GB/T 3780.25-2018Carbon black—Part 25: Determination of carbon content (English PDF)

Foreword

GB/T 3780 "carbon black" is divided into the following parts.

--- Part 1. Test method for iodine absorption;

--- Part 2. Determination of oil absorption values;

--- Part 4. Determination of the oil absorption value of compressed specimens;

---Part 5. Determination of specific surface area CTAB method;

---Part 6. Determination of color strength;

--- Part 7. Determination of pH;

--- Part 8. Determination of heating loss;

--- Part 10. Determination of ash;

--- Part 12. Inspection of impurities;

--- Part 14. Determination of sulfur content;

---Part 15. Determination of light transmittance of toluene extracts;

--- Part 17. Indirect measurement of particle size reflectance method;

---Part 18. Identification methods in natural rubber (NR);

--- Part 21. Determination of sieve residue water rinse method;

--- Part 22. Calculating process capability index using process control data;

--- Part 23. Sampling and identification of fugitive carbon black or other environmental particles;

--- Part 24. Determination of void volume;

---Part 25. Determination of carbon content;

--- Part 26. Determination of carbon content in carbon black feedstocks.

This part is the 25th part of GB/T 3780.

This part is drafted in accordance with the rules given in GB/T 1.1-2009.

1 Scope

This part of GB/T 3780 specifies the method for determining the total carbon content in carbon black samples by instrument.

This section applies to carbon black with intrinsic carbon content of 95% to 100% after incomplete combustion or thermal cracking.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this document. For undated references, the latest edition (including all amendments) applies to this document.

GB/T 3778 carbon black for rubber

GB/T 7044 pigment carbon black

GB/T 8170 Numerical Rounding Rules and Representation and Determination of Limit Values

HG/T 2725 Bulk Carbon Black Sampling Standard Method

3 Principle

The combustion boat containing the weighed sample is placed in a 1350 ° C tube furnace, the sample is completely burned in a continuous oxygen flow, and the carbon is oxidized.

Carbon dioxide, the gas stream passes through a trap filled with magnesium perchlorate, removes water vapor and particulates, and passes through the detection cell in the exact infrared spectrum.

The carbon dioxide concentration was measured at an infrared (IR) absorption detector at a wavelength.

4 Instruments

4.1 Analytical balance with a graduation value of 0.1 mg.

4.2 Gravity convection oven, the temperature can be maintained (125 ± 5) °C.

5 Reagents and materials

5.1 Magnesium perchlorate, analytically pure.

5.2 High purity oxygen, purity >=99.9%.