A device and method for preparing a sample for measuring the drum strength of a pellet ore

Abstract

A device and method for preparing a sample for measuring the drum strength of pellets, which are applicable to the technical field of ironmaking raw materials and pellet production inspection. The present invention realizes the rapid preparation of the sample for measuring the drum strength by prejudging the particle size during the pre-drum screening process and accurately feeding the reduction scale. The present invention provides a material outlet of the screening feeding reduction scale above the material receiving port of the drum front screen; the drum front screen is fixed on a bracket; the drum front screen is equipped with three kinds of particle size outlets: small, medium and large, and the electric unloading valve is installed on the chute of the medium particle size outlet of the drum front screen; the small particle size aggregate scale, the medium particle size aggregate reduction scale and the large particle size aggregate scale are all installed below the material outlet of the corresponding particle size of the drum front screen; the feed port of the three-way with the aggregate hopper is located below the outlet of the feeding device of the medium particle size aggregate reduction scale, which reduces the spatial size of the device for preparing the sample for measuring the drum strength of pellets and improves the speed and success rate of automatic preparation of the sample for measuring the drum strength.

Description

Technical Field

[0001] The invention belongs to the technical field of ironmaking raw materials and pellet production inspection, and in particular provides a sample preparation device for measuring the drum strength of pellets. Background Art

[0002] As the main raw material for long-process iron and steel metallurgical production, quality assurance of iron ore is a necessary condition for stable production. Carrying out quality inspection on iron ore and obtaining accurate quality indicators of iron ore in a timely manner are necessary means to grasp and control the fluctuation of iron ore quality. The drum strength of iron ore reflects the degree of crushing and pulverization of iron ore during transportation, which affects the smooth operation of blast furnace. It is an important part of iron ore quality inspection. At present, iron ore has generally adopted fully automatic sampling devices. In the past decade, the proportion of pellets in blast furnace feed has become increasingly larger, and the domestic pellet production capacity has continued to grow. The finished product belts of the newly built pellet production lines are almost all equipped with fully automatic sampling devices including automatic drum strength measurement of pellets.

[0003] The fully automatic sampling device currently used in pellet plants generally has the functions of automatic sampling, automatic particle size analysis, automatic compressive strength test, automatic drum strength determination, and automatic preparation of chemical analysis samples. It is large and slightly bulky, and the corresponding supporting buildings are about 20 meters high and cover an area of ​​about 80 square meters. If the spatial dimensions of the sample preparation device for the automatic drum strength determination of pellets can be effectively reduced, it will not only save equipment investment, but also effectively reduce the investment and floor space of supporting buildings, thereby achieving the purpose of significantly reducing the total investment in the construction of the fully automatic sampling device for pellets. The automatic drum strength determination is the most complex part of the device, and its sample preparation device is the key equipment with the largest spatial dimensions in the automatic drum strength determination. Therefore, it is very meaningful to design a relatively small sample preparation device for the drum strength determination of pellets.

[0004] At present, the preparation device for the sample of the automatic drum strength test of pellet ore used by most pellet plants is to first screen the sample into -6.3mm, 6.3~40mm, +40mm, and then collect the 6.3~40mm part into the reduction scale, and then accurately feed the reduction scale to obtain 15kg of sample on the reversible belt conveyor. If the error of the sample quality is within the range of ±1%, the sample quality is considered qualified and is sent to the drum for drum strength test through the reversible belt. Otherwise, the sample is discarded and the reduction scale is fed again, and the cycle is repeated until the sample quality error is within the range of ±1%. It is not difficult to see that the key to this device lies in the accurate control of the sample quality by the reduction scale feeding device.

[0005] If the screening feed quality is accurately controlled by the reduction scale feeding device before the sample is screened, and the sample quality measured by each aggregate weighing device set at the sample screening discharge end is used to predict the unscreened sample quality required for the sample with a mass of 15.15kg, there is a high probability that a sample with a particle size of 6.3-40mm and a mass of 15±0.15kg has been obtained in the reduction scale for collecting the sample at the same time as the screening is completed. In order to ensure the fault tolerance of the device, a tee with an aggregate hopper is specially designed to replace the reversible belt conveyor with a larger space size. When the mass of the collected 6.3-40mm sample exceeds 15.15kg, the sample quality fed to the aggregate hopper can be controlled within the qualified range through the feeding device of the reduction scale for collecting the sample. If qualified, the tee will feed the sample into the drum, otherwise the sample will be discarded. It is not difficult to see that, for the same mass of the drum sample, the sample preparation error tolerance of the device provided by the present invention is twice as large as that of the traditional device, and if the sample quality in the sample collection reduction scale is qualified during the screening process, the sample preparation time will be reduced by more than half.

[0006] 1. Terms and definitions for the determination of the automatic drum index of pellets

[0007] The following terms and definitions are taken from current standards and apply to this document.

[0008] (1) Sample: A relatively small amount of representative iron ore selected from a batch of iron ore whose quality characteristics are to be assessed.

[0009] (2) Incremental sample: A sample taken by a sampling or sample reduction device in a specific operation.

[0010] (3) Bulk sample: A sample consisting of all the additional samples that fully represents all the quality characteristics of a batch of iron ore.

[0011] (4) Subsample: A sample consisting of fewer increments than the total number of increments required for a large sample.

[0012] (5) Test specimen: A sample prepared to meet all the specified conditions of a test.

[0013] (6) Test specimen: that portion of the test specimen which is actually used in its entirety for a specific test.

[0014] (7) Sample preparation: A process for preparing a sample to be suitable for determining specified quality characteristics.

[0015] (8) Particle size: The sample fraction separated by one sieve or two sieves with different mesh sizes.

[0016] (9) Screening: The process of separating iron ore into two or more particle sizes using one or more sieves.

[0017] (10) Pelletized ore: Spherical artificial iron ore formed by forming small particles of iron ore into balls with various additives and solidifying them through heat or cold combination.

[0018] (11) Drum strength: The resistance of the pellets to particle size degradation due to impact and wear in a drum rotating for a specified time.

[0019] (12) Sample reduction: Any procedure by which the mass of any retained sample or portion is reduced without crushing it. Summary of the invention

[0020] The invention provides a device for preparing a sample for measuring the drum strength of pellets, which is applicable to the technical field of ironmaking raw materials and pellet production inspection, and solves the problems of a long time, insufficient fault tolerance and excessively large equipment space size in the existing process of preparing the sample for measuring the drum strength of pellets.

[0021] A preparation device for a sample for measuring the strength of a pelletized ore drum comprises a screening feed reduction scale 1, a drum front screen 2, a bracket 3, an electric discharge valve 4, a small-grade aggregate scale 5, a medium-grade aggregate reduction scale 6, a large-grade aggregate scale 7, and a tee with an aggregate hopper 8. The feed outlet of the screening feed reduction scale 1 is above the material receiving port of the drum front screen 2; the drum front screen 2 is fixed on the bracket 3; the drum front screen 2 is provided with three kinds of small, medium and large-grade outlets, and the electric discharge valve 4 is installed on the chute of the medium-grade outlet of the drum front screen 2; the small-grade aggregate scale 5, the medium-grade aggregate reduction scale 6 and the large-grade aggregate scale 7 are all installed below the material outlet of the corresponding grade of the drum front screen 2; the feed port of the tee with an aggregate hopper 8 is located below the outlet of the feeding device of the medium-grade aggregate reduction scale 6.

[0022] The medium particle size is the particle size required for the test sample for determining the drum strength of pellet ore, the small particle size is the particle size smaller than the lower limit of the medium particle size, and the large particle size is the particle size larger than the upper limit of the medium particle size.

[0023] The tee 8 with a collecting hopper is a tee with a collecting hopper added to the material inlet of the common tee, and the turning angle of the tee control push rod is increased.

[0024] The collecting hopper is an upper open fan-shaped column formed by welding two steel plate cross plates and two wing plates connected in a fan-shaped manner with an angle of about 90 degrees; the center of the fan-shaped circle is welded to the rotating shaft of the crank connected to the push rod, and a rotating reinforcement rib is welded on the cross plate and connected to the moving end of the crank.

[0025] The interior of the collecting hopper is lined with an inner lining, the chamfer radius of the intersecting part of the inner lining extending to the bottom of the hopper is greater than 50 mm, and the angle formed by the straight segments of the outer surface of the inner lining on the two horizontal plates is greater than 95° and less than 120°.

[0026] A method for preparing a sample for measuring the drum strength of a pellet ore, the specific steps are as follows:

[0027] Step 1: According to the requirements of the drum strength test, sufficient samples are obtained from the material to be tested, and the screening feed reduction scale 1 is in the aggregate state;

[0028] Step 2: When a batch of samples is completed and the quality of the samples in the screening feed reduction scale 1 meets the requirements, the feeding of the previous process is closed;

[0029] Step 3: Start the small-size aggregate scale 5, the medium-size aggregate reduction scale 6, and the large-size aggregate scale 7 in the aggregate state, the electric discharge valve 4 is in the open state, and the three-stage cylindrical screen 2 in front of the drum is started;

[0030] Step 4: Screening and feeding reduction scale 1 starts the screening and feeding mode to screen the sample into three particle sizes: small, medium and large;

[0031] Step 5: When the sample in the medium-sized aggregate reduction scale 6 exceeds the speed reduction mass, the screening and feeding reduction scale 1 is changed to the slow screening and feeding mode. When the sample in the medium-sized aggregate reduction scale 6 reaches the set target mass according to the proportion of all particle sizes and the weight loss prediction of the screening and feeding reduction scale 1, the screening and feeding reduction scale 1 stops feeding;

[0032] Step 6: When the sample mass in the medium-sized aggregate reduction scale 6 exceeds the critical mass, close the electric discharge valve 4. When the sample mass in the medium-sized aggregate reduction scale 6 is greater than the critical mass and less than the target mass, the drum is successfully matched. Open the three-way 8 with the aggregate hopper to the unqualified sample discarding mode. After receiving the drum aggregate mode in place, start the medium-sized aggregate reduction scale 6 fast sample delivery mode to deliver the sample to the drum.

[0033] Step 7, when the sample mass in the medium-grade aggregate reduction scale 6 is greater than the target mass, the tee 8 with the aggregate hopper is opened to the aggregate mode, and the slow sample delivery mode of the medium-grade aggregate reduction scale 6 is opened. When the reduction value exceeds the critical mass, the sample delivery of the medium-grade aggregate reduction scale 6 is stopped. At this time, if the weight loss of the medium-grade aggregate reduction scale 6 is less than the target mass, the drum is successfully matched. After receiving the drum aggregate mode in place, the qualified sample into the drum mode of the tee 8 with the aggregate hopper is opened to send the sample to the drum; if the weight loss of the medium-grade aggregate reduction scale 6 is greater than the target mass, the drum is failed. The tee 8 with the aggregate hopper is opened until the unqualified sample is discarded. If the sample in the screening feed reduction scale 1 is not enough to prepare a sample, the drum is completely failed, and the drum index is not measured in this test. If the sample is sufficient, it will be re-circulated from step 3 until the drum is successfully matched.

[0034] Step 8: If the drum preparation fails completely, start the fast screening and sample delivery mode of the screening feed reduction scale 1, the electric unloading valve 4, the small-size aggregate scale 5, the medium-size aggregate reduction scale 6, and the large-size aggregate scale 7 until all samples are screened, and at the same time start the qualified sample feeding mode of the three-way 8 with the aggregate hopper, discard all the screened samples, and re-enter step 1;

[0035] Step 9. When the drum is matched successfully, wait for the drum test data to be normal, then turn on the fast screening and sample delivery mode of the screening feeding and reducing scale 1, the electric unloading valve 4, the small-size aggregate scale 5, the medium-size aggregate reducing scale 6, and the large-size aggregate scale 7 until all samples are screened. The screening feeding and reducing scale 1 turns on the aggregate mode, and at the same time turns on the qualified sample feeding mode of the three-way 8 with the aggregate hopper, discards all the screened samples, and re-enters step 1; if the drum test needs to be repeated, and the sample prediction in the screening feeding and reducing scale 1 is not enough to prepare a sample, the drum test fails, and enters step 8; if the drum test needs to be repeated, and the sample is sufficient, it will be counted again in step 3;

[0036] Step 10. The system can be switched to manual mode. During maintenance or fault diagnosis, a one-key discard function can be set to remove the remaining materials in the entire set of equipment.

[0037] The medium particle size is the particle size required for the test sample for determining the drum strength of pellet ore, the small particle size is the particle size smaller than the lower limit of the medium particle size, and the large particle size is the particle size larger than the upper limit of the medium particle size.

[0038] The deceleration mass is a set value less than the critical mass, the critical mass is 14.85 kg, and the target mass is 15.15 kg.

[0039] In summary, the problems solved by the present invention are:

[0040] 1. Rapid preparation of samples for drum strength determination is achieved through pre-judgment of particle size during pre-drum screening and accurate feeding of reduction scale.

[0041] 2. The error tolerance of automatic preparation of drum strength test samples is doubled by accurate feeding of the pre-drum screening and the post-screening reduction scale.

[0042] 3. By adopting a specially designed tee with a collecting hopper instead of the traditional reversible belt conveyor, the spatial height of the drum test sample preparation device is reduced from about 7 meters to 4.5 meters. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1This is a schematic diagram of the sample preparation device for the pellet drum strength test in Example 1. Among them, 1. Screening feed reduction scale; 2. Screen in front of the drum; 3. Bracket; 4. Electric discharge valve; 5. Small particle size aggregate scale; 6. Medium particle size aggregate reduction scale; 7. Large particle size aggregate scale; 8. Tee with aggregate hopper.

[0044] Figure 2 , is a detailed view of the tee with a collecting hopper of component 8 of the sample preparation device for the drum strength test of pellet ore in Example 1. At this time, the tee is in the sample feeding mode. Among them, 8-1 is the tee inlet; 8-2 is the tee drum outlet; 8-3 is the tee discard outlet; 8-4 is the tee special collecting hopper; 8-5 is the collecting hopper rotating crank; 8-6 is the collecting hopper rotating push rod; 8-7 is the motor; 8-8 is the power device bracket; 8-9 is the collecting hopper rotating track hole; 8-10 is the collecting hopper rotating shaft.

[0045] Figure 3 This is a detailed view of the tee with a collection hopper in part 8 of the sample preparation device for the pellet drum strength test in Example 1. At this time, the tee is in the unqualified sample discarding mode. The dimension C is the width of the tee inlet, L is the height of the tee inlet section, L1 is the length of the tee drum outlet section, C1 is the width of the tee drum outlet, L2 is the length of the tee discard outlet section, and C2 is the width of the tee discard outlet. The angle α is the rotation angle range of the 8-6 collection hopper rotating push rod pushing the 8-5 collection hopper rotating crank, which is greater than the rotation angle of the ordinary tee push rod pushing the rotating crank.

[0046] Figure 4 This is a detailed view of the tee with a collection hopper in component 8 of the sample preparation device for measuring the drum strength of pellets in Example 1. At this time, the tee is in the collection mode.

[0047] Figure 5 It is the A-direction view of 4, where 8-1 is the three-way inlet; 8-2 is the three-way drum outlet; 8-4 is the three-way special collecting hopper; 8-5 is the collecting hopper rotating crank; 8-6 is the collecting hopper rotating push rod; 8-7 is the motor; 8-8 is the power device bracket; 8-9 is the collecting hopper rotating track hole; 8-10 is the collecting hopper rotating shaft. The dimension B is the length of the three-way inlet, and B1 is the length of the three-way drum outlet.

[0048] Figure 6 Detailed top view of the special collecting hopper with a three-way hopper of the pellet drum strength test sample preparation device of Example 1. 8-4-1 is the rotating reinforcement rib, 8-4-2 is the rotating shaft, and 8-4-3 is the hopper wing plate. The wing plate 8-4-3 is made of Q235 steel plate, and the rotating shaft 8-4-2 and the rotating reinforcement rib 8-4-1 are made of high-carbon bearing steel. B2 is the outer length of the collecting hopper, which is greater than Figure 5 The B value.

[0049] Figure 7 This is a detailed diagram of the special collecting hopper with a tee of the collecting hopper of the component 8 of the sample preparation device for the strength determination of the pellet drum in Example 1. Among them, 8-4-1 is a rotating reinforcement rib, 8-4-2 is a rotating shaft, 8-4-3 is a hopper wing plate, 8-4-4 is a hopper cross plate, and 8-4-5 is a wear-resistant lining. Among them, the hopper cross plate 8-4-4 and the wing plate 8-4-3 are made of Q235 steel plate, the rotating shaft 8-4-2 and the rotating reinforcement rib 8-4-1 are made of high-carbon bearing steel, and the wear-resistant lining 8-4-5 is made of wear-resistant manganese steel. β is the angle of the straight section of the wear-resistant lining. DETAILED DESCRIPTION

[0050] Embodiment 1:

[0051] like Figure 1 As shown, the present invention comprises: a screening feed reduction scale 1; a drum front screen 2; a bracket 3; an electric discharge valve 4; a -6.3mm particle size aggregate scale 5; a 6.3-40mm particle size aggregate reduction scale 6; a +40mm particle size aggregate scale 7; and a tee with an aggregate hopper 8. Among them, the feeding outlet of the screening feed reduction scale 1 is above the material receiving port of the drum front screen 2; the drum front screen 2 is fixed on the bracket 3; the electric discharge valve 4 is installed on the chute of the 6.3-40mm particle size outlet of the screening material; the -6.3mm particle size aggregate scale 5 and the 6.3-40mm particle size aggregate reduction scale 6 and the +40mm particle size aggregate scale 7 are all installed below the material outlet of the corresponding particle size of the drum front screen 2; the feed port of the tee with an aggregate hopper 8 is located below the outlet of the feeding device of the 6.3-40mm particle size aggregate reduction scale 6. Among them, the screening feeding reduction scale 1 adopts a 100kg reduction scale with adjustable feeding speed, the drum pre-screen 2 adopts a three-stage cylindrical screening machine, the -6.3mm particle size aggregate scale 5 adopts a 10kg hopper scale, the 6.3-40mm particle size aggregate reduction scale 6 adopts a 20kg reduction scale, and the +40mm particle size aggregate scale 7 adopts a 10kg hopper scale.

[0052] like Figure 3 As shown, the parameters of the tee with a collecting hopper are: C = C1 = C2 = 300 mm, L = 400 mm, L1 = L2 = 500 mm. The maximum rotation angle of the crank is α = 150°.

[0053] like Figure 5 As shown, B=400mm, B1=550mm.

[0054] like Figure 6 As shown, B2=500mm.

[0055] like Figure 7 As shown, the straight section angle of the inner lining of the special aggregate hopper is β=105°.

[0056] The process flow of preparing the drum test sample by mixing the qualified drum sub-sample is as follows:

[0057] 1. According to the requirements of drum strength test, obtain enough samples from the material to be tested, and the screening feed reduction scale 1 is in the aggregate state;

[0058] 2. When a batch of samples is completed and the quality of the samples in the screening feed reduction scale 1 meets the requirements, the feeding of the previous process is closed;

[0059] 3. Start -6.3mm aggregate scale 5, 6.3~40mm aggregate reduction scale 6, +40mm aggregate scale 7 in aggregate state, the electric discharge valve 4 discharge valve is in the open state, start the drum front screen 2 three-stage cylindrical screen;

[0060] 4. Screening and feeding reduction scale 1 starts the screening and feeding mode, and screens the sample into three particle sizes: -6.3mm, 6.3-40mm, and +40mm;

[0061] 5. When the sample (6.3-40mm) in the 6.3-40mm aggregate reduction scale 6 exceeds 10Kg, the screening and feeding reduction scale 1 equipment changes to the slow screening and feeding mode. When the sample in the 6.3-40mm aggregate reduction scale 6 reaches 15.15kg according to the proportion of all particle sizes and the weight loss prediction of the screening and feeding reduction scale 1, the screening and feeding reduction scale 1 stops feeding;

[0062] 6. When the mass of the sample in the 6.3-40mm particle size aggregate reduction scale 6 exceeds 14.85kg, close the electric discharge valve 4; when the mass of the sample in the 6.3-40mm particle size aggregate reduction scale 6 is greater than 14.85kg and less than 15.15kg, the drum is successfully matched, and the three-way 8 with the aggregate hopper is opened to the unqualified sample discarding mode. When the drum aggregate mode is received in place, start the 6.3-40mm particle size aggregate reduction scale 6 fast sample delivery mode to deliver the sample to the drum.

[0063] 7. When the sample mass in the 6.3-40mm particle size aggregate reduction scale 6 is greater than 15.15kg, open the tee 8 with aggregate hopper to the aggregate mode, and open the slow sample delivery mode of the 6.3-40mm particle size aggregate reduction scale 6. When the reduction value exceeds 14.85kg, stop the 6.3-40mm particle size aggregate reduction scale 6 from delivering samples. At this time, if the weight loss of the 6.3-40mm particle size aggregate reduction scale 6 is less than 15.15kg, the drum is successfully matched. After receiving the drum aggregate mode in place, open the qualified sample into the drum mode of the tee 8 with aggregate hopper to deliver the sample to the drum. If the weight loss of 6.3-40mm aggregate reduction scale 6 is greater than 15.15kg, the drum preparation fails. Open the tee 8 with the aggregate hopper until the unqualified sample is discarded. If the sample in the screening feed reduction scale 1 is not enough to prepare a sample, the drum preparation fails completely. The drum index is not measured in this test. If the sample is sufficient, recycle from step 3 until the drum preparation is successful.

[0064] 8. If the drum preparation fails completely, turn on the fast screening and sample delivery mode of the screening feed reduction scale 1, electric unloading valve 4, small-size aggregate scale 5, medium-size aggregate reduction scale 6, and large-size aggregate scale 7 until all samples are screened, and at the same time turn on the qualified sample feeding mode of the three-way 8 with the aggregate hopper, and discard all the screened samples. Re-enter the first step.

[0065] 9. When the drum is matched successfully, wait for the drum test data to be normal, then turn on the fast screening and sample delivery mode of the screening feeding and reducing scale 1, the electric unloading valve 4, the small-size aggregate scale 5, the medium-size aggregate reducing scale 6, and the large-size aggregate scale 7 until all samples are screened. The screening feeding and reducing scale 1 turns on the aggregate mode, and at the same time turns on the qualified sample feeding mode of the three-way 8 with the aggregate hopper, and all the screened samples are discarded. Re-enter the first step. If the drum test needs to be repeated, and the sample prediction in the screening feeding and reducing scale 1 is not enough to prepare a sample, the drum test fails and enters step eight; if the drum test needs to be repeated and the sample is sufficient, it will be counted back into step 3.

[0066] 10. The system can be switched to manual mode. Figure 2 During maintenance or fault diagnosis, a one-key discard function can be set to remove the remaining materials in the whole set of equipment.

Claims

1. A device for preparing a sample for measuring the drum strength of a pellet ore, characterized in that: The device comprises a screening feed reduction scale (1), a drum front screen (2), a bracket (3), an electric discharge valve (4), a small-grade aggregate scale (5), a medium-grade aggregate reduction scale (6), a large-grade aggregate scale (7), and a tee with an aggregate hopper (8); the feed outlet of the screening feed reduction scale (1) is above the material receiving port of the drum front screen (2); the drum front screen (2) is fixed on the bracket (3); the drum front screen (2) is provided with three kinds of small, medium and large-grade outlets, and the electric discharge valve (4) is installed on the chute of the medium-grade outlet of the drum front screen (2); the small-grade aggregate scale (5), the medium-grade aggregate reduction scale (6) and the large-grade aggregate scale (7) are all installed below the material outlets of the drum front screen (2) of the corresponding grade; the feed inlet of the tee with an aggregate hopper is located below the outlet of the feeding device of the medium-grade aggregate reduction scale (6); The tee with a material collecting hopper (8) is a tee with a material collecting hopper added to the material inlet of the common tee, and the turning angle of the tee control push rod is increased.

2. The device for preparing a sample for measuring the drum strength of pellets according to claim 1, characterized in that: The medium particle size is the particle size required for the test sample for determining the drum strength of pellet ore, the small particle size is the particle size smaller than the lower limit of the medium particle size, and the large particle size is the particle size larger than the upper limit of the medium particle size.

3. The device for preparing a sample for measuring the drum strength of pellets according to claim 1, characterized in that: The collecting hopper is an upper open fan-shaped column formed by welding two steel plate cross plates and two wing plates connected in a fan-shaped manner with an angle of about 90 degrees; the center of the fan-shaped circle is welded to the rotating shaft of the crank connected to the push rod, and a rotating reinforcement rib is welded on the cross plate and connected to the moving end of the crank.

4. The device for preparing a sample for measuring the drum strength of pellets according to claim 3, characterized in that: The interior of the collecting hopper is lined with an inner lining, the chamfer radius of the intersecting part of the inner lining extending to the bottom of the hopper is greater than 50 mm, and the angle formed by the straight segments of the outer surface of the inner lining on the two horizontal plates is greater than 95° and less than 120°.

5. A method for preparing a sample for measuring the drum strength of a pellet ore, characterized in that: Step 1: According to the requirements of the drum strength test, sufficient samples are obtained from the material to be tested, and the sieving feed reduction scale (1) is in the aggregate state; Step 2: When a batch of samples is completed and the sample quality in the screening feed reduction scale (1) meets the requirements, the feed of the previous process is closed; Step 3: Start the small-size aggregate scale (5), the medium-size aggregate reduction scale (6), and the large-size aggregate scale (7) to put them in the aggregate state, the electric discharge valve (4) is in the open state, and the three-stage cylindrical screen in front of the drum (2) is started; Step 4: Screening and feeding reduction scale (1) Turn on the screening and feeding mode to screen the sample into three particle sizes: small, medium and large; Step 5: When the sample in the medium-sized aggregate reduction scale (6) exceeds the deceleration mass, the screening and feeding reduction scale (1) is changed to a slow screening and feeding mode. When the sample in the medium-sized aggregate reduction scale (6) reaches the set target mass according to the proportion of all particle sizes and the weight loss prediction of the screening and feeding reduction scale (1), the screening and feeding reduction scale (1) stops feeding; Step 6: When the sample mass in the medium-sized aggregate reduction scale (6) exceeds the critical mass, the electric discharge valve (4) is closed. When the sample mass in the medium-sized aggregate reduction scale (6) is greater than the critical mass and less than the target mass, the drum is successfully matched. The three-way (8) with the aggregate hopper is opened to the unqualified sample discarding mode. When the drum aggregate mode is received, the medium-sized aggregate reduction scale (6) is started to deliver the sample to the drum in the fast sample delivery mode. Step 7, when the sample mass in the medium-grade aggregate reduction scale (6) is greater than the target mass, the tee (8) with the aggregate hopper is opened to the aggregate mode, and the slow sample delivery mode of the medium-grade aggregate reduction scale (6) is opened. When the reduction value exceeds the critical mass, the sample delivery of the medium-grade aggregate reduction scale (6) is stopped. At this time, if the weight loss of the medium-grade aggregate reduction scale (6) is less than the target mass, the drum preparation is successful. After receiving the drum aggregate mode in place, the tee (8) with the aggregate hopper is opened to the qualified sample drum mode to deliver the sample to the drum; if the weight loss of the medium-grade aggregate reduction scale (6) is greater than the target mass, the drum preparation fails. The tee (8) with the aggregate hopper is opened until the unqualified sample is discarded. If the sample in the screening feed reduction scale (1) is not enough to prepare a sample, the drum preparation fails completely, and the drum index is not measured in this test. If the sample is sufficient, the cycle starts from step 3 again until the drum preparation is successful. Step 8: If the drum preparation fails completely, the screening feed reduction scale (1), electric discharge valve (4), small-size aggregate scale (5), medium-size aggregate reduction scale (6), and large-size aggregate scale (7) are turned on in the rapid screening and sample delivery mode until all samples are screened, and at the same time, the qualified sample feeding mode of the three-way with aggregate hopper (8) is turned on, all the screened samples are discarded, and the process of re-entering step 1 is resumed; Step 9: When the drum is matched successfully, wait for the drum test data to be normal, then turn on the fast screening and sample delivery mode of the screening feed reduction scale (1), the electric discharge valve (4), the small particle aggregate scale (5), the medium particle aggregate reduction scale (6), and the large particle aggregate scale (7), until all samples are screened, the screening feed reduction scale (1) turns on the aggregate mode, and at the same time turns on the qualified sample drum mode of the three-way (8) with the aggregate hopper, all the screened samples are discarded, and the step one is re-entered; if the drum test needs to be repeated, and the sample in the screening feed reduction scale (1) is not enough to prepare a sample, the drum test fails, and the step eight is entered; if the drum test needs to be repeated, and the sample is sufficient, it is counted again into step three; Step 10. The system can be switched to manual mode. During maintenance or fault diagnosis, a one-key discard function can be set to remove the remaining materials in the entire set of equipment.

6. The method for preparing a sample for measuring the drum strength of pellets according to claim 5, characterized in that: The medium particle size is the particle size required for the test sample for determining the drum strength of pellet ore, the small particle size is the particle size smaller than the lower limit of the medium particle size, and the large particle size is the particle size larger than the upper limit of the medium particle size.

7. The method for preparing a sample for measuring the drum strength of pellets according to claim 5, characterized in that: The deceleration mass is a set value less than the critical mass, the critical mass is 14.85 kg, and the target mass is 15.15 kg.

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