Method for researching low-temperature reduction degradation property of iron ore under laboratory ore-coke coupling condition
By simulating the ore-coke coupling conditions in the laboratory, and using an alternating coke-ore loading structure and a gas reduction method, the problem of discrepancy between the research results on the low-temperature reduction pulverization of iron ore in traditional methods and actual working conditions was solved, and more accurate pulverization measurement was achieved.
Patent Information
- Application Number
- CN202511022117.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-24
- Publication Date
- 2025-11-07
AI Technical Summary
Traditional laboratory methods are insufficient to realistically simulate the complex physicochemical coupling between iron ore and coke in a blast furnace environment, leading to discrepancies between the research results on the low-temperature reduction and pulverization properties of iron ore and actual working conditions.
Using a laboratory coke-ore coupling method, the reduction pulverization index (RDI) of the ore was measured by setting up an alternating packing structure of coke bottom layer, ore middle layer and coke top layer in the reduction tube, combined with thermocouple monitoring and gas reduction, to simulate blast furnace conditions.
It improves the matching degree between laboratory research results and actual blast furnace operating conditions, reduces measurement deviation, and can more accurately reflect the low-temperature reduction and pulverization properties of iron ore.
Smart Images
Figure BDA0005514868740000021 
Figure BDA0005514868740000041 
Figure FDA0005514868730000011
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of blast furnace burden property detection, and particularly relates to a research method for low-temperature reduction pulverizability of iron ore under laboratory ore-coke coupling conditions. BACKGROUND
[0002] In the process of blast furnace ironmaking, the fragmentation and pulverization phenomenon (low-temperature reduction pulverizability, RDI) of iron ore in the low-temperature reduction zone (400-600 DEG C) due to the reduction effect of coal gas is a key problem affecting the permeability of the burden and the smooth operation of the blast furnace. In the traditional research, the characterization of the low-temperature reduction pulverizability of the iron ore is mostly based on the static test of a single ore, such as the determination of the sieve analysis index after reduction by the dynamic experiment method, or the analysis of the performance of the pellet by combining the expansion rate and the crack morphology. However, in the actual blast furnace environment, the iron ore coexists with the coke and there is a complex physical and chemical coupling effect, the traditional method is difficult to truly simulate the influence of the ore-coke synergistic reaction on the pulverization behavior, resulting in the deviation between the laboratory data and the actual working condition.
[0003] In recent years, researchers have tried to reduce RDI by optimizing additives (such as halide solution, iron component) or improving the sintering process, but these methods mostly focus on the modification of the ore itself, and do not systematically consider the dynamic influence of the coke reactivity on the pulverization process of the ore. Therefore, it is urgent to develop a pulverizability research method of ore-coke synergistic reaction under laboratory conditions, which is of great significance to reveal the pulverization mechanism in the real blast furnace environment, optimize the burden ratio and process parameters. SUMMARY
[0004] In order to solve the above technical problems, the purpose of the present application is to provide a research method for the low-temperature reduction pulverizability of iron ore under laboratory ore-coke coupling conditions, which is of great significance to reveal the pulverization mechanism in the real blast furnace environment, optimize the burden ratio and process parameters.
[0005] To solve the above technical problems, the present application adopts the following technical scheme:
[0006] The present application is a research method for the low-temperature reduction pulverizability of iron ore under laboratory ore-coke coupling conditions, comprising the following steps:
[0007] (1) Take a portion of the reduction test ore sample, and weigh the test material; take a portion of the reduction test coke sample, and weigh the test material;
[0008] (2) Pile the coke sample in step (1) on the multi-well plate of the reduction tube; fill the ore sample in step (1) in the middle of the reduction tube; cover the coke layer on the top;
[0009] (3) Insert a corrugated stainless steel mesh into the coke layer and the ore-coke mixed layer in step (2) to form an interstitial layer;
[0010] (4) Put a three-point thermocouple into the reduction tube of step (2) and seal the reduction tube; introduce N2 into the reduction tube, and then put the reduction tube into a reduction furnace, the temperature of which should not be higher than 200°C;
[0011] (5) After the insertion, the reduction furnace starts heating, the temperature increasing rate should not be higher than 10°C / min; when the temperature of the sample is 500°C, increase the N2 flow rate to 15 L / min; keep the temperature at 500°C for 30 min, so that the temperature is kept constant at 500°C±5°C; introduce reduction gas with a standard flow rate of 15 L / min±0.5 L / min to replace the inert gas, and continuously reduce for 1 h; after 1 h of reduction, stop the introduction of reduction gas, and introduce inert gas into the reduction tube with a standard flow rate of 5 L / min, and then take the reduction tube out of the furnace to cool to below 100°C, and the test is ended;
[0012] (6) Carefully take out the ore layer in the middle of the reduction tube, and measure the mass M DO , and then put it into a rotating drum to rotate at a speed of 30 r / min±1 r / min for 300 r;
[0013] (7) Take out the sample in the rotating drum of step (6) and sieve it with a sieve shaker; measure and record the mass M D1 remaining on the 3.15 mm sieve; the reduction disintegration index RDI is expressed by mass percentage and is calculated according to formula (1):
[0014]
[0015] Further, the particle size of the ore sample in step (1) is 6.3-10 mm, and 200 g of the sample is weighed with an accuracy of 0.01 g.
[0016] Further, the particle size of the coke sample in step (1) is 10-15 mm, and 100 g of the sample is weighed with an accuracy of 0.01 g.
[0017] Further, in step (2), specifically: the coke sample in (1) is taken and laid flat on the perforated plate of the reduction tube, with a thickness of 10 mm and a weight of 67 g; the ore sample in (1) is loaded in the middle of the reduction tube, with a thickness of 30 mm and a weight of 200 g; and a 5 mm thick coke layer with a weight of 33 g is covered on the top.
[0018] Further, in step (3), a corrugated stainless steel mesh with a pore size of 4 mm and an opening rate of 35% is inserted to form a 2 mm gap layer.
[0019] Further, in step (4), the standard flow rate of N2 is 5 L / min.
[0020] Further, in step (7), the sample is sieved with a sieve shaker for 60 min.
[0021] Compared with the prior art, the present application has the beneficial technical effects:
[0022] The present application realizes the simulation of blast furnace working conditions by the alternate loading structure of coke bottom layer-ore middle layer-coke top layer in the reduction pipe through the coupling pulverization test of ore and coke, and is fully compatible with the existing ISO standard test device. DETAILED DESCRIPTION
[0023] The technical solutions of the present application will be described in detail below in combination with embodiments.
[0024] The low temperature reduction pulverization test is performed on two kinds of sintered ores and two kinds of cokes in the embodiments of the present application. The chemical compositions of the sintered ores and the cokes are shown in Table 1 and Table 2.
[0025] Table 1 Chemical composition of sintered ore in the embodiments (%)
[0026] TFe FeO CaO SiO2 F S MgO P R 1# 54.73 8.98 12.18 5.42 0.12 0.047 2.01 0.062 2.59 2# 55.50 8.44 11.51 5.36 0.11 0.051 2.00 0.06 2.49
[0027] Table 2 Chemical composition and index of coke in the embodiments
[0028]
[0029] Example 1
[0030] The low temperature reduction pulverization test is performed on the 1# sintered ore shown in Table 1 and the 1# coke shown in Table 2 according to the national standard and the method of the present application respectively, and the test results are shown in Table 3. Compared with the data of the steel plant, the deviation of the traditional method is 4.5%, and the deviation of the present application is 1.4%. It can be seen that the low temperature reduction pulverization of the ore in the actual working condition can be better reflected by the present application through the coupling effect of the ore and the coke.
[0031] Table 3 1# sintered ore measured by different methods
[0032] The present invention National standard Steel plant data RDI +3.15 ]] 71.2 65.3 69.8
[0033] Example 2
[0034] The low temperature reduction pulverization test is performed on the 2# sintered ore shown in Table 1 and the 2# coke shown in Table 2 according to the national standard and the method of the present application respectively, and the test results are shown in Table 4. Compared with the data of the steel plant, the deviation of the traditional method is 4.1%, and the deviation of the present application is 2.0%. It can be seen that the low temperature reduction pulverization of the ore in the actual working condition can be better reflected by the present application through the coupling effect of the ore and the coke.
[0035] Table 4 1# sintered ore measured by different methods
[0036] The present invention National standard Steel plant data RDI +3.15 ]] 65.2 63.1 67.2
[0037] The above described embodiments are only to illustrate the preferred modes of the present application, and are not intended to limit the scope of the present application. Any modification and improvement made by those skilled in the art to the technical solutions of the present application without departing from the design spirit of the present application shall fall within the protection scope of the present application as defined by the claims.
Claims
1. A method for studying the low-temperature reduction disintegration of iron ores under laboratory coking coupling conditions, characterized in that, It comprises the following steps: (1) Take a portion of the reductive test ore sample, weigh the test material; take a portion of the reductive test coke sample, weigh the test material; (2) Lay a portion of the coke sample in step (1) on the perforated plate of the reduction tube; fill the ore sample in step (1) in the middle of the reduction tube; cover the top layer with a coke layer; (3) Insert a corrugated stainless steel mesh into the coke layer and the coke-ore mixed layer in step (2) to form a gap layer; (4) Put a three-point thermocouple into the reduction tube in step (2), seal the reduction tube; introduce N2 into the reduction tube, and then put the reduction tube into a reduction furnace, the temperature should not be higher than 200℃; (5) After being put in, the reduction furnace starts heating, the temperature rising speed should not be higher than 10℃ / min, when the temperature of the sample is 500℃, increase the N2 flow to 15L / min; keep the temperature at 500℃ for 30min, so that the temperature is constant at 500℃±5℃; introduce the reduction gas with a standard flow of 15L / min±0.5L / min to replace the inert gas, and continuously reduce for 1h; after 1h of reduction, stop introducing the reduction gas, and introduce the inert gas into the reduction tube with a standard flow of 5L / min, then take the reduction tube out of the furnace to cool to below 100℃, and the test is finished; (6) The ore layer in the middle of the reduction tube is carefully taken out and its mass M is measured DO and then put into the rotating drum to rotate at a speed of 30 r / min ± 1 r / min for 300 r; (7) The test sample in the drum of step (6) is removed and sieved using a sieve shaker; the mass M remaining on the 3.15 mm sieve is determined and recorded D1 The reduction disintegration index RDI is expressed in mass percentage and is calculated from equation (1):
2. The method for studying the low-temperature reduction disintegration properties of iron ores in the laboratory under ore-coke coupling conditions according to claim 1, characterized in that, In step (1), the particle size of the ore sample is 6.3-10mm, and 200g of test material is weighed with an accuracy of 0.01g.
3. The method for studying the low-temperature reduction disintegration properties of iron ores in the presence of laboratory cokes coupling according to claim 1, characterized in that, In step (1), the particle size of the coke sample is 10-15mm, and 100g of test material is weighed with an accuracy of 0.01g.
4. The method for studying the low temperature reduction disintegration property of iron ore under the coupling condition of laboratory ore and coke according to claim 1, characterized in that, In step (2), specifically: lay a portion of the coke sample in step (1) on the perforated plate of the reduction tube, with a thickness of 10mm and a weight of 67g; fill the ore sample in step (1) in the middle of the reduction tube, with a thickness of 30mm and a weight of 200g; cover the top layer with a coke layer with a thickness of 5mm and a weight of 33g.
5. The method for studying the low temperature reduction disintegration properties of iron ores under laboratory ore-coke coupling conditions according to claim 1, characterized in that, In step (3), insert a corrugated stainless steel mesh with a pore size of 4mm and an opening rate of 35% to form a 2mm gap layer.
6. The method for studying the low temperature reduction disintegration properties of iron ores under laboratory ore-coke coupling conditions according to claim 1, characterized in that, In step (4), the standard flow of N2 is 5L / min.
7. The method for studying the low temperature reduction disintegration properties of iron ores under laboratory ore-coke coupling conditions according to claim 1, characterized in that, In step (7), sieve for 60min with a sieve shaker.