GB/T 3816-1983 Determination of asphalt content in lignite wax GB/T3816-1983 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Determination of asphalt in montan wax
Determination of asphalt in montan wax This standard is used to determine the asphalt content in montan wax. UDC 665.44
GB 3816—83
Montan wax Asphalt refers to the part of the substance that is insoluble in isopropanol when the montan wax is extracted with isopropanol solvent at 760mmHg in a boiling state.
Method points: Mix the montan wax sample and quartz sand evenly, put it into a filter paper tube and place it in an extractor, extract it with isopropanol under heating and reflux in a water bath, then remove the solvent and dry it to constant weight. Subtract the weight of the extract from the weight of the sample, and the difference is the measured value of the asphalt content in montan wax (expressed as weight percentage). Then, according to the air pressure (or altitude) at the measurement location, a certain calculation formula is used to convert the content to the equivalent of an air pressure of 760 mmHg (or an altitude of zero). 1 Apparatus, materials and reagents
1.1 Angle flask extractor (see Figure 1), including: ground-mouth triangle flask: 500 ml;
spherical condenser with ground-mouth stopper, used in conjunction with the triangle flask, with two symmetrical small holes at the bottom of the condenser for hooking; filter paper cylinder: 20 mm in diameter, 80 mm in height, see Appendix A (Supplement) for the production method; nickel-chromium wire metal hook.
Condenser
Metal hook
Filter paper tube
Triangular flask
Triangular flask extractor
National Bureau of Standards 1983-08-03 Issued
1983-05-01 Implementation
GB 3816-83
1.2 Electric constant temperature water bath: constant temperature range 37～100℃. 1.3 Electric heating + drying box: can maintain 105～110℃. 1.4 Distiller (see Figure 2), including straight condenser and triangular flask. 1.5 Measuring cylinder: 100ml.
1.6 Universal electric heater: 0～1000W.
Triangular flask: 150ml.
Condenser
Triangular flask
Figure 2 Distiller
Dryer.
Analytical balance: sensitivity 0.0002g.
Plate balance: sensitivity 0.1g.
Barometer.
Quartz sand: chemically pure, particle size 0.45~0.20mm. Isopropyl alcohol (HG3-1167-78): chemically pure, boiling range 81.5~83.5℃. 1.13
1.14 Square medium-speed qualitative filter paper (GB1915-80). 2 Determination steps
2.1 Accurately weigh 1g of wax sample that has been crushed to less than 1mm (weighing to 0.0002g), put it into the filter paper tube containing 10g of quartz sand, and stir it thoroughly with a glass rod.
2.2 Use a nickel-chromium wire hook to hang the filter paper tube on the small hole of the spherical condenser, and then put the condenser into a triangular flask containing 100ml of isopropanol.
2.3 Place the entire extractor in a constant temperature water bath, heat and reflux for extraction, until a colorless solvent drips out of the filter paper tube (usually more than 2 hours are required).
2.4 After the extraction is completed, pour the extract in the 500ml triangular flask into a 150ml triangular flask with a constant weight. Pour 20ml of isopropanol into the 500ml triangular flask and heat it on an electric stove. After the isopropanol liquid boils, remove it, shake it several times to fully wash the adherents on the bottle wall, and then put it back into the electric stove: After heating 2 to 3 times, pour this liquid into the 150ml triangular flask. Repeat the above operation with 20ml of isopropanol liquid. Connect the straight condenser and heat it in a water bath to evaporate the solvent.
2.5 Place the conical flask with the residue in a drying oven and dry it at 102-105℃ for 2h. Take it out and put it in a desiccator. After cooling for 30min, weigh it (accurate to 0.0002g). Dry it for another 30min, cool it and weigh it until the difference between consecutive weighings is no more than 0.0010g.
3 Calculation of results
GB 3816-83
The asphalt content A760° (expressed as weight percentage) in lignite wax at an air pressure of 760mmHg is calculated according to formula (1): 3.1
A0 = Asp (760α)www.bzxz.net
Wherein: a is the air pressure value when measuring asphalt, mmHg; (1
-When the air pressure decreases by 1mmHg from 600 to 760mmHg, the increase in asphalt caused by each 1mmHg decrease in air pressure is 0.05026%. Asp
-The measured value of asphalt when the air pressure is a (mmHg),%. Asp-G-(BA)
× 100
Formula: A
Weight of empty flask, g,
Weight of empty flask and the substance dissolved in isopropanol, g, weight of wax sample, g.
Note: The content of lignite wax in asphalt can also be calculated according to the altitude of the measurement site using the following formula: A%p= Asp - 0.004071H
Wherein: A, — the asphalt content in montan wax at an altitude of zero, %; A\ — the measured asphalt value in montan wax at an altitude of H (m), %; H — the altitude of the measurement site (m)
0.004071 — the maximum increase in the measured asphalt value caused by each increase of 1m in altitude from sea level. 3.2 Take the arithmetic mean of the results of two parallel measurements as the measurement result, and the result shall be rounded to two decimal places. 4 Allowable difference
The difference between parallel measurements shall not exceed the provisions of the following table: Allowable difference (absolute)
Laboratory
Different laboratories
(2)
GB 3816--83
Appendix A
Method for making your own extraction filter paper cartridge
(Supplement)
A.1 Cut a large sheet of qualitative filter paper into 75mm×75mm squares and 50mm×50mm squares, soak them with distilled water, stick them on a clean glass plate, and gently rub the filter paper hairs on the four sides with your fingers. First wrap the large square filter paper on the outer wall of a glass tube with a diameter of 16mm, and then wrap the small square filter paper on the bottom of the glass tube (the bottom of the tube has a small hole). Wrap the two alternately, with 3 layers on the wall and bottom of the tube, and then remove them and place them in a drying oven at 105℃ for drying. Additional notes:
This standard was proposed by the Ministry of Coal Industry of the People's Republic of China and is technically managed by the Beijing Coal Chemistry Institute of the Coal Research Institute. This standard was drafted by the Beijing Coal Chemistry Institute of the Coal Research Institute and the Yunnan Coal Chemical Plant. The main drafters of this standard are Ye Xianbin and Zhao Cuiying. 723
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