ISO 21068-1:2024
Chemical analysis of raw materials and refractory products containing silicon-carbide, silicon-nitride, silicon-oxynitride and sialon — Part 1: General information, terminology and sample preparation
Chemical analysis of raw materials and refractory products containing silicon-carbide, silicon-nitride, silicon-oxynitride and sialon — Part 1: General information, terminology and sample preparation
- Статус документа:
- Действующий
- Формат:
- Электронный (PDF)
- Количество страниц:
- 6
- Дата публикации:
- 3 мая 2024 г.
- Издание:
- ISO IS 21068 edition 2 version 1
- ICS:
- 81.080
This document gives definitions and specifies techniques for the preparation of samples for the chemical analysis of silicon-carbide-containing raw materials and refractory products including: a) SiC raw materials; b) graphite brick containing silicon carbide; c) silicon carbide brick (includes the bricks containing silicon nitride, silicon oxynitride, sialon); d) refractories containing carbon and/or silicon carbide mixed with clay; e) refractories containing carbon and/or silicon carbide mixed with silica (and fused silica); f) refractories containing carbon and/or silicon carbide mixed with high alumina material; g) refractories containing carbon and/or silicon carbide mixed with magnesia (and dolomite); h) refractories containing carbon and/or silicon carbide mixed with chrome mineral or magnesia-chrome materials; i) refractories containing carbon and/or silicon carbide except those described in a) to h) above. The items of analysis described in ISO 21068-2, ISO 21068-3 and ISO 21068-4 are as follows: — loss on drying (LOD); — loss on ignition (LOI); — total carbon, Ctotal; — free carbon, Cfree; — silicon carbide, SiC; — free silicon (Sifree); — free aluminium (Alfree); — free magnesium (Mgfree); — free iron (Fefree); — silicon(IV) dioxide (SiO2); — aluminium(III) oxide (Al2O3); — iron(III) oxide (Fe2O3); — titanium(IV) oxide (TiO2); — calcium oxide (CaO); — magnesium oxide (MgO); — sodium oxide (Na2O); — potassium oxide (K2O); — chromium(III) oxide (Cr2O3); — zirconium(IV) oxide (ZrO2); — boron oxide (total boron calculated as B2O3); — nitrogen; — oxygen; — nitrides (undifferentiated: Si3N4, AlN, BN, sialon, oxy-nitrides, etc.); — mineralogical phases (XRD-methods).
Abstract
Overview
ISO 21068-1:2024 - "Chemical analysis of raw materials and refractory products containing silicon‑carbide, silicon‑nitride, silicon‑oxynitride and sialon - Part 1" defines general information, terminology and sample preparation techniques used in the ISO 21068 series. It is the foundational part of a multipart standard addressing chemical analysis of SiC‑containing raw materials and refractory products (shaped and unshaped). The standard covers sample handling from sampling to pre‑treatment and guidance on preliminary analyses and reporting.
Key topics and requirements
- Scope and material types: Applies to SiC raw materials and a wide range of refractories, including graphite bricks, SiC bricks (including Si‑nitride/oxynitride and sialon), and refractories containing carbon/SiC mixed with clay, silica, high‑alumina, magnesia, chrome/magnesia‑chrome, or other matrices.
- Terminology: Harmonised definitions for key terms such as free carbon, free metallic components (e.g., free Si, Al, Mg), oxide bond components (e.g., SiO2), moisture, and volatile components - supporting consistent lab communication and reporting.
- Sampling and sample preparation: References ISO 5022 (shaped products) and ISO 8656‑1 (unshaped products) for sampling schemes; details on sample pre‑treatment, crushing and thermal pre‑treatment (drying), and avoiding contamination during preparation.
- Preliminary analyses and expression of results: Guidance on preliminary checks, how results should be expressed and documented, and information to be included in the test report.
- Analytical context: Part 1 sets the groundwork for the specific determinations described in ISO 21068‑2, ‑3 and ‑4 (e.g., LOD, LOI, total and free carbon, SiC, free metals, major oxides, nitrogen/oxygen, nitrides, and mineralogical phases by XRD).
Practical applications and users
ISO 21068‑1 is essential for:
- Quality control laboratories performing chemical analysis of refractory raw materials and products.
- Manufacturers of silicon‑carbide refractories, bricks and monolithic refractories ensuring consistent sampling and preparation.
- R&D teams developing SiC‑containing formulations (including sialon and oxynitride systems).
- Third‑party testing bodies and regulatory or procurement authorities requiring standardized, comparable data.
Benefits include improved accuracy and comparability of compositional data (SiC, free carbon, free metals, oxides, nitrides), and clearer reporting for production control, material specification and failure analysis.
Related standards
- ISO 21068‑2 / ISO 21068‑3 / ISO 21068‑4 (analytical methods)
- ISO 5022 (shaped refractory sampling)
- ISO 8656‑1 (unshaped refractory sampling)
- ISO 12677 (XRF fused bead methods)
- ISO 1927‑1, ISO 10081 series (refractory classifications)
Keywords: ISO 21068‑1, silicon carbide, SiC, refractory products, sample preparation, chemical analysis, free carbon, XRD, XRF, ICP‑OES, sialon.
Технические детали
- Технический комитет
- ISO/TC 33 - Refractories
- SKU
- ISO 21068-1:2024
Похожие стандарты
Стандарты, упомянутые в описании
ISO 21068-2:2008
ОтменёнChemical analysis of silicon-carbide-containing raw materials and refractory products — Part 2: Determination…
ISO 5022:1979
ДействующийShaped refractory products — Sampling and acceptance testing
Overview ISO 5022:1979 - "Shaped refractory products - Sampling and acceptance testing" provides standardized directives for sampling shaped refractory products and for obtaining, from the smallest p…
ISO 8656-1:1988
ДействующийRefractory products — Sampling of raw materials and unshaped products — Part 1: Sampling scheme
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