GOST 25699.8-90 PDF

Full title and description

GOST 25699.8-90 — "Carbon black for rubber industry. Method for determination of ash" (Russian: "Углерод технический для производства резины. Метод определения зольности"). The standard specifies a gravimetric method to determine the ash content of technical (industrial) carbon used in rubber production.

Abstract

This standard defines the laboratory procedure for preparing a sample of technical carbon, combusting it in a crucible at high temperature to obtain residual ash, and calculating the ash content as a percentage of the original sample mass. It covers required apparatus, sampling reference, test conditions (temperature and time), and result processing including repeatability limits.

General information

• Status: Active / действующий.
• Publication date: Introduced into force 1 July 1991 (approved 27 July 1990).
• Publisher: Gosstandart / Interstate standardization body (USSR Gosstandart — межгосударственный стандарт).
• ICS / categories: Rubber and rubber products classification (OKC/ICS area — related code 83.040.20).
• Edition / version: Designation suffix "-90" (approved 1990, effective 1991). Replaces earlier version ГОСТ 25699.8-83.
• Number of pages: 3 pages (concise test-method standard).

Scope

The standard applies to technical carbon (carbon black) intended for the rubber industry and specifies the method for determination of ash content by ignition in a crucible at approximately 900–950 °C until complete carbon combustion. It is intended for quality control, acceptance testing and laboratory verification of carbon black batches and materials used in rubber compounds.

Key topics and requirements

• Sampling reference: sampling is performed in accordance with the series sampling standard (GOST 25699.1).
• Apparatus: laboratory balances (GOST 24104), low crucibles (GOST 9147), muffle/electric furnace capable of 900–950 °C, drying oven (≈105 ±2 °C), desiccator.
• Test conditions: dry and weigh sample (≈1.9000–2.1000 g), combust in crucible at 900–950 °C for not less than 4 hours (until complete ashing), cool in desiccator and weigh residues.
• Calculation and reporting: ash content (%) calculated gravimetrically from crucible, sample and residue masses; results reported as the mean of two parallel determinations with specified repeatability and allowable divergences.
• Performance characteristics: prescribed precision limits (e.g., repeatability and inter-laboratory divergence criteria) and rounding rules for reported results.

Typical use and users

Used by chemical and materials testing laboratories, quality control departments of carbon black manufacturers, rubber compounders, research institutes and certification bodies involved in rubber raw-materials testing. Typical applications include incoming inspection of carbon black, batch certification, R&D on rubber fillers, and regulatory compliance testing.

Related standards

This document is part of the GOST 25699 series for technical carbon for rubber (other parts address sampling, other test methods and technical requirements). It references or is used alongside standards such as GOST 25699.1-90 (sampling), GOST 24104 (laboratory balances), GOST 9147 (crucibles) and related ГОСТs cited in the 25699 family and rubbers testing domain.

Keywords

GOST 25699.8-90; carbon black; technical carbon; rubber industry; ash determination; zольность; gravimetric method; laboratory test; sampling; GOST 25699.1.

FAQ

Q: What is this standard?

A: GOST 25699.8-90 is a national standard that specifies the laboratory gravimetric method for determining the ash content of technical carbon (carbon black) used in rubber production.

Q: What does it cover?

A: It covers sample preparation, required apparatus (balances, crucibles, furnace, dryer, desiccator), test procedure (combustion at ~900–950 °C), calculation of ash percentage and requirements for reporting and repeatability.

Q: Who typically uses it?

A: Quality-control laboratories at carbon-black manufacturers, independent testing labs, rubber compounders, and certification or regulatory bodies that test raw materials for the rubber industry.

Q: Is it current or superseded?

A: The standard is listed as active (действует) and the date of introduction into force is 1 July 1991. It replaced an earlier edition (ГОСТ 25699.8-83). Users should verify national/regional adoption or any later amendments before use.

Q: Is it part of a series?

A: Yes — it is one part of the GOST 25699 series addressing technical carbon for rubber, with other parts specifying sampling, additional test methods and technical requirements.

Q: What are the key keywords?

A: Carbon black; technical carbon; ash; ashiness; zольность; rubber industry; gravimetric determination; laboratory method; GOST 25699.8-90.