GB/T 6900-2025 Chemical analysis of alumino—silicate refractories English, Anglais, Englisch, Inglés, えいご
This is a draft translation for reference among interesting stakeholders. The finalized translation (passing through draft translation, self-check, revision and verification) will be delivered upon being ordered.
ICS 81.080 CCS Q 40
People's Republic of China National Standard
GB/T 6900-2025 Replaces GB/T 6900-2016
Chemical Analysis Methods for Alumino - Silicate Refractories
Issued on August 29, 2025
Implemented on March 1, 2026
Issued by the State Administration for Market Regulation
Standardization Administration of China
Contents
Foreword
1 Scope
2 Normative References
3 Terms and Definitions
4 Instruments and Equipment
5 Sample Preparation
6 General Principles
7 Determination of Loss on Ignition (LOI)
8 Determination of Silicon Dioxide (SiO₂)
9 Determination of Aluminum Oxide (Al₂O₃)
10 Determination of Iron Oxide (Fe₂O₃)
11 Determination of Titanium Dioxide (TiO₂)
12 Determination of Calcium Oxide (CaO)
13 Determination of Magnesium Oxide (MgO)
14 Determination of Potassium Oxide (K₂O) and Sodium Oxide (Na₂O)
15 Determination of Manganese Oxide (MnO) [Flame Atomic Absorption Spectrometry (0.01% ≤ w(MnO) ≤ 0.25%)]
16 Determination of Phosphorus Pentoxide (P₂O₅) [Molybdenum Blue Spectrophotometry (0.05% ≤ w(P₂O₅) ≤ 5%)]
17 Simultaneous Determination of Silicon Dioxide (SiO₂), Iron Oxide (Fe₂O₃), Titanium Dioxide (TiO₂), Calcium Oxide (CaO), Magnesium Oxide (MgO), Potassium Oxide (K₂O), Sodium Oxide (Na₂O), Manganese Oxide (MnO), Phosphorus Pentoxide (P₂O₅), Zirconium Oxide (ZrO₂), Chromium Oxide (Cr₂O₃) [Inductively Coupled Plasma Optical Emission spectrometry (ICP-OES) (w(MxOy) < 15%)]
18 Test Report
Appendix A (Normative) Acceptance Procedure for Analytical Values
Appendix B (Informative) Calibration Curves for Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES)
Chemical Analysis Methods for Alumino-Silicate Refractories
Warning— Personnel using this document shall have practical experience in regular laboratory work and be familiar with the physicochemical properties of strong acids and bases. High-temperature and strong acid/base processes during sample pretreatment are hazardous sources. Operators must master safe operating procedures. This document does not address all potential safety issues; users are responsible for implementing appropriate safety and health measures and ensuring compliance with national regulations.
1 Scope
This document describes chemical analysis methods for the following components in alumino-silicate refractories:
Loss on Ignition (LOI), Silicon Dioxide (SiO₂), Aluminum Oxide (Al₂O₃), Iron Oxide (Fe₂O₃), Titanium Dioxide (TiO₂), Calcium Oxide (CaO), Magnesium Oxide (MgO), Potassium Oxide (K₂O), Sodium Oxide (Na₂O), Manganese Oxide (MnO), Phosphorus Pentoxide (P₂O₅), Zirconium Oxide (ZrO₂), Chromium Oxide (Cr₂O₃)
This document applies to chemical analysis of alumino-silicate refractories, including:
Raw materials: pyrophyllite, bauxite, etc.
Products: clay bricks, high-alumina bricks, semi-silica bricks, mullite bricks, corundum bricks, etc.
Fiber products: alumino-silicate refractory fibers and their products
Unshaped materials: clay-based and high-alumina muds, castables, plastics, etc.
2 Normative References
The following documents contain provisions that, through reference in this text, constitute essential requirements for this document. For dated references, only the edition cited applies; for undated references, the latest edition (including all amendments) applies.
GB/T 4513.2 Unshaped Refractory Materials—Part 2: Sampling
GB/T 4984—2023 Chemical Analysis Methods for Zirconium-containing Refractories
GB/T 7728 General Rules for Chemical Analysis of Metallurgical Products—Flame Atomic Absorption Spectrometry
GB/T 8170 Rules for rounding off numerical values and representation and judgment of limiting values
GB/T 10325 Sampling Inspection Rules for Shaped Refractory Products
GB/T 12805 Laboratory Glassware—Burette
GB/T 12806 Laboratory Glassware—Volumetric Flask
GB/T 12808 Laboratory Glassware—Pipette
GB/T 17617 Sampling Inspection Rules for Refractory Raw Materials
GB/T 18930 Terminology of Refractory Materials
3 Terms and Definitions
Terms and definitions defined in GB/T 18930 apply to this document.
4 Instruments and Equipment
4.1 Balance: readability 0.1 mg.
4.2 Platinum or porcelain crucible: 30 mL.
4.3 Automatic temperature-controlled drying oven: operating temperature 110°C, temperature fluctuation ≤ ±1.5°C.
4.4 High-temperature furnace: maximum operating temperature ≥1,100°C, with automatic temperature control.
4.5 Spectrophotometer.
4.6 Constant-temperature magnetic stirrer.
4.7 G4 glass funnel.
4.8 Pipette: Class A per GB/T 12808.
4.9 Burette: Class A per GB/T 12805.
4.10 Volumetric flask: Class A per GB/T 12806.
4.11 Atomic absorption spectrophotometer: equipped with air-acetylene burner, calcium, magnesium, potassium, sodium, and manganese hollow cathode lamps. Air and acetylene gas purity shall be ≥99.9% to provide a stable, clear lean flame (uniform blue-white band). Minimum precision requirements, characteristic concentration, detection limits, and linearity of calibration curves shall comply with GB/T 7728.
4.12 Flame photometer: capable of measuring potassium and sodium.
4.13 Inductively coupled plasma optical emission spectrometer (ICP-OES): multi-channel simultaneous type, sequential scanning type, or full-spectrum direct-reading type.
5 Sample Preparation
5.1 Sampling
Laboratory samples shall be collected per GB/T 10325, GB/T 17617, or GB/T 4513.2.
5.2 Preparation
5.2.1 Crush the laboratory sample to pass a 6.7 mm standard sieve, then reduce to approximately 100 g via quartering. If the sampling contract specifies otherwise or sample form limitations prevent obtaining ≥100 g, an exception may apply. Further reduce the sample to <0.5 mm, then grind to pass a 90 μm standard sieve.
5.2.2 Dry the sample at 105–110°C for 2 h in a forced-air oven before analysis, and cool to room temperature in a desiccator. For samples prone to hydration, measures shall be taken to prevent hydration.
6 General Principles
6.1 General Provisions
6.1.1 Unless otherwise specified, only reagents confirmed as analytical grade and distilled water, deionized water, or water of equivalent purity shall be used.
6.1.2 "Constant mass" in analysis is defined as ≤0.2 mg difference between two weighings.
6.2 Number of Determinations
Two determinations shall be performed under repeatability conditions.
6.3 Blank Test
A blank test shall be conducted under repeatability conditions.
6.4 Result Expression
6.4.1 Results shall be rounded per GB/T 8170. For content >0.10%, retain two decimal places; for content ≤0.10%, retain two significant figures. If specified in the supply contract, round per contract requirements.
6.4.2 Standard solution calibration results during testing shall retain four significant figures.
GB/T 6900-2025 Chemical analysis of alumino—silicate refractories English, Anglais, Englisch, Inglés, えいご
This is a draft translation for reference among interesting stakeholders. The finalized translation (passing through draft translation, self-check, revision and verification) will be delivered upon being ordered.
ICS 81.080 CCS Q 40
People's Republic of China National Standard
GB/T 6900-2025 Replaces GB/T 6900-2016
Chemical Analysis Methods for Alumino - Silicate Refractories
Issued on August 29, 2025
Implemented on March 1, 2026
Issued by the State Administration for Market Regulation
Standardization Administration of China
Contents
Foreword
1 Scope
2 Normative References
3 Terms and Definitions
4 Instruments and Equipment
5 Sample Preparation
6 General Principles
7 Determination of Loss on Ignition (LOI)
8 Determination of Silicon Dioxide (SiO₂)
9 Determination of Aluminum Oxide (Al₂O₃)
10 Determination of Iron Oxide (Fe₂O₃)
11 Determination of Titanium Dioxide (TiO₂)
12 Determination of Calcium Oxide (CaO)
13 Determination of Magnesium Oxide (MgO)
14 Determination of Potassium Oxide (K₂O) and Sodium Oxide (Na₂O)
15 Determination of Manganese Oxide (MnO) [Flame Atomic Absorption Spectrometry (0.01% ≤ w(MnO) ≤ 0.25%)]
16 Determination of Phosphorus Pentoxide (P₂O₅) [Molybdenum Blue Spectrophotometry (0.05% ≤ w(P₂O₅) ≤ 5%)]
17 Simultaneous Determination of Silicon Dioxide (SiO₂), Iron Oxide (Fe₂O₃), Titanium Dioxide (TiO₂), Calcium Oxide (CaO), Magnesium Oxide (MgO), Potassium Oxide (K₂O), Sodium Oxide (Na₂O), Manganese Oxide (MnO), Phosphorus Pentoxide (P₂O₅), Zirconium Oxide (ZrO₂), Chromium Oxide (Cr₂O₃) [Inductively Coupled Plasma Optical Emission spectrometry (ICP-OES) (w(MxOy) < 15%)]
18 Test Report
Appendix A (Normative) Acceptance Procedure for Analytical Values
Appendix B (Informative) Calibration Curves for Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES)
Chemical Analysis Methods for Alumino-Silicate Refractories
Warning— Personnel using this document shall have practical experience in regular laboratory work and be familiar with the physicochemical properties of strong acids and bases. High-temperature and strong acid/base processes during sample pretreatment are hazardous sources. Operators must master safe operating procedures. This document does not address all potential safety issues; users are responsible for implementing appropriate safety and health measures and ensuring compliance with national regulations.
1 Scope
This document describes chemical analysis methods for the following components in alumino-silicate refractories:
Loss on Ignition (LOI), Silicon Dioxide (SiO₂), Aluminum Oxide (Al₂O₃), Iron Oxide (Fe₂O₃), Titanium Dioxide (TiO₂), Calcium Oxide (CaO), Magnesium Oxide (MgO), Potassium Oxide (K₂O), Sodium Oxide (Na₂O), Manganese Oxide (MnO), Phosphorus Pentoxide (P₂O₅), Zirconium Oxide (ZrO₂), Chromium Oxide (Cr₂O₃)
This document applies to chemical analysis of alumino-silicate refractories, including:
Raw materials: pyrophyllite, bauxite, etc.
Products: clay bricks, high-alumina bricks, semi-silica bricks, mullite bricks, corundum bricks, etc.
Fiber products: alumino-silicate refractory fibers and their products
Unshaped materials: clay-based and high-alumina muds, castables, plastics, etc.
2 Normative References
The following documents contain provisions that, through reference in this text, constitute essential requirements for this document. For dated references, only the edition cited applies; for undated references, the latest edition (including all amendments) applies.
GB/T 4513.2 Unshaped Refractory Materials—Part 2: Sampling
GB/T 4984—2023 Chemical Analysis Methods for Zirconium-containing Refractories
GB/T 7728 General Rules for Chemical Analysis of Metallurgical Products—Flame Atomic Absorption Spectrometry
GB/T 8170 Rules for rounding off numerical values and representation and judgment of limiting values
GB/T 10325 Sampling Inspection Rules for Shaped Refractory Products
GB/T 12805 Laboratory Glassware—Burette
GB/T 12806 Laboratory Glassware—Volumetric Flask
GB/T 12808 Laboratory Glassware—Pipette
GB/T 17617 Sampling Inspection Rules for Refractory Raw Materials
GB/T 18930 Terminology of Refractory Materials
3 Terms and Definitions
Terms and definitions defined in GB/T 18930 apply to this document.
4 Instruments and Equipment
4.1 Balance: readability 0.1 mg.
4.2 Platinum or porcelain crucible: 30 mL.
4.3 Automatic temperature-controlled drying oven: operating temperature 110°C, temperature fluctuation ≤ ±1.5°C.
4.4 High-temperature furnace: maximum operating temperature ≥1,100°C, with automatic temperature control.
4.5 Spectrophotometer.
4.6 Constant-temperature magnetic stirrer.
4.7 G4 glass funnel.
4.8 Pipette: Class A per GB/T 12808.
4.9 Burette: Class A per GB/T 12805.
4.10 Volumetric flask: Class A per GB/T 12806.
4.11 Atomic absorption spectrophotometer: equipped with air-acetylene burner, calcium, magnesium, potassium, sodium, and manganese hollow cathode lamps. Air and acetylene gas purity shall be ≥99.9% to provide a stable, clear lean flame (uniform blue-white band). Minimum precision requirements, characteristic concentration, detection limits, and linearity of calibration curves shall comply with GB/T 7728.
4.12 Flame photometer: capable of measuring potassium and sodium.
4.13 Inductively coupled plasma optical emission spectrometer (ICP-OES): multi-channel simultaneous type, sequential scanning type, or full-spectrum direct-reading type.
5 Sample Preparation
5.1 Sampling
Laboratory samples shall be collected per GB/T 10325, GB/T 17617, or GB/T 4513.2.
5.2 Preparation
5.2.1 Crush the laboratory sample to pass a 6.7 mm standard sieve, then reduce to approximately 100 g via quartering. If the sampling contract specifies otherwise or sample form limitations prevent obtaining ≥100 g, an exception may apply. Further reduce the sample to <0.5 mm, then grind to pass a 90 μm standard sieve.
5.2.2 Dry the sample at 105–110°C for 2 h in a forced-air oven before analysis, and cool to room temperature in a desiccator. For samples prone to hydration, measures shall be taken to prevent hydration.
6 General Principles
6.1 General Provisions
6.1.1 Unless otherwise specified, only reagents confirmed as analytical grade and distilled water, deionized water, or water of equivalent purity shall be used.
6.1.2 "Constant mass" in analysis is defined as ≤0.2 mg difference between two weighings.
6.2 Number of Determinations
Two determinations shall be performed under repeatability conditions.
6.3 Blank Test
A blank test shall be conducted under repeatability conditions.
6.4 Result Expression
6.4.1 Results shall be rounded per GB/T 8170. For content >0.10%, retain two decimal places; for content ≤0.10%, retain two significant figures. If specified in the supply contract, round per contract requirements.
6.4.2 Standard solution calibration results during testing shall retain four significant figures.
