GB/T 2560-1981 Determination of dropping point of lignite wax

GB/T 2560-1981 Determination of dropping point of montan wax GB/T2560-1981 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Method for determination of dropping point of lignite wax
GB 2560 --- 81
This method is applicable to the determination of dropping point of lignite wax. Key points of the method: The wax sample is placed in the cup of the dropping point meter. The temperature at which the wax sample drips the first drop of wax liquid from the cup or flows out 25 mm of wax liquid under the specified heating conditions is called the dropping point. I. Instruments and Materials
1. Instruments
(1) Dropping point meter: It shall comply with GB514-75 "Technical Requirements for Liquid Thermometers for Petroleum Product Testing", with a metal sleeve and a glass cup, and the edge of the narrow mouth of the cup shall be ground flat. The dropping point thermometer needs to be calibrated in advance; (2) Glass test tube: 40-50 mm in diameter, 180-200 mm in length; (3) Tall beaker: 1000-2000 ml; (4) Stirrer: metal or glass; www.bzxz.net
(5) Electric furnace (with sand tray);
(6) Porcelain crucible: 50 ml;
(7) Glass plate;
(8) Drying oven: capable of maintaining 100-110°C. 2. Materials
Liquid wax or glycerin and other heating media.
II. Determination steps
3. Take about 20 grams of a representative broken wax sample and put it into a porcelain crucible, then put the crucible into a 102-105°C drying oven. After the wax melts, stir occasionally and keep warm for 1 hour, then let it stand at this temperature for at least 30 minutes before use. 4. Place the clean and dry wax cup with narrow mouth flat on a glass plate, then take the prepared wax sample out of the drying oven and immediately and carefully pour it into the wax cup until it is close to the wide mouth surface (the wax sample cannot contain bubbles). When the wax on the edge of the wax cup has just solidified, vertically insert the clean and dry dropping point meter with metal sleeve into the wax cup, so that the edge of the wide mouth of the wax cup fits tightly with the protruding edge inside the sleeve. Be careful not to block the side hole of the metal sleeve 1 with wax. Wait until the indicated temperature of the thermometer drops below 25℃ before measuring the dropping point. 5. Place a round piece of paper at the bottom of the clean and dry glass sleeve, close to the bottom of the tube. 6. Fix the thermometer with the wax cup and wax sample in the glass sleeve with a plug with a central hole and a side cut, so that the axis of the thermometer and the bottom wax tube coincide, and the edge of the narrow mouth of the wax cup and the paper at the bottom of the glass sleeve are 25 mm apart. Use the flame seed glass sleeve on the bracket to fix it in a tall beaker, make it vertical, and make its bottom 10-20 mm away from the bottom of the beaker. Then add the heating medium to the beaker, and the glass sleeve should be immersed in the heating medium for 120-150 mm. 7. The heating medium in the beaker should be heated with a sand bath electric furnace under constant stirring (do not heat it directly with an electric furnace). When the temperature of the dropping point meter reaches 10℃ before the predicted dropping point, control the heating rate to 1-2℃ per minute. 8. Read the temperature immediately when the first drop of wax liquid drips from the fat cup or when the wax flowing out of the fat cup touches the white paper, and use it as the national standard for this wax sample. The Ministry of Coal Industry of the People's Republic of China proposed to implement the dropping point of GB2560-81 on October 1, 1981. Read the decimal place.
9. Take the arithmetic mean of the two parallel determination results as the determination result, and the result shall be rounded to an integer. III. Permits
10. The difference between the parallel determinations shall not exceed the following provisions:
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