A crucible and method for determining the reactivity of coke-iron oxide coupling

Abstract

This invention relates to a crucible and method for determining the coupling reactivity of coke iron oxides, comprising an upper component and a lower component. The bottom of the upper component is provided with a porous filter layer, and the side of the lower component is provided with multiple through holes. The upper and lower components are interlocked by a concave-convex structure. This invention addresses the current situation where the evaluation indicators for metallurgical coke used in blast furnaces cannot reflect the actual needs of blast furnaces. After implementation, this invention can provide a precise characterization of the quality of blast furnace coke, which can be used to guide production, reduce the operational burden on the ironmaking site, lower the coke ratio, reduce carbon dioxide emissions, increase iron production, and ensure stable blast furnace operation.

Description

Technical Field

[0001] This invention relates to the field of coke performance testing, and specifically to a crucible and method for determining the coupling reactivity of iron oxides in coke. Background Technology

[0002] Coke, as one of the main raw materials in the smelting process, plays a crucial and irreplaceable role in supporting the stable and smooth operation of blast furnaces. Gasification and melting losses of coke in the blast furnace lead to coke deterioration, thus affecting the smelting efficiency; in severe cases, it can result in poor gas and liquid permeability and unsmooth furnace operation. The distortion of blast furnace coke evaluation has become a hot research topic in the industry in recent years. The main reason is that the blast furnace is a black box, and currently there is no suitable device to monitor the high-temperature performance of coke inside the blast furnace in real time. Each company evaluates coke based on its own blast furnace operation conditions and CSR, CRI, and mechanical strength, but these methods cannot fully reflect the actual high-temperature performance requirements of blast furnace coke.

[0003] Currently, the evaluation of coke, whether in production sites or laboratories, is based on the quality and strength of coke after gasification. However, the actual blast furnace interior involves a multiphase reaction of molten iron, iron ore reduction products, coke, carbon dioxide, and water vapor. There is currently no suitable device or method to measure the coupled reaction of coke and iron ore. Summary of the Invention

[0004] The purpose of this invention is to provide a crucible and method for determining the coupling reactivity of coke iron oxides. Addressing the current situation where the evaluation indicators for metallurgical coke used in blast furnaces cannot reflect the actual needs of blast furnaces, this invention will enable precise characterization of the quality of blast furnace coke, guiding production, reducing the operational burden on the ironmaking site, lowering the coke ratio, reducing carbon dioxide emissions, increasing iron production, and ensuring stable blast furnace operation.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A crucible for determining the coupling reactivity of coke iron oxide includes an upper component and a lower component. The bottom of the upper component is provided with a porous filter layer, and the side of the lower component is provided with multiple through holes. The upper component and the lower component are connected by a concave-convex structure.

[0007] The lower component has four through holes.

[0008] The diameter of the through hole is 5-10 mm.

[0009] The diameter of the pores on the porous filter layer of the upper component is 3-4 mm.

[0010] A method for determining the coupling reactivity of coke iron oxides using a crucible for determining the coupling reactivity of coke iron oxides includes the following steps:

[0011] 1) The upper and lower components are bonded together using a high-temperature adhesive; the high-temperature adhesive contains more than 90% Al2O3+SiO2.

[0012] 2) Place the coke and iron ore in layers in the upper part of a specially made crucible with an outer diameter of 20-60mm and a height of 40-80mm (the crucible material is graphite or corundum, which can be placed in the corresponding tube furnace), with the coke in the lower layer and the iron ore in the upper layer; the ratio of coke to iron ore is 1:5-1.

[0013] Coke and iron ore are pre-treated by crushing and screening to ensure that their particle size is between 4mm and 10mm.

[0014] 3) Place the crucible containing the raw materials into the horizontal tube furnace. The through hole of the lower component of the crucible should face the direction of the incoming gas. Design the test regime with reference to the actual conditions of the blast furnace. Under the reducing atmosphere, the iron ore is gradually reduced to metallic iron. As the temperature rises further, the iron ore washes over the coke and flows to the lower component through the pores of the porous filter layer. The atmosphere regime is shown in Table 1.

[0015] Table 1 Temperature and Atmosphere Regimes

[0016]

[0017] The total gas flow rate shall not be less than 2L / min.

[0018] 4) The upper component contains coke, and the lower component contains liquid metal iron and liquid slag. Remove the crucible and air-cool or water-quench it, or let the crucible cool with the furnace.

[0019] 5) After cooling, break the crucible, take out the coke and metallic iron, weigh them, and calculate the weight loss rate. The weight loss rate of coke is the coke-coupled iron oxide coupling reactivity. The lower the coke weight loss rate, the smaller the loss of coke-coupled iron oxide coupling reactivity.

[0020] Compared with existing technologies, the beneficial effects of this invention are:

[0021] The crucible of this invention enables the testing of coupled reactivity of iron oxides in blast furnace coke. It can simulate the reactivity of coke at any location in the blast furnace without the need for an additional complex reactor. The crucible can be placed in any horizontal tube furnace to complete the relevant coupled reactivity tests of iron oxides. Furthermore, the crucible of this invention utilizes a small sample volume, eliminating the need for a large sample preparation process.

[0022] This invention allows for precise simulation of the reaction process of coke in a blast furnace and measurement of its high-temperature reactivity. It provides accurate evaluation indicators for the high-temperature performance of coke, addressing the issue of distorted coke evaluation. Furthermore, it eliminates the need for substantial investment in new equipment; only consumables are required. Therefore, its widespread application is highly feasible. Attached Figure Description

[0023] Figure 1 This is a front view of the crucible of the present invention.

[0024] Figure 2 This is a side view of the crucible of the present invention.

[0025] Figure 3 This is a rear view of the crucible of the present invention.

[0026] Figure 4 This is a top view of the components on the crucible of the present invention.

[0027] Figure 5 The temperature regime and atmosphere regime of this invention.

[0028] In the diagram: 1-upper component, 2-lower component, 3-through hole, 4-hole, 5-porous filter layer. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are merely illustrative and are not intended to limit the present invention.

[0030] The main idea of ​​this invention is to use our designed iron oxide coupling crucible to simulate the actual conditions of a blast furnace, and to carry out a three-phase coupling reaction involving the gas phase, liquid phase (molten iron), and solid phase (iron oxides and coke). Iron ore (natural rich ore, sinter, and pellets) and coke are placed in a specially designed crucible. The metallic iron generated after the reduction of iron oxides, the slag and metallic iron are heated and melted to generate molten iron and liquid slag to wash the coke. The molten iron and slag are separated from the coke through a porous filter layer 5.

[0031] See Figures 1-4 A crucible for determining the coupling reactivity of coke iron oxide includes an upper component 1 and a lower component 2. The bottom of the upper component 1 is provided with a porous filter layer 5, and the side of the lower component 2 is provided with multiple through holes 3. The upper component 1 and the lower component 2 of the crucible are separate and are connected by a concave-convex structure.

[0032] There are 4 through holes 3 on the lower component 1.

[0033] The diameter of through hole 3 is 5-10mm.

[0034] The diameter of the pores 4 on the porous filter layer 5 of the upper component 1 is 3-4 mm.

[0035] Example 1:

[0036] A method for determining the coupling reactivity of coke iron oxides using a crucible for determining the coupling reactivity of coke iron oxides includes the following steps:

[0037] 1) In order to prevent the liquid slag and molten iron from flowing out at the uneven structure due to surface tension and affecting the test results, a high-temperature adhesive is used to bond the upper component 1 and the lower component 2 together; the content of Al2O3+SiO2 in the high-temperature adhesive is greater than 90%.

[0038] The lower component 2 of the crucible has four through holes 3 with a diameter of 5 mm on the side, which are the overall gas inlets inside the crucible, ensuring that the iron ore, coke and gas in the crucible are in a counter-current reactor.

[0039] 2) Place 8g of coke and 32g of iron ore in layers into the upper component 1 of a specially made crucible with an outer diameter of 40mm and a height of 70mm (the crucible material is graphite or corundum), with the coke in the lower layer and the iron ore in the upper layer.

[0040] Coke and iron ore are pre-treated by crushing and screening to ensure that their particle size is between 4mm and 10mm.

[0041] 3) Place the crucible containing the raw materials in a horizontal tube furnace. The through hole of the lower component of the crucible faces the direction of the incoming gas. Under the reducing atmosphere, the iron ore is gradually reduced to metallic iron. As the temperature rises further, the iron ore washes over the coke and flows through the pores of the porous filter layer to the lower component.

[0042] The test regime was designed with reference to the actual conditions of the blast furnace. The test regime for the tubular furnace is shown in Table 2 and... Figure 5 As shown. The specially made crucible is removed and air-cooled, then slowly cooled in the furnace or water-quenched, resulting in slag and metallic iron in the lower assembly.

[0043] Table 2 Temperature and Atmosphere Systems of Examples

[0044]

[0045] 4) After cooling, break the crucible, remove the coke from the upper component and the metallic iron from the lower component, weigh them, and calculate the weight loss rate. The weight loss rate of the coke is 38.5%.

[0046] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method of determining the reactivity of a coke iron oxide coupling reaction, characterized by, The crucible used includes an upper component and a lower component. The bottom of the upper component is provided with a porous filter layer, and the side of the lower component is provided with multiple through holes. The upper component and the lower component are connected by a concave-convex structure. The lower component has four through holes; The diameter of the through hole is 5-10 mm; The methods and steps include the following: 1) The upper and lower components are bonded together using a high-temperature adhesive; 2) Place the coke and iron ore in the upper part of the crucible in layers, with the coke in the bottom layer and the iron ore in the top layer. 3) Place the crucible containing the raw materials into the horizontal tube furnace. The through hole of the lower component of the crucible should face the direction of the incoming gas. Design the test system with reference to the actual conditions of the blast furnace. Under the reducing atmosphere, the iron ore is gradually reduced to metallic iron. As the temperature rises further, the iron ore washes over the coke and flows through the pores of the porous filter layer to the lower component. 4) The upper component contains coke, and the lower component contains liquid metal iron and liquid slag phase, which are then cooled; 5) After cooling, break the crucible, remove the coke and metallic iron, weigh them, and calculate the weight loss rate. The weight loss rate of the coke is the coke-coupled iron oxide coupling reactivity.

2. The method of determining the reactivity of a coke iron oxide coupling reaction according to claim 1, wherein, The atmosphere regime in step 3) above is as follows: Heating / cooling regime or holding temperature, heating / cooling rate or holding time atmosphere 20℃ to 200℃ 0-10℃ / min N2: 100%; 200℃ to 500℃, 10-20℃ / min, N2: 100%; 500℃ to 1200℃, 10-20℃ / min, N2: 40%-60%, CO2: 10-30%, CO: 20-40%; 1200℃ to 1500℃, 5-10℃ / min, N2: 40%-60%, CO2: 10-30%, CO: 30-50%; Hold at 1500℃ for more than 30 minutes. N2: 40%-60%, CO2: 0-30%, CO: 30-50%; 1500℃ to 20℃, 10-20℃ / min, N2: 100%; The total gas flow rate shall not be less than 2L / min.

3. The method of determining the reactivity of a coke iron oxide coupling reaction of claim 1, wherein, The diameter of the pores on the porous filter layer of the upper component is 3-4 mm.

4. The method of determining the reactivity of a coke iron oxide coupling reaction of claim 1, wherein, The mass fraction of Al2O3+SiO2 in the high-temperature adhesive is greater than 90%.

5. The method of determining the reactivity of a coke iron oxide coupling reaction of claim 1, wherein, In step 2) above, the mass ratio of coke to iron ore is 1:5-1.

6. The method of determining the reactivity of a coke iron oxide coupling reaction of claim 1, wherein, In step 2) above, the coke and iron ore undergo crushing and screening pretreatment to ensure that their particle size is between 4mm and 10mm.

7. The method of determining the reactivity of a coke iron oxide coupling reaction of claim 1, wherein, Step 4) above: Remove the crucible and air-cool or water-quench it, or let the crucible cool with the furnace.

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