This standard specifies two methods for determining the sulfur content of various types of carbon black: Method A - oxygen bomb calorimeter method; Method B - combustion furnace method. This standard is applicable to the determination of sulfur content of various types of carbon black. GB/T 3780.14-1995 Determination of sulfur content of carbon black GB/T3780.14-1995 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Determination of sulfur content of carbon black
Carbon hlack-Determinatlon
of sulphur content
This standard is equivalent to the international standard 1S0H38-1981 Rubber compounding agent-1 Subject content and scope of application
This standard specifies two methods for determining the sulfur content of various types of carbon black: Method A.
This standard is applicable to the determination of the sulfur content of various types of carbon black. 2 Reference standards
GB3778: Technical conditions for carbon black for rubber
GB/T 3780.8 Determination of blackening heating loss G16682 Specifications and experimental methods for water used in analytical laboratories HG/T2725 Sampling method for bulk carbon black
GB/T 3780.14-1995
Replaces GB/T 3785.14-83
Determination of sulfur content".
Oxygen bomb calorimeter method; Method B
Part I Method A
Oxygen bomb calorimeter method
3 Principle
Combustion furnace
Put the weighed dry carbon black sample into the oxygen bomb calorimeter and burn it. After opening the oxygen bomb, rinse its inner surface with water, collect the wash with a beaker, collect and weigh the sulfur precipitated in the form of barium sulfate in the wash, and calculate the percentage of sulfur. 4 Reagents
During the determination, use analytical reagents. Use distilled water or water of equivalent purity, which should meet the requirements of grade 3 water in GR6682. 4.1 Chlorinated solution: 100g/L.
Barium chloride (BaCl2) containing two crystals: 2H2O>100g of the solution is dissolved in water and diluted to 1000mL: 4.2 Hydrochloric acid: pul.19 g/cm2
4.32.4,6-Trinitrocarbophenol (picric acid) saturated solution Add excess picric acid to a stoppered glass bottle filled with water. Shake the bottle thoroughly to dissolve enough picric acid to saturate the solution. After saturation, a small amount of picric acid should remain in the solution. 4.4 Oxygen
Sufficiently pure (sulfide-free) oxygen stored in a steel cylinder for industrial use. Approved by the State Administration of Technical Supervision on December 20, 1995 and implemented on August 1, 1996
5 Instruments
Conventional laboratory instruments and!
GB/T 3780. 14--1995
5.1 Oxygen bomb calorimeter: with ignition transformer, ignition wire, equalizing crucible with fuel container, elliptical cylinder, calorimetric curtain, electric stirrer for water circulation around the oxygen bomb, and calorimeter hygrometer with a range of 19~-35℃ and a graduation of 0.02L. 5.2 Ammonia cylinder: with connector and regulator connected to the oxygen bomb calorimeter. 5.3 Crucible: porcelain, volume 30ml.
5.4 Constant temperature drying oven: the temperature can be controlled at i05±2℃. 5.5 Ma Furnace, the temperature can be controlled at 925 + 25 ℃. 5.6 Filter funnel: Bunsen type long tube filter funnel, with 60 ° angle slot. 5.7 Flat dryer.
6 Sampling
Bagged carbon black shall be carried out according to GH37781 5.2 provisions, bulk carbon black shall be carried out according to HG/T2725 provisions. 7 Steps
7.1 F coal according to the method specified in GB/T3780.8 for an appropriate amount of sample for 1 hour. Place the card dryer (5.7) in the preparation, 7.2 weigh about 0.5 5.3) into the ring electrode, and extend the fuse as required by the oxygen bomb type calorimeter manual until it is below the surface of the carbon black. 7.3 Take 5mL of water and put it into the oxygen bomb cylinder: install the oxygen bomb bottle and fill it with oxygen (4.1) (pressure is 3MPa) 7.4 At room temperature, add 2000mL of water to the calorimeter cylinder. Put the cylinder into the calorimeter and adjust the hydrogen bomb in the cylinder to make it Connect to the thrust end. After installing the thermometer, close the calorimeter and start the electric stirrer. Let the electric stirrer stir for 2 minutes. Then record the water temperature. Immediately close the ignition circuit to ignite the charge. If there is no indicator light on the ignition system, press the ignition button s before disconnecting the circuit. Observe the water temperature rise. In about 5 minutes, the water temperature should rise by 2 (if the humidity card rises, the test should be invalidated and the measurement should be restarted). After ignition, let the electric stirrer stir for a total of 10 minutes. It takes at least 1 minute to gradually release the pressure. 7.5 Open the oxygen bomb and rinse the inner surface with water. Collect the washings in a 250ml beaker. Filter the washings into a 100ml beaker and rinse the filter paper with three s ml of water. Add 5 ml of hydrochloric acid (1.2), 5 ml of saturated sodium hydroxide solution (4.3), and 10 ml of barium chloride solution to the filtrate. Heat the mixture on a hot plate at low temperature for about 15 minutes, then filter with ash-free filter paper, washing the precipitate on the filter paper with 1 ml of boiling water each time. Continue washing until the filtrate is tested with silver nitrate and no sodium chloride is found. 7.6 Transfer the filter paper with the precipitate to a porcelain flask (5.\) that has been burned to constant weight, weigh to the nearest 0.1 mg: use a high-temperature gas lamp, open flame, low flame to melt, ignite and burn, then transfer to a flask controlled at 925 ± 25 °C, after 30 minutes, transfer the flask and its contents to a drying device (5.7), cool it to room temperature, and weigh to the nearest 0.1 mg. Burn again until constant weight. 8. Expression of results
8.1 The total sulfur content of carbon black is expressed as a mass percentage and is calculated according to formula (1): 0.137 3(m:-m) × 10052
Formula mT Mass of dry sample ·
Mass of mi
m: Mass of the content of the ignited carbon black 8.0.1373——Sulfur content in sulfuric acid.
9 Allowable difference
G1/1 3780.14—1995
Allowable difference: The difference between two determination results shall not exceed 16% of the average value. 10 Test Report
The test report should include the following contents:
National standard number on which the test is based;
Mark, number and origin of the sample;
Half mean of two test results:
d. Test period.
Part II Method B
11 Principle
Combustion furnace method
Weigh the dried carbon black sample and burn it in a combustion furnace at 1425+25℃ in a continuous flow of oxygen. Collect the sulfide released from the sample in a titration bottle filled with hydrochloric acid solution, use potassium iodate-potassium iodide standard solution to absorb the absorption liquid in the titration bottle, and calculate the percentage of sulfur. 12 Reagents It is recommended to use fractionally pure reagents when determining. Use distilled water or water of equivalent purity. It should comply with the provisions of Taiwan GH6682. 12.1 Hydrochloric acid solution Mix 2 volumes of concentrated hydrochloric acid (p21.19 g/cm\) with 13 volumes of water. 12.2 Potassium iodate-potassium iodide standard solution Dissolve 1.1t25g potassium iodate (KIO), 100g potassium iodide (K1) and 5g potassium hydroxide (KOH) in about 500mL distilled water and dilute to [000] in a volumetric flask. ml.
Note: The solution should be stored in a brown or green glass bottle. It is best to prepare a fresh solution every 30 days: 12.3 Starch indicator solution
Dissolve 2.5 g starch in 1010 ml distilled water for later use. 5 mg iodide (Hg12). 12.4 Oxygen
The oxygen from industrial cylinders is of sufficient purity (sulfide-free). 13 Apparatus
Routine test instruments and:
13.1 Combustion chamber: Suitable for use at 1425℃ and 25℃. 13.2 Combustion chamber: Long 75 cm long with a conical end. 13.3 Combustion boat: Made of sintered oxygen nitrile (steel) or porcelain. Note: Before using a new combustion boat, heat it at 125±25℃. 13.4 Pressure regulator and flow meter.
13.5 Oxygen purification system: It consists of a gas washing bottle filled with dilute sulfuric acid (H2SO4) (1.84°C/cm3) and a water absorption bottle filled with a mixture of caustic soda and anhydrous calcium sulfate saturated with carbon dioxide. 3.6 Gas dispersion vessel: Made of sintered polyvinyl chloride glass. 13.7 Triangular flask for titration; the volume is 500 mL. GB/T 3780.14-1995
13.8 Rubber stopper: It is equipped with a high-temperature heat reflector or baffle made of metal or refractory material. 13.9 Constant temperature drying oven: The temperature can be controlled at 105±2℃. 14 Sampling
Bagged carbon black according to GB3778 6.2. Bulk carbon black is heated according to HG/T2725. Step 15
15.1 Dry the appropriate carbon black sample for 1 hour according to the method specified in GB/T3780.8. Weigh about 1g of the carbon black sample, weigh to 0.1mg, and transfer it to the combustion boat (13.3):
15.2 Inject about one-half of the volume of hydrochloric acid solution (12.1) into the titration bottle (13.7), add 2ml of the powder indicator (12.3). Under stirring, add potassium iodate-potassium iodide solution (12.2) until a blue color appears. Insert the gas dispersion tube (13.6) into the titration bottle 1. 15.3 When the combustion furnace is heated to 1425℃ and an oxygen flow of 1000cm3 is passed per minute (see Note), the combustion tube containing the carbon black sample is placed into the hot area of ​​the combustion tube. The rubber stopper (13.8) is used to plug the explosion tube so that the gas released by the combustion passes through the gas dispersion tube (13.6). Use potassium iodate-potassium iodide solution to titrate the solution in the titration bottle so that it remains blue. After bubbling for 3 minutes, when the blue color in the titration bottle can be maintained without adding potassium iodate-potassium iodide solution, the end point is reached. Note: Before the continuous determination of each batch of carbon porridge samples, the combustion system should be swept 30 times with oxygen flow at a temperature of 1425 ± 25°C. 16. Expression of results
16.1 The total sulfur content of carbon black is expressed as mass white fraction, calculated according to formula (2): 20m
or; V---the volume of potassium iodide consumed in titration. Potassium iodide standard solution (12.2) + mL; m: the mass of the sample + g.
17. Allowable difference
Allowable difference: The difference between the two determination results shall not exceed 16% of the average value. 18. Test report
The test report shall include the following contents:
The national standard number on which this test is based;
Sample mark, number and origin;
The average value of the two test results;
d. Abnormal phenomena occurring during the test; www.bzxz.net
Test date.
Additional Notes:
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard was drafted by the Carbon Industry Research and Design Institute of the Ministry of Chemical Industry. The main drafter of this standard is.
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