This standard is applicable to the determination of silicon content in ferromolybdenum. Determination range: less than 2.50%. This standard complies with GB 1467-78 "General Principles and General Provisions of Chemical Analysis Methods for Metallurgical Products". GB/T 5059.5-1986 Chemical analysis method for ferromolybdenum - Gravimetric determination of silicon content GB/T5059.5-1986 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Methods for chemical analysis of ferromolybdenum
Gravimetric determination of silicon contentbzxZ.net
Methods for chemical analysis of ferromolybdenumThe gravimetric method for the de termination of sllicon contentThis standard is applicable to the determination of silicon content in ferromolybdenum. The determination range is less than 2.50%. UDC 669.15'28
GB5059.5-86
This standard complies with GB1467-78 "General Principles and General Provisions of Standards for Chemical Analysis Methods of Metallurgical Products". 1 Summary of the method
The sample is decomposed with nitric acid and hydrochloric acid, and white fumes are emitted in a sulfuric acid medium to convert silicon into insoluble silicon dioxide. After separation, it is burned to a constant weight. It is treated with sulfuric acid and hydrochloric acid to remove silicon dioxide, burned and weighed, and the mass of silicon dioxide is obtained from the difference between the two weighings. 2 Reagents
2.1 Hydrofluoric acid (density 1.15).
2.2 Nitric acid (1 +1)
2.3 Hydrochloric acid (density 1.19).
2.4 Hydrochloric acid (1 +4).
2.5 Hydrochloric acid (1+10).
2.B Sulfuric acid (1 +1).
9 Apparatus
8.1 Platinum crucible, capacity 30ml.
3.2 High temperature furnace.
9.3 Dryer.
4 Sample
The sample should pass through a 0.125mm sieve.
5 Analysis steps
5.1 Sample quantity
Weigh 1.0000g of sample.
5.2 Blank test
Carry out a blank test together with the sample.
6.3 Determination
5.3.1 Place the sample (5.1) in a 300ml beaker, add 20ml nitric acid (2.2) and 5ml hydrochloric acid (2.3), cover with a watch glass, slowly heat to decompose, then add 20ml sulfuric acid (2.6), continue heating, and produce thick sulfuric acid white smoke for about 15 minutes, then cool. 5.3.2 Add 50ml hydrochloric acid (2.4), heat to dissolve soluble salts, filter with dense filter paper, use a wiper to move the precipitate attached to the wall of the beaker onto the paper, wash the precipitate and filter paper with warm hydrochloric acid (2.5) until there is no iron dissociation reaction, and then wash with warm water until there is no acidity. Discarded National Bureau of Standards Issued on April 8, 1986
Implementation on August 1, 1987
GB 5069.5—86
Discard the filtrate.
5.9.3 Transfer the precipitate and the filter paper into the platinum glass, slowly heat until the filter paper is incinerated, and then place it in a high-temperature furnace at 1100℃ and burn for 30min. Take it out and cool it slightly, place it in a desiccator, weigh it after cooling it to room temperature, and burn it repeatedly until the weight is constant. 5.8.4 Add 2 to 3 drops of sulfuric acid (2.6) to the crucible (5.3:3), wet the residue, add 5m hydrofluoric acid (2.1), heat it carefully until the white smoke of sulfuric acid is gone, place it in a high-temperature furnace at 1100℃ and burn it for 15min, take it out and cool it slightly, place it in a desiccator and cool it to room temperature, weigh it, and burn it repeatedly until the weight is constant.
6 Calculation of analysis results
Calculate the percentage of silicon according to the following formula!
【(m -m2)-(m;-m)×0.4674
si(%)=-
Wherein: m
-the mass of impure silicon dioxide and platinum crucible measured in (5.3.3), B-the mass of residue and potassium nitrate measured in (5.3.4), 8the mass of impure silicon dioxide and crucible measured in the blank test, 8m
the mass of impurities and platinum crucible measured in the blank test, B1m4
mo——sample size, g!
the conversion factor of silicon dioxide to silicon. 0.4674
the analysis results are expressed to two decimal places. 7Tolerance
The difference in analysis results between laboratories should not be greater than the allowable difference listed in the following table. Silicon content
>1.00 ~2.00
>2.00~2.50
Additional remarks:
This standard is proposed by the Ministry of Metallurgical Industry of the People's Republic of China. ×100
Allowance
This standard is drafted by Jilin Ferroalloy Factory of the Ministry of Metallurgical Industry. From the date of implementation of this standard, the former Ministry of Metallurgical Industry Standard YB580-65 "Molybdenum Ferrochemical Analysis Method" shall be invalid.
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