A high carbon secondary battery waste detection sample pretreatment method

Abstract

The present application relates to the technical field of battery recycling, and provides a high-carbon secondary battery waste detection sample pretreatment method, comprising the following steps: step 1: performing oxygen-containing high-temperature calcination on a high-carbon secondary battery waste sample after preliminary grinding; step 2: grinding and sieving the calcined sample; step 3: taking part of the sieved sample, performing low-temperature hydrochloric acid dissolution, and then performing high-temperature perchloric acid and nitric acid dissolution; and step 4: cooling the acid-dissolved sample, moving it into a volumetric flask, and then filtering or clarifying to obtain a to-be-detected solution by full volume or dilution. The present application can realize sufficient dissolution of a high-carbon secondary battery waste detection sample, improve the uniformity of the sample, and improve the stability of the detection result.

Description

Technical Field

[0001] This invention relates to the field of battery recycling technology, and in particular to a sample pretreatment method for testing high-carbon secondary battery waste. Background Technology

[0002] Battery recyclable material refers to the mixture obtained after waste batteries have undergone dismantling, crushing and other processes. It is a mixture of metal oxides, elemental metals, graphite and other materials. It is an important secondary resource and contains valuable metal elements such as nickel, cobalt, copper, manganese, aluminum and lithium. It is often used as a raw material for metal recycling.

[0003] Nickel, cobalt, manganese, and lithium in the sample generally exist in the form of composite oxides and other forms, copper and aluminum exist in the form of metals or oxides, and carbon exists in the form of organic carbon or graphite.

[0004] Due to the requirements of recycling processes and value assessment, battery recycled materials generally need to be analyzed for their valuable metals. This necessitates effective sample treatment to ensure that the elements to be measured are completely dissolved in the solution, thereby guaranteeing the accuracy of the test results. Current technology, following YS / T1342 "Chemical Analysis Methods for Secondary Battery Waste," uses aqua regia to decompose the battery recycled materials before analysis.

[0005] Due to the complexity of the forms in which metals exist in recycled secondary battery materials and the problems of metal encapsulation caused by electrochemical reactions during battery use, conventional acid decomposition methods, including YS / T1342, cannot completely decompose secondary battery waste samples. At the same time, due to the presence of copper, aluminum alloys, or metal particles, conventional methods cannot solve the problem of sample uniformity, resulting in poor stability of test results and inability to accurately assess the value of materials. Therefore, it is necessary to research and invent more reliable sample pretreatment methods. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a sample pretreatment method for high-carbon secondary battery waste, which can improve the uniformity of the sample and achieve full dissolution of the high-carbon secondary battery waste sample, thereby improving the accuracy and stability of the test results.

[0007] The technical solution of this invention is as follows:

[0008] A sample pretreatment method for testing high-carbon secondary battery waste includes the following steps:

[0009] Step 1: After preliminary grinding, the high-carbon secondary battery waste sample is subjected to aerobic high-temperature calcination, which oxidizes the metals into oxides and decomposes most of the carbon into carbon dioxide.

[0010] Step 2: Grind and sieve the calcined sample;

[0011] Step 3: Weigh a portion of the sieved sample, dissolve it in hydrochloric acid at low temperature, and then dissolve it in perchloric acid and nitric acid at high temperature;

[0012] Step 4: After cooling the acid-dissolved sample, transfer it to a volumetric flask and make up to volume. Filter or clarify the solution and then dilute or concentrate it to obtain the solution to be tested.

[0013] Optionally, in step 1, the high-carbon secondary battery waste sample is initially ground and then subjected to aerobic high-temperature calcination, specifically including: weighing 5-100g of the initially ground high-carbon secondary battery waste sample and placing it in a crucible, then placing the crucible in a high-temperature furnace and calcining it at 850-1200℃ for 30-60min.

[0014] Optionally, in step 1, the crucible is one of a porcelain crucible, an iron crucible, or a high-alumina crucible.

[0015] Optionally, in step 1, the furnace door is opened 2-4 times during the aerobic calcination process.

[0016] Optionally, in step 2, the calcined sample is ground and sieved, specifically including: grinding the calcined sample in a sample preparation machine or grinder for 1-10 minutes, and then sieving it through a 120-200 mesh sieve.

[0017] Optionally, in step 3, a portion of the sieved sample is weighed and dissolved in hydrochloric acid at low temperature, followed by dissolution in perchloric acid and nitric acid at high temperature. Specifically, this includes: weighing 0.05-0.50g of the sieved sample, adding 10-40mL of hydrochloric acid and dissolving at 100-150℃ for 10-50min, then adding 1-5mL of perchloric acid and 5-25mL of nitric acid and dissolving at 300-350℃.

[0018] Optionally, in step 3, the low-temperature dissolution of hydrochloric acid and the high-temperature dissolution of perchloric acid and nitric acid are both carried out in a glass beaker. The high-temperature dissolution of perchloric acid and nitric acid is carried out by heating on a hot plate until white fumes of perchloric acid are emitted. After the white fumes are completely emitted, the beaker is removed and cooled. Then, 2-5 mL of dilute hydrochloric acid (1+1) and 40-60 mL of water are added and the mixture is heated to boiling.

[0019] Optionally, in step 4, after cooling the acid-dissolved sample, it is transferred to a volumetric flask and brought to volume. After filtration or clarification, the solution is obtained by full volume or dilution. Specifically, this includes: after cooling the acid-dissolved sample, it is transferred to a 100mL or 200mL volumetric flask and brought to volume. After dry filtration with filter paper or filter membrane, or clarification, the corresponding filtrate or clarified solution is obtained by full volume or dilution according to the element content to obtain the solution to be tested.

[0020] Optionally, the content of lithium, cobalt, manganese, nickel, iron, and copper in the test solution is determined by flame atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry, and the mass percentage of the analyte is determined as W. x =ρ*V*n / m*K; where ρ is the measured concentration of the element to be measured in mg / L, V is the volume of the fixed volume in step 4, n is the dilution factor (n = 1 when full volume determination is used), m is the amount of sample weighed in step 3 in g, and K is the mass ratio of the sample before and after calcination in step 1.

[0021] The beneficial effects of this invention are as follows:

[0022] This invention involves preliminary grinding of high-carbon secondary battery waste samples followed by aerobic high-temperature calcination, grinding and sieving of the calcined samples, dissolving a portion of the sieved sample in hydrochloric acid at low temperature, then dissolving it in perchloric acid and nitric acid at high temperature, cooling the acid-dissolved sample, transferring it to a volumetric flask for volume adjustment, filtering or clarifying, and then diluting or refining to obtain the solution to be tested. This method can be used for sample processing in the detection of high-carbon materials during the secondary battery recycling process. The preliminary grinding of the sample, followed by aerobic high-temperature calcination, decomposes most of the carbon and converts copper and aluminum metals in the sample into oxides. Grinding the calcined sample ensures its homogeneity. The grinding of the sample, followed by low-temperature dissolution in hydrochloric acid and further high-temperature dissolution in perchloric acid and nitric acid, fully dissolves lithium, cobalt, manganese, and nickel in the sample, improving sample homogeneity and achieving complete dissolution of high-carbon secondary battery waste samples, thus improving the accuracy and stability of the test results. Detailed Implementation

[0023] The present invention will be further described below with reference to specific embodiments.

[0024] Example 1

[0025] Weigh 10g of the pre-ground high-carbon secondary battery waste sample and place it in a 50mL pre-weighed porcelain crucible. Place the crucible in a high-temperature furnace and heat it to 900℃ for aerobic calcination for 30min, so that the carbon in it decomposes into carbon dioxide and the copper and aluminum metals are converted into copper oxide and aluminum oxide. Specifically, the furnace door is opened twice during the aerobic calcination process. First, hold the temperature for 15min, then open the furnace door for 30s, continue to hold the temperature for 10min, then open the furnace door for 30s, continue to hold the temperature for 5min, turn off the power of the high-temperature furnace, open the furnace door, and wait for the temperature of the high-temperature furnace to drop below 300℃. Take out the crucible, place it in a desiccator, and cool it to room temperature. Accurately weigh the crucible and the sample.

[0026] After grinding the calcined sample in a sample preparation machine for 2 minutes, it was then sieved through a 150-mesh sieve to further homogenize the sample. The sieved sample was then placed into a sample bag.

[0027] Weigh 0.20g of the sieved sample into a 400mL glass beaker, moisten the sample with water, add 20mL of concentrated hydrochloric acid, and dissolve it for 30min on a hot plate set to 150℃. Then add 2mL of perchloric acid and 10mL of nitric acid, raise the temperature of the hot plate to 350℃, and dissolve until white fumes of perchloric acid are emitted. After the white fumes are completely removed, remove the beaker and cool it. Add 5mL of dilute hydrochloric acid (1+1) and 50mL of pure water, and heat to boiling for 5min.

[0028] After the sample is dissolved in acid, it is cooled and transferred to a 200mL volumetric flask and diluted to volume. After filtration with filter paper, the corresponding filtrate is obtained by either full-volume or diluted according to the element content to obtain the solution to be tested.

[0029] The content of lithium, cobalt, manganese, nickel, iron, and copper in the test solution was determined by flame atomic absorption spectrometry. The calculation of the results must account for calcination losses. Specifically, the mass percentage of the analyte is W. x =ρ*V*n / m*K; where ρ is the measured concentration of the element to be measured in mg / L, V is the volume of the fixed volume in step 4, n is the dilution factor (n = 1 when full volume determination is used), m is the amount of sample weighed in step 3 in g, and K is the mass ratio of the sample before and after calcination in step 1.

[0030] Example 2

[0031] Weigh 20g of the pre-ground high-carbon secondary battery waste sample and place it in a 100mL pre-weighed porcelain crucible. Place the crucible in a high-temperature furnace and heat it to 950℃ for aerobic calcination for 30min, so that the carbon in it decomposes into carbon dioxide and the copper and aluminum metals are converted into copper oxide and aluminum oxide. Specifically, the furnace door is opened twice during the aerobic calcination process. First, hold the temperature for 10min, then open the furnace door for 30s, continue to hold the temperature for 10min, then open the furnace door for 30s, continue to hold the temperature for 10min, then open the furnace door again for 30s, and continue to hold the temperature for 10min. Turn off the power to the high-temperature furnace, open the furnace door, and wait for the temperature of the high-temperature furnace to drop below 300℃. Take out the crucible, place it in a desiccator, and cool it to room temperature. Accurately weigh the crucible and the sample.

[0032] After calcination, the sample is ground in a sample preparation machine or grinder for 3 minutes, then sieved through a 120-mesh sieve to further homogenize the sample. The sieved sample is then placed into a sample bag.

[0033] Weigh 0.10g of the sieved sample into a 400mL glass beaker, moisten the sample with water, add 15mL of concentrated hydrochloric acid, and dissolve it for 40min on a hot plate set to 150℃. Then add 3mL of perchloric acid and 15mL of nitric acid, raise the temperature of the hot plate to 350℃, and dissolve until white fumes of perchloric acid are emitted. After the white fumes are cleared, remove the beaker and cool it. Add 2mL of dilute hydrochloric acid (1+1) and 50mL of pure water, and heat to boiling for 5min.

[0034] After the sample is dissolved in acid, it is cooled and transferred to a 100mL volumetric flask and diluted to volume. After filtration with filter paper or natural precipitation, the corresponding filtrate or clarified liquid is used to obtain the solution to be tested by full or dilution according to the element content.

[0035] The content of lithium, cobalt, manganese, nickel, iron, and copper in the test solution was determined by inductively coupled plasma atomic emission spectrometry. The calculation of the results must account for calcination losses. Specifically, the mass percentage of the analyte is W. x =ρ*V*n / m*K; where ρ is the measured concentration of the element to be measured in mg / L, V is the volume of the fixed volume in step 4, n is the dilution factor (n = 1 when full volume determination is used), m is the amount of sample weighed in step 3 in g, and K is the mass ratio of the sample before and after calcination in step 1.

[0036] Example 3

[0037] Weigh 5g of the pre-ground high-carbon secondary battery waste sample and place it in a 50mL pre-weighed iron crucible. Put the crucible into a high-temperature furnace and heat it to 850℃ for aerobic calcination for 40min, so that the carbon in it decomposes into carbon dioxide and the copper and aluminum metals are converted into copper oxide and aluminum oxide. Specifically, the furnace door is opened 3 times during the aerobic calcination process: first, hold the temperature for 10min, open the furnace door for 30s, continue to hold the temperature for 10min, open the furnace door for 30s, continue to hold the temperature for 10min, open the furnace door for 30s, continue to hold the temperature for 10min, open the furnace door for 30s, continue to hold the temperature for 10min, turn off the power of the high-temperature furnace, open the furnace door, and wait for the temperature of the high-temperature furnace to drop below 300℃. Take out the crucible, place it in a desiccator, cool it to room temperature, and accurately weigh the crucible and the sample.

[0038] After calcination, the sample is ground in a sample preparation machine or grinder for 1 minute, then sieved through a 120-mesh sieve to further homogenize the sample. The sieved sample is then placed into a sample bag.

[0039] Weigh 0.05g of the sieved sample into a 400mL glass beaker, moisten the sample with water, add 10mL of concentrated hydrochloric acid, and dissolve it for 30min on a hot plate set to 100℃. Then add 1mL of perchloric acid and 5mL of nitric acid, raise the temperature of the hot plate to 300℃, and dissolve until white fumes of perchloric acid are emitted. After the white fumes are completely removed, remove the beaker and cool it. Add 2mL of dilute hydrochloric acid (1+1) and 40mL of pure water, and heat to boiling for 5min.

[0040] After the sample is dissolved in acid, it is removed, cooled, and transferred to a 100 mL volumetric flask. The volume is then adjusted to a final volume. After natural precipitation, the corresponding clarified solution is obtained by either full or diluted according to the elemental content to obtain the solution to be tested.

[0041] The content of lithium, cobalt, manganese, nickel, iron, and copper in the test solution was determined by flame atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry. The calculation of the results must consider calcination losses. Specifically, the mass percentage of the analyte is W. x =ρ*V*n / m*K; where ρ is the measured concentration of the element to be measured in mg / L, V is the volume of the fixed volume in step 4, n is the dilution factor (n = 1 when full volume determination is used), m is the amount of sample weighed in step 3 in g, and K is the mass ratio of the sample before and after calcination in step 1.

[0042] Example 4

[0043] Weigh 100g of the pre-ground high-carbon secondary battery waste sample and place it in a 50mL pre-weighed high-alumina crucible. Place the crucible in a high-temperature furnace and heat it to 1200℃ for aerobic calcination for 50min, so that the carbon in it decomposes into carbon dioxide and the copper and aluminum metals are converted into copper oxide and aluminum oxide. Specifically, the furnace door is opened 4 times during the aerobic calcination process: first, hold the temperature for 20min, open the furnace door for 30s, continue to hold the temperature for 5min, then open the furnace door for 30s, continue to hold the temperature for 5min, then open the furnace door for 30s, continue to hold the temperature for 10min, then open the furnace door for 30s, continue to hold the temperature for 10min, then turn off the power of the high-temperature furnace, open the furnace door, and wait for the temperature of the high-temperature furnace to drop below 300℃. Remove the crucible, place it in a desiccator, and cool it to room temperature. Accurately weigh the crucible and the sample.

[0044] After calcination, the sample is ground in a sample preparation machine or grinder for 10 minutes, then sieved through a 200-mesh sieve to further homogenize the sample. The sieved sample is then placed in a sample bag.

[0045] Weigh 0.50g of the sieved sample into a 400mL glass beaker, moisten the sample with water, add 40mL of concentrated hydrochloric acid, and dissolve it for 50min on a hot plate set to 150℃. Then add 5mL of perchloric acid and 25mL of nitric acid, raise the temperature of the hot plate to 350℃, and dissolve until white fumes of perchloric acid are emitted. After the white fumes are completely removed, remove the beaker and cool it. Add 5mL of dilute hydrochloric acid (1+1) and 60mL of pure water, and heat to boiling for 5min.

[0046] After the sample is dissolved in acid, it is cooled and transferred to a 200 mL volumetric flask and diluted to volume. After filtration through a membrane, the corresponding filtrate is either fully diluted or diluted according to the element content to obtain the solution to be tested.

[0047] The content of lithium, cobalt, manganese, nickel, iron, and copper in the test solution was determined by flame atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry. The calculation of the results must consider calcination losses. Specifically, the mass percentage of the analyte is W. x=ρ*V*n / m*K; where ρ is the measured concentration of the element to be measured in mg / L, V is the volume of the fixed volume in step 4, n is the dilution factor (n = 1 when full volume determination is used), m is the amount of sample weighed in step 3 in g, and K is the mass ratio of the sample before and after calcination in step 1.

[0048] Obviously, the above embodiments are merely some, not all, of the embodiments of the present invention. The above embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention. Based on the above embodiments, all other embodiments obtained by those skilled in the art without inventive effort, that is, all modifications, equivalent substitutions, and improvements made within the spirit and principle of this application, fall within the scope of protection claimed by the present invention.

Claims

1. A method for pretreatment of high-carbon secondary battery waste samples, characterized in that, Includes the following steps: Step 1: After preliminary grinding of the high-carbon secondary battery waste sample, it is subjected to aerobic high-temperature calcination. Specifically, 5-100g of the preliminary ground high-carbon secondary battery waste sample is placed in a crucible, and the crucible is placed in a high-temperature furnace and calcined at 850-1200℃ for 30-60 minutes. Step 2: Grind and sieve the calcined sample; Step 3: Weigh a portion of the sieved sample and dissolve it in hydrochloric acid at low temperature, followed by dissolving it in perchloric acid and nitric acid at high temperature. Specifically, weigh 0.05-0.50g of the sieved sample, add 10-40mL of hydrochloric acid and dissolve it at 100-150℃ for 10-50min, then add 1-5mL of perchloric acid and 5-25mL of nitric acid and dissolve it at 300-350℃. The low-temperature dissolution with hydrochloric acid and the high-temperature dissolution with perchloric acid and nitric acid are both carried out in a glass beaker. The high-temperature dissolution with perchloric acid and nitric acid is carried out by heating on a hot plate until white fumes of perchloric acid are emitted. After the white fumes are completely emitted, remove the beaker and cool it. Add 2-5mL of dilute hydrochloric acid (1+1) and 40-60mL of water, and heat to boiling. Step 4: After cooling the acid-dissolved sample, transfer it to a volumetric flask and make up to volume. Filter or clarify the solution and then dilute or concentrate it to obtain the solution to be tested.

2. The sample pretreatment method for high-carbon secondary battery waste testing according to claim 1, characterized in that, In step 1, the crucible is one of a porcelain crucible, an iron crucible, or a high-alumina crucible.

3. The sample pretreatment method for high-carbon secondary battery waste testing according to claim 1, characterized in that, In step 1, the furnace door is opened 2-4 times during the aerobic calcination process.

4. The sample pretreatment method for high-carbon secondary battery waste testing according to claim 1, characterized in that, In step 2, the calcined sample is ground and sieved, specifically including: grinding the calcined sample in a sample preparation machine or grinder for 1-10 minutes, and then sieving it through a 120-200 mesh sieve.

5. The sample pretreatment method for high-carbon secondary battery waste testing according to claim 1, characterized in that, In step 4, the sample dissolved in acid is cooled and then transferred to a volumetric flask and brought to volume. After filtration or clarification, the solution is obtained by full volume or dilution to obtain the test solution. Specifically, the sample dissolved in acid is cooled and then transferred to a 100mL or 200mL volumetric flask and brought to volume. After dry filtration with filter paper or filter membrane, or clarification, the corresponding filtrate or clarified solution is obtained by full volume or dilution according to the element content to obtain the test solution.

6. The sample pretreatment method for high-carbon secondary battery waste testing according to claim 1, characterized in that, The content of lithium, cobalt, manganese, nickel, iron, and copper in the test solution was determined by flame atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry. The mass percentage of the analyte was calculated as Wx = ρ*V*n / m*K, where ρ is the measured concentration of the analyte in mg / L, V is the volume of the final volume in step 4, n is the dilution factor (n = 1 when full volume determination is used), m is the amount of sample weighed in step 3 in g, and K is the mass ratio of the sample before and after calcination in step 1.