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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 4000-2008 Coke - Determination of Reactivity and Strength after Reaction, the following main technical content changes have been made with respect to GB/T 4000-2008 (the previous edition):
——normative references are modified;
——test instruments and materials are modified;
——sampling and preparation of specimen are modified;
——test procedures are modified;
——requirements for precision are modified;
——Annex D Test Records is modified.
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 (SAC/TC 469/SC 3).
The previous editions of standard replaced by this standard are as follows:
——GB 4000-1983, GB/T 4000-1996 and GB/T 4000-2008.
Determination of Coke Reactivity Index (CRI) and Coke Strength after Reaction (CSR)
1 Scope
This standard specifies the principle, test instruments, equipment and materials, sampling and preparation of specimen, test procedures, result calculation and precision of determination of coke reactivity index (CRI) and coke strength after reaction (CSR).
This standard is applicable to the determination of reactivity index and strength after reaction of the coke for iron smelting in blast furnace, and it may be referred to the determination of reactivity index and strength after reaction of the coke for other purpose.
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
YB/T 4494 Technical Specification of Mechanical Sample Preparation for Measuring Coke Reactivity Index and Coke Strength after Reaction
3 Principle
Weigh a certain amount of coke specimen and place in a reactor; after reacting with carbon dioxide at 1100℃ for 2h, the Coke Reactivity Index (referred to as CRI) is expressed as a percentage of coke mass loss.
After the coke reacts, it’s subject to Type I drum test, and the Coke Strength After Reaction (referred to as CSR) is expressed as a percentage of the mass of coke with size greater than 10mm and that of coke after reaction.
4 Test instruments, Equipment and Materials
4.1 Electric furnace
Electric furnace wire, silicon carbide or other heating element meeting test requirements may be used for electric furnace. In the furnace, the length of (1100±3)℃ thermostatic area is not less than 150mm; a three-section heating furnace (schematic diagram is shown in Figure 1) is preferably adopted to ensure that the temperature of the gas entering into the specimen layer and the temperature in the whole specimen layer are kept at (1100 ± 3) ℃ where carbon dioxide reacts with coke specimen. Single-point temperature-measuring heating furnace may also be adopted, see Annex A.
In mm
Keys:
1——upper-section electric furnace;
2——upper-section temperature-measuring couple;
3——middle-section electric furnace;
4——middle-section temperature-measuring couple;
5——lower-section electric furnace;
6——lower-section temperature-measuring couple;
Figure 1 Schematic Diagram for Three-section Heating Furnace
4.2 Temperature control device
4.2.1 Requirements for temperature control
The temperature control device is able to display the upper, middle and lower temperature of the specimen layer in real time in test state to ensure that the temperature of the gas entering into the specimen layer and the temperature of the whole specimen layer are kept at (1100 ± 3)℃ where carbon dioxide reacts with coke specimen .
4.2.2 Temperature controller
4.2.2.1 Temperature control precision: (1100 ± 3)℃.
4.2.2.2 Precision grade: not lower than Grade 0.2.
4.2.3 Three-point thermocouple (see Figure 2 for its schematic diagram)
S-type; not lower than industrial Grade II; the measuring terminals of thermocouple are located in the upper, middle and lower parts of specimen center respectively.
In mm
Keys:
1——upper-section temperature-measuring couple;
2——middle-section temperature-measuring couple;
3——lower-section temperature-measuring couple.
Figure 2 Schematic Diagram for Three-point Thermocouple
4.3 Reactor (see Figure 3 for its schematic diagram)
4.3.1 Material of reaction tube: GH3044.
4.3.2 Wall thickness of reaction tube: ≥ 1.5mm.
4.3.3 Inside diameter of reaction tube: ф80 ± 1mm.
4.3.4 Feeding sieve slice: ф78±1mm, uniformly drilled with round hole of ф3mm with pore pitch of 5mm and sieve slice thickness of 1.5mm.
Foreword i
1 Scope
2 Normative References
3 Principle
4 Test instruments, Equipment and Materials
5 Sampling and Preparation of Specimen
6 Test Procedures
7 Result Calculation
8 Precision
Annex A (Informative) Single-point Temperature-measuring Heating Furnace
Annex B (Informative) Gas Purifying Devices for Carbon Dioxide and Nitrogen
Annex C (Informative) Quick Quantitative Drying Method for Coke Moisture
Annex D (Normative) Test Records
Annex E (Informative) Verification Method for Thermostatic Area of Electric Furnace
Bibliography
