GB/T 2559-1981 Determination of melting point of montan wax GB/T2559-1981 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Method for determination of melting point of lignite wax
This method is applicable to the determination of melting point of lignite wax. GB 2559 -
Method Key Points: Place the open capillary tube containing the wax sample into the melting point determination tube water bath and heat it at a certain heating rate. The temperature when the wax column just starts to rise is taken as the melting point of the wax sample. Apparatus
1. Apparatus
(1) Melting point determination tube (see figure)
(2) Porcelain crucible: 50 ml;
(3) Drying box: capable of maintaining 100-110℃; (4) Electric furnace (0-500 watts) or small Bunsen burner; Apparatus bZxz.net
(5) Mercury thermometer: 50-100℃, graduation of 0.1℃ (should be calibrated in advance); (6) Capillary: inner diameter of about 0.8-1.2 mm, length of about 7 0 mm, the tube wall thickness is 0.2-0.3 mm, and both ends are open; (7) Blade.
2. Determination steps
2. Take about 20 grams of representative broken wax sample and put it into a porcelain crucible, then put the crucible into a drying oven at 102-105°C. After the wax melts, stir it occasionally and keep it warm for 1 hour, then let it stand at this temperature for at least 30 minutes. 3. Vertically immerse one end of the cleaned and dried capillary tube into the molten wax sample to a depth of about 10 mm, then take it out, and after it solidifies, use a blade to scrape off the wax adhering to the outside of the capillary tube (there should be no bubbles in the wax column). The wax column at the mouth of the tube should be flattened and placed at room temperature for more than 12 hours or in ice water (0°C). ) and cool for 10 minutes before the measurement. 4. Pour the distilled water that has just been boiled and cooled into the melting point tube, so that the liquid level is about 15 mm above the branch tube mouth, and then fix the melting point tube on the bracket.
5. Tie the upper part of the capillary tube containing the wax sample to the mercury thermometer with a rubber band, so that the wax column in the capillary tube is close to the side of the mercury ball of the thermometer, and tie it to the upper plane of the wax column with a thin rubber band to facilitate the observation of the rise of the wax column. 6. Use a rubber stopper with a hole to fix the thermometer in the melting point tube. The mercury ball of the thermometer should be about 15 mm below the branch tube mouth of the melting point tube (as shown in the figure).
7. Heat the capillary tube with an electric furnace or a small Bunsen burner. For the hot melting point measuring tube, when it is about 10℃ away from the predicted melting point, increase the temperature at a rate of about 1℃ per minute, and observe the temperature when the wax column just starts to rise, which is the melting point of the wax sample. Read to two decimal places. 8. Take the arithmetic mean of the results of two parallel measurements as the measurement result. The result is rounded to one decimal place. III. Permission
9. The difference between parallel measurements shall not exceed the following provisions: Issued by the General Administration of Standards of the People's Republic of China
Proposed by the Ministry of Coal Industry of the People's Republic of China
Implemented on October 1, 1981
Shanxi Coal Chemistry Institute of the Chinese Academy of Sciences
Beijing Coal Chemistry Institute of Coal Research Institute
GB 2559—81
-Thermometer
Capillary
Rubber band
Rubber band
Capillary melting point measuring device
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