GB/T 3521-2023 PDF English
US$380.00 · In stock · Download in 9 secondsGB/T 3521-2023: Methods for chemical analysis of graphite Delivery: 9 seconds. True-PDF full-copy in English & invoice will be downloaded + auto-delivered via email. See step-by-step procedureStatus: Valid GB/T 3521: Evolution and historical versions
| Standard ID | Contents [version] | USD | STEP2 | [PDF] delivery | Name of Chinese Standard | Status |
| GB/T 3521-2023 | English | 380 |
Add to Cart
|
0-9 seconds. Auto-delivery
|
Methods for chemical analysis of graphite
| Valid |
| GB/T 3521-2008 | English | 125 |
Add to Cart
|
0-9 seconds. Auto-delivery
|
Method for chemical analysis of graphite
| Obsolete |
| GB/T 3521-1995 | English | 399 |
Add to Cart
|
3 days
|
Method for chemical analysis of graphite
| Obsolete |
| GB 3521-1983 | English | 279 |
Add to Cart
|
3 days
|
Method for chemical analysis of graphite
| Obsolete |
Excerpted PDFs (Download full copy in 9 seconds upon purchase)PDF Preview: GB/T 3521-2023
GB/T 3521-2023: Methods for chemical analysis of graphite---This is an excerpt. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.), auto-downloaded/delivered in 9 seconds, can be purchased online: https://www.ChineseStandard.net/PDF.aspx/GBT3521-2023
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 73.080
CCS Q 51
Replacing GB/T 3521-2008
Methods for Chemical Analysis of Graphite
Issued on. DECEMBER 28, 2023
Implemented on. JULY 1, 2024
Issued by. State Administration for Market Regulation;
Standardization Administration of the People’s Republic of China.
Table of Contents
Foreword... 3
1 Scope... 5
2 Normative References... 5
3 Terms and Definitions... 5
4 General Stipulations... 5
5 Determination of Moisture... 6
6 Determination of Volatile Matter... 7
7 Determination of Ash Content... 10
8 Determination of Fixed Carbon Content... 11
9 Determination of Sulfur Content... 14
10 Determination of Acid-soluble Iron... 21
11 Determination of Iron Content... 26
1 Scope
This document describes methods for the analysis of moisture, volatile matter, ash content,
fixed carbon content, sulfur content, acid-soluble iron content and iron content of graphite
products.
This document is applicable to the chemical analysis of natural graphite products.
2 Normative References
The contents of the following documents constitute indispensable clauses of this document
through the normative references in the text. In terms of references with a specified date, only
versions with a specified date are applicable to this document. In terms of references without a
specified date, the latest version (including all the modifications) is applicable to this document.
GB/T 6679 General Rules for Sampling Solid Chemical Products
GB/T 6682 Water for Analytical Laboratory Use - Specification and Test Methods
GB/T 8170 Rules of Rounding off for Numerical Values & Expression and Judgement of
Limiting Values
3 Terms and Definitions
This document does not have terms or definitions that need to be defined.
4 General Stipulations
4.1 Samples for chemical analysis obtained in accordance with the sampling method specified
in GB/T 6679 shall be packed in plastic bags or ground-mouth bottles, and the sampling size
shall be no less than 50 g.
4.2 Except for moisture determination, all other analysis items shall be analyzed after the
specimens are baked to a constant weight at 105 C ~ 110 C.
4.3 The weighing of high, medium and low carbon specimens shall be accurate to 0.1 mg, and
when constant weight is required, the difference between the two weighing values shall not be
greater than 0.3 mg. The weighing of high-purity graphite specimens shall be accurate to 0.02
mg, and when constant weight is required, the difference between the two weighing values shall
not be greater than 0.05 mg.
4.4 Each analysis item shall be determined at least twice in parallel. Take the arithmetic mean
of two parallel determination results as the analysis result.
4.5 The calculation results of high-purity graphite are rounded to four decimal places in
accordance with GB/T 8170, and the calculation results of other items are rounded to two
decimal places in accordance with GB/T 8170.
4.6 Unless otherwise stated, the water used in this Method shall not be lower than Grade-3
water specified in GB/T 6682.
4.7 The concentration of a solution is expressed as molar concentration or mass concentration.
Others, such as. (1 + 1), (1 + 2) and (m + n), etc. refer to the ratio of solute volume to water
volume. Unless otherwise specified, the solutions used are all aqueous solutions.
4.8 Unless otherwise stated, the reagents used in this Method are only those confirmed to be of
analytical purity or guaranteed purity; the reagents used for calibration are only those confirmed
to be primary reagents or of spectral purity or high purity; the acid and ammonia water used are
only confirmed concentrated acid or concentrated ammonia water.
5 Determination of Moisture
5.1 Instruments, Equipment and Materials
5.1.2 Analytical balance. with an accuracy not lower than 0.1 mg.
5.1.3 Ground-mouth weighing bottle. 20 mL.
5.2 Analytical Procedures
5.3 Result Calculation
The mass fraction (w1) of moisture is calculated in accordance with Formula (1).
5.4 Allowable Deviation
The absolute difference between the results of two parallel determinations shall not be greater than 0.05%.
6 Determination of Volatile Matter
6.1 Box-type High-temperature Furnace Method
6.1.1 Method summary
When the specimen is burned at a high temperature, the amount of volatile substance
decomposed and escaped is the volatile matter.
6.1.2 Instruments, Equipment and Materials
6.1.3 Analytical procedures
Accurately weigh-take 1 g of specimen, accurate to 0.1 mg, and record it as m2.Evenly lay it
on the bottom of the double-covered porcelain crucible with a constant weight. Place the
crucible on the crucible holder, put on the double cover, and place it in the box-type high-
temperature furnace (constant-temperature zone).
6.1.4 Result calculation
The mass fraction (w2) of volatile matter is calculated in accordance with Formula (2).
6.1.5 Allowable deviation
The allowable deviation of the results of two parallel determinations is shown in Table 1.
6.2 Nitrogen Protection Method
6.2.1 Method summary
When the specimen is placed in a nitrogen flow and burned at a high temperature, the amount
of volatile substance decomposed and escaped is the volatile matter.
6.2.2 Instruments, Equipment and Materials
6.2.2.1 Analytical balance. with an accuracy not lower than 0.1 mg.
Mass Fraction of Volatile Matter Allowable Deviation
6.2.2.4 Quartz boat. the sample loading volume is not less than 1 g.
6.2.2.5 Nitogen. high-purity nitrogen (mass fraction. 99.995%) can be used directly; pure
nitrogen (mass fraction. 99.9%) needs to be purified before use.
6.2.4 Result calculation
The mass fraction (w3) of volatile matter is calculated in accordance with Formula (3).
6.2.5 Allowable deviation
The allowable deviation of the results of two parallel determinations is shown in Table 2.
7 Determination of Ash Content
7.1 Method Summary
When the specimen is burned at a high temperature, the residue obtained after the graphite
oxidation products and volatiles completely escape is ash content.
7.2 Instruments, Equipment and Materials
7.2.1 Analytical balance. with an accuracy not lower than 0.1 mg.
7.2.4 Desiccator. equipped with color-changing silica gel.
Mass Fraction of Volatile Matter Allowable Deviation
7.3 Analytical Procedures
In accordance with the fixed carbon content, accurately weigh-take 1 g ~ 100 g of dried
specimen (accurate to 0.1 mg) and record it as m8.Place it in a porcelain ark with a constant
weight, put the porcelain ark into the box-type high-temperature furnace.
7.4 Result Calculation
The mass fraction (w4) of ash content is calculated in accordance with Formula (4).
7.5 Allowable Deviation
The allowable deviation of the results of two parallel determinations is shown in Table 3.
8 Determination of Fixed Carbon Content
8.1 Indirect Carbon Determination Method
8.1.1 Method summary
The indirect carbon determination method is also called the combustion method, that is, after
measuring the volatile matter and ash content of the specimen, they are subtracted from the total
Allowable Deviation Mass Fraction of Ash Content
amount, and the difference is the fixed carbon content. This Method is applicable to graphite
products with carbon content (mass fraction) greater than 50%.
8.1.2 Result calculation
8.1.2.1 The fixed carbon content (w5) of high, medium and low carbon graphite is calculated in
accordance with Formula (5).
8.1.2.2 The fixed carbon content (w6) of high-purity graphite is calculated in accordance with
Formula (6).
8.2 Direct Carbon Determination Method
8.2.2 Reagents
8.2.2.1 Hydrochloric acid solution (1 + 1).
8.2.2.2 Iron filing flux. the carbon content (mass fraction) is less than 0.0005%, and the sulfur
content (mass fraction) is less than 0.0005%.
8.2.2.3 Tungsten particle flux. the carbon content (mass fraction) is less than 0.0008%, the
sulfur content (mass fraction) is less than 0.0005%, and the particle size is 0.35 mm ~ 0.83 mm.
8.2.2.4 Graphite standard sample. graphite mineral composition analysis standard substance,
GBW 03118, GBW 03119, GBW 03120.
8.2.2.5 Oxygen. with a purity not less than 99.5%.
8.2.3 Instruments, equipment and materials
8.2.3.1 High-frequency infrared carbon and sulfur analyzer. carbon determination accuracy is
not less than 0.0001%.
8.2.3.2 Analytical balance. with an accuracy not lower than 0.1 mg.
8.2.3.6 Desiccator. equipped with color-changing silica gel.
8.2.3.7 Porcelain crucible.
8.2.6 Analytical procedures
8.2.6.1 Calibration test
Actuate the instrument and pre-heat for 30 minutes. Adjust the instrument to determine the fixed
carbon state. Turn on the oxygen; in accordance with the sample to be determined, select the
standard substance and perform system calibration, until the repeatability of the determination
results reaches the uncertainty range required by the graphite standard sample. Thus, the system
calibration test is completed.
8.2.6.2 Sample test
Add 0.5 g of iron filings flux and 1.5 g of tungsten particle flux into the crucible containing the
treated specimen. Place the crucible on the quartz holder, number it, and click the “ANALYZE”
button to start sample determination. The analysis time is adjusted in accordance with the CO2
release curve provided by the high-frequency infrared carbon and sulfur analyzer system. After
the test is completed, in accordance with the data provided by the instrument, record the
determination results.
8.2.7 Allowable deviation
The allowable deviation of the results of two parallel determinations is shown in Table 4.
9 Determination of Sulfur Content
9.1 Potassium Iodate Titration Method
9.1.2 Reagents
9.1.2.1 Hydrochloric acid solution (3 + 197).
9.1.2.2 Potassium iodate (KIO3). primary reagent.
9.1.2.3 Potassium iodide (KI). analytically pure.
Allowable Deviation Fixed Carbon Content (mass fraction)
9.1.2.4 Soluble starch. analytically pure.
9.1.2.5 Potassium iodate standard solution (0.0888 g/L). accurately weigh-take 0.0888 g of
potassium iodate (KIO3) primary reagent and dissolve it in water. Transfer it to a 1,000 mL
volumetric flask, dilute to the scale and store it in a brown bottle. 1 mL of this solution is
equivalent to containing 0.04 mg of sulfur.
9.1.2.6 Starch-potassium iodide solution. weigh-take 2 g of soluble starch into 50 mL of water
and make it into a paste. While stirring, add the paste to 150 mL of boiling water, boil it for 2
minutes. After cooling, add 6 g of potassium iodide (KI) and stir to dissolve it.
9.1.2.7 Sulfur standard sample. national standard substance of coke or coke whose sulfur
content is determined using the Eschka method.
9.1.3 Instruments, equipment and materials
9.1.3.1 Analytical balance. with an accuracy not lower than 0.1 mg.
9.1.3.3 Sulfur determination device. see Figure 2.
9.1.3.4 Porcelain boat. the sample loading volume is not less than 1 g.
9.1.4 Analytical procedures
9.1.4.2 Specimen determination. add 2/3 volume of hydrochloric acid solution (3 + 197) into
the sulfur determination cup, add 10 mL of starch-potassium iodide solution, and dropwise add
potassium iodate standard solution to make the solution in the sulfur determination cup turn
light blue. Use the same method to prepare a reference solution for judging the end point.
Ventilate for 4 minutes ~ 5 minutes.
9.1.4.3 Determination of correction coefficient. in accordance with the sample content, select a
coke standard sample with an appropriate sulfur content; accurately weigh-take 0.1 g ~ 1.0 g of
standard sample, accurate to 0.1 mg, and record it as m11.In the burned porcelain boat, follow
the subsequent steps in 9.1.4.2.
9.1.5 Result calculation
9.1.5.1 The correction coefficient (F) is calculated in accordance with Formula (7).
9.1.5.2 The sulfur content (w7) is calculated in accordance with Formula (8).
9.1.6 Allowable deviation
The allowable deviation of the results of two parallel determinations is shown in Table 5.
9.2 Combustion Titration Coulometry
9.2.1 Method summary
The specimen is burned and decomposed in the air flow under the action of a catalyst. The
sulfur in the specimen generates sulfur oxides and is absorbed by the potassium iodide solution.
The iodine generated by electrolysis of potassium iodide solution is used for oxidative titration.
In accordance with the electricity consumed by electrolysis to generate iodine, calculate the
total sulfur content in the specimen.
9.2.2 Reagents
Allowable Deviation Sulfur Content (mass fraction)
9.2.2.1 Graphite standard sample. graphite mineral composition analysis standard substance,
GBW 03118, GBW 03119, GBW 03120.
9.2.2.2 Tungsten trioxide. analytically pure.
9.2.2.3 Sodium hydroxide. analytically pure.
9.2.2.4 Potassium iodide. analytically pure.
9.2.3 Instruments, equipment and materials
9.2.3.1 Analytical balance. with an accuracy not lower than 0.1 mg.
9.2.3.2 Coal sample. with a particle size less than 0.3 mm, not less than 100 mg.
9.2.3.3 Color-changing silica gel.
9.2.3.4 Porcelain boat. bisque or corundum product; the length of the sample-holding part is
about 60 mm, and the temperature resistance is greater than 1,200 C.
9.2.3.5 Coulomb sulfur meter. it mainly consists of the following parts.
a) Tubular high-temperature furnace. it can be heated to above 1,200 C and has a high-
9.2.4 Analytical procedures
9.2.4.2 Add 300 mL of electrolyte to the electrolytic cell and turn on the magnetic stirrer.
9.2.4.3 Turn on the electromagnetic pump, adjust the air flow to 1,000 mL/min, and check the air tightness.
9.2.5 Result calculation
The sulfur content (w8) in the specimen is calculated in accordance with Formula (9).
9.2.6 Allowable deviation
The allowable deviation of the results of two parallel determinations is shown in Table 6.
9.3 Infrared Absorption Spectrometry
9.3.1 Method summary
Place the specimen in a resistance furnace, under oxygen flow, burn it at a high temperature.
The sulfur is oxidized into sulfur dioxide gas. Utilize an infrared analyzer and an integration
program to determine the total amount of sulfur dioxide generated. The instrument
automatically calculates the sulfur content in the graphite.
9.3.2 Instruments, equipment and materials
9.3.2.3 Oxygen. with a purity of 99.5%.
9.3.2.4 Porcelain boat. the sample loading volume is not less than 1 g.
9.3.3 Analytical procedures
9.3.3.2 Blank test. place the empty porcelain boat in the center of the combustion furnace for
testing. The test blank value shall not exceed 0.005%.
Allowable Deviation Sulfur Content (mass fraction)
......
Source: Above contents are excerpted from the full-copy PDF -- translated/reviewed by: www.ChineseStandard.net / Wayne Zheng et al.
Tips & Frequently Asked QuestionsQuestion 1: How long will the true-PDF of English version of GB/T 3521-2023 be delivered?Answer: The full copy PDF of English version of GB/T 3521-2023 can be downloaded in 9 seconds, and it will also be emailed to you in 9 seconds (double mechanisms to ensure the delivery reliably), with PDF-invoice. Question 2: Can I share the purchased PDF of GB/T 3521-2023_English with my colleagues?Answer: Yes. The purchased PDF of GB/T 3521-2023_English will be deemed to be sold to your employer/organization who actually paid for it, including your colleagues and your employer's intranet. Question 3: Does the price include tax/VAT?Answer: Yes. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countriesQuestion 4: Do you accept my currency other than USD?Answer: Yes. www.ChineseStandard.us -- GB/T 3521-2023 -- Click this link and select your country/currency to pay, the exact amount in your currency will be printed on the invoice. Full PDF will also be downloaded/emailed in 9 seconds. Question 5: Should I purchase the latest version GB/T 3521-2023?Answer: Yes. Unless special scenarios such as technical constraints or academic study, you should always prioritize to purchase the latest version GB/T 3521-2023 even if the enforcement date is in future. Complying with the latest version means that, by default, it also complies with all the earlier versions, technically. How to buy and download a true PDF of English version of GB/T 3521-2023?A step-by-step guide to download PDF of GB/T 3521-2023_EnglishStep 1: Visit website https://www.ChineseStandard.net (Pay in USD), or https://www.ChineseStandard.us (Pay in any currencies such as Euro, KRW, JPY, AUD).
Step 2: Search keyword "GB/T 3521-2023".
Step 3: Click "Add to Cart". If multiple PDFs are required, repeat steps 2 and 3 to add up to 12 PDFs to cart.
Step 4: Select payment option (Via payment agents Stripe or PayPal).
Step 5: Customize Tax Invoice -- Fill up your email etc.
Step 6: Click "Checkout".
Step 7: Make payment by credit card, PayPal, Google Pay etc. After the payment is completed and in 9 seconds, you will receive 2 emails attached with the purchased PDFs and PDF-invoice, respectively.
Step 8: Optional -- Go to download PDF.
Step 9: Optional -- Click Open/Download PDF to download PDFs and invoice.
See screenshots for above steps: Steps 1~3 Steps 4~6 Step 7 Step 8 Step 9
|