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GB/T 2286-2017 PDF English (GB/T 2286-2008: Older version)Search result: GB/T 2286-2017 (GB/T 2286-2008 Older version)
GB/T2286-2017 (GBT2286-2017): PDF in EnglishGB/T 2286-2017 GB NATIONAL STANDARD OF THE PEOPLE’S REPUBLIC OF CHINA ICS 75.160.10 H 32 Replacing GB/T 2286-2008 Determination of total sulfur composition of coke ISSUED ON: OCTOBER 14, 2017 IMPLEMENTED ON: MAY 01, 2018 Issued by: General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China; Standardization Administration of the People's Republic of China. Table of Contents Foreword ... 3 1 Scope ... 4 2 Normative references ... 4 3 Eschka method (arbitration method) ... 4 4 High temperature combustion method ... 8 5 Coulometric titration method ... 12 6 Infrared spectroscopy method ... 16 7 Result expression ... 19 8 Test report ... 19 Determination of total sulfur composition of coke WARNING -- The use of this Standard involves certain hazardous materials, operations and equipment, but does not make recommendations on all safety issues related thereto. Users are responsible for taking appropriate safety and protective measures before using this standard, and ensuring compliance with the conditions stipulated in relevant national regulations. 1 Scope This Standard specifies the method principle, reagents and materials, instruments and equipment, specimen collection, test steps, result calculation and precision for the determination of total sulfur composition in coke by Eschka method, high temperature combustion method, coulometric titration and infrared spectroscopy. This Standard applies to coke and semi-coke (blue charcoal). 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 and expression and judgement of limiting values 3 Eschka method (arbitration method) 3.1 Principle Thoroughly mix the specimen with Eschka reagent. Burn at a certain temperature to convert the sulfur in the specimen into sulfate. The sulfate ions are then allowed to form barium sulfate precipitates. Calculate the total sulfur composition in the specimen based on the mass of barium sulfate. 3.2 Reagents and materials Unless otherwise stated, only reagents confirmed to be analytically pure and distilled or deionized water or water of equivalent purity are used in the analysis. 3.2.1 Magnesium oxide: chemically pure. 3.2.2 Anhydrous sodium carbonate: chemically pure. 3.2.3 Eschka reagent: Weigh 2 portions by mass of magnesium oxide and 1 portion by mass of anhydrous sodium carbonate. Grind until the particle size is less than 0.2 mm. Mix evenly and store in an airtight container. 3.2.4 Hydrogen peroxide: The concentration is 30%. 3.2.5 Hydrochloric acid solution: The density is 1.19 g/cm3. 3.2.6 Nitric acid: The density is 1.42 g/cm3. 3.2.7 Barium chloride solution (100 g/L): Weigh 100 g of barium chloride and dissolve in water. Dilute to 1000 mL with water. 3.2.8 Hydrochloric acid solution (1+1): 1 volume of hydrochloric acid plus 1 volume of water and mix well. 3.2.9 Silver nitrate solution (10 g/L): Weigh 1 g of silver nitrate and dissolve it in water. Dilute to 100 mL with water. Add a few drops of nitric acid, and store in a dark bottle. 3.2.10 Methyl red indicator solution (1 g/L): Weigh 0.1 g of methyl red and dissolve it in 50 mL of ethanol. Dilute to 100 mL with water. 3.2.11 Qualitative filter paper: medium speed; ϕ90 mm~ϕ110 mm. 3.2.12 Quantitative filter paper: medium speed; ϕ90 mm~ϕ110 mm. 3.3 Instruments and equipment 3.3.1 Analytical balance: sensitive to 0.0001 g. 3.3.2 Pallet balance: sensitive to 0.01 g. 3.3.3 Muffle furnace: equipped with temperature control device; can maintain the temperature between 800℃~850℃; the temperature can be adjusted; the furnace can be ventilated. 3.3.4 Desiccator: with built-in color-changing silica gel or granular anhydrous calcium chloride. 3.3.5 Beaker. 3.3.6 Porcelain crucibles: 30 mL and 20 mL. 3.4 Specimen preparation Carry out in accordance with the provisions of GB/T 1997. 3.5 Test steps 3.5.1 Weigh 2 g (accurate to 0.1 g) of Eschka reagent (see 3.2.3) and 1 g (accurate to 0.0001 g) of the specimen with a particle size less than 0.2 mm in a 30 mL porcelain crucible (see 3.3.6). Use nichrome wire to mix evenly. Then cover the specimen with 1 g (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). Gradually increase the furnace temperature to 800℃~850℃ within 1 h ~ 1.5 h. Heat at this temperature for 1 h~1.5 h. 3.5.3 Remove the crucible from the muffle furnace. After cooling to room temperature, use a glass rod to loosen the burning material (if any unburned specimen particles are found, continue burning at 800°C~850°C for 0.5 h). Transfer it to a beaker. Carefully rinse the inside of the crucible with hot water. Add the rinse solution to the beaker. Then add 100 mL~150 mL of hot water. Crush the burning object with a glass rod (if unburned specimen particles are found at this time, the test will be invalid). 3.5.4 Add 1 mL of hydrogen peroxide (see 3.2.4) into the beaker. Heat it to 80℃ and keep it for 30 min. 3.5.5 Filter with qualitative filter paper (see 3.2.11). Rinse the burn onto the filter paper with hot distilled water. Continue to rinse the burned material from the filter paper carefully with hot distilled water. The number of times shall not be less than 10 times. 3.5.6 Boil the filtrate for 2~3 min. Drain excess hydrogen peroxide. Add 2 ~ 3 drops of methyl red indicator solution (see 3.2.10) to the filtrate to indicate whether the elimination is complete. Add hydrochloric acid solution (see 3.2.8) dropwise until the color turns red. Add another 1 mL. Boil for 5 min to remove carbon dioxide. The volume of the solution at this time is approximately 200 mL. 3.5.7 Cover the beaker with a watch glass. Reduce heat until solution stops boiling. Remove the watch glass. Slowly drop 10 mL of barium chloride solution (see 3.2.7) into the hot solution. Stir the solution simultaneously. Cover the watch glass. Keep the solution at a temperature just below the boiling point for 30 min. 3.5.8 After the solution is cooled, filter it with quantitative filter paper (see 3.2.12). Wash with hot water until there is no chloride ion [use silver nitrate solution (see 3.2.9) to check that there is no turbidity]. 3.5.9 Move the precipitate together with the filter paper into a 20 mL porcelain crucible of known mass (see 3.3.6). Ash the filter paper at low temperature first. Then move it into a muffle furnace with a temperature of 800℃~850℃ and burn for 20 min. Take NOTE: You can choose any one of the above two indicator solutions. The mixed indicator solution is valid for 7 days. 4.3 Instruments and equipment 4.3.1 High-temperature tube furnace: heated with silicon carbon rods or silicon carbon tubes, with a temperature control device to maintain the furnace temperature within the range of (1250±10)℃. 4.3.2 Combustion tube: made of high-temperature porcelain, corundum or quartz; the total length of the tube is about 750 mm; one end has an outer diameter of 22 mm, an inner diameter of 19 mm, and a length of about 690 mm; the other end has an outer diameter of 10 mm, an inner diameter of about 7 mm, and a length of about 60 mm. 4.3.3 Combustion boat: made of high-temperature porcelain or corundum; the length is 77 mm, the top width is 12 mm, the bottom width is 9 mm, and the height is 8 mm. 4.3.4 Absorption flask: Erlenmeyer flask, with a volume of 250 mL. 4.3.5 Nickel-chromium wire hook: the diameter is about 2 mm; the length is 650 mm; one end is bent into a small hook. 4.3.6 Silicone rubber tube: the outer diameter 11 mm; the inner diameter 8 mm; the length is approximately 80 mm. 4.3.7 Acid burettes: 25 mL and 10 mL. 4.3.8 Alkali burettes: 25 mL and 10 mL. 4.3.9 Ear wash ball. 4.3.10 Measuring cylinder. 4.3.11 Analytical balance: sensitive to 0.0001 g. 4.4 Specimen preparation Carry out in accordance with the provisions of GB/T 1997. 4.5 Test steps 4.5.1 Test preparation 4.5.1.1 Connect the instruments according to the sequence in Figure 1 for later use. 5.2.3 Combustion boat: bisque or corundum product; the length of the sample loading part is about 60 mm; the temperature resistance is above 1200℃. 5.3 Instruments and equipment 5.3.1 Coulomb sulfur meter: According to the principle of coulomb analysis, the titration process is detected and controlled through double platinum indicator electrodes. Use a microcomputer to control the temperature of the combustion furnace and the test process in real time and perform data processing. Automatically calculate and display the milligrams or mass fraction of sulfur in the specimen. Coulomb sulfur meter mainly consists of the following parts. 5.3.1.1 Combustion furnace: equipped with a temperature measurement and control device, capable of raising the temperature to above 1200°C, and a high-temperature constant temperature zone of at least 70 mm long. The furnace is equipped with a combustion tube with a different diameter that can withstand a temperature of above 1300°C. 5.3.1.2 Sample delivery controller: the specimen can be automatically sent into the combustion tube; the specimen injection speed and stroke can be freely adjusted; the specimen can be flexibly moved forward and backward according to prescribed procedures. 5.3.1.3 Electrolytic cell: the electrolytic cell is divided into two parts: the upper cover and the cell body. The upper cover of the electrolytic cell is fixed with an electrolytic electrode p.......Source: https://www.ChineseStandard.net/PDF.aspx/GBT2286-2017 |