1 Scope
This document specifies the classification and nomenclature of alkaline dense and shaped refractory products with a carbon content (mass fraction) of less than 7%. This document applies to alkaline dense and shaped refractory products with a carbon content (mass fraction) of less than 7%.
Note. All products can be covered with metal sheets and all non-fired products can be reinforced with metal sheets and/or metal fibres.
2 Normative references
The contents of the following documents constitute essential provisions of this document by means of normative references in the text, where, for dated references, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendment sheets) applies to this document.
3 Terms and definitions
The terms and definitions defined in GB/T 18930 apply to this document.
4 Classification
4.1 Basis of classification
Alkaline dense and shaped refractory products with a carbon content of less than 7% shall be classified according to the following conditions
a) Type of product;
b) grade, depending mainly on the magnesium oxide content and the presence or absence of antioxidants;
c) raw material characteristics;
d) form of bonding;
e) post-processing.
4.2 Types of products
The following general symbols are used to indicate the type of product:
a) Magnesium (M) ;
b) delivered calcium (ML);
c) dolomitic (MD);
d dolomitic (D>.)
e) Sending aluminous (MSp>;
f magnesia olivine (F);
e) chrome-feeding (MCr);
h) chromium-iron (Cr);
iCalcium oxide (L);
j) MZ;
k) cobalt-siliceous (MZs).
Note: L-lime and/or MgO-CaO co-sintered material; D-natural sintered dolomite -
GB/T 4984, GB/T 5069, GB/T 5070, GB/T 16555, GB/T 21114 or GB/T 34332 should be used for chemical analysis of the calcined specimens, and the results should be classified into product types according to Table 1 and Table 2.
4.3 Grades
Each product type should be further divided into different grades according to Table 1 and Table 2. The classification of the grades should be based mainly on the magnesium oxide content of each product type. In some products (ML.MD.D.L.Cr.MZ.MZS) the content of other major oxides is specified; if antioxidants are included an "A" is added to the grade.
4.4 Raw material characteristics
Raw materials shall be classified according to one or more of the following categories:
a) natural materials (raw or sintered):
b) Sintered synthetic materials;
c) Co-sintered materials (e.g. magnesium-chromium sand. magnesium-calcium sand):
d) Fused materials.
4.5 Forms of bonding
The different forms of bonding should be classified as follows:
a) ceramic bonding; at a certain temperature, due to sintering or liquid phase formation and the bonding,
b) organic chemical bonding: bonding formed by the hardening of organic substances at room temperature or at higher temperatures
c) inorganic chemical bonding: bonding formed by chemical reaction at room temperature or below 800 °C:
d) fusion casting; products made by complete melting at high temperatures.
4.6 Post-treatment
Post-treatment should be classified in one or both of the following ways;
a) Heat treatment (up to 800 °C.)
b) Impregnation
Note: There can be no post-treatment.
5 Designation
The nomenclature of alkaline dense and shaped refractory products with a carbon content of less than 7% shall be based on the classification in Chapter 4 (product type, grade, raw material characteristics. Combination form. The sequence of the products (type of product, grade, raw material characteristics, form of bonding, finish) is described in chapter 4.
Example 1: Magnesium-chromium products, MCr60, sintered synthetic magnesium sand and natural chrome sand raw materials. A porcelain bond
Example 2: Autolithic product - D4o, natural sintered autolithic raw material - ceramic bonding day
Example 3: Magnesia, M95 - sintered synthetic magnesia, organic chemical bonding, heat treated and impregnated
