GB/T 2449.1-2021 English PDF (GB/T2449.1-2021)

GB/T 2449.1-2021: Sulphur for industrial use - Part 1: Solid product
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GB/T 2449.1-2021
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 71.060.10
CCS G 13
Replacing 2449.1-2014
Sulphur for industrial use - Part 1.Solid product
ISSUED ON. DECEMBER 31, 2021
IMPLEMENTED ON. JULY 01, 2022
Issued by. State Administration for Market Regulation.
Standardization Administration of PRC.
Table of Contents
Foreword... 3
Introduction... 5
1 Scope... 7
2 Normative references... 7
3 Terms and definitions... 8
4 Technical requirements... 8
4.1 Appearance... 8
4.2 Technical indicators... 8
5 Samples... 8
5.1 Sampling method... 8
5.2 Processing of laboratory sample... 9
5.3 Preparation of specimens... 9
6 Test methods... 10
6.1 General... 10
6.2 Determination of sulfur mass fraction... 10
6.3 Determination of moisture mass fraction... 12
6.4 Determination of ash mass fraction... 14
6.5 Determination of acidity mass fraction... 15
6.6 Determination of mass fraction of organic matter... 17
6.7 Determination of arsenic mass fraction... 24
6.8 Determination of mass fraction of iron... 28
6.9 Determination of mass fraction of powdered sulfur sieve residue... 33
7 Inspection rules... 34
8 Marking, packaging, transportation, storage... 34
9 Safety... 35
Sulphur for industrial use - Part 1.Solid product
Warning. Some reagents used in this document are toxic or corrosive. Some
operations are dangerous. This document does not disclose all possible safety
issues. Users shall strictly follow the relevant provisions for correct use and are
responsible for taking appropriate safety and health measures.
1 Scope
This document specifies the technical requirements, sampling, test methods, inspection
rules, marking, packaging, transportation, storage, safety of solid sulfur for industrial
use.
This document applies to solid industrial sulfur, which is produced from petroleum
refinery gas, natural gas, coal chemical acid gas, coke oven gas, flue gas, sulfur waste
gas recovery, pyrite.
2 Normative references
The contents of the following documents constitute essential provisions of this
document through normative references in the text. Among them, for dated reference
documents, only the version corresponding to the date applies to this document; for
undated reference documents, the latest version (including all amendments) applies to
this document.
GB 190 Packing symbol of dangerous goods
GB/T 601 Chemical reagent - Preparations of reference titration solutions
GB/T 602 Chemical reagent - Preparations of standard solutions for impurity
GB/T 603 Chemical reagent - Preparations of reagent solutions for use in test
methods
GB/T 6003.1-2012 Test sieves - Technical requirements and testing - Part 1.Test
sieves of metal wire cloth
GB/T 6678 General principles for sampling chemical products
GB/T 6679 General rules for sampling solid chemical products
GB/T 6682 Water for analytical laboratory use - Specification and test methods
6.2.2.1 Principle
The sample is eluted with carbon disulfide and weighed. The mass fraction of sulfur in
industrial sulfur is calculated. This method is suitable for the determination of sulfur
mass fraction in high-quality sulfur.
6.2.2.2 Reagents
Carbon disulfide.
6.2.2.3 Instruments and equipment
6.2.2.3.1 Glass sand core crucible. No.3, pore diameter 16 μm ~ 30 μm, volume 30 mL.
6.2.2.3.2 Suction filter bottle. 500 mL.
6.2.2.3.3 Vacuum pump.
6.2.2.3.4 Constant temperature drying oven. The temperature can be controlled from
105 °C to 110 °C.
6.2.2.3.5 Balance. Accurate to 0.001 g.
6.2.2.4 Test procedures
Weigh 2 g ~ 3 g of specimen, accurate to 0.0001 g. Place it in a glass sand core crucible,
that has been dried to constant weight at 105 °C ~ 110 °C.
Connect the air extraction device. In the fume hood, install the glass sand core crucible
containing the sample on the filter bottle. Use a dropper to add an appropriate amount
of carbon disulfide into the crucible. Use a glass rod to stir to dissolve the sulfur. Turn
on the vacuum pump to filter at a suitable rate. Continue washing and dissolving with
carbon disulfide, until most of the sulfur is dissolved. Then use carbon disulfide to wash
the crucible wall and bottom. Conduct suction filter.
Move the glass sand core crucible containing the residue into a constant temperature
drying oven, which has a temperature of 105 °C ~ 110 °C, to dry for 45 minutes. Take
it out and place it in a desiccator, to cool to room temperature. Then use carbon disulfide
to wash the crucible 5 ~ 8 times. Move it into a constant temperature drying oven, which
has a temperature of 105 °C ~ 110 °C, to dry for 30 minutes. Take it out and place it in
a desiccator to cool to room temperature. Then weigh it, accurate to 0.0001 g. Repeat
the above operation with carbon disulfide, until the difference between two consecutive
weighing does not exceed 0.0003 g.
6.2.2.5 Test data processing
The mass fraction of sulfur (ω1) is calculated according to formula (2).
6.6.1.3.3 Barium hydroxide solution. c [1/2 Ba(OH)2] = 0.05 mol/L. Prepare freshly
when using. Add a few drops of phenolphthalein indicator solution to the solution. The
solution needs to be isolated from carbon dioxide in the air with a collection tube filled
with alkali asbestos.
6.6.1.3.4 Hydrogen peroxide solution. 1 + 4.
6.6.1.3.5 Hydrochloric acid standard titration solution. c (HCl) = 0.5 mol/L.
6.6.1.3.6 Hydrochloric acid standard titration solution. c (HCl) = 0.05 mol/L. Measure
50.00 mL of hydrochloric acid standard titration solution (6.6.1.3.5) into a 500 mL
volumetric flask. Use water to dilute to the mark. Shake well. Prepare this solution
before use.
6.6.1.3.7 Sodium hydroxide standard titration solution. c (NaOH) = 0.5 mol/L.
6.6.1.3.8 Sodium hydroxide standard titration solution. c (NaOH) = 0.05 mol/L.
Measure 50.00 mL of sodium hydroxide standard titration solution (6.6.1.3.7) into a
500 mL volumetric flask. Use water to dilute it to the mark. Shake well. Prepare this
solution before use.
6.6.1.3.9 Methyl red-methylene blue mixed indicator solution.
6.6.1.3.10 Phenolphthalein indicator solution. 10 g/L.
6.6.1.3.11 Platinum asbestos. Contain platinum mass fraction of 5% ~ 10%.
6.6.1.3.12 Alkali asbestos.
6.6.1.3.13 Glass wool.
6.6.1.3.14 Oxygen. Pure oxygen, stored in cylinders, equipped with oxygen pressure
reducer.
6.6.1.4 Instruments and equipment
6.6.1.4.1 Porcelain boat. 88 mm × 12 mm.
6.6.1.4.2 Burette. 10 mL, graduation value 0.05 mL.
6.6.1.4.3 Combustion and absorption device. As shown in Figure 1.
As shown in Figure 1, connect the entire device with a short rubber tube.
6.6.1.5.2 Blank test
The tube furnace (F) is heated while oxygen is passed through the device at a flow rate
of approximately 100 mL/min.
When the temperature of the tube furnace F reaches 400 °C ~ 450 °C for about 30
minutes, remove the G5 and G6 scrubbing bottles. Add 20 mL of barium hydroxide
solution, 40 mL of water, 5 mL of hydrogen peroxide solution to each. Then connect
the G5 and G6 scrubbing bottles to the device. These operations shall be performed as
quickly as possible, to avoid absorbing carbon dioxide from the air.
While continuing to pass oxygen through the device at a flow rate of about 100 mL/min,
energize the tube furnace (E), to raise the temperature to 400 °C ~ 450 °C. Maintain
this temperature for about 10 minutes. Then continue to raise the temperature to 800 °C
~ 900 °C. Maintain this temperature for about 30 minutes. Cut off the power supply of
the tube furnace (E). Continue to supply oxygen for about 30 minutes. Then cut off the
power supply of the tube furnace (F).
Remove the G5 and G6 scrubbing bottles. Open the bottle caps. Use a small amount of
water to rinse it. Merge the washing liquid into the absorption liquid. Then perform
blank titrations according to the following steps.
Using phenolphthalein indicator solution as indicator, use hydrochloric acid standard
titration solution (6.6.1.3.6) to titrate the absorption solution to the end point.
Then add 2 ~ 3 drops of methyl red-methylene blue mixed indicator solution to each
scrubbing bottle. Add a certain volume (usually 10.00 mL) of excess hydrochloric acid
standard titration solution (6.6.1.3.6). Shake well. Use sodium hydroxide standard
titration solution (6.6.1.3.8) to make back titration.
The hydrochloric acid standard titration solution (6.6.1.3.6), which is consumed in the
blank test, shall be less than 0.2 mL.
The volume V0 of the hydrochloric acid standard titration solution (6.6.1.3.6), which is
consumed for the blank test of the absorption liquid in the G5 and G6 scrubbing bottles,
is expressed in milliliters (mL), which is calculated according to formula (7).
Where.
V0 - The volume of hydrochloric acid standard titration solution consumed in the
blank test, in milliliters (mL);
V1 - The volume of the hydrochloric acid standard titration solution added, in
milliliters (mL);
V2 - The volume of sodium hydroxide standard titration solution consumed by back
titration, in milliliters (mL).
In the calculation, if the actual concentration of the hydrochloric acid and sodium
hydroxide standard titration solution is not exactly 0.05000 mol/L, V1 and V2 shall be
converted into the volume when the concentration of the hydrochloric acid and sodium
hydroxide standard titration solution is 0.05000 mol/L.
6.6.1.5.3 Specimen weighing and burning
Weigh 1.0 g ~ 1.5 g of specimen in a porcelain boat, accurate to 0.001 g.
The tube furnace (F) is heated and oxygen is passed through the device at a flow rate
of approximately 100 mL/min.
When the temperature of the tube furnace (F) reaches 400 °C ~ 450 °C for about 30
minutes, remove the G5 and G6 scrubbing bottles. Add 20 mL of barium hydroxide
solution, 40 mL of water, 5 mL of hydrogen peroxide solution to each of them, to
oxidize any sulfite which is possibly generated. Then connect the G5 and G6 scrubbing
bottles back to the device. These operations shall be performed as quickly as possible,
to avoid absorbing carbon dioxide from the air.
Send the porcelain boat, which is loaded with the sample, to the unheated part of the
combustion tube (D) in front of the tube furnace E. Immediately introduce oxygen at a
flow rate of 100 mL/min. Heat the tube furnace (E).
When the temperature of tube furnace E reaches 450 °C, maintain this temperature and
no longer rise. Slowly move the tube furnace (E) toward the porcelain boat, to burn the
sulfur, whilst trace amounts of carbonaceous matter remain in the porcelain boat and
combustion tube (D). If the combustion is too intense, the chromium trioxide solution
in the G2 absorption bottle may be drawn back, then the oxygen flow rate shall be
increased to prevent this. If the sulfur sublimates outside the porcelain boat and
condenses between the porcelain boat and the platinum asbestos, the tube furnace (E)
shall be moved to allow complete combustion of the sulfur.
After the sulfur is slowly burned, move the tube furnace (E) to the position where the
porcelain boat is heated. Raise the temperature to 800 °C ~ 900 °C. Heat the combustion
tube (D) and porcelain boat for about 30 minutes, to burn the remaining carbon and
carbonate. break down. Cut off the power supply to the tube furnace (E). Continue to
supply oxygen for about 30 minutes. Blow out the device. Then cut off the power supply
to the tube furnace (F).
6.6.1.5.4 Determination of the amount of carbon dioxide released
When all the carbon dioxide is absorbed (observe whether the precipitation in the G5
used are soaked in 8 mol/L nitric acid for more than 12 hours, rinsed with tap water,
finally rinsed with ultrapure water.
6.7.2 Principle
After the sample is digested by microwave and acid-driven, the pentavalent arsenic in
the test solution is reduced to trivalent arsenic, in the presence of thiourea and ascorbic
acid. After the volume is fixed, the arsenic is transferred to the atomic fluorescence
spectrometer; the trivalent arsenic is reduced to arsenic hydride by using potassium
borohydride, then measured at a wavelength of 193.7 nm. Its fluorescence intensity is
proportional to the arsenic content. It can be compared quantitatively with the standard
solution.
6.7.3 Reagents or materials
6.7.3.1 Nitric acid. Superior grade pure.
6.7.3.2 Hydrochloric acid. Superior grade pure.
6.7.3.3 Hydrochloric acid solution. 5 + 95.It is prepared using high-grade pure
hydrochloric acid or special hydrochloric acid for atomic fluorescence.
6.7.3.4 Potassium borohydride solution (20 g/L).
Weigh 20 g of potassium borohydride. Dissolve it in 1000 mL of sodium hydroxide
solution (5.0 g/L). Prepare this solution immediately before use.
6.7.3.5 Thiourea-ascorbic acid solution. 50 g/L.
Weigh 5 g of thiourea and ascorbic acid respectively into a beaker. Dissolve it using
warm water and dilute to 100 mL.
6.7.3.6 Arsenic (As) standard solution. 0.1 mg/mL.
6.7.3.7 Arsenic (As) standard solution. 1 μg/mL.
Measure 1.00 mL of arsenic standard solution (6.7.3.6). Place it in a 100 mL volumetric
flask. Use water to dilute it to the mark. Shake well. Prepare this solution immediately
before use.
6.7.3.8 Argon gas. Purity above 99.99%.
6.7.4 Instruments and equipment
6.7.4.1 Atomic fluorescence photometer. The detected mass concentration of arsenic
(As) shall not be greater than 0.02 μg/L.
6.7.4.2 Microwave digestion instrument. The power is adjustable, the maximum power
shall not be less than 1200 W; or the temperature is adjustable, the maximum
temperature shall not be less than 200 °C.
6.7.4.3 Electric heating plate. 220 V, 500 W or more.
6.7.4.4 Acid-catching device. The acid-catching device matched with microwave
digestion has adjustable temperature, wherein the maximum temperature shall not be
lower than 150 °C.
6.7.4.5 Evaporation concentrator. Evaporation concentrator matched with microwave
digestion.
6.7.5 Test procedures
6.7.5.1 Preparation of sample solution
Accurately weigh 0.2 g (...