Method for detecting melting dripping performance of iron ore

Abstract

The invention discloses a method for detecting the melting dripping performance of iron ore, which comprises the following steps: weighing a sample of 10-12.5 mm, putting into a graphite crucible, compacting by using a flattening device, and measuring the height H from the flattening device to the port of the crucible; taking out the detection sample sintered ore; weighing the sample again, putting the sample into the upper part of the sintered ore sample layer, and compacting by using a flattening device; putting the graphite crucible filled with the sample into a molten drop furnace, and loading a load of 1Kg / cm < 2 >; and supplying power to the molten drop furnace for heating according to a set heating system, and carrying out molten drop performance detection. The invention aims to provide the method for detecting the melting dripping performance of the iron ore, and the method is simple and convenient to operate and can be used for detecting the iron ore for different blast furnaces.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a method for detecting the dripping performance of molten iron ore. Background Art

[0002] The iron ore molten dripping performance test simulates the process of iron ore changing shape from solid to soft and then melting as the temperature rises and the reduction reaction proceeds during the blast furnace smelting process. It can measure the initial softening, melting, maximum pressure difference, dripping and the progress and quantity of dripping materials of iron ore. It is of great significance to determine the position and shape of the soft melting zone of iron ore in the blast furnace and the permeability of the material layer, which is of great significance for stabilizing the operation of the blast furnace.

[0003] At present, the national standard GB / T 34211-2017 - Iron Ore High-Temperature Load Reduction Soft Melting Dripping Performance Determination Method is adopted. In this determination method, since different samples (sintered ore, pelletized ore) have differences in iron grade, density, etc. under the same mass, the thickness of the material layer loaded into the graphite crucible is also different. In addition, the loading amounts of the upper and lower layers of coke are different, the thickness of the lower layer of coke is relatively large, and the iron ore enters the lower layer of coke after melting, with a long residence time. The collected data such as the softening shrinkage rate of the material layer and the corresponding temperature are biased, which affects the analysis of the molten dripping performance of the sintered ore.

[0004] Application No. 202110256597.6 A method for determining the performance of iron ore droplets by simulating blast furnace reduction conditions. By changing the reduction temperature, reduction atmosphere, reduction time, load and other parameters of the iron ore, the reduction potential conditions of the system in which the iron ore is located are more in line with the actual situation of blast furnace production. However, the determination method has a long reduction time, a large amount of reducing gas, high cost and cumbersome measurement. Summary of the invention

[0005] The purpose of the present invention is to provide a method for detecting the molten dripping performance of iron ore. The method of the present invention is simple and convenient to operate and can be used to detect iron ores for different blast furnaces.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] The present invention provides a method for detecting the molten dripping performance of iron ore, which specifically comprises the following steps:

[0008] 1) Dry the sintered ore, pelletized ore, lump ore and coke with a sample size of 10-12.5 mm in an oven at 105°C ± 5°C and place in a dryer for later use;

[0009] 2) Take a graphite crucible for testing, take out the coke in step 1), weigh 50 grams, put it into the graphite crucible, compact it with a flattener, and measure the distance H between the flattener and the end of the graphite crucible, which is called the lower coke layer;

[0010] 3) In step 1), take out the required test samples (sintered ore, pelletized ore, lump ore and coke), put them into the upper part of the coke layer of the graphite crucible in step 2), put them in batches, compact them with a flattener, measure the distance H1=H-60 between the flattener and the port of the graphite crucible, and the thickness of the sample layer is 60 mm, which is called the middle sample layer;

[0011] 4) In step 1), take out the coke, weigh 50 grams, put it into the upper part of the graphite crucible sample layer in step 3), and compact it with a flattener, which is called the upper coke layer;

[0012] 5) Place the graphite crucible loaded with the sample in step 4) into a drip furnace and load it with a load of 1 kg / cm 2 ;

[0013] 6) The melting furnace is powered on to heat up, and the heating system adopts 0-1000℃ 10℃ / min, 1000-1100℃ 2℃ / min, 1100-1650℃, 5℃ / min;

[0014] 7) When the center temperature of the dripping furnace is 0-500℃, N2 is passed at a flow rate of 3.8-4.2L / min; when >500℃, N2 is stopped and reducing gas CO+N2 is passed at a flow rate of 3.8-4.2L / min; after the sample drips, the reducing gas CO+N2 is stopped and N2 is passed at a flow rate of 3.8-4.2L / min to bring the furnace temperature below 400℃.

[0015] Furthermore, the method simulates 2000m 3 For the above blast furnaces, according to the temperature changes of iron ore at different heights in the blast furnace, the temperature rise system of the dripping furnace is set, 0-1000℃ 10℃ / min, 1000-1100℃ 2℃ / min, 1100-1650℃ 5℃ / min; the load is 1Kg / cm 2 .

[0016] Furthermore, in the step 1), the sample is dried in an oven at 105°C±5°C for 2 hours.

[0017] Furthermore, in step 1), the graphite crucible size φ 内径 75mm, height 230mm.

[0018] Furthermore, in the step 7), when the center temperature of the dripping furnace is 0-500°C, N2 is passed at a flow rate of 4L / min; when the temperature is >500°C, N2 is stopped, and reducing gas CO+N2 is passed at a flow rate of 4L / min; after the sample drips, the reducing gas CO+N2 is stopped, and N2 is passed at a flow rate of 4L / min, so that the furnace temperature is reduced to below 400°C.

[0019] Compared with the prior art, the beneficial technical effects of the present invention are:

[0020] The method of the invention is simple and convenient to operate, and can be used to detect iron ores for different blast furnaces. After the iron ore is melted, it is very easy to form drips. The obtained data has high accuracy and is closer to blast furnace production. It has a certain guiding role in blast furnace production operations and has good promotion and application value. DETAILED DESCRIPTION

[0021] Embodiment 1:

[0022] A method for detecting the melting dripping performance of iron ore, comprising the following steps

[0023] 1) Weigh 50 g of 10-12.5 mm coke, put it into a graphite crucible, compact it with a flattener, and measure the height H between the flattener and the crucible port;

[0024] 2) Take out the sintered ore sample for testing, put it into the upper part of the coke layer in step 1), put it in batches, and compact it with a flattener so that the distance between the flattener and the port of the graphite crucible is H1=H-60;

[0025] 3) Weigh 50 g of coke again, put it on the top of the sintered ore sample layer in step 2), and compact it with a flattener;

[0026] 4) Place the graphite crucible with the sample in the dripping furnace and load it with a load of 1 kg / cm 2 ;

[0027] 5) Supply power to the dripping furnace to increase the temperature according to the set heating system. The heating system adopts 0-1000℃10℃ / min, 1000-1100℃2℃ / min, 1100-1650℃, 5℃ / min; carry out molten dripping performance test, the center temperature of the dripping furnace is 0-500℃, N2 is passed, and the flow rate is 3.8-4.2L / min; >500℃, N2 is stopped, and reducing gas CO+N2 is passed, with a flow rate of 3.8-4.2L / min; after the sample drips, the reducing gas CO+N2 is stopped, and N2 is passed, with a flow rate of 3.8-4.2L / min, so that the furnace temperature will be below 400℃.

[0028] Comparison results between the method of the present invention and the national standard GB / T 34211-2017

[0029]

[0030] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for detecting the melting dripping performance of iron ore, characterized in that: The specific steps include: 1) Dry the sintered ore, pelletized ore, lump ore and coke with a sample size of 10-12.5 mm in an oven at 105°C ± 5°C and place in a dryer for later use; 2) Take a graphite crucible for testing, take out the coke in step 1), weigh 50 grams, put it into the graphite crucible, compact it with a flattener, and measure the distance H between the flattener and the end of the graphite crucible, which is called the lower coke layer; 3) In step 1), take out the required test sample, put it into the upper part of the coke layer of the graphite crucible in step 2), put it in batches, compact it with a flattener, measure the distance H1=H-60 between the flattener and the port of the graphite crucible, and the thickness of the sample layer is 60 mm, which is called the middle sample layer; 4) In step 1), take out the coke, weigh 50 grams, put it into the upper part of the graphite crucible sample layer in step 3), and compact it with a flattener, which is called the upper coke layer; 5) Place the graphite crucible loaded with the sample in step 4) into a drip furnace and load it with a load of 1 kg / cm 2 ; 6) The dripping furnace is powered on to heat up, and the heating system adopts 0-1000℃ 10℃ / min, 1000-1100℃ 2℃ / min, 1100-1650℃, 5℃ / min; 7) When the center temperature of the dripping furnace is 0-500℃, N2 is passed at a flow rate of 3.8-4.2L / min; when >500℃, N2 is stopped and reducing gas CO+N2 is passed at a flow rate of 3.8-4.2L / min; after the sample drips, the reducing gas CO+N2 is stopped and N2 is passed at a flow rate of 3.8-4.2L / min to bring the furnace temperature below 400℃.

2. The method for detecting the iron ore molten dripping performance according to claim 1, characterized in that: The method is to simulate 2000m 3 For the above blast furnaces, according to the temperature changes of iron ore at different heights in the blast furnace, the temperature rise system of the dripping furnace is set, 0-1000℃ 10℃ / min, 1000-1100℃ 2℃ / min, 1100-1650℃ 5℃ / min; the load is 1Kg / cm 2 .

3. The method for detecting the iron ore molten dripping performance according to claim 1, characterized in that: In the step 1), the sample is dried in an oven at 105°C ± 5°C for 2 hours.

4. The method for detecting the iron ore molten dripping performance according to claim 1, characterized in that: In the step 1), the graphite crucible size φ 内径 75mm, height 230mm.

5. The method for detecting the iron ore molten dripping performance according to claim 1, characterized in that: In the step 7), when the center temperature of the dripping furnace is 0-500°C, N2 is passed at a flow rate of 4L / min; when the temperature is >500°C, N2 is stopped and reducing gas CO+N2 is passed at a flow rate of 4L / min; after the sample drips, the reducing gas CO+N2 is stopped and N2 is passed at a flow rate of 4L / min to reduce the furnace temperature to below 400°C.

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