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GB/T 5686.7-2008 PDF in English


GB/T 5686.7-2008 (GB/T5686.7-2008, GBT 5686.7-2008, GBT5686.7-2008)
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GB/T 5686.7-2008English150 Add to Cart 0-9 seconds. Auto-delivery. Ferromanganese, ferromanganese-silicon, nitrogen-bearing ferromanganese and manganese metal -- Determination of sulfur content -- Infrared absorption method and combustion-neutralization method Obsolete
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GB/T 5686.7-2008: PDF in English (GBT 5686.7-2008)

GB/T 5686.7-2008
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.100
H 11
Replacing GB/T 5686.7 ~ 5686.7-1988, GB/T 7730.8-2000
GB/T 7730.9-1988, GB/T 8654.10 ~ 8654.11-1988
Ferromanganese, ferromanganese-silicon, nitrogen-
bearing ferromanganese and manganese metal -
Determination of sulfur content - Infrared absorption
method and combustion-neutralization method
ISSUED ON: MAY 13, 2008
IMPLEMENTED ON: NOVEMBER 01, 2008
Issued by: General Administration of Quality Supervision Inspection and
Quarantine of PRC;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3 
1 Scope ... 5 
2 Normative references ... 5 
3 Method 1: Infrared absorption method ... 6 
4 Method 2: Combustion-neutralization method ... 9 
5 Test report ... 15 
Ferromanganese, ferromanganese-silicon, nitrogen-
bearing ferromanganese and manganese metal -
Determination of sulfur content - Infrared absorption
method and combustion-neutralization method
Warning: The personnel using this part shall have practical experience in
formal laboratory work. This part does not point out all possible safety
issues. The user is responsible for taking appropriate safety and health
measures and ensuring compliance with the conditions stipulated by
relevant national laws and regulations.
1 Scope
This part specifies the infrared absorption method and combustion-
neutralization method to determine the sulfur content in ferromanganese-silicon,
ferromanganese, blast furnace ferromanganese, nitrogen-bearing
ferromanganese, manganese metal, electrolytic manganese metal.
This part applies to the determination of sulfur in manganese-silicon alloy,
ferromanganese, blast furnace ferromanganese, nitrogen-bearing
ferromanganese, manganese metal, electrolytic manganese metal. The
infrared absorption method is suitable for the determination of sulfur content
(mass fraction) of 0.005% ~ 0.120% in manganese-silicon alloy,
ferromanganese, blast furnace ferromanganese, nitrogen-bearing
ferromanganese, manganese metal, electrolytic manganese metal. The
combustion-neutralization method is suitable for the determination of the sulfur
content (mass fraction) of 0.015% ~ 0.120% in manganese-silicon alloy,
ferromanganese (including blast furnace ferromanganese), manganese metal,
electrolytic manganese metal.
2 Normative references
The provisions in following documents become the provisions of this Standard
through reference in this Standard. For the dated references, the subsequent
amendments (excluding corrections) or revisions do not apply to this Standard;
however, parties who reach an agreement based on this Standard are
encouraged to study if the latest versions of these documents are applicable.
For undated references, the latest edition of the referenced document applies.
GB/T 4010 Ferroalloys - Sampling and preparation of samples for chemical
analysis
3 Method 1: Infrared absorption method
3.1 Principle
The sample is heated and burned in the oxygen stream 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 certain wavelength; its absorption energy is proportional to its
concentration. According to the change of energy received by the detector, it
can measure the sulfur content.
3.2 Reagents and materials
3.2.1 Acetone, the residual sulfur content after evaporation is less than
0.0005%.
3.2.2 Magnesium perchlorate, anhydrous, granular.
3.2.3 Caustic soda asbestos, granular.
3.2.4 Glass wool.
3.2.5 Tungsten particles: the sulfur content is less than 0.0002% and the
particle size is 0.8 mm ~ 1.4 mm.
3.2.6 Tin particles: the sulfur content is less than 0.0003% and the particle size
is 0.4 mm ~ 0.8 mm. If necessary, use acetone (3.2.1) to clean the surface.
3.2.7 Oxygen, the purity is greater than 99.95%; if other grades of oxygen can
obtain a low and consistent blank, it can also be used.
3.2.8 Power gas source: nitrogen or compressed air, the impurity (water and oil)
content of which is less than 0.5%.
3.2.9 Crucible: diameter x height 23 mm x 23 mm or 25 mm x 25 mm; burned
in a high-temperature heating furnace higher than 1200 °C for 4 h or oxygen
burning to the lowest blank value.
3.2.10 Crucible tongs.
3.3 Instrument
3.3.1 Infrared absorption sulfur analyzer (sensitivity of 0.1 × 10-6), the device is
as shown in Figure 1.
combustion tube at 1400 °C for 5 min in advance and cooled for later use.
4.2.4 Flux: tin particles, pure iron, vanadium pentoxide, etc. The sulfur content
in the flux shall be less than 0.001%.
4.2.5 Silica gel, activated alumina or magnesium perchlorate.
4.2.6 Soda lime or sodium hydroxide, granular.
4.2.7 Sulfuric acid solution saturated with chromic acid: add potassium
dichromate or chromic anhydride to sulfuric acid (ρ1.84 g/mL) to saturation; use
the supernatant.
4.2.8 Absorbent solution: pipette 3.5 mL of hydrogen peroxide (ρ1.10 g/mL);
use water to dilute it to 1000 mL; mix it uniformly.
4.2.9 Mix indicator: weigh 0.1250 g of methyl red and 0.0860 g of methine blue;
use absolute ethanol to dissolve and dilute it to 100 mL; mix it uniformly.
4.2.10 Sulfamic acid standard solution
Weigh 0.1000 g of sulfamic acid (NH2SO3H) which has a purity greater than
99.90%, dried in advance in a vacuum sulfuric acid dryer for about 48 hours,
into a 300 mL beaker; add 30 mL of water to completely dissolve it; transfer it
into a 500 mL brown volumetric flask. Use water to dilute it to the mark. Mix it
uniformly.
4.2.11 Standard titration solution of sodium hydroxide, c(NaOH) = 0.05 mol/L.
4.2.11.1 Preparation: Weigh 0.2000 g of sodium hydroxide and dissolve it in
1000 mL water; add 1 mL of newly prepared saturated solution of barium
hydroxide; mix well; isolate carbon dioxide and place for 2 d ~ 3 d; take the
supernatant from the upper part when using it.
4.2.11.2 Calibration: Pipette 20.00 mL of sulfamic acid standard solution
(4.2.10); put it in a 250 mL conical flask; add 100 mL of water and 10 drops of
bromothymol blue indicator (1 g/L); immediately use the sodium hydroxide
standard titration solution (4.2.11.1) to titrate it, until the solution turns from
yellow to pure blue and keeps the color unchanged for 30 seconds, which is
used as the end point.
Use 120 mL water to do a blank test from the addition of 10 drops of
bromothymol blue indicator (1 g/L) in 4.2.11.2.
4.2.11.3 Calculation: Calculate the concentration of sodium hydroxide standard
titration solution according to formula (1):
Medium-and-low-carbon ferromanganese -
High-carbon, blast furnace ferromanganese 1.00 g of tin particles + 0.25 g of pure iron
Manganese metal -
4.5.2 Blank test
Do a blank test with the sample.
4.5.3 Preparation for analysis
4.5.3.1 Connect each part of the sulfur determination device and check the air
tightness. Heat the high-temperature combustion tube (12) to increase the
temperature in the tube to 1400 °C ~ 1450 °C.
4.5.3.2 Pipette 40 mL of absorption solution (4.2.8) into the absorption bottle
(16). Add 5 drops of mixed indicator (4.2.9). At a flow rate of 700 mL/min ~ 900
mL/min, lead in oxygen for about 5 min, to drive off the carbon dioxide in the
solution. If the solution is reddish purple at this time, add sodium hydroxide
standard titration solution (4.2.11), until the solution is bright green.
4.5.4 Determination
4.5.4.1 Place the sample (4.5.1) in the porcelain boat (4.2.3). Push it into the
central high-temperature part of the high-temperature combustion tube (12.
Immediately add the silicone plug (14). Pay special attention to sealing. Let in
oxygen slightly to prevent the absorption liquid from flowing back.
4.5.4.2 Applicable to manganese-silicon: Lead in oxygen at a flow rate of 200
mL/min to burn the sample for 3 min. Then lead the oxygen at a flow rate (inlet
flow rate) of 700 mL/min ~ 900 mL/min into the absorption bottle (16), so that
sulfur dioxide is absorbed. After burning for 10 minutes, use the sodium
hydroxide standard titration solution (4.2.11) to titrate the solution from red
purple to bright green; then use the two-way piston (9) to control the intermittent
oxygen supply at a flow rate of 1000 mL/min ~ 1200 mL/min for 5 min. If the
solution is reddish purple, continue using sodium hydroxide standard titration
solution (4.2.11) to titrate it to bright green. Stop leading in oxygen. Use the
above-mentioned absorption solution wo wash the drying tube (15) and the
connecting part of the tube. Lead it into the absorption bottle. If the solution is
reddish purple, continue using the sodium hydroxide standard titration solution
(4.2.11) to titrate it, until it is bright green, which is used as the end point.
Applicable to ferromanganese: Lead in oxygen at a flow rate of 200 mL/min to
burn the sample for 5 min. Then lead the oxygen at a flow rate (inlet flow rate)
of 700 mL/min ~ 900 mL/min into the absorption bottle (16), so that sulfur
dioxide is absorbed. After burning for 10 minutes, use the sodium hydroxide
standard titration solution (4.2.11) to titrate the solution from red purple to bright
green; then use the two-way piston (9) to control the intermittent oxygen supply
at a flow rate of 1000 mL/min ~ 1200 mL/min for 5 min. If the solution is reddish
purple, continue using sodium hydroxide standard titration solution (4.2.11) to
titrate it to bright green. Stop leading in oxygen. Use the above-mentioned
absorption solution wo wash the drying tube (15) and the connecting part of the
tube. Lead it into the absorption bottle. If the solution is reddish purple, continue
using the sodium hydroxide standard titration solution (4.2.11) to titrate it, until
it is bright green, which is used as the end point.
Applicable to manganese metal: Immediately introduce the oxygen at a flow
rate (inlet flow rate) of 700 mL/min ~ 900 mL/min into the absorption bottle (16)
to absorb the sulfur dioxide. After burning for 10 minutes, use the sodium
hydroxide standard titration solution (4.2.11) to titrate the solution from red
purple to bright green; then use the two-way piston (9) to control the intermittent
oxygen supply at a flow rate of 1000 mL/min ~ 1200 mL/min for 5 min. If the
solution is reddish purple, continue using sodium hydroxide standard titration
solution (4.2.11) to titrate it to bright green. Stop leading in oxygen. Use the
above-mentioned absorption solution wo wash the drying tube (15) and the
connecting part of the tube. Lead it into the absorption bottle. If the solution is
reddish purple, continue using the sodium hydroxide standard titration solution
(4.2.11) to titrate it, until it is bright green, which is used as the end point.
4.5.5 Result calculation
Calculate the sulfur content (mass fraction) in the sample according to formula
(2):
Where:
c - The concentration of sodium hydroxide standard titration solution, in
moles per liter (mol/L);
V1 - The volume of sodium hydroxide standard titration solution consumed
when titrating the sample solution, in milliliters (mL);
V2 - The volume of sodium hydroxide standard titration solution consumed
when titrating the blank solution, in milliliters (mL);
m - The mass of sample, in grams (g);
0.01603 - The molar mass of sulfur equivalent to 1.00 mL of 1.000 mol/L
sodium hydroxide standard titration solution, in grams per mole (g/mol).
4.6 Allowable difference
......
 
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.