Some standard content:
GB6549-1996
This standard adopts rOCT4568-83 (90) for the superior products of Class 1 and Class 1, I potassium chloride for industrial and agricultural use. The determination of potassium fluoride in the test method is equivalent to ISO2051:1976. The determination of water content is non-equivalent to ISO2053:1976. The determination of oxide chain is non-equivalent to NFT20-355;78, and the determination of water-insoluble matter is non-equivalent to NFT20-353.78 The differences between this standard and foreign standards are as follows: This standard adds special industrial potassium oxide, and industrial potassium oxide adds calcium and magnesium content indicators. The superior product also adds sodium oxide and water-insoluble matter content indicators. The particle size indicator of potassium fluoride for agricultural use is not determined. The water content indicator of industrial and agricultural potassium oxide is relatively high. This standard is proposed after the revision of GB654986 "Complex potassium and its test method". The previous version consisted of eight sub-standards, including potassium chloride and test methods, numbered GB6549 and GB6549.1~6549.7. This standard was revised and merged to form this standard. This standard has been revised on the basis of TOCT4568--83 (90) and the technical development of major potassium producing countries, combined with my country's resource characteristics, production process and use needs. The differences from the previous version are as follows: The main content of potassium chloride products has been changed to potassium chloride! Potassium chloride products are divided into three categories, namely special industrial potassium fluoride, industrial potassium fluoride and agricultural potassium fluoride. Agricultural potassium fluoride is mainly used to prepare compound fertilizers, etc. The potassium oxide content of qualified products is revised to be greater than or equal to 54%. The sulfate index and test method are removed, and the determination method of chlorine content is also removed! This standard replaces GB6549 and GB6549.1~6549.7-86 from the date of entry into force. This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China and is under the jurisdiction of the Chemical Industry Mining Design and Research Institute of the Ministry of Chemical Industry. The responsible drafting units of this standard are: Chemical Mining Design and Research Institute of the Ministry of Chemical Industry, Qinghai Potash Fertilizer Plant, and Qinghai Golmud Potassium Production. The main drafters of this standard are Li Donghao, Xu Xiulan, Xie Shengjia, Li Heyin, Le Tianshu, and Li Luwu. This standard was first issued on June 30, 1986. 1 Scope
National Standard of the People's Republic of China
Potassium chloride
Potassium chloride
GB6549—1996
Replaces GB 6549-—85
GB 6549.1~6549.7—86
This standard specifies the requirements, sampling, test methods, inspection regulations, marking, labeling, and packaging of potassium fluoride for industrial and agricultural use. This standard applies to industrial and agricultural potassium chloride products processed from carnallite and sylvite. 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision, and the parties using this standard should discuss the possibility of using the latest versions of the following standards. GB/T 601-88 Preparation of standard sugar solution for titration analysis (volume analysis) of chemical reagents GB/T1250-89 Methods for expressing and determining limit values GB/T6678--86 General rules for sampling of chemical products GB/T 6682-92 Specifications and test methods for water used in analytical laboratories GB/T9723-88 General rules for flame atomic absorption spectrometry of chemical reagents (neqISO6353-1.82GM29) 3 Product classification
Potassium chloride products are divided into three categories:
Class I is special industrial oxidation, suitable for electrolytic production of potassium oxyammonium, potassium oxyphosphine, etc. [Type is industrial potassium fluoride, suitable for the production of various potassium salts in the chemical industry. Type is agricultural potassium chloride, suitable for preparing compound fertilizers or directly used as fertilizers. 4 Requirements
4.1 Appearance, white or slightly red crystals. 4.2 Technical indicators of industrial and agricultural potassium chloride should meet the requirements of Table 1. Table 1 Technical requirements
Potassium chloride (K, O) total
Water (H, O)
State Bureau of Technical Supervision 1996-12-02 approved superior product
First-class product
Qualified product
Superior product
Qualified product
1997-05-01 actual
Calcium (Ca+Mg) total
Calcium (Ca>) content
Mg content
Sodium oxide (NaCl) content
Water and solid matter content
Note: Except for water, the content of each component is calculated on a dry basis 5 Sample
GB6549—1996
Table 1 (end)
Superior product
5 .1 Products of the same quality sent to the same user at the same time are considered a batch. 5.2 Determine the number of sample units in accordance with the provisions of 6.6 in GB/T6678-86. Quality products
Qualified products
Superior products
Qualified products
5.3 The sampler is inserted obliquely from one corner of the bag mouth to % of the bag depth to take samples. The collected samples are mixed evenly. The total amount should not be less than 2k. Use the quartering method to reduce it to about 1kg. Divide equal amounts into two clean, dry ground-mouth bottles or counting bottles, seal and indicate the manufacturer's name, product name, product category or use, product grade, batch number, sampling date and name of the sampler. One bottle is for inspection; the other bottle is kept for two months for re-inspection.
6 Test method
The water used in this standard shall comply with GB/T The specifications of trivalent water in 6682-92 and the listed reagents, unless otherwise specified, refer to analytically pure reagents.
The standard liquid required in the test shall be prepared in accordance with the provisions of GB/T601-88. 6.1 Determination of potassium oxide content
This method is equivalent to SO2051.1976% industrial potassium chloride - Determination of potassium content - Tetraphenylboron gravimetric method", 6.1.1 Method summary
After the sample is dissolved in water, formaldehyde solution is added to convert the existing ammonium ions into hexamethylenetetramine: ethylenediaminetetraacetic acid disodium (EDTA) is added to eliminate other cations that interfere with the analysis results. In a weakly alkaline medium, potassium is precipitated with sodium tetraphenylborate, the precipitate is dried and weighed. 6.1.2 Reagents and solutions
6.1.2.1 Sodium hydroxide solution: 200g/L, 6.1.2.2 Disodium ethylenediaminetetraacetic acid (EDTA) solution: 40 g/L. 6.1.2.3 Sodium tetraphenylborate CNaB(CH)J Alkaline dissolution: Dissolve 32.5g sodium tetraphenylborate in 480mL water, add 2mL sodium hydroxide solution (400g/L) and 20mL magnesium oxide solution (100g/L), stir for 15min, filter with medium-speed filter paper, the reagent can be used for about one week. If there is any confusion, filter before use.
6.1.2.4 Monoaldehyde solution 36% (v/)). Filter before use. 6.1.2.5 Washing liquid: Saturated potassium tetraphenylborate solution at room temperature. Add excess sodium tetraphenylborate solution to 100mL of liquid containing about 0.1g potassium fluoride for precipitation. The generated potassium tetraphenylborate precipitate is filtered with a No. 4 glass crucible filter and washed with distilled water until it is free of oxygen ions. Then transfer the precipitate to 5L of diluted water, suspend it, stir for 1h, and filter out the required amount when using. 6.1.2.6 Phenolphthalein indicator solution: Dissolve 0.5 g phenolic acid in 100 mL 95% ethanol. 6.1.3 Apparatus
GB 6549-1996
Briain filter: No. 4 filter, filter plate pore size 7~16 μm.6.1.4 Analysis steps
6.1.4.1 Preparation of test solution
Weigh about 5 g of sample 1, accurate to 0.001 g, place in a 400 mL beaker, add 150 mL water, heat under constant stirring, boil slightly for 5 min, remove and cool to 20°C, transfer to a 500 mL volumetric flask, dilute with water to the mark, and shake to the hook. This is solution A. Dry filter solution A and discard the first small amount of filtrate. Transfer 25.0 mL of the solution to a 250 mL volumetric flask, dilute with water to the mark, and shake to the hook. This is solution B.
6.1.4.2 Determination
Pipette 50.0 mL of solution B into a 250 mL beaker, add 10 mL of EDTA solution (6.1.2.2) and 2-3 drops of phenolic acid indicator solution (6.1.2.6), and add sodium hydroxide solution (6.1.2.1) drop by drop while stirring until red appears. Add 5 mL of formaldehyde solution (6.1.2.4). If the red color disappears at this time, add more sodium hydroxide solution (6.1.2.1) until it turns red. Cover the surface with blood and heat in a boiling water bath for 15 minutes. The solution should remain red at this time.
Remove the beaker, cool it slightly, and add 10 mL of sodium tetraphenylborate solution (6.1.2.3) drop by drop while stirring. Continue stirring for 1 minute. Cool it quickly in running water to below 20°C.Leave it for 10 min. Filter with a glass crucible filter that has been dried to a constant weight at 120 ± 2°C. Filter the upper clear liquid first, then transfer the precipitate to the filter with the washing liquid (6.1.2.5), and continue to wash the precipitate with the washing liquid (6.1.2.5) for about 12 times, using about 5 mL each time.
Filter and precipitate are dried in an oven at 120±2°C for 90 min. Take out the filter, put it into a desiccator and cool it to room temperature. Weigh it to an accuracy of 0.0001 g.
6.1.5 Expression of analytical results
6.1.5.1 The amount of potassium oxide (K2O) (X2O) expressed as mass percentage is calculated according to formula (1): X = 0.1314 × m × 100 ×
25 × 50
100 —1
mass of potassium tetraphenylborate after drying, which is
where: m - the mass of the sample, B1
x - the mass percentage of water in the sample, %, 0.131 6.1.5.2 The content of potassium fluoride (KCl) expressed as mass percentage (X,) is calculated according to formula (2): 0.208 1 × m × 100 ×
Where: m.ma-
Same as 6.1.5.1 #
0.208 1 -- The coefficient for converting the mass of potassium tetraphenylboron to the mass of potassium oxide. 6.1.6 Allowable difference
The arithmetic mean of the parallel analysis results is taken as the final analysis result. The absolute difference of the parallel analysis results for potassium fluoride should not be greater than 0.38%.
6.2 Determination of moisture
This method is not equivalent to ISO 2053:1976 Industrial potassium fluoride - Determination of moisture content - Gravimetric method.
6.2.1 Method Summary
Instructions:
1) Weigh 10g of sample from IS02051.
2] Add 10 mL of 30% (m/m) formaldehyde to the sample. GB 6549—1996
The sample is dried in an oven at 105±2°C. The removed mass is the water content. 6.2.2 Apparatus
6.2.2.1 Weighing bottle: with a glass stopper, flat, about 60mm in diameter and 30mm in height. 6.2.2.2 Electric oven, adjustable at 105±2°C. 6.2.2.3 Desiccator: Fill with appropriate desiccant, such as color-changing silica gel, phosphorus pentoxide, etc. 6.2.3 Analysis steps
Weigh the sample according to Table 2, accurate to 0.001g+ and place it in a weighing bottle that has been dried to a certain weight at 105±2℃ in advance. Gently shake the weighing bottle, spread the sample evenly in the weighing bottle, open the weighing bottle cap, and put it in an oven at 105±2℃ to dry for 2h. Take out the weighing bottle, cover it, put it in a desiccator to cool to room temperature, and weigh it. Repeat the operation until the constant weight is reached (the difference between the two weighings is not greater than 0.003g). Table 2 Sample weight
Water·%
6.2.4 Expression of analysis results
The water content (H, O) (z) expressed as mass percentage is calculated according to formula (3); ±= m= n± × 100
Where: m is the mass of the weighing bottle and sample before drying, m, z is the mass of the weighing bottle and sample after drying, and m is the mass of the sample·g.
Weigh the sample amount + 8
6.2.5 Allowable error
Take the arithmetic mean of the parallel analysis results as the final analysis result. When the content is less than or equal to 4.00%, the absolute difference should not be greater than 0.20%; when the content is greater than 4.00%, the absolute difference should not be greater than 0.30%. 6.3 Determination of calcium and magnesium content
6.3.1 Flame atomic absorption spectrometry - arbitration method 6.3.1.1 Method summary
The sample is dissolved in water, and chlorinated chromium is added to eliminate the interference of coexisting ions. In a dissolving acid medium, use an air-acetylene flame to measure the absorbance at wavelengths of 422.7nm and 285.2nm on the flame atomic absorption spectrometer, and use the working curve method to calculate the content of calcium and magnesium. 6.3.1.2 Reagents and liquids
6.3.1.2.1 Hydrochloric acid L: 1.19g/cm solution: 1+1. 6.3.1.2.2 Potassium chloride solution, 10mg/mL, weigh 10g potassium oxide in a 250mL beaker, dissolve it with water, transfer it to a 1000mL volumetric flask, dilute it to the mark with water, and mix well. 6.3.1.2.3 Copper chloride solution, 100/L. 6.3.1.2.4 Calcium standard solution: 1.00mg/mL, weigh 2.4972g calcium carbonate (high purity reagent) that has been dried at 105~110℃ for 1h and cooled to room temperature in a desiccator, place it in a 300mL beaker, moisten it with a small amount of water, add 20mL of water, and add hydrochloric acid solution (6.3.1.2.1) drop by drop until it is completely dissolved, with an excess of 10mL. Heat to boil, drive off all carbon dioxide, remove and cool to room temperature, transfer to a 1000tL volumetric flask, dilute to scale with water, and shake well. This solution contains 1.00 mg calcium in 1 mL. 6.3.1.2.5 Calcium standard solution: 100μg/mL, transfer 100.0mL calcium standard solution (6.3.1.2.4), measure in a 1000m positive volumetric flask, dilute to scale with water, and shake well. This solution contains 100 mg calcium in 1mL. 6.3.1.2.6 Calcium standard solution: 1.00mg/mL, weigh 1.6583g of oxidized bond (high purity reagent) that was previously burned at 900C for 1h and placed in a dryer to cool to room temperature, place in a 250mL beaker, moisten with a small amount of water, add 20mL water and 10mL hydrochloric acid solution GB 6549-1996
(6.3.1.2.1), and heat slightly until completely dissolved. Cool to room temperature, transfer to a 1000mL volumetric flask, dilute to scale with water, and shake well. This solution contains 1.00 mg magnesium in 1 mL.
6.3.1.2.7 Magnesium standard solution: 50μg/ml, transfer 50.0mL magnesium standard solution (6.3.1.2.6) to a 1000ml volumetric flask, dilute to scale with water, and shake well. This solution contains 50g magnesium in 1mL. 6.3.1.3 Apparatus
Flame atomic absorption spectrometer: It should comply with the provisions of GB/T9723-88. 6.3.1.4 Analysis steps
6.3.1.4.1 Preparation of test solution
Weigh the sample according to Table 3, accurately to 0.001g, place it in a 250mL beaker, add 100mL water, heat under constant stirring, and boil slightly for .5tmin, remove and cool to room temperature, transfer to a 250mL volumetric flask, dilute to scale with water, shake well and dry filter. At the same time, prepare a blank test solution.
6.3.1.4.2 Determination of calcium content
Put the test solution (6.3.1.4.1) according to Table 3 into a 100mL volumetric flask, add 10mL lanthanum chloride solution (6.3.1.2.3) and 4mL hydrochloric acid solution (6.3.1.2.1), dilute to scale with water, and shake well. On the atomic absorption spectrometer, use air-acetylene flame, adjust to zero with water at a wavelength of 422.71nm, and measure the absorbance of the test solution and the blank test solution. Subtract the absorbance of the blank test solution from the absorbance of the test solution, and find out the corresponding calcium concentration from the working curve. 6.3.1.4.3 Determination of content
According to Table 3, transfer the test solution (6.3.1.4.1) into a 100mL container bottle, add 10mL of chlorinated sodium solution (6.3.1.2:3) and 4mL of hydrochloric acid solution (6.3.1.2.1), dilute with water to the scale, and shake well. On the atomic absorption spectrometer, use air-acetylene flame, adjust to zero with water at a wavelength of 285.2nm, and measure the absorbance of the test solution and the blank test solution. Subtract the absorbance of the blank test solution from the absorbance of the test solution, and find out the corresponding magnesium concentration from the working curve. Table 3 Sample weight and volume of test solution absorbed Calcium or magnesium content
20. 4~1. 0
6.3.1.4.4 Drawing of working curve
Weighing value
Absorbed volume + ml
Pipette 0.0.1.0, 2.0, 4.0, 6.0, 8.0mL of calcium standard solution (6.3.1.2.5) and place them in 100mL volumetric flasks respectively. Then take 0.0, 1.0, 2.0, 4.0, 6.0, 8.0 mL of magnesium standard solution (6.3.1.2.7) and inject into the above 100 mL volumetric flask from small to large, add 10 mL of potassium chloride solution (6.3.1.2.2), 10 mL of steel fluoride solution (6.3.1.2.3) and 4 mL of hydrochloric acid solution (6.3.1.2.1), dilute with water to the scale, and spread with a spoon. The calcium concentration of this standard series is 0.0, 1.0, 2.0, 4.0, 6.0, 8.0g/mL, magnesium concentration is 0.0.0.5, 1.0.2.0.3.0, 4.0*g/mL. After measuring the absorbance under the same conditions as the test bath solution and subtracting the absorbance of the reagent blank solution, draw a working curve with calcium or magnesium concentration as the horizontal axis and the corresponding absorbance as the vertical axis. 6.3.1.5 Expression of analysis results
6.3.1.5.1 The calcium (Ca) content (X,) expressed as mass percentage is calculated according to formula (4): X, = ±× 100.× 10-6
×100×100=
m XV/250
Wherein, p is the calcium concentration in the tested solution obtained from the working curve, g/mL; m is the mass of the test sample, g
V is the volume of the test solution absorbed, mL,
GB 6549—1996
is the mass percentage of water in the test sample, %. 6.3.1.5.2 The magnesium (Mg) content (X,) expressed as mass percentage shall be calculated according to formula (5): X, = p × 100 × 10-
×100×100-
m XV/250
Wherein: p—the magnesium concentration in the tested solution obtained from the working curve, /mL;
-the mass of the sample.1
V——the volume of the absorbed test solution, mL;
-the mass percentage of water in the sample, %. 6.3.1.6 Allowable difference
The arithmetic mean of the parallel analysis results shall be taken as the final analysis result. The absolute difference of the parallel analysis results shall not be greater than the allowable difference listed in Table 4.
Table 4 Allowable difference
Calcium (Ca) or magnesium (Mg) content
0.20~1.00
6.3.2 EDTA titration method
6.3.2.1 Summary of the method
Allowable amount
After the sample is dissolved in water, add calcium carboxylic acid indicator under the condition of pH>12, and titrate the calcium with EDTA standard titration solution. When pH=10, add chrome black T indicator solution, and titrate the total amount of calcium and magnesium with EDTA standard titration solution, and calculate the magnesium content by difference subtraction. 6.3.2.2 Reagents and solutions
6.3.2.2.1 Water [p+0.89g/cm3] Solution: 1+1.6.3.2.2.2 Sodium hydroxide solution: 100 g/L. 6.3.2.2.3 Hydrogen peroxide solution: 3% (v/t). 6.3.2.2.4 Triethanolamine solution: 1 + 2. 6.3.2.2.5 Ammonia-ammonium fluoride buffer solution (pH = 10): weigh 67.5 g ammonium chloride and dissolve it in water, add 570 mL ammonia, dilute with water to 1000 mL, and mix well.
6.3.2.2.6 Disodium ethylenediaminetetraacetic acid (EDTA) standard titration solution: c(EDTA) = 0.02 mol/L, preparation and calibration shall be carried out in accordance with GB/T601.
6.3.2.2.7 Calcium carboxylate indicator [2-hydroxy-1-(2-carboxyl-4-sulfonic acid-1-indole azo)-3-carboxylic acid]: Weigh 0.2 g of calcium carboxylate indicator and 10 g of sodium chloride dried at 110°C, grind them in a mortar, mix them evenly, put them in a brown ground-mouth bottle, and place them in a desiccator for later use. 6.3.2.2.8 Chrome black T indicator solution: Weigh 0.5 g of Chrome black T and dissolve it in 100 mL of triethanolamine solution (6.3.2.2.4). 6.3.2.3 Analysis steps
6.3.2.3.1 Preparation of test solution
Weigh the sample according to Table 5 to an accuracy of 0.001 g, place it in a 400 mL beaker, add 150 mL of hot water, stir in 4 to 5 drops of hydrogen peroxide solution (6.3.2.2.3), heat to a slight boil until there are no small bubbles (about 5 min), remove and cool to room temperature, transfer to a 200 mL volumetric flask, dilute to the mark with water, shake well and dry filter. 6.3.2.3.2 Determination of calcium content
According to Table 5, transfer the test solution (6.3.2.3.1) into a 250 mL beaker, dilute it to about 100 mL with water, add 5 mL of triethanolamine solution (6.3.2.2.4), adjust the pH to above 12 with sodium hydroxide solution (6.3.2.2.2), add a small amount of calcium hydroxide indicator (6.3.2.2.7), stir well, and titrate with EDTA standard titration solution (6.3.2.2.6) until the solution changes from wine red to pure blue. 6.3.2.3.3 Determination of content
GB 65491996
According to Table 5, transfer the test solution (6.3.2.3.1) into a 250mL beaker, dilute with water to about 100mL, add 5mL triethanolamine solution (6.3.2.2.4), 5mL ammonia-oxidation recovery buffer solution (6.3.2.2.5) and two drops of chrome black T indicator solution (6.3.2.2.8), and stir well. Titrate with EDTA standard titration solution (6.3.2.2.6) until the solution changes from wine red to pure blue. 6.3.2.3.4 Blank test
The determination of calcium and magnesium content shall be carried out with the blank test at the same time as the sample determination. Table 5 Sample weight and volume of test solution taken Calcium or magnesium content, %
0. 1~ 0. 5
>0. 5~1. 0
6.3.2.4 Expression of analysis resultsWww.bzxZ.net
Sample weight·
6.3.2.4.1 The calcium (Ca) content (X,) expressed as mass percentage shall be calculated according to formula (6): X, ×(V:X0 040 08 × 00 x
m ×V/200
-actual concentration of EDTA standard titration solution, mol/L; where c
V,—volume of EDTA standard titration solution for calcium titration, mL100
100 — r
V,—-Volume of blank test solution for calcium titration with EDTA standard titration solution, mLV
Volume of absorbed test solution, mL
m—Mass of sample, g;
Yuan—Mass percentage of water in the sample, %, Adsorption volume, mL
0.04008—Mass of calcium expressed in grams equivalent to 1.00mLEDTA standard titration solution c(EDTA)=1.000mol/L. 6.3.2.4.2 Calculate the magnesium (Mg) content (X.) expressed in mass percentage according to formula (7). X, 5(V4-V)02 ×0. 024 30 × 100 ×100
mXV/200
Where: c—EDTA Actual concentration of standard titration solution, mol/L; V, — Volume of EDTA standard titration solution used to titrate calcium and magnesium, mLV, — Volume of blank test solution used to titrate calcium and magnesium by EDTA standard titration, mL; V, — Volume of blank test solution used to titrate calcium by EDTA standard titration solution, mLV-- Volume of absorbed test solution, mL;
— Mass of sample? 8 +
Mass percentage of water in the sample, %;
100 - 2
0.02430-- Mass of magnesium expressed in grams equivalent to 1.00 mL EDTA standard titration solution Lc(EDTA) = 1.000 mol/L>. 6. 3. 2. 5 Allowable difference
The arithmetic mean of the parallel analysis results shall be taken as the final analysis result. The absolute difference of the parallel analysis results shall not be greater than the allowable difference listed in Table 6.
Calcium (Ca) or magnesium (Mg) content
0. 20 ~~ 1. 00
6.4 Determination of sodium chloride content
GB 6549-1996
Table 6 Allowable difference
Allowable difference
This method is not equivalent to NFT20-355:78 Industrial potassium chloride - Determination of sodium content - Flame emission spectrophotometry". 6.4.1 Summary of the method
After the sample is dissolved in water, the sodium atoms are excited by flame, and the intensity of the 589nm spectral line generated is compared with the intensity emitted by the standard solution to calculate the content of sodium oxide.
6:4.2 Reagents and solutions
6.4.2.1 Potassium chloride solution, about 90 mg/mL, weigh 90 g potassium fluoride, dissolve in water, transfer to a 1000 mL volumetric flask, dilute to scale with water, and spread evenly.
6. 4.2,2 Sodium standard solution: 1. 0 mg/mL,Weigh 2.5421 g of sodium chloride (standard reagent) dried in advance at 100°C, dissolve it in water, transfer it to a 1000mL volumetric flask, dilute it to the mark with water, shake it well, and 1mL of this solution contains 1mg of sodium. 6.4.3 Instruments General laboratory instruments and flame photometer. 6.4.4 Analysis steps 6.4.4.1 Preparation of test solution Weigh 1g of sample to the nearest 0.0001 liter, measure it in a 250mL beaker, add 50mL of water, heat it under constant stirring, boil it slightly for 5min, cool it to room temperature, transfer it to a 500mL volumetric flask, dilute it to the mark with water, and stir. 6.4.4.2 Photometric measurement 6.4.4.2.1 Preliminary measurement Dry filter the test solution (6.4.4.1) and discard the initial small amount of filtrate. Transfer 50 mL of the filtrate into a 50 mL beaker and measure the radiation intensity of the sodium spectrum line according to the flame photometer regulations. Find the approximate sodium content in the test solution from the working curve. 6.4.4.2.2 Drawing of working curve (for preliminary measurement) Take 0.0, 5.0, 10.0, 15.0, 20.0, 25.0 mL of sodium standard solution (6.4.2.2) and inject them into 6 500 mL volumetric flasks respectively. Add 10.0 mL of potassium chloride solution (6.4.2.1) to each flask. Dilute to the mark with water and shake well. This series contains 0.0, 5.0, 10.0, 15.0, 20.0, 25.0 mg of sodium respectively. Take 50 m2L of sodium standard solution into a 50 mL beaker and measure the radiation intensity of the sodium spectrum line according to the prescribed operation of the flame photometer. Use the sodium concentration as the horizontal axis and the corresponding radioactivity as the vertical axis to draw the working curve. 6.4.4.2. 3 Accurate measurement insertion method Based on the preliminary measurement of the sodium content in the test solution, prepare two sodium standard solutions with similar concentrations so that the sodium content in the test solution is exactly in the middle, and then measure the radiation intensity of the sodium spectrum line according to the specified operation of the flame photometer. The analysis results should use the insertion method to calculate the sodium content. 6. 4.5 Expression of analysis results
6.4.5..1 The mass of sodium m. (mg) is calculated according to formula (8): E. - E
m) Ee-E,
mo = mi +(mz
-the sodium content in the low concentration standard solution, mgi In the formula,—
-the sodium content in the high concentration standard solution, mg1m2
E,—the measured value of the low concentration standard solution:-(8)
E: the measured value of the high concentration standard solution!
E. The measured value of the test solution.
GB 6549-1996
6.4.5.2 The sodium chloride (NaCl) content (X,) expressed as mass percentage is calculated according to formula (9): X, = m.×2.542 1×10 ×100 ×100
In the formula, m—
same as 6.4.5.11
mass percentage of water in the sample, %
m—mass of the sample g
2.5421——coefficient for converting the mass of sodium to the mass of sodium chloride. 6.4.6 Allowable difference
The arithmetic mean of the parallel analysis results is taken as the final analysis result. When the content is less than or equal to 2.00%, the absolute difference should not be greater than 0.10%; when the content is greater than 2.00%, the absolute difference should not be greater than 0.20%. 6. 5 Determination of water-insoluble matter content
This method is not equivalent to NFT20-353;78 Industrial potassium oxide - Determination of water-insoluble matter". 6.5.1 Summary of the method
After the sample is dissolved in water, the insoluble residue is filtered, dried and weighed to obtain the water-insoluble matter. 6.5.2 Reagents and solutions
6. 5. 2. 1 Silver nitrate solution, 10 g/L. 6.5.3 Instruments
6.5.3. 1 Electric oven, adjustable at 105±2℃. 6.5.3.2 Dryer: Install a suitable dryer, such as color-changing silica gel, phosphorus pentoxide, etc. 6.5.3.3 Glass volute filter: No. 4 or No. 3 filter. 6.5.4 Analysis steps
Weigh 10~~20g of sample, and make sure the sugar is 0.001g. Place it in a 400mL beaker, add 150mL of water, and boil it for 5min under constant stirring. Keep it in a boiling water bath for 30min. Remove the beaker, wait for the residue to sink, and then filter it with a glass filter (with medium-speed filter paper of the same diameter as the filter plate) that has been dried to constant temperature at 105±2℃. Before filtering, soak the filter with hot water to make the filter paper stick to the filter plate. Wash the residue with hot water until there is no chloride ions, and check it with silver nitrate solution (6.5.2.1). Put the filter with the residue in an oven at 105±2℃, dry it for 1h for the first time and 30min for the second time, until the difference between the two weighings is no more than 0.0003g.
6.5.5 Expression of analysis results
The water-insoluble matter (X) expressed as a mass percentage is calculated according to formula (10): X. = m = \ × 100 ×:
100 —
Wherein m1-the mass of the crucible filter, filter paper and residue + 1m: -—the mass of the filter and filter paper, g,
m——the mass of the sample + palace!
The mass percentage of water in the sample, %.
6.5.6 Allowable difference
-(10)
The arithmetic mean of the parallel analysis results is taken as the final analysis result. When the content is less than or equal to 0.20%, the absolute difference should not be greater than 0.02%; when the content is greater than 0.20%, the absolute difference should not be greater than 0.03%. 7 Inspection rules
7.1 Each batch of products shall be inspected by the quality inspection department of the manufacturer in accordance with this standard. The manufacturer shall ensure that the products shipped out of the factory meet the requirements of this standard GB6549-1996
and be accompanied by a quality certificate, the contents of which include: product name, product category or use, grade and technical requirements, net weight, this standard number, manufacturer name and address.
7.2 The user has the right to conduct quality inspection on the received products according to this standard. The number of bags for weight inspection shall be carried out according to the number of sampling units determined by GB/678. If the products are unqualified, samples shall be taken from the two reserved packaging bags and re-inspected. If there are any objections, they shall be raised within 15 days of arrival and resolved through negotiation. If arbitration is required, the provisions on product quality arbitration in the Product Quality Law of the People's Republic of China shall be followed. 7.3 This standard adopts the "rounded value comparison method" specified in GB/1250 to determine whether the test results meet the requirements of this standard. 8 Marking, labeling, packaging
8.1 Potassium chloride products should be packed in plastic woven bags with a lining weight of 50±0.5kg and an average net weight of not less than 50kg. Woven bags (plastic woven cloth/film). # per bag
8.2 The packaging bag should be printed with the following signs: product name, trademark, product category or use, grade or technical requirements, net weight, this standard number, production name and factory address.
8.3 During storage and transportation, moisture and damage to the packaging bag should be prevented.3 Accurate measurement insertion method Based on the preliminary measurement of the sodium content in the test solution, prepare two sodium standard solutions with similar concentrations so that the sodium content in the test solution is exactly in the middle, and then measure the radiation intensity of the sodium spectrum line according to the specified operation of the flame photometer. The analysis results should use the insertion method to calculate the sodium content. 6.4.5 Expression of analysis results
6.4.5..1 The mass of sodium m. (mg) is calculated according to formula (8): E. - E
m) Ee-E,
mo = mi +(mz
-the sodium content in the low concentration standard solution, mgi where,—
-the sodium content in the high concentration standard solution, mg1m2
E,—the measured value of the low concentration standard solution: -(8)
E: the measured value of the high concentration standard solution!
E. The measured value of the test solution.
GB 6549-1996
6.4.5.2 The sodium chloride (NaCl) content (X,) expressed as mass percentage is calculated according to formula (9): X, = m.×2.542 1×10 ×100 ×100
In the formula, m—
same as 6.4.5.11
mass percentage of water in the sample, %
m—mass of the sample g
2.5421——coefficient for converting the mass of sodium into the mass of sodium chloride. 6.4.6 Allowable difference
The arithmetic mean of the parallel analysis results is taken as the final analysis result. When the content is less than or equal to 2.00%, the absolute difference should not be greater than 0.10%; when the content is greater than 2.00%, the absolute difference should not be greater than 0.20%. 6. 5 Determination of water-insoluble matter content
This method is not equivalent to NFT20-353;78 Industrial potassium oxide-determination of water-insoluble matter". 6.5.1 Method summary
After the sample is dissolved in water, the insoluble residue is filtered, dried and weighed to obtain the water-insoluble matter. 6.5.2 Reagents and solutions
6.5.2.1 Silver nitrate solution, 10 g/L. 6.5.3 Instrument
6.5.3. 1 Electric oven, adjustable at 105±2℃. 6.5.3.2 Dryer: Install a suitable dryer, such as color-changing silica gel, phosphorus pentoxide, etc. 6.5.3.3 Glass volute filter: No. 4 or No. 3 filter. 6.5.4 Analysis steps
Weigh 10~~20g of sample, and make sure the sugar is 0.001g. Place it in a 400mL beaker, add 150mL of water, and boil it for 5min under constant stirring. Keep it in a boiling water bath for 30min. Remove the beaker, wait for the residue to sink, and use a glass deionized filter (dried to constant temperature at 105±2℃) Place medium-speed filter paper with the same diameter as the filter plate in the filter and filter. Before filtering, soak the filter with hot water to make the filter paper close to the filter plate. Wash the residue with hot water until there is no chloride ions. Check with silver nitrate solution (6.5.2.1). Put the crucible filter with residue in an oven at 105±2℃, dry for 1 hour for the first time and 30 minutes for the second time, until the difference between the two weighings is no more than 0.0003g.
6.5.5 Expression of analysis results
The water-insoluble matter (X) expressed as mass percentage is calculated according to formula (10): X. =m=\× 100×:
100 —
Where m1-mass of crucible filter, filter paper and residue + 1m: -—mass of filter and filter paper, g,
m——mass of sample + 1m!
mass percentage of water in the sample, %.
6.5.6 Allowable difference
-(10)
The arithmetic mean of the parallel analysis results shall be taken as the final analysis result. When the content is less than or equal to 0.20%, the absolute difference shall not be greater than 0.02%; when the content is greater than 0.20%, the absolute difference shall not be greater than 0.03%. 7 Inspection rules
7.1 Each batch of products shall be inspected by the quality inspection department of the manufacturer in accordance with this standard. The manufacturer shall ensure that the products shipped meet the requirements of this standard GB6549-1996
and be accompanied by a quality certificate, the contents of which include; product name, product category or use, grade and technical requirements, net quantity, this standard number, manufacturer name and address.
7.2 The user has the right to conduct quality inspection on the received products according to this standard. The number of bags for weight inspection shall be carried out according to the number of sampling units determined by GB/678. If the products are unqualified, samples shall be taken from the packaging bags of the two reserves and re-inspected. If there are any objections, they shall be raised within 15 days of arrival and resolved through negotiation. If arbitration is required, the provisions on product quality arbitration in the Product Quality Law of the People's Republic of China shall be followed. 7.3 This standard adopts the "rounded value comparison method" specified in GB/1250 to determine whether the test results meet the requirements of this standard. 8 Marking, labeling, packaging
8.1 Potassium chloride products should be packed in plastic woven bags with a lining weight of 50±0.5kg and an average net weight of not less than 50kg. Woven bags (plastic woven cloth/film). # per bag
8.2 The packaging bag should be printed with the following signs: product name, trademark, product category or use, grade or technical requirements, net weight, this standard number, production name and factory address.
8.3 During storage and transportation, moisture and damage to the packaging bag should be prevented.3 Accurate measurement insertion method Based on the preliminary measurement of the sodium content in the test solution, prepare two sodium standard solutions with similar concentrations so that the sodium content in the test solution is exactly in the middle, and then measure the radiation intensity of the sodium spectrum line according to the specified operation of the flame photometer. The analysis results should use the insertion method to calculate the sodium content. 6.4.5 Expression of analysis results
6.4.5..1 The mass of sodium m. (mg) is calculated according to formula (8): E. - E
m) Ee-E,
mo = mi +(mz
-the sodium content in the low concentration standard solution, mgi where,—
-the sodium content in the high concentration standard solution, mg1m2
E,—the measured value of the low concentration standard solution: -(8)
E: the measured value of the high concentration standard solution!
E. The measured value of the test solution.
GB 6549-1996
6.4.5.2 The sodium chloride (NaCl) content (X,) expressed as mass percentage is calculated according to formula (9): X, = m.×2.542 1×10 ×100 ×100
In the formula, m—
same as 6.4.5.11
mass percentage of water in the sample, %
m—mass of the sample g
2.5421——coefficient for converting the mass of sodium into the mass of sodium chloride. 6.4.6 Allowable difference
The arithmetic mean of the parallel analysis results is taken as the final analysis result. When the content is less than or equal to 2.00%, the absolute difference should not be greater than 0.10%; when the content is greater than 2.00%, the absolute difference should not be greater than 0.20%. 6. 5 Determination of water-insoluble matter content
This method is not equivalent to NFT20-353;78 Industrial potassium oxide-determination of water-insoluble matter". 6.5.1 Method summary
After the sample is dissolved in water, the insoluble residue is filtered, dried and weighed to obtain the water-insoluble matter. 6.5.2 Reagents and solutions
6.5.2.1 Silver nitrate solution, 10 g/L. 6.5.3 Instrument
6.5.3. 1 Electric oven, adjustable at 105±2℃. 6.5.3.2 Dryer: Install a suitable dryer, such as color-changing silica gel, phosphorus pentoxide, etc. 6.5.3.3 Glass volute filter: No. 4 or No. 3 filter. 6.5.4 Analysis steps
Weigh 10~~20g of sample, and make sure the sugar is 0.001g. Place it in a 400mL beaker, add 150mL of water, and boil it for 5min under constant stirring. Keep it in a boiling water bath for 30min. Remove the beaker, wait for the residue to sink, and use a glass deionized filter (dried to constant temperature at 105±2℃) Place medium-speed filter paper with the same diameter as the filter plate in the filter and filter. Before filtering, soak the filter with hot water to make the filter paper close to the filter plate. Wash the residue with hot water until there is no chloride ions. Check with silver nitrate solution (6.5.2.1). Put the crucible filter with residue in an oven at 105±2℃, dry for 1 hour for the first time and 30 minutes for the second time, until the difference between the two weighings is no more than 0.0003g.
6.5.5 Expression of analysis results
The water-insoluble matter (X) expressed as mass percentage is calculated according to formula (10): X. =m=\× 100×:
100 —
Where m1-mass of crucible filter, filter paper and residue + 1m: -—mass of filter and filter paper, g,
m——mass of sample + 1m!
mass percentage of water in the sample, %.
6.5.6 Allowable difference
-(10)
The arithmetic mean of the parallel analysis results shall be taken as the final analysis result. When the content is less than or equal to 0.20%, the absolute difference shall not be greater than 0.02%; when the content is greater than 0.20%, the absolute difference shall not be greater than 0.03%. 7 Inspection rules
7.1 Each batch of products shall be inspected by the quality inspection department of the manufacturer in accordance with this standard. The manufacturer shall ensure that the products shipped meet the requirements of this standard GB6549-1996
and be accompanied by a quality certificate, the contents of which include; product name, product category or use, grade and technical requirements, net quantity, this standard number, manufacturer name and address.
7.2 The user has the right to conduct quality inspection on the received products according to this standard. The number of bags for weight inspection shall be carried out according to the number of sampling units determined by GB/678. If the products are unqualified, samples shall be taken from the packaging bags of the two reserves and re-inspected. If there are any objections, they shall be raised within 15 days of arrival and resolved through negotiation. If arbitration is required, the provisions on product quality arbitration in the Product Quality Law of the People's Republic of China shall be followed. 7.3 This standard adopts the "rounded value comparison method" specified in GB/1250 to determine whether the test results meet the requirements of this standard. 8 Marking, labeling, packaging
8.1 Potassium chloride products should be packed in plastic woven bags with a lining weight of 50±0.5kg and an average net weight of not less than 50kg. Woven bags (plastic woven cloth/film). # per bag
8.2 The packaging bag should be printed with the following signs: product name, trademark, product category or use, grade or technical requirements, net weight, this standard number, production name and factory address.
8.3 During storage and transportation, moisture and damage to the packaging bag should be prevented.6 Allowable difference
-(10)
The arithmetic mean of the parallel analysis results is taken as the final analysis result. When the content is less than or equal to 0.20%, the absolute difference should not be greater than 0.02%; when the content is greater than 0.20%, the absolute difference should not be greater than 0.03%. 7 Inspection rules
7.1 Each batch of products shall be inspected by the quality inspection department of the manufacturer in accordance with this standard. The manufacturer shall ensure that the products shipped meet the requirements of this standard GB6549-1996
and be accompanied by a quality certificate, the contents of which include; product name, product category or use, grade and technical requirements, net weight, this standard number, manufacturer name and address.
7.2 The user has the right to conduct quality inspection on the received products in accordance with this standard. The number of bags for weight inspection shall be carried out according to the number of sampling units determined by GB/678. If unqualified, samples shall be taken from the packaging bags of the two reserves and re-inspected. If there is any objection, it should be raised within 15 days of arrival and resolved through negotiation. If arbitration is required, it shall be carried out in accordance with the provisions of the "Product Quality Law of the People's Republic of China" on product quality arbitration. 7.3 This standard adopts the "rounded value comparison method" specified in GB/1250 to determine whether the inspection results meet the requirements of this standard. 8 Marking, labeling, packaging
8.1 Potassium chloride products should be packed in plastic woven bags with inner lining, with a net weight of 50±0.5kg and an average net weight of not less than 50kg. Woven bags (plastic woven cloth/film). # per bag
8.2 The packaging bag should be printed with the following marks: product name, trademark, product category or use, grade or technical requirements, net weight, this standard number, production name and factory address.
8.3 During storage and transportation, moisture and damage to the packaging bag should be prevented.6 Allowable difference
-(10)
The arithmetic mean of the parallel analysis results is taken as the final analysis result. When the content is less than or equal to 0.20%, the absolute difference should not be greater than 0.02%; when the content is greater than 0.20%, the absolute difference should not be greater than 0.03%. 7 Inspection rules
7.1 Each batch of products shall be inspected by the quality inspection department of the manufacturer in accordance with this standard. The manufacturer shall ensure that the products shipped meet the requirements of this standard GB6549-1996
and be accompanied by a quality certificate, the contents of which include; product name, product category or use, grade and technical requirements, net weight, this standard number, manufacturer name and address.
7.2 The user has the right to conduct quality inspection on the received products in accordance with this standard. The number of bags for weight inspection shall be carried out according to the number of sampling units determined by GB/678. If unqualified, samples shall be taken from the packaging bags of the two reserves and re-inspected. If there is any objection, it should be raised within 15 days of arrival and resolved through negotiation. If arbitration is required, it shall be carried out in accordance with the provisions of the "Product Quality Law of the People's Republic of China" on product quality arbitration. 7.3 This standard adopts the "rounded value comparison method" specified in GB/1250 to determine whether the inspection results meet the requirements of this standard. 8 Marking, labeling, packaging
8.1 Potassium chloride products should be packed in plastic woven bags with inner lining, with a net weight of 50±0.5kg and an average net weight of not less than 50kg. Woven bags (plastic woven cloth/film). # per bag
8.2 The packaging bag should be printed with the following marks: product name, trademark, product category or use, grade or technical requirements, net weight, this standard number, production name and factory address.
8.3 During storage and transportation, moisture and damage to the packaging bag should be prevented.
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