Some standard content:
GB 7744—1998 | Category A indicators, the total acidity and fluorosilicic acid content (0.2% ~ 10%) in the test method, as well as the non-volatile acid content, are equivalent to ISO3139: 1976 "Industrial Aqueous Hydrofluoric Acid - Sampling and Test Methods"; Fluorine Silicic acid content (0.0005%~~0.2%) is measured equivalently using ISO3701: 1976 "Anhydrous hydrogen fluoride for industrial use - Determination of hexafluorosilicic acid content - Reduced silicomolybdate photometric method".
The main technical differences with the Russian national standards are as follows: The Russian national standards have two categories: Class A and Class B, and Class B is divided into two levels. This standard sets up superior products and first-class products based on actual production and user needs. There are three levels of first-class products and qualified products, and there are two types of first-class products and qualified products. The main technical differences between this standard and the original national standard are as follows: 1. The original national standard includes superior products, first-class products and second-class products, while this national standard includes superior products, first-class products and qualified products. 2. The iron content index has been deleted for high-quality products. The reason is: it is equivalent to adopting the Russian national standard Class A technical index. Domestic production practices and users have no objection to the deletion of this index. First-class products and qualified products have canceled the F-60 specification. Mainly The reason is safety considerations. 3. According to the requirements of the allowable relative error of general industrial analysis, the allowable differences of the fluorosilicic acid content and the non-volatile acid content have been appropriately adjusted.
This standard will replace GB7744-1987 and GB7745.17745.4-1987 from the date of implementation. This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the technical unit responsible for standardization of inorganic salt products of the Ministry of Chemical Industry. This standard was drafted by: Tianjin Chemical Industry Research Institute of the Ministry of Chemical Industry, Zhejiang Yingguang Chemical Co., Ltd., Baotou No. 1 Chemical Factory, Jiangsu Sheyang County Fluorine Chemical Factory, Zhejiang Yingpeng Chemical Co., Ltd. The main drafters of this standard: Su Peiji, Wu Yimin, Hao Runqi, Yu Guanghui, Zhu Rongzhong. This standard was first published in May 1987.
This standard is entrusted to the inorganic salt product standardization technical unit of the Ministry of Chemical Industry to be responsible for interpretation. 473
1 Scope
National Standard of the People's Republic of China
Hydrofluoric acid
Industrial
Hydrofluoric acid for industrial useGB 7744—1998
Replaces GB7744
-1987
GB 7745.17745. 4--1987
This standard specifies the requirements, test methods, inspection rules and marking, packaging, transportation, Storage and safety. This standard applies to hydrofluoric acid, which is mainly used in chemical industry, metallurgy, glass, mining, concurrent oil mining, atomic energy and other industries. Molecular formula: HF | . At the time of publication, the editions indicated were valid. All standards are subject to revision and parties using this standard should explore the possibility of using the latest version of the standard listed below. GB190-1990 Dangerous goods packaging markings
GB191-1990 Packaging, storage and transportation pictorial markings
GB/T601-1988 Preparation of standard solutions for chemical reagent titration analysis (volume analysis) GB/T602--1988 Preparation of standard solutions for determination of impurities in chemical reagents (neqISO6353-1:1982) Preparation of preparations and products used in chemical reagent test methods (neqISO6353-1:1982) GB/T 603—1988
GB/T 1250- -1989
GB/T 6678--1986
GB/T 6682—1992
3 requirements
Expression method and judgment method of limit values ??General principles for sampling of chemical products| |tt||Analytical laboratory water specifications and test methods (neqISO3696:1987) 3.1 Appearance: This product is a colorless and transparent solution. 3.2 Industrial hydrofluoric acid should comply with the requirements in Table 1. Table 1 requirements
item
hydrogen fluoride content
fluorosilicic acid content
item
non-volatile acid (calculated as H, SO.) content ≤| |tt||4 test methods
Superior product
HF-40
40.0
0. 02
0.02
40.0|| tt||0. 2
0.05
refers to
other products
label
HF-55
55.0
0.5
0.08
Qualified product
HF-40
40.0
2.5
1.0
%||tt| |HF-55
55.0
5.0
2.0
The reagents and water used in this standard refer to analytical grade reagents and GB/ Class 3 water specified in T6682. Approved by the State Administration of Quality and Technical Supervision on 1998-10-19 474
1999-04-01 Implementation
GB 77441998
Standard titration solutions, impurity standard solutions, preparations and products required in the test , unless other requirements are noted, they shall be prepared in accordance with the provisions of GB/T601, GB/T602, and GB/T603. Warning: The hydrofluoric acid used in the test is corrosive, so care should be taken during operation, and heating should be performed in a fume hood. 4.1 Determination of total acidity and fluosilicic acid (0.2% ~ 10%) content 4.1.1 Method summary
In the presence of potassium nitrate, use phenol as an indicator, titrate with sodium hydroxide standard titration solution and cool with ice of test solution. Then reheat and continue titration. The first titration corresponds to an acid other than fluosilicic acid and two moles of acid released when precipitating fluosilicic acid. The second titration corresponds to the remaining four moles of acid released upon heating and hydrolysis of the precipitated potassium fluorosilicate. 4.1.2 Reagents and materials
4.1.2.1 Potassium nitrate solution: saturated at room temperature. 4.1.2.2 Sodium hydroxide standard titration solution: c (NaOH) is about 1 mol/L. 4.1.2.3 Sodium hydroxide standard titration solution: c (NaOH) is about 0.1 mol/L. 4.1.2.4 Phenol indicator solution: 10g/L, dissolve 1g phenol in 100mL ethanol, and add sodium hydroxide standard titration solution (4.1.2.3) dropwise until light pink appears.
4.1.2.5 Crushed ice (frozen in distilled water or water of corresponding purity). 4.1.3 Instruments and equipment wwW.bzxz.Net
Polyethylene sample bottle with cap (capillary on the cap): volume 150mL, with a scale at 100ml. 4.1.4 Analysis steps
4.1.4.1 Preparation of diluted samples
Use a sample bottle with a known weight to weigh the crushed ice and weigh it accurately to 0.01g. The corresponding relationship between the weighed crushed ice mass and sample concentration is listed in Table 2.
Table 2 Sample concentration and corresponding sample concentration of weighed crushed ice mass, %
40~50
50~60
>60
Mass of crushed ice, g
0
15
35
Carefully add the sample to the sample bottle, add it to the mark, and weigh it again to make sure it is accurate to 0.01g, shake the hook to get the diluted sample. 4.1.4.2 Determination
Weigh about 1.5g of the diluted sample in a polyethylene sample bottle with a lid, weigh it accurately to 0.0002g, and place it in a 250mL polyethylene beaker. The beaker is already filled with 20 mL of potassium nitrate solution. Add approximately 20 mL of sodium hydroxide standard titration solution (4.1.2.2) and crushed ice from the burette. Rinse the weighing bottle with cooled water and collect the washing liquid in the same beaker. Add 3 drops of phenolic indicator solution and keep the solution ice cold. Continue to titrate with the sodium hydroxide standard titration solution in the above burette until it is close to the end point, and then titrate with the sodium hydroxide standard titration solution (4.1.2.3) until the light pink color that appears does not disappear for 15 seconds is the end point. Transfer all this solution to a 400mL glass beaker, heat it until it just boils, and immediately titrate with sodium hydroxide standard titration solution (4.1.2.3) until the light pink color appears and does not disappear for 15 seconds as the end point. 4.1.5 Expression of analysis results
4.1.5.1Total acidity
The total acidity (in HF) content (X) expressed as mass percentage is calculated according to formula (1): X = (GV++cV2+cV) × 0. 020 01 × 100 ×mi
m
2. 001(cVi+c2V, + caV,)ml
m(m - mz)
Sodium hydroxide standard titration solution (4.1.2.2 ) concentration, mo1/L; where: i——
mi-mz
(1)
475
GB 7744--1998
Concentration of sodium hydroxide standard titration solution (4.1.2.3), mol/L; C2
V.—the volume of sodium hydroxide standard titration solution (4.1.2.2) consumed in the first titration, mL, Vz- - The volume of the sodium hydroxide standard titration solution (4.1.2.3) consumed for the first titration, mL, V: - The volume of the sodium hydroxide standard titration solution (4.1.2.3) consumed for the second titration, mL, m-
The mass of the diluted sample weighed when measuring, g; mi-the total mass of the diluted sample prepared, g; m2
The mass of crushed ice weighed when preparing the diluted sample, g ;0.02001--the mass of oxygen fluoride in grams equivalent to 1.00mL sodium hydroxide standard titration solution [c(NaOH)=1.000mol/L}.
4.1.5.2 Fluosilicic acid
The fluosilicic acid content (X2) expressed as mass percentage is calculated according to formula (2): _cV. × 0. 036 02 × 100
|tt||V
Same as 4.1.5.1;
Same as 4.1.5.1;
m
Same as 4.1.5.1;
m||tt ||Same as 4.1.5.1;
m
m - m2
(2)
between 4.1.5.13
m2
one The mass of fluosilicic acid 0. 036 02
expressed in grams that is equivalent to 1.00mL sodium hydroxide standard titration solution [c(NaOH)=1.000mol/L.
4.1.5.3 Hydrogen fluoride
The hydrogen fluoride content (X) expressed as mass percentage is calculated according to formula (3): X3 - X — 0. 833 2 (X2 or X) - 0. 408 4Xs - .In the formula: X1
X, or Volatile acid content, %;
0.8332--The coefficient of converting monofluorosilicic acid into hydrogen fluoride; 0.408 4
The coefficient of converting sulfuric acid into hydrogen fluoride.
4.1.6 Allowable difference
4.1.6.1 Total acidity
Take the arithmetic mean of the parallel measurement results as the measurement result. The absolute difference of the parallel measurement results shall not be greater than 0.4%. (3)
4.1.6.2 Fluorosilicic acid
Take the arithmetic mean of the parallel measurement results as the measurement result. The absolute difference of the parallel measurement results is not greater than: content 0.2%~~0.5% is 0.05 %; content 0.5% to 5% is 0.1%. 4.2 Determination of fluosilicic acid content (0.0005%~0.2%) 4.2.1 Method summary
Fluorosilicic acid and sodium chloride generate sodium fluosilicate. The hydrogen fluoride is removed by evaporation. In a weakly acidic medium and in the presence of boric acid that can suppress fluorine interference, silicates react with ammonium molybdate to form silicomolybdate heteropoly acid (yellow). Sulfuric acid solution and oxalic acid solution are added to eliminate the interference of phosphate, and then the silicomolybdenum heteropoly acid is reduced. The absorbance of the blue complex was measured at a wavelength of 795 nm. 4.2.2 Reagents and materials
4.2.2.1 Sodium chloride solution: 10g/L;
476
4.2.2.2 Sulfuric acid solution: 1+3;
4.2 .2.3 Hydrochloric acid solution: 1+5;
4.2.2.4 Boric acid solution: 40g/L;
4.2.2.5 Oxalic acid solution: 100g/L;
GB 77441998||tt| |4.2.2.6 Ammonium molybdate solution: 100g/L (re-preparation is required when the solution precipitates); 4.2.2.7 reducing solution
4.2.2.7.1 Dissolve 7g anhydrous sodium sulfite in 50ml water, add Dissolve 1.5g 1-amino-2-naphthol-4-sulfonic acid; 4.2.2.7.2 Dissolve 90g sodium metabisulfite in 900mL water; 4.2.2.7.3 Mix 4.2.2.7.1 and 4.2.2.7.2 The solution is diluted to 1000mL and filtered if necessary. Store the solution in a cool and dark place to avoid direct sunlight. The service life should not exceed 20 days; 4.2.2.8 Silica standard solution, 1mL is equivalent to 1.000mgHzSiF: weigh and burn at 1000℃ to constant temperature. Add 0.417g of heavy silica to platinum, add 5g of anhydrous sodium carbonate, mix thoroughly, place in a high temperature furnace at 1000°C to slowly melt, let cool, add hot water to dissolve. After cooling, transfer everything to a 1000mL volumetric flask medium, dilute to volume and shake well. Transfer immediately to polyethylene bottles. This solution should be remade at least monthly.
4.2.2.9 Silica standard solution, 1mI is equivalent to 0.050mgHzSiFe: Pipette 50mL silica standard solution (4.2.2.8), place it in a 1000mL volumetric flask, dilute to the mark, and shake well. Prepare this solution just before use. 4.2.3 Instruments and equipment
4.2.3.1 Spectrophotometer;
4.2.3.2 Platinum, with a volume of about 100mL.
4.2.4 Analysis steps
4.2.4.1 Drawing of working curve
In a series of 100mL volumetric flasks, add 0, 2.00, 4.00, 6.00, 8.00mL and 10.00mL respectively. Silica standard solution (4.2.2.9), add water to 10mL, add 10mL sodium chloride solution, add 4mL hydrochloric acid solution and 35mL boric acid solution while stirring, leave for 5 minutes, add 10mL ammonium molybdate solution, shake well, and leave for 15min. Add 5 mL of oxalic acid solution and 20 mL of sulfuric acid solution respectively while stirring, shake well, then add 2 mL of reducing solution, dilute to the mark with water, shake well, and leave for 20 minutes. Adjust the wavelength of the spectrophotometer to 795nm, use a 2cm absorption cell, and use water as a reference to measure the absorbance of each standard solution. Subtract the absorbance of the zero ml silica standard solution from the absorbance of each standard solution. Taking the fluorosilicic acid content as the abscissa and the corresponding absorbance as the ordinate, draw a working curve. 4.2.4.2 Determination
4.2.4.2.1 Preparation of blank test solution
Add 10 mL water and 10 mL sodium chloride solution to platinum III and shake well. 4.2.4.2.2 Determination
Fill the platinum blood with 10 mL of sodium chloride solution 1 and weigh it to the nearest 0.01g. According to the content of fluorosilicic acid, add about 0.25 to 2g of the sample (5.3.2) and weigh it again to the nearest 0.01g in order to calculate the mass of the sample taken. At the same time, handle it in the same way as the blank test solution as follows. Place it on a water bath and evaporate to dryness 2], add 10 mL water, 4 mL hydrochloric acid solution, and 35 mL boric acid solution, leave it for 5 minutes, add 10 mL ammonium molybdate solution, mix, and transfer all the solutions into a 100 mL volumetric flask. Follow the steps for drawing a working curve, starting from "leave it on for 15 minutes."
According to the measured absorbance, find out the fluorosilicic acid content from the standard curve. 4.2.5 Expression of analysis results
Adoption instructions:
11IS()3701:1976 does not have this step.
2}IS()3701:1976 does not have this step.
477
GB 7744—1998
The fluorosilicic acid content (X.) expressed as mass percentage is calculated according to formula (4): × 100 = 0. 1 (m, - m2)
m-m2
, mg; m2——The amount of fluorosilicic acid in the blank test solution found from the working curve, mg; m
Sample mass, g.
4.2.6 Allowable difference
m
(4)
Take the arithmetic mean of the parallel measurement results as the measurement result. The absolute difference of the parallel measurement results is not greater than: the content is not greater than 0.02% It is 0.002%; if the content is not more than 0.2%, it is 0.01%. 4.3 Determination of non-volatile acid content
4.3.1 Method summary
After removing the volatile acid by evaporation, use phenolic acid as an indicator and titrate the non-volatile acid with sodium hydroxide standard titration solution. 4.3.2 Reagents and materials
4.3.2.1 Sodium hydroxide standard titration solution: c (NaQH) about 0.1mol/L more 4.3.2.2 Phenolic acid indicator solution: 10g/L, dissolve 1g phenol in 100mL ethanol , add sodium hydroxide standard titration solution dropwise until light pink appears;
4.3.2.3 Carbon dioxide-free water.
4.3.3 Instruments and equipment
4.3.3.1 Platinum III: the volume is about 100mL,
4.3.3.2 Polyethylene dropper: the volume is 2mL. 4.3.4 Analysis steps
Use a platinum dish to weigh 20~~40g sample (5.3.2), accurate to 0.01g. When measuring the non-volatile acid content in high-quality products, 60g sample should be weighed and weighed Accurate to 0.01g. Place it in platinum blood, evaporate it to nearly dryness on a boiling water bath in a fume hood, wash the inner wall of the platinum blood with a small amount of water, and evaporate it again until it is nearly dry. Repeat this operation until the steam is no longer acidic (check with a wet pH test paper). Then transfer all the residual liquid into a 250mL Erlenmeyer flask, and rinse the platinum blood with a total volume of approximately 100mL carbon dioxide-free water. Add 3 drops of phenolic acid indicator solution and titrate with sodium hydroxide standard titration solution until it turns light pink.
4.3.5 Expression of analysis results
The non-volatile acid (calculated as H, SO4) content (Xs) expressed as mass percentage is calculated according to formula (5): Vc× 0. 049 × 100 = 4. 9Vc
mL; c-actual concentration of sodium hydroxide standard titration solution, mol/L; (5)
0.049 - equivalent to 1.00mL sodium hydroxide standard titration solution LcNaOH) = 1.000mol/L] expressed in grams Mass of non-volatile acid (calculated as H, SQ.),
Sample mass, g.
1
4.3.6 Allowable difference
Take the arithmetic mean of the parallel measurement results as the measurement result. The absolute difference of the parallel measurement results is not greater than: 0.01% for superior products; etc. The product is 0.02%; the qualified product is 0.05%. 5 Inspection rules
5.1 All items specified in this standard are factory inspection items. 5.2 Each batch of industrial hydrofluoric acid products shall not exceed 50t. 5.3 Sampling | |tt | When filling cans, each tank is a batch and one sample is taken.
5.3.2 Sampling method
Insert the plastic sampling tube into the bottom of the packaging container to extract the sample. For packaging of steel containers, samples should be taken from the upper and lower parts of each container. The sample taken should not be less than 500g, mix it evenly, put it into two clean, dry plastic containers, and seal it with wax. A label should be attached to the bottle, indicating: manufacturer name, product name, batch number, model, sampling date and name of the sampler. One bottle is used for inspection and the other bottle is kept for three months for future reference. 5.4 Hydrofluoric acid should be inspected by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer should ensure that each batch of products shipped meets the requirements of this standard.
If any of the indicators in the inspection results does not meet the requirements of this standard, resampling should be carried out from twice the amount of packaging units for re-inspection. If the re-inspection results even if one indicator does not meet the requirements of this standard, The entire batch of products is deemed to be unqualified. 5.5 Determine whether the inspection results meet the standards according to the rounding value comparison method specified in 5.2 of GB/T1250-1989. 6 Marking, packaging, transportation, storage
6.1 Industrial hydrofluoric acid packaging containers should have firm and clear markings, including: manufacturer name, factory address, product name, trademark, grade, model, net content, content The standard number is as well as the mark 14 "drugs" mark, mark 20 "corrosives" mark in GB190-1990, and mark 3 "upward" mark and mark 4 "heat-resistant" mark in GB191-1990. 6.2 Each batch of products leaving the factory should be accompanied by a quality certificate, which includes: manufacturer name, factory address, product name, trademark, grade, net content, batch number, model or production date, proof that the product quality complies with this standard and this standard serial number. 6.3 Industrial hydrofluoric acid is packaged in corrosion-resistant steel containers or plastic containers. For plastic container packaging, the barrel thickness should be more than 3mm, the blow molding thickness should be uniform, and it should have anti-aging and anti-freezing properties as well as pressure resistance, puncture resistance, and anti-friction functions that meet the regulations. Plastic buckets must not be made of any used plastic. The mouth of the barrel should be a small opening, which should be plugged tightly with a bowl-shaped cover. The threaded mouth, cover, gasket and other sealing parts should be in good condition, tightly screwed, and liquid-tight. The net weight of each piece shall not exceed 50kg. When transported by sea, the volume of hydrofluoric acid liquid shall not exceed 250L. Use container transportation. 6.4 Industrial hydrofluoric acid is transported by railway tank cars, boxcars, covered cars or ships. When transported by railway tank cars, the longitudinal middle part of the tank body should be painted with a black 300mm horizontal annular ribbon. When packed in plastic barrels, only the whole vehicle can be transported. It is strictly forbidden to be exposed to moisture, heat and rain during transportation. During shipment, it should be loaded and unloaded lightly, and collisions should be avoided. 6.5 Industrial hydrofluoric acid should be stored in a well-ventilated warehouse. The temperature in the warehouse should be kept below 30°C and the relative humidity below 85%. 7 Safety
7.1 Hydrofluoric acid is a highly corrosive solution. Its vapor is irritating and toxic. It has a strong corrosive effect on the skin and eyes, can cause severe burns, and the treatment effect is slow. The maximum allowed in the air is The concentration is 1mg/m3. 7.2 It must be taken in a well-ventilated place or fume hood. Wear protective equipment of appropriate size. If you come into contact or suspect that you have come into contact with hydrofluoric acid, rinse with plenty of water and treat immediately. 479
6 Allowable difference
Take the arithmetic mean of the parallel measurement results as the measurement result. The absolute difference of the parallel measurement results is not greater than: 0.01% for superior products; 0.02% for equal products; 0.05% for qualified products. 5 Inspection rules
5.1 All items specified in this standard are factory inspection items. 5.2 Each batch of industrial hydrofluoric acid products shall not exceed 50t. 5.3 Sampling | |tt | When filling cans, each tank is a batch and one sample is taken.
5.3.2 Sampling method
Insert the plastic sampling tube into the bottom of the packaging container to extract the sample. For packaging of steel containers, samples should be taken from the upper and lower parts of each container. The sample taken should not be less than 500g, mix it evenly, put it into two clean, dry plastic containers, and seal it with wax. A label should be attached to the bottle to indicate: manufacturer name, product name, batch number, model, sampling date and name of the sampler. One bottle is used for inspection and the other bottle is kept for three months for future reference. 5.4 Hydrofluoric acid should be inspected by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer should ensure that each batch of products shipped meets the requirements of this standard.
If any of the indicators in the inspection results does not meet the requirements of this standard, resampling should be carried out from twice the amount of packaging units for re-inspection. If the re-inspection results even if one indicator does not meet the requirements of this standard, The entire batch of products is deemed to be unqualified. 5.5 Determine whether the inspection results meet the standards according to the rounding value comparison method specified in 5.2 of GB/T1250-1989. 6 Marking, packaging, transportation, storage
6.1 Industrial hydrofluoric acid packaging containers should have firm and clear markings, including: manufacturer name, factory address, product name, trademark, grade, model, net content, content The standard number is as well as the mark 14 "drugs" mark, mark 20 "corrosives" mark in GB190-1990, and mark 3 "upward" mark and mark 4 "heat-resistant" mark in GB191-1990. 6.2 Each batch of products leaving the factory should be accompanied by a quality certificate, which includes: manufacturer name, factory address, product name, trademark, grade, net content, batch number, model or production date, proof that the product quality complies with this standard and this standard serial number. 6.3 Industrial hydrofluoric acid is packaged in corrosion-resistant steel containers or plastic containers. For plastic container packaging, the thickness of the barrel should be more than 3mm, the blow molding thickness should be uniform, and it should have anti-aging and anti-freezing properties as well as compression, puncture resistance, and anti-friction functions that meet the regulations. Plastic buckets must not be made of any used plastic. The mouth of the barrel should be a small opening, which should be plugged tightly with a bowl-shaped cover. The threaded mouth, cover, gasket and other sealing parts should be in good condition, tightly screwed, and liquid-tight. The net weight of each piece shall not exceed 50kg. When transported by sea, the volume of hydrofluoric acid liquid shall not exceed 250L. Use container transportation. 6.4 Industrial hydrofluoric acid is transported by railway tank cars, boxcars, covered cars or ships. When transported by railway tank cars, the longitudinal middle part of the tank body should be painted with a black 300mm horizontal annular ribbon. When packed in plastic barrels, only the whole vehicle can be transported. It is strictly forbidden to be exposed to moisture, heat and rain during transportation. During shipment, it should be loaded and unloaded lightly, and collisions should be avoided. 6.5 Industrial hydrofluoric acid should be stored in a well-ventilated warehouse. The temperature in the warehouse should be kept below 30°C and the relative humidity below 85%. 7. Safety | The concentration is 1mg/m3. 7.2 It must be taken in a well-ventilated place or fume hood. Wear protective equipment of appropriate size. If you come into contact or suspect that you have come into contact with hydrofluoric acid, rinse with plenty of water and treat immediately. 479
6 Allowable difference
Take the arithmetic mean of the parallel measurement results as the measurement result. The absolute difference of the parallel measurement results is not greater than: 0.01% for superior products; 0.02% for equal products; 0.05% for qualified products. 5 Inspection rules
5.1 All items specified in this standard are factory inspection items. 5.2 Each batch of industrial hydrofluoric acid products shall not exceed 50t. 5.3 Sampling | |tt | When filling cans, each tank is a batch and one sample is taken.
5.3.2 Sampling method
Insert the plastic sampling tube into the bottom of the packaging container to extract the sample. For packaging of steel containers, samples should be taken from the upper and lower parts of each container. The sample taken should not be less than 500g, mix it evenly, put it into two clean, dry plastic containers, and seal it with wax. A label should be attached to the bottle, indicating: manufacturer name, product name, batch number, model, sampling date and name of the sampler. One bottle is used for inspection and the other bottle is kept for three months for future reference. 5.4 Hydrofluoric acid should be inspected by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer should ensure that each batch of products shipped meets the requirements of this standard.
If any of the indicators in the inspection results does not meet the requirements of this standard, resampling should be carried out from twice the amount of packaging units for re-inspection. If the re-inspection results even if one indicator does not meet the requirements of this standard, The entire batch of products is deemed to be unqualified. 5.5 Determine whether the inspection results meet the standards according to the rounding value comparison method specified in 5.2 of GB/T1250-1989. 6 Marking, packaging, transportation, storage
6.1 Industrial hydrofluoric acid packaging containers should have firm and clear markings, including: manufacturer name, factory address, product name, trademark, grade, model, net content, content The standard number is as well as the mark 14 "drugs" mark, mark 20 "corrosives" mark in GB190-1990, and mark 3 "upward" mark and mark 4 "heat-resistant" mark in GB191-1990. 6.2 Each batch of products leaving the factory should be accompanied by a quality certificate, which includes: manufacturer name, factory address, product name, trademark, grade, net content, batch number, model or production date, proof that the product quality complies with this standard and this standard serial number. 6.3 Industrial hydrofluoric acid is packaged in corrosion-resistant steel containers or plastic containers. For plastic container packaging, the thickness of the barrel should be more than 3mm, the blow molding thickness should be uniform, and it should have anti-aging and anti-freezing properties as well as compression, puncture resistance, and anti-friction functions that meet the regulations. Plastic buckets must not be made of any used plastic. The mouth of the barrel should be a small opening, which should be plugged tightly with a bowl-shaped cover. The threaded mouth, cover, gasket and other sealing parts should be in good condition, tightly screwed, and liquid-tight. The net weight of each piece does not exceed 50kg. When transported by sea, the volume of hydrofluoric acid liquid shall not exceed 250L. Use container transportation. 6.4 Industrial hydrofluoric acid is transported by railway tank cars, boxcars, covered cars or ships. When transported by railway tank cars, the longitudinal middle part of the tank body should be painted with a black 300mm horizontal annular ribbon. When packed in plastic barrels, only the whole vehicle can be transported. It is strictly forbidden to be exposed to moisture, heat and rain during transportation. During shipment, it should be loaded and unloaded lightly, and collisions should be avoided. 6.5 Industrial hydrofluoric acid should be stored in a well-ventilated warehouse. The temperature in the warehouse should be kept below 30°C and the relative humidity below 85%. 7. Safety | The concentration is 1mg/m3. 7.2 It must be taken in a well-ventilated place or fume hood. Wear protective equipment of appropriate size. If you come into contact or suspect that you have come into contact with hydrofluoric acid, rinse with plenty of water and treat immediately. 479
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