ICS 75.160.10
H 32
National Standard of the People’s Republic of China
GB/T 2286-2017
Replaces GB/T 2286-2008
Determination of total sulfur composition of coke
焦炭全硫含量的測(cè)定方法
(English Translation)
Issue date: 2017-10-14 Implementation date: 2018-05-01
Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
the Standardization Administration of the People’s Republic of China
Contents
Foreword i
1 Scope 1
2 Normative references 1
3 Eschka method (arbitration method) 1
4 High-temperature combustion method 5
5 Coulometric titration 10
6 Infrared spectroscopy 15
7 Expression of results 18
8 Test report 18
Foreword
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 2286-2008 Coke - Determination of total sulfur. The following technical changes have been made with respect to GB/T 2286-2008:
——The "semi-coke” has been added (see Clause 1 hereof);
——GB/T 2001 and GB/T 8170 have been added into the normative references (see Clause 2 hereof);
——"Aldrin" has been modified to "Eschka reagent" (see Clause 3 hereof);
——"4.3.7 Acid burette; 4.3.8 Alkali burette; 4.3.9 Ear syringe; 4.3.10 Measuring cylinder; 4.3.11 Analytical balance" have been added into 4.3 Apparatus (see 4.3);
——Equation (3) in 4.6.1 has been modified (see 4.6.1 hereof);
——The coulometric titration has been added (see Clause 5 hereof);
——The infrared spectroscopy has been added (see Clause 6 hereof).
This standard was proposed by China Iron and Steel Association.
This standard is under the jurisdiction of SAC/TC 469/SC 3 Coking Chemical Subcommittee of National Coal Chemical Industry Technical Committee of Standardization Administration of China.
The previous editions of this standard are as follows:
——GB 2286-1980, GB/T 2286-1991 and GB/T 2286-2008.
Determination of total sulfur composition of coke
Warning: The use of this standard involves some dangerous materials, operations and equipment, but it does not purport to address all of the safety concerns, if any, associated with it. It is the responsibility of the user to establish appropriate safety and protection practices before using this standard and to ensure compliance with any national regulatory conditions.
1 Scope
This standard specifies the principles, reagents and materials, apparatus, sampling of specimen, test procedures, result calculation and precision of the Eschka method, high-temperature combustion method, coulometric titration and infrared spectroscopy for determining the total sulfur composition of coke.
This standard is applicable to coke and semi-coke.
2 Normative references
The following referenced 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 601 Chemical reagent - Preparations of reference titration solutions
GB/T 1997 Coke - Sampling and preparation of samples
GB/T 2001 Coke - Determination of proximate analysis
GB/T 8170 Rules of rounding off for numerical values & expression and judgement of limiting values
3 Eschka method (arbitration method)
3.1 Principle
The specimen is thoroughly mixed with Eschka reagent and burned at a certain temperature to convert sulfur in the specimen into sulfate. Then, the sulfate ions generate barium sulfate precipitate, and the total sulfur content in the specimen is calculated according to the mass of barium sulfate.
3.2 Reagents and materials
Unless otherwise specified, only the reagents recognized of analytical quality and distilled water or deionized water or water with equivalent purity shall be used during the analysis.
3.2.1 Magnesium oxide: chemically pure.
3.2.2 Anhydrous sodium carbonate: chemically pure.
3.2.3 Eschka reagents: weigh 2 portions by mass of magnesium oxide and 1 portion by mass of anhydrous sodium carbonate, grind them until the particle size is less than 0.2 mm, mix them evenly, and store them in a closed container.
3.2.4 Hydrogen peroxide: with a concentration of 30%.
3.2.5 Hydrochloric acid solution: with a density of 1.19 g/cm3.
3.2.6 Nitric acid: with a density of 1.42 g/cm3.
3.2.7 Barium chloride solution (100g/L): weigh 100g of barium chloride, dissolve it in water, and dilute it to 1,000mL with water.
3.2.8 Hydrochloric acid solution (1+1), 1 portion by volume of hydrochloric acid being mixed with 1 portion by volume of water.
3.2.9 Silver nitrate solution (10g/L): weigh 1g of silver nitrate, dissolve it in water, dilute it to 100mL with water, add a few drops of nitric acid, and store it in a dark bottle.
3.2.10 Methyl red indicator solution (1 g/L): weigh 0.1 g of methyl red, dissolve it in 50 mL of ethanol, and dilute it to 100 mL with water.
3.2.11 Qualitative filter paper: medium speed, Φ90mm to Φ110mm.
3.2.12 Quantitative filter paper: medium speed, Φ90mm to Φ110mm.
3.3 Apparatus
3.3.1 Analytical balance: with a sensibility of 0.0001g.
3.3.2 Tray balance: with a sensibility of 0.01g.
3.3.3 Muffle furnace: with temperature control device, which can maintain the temperature of 800℃ to 850℃, the temperature can be adjusted, and the furnace can be ventilated.
3.3.4 Desiccator: containing color-changing silica gel or granular anhydrous calcium chloride.
3.3.5 Beaker.
3.3.6 Porcelain crucible: two types, one with a capacity of 30mL and the other 20mL.
3.4 Specimen preparation
As specified in GB/T 1997.
3.5 Test procedures
3.5.1 Weigh 2g (accurate to 0.1 g) of Eschka reagents (see 3.2.3) and 1g (accurate to 0.0001 g) of specimens with particle size less than 0.2 mm in a 30mL porcelain crucible (see 3.3.6), mix evenly with nickel-chromium wire, and then cover the specimen with 1g (accurate to 0.1 g) of Eschka reagent (see 3.2.3).
3.5.2 Move the crucible containing the specimen into the muffle furnace (see 3.3.3), and gradually raise the furnace temperature to 800℃ to 850℃ within 1h to 1.5 h, and heat at this temperature for 1 h to 1.5 h.
3.5.3 Remove the crucible from the muffle furnace, cool it to room temperature, and stir the burned material with a glass rod (if unburned specimen particles are found, continue to burn it at 800℃ to 850℃ for 0.5 h), move it into a beaker, carefully rinse the inner wall of the crucible with hot water, add the rinsing solution into the beaker, then add 100mL to 150mL of hot water, and mash the burned material with a glass rod (if there are still unburned specimen particles found at this time, this test will be invalid).
3.5.4 Add 1 mL of hydrogen peroxide (see 3.2.4) into a beaker, heat it to 80 °C℃ and hold for 30 min.
3.5.5 Filter through qualitative filter paper (see 3.2.11) and rinse the burned material onto the filter paper with hot distilled water. Continue to carefully rinse the burned material on the filter paper with hot distilled water for not less than 10 times.
3.5.6 Boil the filtrate for 2min to 3min to discharge excess hydrogen peroxide, and add 2 to 3 drops of methyl red indicator solution (see 3.2.10) to the filtrate to indicate whether all the excess hydrogen peroxide is discharged. Add hydrochloric acid solution (see 3.2.8) dropwise until the color turns red, add an additional 1mL, and boil for 5min to remove carbon dioxide. At this time, the volume of the solution is about 200mL.
3.5.7 Cover the beaker with the watch glass, reduce the amount of heating until the solution stops boiling, remove the watch glass, slowly drop 10mL of barium chloride solution (see 3.2.7) into the hot solution, stir the solution at the same time, cover the watch glass, and keep the solution at a temperature slightly below the boiling point for 30min.
3.5.8 After cooling, the solution is filtered through quantitative filter paper (see 3.2.12) and washed with hot water until there is no chloride ion [without turbidity when checked with silver nitrate solution (see 3.2.9)].
3.5.9 Transfer the precipitate together with the filter paper into a 20mL porcelain crucible of known mass (see 3.3.6), first ash the filter paper at low temperature, and then transfer it into a muffle furnace with a temperature of 800℃ to 850℃ to burn it for 20 min, take out the crucible, put it in a desiccator (see 3.3.4) after slightly cooling, and cool it to room temperature and weigh.
3.5.10 Blank test: Blank test shall be carried out for every batch of specimens, every batch of Eschka reagents prepared or when any other reagent is replaced. Except that no specimen is added, other test procedures are the same as 3.5.1 to 3.5.9.
Foreword i
1 Scope
2 Normative references
3 Eschka method (arbitration method)
4 High-temperature combustion method
5 Coulometric titration
6 Infrared spectroscopy
7 Expression of results
8 Test report
