GB/T 4700.1-1984 Chemical analysis methods for silicon-calcium alloys - Determination of silicon content by perchloric acid dehydration gravimetric method

GB/T 4700.1-1984 Chemical analysis methods for silicon-calcium alloys - Determination of silicon content by gravimetric method with perchloric acid dehydration GB/T4700.1-1984 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Chemical analysis method of calcium-silicon alloy
Perchloric acid dehydration -gravimetric method for the determination of silicon content
This standard is applicable to the determination of calcium-silicon alloy content. Determination range: ≤ 50.00%. This standard complies with GB1467-78 "General principles and general practice of chemical analysis method standards for metallurgical products",
1 Summary of methods
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5\891543
21:546.28
GB 4700.1--84
Mix the test mud and add acid and high-purity acid fume, heat and ignite to generate non-degradable silica. After flame burning, weigh the part, add hydrofluoric acid, make a dichromatic reaction, and then calculate the silica content based on the difference in the cracks before and after the treatment with oxyacetic acid. 2.1
Oxygen plate (specific gravity 1.15)
2.3 Lactic acid (specific gravity 1.67)
Hydrochloric acid (specific gravity 1.19)
Acid (1).
Acid (1+2).
2.T Acid (1·10).
Thiocyanate (1*3)
Thiamine forging solution (5).
3 Sample
Test sample 0,125mm Nm
4.1 Sample
Take out the 2000g test piece.
4.2 Air test
Prepare the test piece with the wet sample.
4.3 Determination
1.3.1 Place the test piece (4.1) in a nickel crucible containing 5g of the mixture (2.1), stir for about 1g, and then cover with 1g of the mixture. Flux (2.1), light" low quality culture Qi and then gradually increase the temperature, and finally melt at 700 ~ 750 "until the sample is completely melted. .3.2 Add to a 1510ml beaker and place it in a cold place. Add 60ml hydrochloric acid (2.6) on the surface. After the bad blocks are released, take out the sweet disease and clean it with water: add 40ml high efficiency acid (2.3), and generate a flow in the hot purple full high oxygen steam tower cup. Then follow the National Bureau of Standards 1984-1 0 0 4 issued
198509-01 implementation
GB 4700.1—84
Continue heating for about 15 minutes.
4.3.3 Remove the beaker and let it cool. Add 20ml hydrochloric acid (2.5) and 100ml warm water. Stir until all the salts are completely dissolved. Then filter the precipitate and filter paper with filter paper pulp in a 500ml beaker. Wash the precipitate and filter paper with hot hydrochloric acid (2.7) for 5 times, and then with warm water until there is no iron ion reaction (test with ammonium thiocarbate solution (2.9)). Keep the filter paper. 4.3.4 Add 10 ml of perfluoric acid (2.3) to the filtrate and washing liquid, heat and evaporate until the micro-gas of perfluoric acid flows throughout the beaker, and continue heating for 15 minutes. The following is carried out according to 4.3.3. 4.3.5 Place the precipitate obtained in 4.3.3 and 4.3.4 together with the filter paper in a glass, first ash at low temperature, then burn at 1100℃, cool slightly and place in a desiccator to cool, weigh and burn repeatedly to constant weight (m2). 4.3.6 Add 1~2 ml of water along the glass wall to moisten the residue, add 4.~5 drops of sulfuric acid (2.8) and 5 ml of hydrofluoric acid (2.2), place the meter on the glass and slowly incubate until all the trihydrogen sulfide fumes are gone. Then heat at 11℃ and burn repeatedly to constant weight, cool in a desiccator and weigh (m2).
5 Calculation of analysis results
The percentage of the calculated results shall be as follows:
si(%)-
[(m:mz)-(ms-mg))x0.4G74
Wherein: m:
"The maximum mass of the precipitate and pellet before hydrofluoric acid treatment, m?--The mass of the residual mass of the blank test pellet and pellet after hydrofluoric acid treatment, g; The mass of the residual mass of the blank test pellet and pellet after hydrofluoric acid treatment, g;
\-The mass of the sample, g1
Silicon oxide is converted to silicon dioxide,
Analysis The results are expressed to two decimal places. 6 Allowable deviation
The difference between the analysis results of the experimental case shall not exceed the allowable deviation listed below. X100
Additional remarks:
This standard is proposed by the Ministry of Metallurgy of the People's Republic of China. This standard is drafted by the Ministry of Iron and Steel Corporation of China. u.6n
From the date of implementation of this standard, the source metallurgical standard YB579-65 "Silicon calcium alloying ion analysis method" is used as a support.
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