GB/T 4000-1996 Test method for coke reactivity and post-reaction strength
Some standard content:
GB/T4000-1996
The sample preparation method of artificially modulated coke balls specified in GB4000-83 consumes too much man-hours and should be replaced by a more scientific, simple and easy method. For this reason, the sample preparation method has been revised this time, and other contents have been edited according to GB/T1.1-1993 and relevant technical specifications. From the date of entry into force of this standard, it will replace GB4000--83 at the same time. This standard was proposed by the Ministry of Metallurgical Industry of the People's Republic of China. The drafting unit of this standard is Shougang Iron and Steel Research Institute. The main drafters of this standard are Wu Jiting, Tang Quanqing and Lv Jin. 33
1 Scope
National Standard of the People's Republic of China
Test Method for Coke Reactivity and Strength after Reaction Coke--Determination of reactivity and strength after reaction GB/T4000--1996
Replaces GB100083
This standard specifies the method summary, test instruments, equipment and materials, sample collection and preparation, test procedures, calculation and precision of test results for determining the reactivity and strength of coke for blast furnace ironmaking. This standard is applicable to the determination of the reactivity and strength of coke for other purposes. 2 Referenced Standards
The provisions included in the following standards constitute the provisions of this standard through reference in this standard. At the time of publication of the standard, the versions shown are all valid. All standards will be revised. All parties using this standard should explore the possibility of using the latest versions of the following standards: GB1997--89 Collection and preparation of coke samples GB/T2006--94 Determination of mechanical strength of metallurgical coke 3 Principle
Weigh a fixed mass of coke sample and place it in a reactor. After reacting with carbon dioxide at 1000±5℃ for 2h, the coke reactivity (CRI%) is expressed as the percentage of coke mass loss. After the reaction, the coke, after the type 1 drum test, the mass percentage of coke with a particle size greater than 10mm in the coke after reaction is expressed as the post-reaction strength (CSR%).
4 Test instruments, equipment and materials
4.1 Electric furnace
The furnace structure is shown in Figure 1.
Approved by the State Administration of Technical Supervision on April 5, 19963
Implemented on October 1, 1996
GB/T4000--1996
Figure 1 Electric furnace
1 High-aluminum outer wire tube; 2--Fe-Cr-Aluminum furnace wire: 3, 4--Lightweight high-aluminum bricks; 5 Furnace shell; 6--Castors; 7-Furnace cover; 8 Insulators; 9--Temperature-controlled thermocouple The furnace has an inner diameter of 140mm, an outer diameter of 160mm, and a height of 640mm (high-aluminum outer wire tube). Electric furnace wire: high-temperature Fe-Cr-Aluminum alloy resistance wire, the highest operating temperature is 1400℃, and the diameter is 2.8mm. Key points for installing the electric furnace: The bottom of the furnace shell is sealed, the upper mouth is spread out, and the casters are pre-installed on the bottom plate. Lay a layer of refractory bricks on the bottom, and place the outer wire tube with the resistance wire wound upright in the middle of the bottom plate. Fill the gap between the outer wire tube and the furnace shell with lightweight high-aluminum brick prefabricated parts (cut from standard-sized lightweight high-aluminum bricks), and lead the furnace wire from the upper and lower ends to connect with the insulator fixed on the furnace shell. The lead-out part of the furnace wire is protected by a single-hole insulating tube, and it is forbidden to overlap the five machines to avoid short circuit. Pre-drill a hole with a diameter of 8mm on the insulation brick outside the outer wire tube close to the outside of the furnace wire, and the depth is 350mm from top to bottom. Bury the thermocouple sleeve, cover the upper cover, insert the temperature control thermocouple, connect the electric furnace with the temperature controller and the power supply, and measure the constant temperature zone after each electric furnace is installed, so that the length of the 1100±5°C temperature zone in the furnace is greater than 150mm. 4.2 The structure of the reactor is shown in Figure 2, which is made of high-temperature resistant alloy steel (GH23 or GH44). 3
Figure 2 Reactor
GB/T4000—1996
Central thermocouple tube; 2--Intake pipe; 3--Exhaust pipe 4.3 Post-reaction strength test equipment
4.3.1 T-type drum: The device is shown in Figure 3. Speed 20±1.5r/min. Figure 31-type drum
1 Drum body; 2: Motor; 3 Speed reducer; 4--Frame 4.3.1.1 Drum body: Made of 140mm, 5~6mm thick seamless steel pipe. 4.3.1.2 Speed reducer: Speed ratio 50 (WHT08 type). 4.3.1.3 Motor: 0.75kW, 910r/min (Y905--6) 4.3.2 Drum controller: Total number of revolutions 600r. Time 30min. 4.4 Carbon dioxide supply system
4.4.1 Carbon dioxide cylinder and oxygen pressure gauge. The carbon dioxide content in the cylinder is greater than 98%. 4.4.2 Rotor flowmeter: 0.6m2/h.
4.4.3 Washing bottle: volume 500mL, filled with concentrated sulfuric acid (p--1.84g/ml.). 4.4.4 Lower drying tower: volume 500mL, filled with anhydrous calcium fluoride. 4.4.5 Buffer bottle: volume 6000ml.
4.5 Nitrogen supply system
4.5.1 Nitrogen cylinder and oxygen pressure gauge. The nitrogen content in the cylinder is greater than 98%. 4.5.2 Rotor flowmeter: 0.25m/h
4.5.3 Washing bottle: volume 500ml, filled with alkaline solution of pyrogallic acid. Preparation method: 5g pyrogallic acid is dissolved in 15ml water, 48g potassium hydroxide is dissolved in 32mL water, and the two are mixed. Be careful to prevent air oxidation during preparation. 4.5.4 Drying tower: volume 500mL, filled with anhydrous block calcium chloride, 4.5.5 When using high-purity nitrogen (nitrogen content 99.99%), the washing bottle 4.5.3 and the drying tower 4.5.4 are not required. 4.6 Precision temperature control device
Temperature control range: 0~1600℃, accuracy ±0.5℃, without isolation transformer. 4.7 Gas analyzer
GB/T4000—1996
Simple gas analyzer or other instrument for accurately measuring carbon dioxide content. 4.8 Round hole sieve
18mm, 15mm, 10mm, 5mm3mm, 1mm each, sieve diameter 200mm, 21mm and 25mm each, sieve surface 400mm×500mm, manufactured in accordance with the provisions of round hole sieve in Article 4.2 of GB/T2006. 4.9 Drying box
TThe volume of the working room is not less than 0.07m.
Maximum temperature: 300℃.
4.10 Pan balance
Maximum weighing 500g, sensitivity 0.5g.
4.11 Infrared bulb
220V, 250W
4.12 Platinum thermocouple
Diameter 0.5mm, length 700mm
High aluminum thermocouple protection tube AΦ7×5×400 (mm) High aluminum double hole insulation tube
High aluminum single hole insulation tube
4.13 Sieve plate
D $4X1X400(mm)
C $1X0.6X10(mm)
Material is Xie high temperature alloy steel (GH23 or GH44), thickness 3mm, diameter 79mm, all holes with diameter 3mm are drilled on it, and the distance between holes is 5mm.
4.14 High aluminum ball
Diameter 20mm.
4.15 Bracket
As shown in Figure 4. Material Q235A, three branch pipes are made of 1Gr18Ni9Ti. 14×3
Bracket in Figure 4
4.16 Reactor bracket
Hold the reactor, size and form are optional.
5 Sample collection and preparation
5.1 According to the sampling method specified in GB1997, take 20kg of coke larger than 25mm in proportion, and discard the foam coke and furnace head coke. Use a jaw crusher to crush, mix and reduce 10kg, then use +25mm and 21mm round sieves to screen, crush and screen the coke blocks larger than Φ25mm, take the +21mm screened material, remove the flake coke and strip coke, reduce and obtain 2kg of coke blocks, put them in a "-shaped drum twice (1kg each time), rotate at a speed of 20r/min, rotate 50r, take them out and use a 21mm round hole sieve to screen, reduce the screened material to 900g as a sample, and use the quartering method to divide the sample into 37
four parts, each part is not less than 220g.
GR/T 4000-
--1996
The coke for the experimental coke oven can be prepared with coke of 10mm~60mm particle size5.2 Put the prepared sample into the drying oven, dry it at 170~180℃ for 2h, take out the coke and cool it to room temperature, weigh 200g+-09 for standby use,
6 Test steps
The test process is shown in Figure 5.
Figure 5 Test flow chart
1-Carbon dioxide cylinder, 2-Needle valve; 3-Buffer bottle; 4·Concentrated sulfuric acid washing bottle; 5, 13-Drying tower; 6-Glass three-way piston; 7Precision temperature control device, 8Thermocouple; 9-Gas analyzer; 10Nitrogen cylinder: 11, 19Rotameter: 12Pyrogallic acid washing bottle; 14Bracket; 15Sample; 16Reactor; 17Electric furnace; 18Infrared lamp
6.1Put a layer of high aluminum balls about 100mm high on the bottom of the reactor, and place the sieve plate flat on it. Then load the prepared coke sample 200g0.5g into the inlet. Pay attention to adjusting the height of the high-aluminum ball before loading the sample, so that the coke layer in the reactor is in the constant temperature zone of the electric furnace. Insert the thermocouple sleeve connected to the upper cover into the center of the material layer. Fix the cover to the reactor body with screws. Hang the bracket on the top of the reactor into the electric furnace. Place asbestos boards between the support beam and the electric furnace cover for insulation. Place high-aluminum lightweight bricks (cut from standard-sized high-aluminum lightweight bricks, the size is arbitrary) around the reactor flange to reduce heat dissipation.
6.2 Connect the reactor air inlet pipe and exhaust pipe to the gas supply system and exhaust system respectively. Insert the temperature measuring thermoelectric corner into the reactor thermoelectric corner gas tube (the thermoelectric corner is protected by a high-aluminum double-hole insulation tube and a high-aluminum thermoelectric corner protection tube). Check the gas circuit to ensure it is tight. 6.3 Turn on the power supply and use the precision temperature control device to adjust the heating of the electric furnace. First use manual adjustment, the current is adjusted from small to large, within 15min, and gradually adjusted to the maximum value, and then turn the button to the automatic position. The heating rate is 8~16C/min. When the temperature at the center of the material layer reaches 400℃, circulate nitrogen at a rate of 0.8L./min to protect the coke and prevent it from burning. 6.4 When the temperature at the center of the material layer reaches 1050℃, turn on the infrared lamp to preheat the outlet of the carbon dioxide cylinder. When the temperature at the center of the material layer reaches 1100℃, cut off the nitrogen and switch to carbon dioxide at a flow rate of 51./min for 2h. After the carbon dioxide is passed, the temperature of the material layer should return to 1100±5℃ within 5~10min. 5min after the reaction starts, take gas from the exhaust system for analysis and take gas every half an hour to analyze the carbon monoxide or carbon dioxide content in the gas after the reaction.
6.5 React for 2 hours and stop heating. Cut off the carbon dioxide gas line and switch to nitrogen, with the flow rate controlled at 2L/min. Unplug the exhaust pipe. Quickly remove the reactor from the electric furnace, place it on the bracket and continue to pass nitrogen to cool the coke to below 100C, stop passing nitrogen, open the reactor top, pour out the coke, sieve, weigh and record.
6.6 Load all the reacted coke into a type 1 drum and rotate it at a speed of 20r/min for a total of 30 minutes. The total number of revolutions is 600r. Then take out the coke for sieve, weigh and record the mass of each sieve grade. 38
GB/T 4000
6.7 The sieve composition obtained in the test, the gas composition after the reaction, and other observed phenomena shall be recorded in detail according to the original record table and analyzed as a reference for comprehensive investigation of the coke properties. 6.8 The original test data shall be recorded in the format shown in Table 1. 7 Calculation of test results
7.1 Coke reactivity
The coke reactivity index is expressed as the percentage of the lost coke mass to the total mass of the coke sample before the reaction. Coke reactivity CRI% is calculated according to formula (1)
CRI(%)-
Where: m—coke test mass Sample mass, 8;
-mass of coke residue after reaction, g.
7.2 Strength after reaction
The strength after reaction index is expressed as the mass percentage of coke with particle size greater than 10 mm after drumming to the mass of coke residue after reaction. Strength after reaction CSR% is calculated according to formula (2):
CSR(%)=
Wherein: m2-mass of coke with particle size greater than 10 mm after drumming, g. 8 Precision
8.1 The repeatability r of coke reactivity CRI and strength after reaction CSR shall not exceed the following values: CRI: r≤.2. 4%,
CSR:r≤3.2%
8.2 The test results of coke reactivity and strength after reaction are taken as the arithmetic mean of parallel tests. (2)
Sample name:
Test start time
Start nitrogen flow time
(temperature 400C)
Start carbon dioxide flow
Time (material layer temperature
1100℃)
End test time
Sieve composition of coke after reaction
mm mass, g mass, % mass.g mass, %s
Reactivity
Average reactivity, %
GB/T4000--1996
cO2. % cO.%
Coke drum test after reaction
Particle size composition
Mass, g mass, % mass, 8 mass, %Strength after reaction, %
Average value of strength after reaction, %
Mass, % mass, %
k3mm, %
Average, %
Phenomena observed
in the test
Operator1 The repeatability r of coke reactivity CRI and post-reaction strength CSR shall not exceed the following values: CRI: r≤.2.4%,
CSR: r≤3.2%
8.2 The test results of coke reactivity and post-reaction strength shall be the arithmetic mean of parallel tests. (2)
Sample name:
Test start time
Nitrogen start time
(temperature 400C)
Carbon dioxide start time
Time (bed temperature
1100℃)
Test end time
Sieving composition of coke after reaction
mm mass, g mass, % mass.g mass, %s
Reactivity
Average reactivity, %
GB/T4000--1996
cO2. % cO.%
Coke drum test after reaction
Particle size composition
Mass, g mass, % mass, 8 mass, %Strength after reaction, %
Average value of strength after reaction, %
Mass, % mass, %
k3mm, %
Average, %
Phenomena observed
in the test
Operator1 The repeatability r of coke reactivity CRI and post-reaction strength CSR shall not exceed the following values: CRI: r≤.2.4%,bzxz.net
CSR: r≤3.2%
8.2 The test results of coke reactivity and post-reaction strength shall be the arithmetic mean of parallel tests. (2)
Sample name:
Test start time
Nitrogen start time
(temperature 400C)
Carbon dioxide start time
Time (bed temperature
1100℃)
Test end time
Sieving composition of coke after reaction
mm mass, g mass, % mass.g mass, %s
Reactivity
Average reactivity, %
GB/T4000--1996
cO2. % cO.%
Coke drum test after reaction
Particle size composition
Mass, g mass, % mass, 8 mass, %Strength after reaction, %
Average value of strength after reaction, %
Mass, % mass, %
k3mm, %
Average, %
Phenomena observed
in the test
Operator
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