust is 10-30% of the mass of the water slag powder, the binder is 5-25% of the mass of the water slag powder, and the water is 3-5% of the total mass of the water slag powder and binder.

2. The metallurgical furnace charge covering agent according to claim 1, characterized in that, The coke oven dust contains 70-90 wt% C, with the remainder being ash and residual non-metallic oxides.

3. The metallurgical furnace charge covering agent according to claim 1, characterized in that, The water slag powder comprises the following raw materials in the following mass percentages: CaO 25~55%, SiO2 20~45%, Al2O3 3~20%, MgO 1~15%, with the balance being residual metal oxides.

4. The metallurgical furnace charge covering agent according to claim 1, characterized in that, The particle size of the water slag powder and coke oven dust is 30-200 mesh.

5. The metallurgical furnace charge covering agent according to claim 1, characterized in that, The adhesive is a starch adhesive; Preferably, the binder is corn starch paste.

6. The metallurgical furnace charge covering agent according to claim 1, characterized in that, The metallurgical furnace charge covering agent is used in steelmaking ladles and refining ladles.

7. A method for preparing a metallurgical furnace charge covering agent as described in any one of claims 1 to 6, characterized in that, The steps include the following: (1) Mix water slag powder, coke oven dust, binder and water, and stir evenly to obtain the initial raw materials; (2) Add the blank obtained in step (1) into the pellet mold and press it in the molding machine to obtain the initial pellets; (3) The initial particles obtained in step (2) are dried, slowly cooled and bagged to obtain a metallurgical furnace charge covering agent.

8. The preparation method according to claim 7, characterized in that, In step (2), the pressing pressure is ≥20KN and the pressing time is ≤15s; Preferably, the pressing pressure is 30~50KN and the pressing time is 3~5s.

9. The preparation method according to claim 7, characterized in that, The drying temperature in step (3) is 100~300℃, preferably 130~180℃.

10. The preparation method according to claim 7, characterized in that, The drying time is 15-30 minutes; The slow cooling time is 3-5 minutes, until the temperature reaches room temperature.