GB/T 5195.9-1985 Chemical analysis method of fluorspar - Determination of silicon dioxide content by hydrofluoric acid gravimetric method GB/T5195.9-1985 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Chemical analysis method of fluorspar
Determination of silicon dioxide content by hydrofluoric acid gravimetric method
This standard is applicable to the determination of silicon dioxide content in fluorspar. Determination range: 1.50～35.00%. This standard complies with GB146778 "General Principles and General Provisions of Standards for Chemical Analysis Methods of Metallurgical Products". 1 Summary of the method
UDC 549.454
: 546.28 - 31
GB 5195.9-85
The sample is decomposed with dilute acetic acid to separate calcium carbonate. The residue is treated with hydrofluoric acid. Silicon dioxide is converted into silicon tetrafluoride and volatilized. The white content of silicon dioxide is calculated based on the mass difference before and after the hydrofluoric acid treatment. 2 Reagents
2.1 Hydrofluoric acid (specific gravity 1.15).
2.2 Acetic acid (10%).
2.3 Ammonium hydroxide (1+1).
3 Sample
3.1 The sample should pass through a 240 mesh.
3.2 The sample should be dried at 105±1℃+ for 2h in advance, placed in a desiccator, and cooled to room temperature. 4 Analysis steps
4.1 Determination of number of mice
Three samples should be weighed for determination during analysis, and the average value should be taken. 4.2 Sample quantity
Weigh 0.2500g of sample.
4.3 Determination
4.3.1 Place the sample (4.2) in a 150ml beaker, add 10ml acetic acid (2.2), mix, cover with a gauge, leave for 30min, shake once every 10min, then filter with slow quantitative filter paper, wipe off the precipitate attached to the beaker wall with a wiper, wash the beaker with water and wash the precipitate 4 to 5 times.
4.3.2 Place the precipitate together with the filter paper in a clean platinum crucible, first ash at low temperature, then move to a high temperature furnace, burn at 650℃ for 30min, take out, cool slightly, place in a desiccator, weigh after cooling to room temperature, and repeat burning until constant weight (m). 4.3.3 Wet the residue in the platinum crucible with a small amount of water, add 5ml hydrofluoric acid (2.1), evaporate at low temperature to 10: remove and cool, then add 2-3ml hydrofluoric acid (2.1) (if the silicon content is high, repeat for 10 times), evaporate until nearly 10: 20, remove and cool, drop III ammonium hydroxide (2.3) to slightly alkaline, and evaporate at low temperature to dryness. Place in a high-temperature furnace and burn at 650℃ for 20min, take out, cool slightly, and place in a desiccator. After cooling to room temperature, weigh and repeat burning to constant weight (㎡2). Issued by the National Bureau of Standards on May 18, 1985
Implemented in March 1986bzxz.net
5 Calculation of analysis results
Calculate the percentage of silicon oxide according to the following formula: GB5195.9-85
Sio2 (%)
Where: mi-
Mass of the residue after ashing and the platinum crucible, m; ml-m2
Mass of the residue after hydrofluoric acid treatment and the platinum crucible, g; m. Sample size, g.
6 Allowable difference
The difference in analysis results between laboratories should not be greater than the allowable difference listed in the following table. Silicon dioxide content
1.50 ~2.00
2.00~3.00
3.00 ~5.00
5.00 ~ 10.00
10.00 ~ 20.00
20.00~35.00
Additional remarks:
This standard is proposed by China Nonferrous Metals Industry Corporation. This standard is drafted by Zhejiang Province Fluorite Mining Company. This standard is drafted by Zhejiang Metallurgical Research Institute. This standard is mainly drafted by Tang Jinhui.
Allowable deviation
From the date of implementation of this standard, the former Ministry of Metallurgical Industry Standard YB322-65 "Chemical Analysis Method of Fluorite" shall be invalidated.
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