GB/T 2994-2021
High alumina refractory mortars (English Version)
- Standard No.
- GB/T 2994-2021
- Language
- Chinese, Available in English version
- Release Date
- 2021
- Published By
- General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China
- Latest
- GB/T 2994-2021
- Replace
- GB/T 2994-2008
- Scope
- This document specifies the terms and definitions, classification and designation, technical requirements, test methods, quality assessment procedures, packaging, marking, transportation, storage and quality certificates of high alumina refractory mud. This document is applicable to the refractory mud with alumina content greater than or equal to 50% for masonry high-alumina refractory roadways and corundum bricks.
- Introduction
Core changes in the standard revision
Technical dimension 2008 edition 2021 edition Impact of changes Grade system LN-55/LN-65/LN-75 LN-50/LN-60/LN-70 More reasonable alumina content gradient Phosphate grade LN-65P/LN-75P LN-70P Simplified classification system New grades - GN-70P Expanded corundum application scenarios
Analysis of key technical indicators
Refractory requirements: GN-90P reaches 1800°C, 40°C higher than the ordinary type, reflecting the superior high temperature resistance of corundum materials.
Refractoriness under load: Phosphate-bound type (LN-70P) is 150°C higher than the ordinary type, reaching 1550°C under 0.2MPa load.
Key points of the test method
6.6 Load softening temperature test
Specimen preparation needs to be strictly controlled:
- Dimension tolerance±1mm
- Molding pressure980N/cm2
- 65°C step drying process
6.7 Heating permanent line change
Dual consistency control method is adopted:
- Cone penetration method (100-110)×0.1mm
- Jumping table method 10-20% expansion
Engineering application suggestions
Selection principles:
- For working temperature <1400°C, select LN series
- For working conditions with frequent thermal shock, select GN-80P
- Phosphate-bound type is prohibited in acidic environment
Construction control: Bonding time is within the range of 60-180 seconds. In high temperature environment, retarders need to be used for adjustment.
Analysis of Standard Evolution
Since its first release in 1982, this revision reflects three major technological advances:
- Material refinement: Alumina content classification adjusted from 55/65/75 to 50/60/70
- Detection standardization: X-ray fluorescence spectrometry (GB/T21114) added as an option for Al?O? content detection
- Application specialization: Distinguishing between ordinary and phosphate-bound technical routes
GB/T 2994-2021 Referenced Document
- GB/T 15545 General rules for packing, marking, transport, storage and quality certificates of unshaped refractory
- GB/T 21114 Refractories—Chemical analysis by X-ray fluorescence(XRF)—Fused cast-bead method
- GB/T 22459.1 Refractory mortars—Part 1：Determination of consistency using the penetrating cone method*， 2022-03-09 Update
- GB/T 22459.2 Refractory mortars—Part 2：Determination of consistency using the reciprocating flow table method*， 2022-03-09 Update
- GB/T 22459.3 Refractory mortars—Part 3: Determination of joint stability*， 2021-10-11 Update
- GB/T 22459.4 Refractory mortars—Part 4: Determination of flexural bonding strength*， 2022-03-09 Update
- GB/T 22459.5 Refractory mortars—Part 5: Determination of grain size distribution ( sieve analysis )*， 2022-03-09 Update
- GB/T 22459.7 Refractory mortars—Part 7: Determination of other properties
- GB/T 4513.2 Monolithic (unshaped) refractory products—Part 2：Sampling for testing
- GB/T 5988 Refractory products—Determination of permanent change in dimensions on heating*， 2022-03-09 Update
- GB/T 6900 Chemical analysis of alumina silica refractories
- YB/T 370 Refractoies.Determination of refractoriness under load (non-differential, with rising temperature)
GB/T 2994-2021 history
- 2021 GB/T 2994-2021 High alumina refractory mortars
- 2008 GB/T 2994-2008 High alumina refractory mortars
- 1994 GB/T 2994-1994 High alumina refractory mortars