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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 1996-2003 Coke for Metallurgy. The following main technical content changes have been made with respect to GB/T 1996-2003 (the previous edition):
——normative references are modified (see Chapter 2);
——terms and definitions are deleted (see Chapter 3 of 2003 edition);
——sulfur content St,d index is modified, with Grade I changed to ≤0.70% from ≤0.60%, Grade II to ≤0.90% from ≤0.80% and Grade III to ≤1.10% from ≤1.00% (see Table 1 in 3.1);
——crushing strength M25 index is modified, with Grade II changed to ≥89.0% from ≥88.0% and Grade III to ≥85.0% from ≥83.0% (see Table 1 in 3.1);
——crushing strength M40 index is modified, with Grade I changed to ≥82.0% from ≥80.0%, Grade II to ≥78.0% from ≥76.0% and Grade III to ≥74.0% from ≥72.0% (see 3.1 in Table 1);
——wear resistance M10 index is modified, with Grade I changed to ≤7.0% (see Table 1 in 3.1);
——strength after reaction (CSR) index is modified, with Grade I changed to ≥60% from ≥55% and Grade II to ≥55% from ≥50% (see Table 1 in 3.1);
——coke dry quenching moisture content (Mt) ≤ 2.0% is added (see Table 1 in 3.1);
——coke wet quenching moisture content (Mt) is changed to ≤7.0% (see Table 1 in 3.1);
——dust coke content is changed to ≤ 5.0% (see Table 1 in 3.1);
——requirements of "reactivity index and strength after reaction data shall be provided when required by the user" are deleted (see 4.4 of 2003 edition);
——inspection rules are added (see Chapter 5);
——Annex A is deleted (see Annex A of 2003 edition).
This standard was proposed by China Iron and Steel Association.
This standard is under the jurisdiction of Coking Chemical Subcommittee of National Coal Chemical Industry Technical Committee of Standardization Administration of China (SAX/TC 469/SC 3).
The previous editions of standard replaced by this standard are as follows:
——GB/T 1996-1980, GB/T 1996-1994 and GB/T 1996-2003.
Coke for Metallurgy
1 Scope
This standard specifies the technical requirements, test methods, inspection rules, transportation and quality certificate of coke for metallurgy.
This standard is applicable to the coke for smelting in blast furnace.
2 Normative References
The following documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 1997 Coke - Sampling and Preparation of Samples
GB/T 2001 Coke - Determination of Proximate Analysis
GB/T 2005 Coke for Metallurgy - Determination of Coke Breeze Content and Size Consist
GB/T 2006 Coke for Metallurgy - Determination of Mechanical Strength
GB/T 2286 Determination of Total Sulfur Composition of Coke
GB/T 4000 Determination of Coke Reactivity Index (CRI) and Coke Strength after Reaction (CSR)
GB/T 8170 Rules of Rounding off for Numerical Values & Expression and Judgment of Limiting Values
3 Technical Requirements
3.1 The technical index of coke for metallurgy shall be in accordance with those specified in Table 1.
3.2 Through negotiation between the supplier and the purchaser, the crushing strength may be supplied according to M25 or M40. If not specified, it is supplied according to M40.
3.3 Moisture and dust coke content are not used as basis for quality assessment.
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Table 1 Technical Indexes of Coke for Metallurgy
Index Grade Size/mm
>40 >25 25~40
Ash content (Ad )/% Grade I
Grade II
Grade III ≤12.0
≤13.5
≤15.0
Sulfur content St,d (mass fraction)/% Grade I
Grade II
Grade III ≤0.70
≤0.90
≤1.10
Mechanical strength Crushing strength (M25)/% Grade I
Grade II
Grade III ≥92.0
≥89.0
≥85.0 Negotiated through the supplier and the purchaser
(M40)/% Grade I
Grade II
Grade III ≥82.0
≥78.0
≥74.0
Wear resistance (M10)/% Grade I
Grade II
Grade III ≤7.0
≤8.5
≤10.5
Coke reactivity index (CRI)/% Grade I
Grade II
Grade III ≤30
≤35
—
Coke strength after reaction (CSR)/% Grade I
Grade II
Grade III ≥60
≥55
—
Volatile (Vdaf )/% ≤1.8
Moisture content (Mt )/% Coke dry quenching ≤2.0
Coke wet quenching ≤7.0
Dust coke content/% ≤5.0
Note: % is the mass fraction.
4 Test Methods
4.1 Measurement of moisture, ash content and volatile content is carried out according to GB/T 2001.
4.2 Measurement of total sulfur is carried out according to GB/T 2286.
4.3 Measurement of mechanical strength is carried out according to GB/T 2006.
4.4 Measurement of reactivity index and strength after reaction is carried out according to GB/T 4000.
4.5 Measurement of dust coke and composition through sieving is carried out according to GB/T 2005.
5 Inspection Rules
5.1 The quality supervision department of the supplier shall conduct the quality inspection of coke for metallurgy and the user is entitled to conduct the acceptance according to this standard.
5.2 The sampling and preparation of coke specimen shall be carried out according to the requirements of GB/T 1997.
5.3 The rounding off of numerical value is carried out according to the requirements of GB/T 8170.
5.4 Where the purchaser has any objection to the quality during acceptance, it shall be settled through negotiation between the supplier and the purchaser.
6 Transportation and Quality Certificate
6.1 The products are transported in a clean train compartment, car or other means.
6.2 Each lot of products shall be accompanied with quality certificates of which the contents shall include: supplier’s name, product name, standard No., quality grade, lot No., gross weight, net weight, vehicle number, delivery date and various test results specified in this standard, etc.
Foreword i
1 Scope
2 Normative References
3 Technical Requirements
4 Test Methods
5 Inspection Rules
6 Transportation and Quality Certificate
