Some standard content:
National Standard of the People's Republic of China
Sodium hydroxide for industrial use
Sodium hydroxide for industrial useGB209—93
Replaces GB209—84
This standard refers to The international standard ISO5992--1979 "Determination of Sodium Hydroxide-Mercury Content for Industrial Use by Disulfide Photometry" is adopted. 1 Subject content and scope of application
This standard specifies the technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of industrial sodium hydroxide. This standard applies to sodium hydroxide produced by the mercury method, diaphragm method, and causticization method. 2 Reference standards
Preparation of standard solutions for titration analysis (volume analysis) of chemical reagents GB601
Preparation of preparations and products used in chemical reagent test methods GB603
GB4348.1||tt ||Determination of sodium hydroxide and sodium carbonate content in industrial sodium hydroxide Determination of sodium chloride content in industrial sodium hydroxide Mercury content method GB4348.2
GB4348.3 Iron content in industrial sodium hydroxide Determination of phenanthroline Photometric method GB7698 Determination of carbonate content in sodium hydroxide for industrial use Titration method GB11213.1
GB11213.4
3 Technical requirements
Hydrogen for chemical fibers Determination method of sodium oxide content (A) Determination of silicon content in sodium hydroxide for chemical fibers Reduced silicon molybdate spectrophotometry Appearance: The main body of industrial solid sodium hydroxide is white, shiny, and microband color is allowed. 3.1
3.2 Industrial solid sodium hydroxide (including caustic soda) should comply with the requirements of Table 1: Table 1
item
sodium hydroxide
sodium carbonate||tt ||Sodium chloride
Fe2O3
Mesh
Total calcium and magnesium content (calculated as Ca
)
Silica||tt ||Mercury
Premium product
99.5
0.40
0.06
0.003
0.01
0. 02|| tt||0.0005
Water forging
Other products
99.5
0. 45
0.08
0.004
0.02 | tt||0.005
0.03
0.04
0.0015
refers
standard
harsh
chemical method||tt ||Excellent products
97.0
1.5
1.1
0.008
0.50
Excellent products
97.0||tt ||1.7
1.2
0.01
0.55
Qualified product
96.0
2.5
1.4||tt| |0.01
0.60
Superior product
96.0
1.3
2.7
0.008
Membrane method||tt| |Separation
Other products
96.0
1. 4
2.8
0.01
%
Qualified product|| tt||95.0
1.6
3.2
0.02
1993-10-01 Implementation
GB209-93
3.3 Industrial Liquids Sodium hydroxide should meet the requirements of Table 2: Table 2
refers to the item
item
sodium hydroxide
sodium carbonate
sodium fluoride||tt| |Tools
Fe2O3≤
Total content of calcium and magnesium
(calculated as Ca)≤
Silica
Mercury||tt ||Mercury method
Superior product
First-class product
45.0
0.25
0.03
0.002
0.005|| tt||0.01
0.001
45.0
0.30
0.04
0.003
0.006
0.02||tt| |0.002
Qualified product
42.0
0.35
0.05
0.004
0.007
0.02
0.003
chemical method
harsh
superior product
45.0
1.0
0.70
0.02
0.50
Note: ①Silica and mercury content are type inspection items. ②The data processing in this standard adopts the rounding value comparison method. 4 Testing methods
4.1 Determination of sodium hydroxide content in industrial sodium hydroxide and other products
45.0
1.1
0.80
0. 02| |tt||0.55
Qualified product
42.0
1.5
1.00
0.03
0.60
standard|| tt||Premium products
42.0
0.3
1.6
0.004
According to GB4348.1 and GB11213.1. Among them, GB11213.1 is the arbitration law. 4.2 The determination of sodium carbonate in industrial sodium hydroxide is carried out in accordance with GB7698 and GB4348.1. Among them, GB7698 is the Arbitration Law. 4.3 The determination of sodium chloride in industrial sodium hydroxide is carried out in accordance with GB4348.2.
4.4 The determination of iron content in industrial sodium hydroxide shall be carried out in accordance with GB4348.3.
4.5 The determination of silicon content in industrial sodium hydroxide is carried out in accordance with GB11213.4.
Diaphragm method
Type
Other products
42.0
0.4
1.8
0.007
Qualified Product
42.0
0.6
2.0
0.01
Other products
30.0
0.4
4.7
0.005
%
type
qualified product
30.0
0.6
5.0
0.01| |tt||4.6 Determination of the total calcium and magnesium content in industrial sodium hydroxide by complex titration method. This method specifies the determination method of the total calcium and magnesium content in industrial sodium hydroxide produced by the mercury method. It is suitable for use in industrial sodium hydroxide produced by the mercury method. Sodium hydroxide for industrial use at all levels.
4.6.1 Principle
When the medium pH=10, the calcium and magnesium ions in the sample and the chrome black T indicator form a red complex. When the sodium (disodium EDTA) titration of calcium and magnesium approaches the end point, the indicator forms a blue complex with disodium EDTA, which is the end point. 4.6.2 Reagents and materials
This method uses analytical grade reagents and distilled water or water of corresponding purity. 4.6.2.1 Hydrochloric acid (GB622).
4.6.2.2 Ammonium chloride (GB658).
4.6.2.3 Ammonia (GB631). bzxz.net
4.6.2.4 Ethanol (GB679).
GB209—93
4.6.2.5 Ammonia-ammonium fluoride buffer solution: pH=10, prepared according to GB603. 4.6.2.6 Magnesium standard solution: 0.2432g/L. Weigh 0.2432g of metallic magnesium (99.9%) that has been washed and dried with ethanol (4.6.2.4) and weigh accurately to 0.0002g. Place it in a beaker and add a few drops of hydrochloric acid (4.6.2.1) to dissolve it until no bubbles occur. , heat to complete the reaction, cool and transfer to a 1000mL volumetric flask, dilute to volume, shake well.
4.6.2.7 Disodium ethylenediaminetetraacetate (GB1401) standard titration solution c (disodium EDTA) = 0.005mol/L. Prepared and calibrated according to GB601.
4.6.2.8 Chrome black T indicator (HGB3085): 5g/L ethanol solution. Prepared according to GB603. 4.6.3 Instruments and equipment
General laboratory instruments and
4.6.3.15mL microburette.
4.6.4 Samples
4.6.4.1 Laboratory samples
Sampling shall be carried out in accordance with the provisions of Articles 5.3, 5.4 and 5.5 of this standard. 4.6.4.2 The test sample is the same as the laboratory sample. 4.6.5 Analysis steps
4.6.5.1 Sample
Weigh 10g mercury solid sodium hydroxide or 20g liquid sodium hydroxide, weigh accurately to 0.01g, place it in a 250mL Erlenmeyer flask, and add 1000mL Dissolved in water.
4.6.5.2 Blank test
Without adding any test material, add 10 mL ammonia-ammonium chloride buffer solution (4.6.2.5) to 100 mL water, (**** the same as 4.6.5.3 below), Parallel assays were performed using exactly the same steps as the assay. 4.6.5.3 Determination
Cool the sample (4.6.5.1) and neutralize it with hydrochloric acid (4.6.2.1) to pH=5~6 (check with pH test paper), and then add 3 mL to the excess. Cool to room temperature and adjust to pH=9~10 with ammonia water (4.6.2.3), add 10mL ammonia-ammonium chloride buffer solution (4.6.2.5), 5mL magnesium standard solution (4.6.2.6), 5~6 drops of chrome black T Indicator (4.6.2.8), titrate with EDTA disodium standard titration solution (4.6.2.7) until blue is the end point.
4.6.6 Expression of analysis results
The percentage content (α) of the sum of calcium and magnesium (calculated as calcium) is calculated according to formula (1): 2 × 100 = , - Vo) :c× 4
(V-Vo): c×0.0400
m
m
where: V.
V
When titrating the blank solution, the volume of the EDTA disodium standard titration solution, mL; - When titrating the sample solution, the volume of the EDTA disodium standard titration solution, mL; - EDTA disodium standard Concentration of the titration solution, mol/L; mass of a sample, g
m
0.0400
(1)
and ·1.00mLEDTA disodium standard titration solution (c(disodium EDTA) = 1.000mol/L) equivalent to the mass of calcium expressed in grams.
4.6.7 Allowable difference
GB209-93
The difference between two parallel measurement results shall not exceed 0.0007%, and the arithmetic mean shall be taken as the measurement result. 4.7 Determination of mercury content in industrial sodium hydroxide. Disulfide photometric method. This method specifies the determination method of mercury content in industrial sodium hydroxide produced by mercury method. It is applicable to the mercury content in industrial sodium hydroxide produced by mercury method. Determination of greater than 0.000005%. 4.7.1 Principle
In the medium in the presence of sulfuric acid, use potassium permanganate to oxidize the mercury in the sample into divalent mercury ions, use hydroxylamine hydrochloride to reduce the excess oxidant, and add hydroxylamine hydrochloride and ethylenediamine tetrahydrofuran. Disodium acetate eliminates the interference of copper, iron and silver, and extracts with disulfide adenotrichloromethane solution in the pH range of 0 to 2. The absorbance was measured at a wavelength of 490 nm in the presence of excess disulfide. 4.7.2 Reagents and materials
This method uses analytical grade reagents and distilled water or water of corresponding purity. 4.7.2.1 Chloroform (GB682).
4.7.2.2 Hydrochloric acid (GB622).
4.7.2.3 Sulfuric acid (GB625): 490g/L solution. Take 280mL of sulfuric acid and slowly pour it into water while stirring, dilute to 1000mL, and shake well.
4.7.2.4 Sulfuric acid (GB625): 100g/L solution. Take 60mL of sulfuric acid and slowly pour it into 500mL of water while stirring, dilute to 1000mL, and shake well.
4.7.2.5 Acetic acid (GB676): 360g/L liquid. Take 360mL acetic acid, dilute it with water to 1000mL, and shake well. 4.7.2.6 Disodium ethylenediaminetetraacetate (disodium EDTA) (GB1401): 7.45g/L solution. Weigh 7.45g disodium EDTA into a beaker, add 200mL of water to dissolve, transfer the entire amount to a 1000mL volumetric flask, dilute with water to the mark, and shake well. 4.7.2.7 Potassium permanganate (GB643): 40g/L solution. Weigh 40g of potassium permanganate, dissolve it in water, and dilute to 1000mL. 4.7.2.8 Hydroxylamine hydrochloride (HG3976): 100g/L solution. Weigh 10g of hydroxylamine hydrochloride, dissolve it in water, and dilute to 1000mL. 4.7.2.9 Disulfide: 150mg/L chloroform solution. Weigh 75 mg of disulfide, place it in a 500 mL volumetric flask, dilute to the mark with chloroform (4.7.2.1), and shake well. Stored in brown bottles, the solution is valid within two weeks at 25°C. 4.7.2.10 Disulfide gland: 1.5mg/L solution. Take 5 mL of disulfonate solution (4.7.2.9), place it in a 500 mL volumetric flask, dilute to the mark with trifluoromethane (4.7.2.1), and shake well. Prepare this solution before use and place it in a dark and cool place. 4.7.2.11° Mercury standard solution: 1mg/mL. Weigh 1.354g of mercuric chloride (HG31063) and dissolve it in 25mL of concentrated hydrochloric acid. Transfer the entire volume into a 1000mL volumetric flask, dilute to the mark with water, and shake well. This solution is stored in a dark place and is effective within two months. 4.7.2.12 Mercury standard solution: 20 μg/mL. Take 10.0 mL of mercury standard solution (4.7.2.11), place it in a 500 mL volumetric flask, add 10 mL of concentrated hydrochloric acid (4.7.2.2), dilute to volume with water, and shake well. Prepare this solution before use. 4.7.2.13 Mercury standard solution: 1μg/mL. Take 10.0 mL of mercury standard solution (4.7.2.12), place it in a 200 mL volumetric flask, add 5 mL of concentrated hydrochloric acid (4.7.2.2), dilute to the mark with water, and shake well. Prepare this solution before use. 4.7.3 Instruments and Equipment
General laboratory instruments and
4.7.3.1 Spectrophotometer.
4.7.3.2 All instruments that have not been used for mercury content determination, including blood vessels containing reagents and samples, should be washed with 1.42g/mL nitric acid solution first, and then washed with sulfuric acid (4.7.2.4) and high manganese Wash with potassium acid (4.7.2.7) mixed solution (prepared at a volume ratio of 4:1). 4.7.4 Samples
4.7.4.1 Laboratory samples
Sampling shall be carried out in accordance with the provisions of Articles 5.3, 5.4 and 5.5 of this standard. 4.7.4.2 Sample
After weighing the laboratory sample, take 20g solid sodium hydroxide or 40g liquid sodium hydroxide (shake before weighing), weigh accurately to 0.1g, place it in a beaker, add water to dissolve, Add 5 mL of potassium permanganate solution (4.7.2.7), add 85 mL of sulfuric acid solution (4.7.2.3) while stirring, cover with surface blood, boil for 10 minutes, cool to room temperature, and then add hydroxylamine hydrochloride solution (4.7.2.8) dropwise. When the potassium permanganate discolors, add an excess of about 0.25mL. Transfer the entire GB209-93
into a 500mL volumetric flask, dilute to the mark, and shake well. 4.7.5 Determination of mercury content in the sample
4.7.5.1 Sample
Take 25.0mL of the sample solution (4.7.4.2), place it in the lower neck and dry it with filter paper in advance and stuff it with a Put a small ball of filter paper in the separatory funnel and wait for measurement.
4.7.5.2 Blank test
No sample is added, and the same analysis steps, reagents and dosages are used for parallel measurement. 4.7.5.3 Determination of
a. Extraction of mercury
Add 30 mL of sulfuric acid solution (4.7.2.3) to the sample (4.7.5.1), dilute to 300 mL with water, and add 1 mL of hydroxylamine hydrochloride solution (4.7 .2.8), 10 mL acetic acid solution (4.7.2.5) and 10 mL LEDTA disodium solution (4.7.2.6), plus 25.0 mL disulfide gland solution (4.7:2.10), shake vigorously for 1 min, and rest for 10 min. b. Determination of absorbance
Use 5cm colorimetric blood, adjust the absorbance of the spectrophotometer to zero with chloroform (4.7.2.1) at a wavelength of 490nm, and then measure the mercury extract (4.7.5.3.a) The absorbance is used to calculate the mercury content (r) in the sample. 4.7.6 Determination of mercury content adsorbed on the bottle wall. Empty all samples in the laboratory sample bottle, and take 10 mL of potassium permanganate solution (4.7.2.7) and 40 mL of sulfuric acid solution (4.7.2.4), place it in an empty sample bottle, shake vigorously for 1 hour, and then measure the absorbance according to step (4.7.5), which is used to calculate the mercury content (rz) adsorbed on the bottle wall.
4.7.7 Drawing of working curve
4.7.7.1 Preparation of standard reference solution
Take six 500mL separatory funnels, dry the lower neck with filter paper, and insert A small ball of filter paper, add 30mL sulfuric acid solution (4.7.2.3) to each separatory funnel, take 0.0, 2.0, 3.0, 4.0, 6.0, 8.0mL mercury standard solution (4.7.2.13) in sequence, and place them in six In a separatory funnel, follow the steps of "dilute to 300 mL with water,..." in (4.7.5.3a). 4.7.7.2 Determination of the absorbance of the standard reference solution: Measure the absorbance of the standard reference solution (4.7.7.1) according to the steps (4.7.5.3b). Subtract the absorbance of the blank test from the absorbance of the standard reference solution. Draw the working curve with the mercury mass (ug) as the abscissa and its corresponding absorbance as the ordinate. 4.7.8 Expression of analysis results
From the standard curve (4.7.7.2), find the mercury mass (μg) corresponding to the measured absorbance. The percentage content of mercury (α) is calculated according to formulas (2) to (4):
t,
where: mo
mg-|| tt||m
m total
(m,-m)×10-6
mv
500
(mz-mo)×10 -6
mv
500
+
The mass of mercury corresponding to the absorbance of the blank test solution, ug; the mass of mercury corresponding to the absorbance of the sample solution, ug; bottle The mass of mercury corresponding to the absorbance of the wall recovery liquid, ug; the mass of the sample, g;
the total mass of the laboratory sample, g;
the volume of the sample, mL.
4.7.9 Allowable difference
× 100
× 100
·(2)
·(3)
(4)
GB209-93
The difference between the two parallel measurement results shall not exceed 0.00005%, and the arithmetic mean shall be taken as the measurement result. 5 Inspection Rules
5.1 Industrial sodium hydroxide should be inspected by the quality inspection department of the production unit. Each batch of industrial sodium hydroxide leaving the factory should meet the requirements of this standard and be accompanied by a certain format of quality certificate. Book. 5.2 The user has the right to inspect and accept the received industrial sodium hydroxide in accordance with the technical indicators, inspection rules and test methods specified in this standard.
5.3 Laboratory samples of industrial solid sodium hydroxide should be taken from 5% of the total number of barrels. For small batches, it should not be less than 3 barrels. Cut the barrel skin along the vertical interface of the barrel, split the alkali, and remove the alkali from the barrel. Quickly take out representative samples from the upper, middle and lower places and mix them evenly. Put it in a clean, dry, wide-mouth bottle with a rubber stopper and seal it (if silica is measured, it should be put in a clean, dry, polyethylene bottle with a stopper and seal it). The sampling volume shall not be less than 500g. The manufacturer can take molten alkali in the packaging barrel as a laboratory sample for inspection. Sampling is carried out at 5% of the number of barrels in each batch (including the first and last two barrels), and the obtained laboratory samples are placed in clean, dry and stoppered wide-mouth bottles, sealed (if the silica content is measured, they should be packed Place in a clean, dry, stoppered, foil-lined jar and seal). The sampling volume shall not be less than 500g. If any objection arises due to different sampling methods affecting product quality, the cut-barrel sampling method shall prevail. 5.4 Take equal amounts of industrial liquid sodium hydroxide samples from the upper, middle and lower places of the tanker or storage tank (the upper part is 1/10 liquid layer away from the liquid surface, the lower part is 1/10 liquid layer away from the bottom), and mix well (if When measuring silica, use plastic bottles for sampling). The sampling volume shall not be less than 500mL. 5.5 Laboratory sample bottles should be marked with: manufacturer name, product name, brand type, batch number or tanker number, sampling date and name of the sampler.
5.6 If an indicator of the inspection result does not meet the technical requirements of this standard, laboratory samples should be taken from tank trucks, storage tanks and barrels with twice the amount for re-test. As a result of re-inspection, even if only one indicator does not meet the technical requirements of this standard, the entire batch of products will be deemed unqualified. 5.7 Sample retention
Domestic samples of industrial solid sodium hydroxide should be retained for three months, export samples should be retained for six months, and industrial liquid sodium hydroxide samples should be retained in plastic bottles for one month for future reference.
5.8 When the supply and demand parties have objections to product quality, the quality arbitration unit shall arbitrate. 6 Marking, packaging, transportation and storage
6.1 Marking
Industrial sodium hydroxide packaging containers must have obvious and firm marks, which include: manufacturer name, product name, trademark, standards No., grade, production date, batch number and net weight, and have the mark of "corrosive substances". 6.2 Packaging
Industrial solid sodium hydroxide should be packed in iron drums. The thickness of the drum wall should be more than 0.5mm and the pressure resistance should be more than 0.05MPa. The lid of the drum must be tightly sealed. The net weight of each barrel is 200kg, and the caustic soda is 25kg. When industrial liquid sodium hydroxide is shipped in a tanker or storage tank, it must be cleaned after two uses. 6.3 Transportation and Storage
Industrial sodium hydroxide should be stored in a dry warehouse to avoid damage, contamination, moisture and contact with acid. Protect against impact during transportation. Product quality must not be affected during transportation and storage. 7 Safety
Sodium hydroxide is highly corrosive, and labor protection equipment such as protective glasses and rubber gloves must be worn during operation. Additional notes:
GB209-93
This standard is proposed by the National Chemical Standardization Technical Committee. This standard is under the technical jurisdiction of Jinxi Chemical Industry Research Institute of the Ministry of Chemical Industry. The main drafters of this standard are Tang Shijie, Guo Baoyu, Wu Liping, Guo Biao and Tian Youli. This standard refers to the former Soviet national standard rOCT2263-79 "Industrial Sodium Hydroxide Process Conditions"3 For industrial solid sodium hydroxide, laboratory samples should be taken from 5% of the total number of barrels. For small batches, it should not be less than 3 barrels. Cut the barrel skin along the vertical interface of the barrel, split the alkali, and remove the alkali from the top, middle and bottom. Quickly take out representative samples from three places and mix them evenly. Put it in a clean, dry, wide-mouth bottle with a rubber stopper and seal it (if silica is measured, it should be put in a clean, dry, polyethylene bottle with a stopper and seal it). The sampling volume shall not be less than 500g. The manufacturer can take molten alkali in the packaging barrel as a laboratory sample for inspection. Sampling is carried out at 5% of the number of barrels in each batch (including the first and last two barrels), and the obtained laboratory samples are placed in clean, dry and stoppered wide-mouth bottles, sealed (if the silica content is measured, they should be packed Place in a clean, dry, stoppered, foil-lined jar and seal). The sampling volume shall not be less than 500g. If any objection arises due to different sampling methods affecting product quality, the cut-barrel sampling method shall prevail. 5.4 Take equal amounts of industrial liquid sodium hydroxide samples from the upper, middle and lower places of the tanker or storage tank (the upper part is 1/10 liquid layer away from the liquid surface, the lower part is 1/10 liquid layer away from the bottom layer), and mix well (if When measuring silica, use plastic bottles for sampling). The sampling volume shall not be less than 500mL. 5.5 Laboratory sample bottles should be marked with: manufacturer name, product name, brand type, batch number or tanker number, sampling date and name of the sampler.
5.6 If an indicator of the inspection result does not meet the technical requirements of this standard, laboratory samples should be taken from tank trucks, storage tanks and barrels with twice the amount for re-test. As a result of re-inspection, even if only one indicator does not meet the technical requirements of this standard, the entire batch of products will be deemed unqualified. 5.7 Sample retention
Domestic samples of industrial solid sodium hydroxide should be retained for three months, export samples should be retained for six months, and industrial liquid sodium hydroxide samples should be retained in plastic bottles for one month for future reference.
5.8 When the supply and demand parties have objections to product quality, the quality arbitration unit shall arbitrate. 6 Marking, packaging, transportation and storage
6.1 Marking
Industrial sodium hydroxide packaging containers must have obvious and firm marks, which include: manufacturer name, product name, trademark, standards No., grade, production date, batch number and net weight, and have the mark of "corrosive substances". 6.2 Packaging
Industrial solid sodium hydroxide should be packed in iron drums. The thickness of the drum wall should be more than 0.5mm and the pressure resistance should be more than 0.05MPa. The lid of the drum must be tightly sealed. The net weight of each barrel is 200kg, and the caustic soda is 25kg. When industrial liquid sodium hydroxide is shipped in a tanker or storage tank, it must be cleaned after two uses. 6.3 Transportation and Storage
Industrial sodium hydroxide should be stored in a dry warehouse to avoid damage, contamination, moisture and contact with acid. Protect from impact during transportation. Product quality must not be affected during transportation and storage. 7 Safety
Sodium hydroxide is highly corrosive, and labor protection equipment such as protective glasses and rubber gloves must be worn during operation. Additional notes:
GB209-93
This standard is proposed by the National Chemical Standardization Technical Committee. This standard is under the technical jurisdiction of Jinxi Chemical Industry Research Institute of the Ministry of Chemical Industry. The main drafters of this standard are Tang Shijie, Guo Baoyu, Wu Liping, Guo Biao and Tian Youli. This standard refers to the former Soviet national standard rOCT2263-79 "Industrial Sodium Hydroxide Process Conditions"3 For industrial solid sodium hydroxide, laboratory samples should be taken from 5% of the total number of barrels. For small batches, it should not be less than 3 barrels. Cut the barrel skin along the vertical interface of the barrel, split the alkali, and remove the alkali from the top, middle and bottom. Quickly take out representative samples from three places and mix them evenly. Put it in a clean, dry, wide-mouth bottle with a rubber stopper and seal it (if silica is measured, it should be put in a clean, dry, polyethylene bottle with a stopper and seal it). The sample size shall not be less than 500g. The manufacturer can take molten alkali in the packaging barrel as a laboratory sample for inspection. Sampling is carried out at 5% of the number of barrels in each batch (including the first and last two barrels), and the obtained laboratory samples are placed in clean, dry and stoppered wide-mouth bottles, sealed (if the silica content is measured, they should be packed Place in a clean, dry, stoppered, foil-lined jar and seal). The sample size shall not be less than 500g. If any objection arises due to different sampling methods affecting product quality, the cut-barrel sampling method shall prevail. 5.4 Take equal amounts of industrial liquid sodium hydroxide samples from the upper, middle and lower places of the tanker or storage tank (the upper part is 1/10 liquid layer away from the liquid surface, the lower part is 1/10 liquid layer away from the bottom layer), and mix well (if When measuring silica, use plastic bottles for sampling). The sampling volume shall not be less than 500mL. 5.5 Laboratory sample bottles should be marked with: manufacturer name, product name, brand type, batch number or tanker number, sampling date and name of the sampler.
5.6 If an indicator of the inspection result does not meet the technical requirements of this standard, laboratory samples should be taken from tank trucks, storage tanks and barrels with twice the amount for re-test. As a result of re-inspection, even if only one indicator does not meet the technical requirements of this standard, the entire batch of products will be deemed unqualified. 5.7 Sample retention
Domestic samples of industrial solid sodium hydroxide should be retained for three months, export samples should be retained for six months, and industrial liquid sodium hydroxide samples should be retained in plastic bottles for one month for future reference.
5.8 When the supply and demand parties have objections to product quality, the quality arbitration unit shall arbitrate. 6 Marking, packaging, transportation and storage
6.1 Marking
Industrial sodium hydroxide packaging containers must have obvious and firm marks, which include: manufacturer name, product name, trademark, standards No., grade, production date, batch number and net weight, and have the mark of "corrosive substances". 6.2 Packaging
Industrial solid sodium hydroxide should be packed in iron drums. The thickness of the drum wall should be more than 0.5mm and the pressure resistance should be more than 0.05MPa. The lid of the drum must be tightly sealed. The net weight of each barrel is 200kg, and the caustic soda is 25kg. When industrial liquid sodium hydroxide is shipped in a tanker or storage tank, it must be cleaned after two uses. 6.3 Transportation and Storage
Industrial sodium hydroxide should be stored in a dry warehouse to avoid damage, contamination, moisture and contact with acid. Protect against impact during transportation. Product quality must not be affected during transportation and storage. 7 Safety
Sodium hydroxide is highly corrosive, and labor protection equipment such as protective glasses and rubber gloves must be worn during operation. Additional notes:
GB209-93
This standard is proposed by the National Chemical Standardization Technical Committee. This standard is under the technical jurisdiction of Jinxi Chemical Industry Research Institute of the Ministry of Chemical Industry. The main drafters of this standard are Tang Shijie, Guo Baoyu, Wu Liping, Guo Biao and Tian Youli. This standard refers to the former Soviet Union national standard rOCT2263-79 "Industrial Sodium Hydroxide Process Conditions"
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