This Standard specifies the analysis methods for moisture content, volatile constituent, ash content, fixed carbon content, sulfur content and acid soluble iron content of graphite products.
This Standard applies to natural graphite products.
2 Normative References
The following normative documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments to (excluding corrections to), or revisions of, any of these publications do not apply. However, all parties coming to an agreement according to this standard are encouraged to study whether the latest editions of these documents are applicable. For undated references, the latest editions of the normative documents referred to apply.
GB/T 3518 Flake graphite
GB/T 3519 Amorphous graphite
3 General Requirements
3.1 The chemical analysis samples obtained according to the requirements of GB/T 3518 and GB/T 3519 shall be stored in a plastic bag or a flask with ground mouth, and the sample weight is no less than 50g.
3.2 In addition to moisture content determination, as for other analysis items, the analysis shall be conducted after the sample is baked at 105℃~110℃ to constant weight.
3.3 The accuracy of the weight of high/medium/low carbon sample shall be 0.1 mg; if constant weight is required, it shall be the difference of two times weighing which is no greater than 0.3 mg. The accuracy of the weighing of ultrapure graphite samples shall be 0.02 mg; the constant weight is the difference of two times weighing which is no greater than 0.05 mg.
3.4 Parallel determination must be carried out on all analysis items. Blank test shall be carried out for sulfur analysis.
3.5 The calculated results of ultrapure graphite shall have three digits after the decimal point, and the calculated results of other items shall have two digits after the decimal point.
3.6 Unless otherwise stated, the water used in this method is only approved distilled water, deionized water or water in equivalent purity during the analysis.
3.7 Solution concentration is molar concentration or the mass of solute contained in 1L solution (g/L). (1+1), (1+2), (m+n) refer to the ratio of solute volume to water volume. Unless otherwise stated, the adopted solution is water solution.
3.8 Unless otherwise stated, only approved analytically pure or guaranteed reagent is adopted in the analysis. Only approved reference reagent or spectroscopecally pure/ultrapure reagent is adopted for the calibrated reagent. Unless otherwise stated, as for the adopted acid and ammonia water in the analysis, only approved concentrated acid or concentrated alkali is used.
