Some standard content:
HG/T2832—-1997
The superior products of this standard are equivalent to the American standard ANSI/AWWAB703:1989 "Fluorosilicic Acid". Its superior products have reached the international advanced level, and the first-class products have reached the international general level. The main technical differences between this standard and the American standard are as follows: 1 The products are divided into three grades according to the actual situation in my country. 2 Two indicators of free fluorine and copper required by users are added. 3 The determination of fluosilicic acid content uses phenolic acid as an indicator instead of bromothymol blue as an indicator in the American standard. 4 The determination of free fluorine and copper content adopts the classic method verified by many years of use. This standard is proposed by the Technical Supervision 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. Drafting units of this standard: Tianjin Chemical Research Institute of the Ministry of Chemical Industry, Yunnan Kunyang Phosphate Fertilizer Plant. The main drafters of this standard: Yao Jinjuan, Xiang Rongli, Zhou Jiguang This standard is entrusted to the technical unit responsible for the standardization of inorganic salt products of the Ministry of Chemical Industry for interpretation. 525
1 Scope
Chemical Industry Standard of the People's Republic of China
Industrial Fluosilicic Acid
Fluosilicic Acid for Industrial UseHG/T 2832-1997
This standard specifies the requirements, sampling, test methods, marking, packaging, transportation, storage and safety requirements for industrial fluosilicic acid. This standard applies to industrial fluosilicic acid made from silicon tetrafluoride gas produced as a by-product in the production of wet phosphate fertilizer and wet phosphoric acid by water circulation absorption. : This product is mainly used as an additive in the wet process and smelting industry and as a raw material for the production of fluoride salt series chemical products. Molecular formula: H, SiF.
Relative molecular mass: 144.09 (according to the international relative atomic mass in 1993) 2
Cited Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard was published, the versions shown were all valid. All standards are subject to revision. Parties using this standard should explore the possibility of using the latest version of the following standards. GB 190--19902
Dangerous Goods Packaging Marking
GB 191—1990
Packaging Storage and Transportation Pictorial Marking
GB/T 601—1988
GB/T 602—1988
GB/T 603--1988
GB/T 1250—1989
GB/T 6678—1986
GB/T 6682--1992
3 Requirements
Preparation of standard solutions for titration analysis (volume analysis) of chemical reagents Preparation of standard solutions for determination of impurities of chemical reagents (negISO6353-1:1982) Preparation of preparations and products used in test methods for chemical reagents (neqISO6353-1:1982) Expression and determination methods of limit values General rules for sampling of chemical products
Specifications and test methods for water used in analytical laboratories (eqvISO3696:1987) 3.1 Appearance: colorless liquid or light-colored liquid. 3.2 Industrial fluorosilicic acid shall meet the requirements of Table 1. Table 1 Requirements
Superior products
Fluorosilicic acid (H, SiF) content
Free fluorine (F) content
Copper (Cu) content
Heavy metal (Pb) content
4 Sampling
Each batch of products shall not exceed 60t.
20.0~30.0
Approved by the Ministry of Chemical Industry of the People's Republic of China on February 4, 1997526
First-class products
Qualified products
Implemented on October 1, 1997
HG/T 2832—1997
4.2 Determine the number of sampling units according to the provisions of 6.6 of GB/T6678. When sampling in barrels, mix the products in the barrel, insert the plastic sampler to 3/4 of the barrel, and seal the upper end after the sample is full, and take it out. The mass of each barrel shall not be less than 100. The total sampling volume shall not be less than 500g. When transporting in a tank truck or storage tank, use a plastic sampling bottle to take out equal amounts of samples from the top, middle and bottom of different depths, mix them evenly, and the total sample volume shall not be less than 500g. The sampled samples are divided into two clean and dry plastic bottles with stoppers and sealed. Labels are attached to the bottles, indicating: manufacturer name, product name, grade, batch number, sampling date and name of the sampler. One bottle is used as a laboratory sample, and the other bottle is kept for three months for reference. 4.3 If one of the test results does not meet the requirements of this standard, re-sampling should be carried out from twice the amount of packaging for verification. Even if only one of the verification results does not meet the requirements of this standard, the entire batch of products is unqualified. 5 Test method
5.1 Determine whether the test results meet the standard by the rounded value comparison method specified in 5.2 of GB/T1250. 5.2 The reagents and water used in this standard, unless otherwise specified, refer to analytically 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.
5.3 Determination of Fluorosilicic Acid Content
5.3.1 Summary of Method
Fluorosilicic acid reacts with potassium nitrate to generate potassium fluosilicate precipitate and nitric acid. First, the nitric acid and other acids (a trace amount of HF) generated by the reaction are titrated with a standard sodium hydroxide titration solution at room temperature. Then, the hydrofluoric acid generated by boiling hydrolysis is titrated. The content of fluosilicic acid is calculated based on the amount of the standard sodium hydroxide titration solution used in the titration of the latter. 5.3.2 Reagents and materials
5.3.2.1 Saturated potassium nitrate solution;
5.3.2.2 Standard sodium hydroxide titration solution: c(NaOH) about 0.5 mol/L; 5.3, 2.3 Phenolic acid indicator solution: 10 g/L.
5.3.3 Analysis steps
Use a weighing bottle to weigh about 2 g of the sample (accurate to 0.0002 g), place it in a 250 mL conical flask, add 10 mL of saturated potassium nitrate solution and 10 mL of water, place it in a refrigerator for 30 min, take it out and add 3 drops of phenolic acid indicator solution, titrate with sodium hydroxide standard titration solution until the red color remains unchanged for 30 seconds, record the volume consumed (V.), heat the solution to boiling, continue to titrate with sodium hydroxide standard titration solution until the stable red color is the end point, and record the volume consumed (V2). 5.3.4 Expression of analytical results
The content X of fluorosilicic acid (H2SiF.) expressed as mass percentage is calculated according to the formula (1): X = (VV)c×0.03602×100
_ 3.602 × cX (V2 V.)
Wherein: V,-the volume of sodium hydroxide standard titration solution consumed in titration to the first endpoint, mL; V2-the volume of sodium hydroxide standard titration solution consumed in titration to the second endpoint, mL; c——the actual concentration of sodium hydroxide standard titration solution, mol/L; (1)
Mass of sample, g;
The mass of fluorosilicic acid (0.03602-
expressed in grams) equivalent to 1.00mL of sodium hydroxide standard titration solution [c(NaOH)=1.000mol/L].
5.3.5 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.15%. 5.4 Determination of free fluorine content
5.4.1 Method summary
HG/T 2832--1997
After the sample is precipitated with potassium nitrate, the pH value of the filtrate is adjusted to 5.5-6.0. The saturated calomel electrode is used as the reference electrode, and the electrode potential of the solution is directly measured with a fluoride ion selective electrode. The fluorine content is calculated using the standard curve method. 5.4.2 Reagents and materials
5.4.2.1 Nitric acid solution: 1+15;
5.4.2.2 Sodium hydroxide solution: 200g/L; 5.4.2.3 Saturated potassium nitrate solution;
5.4.2.4 Citric acid-sodium citrate buffer solution (pH5.56.0); Weigh 270g sodium citrate dihydrate and 24g citric acid monohydrate, dissolve in water, dilute to 1000mL, and shake well. 5.4.2.5 Fluorine standard solution: 1 ml of solution contains 0.1 mg F; 5.4.2.6 Bromocresol green indicator solution: 1 g/L; 5.4.3 Instruments and equipment
5.4.3.1 Fluoride ion selective electrode;
5.4.3.2 Saturated calomel electrode;
5.4.3.3 Potentiometer: accuracy 2 mV/grid, range -500 mV~+500 mV; 5.4.3.4 Electromagnetic stirrer.
5.4.4 Analysis steps
5.4.4.1 Preparation of test solution A
Weigh about 5g of sample (accurate to 0.0002g), place it in a 150ml plastic beaker, add 20mL of saturated potassium nitrate solution, and stir well with a plastic stick. Place it in the refrigerator for 20min, and filter it with medium-speed qualitative filter paper. Wash the precipitate with 20mL of saturated potassium nitrate solution three times, and put the filtrate and washing solution in a 100mlL volumetric flask, dilute with water to the scale, and shake well. Keep this solution for the determination of fluorine, copper, and heavy metal content.
5.4.4.2 Drawing of working curve
Use a pipette to transfer 1.00ml, 2.00ml3.00mL, 5.00mL, 7.00mL, and 10.00mL of fluorine standard solution, place them in 50mL volumetric flasks respectively, add 1mL of saturated potassium nitrate solution and 2 drops of bromocresol green indicator solution, neutralize with sodium hydroxide solution until the solution turns blue, and then adjust the solution to yellow with nitric acid solution. Add 20mL of citric acid-sodium citrate buffer solution, dilute to the mark with water, and shake well. Pour into a dry 50mL beaker, insert a fluoride ion selective electrode and a saturated calomel electrode, and measure the potential value at equilibrium while stirring with a magnetic stirrer.
Use the mass of fluorine as the horizontal axis and the corresponding potential value as the vertical axis to draw a working curve on a semi-logarithmic coordinate paper. 5.4.4.3 Determination
Use a pipette to transfer 2.0ml of test solution A (5.4.4.1) into a 50mL volumetric flask, and add 2 drops of bromocresol green indicator solution. The following operations are the same as those in 5.1.4.2, starting from "neutralize with sodium hydroxide solution until the solution turns blue" to "measure the potential value at equilibrium". According to the measured potential value, check the working curve to obtain the milligrams of fluorine. 5.4.4.4.4 Expression of analysis results
The fluorine (F) content X2 expressed as mass percentage is calculated according to formula (2): X, -mi X 10-3
m×100
Wherein: m—fluorine content obtained from the working curve, mg; m—mass of the sample, g.
5.4.4.5 Permissible difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.05%. 5.5 Determination of copper content
5.5.1 Summary of method
HG/T 2832--1997
After the sample is precipitated with saturated potassium nitrate to separate fluorosilicic acid, copper reacts with the copper reagent at pH=9 to form a brown complex. It is extracted with ethyl acetate to improve the sensitivity of the method and its content is determined by spectrophotometry. 5.5.2 Reagents and materials
5.5.2.1 Ammonia water;
5.5.2.2 Ethyl acetate;
Nitric acid solution: 1+1;
Ethylenediaminetetraacetic acid disodium solution: 50g/L; Potassium nitrate saturated solution;
Citric acid solution: 100g/L;
Sodium diethylaminodithiocarbamate (copper reagent) solution: 1.g/L; Copper standard solution: 1 ml solution contains 5μgCu; 5.5.2.8
Use a pipette to take 5ml of the copper standard solution prepared according to GB/T602, place it in a 100ml volumetric flask, dilute it to the mark with water, and shake it. This solution is prepared before use.
5.5.2.9 Phenolyl indicator solution: 10g/L.
5.5.3 Instruments and equipment
5.5.3.1 Spectrophotometer: with 3cm absorption cell; 5.5.3.2 Separating funnel: capacity 125mL. 5.5.4 Analysis steps
5.5.4.1 Drawing of working curve
Use a pipette to take 0mL, 1.00mL, 2.00mL, 3.00mL, 4.00mL, and 5.00mL of copper standard solution and place them in the separating funnel respectively, add 40mL of water, 5mL of disodium ethylenediaminetetraacetic acid solution, 10mL of citric acid solution and 1 drop of phenolic acid indicator solution, adjust to red with ammonia water, add 5mL of copper reagent, shake, let stand for 5min, add 10mL of ethyl acetate, and shake for 1min. After separation, put the lower aqueous phase into another separating funnel, add 5mL of copper reagent, shake, and then add 5mL of ethyl acetate for the second extraction, and discard the aqueous phase. Use filter paper to absorb the water attached to the necks of the two separating funnels, combine the organic phases, and put them into a 25mL colorimetric tube. Wash the separating funnel with ethyl acetate, add the washing liquid to the colorimetric tube, and dilute it to the scale with ethyl acetate and shake it well. Use a 3cm absorption cell and ethyl acetate as a reference at a wavelength of 430nm to measure the absorbance of the solution.
Use the mass of copper as the horizontal axis and the corresponding absorbance as the vertical axis to draw a working curve. 5.5.4.2 Determination
Use a pipette to transfer 50ml of test solution A (5.4.4.1) and place it in a separating funnel. Take another separating funnel and add 40ml of water for a blank test. The following operations are based on 5.5.4.1, starting from "adding 5mL of disodium ethylenediaminetetraacetic acid solution" to "measuring the absorbance of the solution".
Subtract the absorbance of the blank test solution from the measured absorbance of the test solution, and find the corresponding copper amount from the standard curve. 5.5.5 Expression of analysis results
The copper (Cu) content X expressed as mass percentage is calculated according to formula (3): X = mX10 6
m×100
2 ×mi × 10-4
The amount of copper in the test solution obtained from the working curve, ug; where: m-
-mass of the sample, g.
5.5.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.00005%. . (3)
5.6 Determination of heavy metal content
5.6.1 Summary of method
HG/T2832—1997
Under weak acidic conditions, the heavy metal ions in the sample react with hydrogen sulfide to produce brown-black color, which is compared with the standard. 5.6.2 Reagents and materials
5.6.2.1 Ammonia solution: 1+3;
5.6.2.2 Hydrochloric acid solution: c(HCI) about 0.1 mol/L, 5.6.2.3 Saturated hydrogen sulfide water;
5.6.2.4 Lead standard solution: 1 mL of solution contains 0.1 mg Pb. 5.6.3 Analysis steps
Use a pipette to transfer 10 mL of test solution A (5.4.4.1) into a 50 mL colorimetric tube, and adjust the pH to 3-4 with ammonia or hydrochloric acid solution (pH test paper test). Add 10 mL of saturated hydrogen sulfide water, dilute to the mark with water, shake the hook, and place in a dark place for 10 minutes. Its color should not be darker than the standard colorimetric solution.
The standard colorimetric solution is 1 mL of lead standard solution, which is treated in the same way as the test solution. 6 Marking, packaging, transportation, storage
6.1 The packaging of industrial fluosilicic acid should be firmly and clearly marked, including: manufacturer name, factory address, product name, trademark, grade, net weight, batch number or production date, this standard number and the "toxic" mark and "corrosive product" mark specified in GB190 and the "upward" mark specified in GB191.
6.2 Each batch of industrial fluosilicic acid shipped out of the factory should be accompanied by a quality certificate. The content includes: manufacturer name, factory address, product name, trademark, grade, net weight, batch number or production date, proof that the product quality meets this standard and this standard number. 6.3 When industrial fluosilicic acid is packaged in rubber or plastic barrels. It should be placed in a sturdy wooden box with a non-combustible material lining inside the box and reinforced with iron sheets or wire outside the box. The net weight of each barrel is 20kg or 40kg. It can also be transported by tank truck. 6.4 The inner cover of the industrial fluosilicic acid packaging barrel is tightly closed and the outer cover is tightened. 6.5 Industrial fluorosilicic acid should be transported in a dedicated vehicle and the tightness of the lid should be checked frequently. 6.6 Industrial fluorosilicic acid should be stored in a low-temperature, ventilated and dry warehouse. The warehouse temperature should not exceed 30°C. It is strictly forbidden to store it together with alkalis and other easily corrosive items.
7 Safety requirements
Industrial fluorosilicic acid is a strong acid that is toxic and corrosive. Protective clothing, gloves and protective glasses must be worn during storage and use. 530100mL fluorine standard solution, place in 50mL volumetric flasks, add 1mL potassium nitrate saturated solution and 2 drops of bromocresol green indicator solution, neutralize with sodium hydroxide solution until the solution turns blue, and then adjust the solution to yellow with nitric acid solution. Add 20mL citric acid-sodium citrate buffer solution, dilute with water to the scale, and shake well. Pour into a dry 50mL beaker, insert the fluoride ion selective electrode and saturated calomel electrode, and measure the potential value at equilibrium under continuous stirring with a magnetic stirrer.
With the mass of fluorine as the horizontal axis and the corresponding potential value as the vertical axis, draw a working curve on semi-logarithmic coordinate paper. 5.4.4.3 Determination
Use a pipette to transfer 2.0mlL test solution A (5.4.4.1) into a 50mL volumetric flask and add 2 drops of bromocresol green indicator solution. The following operations are the same as 5.1.4.2, starting from "neutralize with sodium hydroxide solution until the solution turns blue" to "measure the potential value at equilibrium". According to the measured potential value, the milligrams of fluorine are obtained by checking the working curve. 5.4.4.4 Expression of analysis resultsWww.bzxZ.net
The fluorine (F) content X2 expressed as mass percentage is calculated according to formula (2): X, -mi X 10-3
m×100
Wherein: m—the amount of fluorine obtained from the working curve, mg; m—the mass of the sample, g.
5.4.4.5 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.05%. 5.5 Determination of copper content
5.5.1 Summary of method
HG/T 2832--1997
After the sample is precipitated with saturated potassium nitrate to separate fluorosilicic acid, copper reacts with the copper reagent at pH=9 to form a brown complex. Extract with ethyl acetate to improve the sensitivity of the method, and determine its content by spectrophotometry. 5.5.2 Reagents and materials
5.5.2.1 Ammonia water;
5.5.2.2 Ethyl acetate;
Nitric acid solution: 1+1;
Disodium ethylenediaminetetraacetic acid solution: 50g/L; Saturated potassium nitrate solution;
Citric acid solution: 100g/L;
Sodium diethylaminodithiocarbamate (copper reagent) solution: 1.g/L; Copper standard solution: 1ml solution contains 5μgCu; 5.5.2.8
Use a pipette to transfer 5ml of the copper standard solution prepared according to GB/T602 into a 100ml volumetric flask, dilute with water to the mark, and shake to hook. This solution is prepared before use.
5.5.2.9 Phenolyl indicator solution: 10g/L.
5.5.3 Instruments and equipment
5.5.3.1 Spectrophotometer: with 3cm absorption cell; 5.5.3.2 Separating funnel: capacity 125mL. 5.5.4 Analysis steps
5.5.4.1 Drawing of working curve
Use a pipette to take 0mL, 1.00mL, 2.00mL, 3.00mL, 4.00mL, and 5.00mL of copper standard solution and place them in the separating funnel respectively, add 40mL of water, 5mL of disodium ethylenediaminetetraacetic acid solution, 10mL of citric acid solution and 1 drop of phenolic acid indicator solution, adjust to red with ammonia water, add 5mL of copper reagent, shake, let stand for 5min, add 10mL of ethyl acetate, and shake for 1min. After separation, put the lower aqueous phase into another separating funnel, add 5mL of copper reagent, shake, and then add 5mL of ethyl acetate for the second extraction, and discard the aqueous phase. Use filter paper to absorb the water attached to the necks of the two separating funnels, combine the organic phases, and put them into a 25mL colorimetric tube. Wash the separating funnel with ethyl acetate, add the washing liquid to the colorimetric tube, and dilute it to the scale with ethyl acetate and shake it well. Use a 3cm absorption cell and ethyl acetate as a reference at a wavelength of 430nm to measure the absorbance of the solution.
Use the mass of copper as the horizontal axis and the corresponding absorbance as the vertical axis to draw a working curve. 5.5.4.2 Determination
Use a pipette to transfer 50ml of test solution A (5.4.4.1) and place it in a separating funnel. Take another separating funnel and add 40ml of water for a blank test. The following operations are based on 5.5.4.1, starting from "adding 5mL of disodium ethylenediaminetetraacetic acid solution" to "measuring the absorbance of the solution".
Subtract the absorbance of the blank test solution from the measured absorbance of the test solution, and find the corresponding copper amount from the standard curve. 5.5.5 Expression of analysis results
The copper (Cu) content X expressed as mass percentage is calculated according to formula (3): X = mX10 6
m×100
2 ×mi × 10-4
The amount of copper in the test solution obtained from the working curve, ug; where: m-
-mass of the sample, g.
5.5.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.00005%. . (3)
5.6 Determination of heavy metal content
5.6.1 Summary of method
HG/T2832—1997
Under weak acidic conditions, the heavy metal ions in the sample react with hydrogen sulfide to produce brown-black color, which is compared with the standard. 5.6.2 Reagents and materials
5.6.2.1 Ammonia solution: 1+3;
5.6.2.2 Hydrochloric acid solution: c(HCI) about 0.1 mol/L, 5.6.2.3 Saturated hydrogen sulfide water;
5.6.2.4 Lead standard solution: 1 mL of solution contains 0.1 mg Pb. 5.6.3 Analysis steps
Use a pipette to transfer 10 mL of test solution A (5.4.4.1) into a 50 mL colorimetric tube, and adjust the pH to 3-4 with ammonia or hydrochloric acid solution (pH test paper test). Add 10 mL of saturated hydrogen sulfide water, dilute to the mark with water, shake the hook, and place in a dark place for 10 minutes. Its color should not be darker than the standard colorimetric solution.
The standard colorimetric solution is 1 mL of lead standard solution, which is treated in the same way as the test solution. 6 Marking, packaging, transportation, storage
6.1 The packaging of industrial fluosilicic acid should be firmly and clearly marked, including: manufacturer name, factory address, product name, trademark, grade, net weight, batch number or production date, this standard number and the "toxic" mark and "corrosive product" mark specified in GB190 and the "upward" mark specified in GB191.
6.2 Each batch of industrial fluosilicic acid shipped out of the factory should be accompanied by a quality certificate. The content includes: manufacturer name, factory address, product name, trademark, grade, net weight, batch number or production date, proof that the product quality meets this standard and this standard number. 6.3 When industrial fluosilicic acid is packaged in rubber or plastic barrels. It should be placed in a sturdy wooden box with a non-combustible material lining inside the box and reinforced with iron sheets or wire outside the box. The net weight of each barrel is 20kg or 40kg. It can also be transported by tank truck. 6.4 The inner cover of the industrial fluosilicic acid packaging barrel is tightly closed and the outer cover is tightened. 6.5 Industrial fluorosilicic acid should be transported in a dedicated vehicle and the tightness of the lid should be checked frequently. 6.6 Industrial fluorosilicic acid should be stored in a low-temperature, ventilated and dry warehouse. The warehouse temperature should not exceed 30°C. It is strictly forbidden to store it together with alkalis and other easily corrosive items.
7 Safety requirements
Industrial fluorosilicic acid is a strong acid that is toxic and corrosive. Protective clothing, gloves and protective glasses must be worn during storage and use. 530100mL fluorine standard solution, place in 50mL volumetric flasks, add 1mL potassium nitrate saturated solution and 2 drops of bromocresol green indicator solution, neutralize with sodium hydroxide solution until the solution turns blue, and then adjust the solution to yellow with nitric acid solution. Add 20mL citric acid-sodium citrate buffer solution, dilute with water to the scale, and shake well. Pour into a dry 50mL beaker, insert the fluoride ion selective electrode and saturated calomel electrode, and measure the potential value at equilibrium under continuous stirring with a magnetic stirrer.
With the mass of fluorine as the horizontal axis and the corresponding potential value as the vertical axis, draw a working curve on semi-logarithmic coordinate paper. 5.4.4.3 Determination
Use a pipette to transfer 2.0mlL test solution A (5.4.4.1) into a 50mL volumetric flask and add 2 drops of bromocresol green indicator solution. The following operations are the same as 5.1.4.2, starting from "neutralize with sodium hydroxide solution until the solution turns blue" to "measure the potential value at equilibrium". According to the measured potential value, the milligrams of fluorine are obtained by checking the working curve. 5.4.4.4 Expression of analysis results
The fluorine (F) content X2 expressed as mass percentage is calculated according to formula (2): X, -mi X 10-3
m×100
Wherein: m—the amount of fluorine obtained from the working curve, mg; m—the mass of the sample, g.
5.4.4.5 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.05%. 5.5 Determination of copper content
5.5.1 Summary of method
HG/T 2832--1997
After the sample is precipitated with saturated potassium nitrate to separate fluorosilicic acid, copper reacts with the copper reagent at pH=9 to form a brown complex. Extract with ethyl acetate to improve the sensitivity of the method, and determine its content by spectrophotometry. 5.5.2 Reagents and materials
5.5.2.1 Ammonia water;
5.5.2.2 Ethyl acetate;
Nitric acid solution: 1+1;
Disodium ethylenediaminetetraacetic acid solution: 50g/L; Saturated potassium nitrate solution;
Citric acid solution: 100g/L;
Sodium diethylaminodithiocarbamate (copper reagent) solution: 1.g/L; Copper standard solution: 1ml solution contains 5μgCu; 5.5.2.8
Use a pipette to transfer 5ml of the copper standard solution prepared according to GB/T602 into a 100ml volumetric flask, dilute with water to the mark, and shake to hook. This solution is prepared before use.
5.5.2.9 Phenolyl indicator solution: 10g/L.
5.5.3 Instruments and equipment
5.5.3.1 Spectrophotometer: with 3cm absorption cell; 5.5.3.2 Separating funnel: capacity 125mL. 5.5.4 Analysis steps
5.5.4.1 Drawing of working curve
Use a pipette to take 0mL, 1.00mL, 2.00mL, 3.00mL, 4.00mL, and 5.00mL of copper standard solution and place them in the separating funnel respectively, add 40mL of water, 5mL of disodium ethylenediaminetetraacetic acid solution, 10mL of citric acid solution and 1 drop of phenolic acid indicator solution, adjust to red with ammonia water, add 5mL of copper reagent, shake, let stand for 5min, add 10mL of ethyl acetate, and shake for 1min. After separation, put the lower aqueous phase into another separating funnel, add 5mL of copper reagent, shake, and then add 5mL of ethyl acetate for the second extraction, and discard the aqueous phase. Use filter paper to absorb the water attached to the necks of the two separating funnels, combine the organic phases, and put them into a 25mL colorimetric tube. Wash the separating funnel with ethyl acetate, add the washing liquid to the colorimetric tube, and dilute it to the scale with ethyl acetate and shake it well. Use a 3cm absorption cell and ethyl acetate as a reference at a wavelength of 430nm to measure the absorbance of the solution.
Use the mass of copper as the horizontal axis and the corresponding absorbance as the vertical axis to draw a working curve. 5.5.4.2 Determination
Use a pipette to transfer 50ml of test solution A (5.4.4.1) and place it in a separating funnel. Take another separating funnel and add 40ml of water for a blank test. The following operations are based on 5.5.4.1, starting from "adding 5mL of disodium ethylenediaminetetraacetic acid solution" to "measuring the absorbance of the solution".
Subtract the absorbance of the blank test solution from the measured absorbance of the test solution, and find the corresponding copper amount from the standard curve. 5.5.5 Expression of analysis results
The copper (Cu) content X expressed as mass percentage is calculated according to formula (3): X = mX10 6
m×100
2 ×mi × 10-4
The amount of copper in the test solution obtained from the working curve, ug; where: m-
-mass of the sample, g.
5.5.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.00005%. . (3)
5.6 Determination of heavy metal content
5.6.1 Summary of method
HG/T2832—1997
Under weak acidic conditions, the heavy metal ions in the sample react with hydrogen sulfide to produce brown-black color, which is compared with the standard. 5.6.2 Reagents and materials
5.6.2.1 Ammonia solution: 1+3;
5.6.2.2 Hydrochloric acid solution: c(HCI) about 0.1 mol/L, 5.6.2.3 Saturated hydrogen sulfide water;
5.6.2.4 Lead standard solution: 1 mL of solution contains 0.1 mg Pb. 5.6.3 Analysis steps
Use a pipette to transfer 10 mL of test solution A (5.4.4.1) into a 50 mL colorimetric tube, and adjust the pH to 3-4 with ammonia or hydrochloric acid solution (pH test paper test). Add 10 mL of saturated hydrogen sulfide water, dilute to the mark with water, shake the hook, and place in a dark place for 10 minutes. Its color should not be darker than the standard colorimetric solution.
The standard colorimetric solution is 1 mL of lead standard solution, which is treated in the same way as the test solution. 6 Marking, packaging, transportation, storage
6.1 The packaging of industrial fluosilicic acid should be firmly and clearly marked, including: manufacturer name, factory address, product name, trademark, grade, net weight, batch number or production date, this standard number and the "toxic" mark and "corrosive product" mark specified in GB190 and the "upward" mark specified in GB191.
6.2 Each batch of industrial fluosilicic acid shipped out of the factory should be accompanied by a quality certificate. The content includes: manufacturer name, factory address, product name, trademark, grade, net weight, batch number or production date, proof that the product quality meets this standard and this standard number. 6.3 When industrial fluosilicic acid is packaged in rubber or plastic barrels. It should be placed in a sturdy wooden box with a non-combustible material lining inside the box and reinforced with iron sheets or wire outside the box. The net weight of each barrel is 20kg or 40kg. It can also be transported by tank truck. 6.4 The inner cover of the industrial fluosilicic acid packaging barrel is tightly closed and the outer cover is tightened. 6.5 Industrial fluorosilicic acid should be transported in a dedicated vehicle and the tightness of the lid should be checked frequently. 6.6 Industrial fluorosilicic acid should be stored in a low-temperature, ventilated and dry warehouse. The warehouse temperature should not exceed 30°C. It is strictly forbidden to store it together with alkalis and other easily corrosive items.
7 Safety requirements
Industrial fluorosilicic acid is a strong acid that is toxic and corrosive. Protective clothing, gloves and protective glasses must be worn during storage and use. 5301 Method Summary
HG/T 2832--1997
After the sample is precipitated with saturated potassium nitrate to separate fluorosilicic acid, copper reacts with copper reagent to form a brown complex at pH = 9. It is extracted with ethyl acetate to improve the sensitivity of the method, and its content is determined by spectrophotometry. 5.5.2 Reagents and materials
5.5.2.1 Ammonia water;
5.5.2.2 Ethyl acetate;
Nitric acid solution: 1+1;
Ethylenediaminetetraacetic acid disodium solution: 50g/L; Saturated potassium nitrate solution;
Citric acid solution: 100g/L;
Sodium diethylaminodithiocarbamate (copper reagent) solution: 1.g/L; Copper standard solution: 1 ml solution contains 5μgCu; 5.5.2.8
Use a pipette to take 5ml of the copper standard solution prepared according to GB/T602, place it in a 100ml volumetric flask, dilute it to the mark with water, and shake it. This solution is prepared before use.
5.5.2.9 Phenolyl indicator solution: 10g/L.
5.5.3 Instruments and equipment
5.5.3.1 Spectrophotometer: with 3cm absorption cell; 5.5.3.2 Separating funnel: capacity 125mL. 5.5.4 Analysis steps
5.5.4.1 Drawing of working curve
Use a pipette to take 0mL, 1.00mL, 2.00mL, 3.00mL, 4.00mL, and 5.00mL of copper standard solution and place them in the separating funnel respectively, add 40mL of water, 5mL of disodium ethylenediaminetetraacetic acid solution, 10mL of citric acid solution and 1 drop of phenolic acid indicator solution, adjust to red with ammonia water, add 5mL of copper reagent, shake, let stand for 5min, add 10mL of ethyl acetate, and shake for 1min. After separation, put the lower aqueous phase into another separating funnel, add 5mL of copper reagent, shake, and then add 5mL of ethyl acetate for the second extraction, and discard the aqueous phase. Use filter paper to absorb the water attached to the necks of the two separating funnels, combine the organic phases, and put them into a 25mL colorimetric tube. Wash the separating funnel with ethyl acetate, add the washing liquid to the colorimetric tube, and dilute it to the scale with ethyl acetate and shake it well. Use a 3cm absorption cell and ethyl acetate as a reference at a wavelength of 430nm to measure the absorbance of the solution.
Use the mass of copper as the horizontal axis and the corresponding absorbance as the vertical axis to draw a working curve. 5.5.4.2 Determination
Use a pipette to transfer 50ml of test solution A (5.4.4.1) and place it in a separating funnel. Take another separating funnel and add 40ml of water for a blank test. The following operations are based on 5.5.4.1, starting from "adding 5mL of disodium ethylenediaminetetraacetic acid solution" to "measuring the absorbance of the solution".
Subtract the absorbance of the blank test solution from the measured absorbance of the test solution, and find the corresponding copper amount from the standard curve. 5.5.5 Expression of analysis results
The copper (Cu) content X expressed as mass percentage is calculated according to formula (3): X = mX10 6
m×100
2 ×mi × 10-4
The amount of copper in the test solution obtained from the working curve, ug; where: m-
-mass of the sample, g.
5.5.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.00005%. . (3)
5.6 Determination of heavy metal content
5.6.1 Summary of method
HG/T2832—1997
Under weak acidic conditions, the heavy metal ions in the sample react with hydrogen sulfide to produce brown-black color, which is compared with the standard. 5.6.2 Reagents and materials
5.6.2.1 Ammonia solution: 1+3;
5.6.2.2 Hydrochloric acid solution: c(HCI) about 0.1 mol/L, 5.6.2.3 Saturated hydrogen sulfide water;
5.6.2.4 Lead standard solution: 1 mL of solution contains 0.1 mg Pb. 5.6.3 Analysis steps
Use a pipette to transfer 10 mL of test solution A (5.4.4.1) into a 50 mL colorimetric tube, and adjust the pH to 3-4 with ammonia or hydrochloric acid solution (pH test paper test). Add 10 mL of saturated hydrogen sulfide water, dilute to the mark with water, shake the hook, and place in a dark place for 10 minutes. Its color should not be darker than the standard colorimetric solution.
The standard colorimetric solution is 1 mL of lead standard solution, which is treated in the same way as the test solution. 6 Marking, packaging, transportation, storage
6.1 The packaging of industrial fluosilicic acid should be firmly and clearly marked, including: manufacturer name, factory address, product name, trademark, grade, net weight, batch number or production date, this standard number and the "toxic" mark and "corrosive product" mark specified in GB190 and the "upward" mark specified in GB191.
6.2 Each batch of industrial fluosilicic acid shipped out of the factory should be accompanied by a quality certificate. The content includes: manufacturer name, factory address, product name, trademark, grade, net weight, batch number or production date, proof that the product quality meets this standard and this standard number. 6.3 When industrial fluosilicic acid is packaged in rubber or plastic barrels. It should be placed in a sturdy wooden box with a non-combustible material lining inside the box and reinforced with iron sheets or wire outside the box. The net weight of each barrel is 20kg or 40kg. It can also be transported by tank truck. 6.4 The inner cover of the industrial fluosilicic acid packaging barrel is tightly closed and the outer cover is tightened. 6.5 Industrial fluorosilicic acid should be transported in a dedicated vehicle and the tightness of the lid should be checked frequently. 6.6 Industrial fluorosilicic acid should be stored in a low-temperature, ventilated and dry warehouse. The warehouse temperature should not exceed 30°C. It is strictly forbidden to store it together with alkalis and other easily corrosive items.
7 Safety requirements
Industrial fluorosilicic acid is a strong acid that is toxic and corrosive. Protective clothing, gloves and protective glasses must be worn during storage and use. 5301 Method Summary
HG/T 2832--1997
After the sample is precipitated with saturated potassium nitrate to separate fluorosilicic acid, copper reacts with copper reagent to form a brown complex at pH = 9. It is extracted with ethyl acetate to improve the sensitivity of the method, and its content is determined by spectrophotometry. 5.5.2 Reagents and materials
5.5.2.1 Ammonia water;
5.5.2.2 Ethyl acetate;
Nitric acid solution: 1+1;
Ethylenediaminetetraacetic acid disodium solution: 50g/L; Saturated potassium nitrate solution;
Citric acid solution: 100g/L;
Sodium diethylaminodithiocarbamate (copper reagent) solution: 1.g/L; Copper standard solution: 1 ml solution contains 5μgCu; 5.5.2.8
Use a pipette to take 5ml of the copper standard solution prepared according to GB/T602, place it in a 100ml volumetric flask, dilute it to the mark with water, and shake it. This solution is prepared before use.
5.5.2.9 Phenolyl indicator solution: 10g/L.
5.5.3 Instruments and equipment
5.5.3.1 Spectrophotometer: with 3cm absorption cell; 5.5.3.2 Separating funnel: capacity 125mL. 5.5.4 Analysis steps
5.5.4.1 Drawing of working curve
Use a pipette to take 0mL, 1.00mL, 2.00mL, 3.00mL, 4.00mL, and 5.00mL of copper standard solution and place them in the separating funnel respectively, add 40mL of water, 5mL of disodium ethylenediaminetetraacetic acid solution, 10mL of citric acid solution and 1 drop of phenolic acid indicator solution, adjust to red with ammonia water, add 5mL of copper reagent, shake, let stand for 5min, add 10mL of ethyl acetate, and shake for 1min. After separation, put the lower aqueous phase into another separating funnel, add 5mL of copper reagent, shake, and then add 5mL of ethyl acetate for the second extraction, and discard the aqueous phase. Use filter paper to absorb the water attached to the necks of the two separating funnels, combine the organic phases, and put them into a 25mL colorimetric tube. Wash the separating funnel with ethyl acetate, add the washing liquid to the colorimetric tube, and dilute it to the scale with ethyl acetate and shake it well. Use a 3cm absorption cell and ethyl acetate as a reference at a wavelength of 430nm to measure the absorbance of the solution.
Use the mass of copper as the horizontal axis and the corresponding absorbance as the vertical axis to draw a working curve. 5.5.4.2 Determination
Use a pipette to transfer 50ml of test solution A (5.4.4.1) and place it in a separating funnel. Take another separating funnel and add 40ml of water for a blank test. The following operations are based on 5.5.4.1, starting from "adding 5mL of disodium ethylenediaminetetraacetic acid solution" to "measuring the absorbance of the solution".
Subtract the absorbance of the blank test solution from the measured absorbance of the test solution, and find the corresponding copper amount from the standard curve. 5.5.5 Expression of analysis results
The copper (Cu) content X expressed as mass percentage is calculated according to formula (3): X = mX10 6
m×100
2 ×mi × 10-4
The amount of copper in the test solution obtained from the working curve, ug; where: m-
-mass of the sample, g.
5.5.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.00005%. . (3)
5.6 Determination of heavy metal content
5.6.1 Summary of method
HG/T2832—1997
Under weak acidic conditions, the heavy metal ions in the sample react with hydrogen sulfide to produce brown-black color, which is compared with the standard. 5.6.2 Reagents and materials
5.6.2.1 Ammonia solution: 1+3;
5.6.2.2 Hydrochloric acid solution: c(HCI) about 0.1 mol/L, 5.6.2.3 Saturated hydrogen sulfide water;
5.6.2.4 Lead standard solution: 1 mL of solution contains 0.1 mg Pb. 5.6.3 Analysis steps
Use a pipette to transfer 10 mL of test solution A (5.4.4.1) into a 50 mL colorimetric tube, and adjust the pH to 3-4 with ammonia or hydrochloric acid solution (pH test paper test). Add 10 mL of saturated hydrogen sulfide water, dilute to the mark with water, shake the hook, and place in a dark place for 10 minutes. Its color should not be darker than the standard colorimetric solution.
The standard colorimetric solution is 1 mL of lead standard solution, which is treated in the same way as the test solution. 6 Marking, packaging, transportation, storage
6.1 The packaging of industrial fluosilicic acid should be firmly and clearly marked, including: manufacturer name, factory address, product name, trademark, grade, net weight, batch number or production date, this standard number and the "toxic" mark and "corrosive product" mark specified in GB190 and the "upward" mark specified in GB191.
6.2 Each batch of industrial fluosilicic acid shipped out of the factory should be accompanied by a quality certificate. The content includes: manufacturer name, factory address, product name, trademark, grade, net weight, batch number or production date, proof that the product quality meets this standard and this standard number. 6.3 When industrial fluosilicic acid is packaged in rubber or plastic barrels. It should be placed in a sturdy wooden box with a non-combustible material lining inside the box and reinforced with iron sheets or wire outside the box. The net weight of each barrel is 20kg or 40kg. It can also be transported by tank truck. 6.4 The inner cover of the industrial fluosilicic acid packaging barrel is tightly closed and the outer cover is tightened. 6.5 Industrial fluorosilicic acid should be transported in a dedicated vehicle and the tightness of the lid should be checked frequently. 6.6 Industrial fluorosilicic acid should be stored in a low-temperature, ventilated and dry warehouse. The warehouse temperature should not exceed 30°C. It is strictly forbidden to store it together with alkalis and other easily corrosive items.
7 Safety requirements
Industrial fluorosilicic acid is a strong acid that is toxic and corrosive. Protective clothing, gloves and protective glasses must be worn during storage and use. 5305.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.00005%. .(3)
5.6 Determination of heavy metal content
5.6.1 Method summary
HG/T2832—1997
Under weak acidic conditions, the heavy metal ions in the sample react with hydrogen sulfide to produce brown-black color, which is compared with the standard. 5.6.2 Reagents and materials
5.6.2.1 Ammonia solution: 1+3;
5.6.2.2 Hydrochloric acid solution: c(HCI) about 0.1 mol/L, 5.6.2.3 Saturated hydrogen sulfide water;
5.6.2.4 Lead standard solution: 1mL solution contains 0.1mgPb. 5.6.3 Analysis steps
Use a pipette to take 10mL of test solution A (5.4.4.1) and place it in a 50mL colorimetric tube. Use ammonia water or hydrochloric acid solution to adjust the pH to 3-4 (pH test paper test). Add 10mL of saturated hydrogen sulfide water, dilute to the scale with water, shake the hook, and place in a dark place for 10 minutes. Its color should not be darker than the standard colorimetric solution.
The standard colorimetric solution is 1mL of lead standard solution, which is treated in the same way as the test solution. 6 Marking, packaging, transportation, storage
6.1 The packaging of industrial fluorosilicic acid should be firmly and clearly marked, including: manufacturer name, address, product name, trademark, grade, net weight, batch number or production date, number of this standard, and the "toxic" mark and "corrosive product" mark specified in GB190 and the "upward" mark specified in GB191.
6.2 Each batch of industrial fluosilicic acid leaving the factory should be accompanied by a quality certificate. The content includes: manufacturer name, factory address, product name, trademark, grade, net weight, batch number or production date, proof that the product quality complies with this standard and the number of this standard. 6.3 When industrial fluosilicic acid is packaged in rubber or plastic barrels. It should be placed in a sturdy wooden box with a non-combustible material substrate inside and reinforced with iron sheets or wire outside. The net weight of each barrel is 20kg or 40kg. It can also be transported by tank truck. 6.4 The inner cover of the industrial fluosilicic acid packaging barrel should be tightly closed and the outer cover should be tightened. 6.5 During the transportation of industrial fluosilicic acid, a special vehicle should be used for special transportation, and the tightness of the cover should be checked frequently. 6.6 Industrial fluosilicic acid should be stored in a low-temperature, ventilated and dry warehouse. The warehouse temperature should not exceed 30℃. It is strictly forbidden to mix it with alkalis and other corrosive items.
7 Safety requirements
Industrial fluorosilicic acid is a strong acid that is toxic and corrosive. Protective clothing, gloves and protective glasses must be worn during storage and use. 5305.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.00005%. .(3)
5.6 Determination of heavy metal content
5.6.1 Method summary
HG/T2832—1997
Under weak acidic conditions, the heavy metal ions in the sample react with hydrogen sulfide to produce brown-black color, which is compared with the standard. 5.6.2 Reagents and materials
5.6.2.1 Ammonia solution: 1+3;
5.6.2.2 Hydrochloric acid solution: c(HCI) about 0.1 mol/L, 5.6.2.3 Saturated hydrogen sulfide water;
5.6.2.4 Lead standard solution: 1mL solution contains 0.1mgPb. 5.6.3 Analysis steps
Use a pipette to take 10mL of test solution A (5.4.4.1) and place it in a 50mL colorimetric tube. Use ammonia water or hydrochloric acid solution to adjust the pH to 3-4 (pH test paper test). Add 10mL of saturated hydrogen sulfide water, dilute to the scale with water, shake the hook, and place in a dark place for 10 minutes. Its color should not be darker than the standard colorimetric solution.
The standard colorimetric solution is 1mL of lead standard solution, which is treated in the same way as the test solution. 6 Marking, packaging, transportation, storage
6.1 The packaging of industrial fluorosilicic acid should be firmly and clearly marked, including: manufacturer name, address, product name, trademark, grade, net weight, batch number or production date, number of this standard, and the "toxic" mark and "corrosive product" mark specified in GB190 and the "upward" mark specified in GB191.
6.2 Each batch of industrial fluosilicic acid leaving the factory should be accompanied by a quality certificate. The content includes: manufacturer name, factory address, product name, trademark, grade, net weight, batch number or production date, proof that the product quality complies with this standard and the number of this standard. 6.3 When industrial fluosilicic acid is packaged in rubber or plastic barrels. It should be placed in a sturdy wooden box with a non-combustible material substrate inside and reinforced with iron sheets or wire outside. The net weight of each barrel is 20kg or 40kg. It can also be transported by tank truck. 6.4 The inner cover of the industrial fluosilicic acid packaging barrel should be tightly closed and the outer cover should be tightened. 6.5 During the transportation of industrial fluosilicic acid, a special vehicle should be used for special transportation, and the tightness of the cover should be checked frequently. 6.6 Industrial fluosilicic acid should be stored in a low-temperature, ventilated and dry warehouse. The warehouse temperature should not exceed 30℃. It is strictly forbidden to mix it with alkalis and other corrosive items.
7 Safety requirements
Industrial fluorosilicic acid is a strong acid that is toxic and corrosive. Protective clothing, gloves and protective glasses must be worn during storage and use. 530
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