This standard is applicable to the determination of sulfur content in ferromolybdenum. Determination range: 0.015% to 0.250%. This standard complies with GB 1467-78 "General Principles and General Provisions of Chemical Analysis Methods for Metallurgical Products". GB/T 5059.9-1988 Chemical analysis method for ferromolybdenum - Determination of sulfur content by infrared absorption method GB/T5059.9-1988 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Methods for chemical anelysis of ferromolybdenum
Determination of sulfur content by infrared absorption method
Methods for chemical anelysis of ferromolybdenumThe infrared absorption method for thedetermination of sulfur contentThis standard is applicable to the determination of sulfur content in ferromolybdenum. Determination range: 0.015%~0.250%. UDC 669. 15'28
GB5059.9—88
This standard complies with GB1467-78 "General Principles and General Provisions for Chemical Analysis Methods of Metallurgical Products". 1 Method Summary
The sample is heated and burned in the oxygen flow of a high-frequency induction furnace. The generated sulfur dioxide is carried by the oxygen to the measuring chamber of the infrared analyzer. The sulfur dioxide absorbs infrared energy of a specific wavelength. The absorbed energy is proportional to the sulfur dioxide concentration. The sulfur content can be measured according to the change in the energy received by the detector.
2 Reagents and Materials
Magnesium Perchlorate: Anhydrous, Granular.
Caustic Soda Asbestos: Granular.
2.3 Glass Wool.
Tungsten Granules: Sulfur content less than 0.0002%, particle size 0.8~1.4mm. 2.5
Tin Granules: Sulfur content less than 0.0003%, particle size 0.4~0.8mm. 2.6
Pure Iron: Purity greater than 99.8%, sulfur content less than 0.002%, particle size 0.8~~1.68mm. 2.7
Oxygen: Purity greater than 99.95%, other grades of oxygen can also be used if a low and consistent blank can be obtained. Power Gas Source: Nitrogen or compressed air, with impurities (water and oil) less than 0.5%. 2.8
Quality crucible: Φ×h, mm: 23×23 or 25×25, and burn in a high temperature heating furnace above 1200℃ for 4h or burn in oxygen until the blank value is the lowest. wwW.bzxz.Net
2.10 Crucible tongs.
3 Instruments and equipment
3.1 Infrared absorption sulfur analyzer (sensitivity is 1.0ppm) The device is shown in the figure.
Approved by the Ministry of Metallurgical Industry of the People's Republic of China on February 2, 1988 and implemented on March 1, 1989
GB 5059.9-88
1-Oxygen cylinder, 2-two-stage pressure regulator; 3-gas washing bottle, 4, 9-drying tube; 5-pressure regulator, 6-high-frequency induction furnace; 7-combustion tube; 8-dust collector; 10-flow controller, 11-sulfur dioxide infrared detector 3.1.1 Gas washing bottle (3): Contains caustic soda asbestos (2.2). 3.1.2 Drying tube (4, 9): Contains magnesium perfluoride (2.1). 3.2 Gas source
3.2.1 The carrier gas system includes an oxygen container, a two-stage pressure regulator and a timing control part to ensure the provision of appropriate pressure and rated flow. 3.2.2 The power gas source system includes power gas (fluorine gas or compressed air), a two-stage pressure regulator and a timing control part to ensure the provision of appropriate pressure and rated flow.
3.3 The high-frequency induction furnace
should meet the requirements of the melting temperature of the sample.
3.4 ​​Control system
3.4.1 The microprocessor system includes a central processing unit, a memory, a keyboard input device, an information center display screen, an analysis result display screen and an analysis result printer.
3.4.2 The control functions include automatic loading and unloading of crucibles and furnace lifting, automatic cleaning, analysis condition selection and setting, monitoring of the analysis process and alarm interruption, analysis data collection, calculation, correction and processing, etc. 3.5 Measurement system
It is mainly composed of an electronic balance (sensitivity not greater than 1.0mg) controlled by a microprocessor, an infrared analyzer and electronic measuring elements. 4 Samples
All samples should pass through a 0.125mm sieve.
5 Analysis steps
5.1 Sample volume
Weigh 0.800~1.000g sample.
5.2 Blank test
Weigh 1.000g pure iron standard sample with sulfur content less than 20ppm and place it in (2.9) pre-filled with 0.300±0.005g tin particles (2.5), covering 1.500±0.005g tungsten particles (2.4), and measure according to 5.5 in the same range or channel. Repeat enough times until a low and relatively consistent reading is obtained (the blank value should be equal to the difference between the measured sulfur content and the known sulfur content of the standard sample). Record at least three readings, calculate the average blank value, and enter the blank value into the analyzer with reference to the instrument manual. The instrument will then perform electronic compensation for the blank value during measurement. 5.3 Analysis preparation
5.3.1 Debug and check the instrument according to the instrument manual to ensure that the instrument is in a normal and stable state. 268
5.3.2 Select and set the best analysis conditions.
GB5059.9—88
5.3.3 Use standard samples and flux to make two test tests according to 5.5 to determine whether the instrument is normal. 5.3.4 Weigh several portions of 0.500g of standard samples (or pure iron standard samples) with a sulfur content of about 0.0025%, and measure according to 5.5. The result fluctuation should be within the range of ±0.0003%, otherwise the instrument sensitivity should be adjusted according to the instrument requirements. 5.4 Calibration test
5.4.1 According to the sulfur content of the sample to be tested, select the corresponding range or channel, and select three standard samples of the same type (the content of the sample to be tested should fall within the sulfur content range of the selected three standard samples), and calibrate them in turn. The fluctuation of the results should be within the allowable error range to confirm the linearity of the system, otherwise the linearity of the system should be adjusted according to the instrument manual. 5.4.2 For different ranges or channels, their blank values ​​should be measured and calibrated respectively. 5.4.3 When the analysis conditions change, such as when the instrument has not been preheated for 1 hour, the oxygen source, or the flux blank value has changed, it is required to re-measure the blank and calibrate.
5.5 Determination
5.5.1 According to the sulfur content range of the sample to be tested, select the best analysis conditions of the instrument: such as the combustion integration time of the instrument, the setting of the comparison level (or set number), etc.
5.5.2 Place the sample (5.1) in (2.9) which has been pre-filled with 0.300g of tin particles (2.5), cover it with 1.50g of tungsten particles (2.4), take the crucible with tongs and place it on the crucible seat of the furnace, operate according to the instrument manual, start analysis and read the results. 6
Allowable difference
The difference in analysis results between laboratories should not be greater than the allowable difference listed in the following table. %
0. 015~0. 025
0. 025--0. 045
>0.045~0. 070
>0.070～~0.120
0. 120~0. 250
Additional remarks:
This standard was drafted by Jilin Ferroalloy Factory.
The main drafter of this standard is Chang Yanfu.
Allowable difference
From the date of implementation of this standard, the former Ministry of Metallurgical Industry Standard YB580-65 "Chemical Analysis Method of Ferromolybdenum" will be invalid. 269
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