Magnesite, magnesia-alumina, and magnesia-chrome refractory slurry

1 Scope

This standard specifies the classification of magnesite, magnesia-alumina, and magnesia-chrome refractory slurry , Classification of magnesia-chrome refractory slurry , Technical requirements, test methods, quality evaluation procedures, packaging, marking, transportation, storage, and quality certificates.

This standard is applicable to magnesite, magnesia-alumina, and magnesia-chrome refractory slurry used for laying magnesia bricks, magnesia-alumina bricks, and magnesia-chrome bricks.

2 Normative references

The following documents are indispensable for the application of this document. For dated reference documents, , only the specified version applies to this document. For undated reference documents, , the latest version ( including all amendments ) applies to this document.

GB/T 5069 Chemical analysis methods for magnesia-alumina refractories

GB/T 5070 Chemical analysis methods for chrome-containing refractories

GB/T 15545 Packaging, marking, transportation and storage of monolithic refractories

GB/T 17617 Refractory raw materials and monolithic refractories   Sampling

GB/T 21114 Refractory materials X X-ray fluorescence spectrometry chemical analysis method for cast glass chips

GB/T 22459.3   Refractory slurry   Part 3 Part : Bonding time test method

GB/T 22459.4 Refractory slurry Part 4 Part : Room temperature flexural bond strength test method

GB/T 22459.5 Refractory slurry Part 5 Part : Particle size distribution ( Analysis ) Test method

GB/T 22459.7 Refractory slurry   Part 7 Part : High temperature performance test method

3 Classification

Magnesite refractory slurry is classified according to MgO content is divided into :MN-91 、MN-95、MN-97 three grades ; Magnesia-alumina refractory slurry is classified according to MgO content is divided into :MLN-70, MLN-80 two grades ; Magnesia-chrome refractory slurry is classified according to Cr ₂ O ₃, content is divided into :MGN-8 、MGN-12、 MGN-16, MGN-20 four grades.

L 、 G 、 N represent the initials of magnesia, alumina, chrome, and slurry in Chinese Pinyin respectively , The numbers following represent MgO, Cr ₂ O ₃ mass fraction.

4 Technical Requirements

The physicochemical indicators of magnesia, magnesia-alumina, and magnesia-chrome refractory slurries shall conform to the provisions of Tables 1, 2, and 3 respectively, with the chemical composition based on the ignited basis.

5 Test methods

5.1 Chemical analysis shall be carried out according to GB/T 21114 for the sample after calcination, or according to GB/T 5069 for magnesia and magnesia-alumina, or according to GB/T 5070 for magnesia-chromium.

5.2 The test of room temperature flexural bond strength shall be carried out according to GB/T 22459.4.

5.3 The test of heating permanent linear change rate shall be carried out according to GB/T 22459.7,

5.4 The test of bonding time shall be carried out according to GB/T 22459.3.

5.5 The test of particle size distribution (sieve analysis) shall be carried out according to GB/T 22459.5.

6 Quality assessment procedures

6.1 Batching

6.1.1 Products shall be batched according to the same grade number in continuous normal production. A new batch shall be made if the raw materials or production process changes.

6.1.2 The maximum batch size of the same grade of product shall not exceed 60t.

6.2 Sampling

Product sampling shall be carried out according to the provisions of GB/T 17617.

6.3 Judgment rules

Chemical composition, room temperature flexural bond strength, and heating permanent linear change rate are the acceptance inspection items. If the test results all meet the specified values in Table 1, Table 2, and Table 3, the batch of products is qualified.

If there are unqualified items in the test results, samples shall be re-sampled and tested according to 6.2. If the test results meet the provisions of Table 1, Table 2, and Table 3, the batch of products shall be judged as qualified; otherwise, it shall be judged as unqualified.

6.4 Qualified assessment form

Qualified assessment can be carried out in the form of supplier's declaration, user's confirmation, or third-party certification.

7 Packaging, marking, transportation, storage and quality certificate

7.1 Packaging, marking, transportation and storage shall comply with the provisions of GB/T 15545. 7.2 Liquid binders can be packaged and shipped separately.

When the products are shipped, the supplier shall provide a quality certificate and product instruction manual. The quality certificate shall indicate the supplier's name, the demander's name, the production date, the contract number, the standard number, the product name, the grade number, the batch number, the physico-chemical indicators, and the shelf life.

Magnesia, magnesia aluminum, magnesia chrome refractory mud

1 Range

This standard specifies the classification, technical requirements, test methods, quality assessment procedures, packaging, marking, transportation, storage and quality certificate of magnesia, magnesia aluminum, magnesia chrome refractory mud.

This standard is applicable to magnesia, magnesia, magnesia, magnesia, magnesia refractory mud used in laying magnesia brick, magnesia aluminum brick, magnesia chrome brick, etc.

2 Normative reference documents

The following documents are essential for the application of this document. For dated references, only the dated version applies to this document. For undated references, the latest version (including all amendment orders) applies to this document.

GB/T 5069 Method for chemical analysis of Mg-Al refractories

GB/T 5070 Chromium containing refractory chemical analysis method

GB/T 15545 Amorphous refractory packaging, marking, transportation and storage

GB/T 17617 Sampling of refractory raw materials and amorphous refractories

GB/T 21114 Refractories by X-ray fluorescence spectrochemical analysis of fused cast glass sheets

GB/T 22459.3 Refractory mud – Part 3: Test method for bonding time

GB/T 22459.4 Refractory mud – Part 4: Test method for bending and bonding strength at room temperature

GB/T 22459.5 Refractory mud – Part 5: Test method for particle size distribution (analysis)

GB/T 22459.7 Refractory mud – Part 7: Test method for high temperature performance

3 Categories

Magnesium refractory mud is divided into MN-91, MN-95, MN-97 three grades according to MgO content; Mg-aluminum refractory mud is divided into MLN-70, MLN-80 two grades according to MgO content; Magnesium chrome refractory mud is divided into MG-8, MG-12, MG-16, MG-20 four grades according to Cr2O3 content.

M, L, G, and N respectively represent the initial letters of the Chinese pinyin of magnesium, aluminum, chromium, and mud, and the following numbers represent the mass fraction of MgO and Cr2O3 respectively.

4 Technical Requirements

The physical and chemical indexes of magnesia, magnesia aluminum and magnesia chromium refractory mud should conform to the provisions of Table 1, Table 2 and Table 3 respectively, and the chemical composition is based on the burning.

5 Test methods

5.1 Chemical analysis shall be carried out according to GB/T 21114 or GB/T 5069 for magnesium, Mg-aluminum, and GB/T 5070 for magnesium chromium after burning.

5.2 The bending and bonding strength at room temperature shall be tested according to GB/T 22459.4.

5.3 The test of the change rate of the heating permanent line shall be carried out according to GB/T 22459.7.

5.4 The bonding time is tested according to GB/T 22459.3.

5.5 Particle size distribution (sieve analysis) was tested according to GB/T 22459.5.

6 Quality assessment procedures

6.1 Batch Groups

6.1.1 The products shall be batch according to the same grade of continuous normal production. In case of changes in raw materials or production processes, separate batches should be made.

6.1.2 The maximum quantity of the same brand product shall not exceed 60t.

6.2 Sampling

Sampling of products is carried out according to GB/T 17617.

6.3 Decision Rules

Chemical composition, bending and bonding strength at room temperature, and change rate of heating permanent line are the acceptance inspection items. When the test results meet the specified values in Table 1, Table 2 and Table 3, the batch of products is qualified.

If there is any unqualified item in the test result, the sample shall be taken again for testing in accordance with the provisions of 6.2. The inspection results meet the requirements of Table 1, Table 2 and Table 3, and the batch of products are judged to be qualified; Otherwise, it is disqualified.

6.4 Form of conformity assessment

The conformity assessment can be made in the form of the supplier’s declaration, the user’s certification or the third party’s certification.

7 Packing, marking, transportation, storage and quality certificate

7.1 Packaging, marking, transportation and storage shall comply with the provisions of GB/T 15545.

7.2 Liquid binders can be packaged and shipped separately.

7.3 When the products are issued, the supplier shall provide the quality certificate and the product instruction manual. The quality certificate shall contain the name of the supplier, the name of the demander, the production date, the contract number, the standard number, the product name, the brand number, the batch number, the physical and chemical index and the storage period.