Some standard content:
Chemical Industry Standard of the People's Republic of China
1 Subject Content and Scope of Application
HG/T 2520-93
This standard specifies the technical requirements, test methods, inspection rules, and marking, packaging, transportation, and storage of industrial phosphorous acid. This standard applies to crystalline industrial phosphorous acid obtained by hydrolysis of phosphorus trichloride. This product is mainly used as a raw material for the production of phosphites, synthetic fibers, and organophosphorus pesticides, and is also used to produce an efficient water treatment agent ATMP. Molecular formula: H.PO3
Relative molecular mass: 82.00 (according to the international relative atomic mass of 1989)Cited standards
Dangerous goods packaging mark
GB 190
GB 191
Pictorial mark for packaging, storage and transportation
GB/T601
GB/T 602
GB/T 603
GB1250
Chemical reagentsPreparation of standard solutions for titration analysis (volume analysis)Chemical reagents
Preparation of standard solutions for impurity determination
Preparation of preparations and products used in chemical reagent test methodsExpression and determination methods of limit valuesGB/T 3049
GB/T 6678
GB/T 6682
Technical requirements
General method for determination of iron content in chemical products--Phenanthroline spectrophotometry
General principles for sampling of chemical products
Specifications and test methods for water used in analytical laboratories Appearance: white crystals.
Industrial phosphorous acid shall meet the requirements of the following table:
Main content (in H.PO4)
Chloride (in CI) content
Iron (Fe) content
Phosphate (in PO4,) content
Sulfate (in SO4,) content
Approved by the Ministry of Chemical Industry of the People's Republic of China on September 8, 1993 498
First-class product
Qualified product
Implemented on July 1, 1994
4 Test method
HG/T 2520-—93
The reagents and water used in this standard, unless otherwise specified, refer to analytical pure reagents and grade 3 water specified in GB/T6682. The standard titration solutions, impurity standard solutions, preparations and products used in the test, unless otherwise specified, are prepared in accordance with the provisions of GB/T601, GB/T602 and GB/T603. 4.1 Determination of main content
4.1.1 Summary of method
In the test solution, thymolphthalein is used as an indicator and titrated with sodium hydroxide standard titration solution. The phosphorous acid content is determined based on the consumption of sodium hydroxide standard titration solution. 4.1.2 Reagents and materialswww.bzxz.net
4.1.2.1 Sodium hydroxide (GB/T629) standard titration solution: c (NaOH) is about 1.0 mol/L; 4.1.2.2 Thymolphthalein (GB/T10728) indicator solution: 1 g/L. 4.1.3 Analysis steps
Weigh about 1g of sample, accurate to 0.0002g, place in a 250mL conical flask, add 80mL of water to dissolve, add 3 drops of thymol crisp indicator solution, and titrate with sodium hydroxide standard titration solution until the solution turns light blue, which is the end point. Perform a blank test at the same time. 4.1.4 Expression of analytical results
The main content (in terms of H:PO) (X,) expressed as mass percentage is calculated according to formula (1): X, = (V- Vo) ·c× 0. 041 00m
Wherein: V-the volume of standard sodium hydroxide solution consumed in titrating the test solution, mL, V.
-the volume of standard sodium hydroxide solution consumed in titrating the blank test solution, mL; the actual concentration of the standard sodium hydroxide solution, mol/L; C
-the mass of the sample, g;
0.041 00-
the mass of phosphorous acid equivalent to 1.00mL of standard sodium hydroxide solution c(NaOH)=1.000mol/L>, expressed in grams.
4.1.5 Allowable difference
The arithmetic mean of the parallel determination results shall be taken as the determination result. The absolute difference between two parallel determinations shall not exceed 0.2%. 4.2 Determination of fluoride content
4.2.1 Method summary
In the nitric acid medium, the nitrogen ions in the test solution react with the silver nitrate reagent to generate insoluble silver chloride. When the chloride ion content is low, the silver chloride is suspended for a certain period of time, making the solution turbid. The turbidity of the test solution is compared with that of the standard turbidity solution. 4.2.2 Reagents and materials
4.2.2.1 Nitric acid (GB/T626) solution: 1+3; 4.2.2.2 Silver nitrate (GB/T670) solution: 17g/L; 4.2.2.3 Chloride standard solution: 1mL solution contains 0.100mgCl. 4.2.3 Analysis steps
Weigh about 0.5g of the sample, accurate to 0.01g, place it in a 50mL colorimetric tube, add 20mL of water to dissolve, then add 2mL of nitric acid solution and 2mL of silver nitrate solution, dilute with water to the scale, and shake well. After standing for 10 minutes, the turbidity should not be greater than that of the standard turbidity solution. The standard turbidity solution is to use a pipette to transfer 0.5mL (equal product) and 1mL (qualified product) of chloride standard solution into 50mL colorimetric tubes respectively, and perform the same treatment as the test solution at the same time. 4.3 Determination of iron content
4.3.1 Summary of the method
Same as Article 2 of GB/T3049.
4.3.2 Reagents and materials
Same as Article 3 of GB/T3049.
4.3.3 Instruments and equipment
Same as Article 4 of GB/T3049.
4.3.4 Drawing of working curve
HG/T2520-93
Draw the working curve using a 3 cm absorption cell and the corresponding amount of iron standard solution according to Article 5.3 of GB/T3049. 4.3.5 Analysis steps
4.3.5.1 Preparation of test solution
Weigh about 2 g of sample to an accuracy of 0.01 g, place it in a 100 mL volumetric flask, and add 40 mL of water. 4.3.5.2 Preparation of blank test solution
Take 40 mL of water and place it in a 100 mL volumetric flask. 4.3.5.3 Determination
Take the test solution and blank test solution and perform the operation according to Article 5.4 of GB/T3049 starting from "add water to 60mL if necessary" to "measure the absorbance of the test solution". 4.3.6 Expression of analysis results
The iron (Fe) content (X,) expressed as mass percentage is calculated according to formula (2): Xz = m2 × m2 100
Wherein: m1—-the mass of iron in the test solution found from the working curve, g; m2———the mass of iron in the blank test solution found from the working curve, g; m——the mass of the sample, g.
4.3.7 Allowable difference
The arithmetic mean of the parallel determination results shall be taken as the determination result. The absolute difference between two parallel determinations shall not exceed 0.0003%. 4.4 Determination of phosphate content
4.4.1 Summary of the method
(2)
Test The phosphate ions in the solution react with the added magnesium mixture to form insoluble substances. When the phosphate ion content is low, the insoluble substances will be suspended for a certain period of time, making the solution turbid. The turbidity of the test solution is compared with that of the standard turbidity solution. 4.4.2 Reagents and materials
4.4.2.1 Ammonia solution (GB/T631): 2+3; 4.4.2.2 Hydrochloric acid solution (GB/T622): 1+4; 4.4.2.3 Magnesium mixture:
Preparation: Weigh 5.5g magnesium chloride (GB/T6 72) and 7g ammonium chloride (GB/T658) are placed in a 200mL beaker, and 65mL water is added to dissolve, and then 35mL nitrogen water (GB/T631) is added, and the mixture is left for 24 hours. If necessary, it is filtered. 4.4.2.4 Phosphate standard solution: 1mL of solution contains 0.100mg PO. 4.4.3 Analysis steps
4.4.3.1 Preparation of test solution
Weigh 2g of sample, accurate to 0.01g, and place in a 100mL volumetric flask, dilute to the mark with water, and shake well. 4.4.3 .2 Determination
Use a pipette to transfer 10mL of solution and place it in a 25mL colorimetric tube. Add 5mL of ammonia solution and 5mL of magnesium mixture, dilute with water to the mark, and shake. After 10 minutes, the turbidity should not be greater than that of the standard turbidity solution. The standard turbidity solution is to transfer 4mL (first-class product) and 12mL (qualified product) of phosphate standard solution, respectively, and place them in 25mL colorimetric tubes. After adjusting the pH to 2 with hydrochloric acid solution, perform the same treatment as the sample. 4.5 Determination of sulfate content
4.5.1 Method Summary
HG/T2520—93
In the hydrochloric acid medium, sulfate in the test solution reacts with the barium chloride reagent to form insoluble barium sulfate. When the sulfate ion content is low, barium sulfate will be suspended for a certain period of time, making the solution turbid. The turbidity of the test solution is compared with that of the standard turbidity solution. 4.5.2 Reagents and Materials
4.5.2.1 Hydrochloric acid (GB/T622) solution: 1+4; 4.5.2.2 Potassium sulfate (HG3—920) ethanol solution: 0.2g/I; 4.5.2.3 Barium chloride (GB/T652) solution: 250g/L; 4.5.2.4 Sulfate standard solution: 1mL solution contains 0.010mgSO4. Use a pipette to transfer 10mL of the sulfate standard solution prepared according to GB/T602, place it in a 100mL volumetric flask, dilute to the mark with water, and shake well. The solution is prepared before use. 4.5.3 Analysis steps
4.5.3.1 Preparation of test solution
Weigh about 1g of sample, accurate to 0.01g, place in a 25mL colorimetric tube, add 10mL water and 0.5mL hydrochloric acid solution, shake well. 4.5.3.2 Determination
Take 0.25ml potassium sulfate ethanol solution and 1mL barium chloride solution, mix and add to the test solution, dilute to the scale with water, shake well. After standing for 5min, the turbidity shall not be greater than the standard turbidity solution. The standard turbidity solution is to transfer 8ml (-quality) and 10mL (qualified product) of sulfate standard solution, respectively, into 25mL colorimetric tubes, and perform the same treatment as the sample at the same time.
5 Inspection rules
5.1 Industrial phosphorous acid shall be inspected by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer shall ensure that all industrial phosphorous acid products leaving the factory meet the requirements of this standard. Each batch of products leaving the factory should be accompanied by a quality certificate in a certain format. The content includes: manufacturer name, product name, grade, net weight, batch number or production date, proof that the product quality complies with this standard and the number of this standard. 5.2 The user has the right to accept the industrial phosphorous acid products received in accordance with the provisions of this standard. 5.3 Each batch of products shall not exceed 5t.
5.4 Determine the number of sampling units in accordance with the provisions of Article 6.6 of GB/T6678. When sampling, insert the sampler from the central vertical line of the packaging bag to 3/4 of the depth of the material layer to take samples. After quickly mixing the collected samples, reduce them to about 500g according to the quartering method, and immediately divide them into two clean and dry wide-mouth bottles with ground stoppers and seal them. Stick labels on the bottles, indicating: manufacturer name, product name, batch number, 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. 5.5 If one of the test results indicates that it does not meet the requirements of this standard, samples should be taken from twice the amount of packaging for re-verification. If even one of the indicators in the verification results does not meet the requirements of this standard, the entire batch of products cannot be accepted. 5.6 When the supply and demand parties have objections to the product quality, they should handle it in accordance with the provisions of the "Interim Measures for National Product Quality Arbitration Inspection". 5.7 The rounded value comparison method specified in GB1250 shall be used to determine whether the test results meet the standards. 6 Marking, packaging, transportation, storage
6.1 The packaging barrels of industrial phosphorous acid should be printed with firm and clear markings, including: manufacturer name, product name, trademark, grade, net weight, batch number or production date and this standard number, as well as the "corrosive product" mark specified in GB190 and the "moisture-sensitive" mark specified in GB191.
6.2 Industrial phosphorous acid is packaged in three layers. The inner packaging is a two-layer polyethylene plastic film bag with the specifications of 700mm×850mm or 500mm×500mm and a thickness of 0.1mm. The outer packaging is a sealed fully open iron drum or fiberboard drum with the specifications of $420mm×450mm or $300mm×400mm and a thickness of 1mm iron plate or 4mm fiberboard. The performance and inspection methods of each batch of packaging materials shall comply with relevant regulations. The net weight of each barrel of industrial phosphorous acid is 50kg or 25kg. 6.3. For the packaging of industrial phosphorous acid, the two layers of inner bags are tied manually with vinyl rope or rope of equivalent quality, or sealed with other equivalent methods. The iron drum or fiberboard drum is covered with a barrel cover, clamped with a clamping ring, and pinned with a T-shaped iron pin. 501
HG/T2520—93
6.4 Industrial phosphorous acid should be covered during transportation to prevent rain and moisture. It is strictly forbidden to mix it with alkalis and oxidizing substances. 6.5 Industrial phosphorous acid should be stored in a cool and dry place to prevent rain, sunlight, moisture and heat. It is strictly forbidden to mix it with alkalis and oxidizing substances. Additional remarks:
This standard is proposed by the Science and Technology Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Tianjin Chemical Research Institute of the Ministry of Chemical Industry. This standard was drafted by the Tianjin Chemical Research Institute of the Ministry of Chemical Industry, Jiangsu Yancheng Electrochemical Plant and Zhejiang Jiande Chemical Plant. The main drafters of this standard are Lu Siwei, Zheng Hannian, Lu Cui'e and Li Guangming. 5021mm. The outer packaging adopts a sealed fully open iron drum or fiberboard drum, with specifications and dimensions: $420mm×450mm or $300mm×400mm, and a thickness of 1mm iron plate or 4mm fiberboard. The performance and inspection methods of each batch of packaging materials shall comply with relevant regulations. The net weight of each barrel of industrial phosphorous acid is 50kg or 25kg. 6.3, for the packaging of industrial phosphorous acid, the two inner bags are tied manually with vinyl rope or rope of equivalent quality, or sealed with other equivalent methods. The iron drum or fiberboard drum is covered with a drum cover, clamped with a clamping ring, and pinned with a T-shaped iron pin. 501
HG/T2520—93
6.4 Industrial phosphorous acid should be covered during transportation to prevent rain and moisture. It is strictly forbidden to mix it with alkali and oxidizing items. 6.5 Industrial phosphorous acid should be stored in a cool and dry place to prevent rain, sunlight, moisture and heat. It is strictly forbidden to store with alkali and oxidizing materials. Additional remarks:
This standard is proposed by the Science and Technology Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of Tianjin Chemical Research Institute of the Ministry of Chemical Industry. This standard was drafted by Tianjin Chemical Research Institute of the Ministry of Chemical Industry, Jiangsu Yancheng Electrochemical Plant and Zhejiang Jiande Chemical Plant. The main drafters of this standard are Lu Siwei, Zheng Hannian, Lu Cui'e and Li Guangming. 5021mm. The outer packaging adopts a sealed fully open iron drum or fiberboard drum, with specifications and dimensions: $420mm×450mm or $300mm×400mm, and a thickness of 1mm iron plate or 4mm fiberboard. The performance and inspection methods of each batch of packaging materials shall comply with relevant regulations. The net weight of each barrel of industrial phosphorous acid is 50kg or 25kg. 6.3, for the packaging of industrial phosphorous acid, the two inner bags are tied manually with vinyl rope or rope of equivalent quality, or sealed with other equivalent methods. The iron drum or fiberboard drum is covered with a drum cover, clamped with a clamping ring, and pinned with a T-shaped iron pin. 501
HG/T2520—93
6.4 Industrial phosphorous acid should be covered during transportation to prevent rain and moisture. It is strictly forbidden to mix it with alkali and oxidizing items. 6.5 Industrial phosphorous acid should be stored in a cool and dry place to prevent rain, sunlight, moisture and heat. It is strictly forbidden to store with alkali and oxidizing materials. Additional remarks:
This standard is proposed by the Science and Technology Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of Tianjin Chemical Research Institute of the Ministry of Chemical Industry. This standard was drafted by Tianjin Chemical Research Institute of the Ministry of Chemical Industry, Jiangsu Yancheng Electrochemical Plant and Zhejiang Jiande Chemical Plant. The main drafters of this standard are Lu Siwei, Zheng Hannian, Lu Cui'e and Li Guangming. 502
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