CN111238971B - Method for evaluating falling strength of green pellets - Google Patents
Method for evaluating falling strength of green pellets Download PDFInfo
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- G01—MEASURING; TESTING
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- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/32—Investigating strength properties of solid materials by application of mechanical stress by applying repeated or pulsating forces
- G01N3/34—Investigating strength properties of solid materials by application of mechanical stress by applying repeated or pulsating forces generated by mechanical means, e.g. hammer blows
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/003—Generation of the force
- G01N2203/0032—Generation of the force using mechanical means
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/0058—Kind of property studied
- G01N2203/006—Crack, flaws, fracture or rupture
- G01N2203/0062—Crack or flaws
- G01N2203/0064—Initiation of crack
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- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
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- G01N2203/0067—Fracture or rupture
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- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N2203/02—Details not specific for a particular testing method
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- G01N2203/0218—Calculations based on experimental data
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2203/00—Investigating strength properties of solid materials by application of mechanical stress
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Abstract
The invention discloses a method for evaluating the falling strength of green pellets, which adopts random sampling or systematic samplingSampling the green pellets of the batch to be inspected, extracting at least 50 green pellets, and sealing the green pellets in a sample belt for later use; vertically fixing the scale on the ground, marking at a position of 0.5-2 m, and paving a bottom plate on the ground to finish the preparation of the testing device; dropping the green pellets for test from the mark, and measuring the dropping strength Q of the green pellets for test LX‑i (ii) a Calculating the falling strength Q of the green pellets LX And average drop strength
Calculating the dispersion V of the falling strength of the green pellets LX (ii) a According to the dispersion V LX Determining the obtained Q LX Determining whether to continue the test until a qualified Q is obtained LX Is or all test samples are tested to completion. The method can accurately and objectively evaluate the falling strength of the green pellets.
Description
Technical Field
The invention belongs to the technical field of steel and nonferrous metallurgy, and particularly relates to a method for evaluating the falling strength of green pellets.
Background
In the iron-making process, green pellets are the raw material for manufacturing metal pellets and are an important component of the raw material entering a furnace. In some non-ferrous metal smelting processes, green pellets produced using drums/discs can be fed directly into the furnace. However, in some factories, return ores or auxiliary materials are processed by a ball press machine to produce granules to be matched with the furnace. In the manufacturing process, the physical properties of green pellets are greatly different due to the difference of moisture, components, rotation parameters or pressure parameters (ball press).
The traditional method for evaluating the falling strength of the green pellets is mainly characterized in that the number of times of cracks of the green pellets is counted, and the average number of times of cracks is considered as an index of the falling strength. The method is simple and quick, is suitable for being used by a pelletizer on site, but has insufficient accuracy and objectivity, and cannot be applied to all kinds of green pellets. For example:
1) The pellets manufactured by the press and the pellets manufactured by the disc are different in physical properties, and the original falling height, falling frequency and impact target may not be suitable for use; the test method should be distinguished from conventional green pellets.
2) 2 samples, 1 green pellet was completely broken and the other 1 had only cracks, but the number of features was the same. If the conventional evaluation method is used, their falling strengths are the same, but they are actually different. The latter should have a greater drop strength than the former in practice, and may be more effective for production than the first.
3) One green pellet broke completely at time 5 and another broke at time 6 (no cracking or chipping occurred with previous drop). The latter is larger than the former if evaluated by conventional methods. In practice it is possible that the drop strength of both will be the same, even if the former is greater than the latter.
4) How can the data on the falling strength of the same batch of raw material be determined if the dispersion is particularly large? The result obtained by averaging is also difficult to have confidence. How to judge the overall production quality of the batch?
Therefore, it is necessary to design an accurate, objective and wide-range evaluation method for different kinds of green pellets. The new method considers the factors of the strength embodiment of a single sample, the quality of the whole batch, the influence of the test process on the result and the like, is convenient to use and easy to implement, and can be implemented even without an auxiliary tool.
Disclosure of Invention
The invention aims to solve the technical problem of providing a green pellet falling strength evaluation method which is accurate, objective and wider in applicability and aims at overcoming the defects in the prior art.
The invention adopts the following technical scheme:
a green pellet falling strength evaluation method comprises the following steps:
s1, sampling the green pellets of a batch to be inspected by adopting a random sampling or system sampling mode, extracting at least 50 green pellets and sealing the green pellets in a sample belt for later use;
s2, vertically fixing the scale on the ground, marking at a position of 0.5-2 m, and paving a bottom plate on the ground to finish the preparation of the testing device;
s3, dropping the green pellets for testing from the marked position in the step S2, and measuring the dropping strength Q of the green pellets for testing LX-i ；
S4, calculating the falling strength Q of the green pellets LX And average drop strength Q LX ；
S5, calculating the dispersion V of the falling strength of the green pellets LX ；
S6, according to the dispersion V LX Determining Q obtained in step S2 LX Determining whether the test is continued to obtain qualified Q LX Or until all test samples have been tested.
Specifically, in step S1, the extracted green pellets are detected within 4 hours.
Specifically, in the step S2, the bottom plate is made of a quenched carbon steel plate with a thickness greater than 1cm, or made of a ceramic plate with the same hardness.
Specifically, step S3 specifically includes:
s301, the green pellets to be tested fall from the marked positions on the scale and impact on the bottom plate.
S302, checking the crushing state, if the crushing state does not exist, repeating the step S301 until cracks appear or the crushing is finished, and recording the times m of the generation of the crushing and the cracks L-i 。
S303, if the green pellets are broken, recording the number j of fragments i ；
S304, if the green pellets are not broken and only cracks are generated, recording the crack size index 1/y i ；
S305, when the number of the test samples is 10, calculating to obtain the falling strength Q of the green pellets LX-i 。
Further, in step S303, j is used for the green pellets to be completely cracked, the counting range is that fragments with the mass of the primary pellets is more than 20%, and if only cracks are generated and the primary pellets are not completely cracked, j =1; if no fragments with a mass >20% of the mass of the primary pellets can be found, the maximum value of j is 5.
Further, in step S304, when the crack coverage area exceeds 1/2 of the pellet surface area, y =3; when the crack coverage area is 1/4-1/2 of the pellet surface area, y =2; when the crack coverage area is 0 to 1/4 of the pellet surface area, y =1.
Further, in step S305, the drop strength Q LX-i The following were used:
wherein m is L-i The number of falls in the case of generation of cracks; j is the number of fragments; 1/y is the crack size index.
Specifically, in step S4, Q is determined for each green pellet LX-i Calculating the number N of the green pellets to obtain Q LX The following were used:
wherein N is the total number of samples to be tested, and N is not less than 10; i ≦ N.
Specifically, in step S5, the dispersion V of the drop strength of the green pellets of the batch is inspected LX The following were used:
wherein N is the total number of samples to be tested, and N is not less than 10; i ≦ N.
Specifically, step S6 specifically includes:
s601, firstly testing 10 samples, and obtaining a sample value Q LX Dispersion V of LX Stopping the test when the value is less than or equal to 0.2, and enabling the tested data to be qualified;
s602, when V LX If the sample does not meet the requirement, continuously testing 10 samples, and obtaining the overall dispersion V of the sample LX Stopping testing when the value is less than or equal to 0.2 and + x, and enabling the tested data to be qualified;
s603, analogizing to determine the value V LX Increasing x each time until 50 samples are tested;
s604, when Q LX When the dispersion finally does not meet the judgment requirement and continuously increases, the inspection batch is judged to not meet the use requirement.
Compared with the prior art, the invention has at least the following beneficial effects:
the invention relates to a green pellet falling strength evaluation method, which adopts variable falling height, comprehensively considers the influence of the sample fracture degree (crack size and fragment number) and the falling frequency on the final result, and objectively and accurately evaluates the falling strength of various green pellets. Meanwhile, the method is used for evaluating the production quality of the green pellets on the basis of the statistical principle and the step-by-step test results, can be applied to production field and laboratory research, and has reference value for measuring the falling strength of other fragile samples.
Furthermore, the samples were taken within 4 hours of testing, taking into account the change in moisture and internal structure of the green pellets over time. The moisture and structural changes of the green pellets cause slow pulverization and usually lose most of their strength within 1 week. To obtain sufficiently accurate results, testing is required immediately after the sample is taken. For a manufacturing enterprise, hourly routine testing is performed immediately after procurement. The change of the moisture of the green pellets can be relieved by adopting the sample bag for packaging, but the waiting time is not too long. It was found through long-term practice that the physical properties of the samples changed slightly within 2 h. The continuous change in moisture (north) for 4 hours gives a large deviation in the test results.
Further, the carbon steel plate of which the thickness is 1cm or more and the hardness is not less than 55HRC is set as the collision floor, with reference to the conventional method, and the hardness is specified in detail. The conventional method is to use a steel plate of 1cm, but the hardness of the steel plate is not specified. Therefore, the impact bottom plate with the thickness of more than 1cm is adopted, the impact force needs to be completely fed back to the pellet, and if the thickness is insufficient, the same effect is difficult to achieve. The thickness over 1cm has high safety coefficient, and can be suitable for different pellet impacts. The impact bottom plate with the hardness being not less than 55HRC is adopted, because the impact on the test result is different by adopting the bottom plates with different hardness; the requirement of the hardness of not less than 55HRC is slightly higher than that of steel materials used in conventional mechanical manufacturing, but lower than that of high-quality cutting tools and high-strength structural steel, and the limit requirement of impact is met. The steel plate is made of quenched carbon steel, so that the steel plate is hard enough, the possibility of generating cracks due to ball collision is higher, and the test is convenient to carry out; secondly, the materials are easy to obtain, if stainless steel plates are adopted, the price is higher, and the ceramic plates are easy to obtain but have different materials from steel production machines, so that the ceramic plates can be used as standby.
Further, step S3 obtains the test value Q preliminarily LX The preliminary value is based on the average of 10 sample tests. The benefit of setting S3 is: first, in the case of a stable overall quality of the raw material, accurate results are obtained with a small number of measurements (based on V) LX Determination of (1). Second, reduce Q LX Possible error of value (if Q) LX The value can not be judged, and two possibilities exist, namely, the value is caused by test errors, and the quality of the raw material is unstable; increase the measurement times without determination, reduce the test error and objectively show the overall quality of the raw material).
Further, step S4 illustrates Q LX Detailed calculation process of the value. Q LX The calculation of the values adds to the description of the degree of sample disruption relative to conventional methods. The degree of fracture is mainly reflected in the number of fragments and cracks that meet the requirements. Q of conventional method LX The value is the number of times when cracks or fractures occur, but the degree of fracture is in fact directly related to the strength of the sample and cannot be ignored. The formula is set on the basis that the larger the number of chips and the number of cracks, the lower the drop strength. The results thus obtained are more accurate than in the conventional methods.
Further, step S5 results in Q LX Criterion of value V LX . To obtain V LX Has the advantage that Q can be determined LX Whether the value meets the accuracy requirement. V LX Is substantially Q LX The dispersion of values, or the ratio of variance to mean, is a dimensionless parameter. V LX Greater surface Q LX The larger the distribution interval of the values, the worse the overall quality of the raw material.
Further, step S6 illustrates how to use the criterion V LX And Q LX And (5) subsequent processing of the value. Setting a judgment basis V LX To scientifically determine Q LX Whether the value is reasonable or not, and simultaneously, the testing workload is reduced. When the determination is passed, V LX The mission is over and the test is terminated. When the judgment is failed, V is set LX The added value x is mainly used for expanding the judgment value interval and increasing the probability that the secondary test result passes the judgment. If the determination fails, either the dispersion of the raw material is actually high or the error is high. Increasing the number of tests can correct part of the errors and verify the dispersion of the raw materials. Increase of V LX The value is to increase the tolerance to errors and dispersion, avoiding Q LX The value still fails to verify when relaxed further.
In conclusion, the method can accurately and objectively evaluate the falling strength of the green pellets.
The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.
Drawings
FIG. 1 is a schematic view of a testing apparatus;
FIG. 2 is a schematic view of drop strength;
fig. 3 is a diagram of the dispersion.
Detailed Description
In black and colored metallurgical processes, green pellets manufactured by a disc or roller ball making machine are evaluated for the drop strength by using the green pellet drop strength evaluation method, the drop height is usually 0.5 m, but can be adjusted within the range of 0.5-2 m according to actual requirements. The dropping point is provided with a steel plate or a ceramic plate with the thickness of not less than 1cm and the hardness of not less than 55HRC as an impact surface. The dropping process may be accomplished using automated dropping equipment or manually.
Referring to fig. 1, the method for evaluating the falling strength of green pellets according to the present invention comprises the following steps:
s1, sampling products of a checking batch;
extracting a test object, namely the green pellets in the same batch, and extracting more than 50 samples at minimum in a random sampling or system sampling mode; the extracted sample was sealed in a sample tape and the detection was performed within 4 h.
S2, preparing a testing device;
by using a complete set of experimental equipment on the market, a long ruler can be selected and vertically fixed on the ground, a mark is made at the position of 0.5 m, and then a bottom plate is laid on the ground. The bottom plate is a quenched carbon steel plate with the thickness of more than 1cm and the hardness of not less than 55 HRC; or a ceramic sheet of the same hardness is used instead.
S3, falling strength Q of sample LX Measuring;
s301, the tested sample falls from the marked position on the scale and impacts on a bottom plate with the thickness of more than 1 cm.
S302, checking the crushing state, if the crushing state does not exist, repeating the step S301 until cracks appear or the crushing is finished, and recording the times m of the generation of the crushing and the cracks L-i 。
S303, if the green pellets are broken, recording the number j of fragments i ；
j is mainly used when the green pellets are completely cracked, the counting range is that the mass of the green pellets is more than 20 percent, if only cracks are generated and the green pellets are not completely cracked, j =1; if no chips with mass >20% of the mass of the primary pellets can be found, the maximum value of j is 5; the determination of the j value is assisted by a one-thousandth balance (a one-hundredth balance or a kilogram balance can be adopted for raw materials with larger mass of a single sample).
S304, if the green pellets are not broken and only cracks are generated, recording the crack size index 1/y i ；
When the crack coverage area exceeds 1/2 of the pellet surface area (including the state of chip splitting), y =3; when the covering area of the cracks is 1/4-1/2 of the surface area of the pellets, y =2; when the crack coverage area is 0 to 1/4 of the pellet surface area, y =1.
S305, when the test sample is full of 10, comparing y i 、j i 、m L-i Substituting the formula (1) to obtain the falling strength Q of the sample LX-i The following were used:
wherein m is L-i The number of falls in the case of generation of cracks; j is the number of fragments; 1/y is a crack size index;
s4, falling strength Q of product LX And average drop strength
Calculating (1);
q of each sample LX-i Substituting the number N of the samples into a formula (2), and calculating to obtain Q LX And
the following:
wherein, the first and the second end of the pipe are connected with each other,
is Q LX N is the total number of samples to be tested, and N is not less than 10; i ≦ N.
S5, dispersion V of falling strength of product LX Calculating (1);
substitution into Q LX-i 、
The number N of the samples is expressed in a formula (3) to obtain the dispersion V of the falling strength of the batch of products LX The following:
the large drop strength indicates that the green pellets are not easy to crack or break, and the small dispersion indicates that the quality of the same batch of products is relatively uniform.
And S6, judging data.
Judgment V LX If the content of the V is less than 0.2, terminating the test if the content of the V is less than 0.2, continuing to test 10 samples if the content of the V is not less than 10, repeating the steps S1 to S5, and then carrying out V again LX Until a full 50 samples are tested.
The actual test sample quantity is determined as follows:
s601, firstly testing 10 samples, wherein the sample value Q LX Dispersion V of LX When the temperature is less than or equal to 0.2, the test is stopped, and the test data is qualified.
S602, e.g. V LX If the sample does not meet the requirements, continuously testing 10 samples, and obtaining the overall dispersion V of the samples LX Stopping testing when the value is less than or equal to 0.2 and + x, and enabling the tested data to be qualified;
s603, analogizing to the above, judging the value V LX Increasing x each time until 50 samples are tested;
s604, e.g. Q LX The dispersion degree of (A) does not meet the judgment requirement finally, and the dispersion degree tends to increase continuously, which indicates that the quality of the batch of samples is extremely unstable and does not meet the use requirement.
Note: v LX The magnitude of each increase is not unique and can be adjusted according to the stringency requirements on the data and the possible slack of the data, x = 0.01-0.05.
The raw pellets in the method are not limited to iron-making raw materials, but can also be raw materials for lead smelting, lead pyrometallurgy, copper smelting and the like. They are generally characterized by low physical strength, brittle upon impact, and even time-dependent changes.
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without inventive step based on the embodiments of the present invention, are within the scope of protection of the present invention.
Examples
A certain lead smelting plant adopts a ball press process to produce various green pellets, wherein the green pellets are spherical and have the diameter of 15mm. It is necessary to know the drop strength of these pellets, as well as the production quality uniformity of the pellets. There were 7 samples, each under 3t, the species being classified by water content: 0%, 1%, 2%, 3%, 4%, 6%, 8%. Meanwhile, a traditional method and the new method are adopted for testing, and evaluation results of the traditional method and the new method are compared.
The traditional method is to drop the steel plate at a height of 2m and impact the steel plate with a thickness of 1 cm. The number of drops when a fracture or crack occurred was counted.
The results of the tests and calculations using the conventional and novel methods are shown in tables 1 and 2. For convenient comparison, Q is added LX And V LX A comparison of the figures was made as shown in figures 2 and 3.
TABLE 1 measurement of the drop Strength of lead-containing green pellets by conventional method
TABLE 2 measurement of the drop Strength of lead-containing green pellets by a novel method
It can be seen that Q is obtained by 2 methods LX The trend of (c) is the same. When the difference is that the water content is 3% and 4%, the water content is 4% higher by adopting the traditional method, and the water content is the same by adopting the new method. The new method considers the cracking degree and the crushing time of the green pellets to obtain more objective Q LX The value is obtained. Dispersion V LX All tend to be smaller with water content, V LX-2 Maximum at 2% moisture content. The results of fig. 3 differ using the conventional and new methods. The traditional method shows that the lead-containing granules are unstable in quality in the range of 0-4% of water content, while the new method shows that the lead-containing granules are unstable in quality in the range of 2-6%. This is because the new method takes into account the extent of sample breakage.
V LX The initial value was taken to be 0.2 and x was taken to be 0.05. The final value was 0.4. The novel process shows that V is only present when the water content is greater than 6% LX Less than 0.4. The lead-containing granules are proved to have unstable quality in a range of 2 to 6 percent of water content, have stable quality in a range of 0 to 2 percent of water content and have Q LX And too low to fit into the furnace. In the region of water content greater than 6%, drop strength Q LX-i High value, but degree of dispersion V LX And the production quality is relatively stable due to the fact that the content of the product is very low.
The above contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention should not be limited thereby, and any modification made on the basis of the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.
Claims (3)
1. The method for evaluating the falling strength of the green pellets is characterized by comprising the following steps of:
s1, sampling the green pellets of a batch to be inspected by adopting a random sampling or system sampling mode, extracting at least 50 green pellets and sealing the green pellets in a sample belt for later use;
s2, vertically fixing the scale on the ground, marking at a position of 0.5-2 m, and paving a bottom plate on the ground to finish the preparation of the testing device;
s3, dropping the test green pellets from the marked position in the step S2, and measuring the dropping strength Q of the ith test green pellets LX-i The method specifically comprises the following steps:
s301, dropping the green pellets to be tested from the marked positions on the scale and impacting the green pellets on a bottom plate;
s302, checking the crushing state, if the crushing state does not exist, repeating the step S301 until cracks or crushing occurs, and recording the ithTest of the number m of fractures and cracks of the green pellets L-i ；
S303, if the green pellets are broken, recording the number j of fragments i Using j for completely cracking green pellets, counting range is mass>20% of the mass of the primary pellets, if cracks are generated only and the primary pellets are not completely broken, j =1; if the quality can not be found>20% of the mass of the primary pellets, the maximum value of j being 5;
s304, if the green pellets are not broken and only cracks are generated, recording the crack size index 1/y i Y =3 when the crack coverage area exceeds 1/2 of the pellet surface area; when the crack coverage area is 1/4-1/2 of the pellet surface area, y =2; when the crack coverage area is 0-1/4 of the surface area of the pellet, y =1;
s305, when the number of the test samples is 10, calculating to obtain the dropping strength Q of the green pellet for the ith test LX-i The method comprises the following steps:
s4, calculating the falling strength Q of the green pellets LX And average drop strength
Q according to each green pellet LX-i Calculating the number N of the green pellets to obtain Q LX The following were used:
wherein N is the total number of samples to be tested, and N is not less than 10; i ≦ N;
s5, calculating the dispersion V of the falling strength of the green pellets LX The dispersion V of the falling strength of the green pellets in the batch to be inspected LX The following:
s6, according to the dispersion V LX Determining Q obtained in step S2 LX Determining whether the test is continued to obtain qualified Q LX Or until all the test samples are tested, specifically:
s601, firstly testing 10 samples, and obtaining the value Q of the sample LX Dispersion V of LX Stopping the test when the value is less than or equal to 0.2, and enabling the tested data to be qualified;
s602, when V LX If the sample does not meet the requirement, continuously testing 10 samples, and obtaining the overall dispersion V of the sample LX Stopping testing when the value is less than or equal to 0.2+ x, and enabling the tested data to be qualified, wherein x = 0.01-0.05;
s603, analogizing to the above, judging the value V LX Increasing x each time until 50 samples are tested;
s604, when Q LX If the dispersion of (2) does not meet the judgment requirement and the dispersion of (2) continues to increase, the inspection batch does not meet the use requirement.
2. The method for evaluating falling strength of green pellets according to claim 1, wherein the extracted green pellets are tested within 4 hours in step S1.
3. The method for evaluating the falling strength of green pellets according to claim 1, wherein in the step S2, the bottom plate is made of a quenched carbon steel plate with a thickness of more than 1cm, or made of a ceramic plate with the same hardness.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106018073A (en) * | 2016-07-29 | 2016-10-12 | 安徽工业大学 | Dropping strength detection device and method of metallurgical green pellets |
| CN106644776A (en) * | 2016-10-12 | 2017-05-10 | 安徽工业大学 | Method for detecting drop strength of green pellets under motion state |
| CN107991455A (en) * | 2017-10-12 | 2018-05-04 | 江阴兴澄特种钢铁有限公司 | A kind of reliable method examined with research HIC sample crackles |
| CN207937289U (en) * | 2017-11-16 | 2018-10-02 | 陕西臻焱节能环保科技有限公司 | Multi-functional pelletizing falling sphere intensity detecting device |
| CN109855988A (en) * | 2019-02-28 | 2019-06-07 | 西安建筑科技大学 | A kind of measuring method entering furnace pellet/pelletizing drop strength for refining lead skim |
| CN110702571A (en) * | 2019-09-26 | 2020-01-17 | 中冶北方（大连）工程技术有限公司 | Method for measuring total porosity of pellet |
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Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106018073A (en) * | 2016-07-29 | 2016-10-12 | 安徽工业大学 | Dropping strength detection device and method of metallurgical green pellets |
| CN106644776A (en) * | 2016-10-12 | 2017-05-10 | 安徽工业大学 | Method for detecting drop strength of green pellets under motion state |
| CN107991455A (en) * | 2017-10-12 | 2018-05-04 | 江阴兴澄特种钢铁有限公司 | A kind of reliable method examined with research HIC sample crackles |
| CN207937289U (en) * | 2017-11-16 | 2018-10-02 | 陕西臻焱节能环保科技有限公司 | Multi-functional pelletizing falling sphere intensity detecting device |
| CN109855988A (en) * | 2019-02-28 | 2019-06-07 | 西安建筑科技大学 | A kind of measuring method entering furnace pellet/pelletizing drop strength for refining lead skim |
| CN110702571A (en) * | 2019-09-26 | 2020-01-17 | 中冶北方（大连）工程技术有限公司 | Method for measuring total porosity of pellet |
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