GB/T 5686.7-1988 Chemical analysis methods for manganese silicon alloys - Determination of sulfur content by infrared absorption method

GB/T 5686.7-1988 Chemical analysis method for manganese silicon alloys - Determination of sulfur content by infrared absorption method GB/T5686.7-1988 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Chemical analysis method of silicomanganese alloy
Determination of sulfur content by infrared absorption method
Methods for chemical analysis of silicomanganese alloyThe infrared absorption method for thedetermination of sulfur contentThis standard is applicable to the determination of sulfur content in silicomanganese alloy. Determination range: 0.005%～0.045%. UDC 669.74' 782
GB5686.788
This standard complies with GB1467-78 "General Principles and General Provisions of Standards 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 oxygen to the measuring chamber of the infrared analyzer. Sulfur dioxide absorbs infrared energy of a specific wavelength. Its absorption 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 materialswww.bzxz.net
Magnesium perfluorate: anhydrous, granular.
2.2 Caustic soda asbestos: granular.
2.3 Glass wool.
2.4 Tungsten particles: sulfur content less than 0.0002%, particle size 0.8~~1.4mm. 2.5 Tin particles: sulfur content less than 0.0003%, particle size 0.4~～0.8mm. 2.6 Pure iron: purity greater than 99.80%, 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 D.5%. 2.8
2.9 Crucible: medium × h, mm: 23×23 or 25×25, and burn in a high temperature furnace above 1200℃ for 1 hour or burn with oxygen until the blank value is the lowest.
2.10 Clamps.
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 311
Implemented on March 1, 1989
GB 5686.7-88
1:-Oxygen cylinder: 2-two-stage pressure regulator; 3-gas washing bottle, 1.9-drying tube; 5-pressure regulator; 6-high-value 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 perchlorate (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 (nitrogen 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
3.4.7 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 the crucible and lifting of the furnace, automatic cleaning, analysis condition selection and setting, monitoring of the analysis process and alarm interruption, collection, calculation, correction and processing of analysis data, 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. A sample
All samples should pass through a 0.125mm sieve.
5 Analysis steps
5.1 Sample volume
Weigh 0.200 g of sample.
5.2 Blank test
Weigh 0.500 g of pure iron standard sample with sulfur content less than 20 ppm, place it in a crucible (2.9) pre-filled with 0.300±0.005 g of tin particles (2.5), cover it with 1.500±0.005 g of tungsten particles (2.4), and measure it according to 5.5 in the same range or channel, and repeat it a sufficient number of 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 perform electronic compensation for the blank value when measuring the sample.
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. 81
5.3.2 Select and set the best analysis conditions.
GB5686.7--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 0.500g of standard sample (or pure iron standard sample) with a sulfur content of about 0.0025%, and measure it 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, and the oxygen source, crucible or 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 a crucible (2.9) pre-filled with 0.30g 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 furnace platform, 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. 005 ~0. 015
≥0.015~0.025
≥0. 025 ~ 0. 045
Additional remarks:
This standard was drafted by Xinyu Iron and Steel Plant.
The main drafters of this standard are You Shen and Liu Jinhua.
From the date of implementation of this standard, the former Ministry of Metallurgical Industry Standard YB79--65 "Chemical Analysis Method of Manganese Silicon Alloy" will be invalid. 316
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