GB/T 3521-2023 Methods for chemical analysis of graphite
WARNING - Persons using this document shall be familiar with normal laboratory practice. This document does not purport to address all of the safety, health and environmental protection issues related to its use. It is the responsibility of the user to establish appropriate safety and health and environmental protection measures and to ensure compliance with any national regulatory conditions.
1 Scope
This document describes the analytical methods for moisture content, 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 following documents contain requirements which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
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 limit
3 Terms and definitions
No terms and definitions are listed in this document.
4 General requirements
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 glass stoppered bottles with a sample size of not less than 50g.
4.2 Except for moisture content determination, the specimens shall be dried to constant weight at 105°C to 110°C for other analysis items.
4.3 The mass of high, medium and low carbon specimens shall be accurate to 0.1 mg, when constant weight is required, the difference between two consecutive constant-weight weighings shall not be more than 0.3 mg; the mass of high purity graphite specimens shall be accurate to 0.02 mg, when constant weight is required, the difference between two consecutive constant-weight weighings shall not be more than 0.05 mg.
4.4 Each analysis item shall be subjected to at least two parallel determinations. The arithmetic mean of the two parallel determination results shall be taken as the analysis result.
4.5 The calculation result of high purity graphite shall be rounded to 4 decimal places in accordance with GB/T 8170, and the calculation results of all other items shall be rounded to 2 decimal places in accordance with GB/T 8170.
4.6 Unless otherwise specified, the water used in this method shall not be inferior to Grade 3 water specified in GB/T 6682.
4.7 The concentration of solutions is expressed as molar concentration or mass concentration. Other notations such as (1+1), (1+2), and (m+n) refer to the volume ratio of solute to water. Unless otherwise specially specified, all solutions used shall be aqueous solutions.
4.8 Unless otherwise specified, the reagents used in this method shall only be those confirmed as analytical grade or guaranteed reagent. Reagents for calibration shall only be those confirmed as standard reagent, spectroscopically pure or high-purity reagent. The acids and ammonia water used shall only be confirmed concentrated acids or concentrated ammonia water.
5 Determination of moisture content
5.1 Instruments, apparatus and materials
5.1.1 Electrically heated drying oven: from room temperature to 200 ℃, with a temperature control accuracy of ±2 ℃.
5.1.2 Analytical balance: with an accuracy not less than 0.1 mg.
5.1.3 Weighing bottle with ground stopper: 20 mL.
5.2 Analytical procedures
Accurately weigh 2 g to 5 g of undried specimen, accurate to 0.1 mg, recorded as m₀. Place it in the weighing bottle with ground stopper that has been dried to constant weight, slightly open the bottle cap, and put it in the oven at 105 ℃ to 110 ℃ for 2 h. Then take out the weighing bottle with ground stopper, close the cap tightly, place it in a desiccator to cool for 30 min, and weigh it, recorded as m. Repeat this operation until constant weight is achieved.
Contents
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 General requirements
5 Determination of moisture content
6 Determination of volatile matter
7 Determination of ash content
8 Determination of fixed carbon content
9 Determination of sulfur content
10 Determination of acid-soluble iron
11 Determination of iron content
GB/T 3521-2023 Methods for chemical analysis of graphite
WARNING - Persons using this document shall be familiar with normal laboratory practice. This document does not purport to address all of the safety, health and environmental protection issues related to its use. It is the responsibility of the user to establish appropriate safety and health and environmental protection measures and to ensure compliance with any national regulatory conditions.
1 Scope
This document describes the analytical methods for moisture content, 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 following documents contain requirements which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
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 limit
3 Terms and definitions
No terms and definitions are listed in this document.
4 General requirements
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 glass stoppered bottles with a sample size of not less than 50g.
4.2 Except for moisture content determination, the specimens shall be dried to constant weight at 105°C to 110°C for other analysis items.
4.3 The mass of high, medium and low carbon specimens shall be accurate to 0.1 mg, when constant weight is required, the difference between two consecutive constant-weight weighings shall not be more than 0.3 mg; the mass of high purity graphite specimens shall be accurate to 0.02 mg, when constant weight is required, the difference between two consecutive constant-weight weighings shall not be more than 0.05 mg.
4.4 Each analysis item shall be subjected to at least two parallel determinations. The arithmetic mean of the two parallel determination results shall be taken as the analysis result.
4.5 The calculation result of high purity graphite shall be rounded to 4 decimal places in accordance with GB/T 8170, and the calculation results of all other items shall be rounded to 2 decimal places in accordance with GB/T 8170.
4.6 Unless otherwise specified, the water used in this method shall not be inferior to Grade 3 water specified in GB/T 6682.
4.7 The concentration of solutions is expressed as molar concentration or mass concentration. Other notations such as (1+1), (1+2), and (m+n) refer to the volume ratio of solute to water. Unless otherwise specially specified, all solutions used shall be aqueous solutions.
4.8 Unless otherwise specified, the reagents used in this method shall only be those confirmed as analytical grade or guaranteed reagent. Reagents for calibration shall only be those confirmed as standard reagent, spectroscopically pure or high-purity reagent. The acids and ammonia water used shall only be confirmed concentrated acids or concentrated ammonia water.
5 Determination of moisture content
5.1 Instruments, apparatus and materials
5.1.1 Electrically heated drying oven: from room temperature to 200 ℃, with a temperature control accuracy of ±2 ℃.
5.1.2 Analytical balance: with an accuracy not less than 0.1 mg.
5.1.3 Weighing bottle with ground stopper: 20 mL.
5.2 Analytical procedures
Accurately weigh 2 g to 5 g of undried specimen, accurate to 0.1 mg, recorded as m₀. Place it in the weighing bottle with ground stopper that has been dried to constant weight, slightly open the bottle cap, and put it in the oven at 105 ℃ to 110 ℃ for 2 h. Then take out the weighing bottle with ground stopper, close the cap tightly, place it in a desiccator to cool for 30 min, and weigh it, recorded as m. Repeat this operation until constant weight is achieved.
Contents of GB/T 3521-2023
Contents
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 General requirements
5 Determination of moisture content
6 Determination of volatile matter
7 Determination of ash content
8 Determination of fixed carbon content
9 Determination of sulfur content
10 Determination of acid-soluble iron
11 Determination of iron content
