Method for quality detection of scrap metal

Abstract

The application relates to the field of metal quality detection, and discloses a quality detection method for waste metal, which comprises the following steps: randomly extracting a preset number of steel chip briquettes, and disassembling and crushing the steel chip briquettes; screening the disassembled and crushed steel chip briquettes to obtain screen overs and screen unders, determining the screen overs proportion and the screen unders proportion in the disassembled and crushed steel chip briquettes, and determining whether the waste metal is adulterated according to the screen unders proportion; preparing a melt cleaning test sample according to the screen overs proportion and the screen unders proportion, determining the water yield of the melt cleaning test sample, and determining the quality of the waste metal according to the water yield. The screen unders proportion of the steel chip briquettes is measured, so that the possibility of adulteration of the steel chip briquette waste metal is effectively avoided; the water yield of the steel chip briquettes is calculated, basic data for waste metal quality determination are provided, human factors are avoided, the accuracy and reliability of metal quality detection are improved, and an important basis for the reasonable utilization of waste metal resources is provided.

Description

Technical Field

[0001] This application relates to the field of metal quality testing, and in particular to a method for testing the quality of scrap metal. Background Technology

[0002] In the steelmaking process, scrap steel plays a crucial role. As a raw material, its quality has a profound impact on the entire smelting process. It not only affects the consumption of steel materials and process costs, but also plays a significant role in the stability of the smelting process and product quality.

[0003] In 2022, the social scrap steel resource generation reached 260 million tons. Several key steps in the scrap steel procurement process cannot be ignored, including loaded truck entry, weighing at the weighbridge, unloading at the scrap steel warehouse, and scrap steel inspection and manual grading. Especially for purchased scrap steel, the quality inspection process generally relies on visual inspection, which is highly susceptible to human error and makes it difficult to accurately distinguish the quality of the scrap steel. This is particularly true for briquetted scrap steel, such as steel chip briquettes and crushed material briquettes, which contain more impurities and powder, making it even more difficult to manage the procurement quality of briquetted scrap steel. The national standard uses the water density test method, but because briquetted scrap steel is easily coated with powder and impurities, leading to an increased overall density and repulsion of moisture, the water density test method cannot accurately reflect the iron content level of briquetted scrap steel and cannot be used as a direct basis for quality judgment.

[0004] Therefore, how to provide an accurate and reliable method for inspecting metal quality and effectively avoid adulteration of steel scrap such as steel chips and briquettes is a problem that needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this application is to provide a method for quality testing of scrap metal, which addresses the problem that existing metal quality assessment methods are not accurate enough.

[0006] To address the aforementioned technical problems, this application provides a method for quality testing of scrap metal, comprising:

[0007] A predetermined number of steel chip blocks are randomly selected, and the steel chip blocks are disassembled and crushed.

[0008] The disassembled and crushed steel chip briquettes are sieved to obtain oversize and undersize materials. The proportions of oversize and undersize materials in the disassembled and crushed steel chip briquettes are determined, and the presence or absence of adulterated scrap metal is determined based on the proportion of undersize materials.

[0009] Prepare a melt-clearing test sample based on the ratio of the oversize material and the ratio of the undersize material, determine the water yield of the melt-clearing test sample, and determine the quality of the scrap metal based on the water yield.

[0010] Optionally, the step of preparing a melt-clearing test sample based on the proportion of material over the sieve and the proportion of material under the sieve, determining the water content of the melt-clearing test sample, and determining the waste metal quality based on the water content includes:

[0011] If the proportion of undersize material is less than a preset value, the oversize material and undersize material are weighed according to the proportion of sieve material, the proportion of undersize material, and the first set weight to obtain the first melt-clearing test sample, the first water output rate of the first melt-clearing test sample is determined, and the waste metal quality is determined according to the first water output rate.

[0012] If the proportion of undersize material is greater than or equal to the preset value, the oversize material and the undersize material are weighed according to the proportion of sieve material, the proportion of sieve material, and the second set weight to obtain a second melt-clearing test sample. The undersize material is weighed separately according to the third set weight to obtain a third melt-clearing test sample. The second water yield of the second melt-clearing test sample and the third water yield of the third melt-clearing test sample are determined respectively, and the waste metal quality is determined according to the second water yield and the third water yield.

[0013] Optionally, determining the waste metal quality based on the first effluent rate includes:

[0014] If the first effluent rate is greater than or equal to the upper limit of the first interval, the quality of the waste metal is determined to be Grade 1;

[0015] If the first effluent rate is within the first range, the quality of the waste metal is determined to be grade II;

[0016] If the first effluent rate is within the second range, the quality of the waste metal is determined to be grade three;

[0017] If the first effluent rate is less than or equal to the lower limit of the second interval, the quality of the waste metal is determined to be intentionally adulterated.

[0018] Optionally, determining the waste metal quality based on the second effluent rate and the third effluent rate includes:

[0019] If the third water discharge rate is greater than or equal to the set water discharge rate, and the second water discharge rate is greater than or equal to the upper limit of the first interval, the quality of the waste metal is determined to be Grade 1.

[0020] If the third effluent rate is greater than or equal to the set effluent rate, and the second effluent rate is within the first interval, the waste metal quality is determined to be grade two.

[0021] If the third effluent rate is greater than or equal to the set effluent rate, and the second effluent rate is within the second interval, the waste metal quality is determined to be grade three.

[0022] If the third water output rate is greater than or equal to the set water output rate, and the second water output rate is less than or equal to the lower limit of the second interval, the quality of the waste metal is determined to be intentionally adulterated.

[0023] If the third water output rate is less than the set water output rate, the quality of the waste metal is determined to be intentionally adulterated.

[0024] Optionally, after disassembling and crushing the steel chip block, the process further includes:

[0025] A predetermined weight of steel chip blocks is randomly selected from the disassembled and crushed steel chip blocks and retained as a sample for re-inspection; wherein the predetermined weight is not less than 2.5 kg.

[0026] Optional, also includes:

[0027] The sample information is marked on the storage device for the re-inspection samples;

[0028] The sample preparation information includes the date, vehicle number, supplier, batch, unloading location, material type, and sampler.

[0029] Optionally, the disassembly and crushing of the steel chip block includes:

[0030] Randomly select multiple steel chip blocks to be crushed from the disassembled steel chip blocks, and the total mass of the multiple steel chip blocks to be crushed shall not be less than 2.5 kg;

[0031] The multiple steel chip blocks to be crushed are then crushed.

[0032] Optionally, determining the effluent rate of the melt-clearing test sample includes:

[0033] Determine the weight of the sample before melting and cleaning, prior to melting and cleaning.

[0034] The melt-clearing test sample is placed in a quartz crucible, and the quartz crucible is placed on a medium-frequency furnace to heat and melt the melt-clearing test sample. After it is completely melted and cooled, the steel slag is separated, and the molten and cooled iron block is weighed to obtain the melt-clearing weight of the melt-clearing test sample.

[0035] The water output rate is determined based on the weight before melting and the weight after melting.

[0036] Optionally, determining the water output rate based on the weight before melting and the weight after melting includes:

[0037] The water output rate is calculated according to a preset formula;

[0038] The preset formula is ω(Fe) = m2 / m1 × 100%;

[0039] Wherein, ω(Fe) is the water output rate, m1 is the weight before melting and cleaning, and m2 is the weight after melting and cleaning.

[0040] Optional, also includes:

[0041] If there is any disagreement regarding the determination of the quality of the scrap metal, a re-inspection shall be conducted using the reserved re-inspection sample.

[0042] This application provides a method for quality testing of scrap metal, comprising: randomly selecting a predetermined number of steel shavings briquettes, and disassembling and crushing the briquettes; sieving the disassembled and crushed steel shavings briquettes to obtain oversize and undersize materials, determining the proportions of oversize and undersize materials in the disassembled and crushed steel shavings briquettes, and determining whether the scrap metal is adulterated based on the undersize proportion; preparing a melt-clearing test sample based on the oversize and undersize proportions, determining the water yield of the melt-clearing test sample, and determining the scrap metal quality based on the water yield. By measuring the undersize proportion of the steel shavings briquettes, the possibility of adulteration of steel shavings briquettes is effectively avoided; by calculating the water yield of the steel shavings briquettes, basic data for scrap metal quality judgment is provided, avoiding human factors and improving the accuracy and reliability of metal quality testing; and providing an important basis for the rational utilization of scrap metal resources. Attached Figure Description

[0043] To more clearly illustrate the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 A flowchart illustrating a method for quality testing of scrap metal provided in this application embodiment. Detailed Implementation

[0045] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this application.

[0046] The core of this application is to provide a quality testing method for scrap metal, which provides an accurate and reliable method for metal quality inspection and effectively avoids the adulteration of scrap steel such as steel chip briquettes.

[0047] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0048] Figure 1 A flowchart of a method for quality testing of scrap metal provided in this application embodiment is shown below. Figure 1 As shown, the quality testing methods for scrap metal include:

[0049] S10: Randomly select a preset number of steel chip blocks and disassemble and crush them.

[0050] S11: The dismantled and crushed steel shavings briquettes are sieved to obtain oversize and undersize materials, respectively. The proportions of oversize and undersize materials in the dismantled and crushed steel shavings briquettes are determined, and the proportion of undersize materials is used to determine whether the scrap metal is adulterated.

[0051] S12: Prepare a melt-clearing test sample based on the proportion of oversize and undersize materials, determine the water yield of the melt-clearing test sample, and determine the quality of the scrap metal based on the water yield.

[0052] This application embodiment does not specify the exact number of samples taken, but typically no less than 5 steel chip blocks are used. The steel chip blocks are then disassembled and crushed. Specifically, multiple steel chip blocks to be crushed are randomly selected from the disassembled blocks, with no fewer than 3 blocks, and the total mass 'a' of these multiple blocks is no less than 2.5 kg. These multiple blocks are then crushed. After disassembly and crushing, the metal is screened using a 10-mesh sieve. The weight of the material on the sieve is measured as 'a1'. The weight of the material under the sieve can be obtained by weighing, or the weight of the material under the sieve can be a-a1, with the percentage of the material on the sieve being a1 / a% and the percentage of the material under the sieve being (a-a1) / a%. If the percentage of the material under the sieve is greater than a set value, it is preliminarily determined that the batch of scrap metal is suspected of being adulterated. Then, a melting test sample is prepared according to the ratio of oversize and undersize materials. This involves weighing a certain weight of oversize and a certain weight of undersize material, mixing them together, and ensuring that the ratio of oversize to undersize material in the melting test sample is consistent with the previously determined ratio. Specifically, the water yield of the melting test sample is determined as follows: The weight of the melting test sample before melting is determined; the melting test sample is placed in a quartz crucible, and the crucible is placed in a medium-frequency furnace to heat and melt the sample. After complete melting and cooling, the slag is separated, and the cooled molten iron block is weighed to obtain the weight of the melting test sample after melting. To expedite the experiment, water cooling can be used, but the cooled iron block should be dried before weighing; the water yield is determined based on the weight before and after melting. The preset formula for calculating the water yield is ω(Fe)=m2 / m1×100%; where ω(Fe) is the water yield, m1 is the weight before melting and cleaning, and m2 is the weight after melting and cleaning. Finally, the quality of the scrap metal can be determined based on the water yield. Here, scrap metal quality refers to the quality of the scrap metal. The water yield can directly reflect the TFe content of briquetted scrap steel. Generally, the higher the water yield, the better the metal quality.

[0053] This application provides a method for quality testing of scrap metal, comprising: randomly selecting a predetermined number of steel shavings briquettes, and disassembling and crushing the briquettes; sieving the disassembled and crushed steel shavings briquettes to obtain oversize and undersize materials, determining the proportions of oversize and undersize materials in the disassembled and crushed steel shavings briquettes, and determining whether the scrap metal is adulterated based on the undersize proportion; preparing a melt-clearing test sample based on the oversize and undersize proportions, determining the water yield of the melt-clearing test sample, and determining the scrap metal quality based on the water yield. By measuring the undersize proportion of the steel shavings briquettes, the possibility of adulteration of steel shavings briquettes is effectively avoided; by calculating the water yield of the steel shavings briquettes, basic data for scrap metal quality determination is provided, avoiding human factors, improving the accuracy and reliability of metal quality testing, and providing an important basis for the rational utilization of scrap metal resources.

[0054] Based on the above embodiments, this application embodiment prepares a melt-clearing test sample according to the proportion of oversize material and the proportion of undersize material, determines the water yield of the melt-clearing test sample, and determines the waste metal quality based on the water yield, including: if the proportion of undersize material is less than a preset value, weigh the oversize material and undersize material according to the proportion of oversize material, the proportion of undersize material, and a first set weight to obtain a first melt-clearing test sample, determine the first water yield of the first melt-clearing test sample, and determine the waste metal quality based on the first water yield; if the proportion of undersize material is greater than or equal to a preset value, weigh the oversize material and undersize material according to the proportion of oversize material, the proportion of undersize material, and a second set weight to obtain a second melt-clearing test sample, separately weigh the undersize material of a third set weight to obtain a third melt-clearing test sample, determine the second water yield of the second melt-clearing test sample and the third water yield of the third melt-clearing test sample, and determine the waste metal quality based on the second water yield and the third water yield.

[0055] For ease of understanding, further explanation is provided below. If the undersize proportion is less than 20%, weigh a first set weight of the mixture of oversize and undersize, i.e., the first melt-clearing test sample. The proportions of oversize and undersize in this first melt-clearing test sample should be consistent with the proportions measured above, and the first set weight should not be less than 1 kg. Then, test the water yield of the first melt-clearing test sample according to the method provided above. If the undersize proportion is greater than 20%, weigh a second set weight of the mixture of oversize and undersize, i.e., the second melt-clearing test sample. The proportions of oversize and undersize in this second melt-clearing test sample should be consistent with the proportions measured above, and the second set weight should not be less than 1 kg. Then, test the water yield of the second melt-clearing test sample according to the method provided above. Furthermore, a third set weight of undersize needs to be weighed separately to obtain the third melt-clearing test sample, with the third set weight not less than 1 kg. Then, test the water yield of the third melt-clearing test sample according to the method provided above.

[0056] In this embodiment, when the proportion of undersize material is less than a preset value, it indicates that there is less powder in the waste metal, and the possibility of adulteration is small. Therefore, it is not necessary to separately test the water yield of the undersize material, thus improving efficiency. When the proportion of undersize material is greater than or equal to the preset value, it indicates that there is more powder in the waste metal, and there is a possibility of adulteration. To further ensure accuracy, it is necessary not only to test the water yield of the mixture of oversize and undersize material, but also to separately test the water yield of the undersize material.

[0057] Based on the above embodiments, this application provides a method for determining the quality of waste metal based on a first effluent rate, and a method for determining the quality of waste metal based on a second effluent rate and a third effluent rate.

[0058] The quality of scrap metal is determined based on the first effluent rate, including: if the first effluent rate is greater than or equal to the upper limit of the first interval, the scrap metal quality is determined to be Grade 1; if the first effluent rate is within the first interval, the scrap metal quality is determined to be Grade 2; if the first effluent rate is within the second interval, the scrap metal quality is determined to be Grade 3; if the first effluent rate is less than or equal to the lower limit of the second interval, the scrap metal quality is determined to be intentionally adulterated.

[0059] The quality of scrap metal is determined based on the second and third effluent rates, including: if the third effluent rate is greater than or equal to the set effluent rate, and the second effluent rate is greater than or equal to the upper limit of the first interval, the scrap metal quality is determined to be Grade 1; if the third effluent rate is greater than or equal to the set effluent rate, and the second effluent rate is within the first interval, the scrap metal quality is determined to be Grade 2; if the third effluent rate is greater than or equal to the set effluent rate, and the second effluent rate is within the second interval, the scrap metal quality is determined to be Grade 3; if the third effluent rate is greater than or equal to the set effluent rate, and the second effluent rate is less than or equal to the lower limit of the second interval, the scrap metal quality is determined to be intentionally adulterated. If the third effluent rate is less than the set effluent rate, the scrap metal quality is determined to be intentionally adulterated.

[0060] Specifically, please refer to Table 1. When the proportion of undersize material is less than 20%, the undersize water yield (third water yield) does not need to be tested. If the sample water yield (first water yield) is greater than or equal to 95%, the waste metal quality is grade one; if the sample water yield (first water yield) is between 93% and 95%, the waste metal quality is grade two; if the sample water yield (first water yield) is between 91% and 93%, the waste metal quality is grade three; if the sample water yield (first water yield) is less than or equal to 91%, the waste metal quality is intentionally adulterated. When the proportion of undersize material is greater than or equal to 20%, and the undersize water yield (third water yield) is greater than or equal to 85%, if the sample water yield (second water yield) is greater than or equal to 95%, the waste metal quality is grade one; if the sample water yield (second water yield) is between 93% and 95%, the waste metal quality is grade two; if the sample water yield (second water yield) is between 91% and 93%, the waste metal quality is grade three; if the sample water yield (second water yield) is less than or equal to 91%, the waste metal quality is intentionally adulterated; however, when the proportion of undersize material is greater than or equal to 20%, and the undersize water yield (third water yield) is less than 85%, there is no need to judge the size of the second water yield, and it can be directly regarded as intentional adulteration.

[0061] Table 1. Quality Grades of Scrap Metal

[0062]

[0063] The embodiments of this application determine the quality grade of waste metal based on the water output rate, which can intuitively reflect the quality of waste metal, assist staff in judgment, and reduce subjective judgment due to human factors.

[0064] Based on the above embodiments, after disassembling and crushing the steel chip block, this application embodiment further includes: randomly selecting a steel chip block of a preset weight from the disassembled and crushed steel chip block and storing it as a sample for re-inspection; wherein, the preset weight is not less than 2.5 kg.

[0065] Furthermore, the storage device for the re-inspection samples can be labeled with sample information, including the date, vehicle number, supplier, batch number, unloading location, material type, and sampler. This information facilitates subsequent traceability.

[0066] If there is any objection to the test results of the effluent rate, a retest can be conducted using the prepared sample. For specific procedures, please refer to the effluent rate test method described above.

[0067] To gain a clearer understanding of this application, we will provide further details below, using specific application scenarios as examples.

[0068] Case 1:

[0069] 1. Sample Preparation: Randomly select 5 steel chip blocks from the incoming steel chip blocks, disassemble them into smaller pieces, and then randomly select 3 of these smaller pieces, totaling 2846.3g. These smaller pieces are then completely crushed for sample preparation. Simultaneously, randomly select one piece (weighing no less than 2.5kg) from the disassembled and crushed blocks for retention as a backup sample for re-inspection in case of anomalies. Label the backup sample with the date, vehicle number, supplier, batch number, unloading location, material type, and sampler information, and place it in a monitored area. Once the sample melt-clearing test is satisfactory, the retained sample can be disposed of. Samples with discrepancies in the melt-clearing test will be disposed of after re-inspection.

[0070] 2. First, screen the completely crushed steel chip briquettes using a 10-mesh sieve. Weigh the briquettes; the weight of the material over the sieve is 2439.6g, and the weight of the material under the sieve is 406.7g. The oversize percentage of this batch of incoming steel chip briquettes is 2439.6 / 2846.3 = 85.71%, and the undersize percentage is 406.7 / 2846.3 = 14.29%.

[0071] 3. Since the proportion of undersize material (14.29%) is less than 20%, the sample was weighed according to the actual proportion of steel chip briquettes. The mass of oversize material (857.1g) and undersize material (142.9g) totaled 1000g as the melt-clearing test sample. The date, vehicle number, supplier, batch, unloading location, material type, sampler, and sample weight information were recorded.

[0072] 4. Then, place the molten steel sample into a quartz crucible and heat it in a medium-frequency furnace until fully melted. After the scrap steel in the crucible has completely melted, stop heating in the medium-frequency furnace and use clamps to place the crucible in the cooling zone for natural cooling. After cooling, separate the steel slag and take the molten and cooled iron block, weighing and recording the weight as 94.7g. The water yield of this steel chip briquettes is ω(Fe) = 94.7 / 1000 = 94.7%.

[0073] 5. Quality assessment of steel cutting blocks: The steel cutting blocks with a water yield of 94.7% are classified as Grade II according to Table 1, with a water yield between 93% and 95%. Water yield inspection.

[0074] 6. Settlement: When the water output rate is lower than 95%, and 91% < water output rate ≤ 95%, the price will be reduced by 30 yuan / ton for every 1% decrease; the water output rate in Case 1 is 94.7%, and the amount of miscellaneous tonnage is deducted = (95-94.7)×30 / current period steel chip briquettes winning bid price × net weight of the steel chip briquettes of the truck.

[0075] 7. Information Upload

[0076] All data information from the meltblown material inspection, including the date, vehicle number, supplier, batch number, unloading location, material type, and production rate, is promptly uploaded to the company by dedicated meltblown material inspection personnel. Impurities are deducted according to grade for settlement. If any abnormalities are found during meltblown material inspection, the dedicated personnel remind the sampling personnel to preserve the samples for re-inspection.

[0077] 8. Objection and re-inspection

[0078] If a re-inspection is required due to objections, after obtaining approval from relevant leaders, the re-inspection sample shall be remade according to the steel cutting briquette inspection process, and then re-inspected.

[0079] Case 2:

[0080] 1. Sample Preparation: Randomly select 5 steel chip blocks from the incoming steel chip blocks, disassemble them into smaller pieces, and then randomly select 3 of these smaller pieces, totaling 3027.6g. These smaller pieces are then completely crushed for sample preparation. Simultaneously, randomly select one piece (weighing no less than 2.5kg) from the disassembled and crushed blocks for retention as a backup sample in case of anomalies. Label the backup sample with the date, vehicle number, supplier, batch number, unloading location, material type, and sampler information, and place it in a monitored area. Once the sample melt-clearing test is satisfactory, the retained sample can be disposed of. Samples with discrepancies in the melt-clearing test will be disposed of after a retest.

[0081] 2. First, screen the completely crushed steel chip briquettes using a 10-mesh sieve. Weigh the briquettes; the weight of the material passing through the sieve is 2390.8g, and the weight of the material passing through the sieve is 636.8g. The proportion of the material passing through the sieve in this batch of incoming steel chip briquettes is: 2390.8 / 3027.6 = 78.97%, and the proportion of the material passing through the sieve is: 636.8 / 3027.6 = 21.03%.

[0082] 4. Since the proportion of undersize material (21.03%) is greater than 20%, the sample was weighed according to the actual proportion of the steel chip briquettes. The mass of oversize material (789.7g) and undersize material (210.3g), totaling 1000g, was used as the melt flow test sample. The date, vehicle number, supplier, batch number, unloading location, material type, sampler, and sample weight information were recorded.

[0083] 5. In addition, prepare 1000g of the undersize sample, melt it, and fill in the record with the date, vehicle number, supplier, batch, unloading location, material type, sampler, and sample weight information.

[0084] 6. Place the two smelting test samples into quartz crucibles and heat them in an induction furnace until fully melted. After the scrap steel in the quartz crucibles is completely melted, stop heating in the induction furnace and place the crucibles in the cooling zone to cool naturally. After cooling, separate the steel slag and take the smelted and cooled iron block, weighing and recording the weight as 91.9g. The mass of 1000g of the sieve material after smelting is 86.6g. Since the water content of the sieve material is 86.6%, which is greater than 85%, the water content of the steel chip briquettes is: ω(Fe)=91.9 / 1000=91.9%.

[0085] 5. Quality assessment of steel cutting blocks: The water yield of the steel cutting blocks in this study was 91.9%. Referring to Table 1, blocks with a water yield between 91% and 93% are classified as Grade III.

[0086] 6. Settlement: In Case 2, the undersize output ratio is 21.3%, which exceeds 20%. The undersize needs to be melted and tested to determine the water content, which is 86.6%, greater than 85%. Therefore, the settlement is based on a water content of 91.9% for the steel chip briquettes. According to the rule that when the water content is lower than 95%, and 91% < water content ≤ 95%, the price will be reduced by 30 yuan / ton for every 1% decrease. The water content of Case 2 is 91.9%, and the deduction for impurities is calculated as (95-91.9)×30 / current period steel chip briquettes winning bid price × net weight of the steel chip briquettes in this truck.

[0087] 7. Information Upload

[0088] All data information from the meltblown material inspection, including the date, vehicle number, supplier, batch number, unloading location, material type, and production rate, is promptly uploaded to the company by dedicated meltblown material inspection personnel. Impurities are deducted according to grade for settlement. If any abnormalities are found during meltblown material inspection, the dedicated personnel remind the sampling personnel to preserve the samples for re-inspection.

[0089] 8. Objection and re-inspection

[0090] If a re-inspection is required due to objections, after obtaining approval from relevant leaders, the melt-clear sample (inspection sample) shall be remade in accordance with the inspection procedure for steel cutting blocks, and then re-inspected.

[0091] This application first measures the proportion of undersize material in steel shavings briquettes to reduce the possibility of adulteration. Based on differences in the undersize material proportion, targeted adjustments were made, and different testing methods were developed to more accurately reflect the quality of steel shavings briquettes. Secondly, steel shavings briquette samples were melted and purified in a medium-frequency furnace using a quartz crucible. The water content of the steel shavings briquettes was calculated, providing fundamental data for subsequent quality assessment and an important basis for the rational utilization of scrap steel resources. This helps enterprises make accurate decisions and reduce losses.

[0092] The advantages of this application are that it ensures the independence of sampling, inspection, and acceptance grading of steel shavings briquettes, guarantees the rationality of the melt-clearing inspection of steel cutting briquettes, solves the problem of significant interference from visual observation and human factors, reduces manual grading steps, improves efficiency, and the water yield directly reflects the TFe content of briquetted scrap steel, making it an effective method for determining scrap metal quality, avoiding adulteration, and meeting the acceptance requirements for incoming steel shavings briquettes. By measuring the undersize ratio of steel shavings briquettes and developing targeted inspection methods, accurate determination of scrap steel quality is achieved. This method is simple to operate, highly practical, and solves the problem of significant variations due to visual interference in the previous inspection of steel shavings briquettes. By directly calculating the water yield of steel shavings briquettes, a reliable basis for scrap steel quality determination is provided. This helps to avoid adulteration of steel shavings briquettes and improves the quality of incoming steel cutting scrap steel. It provides a new solution for scrap metal inspection in the metallurgical industry and has high practical value. It can promote the rational utilization of waste metal resources, reduce losses for enterprises, and has good social and economic benefits.

[0093] The above provides a detailed description of a method for quality inspection of scrap metal provided in this application. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this application.

[0094] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A method for quality inspection of scrap metal, characterized in that, include: A predetermined number of steel chip blocks are randomly selected, and the steel chip blocks are disassembled and crushed. The disassembled and crushed steel chip briquettes are sieved to obtain oversize and undersize materials. The proportions of oversize and undersize materials in the disassembled and crushed steel chip briquettes are determined, and the presence or absence of adulterated scrap metal is determined based on the proportion of undersize materials. Prepare a melt-clearing test sample based on the ratio of the oversize material and the ratio of the undersize material, determine the water yield of the melt-clearing test sample, and determine the waste metal mass based on the water yield. The process of preparing a melt-clearing test sample based on the proportion of material remaining on the sieve and the proportion of material passing through the sieve, determining the water yield of the melt-clearing test sample, and determining the quality of the scrap metal based on the water yield includes: If the proportion of undersize material is less than a preset value, the oversize material and undersize material are weighed according to the proportion of sieve material, the proportion of undersize material and the first set weight respectively to obtain the first melt-clearing test sample, the first water output rate of the first melt-clearing test sample is determined, and the waste metal quality is determined according to the first water output rate. If the proportion of undersize material is greater than or equal to the preset value, the oversize material and the undersize material are weighed according to the proportion of sieve material, the proportion of sieve material, and the second set weight to obtain a second melt-clearing test sample. The undersize material is weighed separately according to the third set weight to obtain a third melt-clearing test sample. The second water yield of the second melt-clearing test sample and the third water yield of the third melt-clearing test sample are determined respectively. The waste metal quality is determined according to the second water yield and the third water yield. The step of determining the waste metal quality based on the first effluent rate includes: If the first effluent rate is greater than or equal to the upper limit of the first interval, the quality of the waste metal is determined to be Grade 1; If the first effluent rate is within the first range, the quality of the waste metal is determined to be grade II; If the first effluent rate is within the second range, the quality of the waste metal is determined to be grade three; If the first effluent rate is less than or equal to the lower limit of the second interval, the quality of the waste metal is determined to be intentionally adulterated. The determination of waste metal quality based on the second effluent rate and the third effluent rate includes: If the third water discharge rate is greater than or equal to the set water discharge rate, and the second water discharge rate is greater than or equal to the upper limit of the first interval, the quality of the waste metal is determined to be Grade 1. If the third effluent rate is greater than or equal to the set effluent rate, and the second effluent rate is within the first interval, the waste metal quality is determined to be grade two. If the third effluent rate is greater than or equal to the set effluent rate, and the second effluent rate is within the second interval, the waste metal quality is determined to be grade three. If the third water output rate is greater than or equal to the set water output rate, and the second water output rate is less than or equal to the lower limit of the second interval, the quality of the waste metal is determined to be intentionally adulterated. If the third water output rate is less than the set water output rate, the quality of the waste metal is determined to be intentionally adulterated.

2. The method for quality testing of scrap metal according to claim 1, characterized in that, After disassembling and crushing the steel chip block, the process further includes: A predetermined weight of steel chip blocks is randomly selected from the disassembled and crushed steel chip blocks and retained as a sample for re-inspection; wherein the predetermined weight is not less than 2.5 kg.

3. The method for quality testing of scrap metal according to claim 2, characterized in that, Also includes: The sample information is marked on the storage device for the re-inspection samples; The sample preparation information includes the date, vehicle number, supplier, batch, unloading location, material type, and sampler.

4. The method for quality inspection of scrap metal according to claim 1, characterized in that, The dismantling and crushing of the steel chip block includes: Randomly select multiple steel chip blocks to be crushed from the disassembled steel chip blocks, and the total mass of the multiple steel chip blocks to be crushed shall not be less than 2.5 kg; The multiple steel chip blocks to be crushed are then crushed.

5. The method for quality testing of scrap metal according to claim 1, characterized in that, Determining the water yield of the melt-clearing test sample includes: Determine the weight of the sample before melting and cleaning, prior to melting and cleaning. The melt-clearing test sample is placed in a quartz crucible, and the quartz crucible is placed on a medium-frequency furnace to heat and melt the melt-clearing test sample. After it is completely melted and cooled, the steel slag is separated, and the molten and cooled iron block is weighed to obtain the melt-clearing weight of the melt-clearing test sample. The water output rate is determined based on the weight before melting and the weight after melting.

6. The method for quality inspection of scrap metal according to claim 5, characterized in that, Determining the water output rate based on the weight before melting and the weight after melting includes: The water output rate is calculated according to a preset formula; The preset formula is ω(Fe) = m2 / m1 × 100%; Wherein, ω(Fe) is the water output rate, m1 is the weight before melting and cleaning, and m2 is the weight after melting and cleaning.

7. The method for quality inspection of scrap metal according to claim 2, characterized in that, Also includes: If there is any disagreement regarding the determination of the quality of the scrap metal, a re-inspection shall be conducted using the reserved re-inspection sample.

Images