This standard specifies the chemical analysis methods for potassium feldspar loss on ignition, silicon dioxide, ferric oxide, titanium dioxide, aluminum oxide, calcium oxide, magnesium oxide, potassium oxide and sodium oxide. This standard is suitable for the analysis of the chemical composition of potassium feldspar for electrical porcelain. JB/T 5893.6-1991 Chemical analysis method of potassium feldspar raw material for electrical porcelain JB/T5893.6-1991 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T 5893.6-1991
Raw Materials for Electrical Porcelain
Published on October 24, 1991
Chemical Analysis Method of Potassium Feldspar
Implemented on October 1, 1992
Published by the Ministry of Machinery and Electronics Industry of the People's Republic of China
Mechanical Industry Standard of the People's Republic of China
Raw Materials for Electrical Porcelain
Chemical Analysis Method of Potassium Feldspar
1 Subject Content and Scope of Application
JB/T5893.61991
This standard specifies the chemical analysis methods for potassium feldspar loss on ignition, silicon dioxide, ferric oxide, titanium dioxide, aluminum oxide, calcium oxide, magnesium oxide, potassium oxide, and sodium oxide. This standard is applicable to the analysis of the chemical composition of potassium feldspar for electrical porcelain. 2 General provisions
2.1 The sensitivity of the analytical balance used is 0.0001g, and the balance base should be calibrated regularly. 2.2 When weighing the sample, the reading should be accurate to 0.0c01g. "Constant" means that the difference between two consecutive weighings is not greater than 0.0002g. 2.3 The instruments and measuring instruments used should be calibrated. 2.4 The sample for analysis should be dried in an oven at a temperature range of 105110℃ for more than 2h. Then put it in a dryer, cool it to room temperature, and weigh it.
2.5 The water used for analysis should be double distilled water or deionized water (resistivity greater than 1.0M2·cm); the reagents used should be analytically pure or superior pure; the reagents used to calibrate the concentration of the solution should be the reference reagent; blank tests should be performed on water and reagents. 2.6 The reagent concentration specified in the standard shall be expressed in the following way. 2.6.1 When the acid and ammonium hydroxide are directly indicated by name, they refer to reagents that meet the following percentage concentrations: Reagent name
Hydrofluoric acid bZxz.net
Ammonium hydroxide
Reagent concentration %:
Above 40
The concentration of diluted acid and ammonium hydroxide is expressed in the following form; for example, hydrochloric acid (5+95) refers to a solution prepared by adding 5 volumes of concentrated hydrochloric acid (36%2.6.2
~38%) to 95 volumes of water. 2.6.3 The concentration of a solution prepared by a solid reagent is expressed in mass/volume (m/V) percentage concentration (except when used as a standard solution). For example: 10% sodium chloride refers to a solution prepared by dissolving 10g of sodium fluoride in 100ml of water. When the solvent is not specifically specified, water is used as the solvent. 2.7 The reference solution for photometric measurement is specified as follows. 2.7.1 The "reagent blank solution" used in making the standard curve refers to the solution in the first volumetric flask that does not contain the element to be measured. 2.7.2 The "blank test" used in sample analysis refers to the solution without the sample obtained according to the sample determination and analysis steps. 2.8 The allowable difference refers to the absolute error of the values ​​of the same sample, which should be measured twice by the same person in the same laboratory at different times. 3
Preparation of sample
The extracted sample must be mixed evenly and should represent the average composition without foreign impurities. This sample is reduced and finally about 20g of sample is obtained. Grind it in a Marais mortar until it passes through a 75μm aperture sieve, and then put it into a weighing bottle for use. 4 Determination of loss on ignition (I.L)
Approved by the Ministry of Machinery and Electronics Industry on October 24, 1991 and implemented on October 1, 1992
4.1 Summary of the method
JB/T5893.6-1991
Place the sample in a temperature range of 950-1000℃ and burn it to constant weight. 4.2 Analysis steps
Weigh 1g of sample in a constant amount of platinum, put it in a high-temperature furnace, start heating from room temperature, and burn it in a temperature range of 950-1000℃ for 1h. Take it out, cool it slightly, place it in a desiccator and cool it to room temperature, and weigh it. Repeat the burning until constant weight. The percentage of loss on ignition is calculated according to formula (1):
m=ml×100%
In the formula; m-mass of sample before burning, g; m;-mass of sample after burning, g.
5 Determination of silicon dioxide
5.1 Summary of the method
After the sample is melted with anhydrous sodium carbonate at high temperature, it is leached with hydrochloric acid, evaporated and dehydrated, the salts are dissolved with hydrochloric acid, filtered and burned into silicon dioxide. Then it is treated with hydrofluoric acid to remove silicon in the form of silicon tetrafluoride. The mass difference before and after the hydrochloric acid treatment is the amount of silicon dioxide in the precipitate. The amount of silicon dioxide in the filtrate is determined by the silicon molybdenum blue photometry. The sum of the two is the amount of silicon dioxide in the sample. 5.2 Reagents
Silver nitrate solution (1%): weigh 0.5g silver nitrate and dissolve it in 50ml water, add 0.5ml nitric acid, mix well, and store in a 60ml brown dropper bottle: anhydrous sodium carbonate: high-grade pure;
hydrochloric acid: (1+1), (1+11), (5+95); nitric acid: (1+1);
ammonium sulfate solution (5%): store in a plastic bottle; ascorbic acid solution (2%): prepare when using; potassium oxide solution (2%): weigh 2g potassium fluoride (KF·2IJ,O) in a plastic cup, add Dissolve in 100ml water and store in a plastic bottle; Boric acid solution (2%);
Para-nitrophenol indicator (0.5%): weigh 0.5g para-nitrophenol and dissolve in 100ml 95% ethanol; Potassium hydroxide solution (20%): weigh 20g potassium hydroxide in a plastic cup, add 100ml water to dissolve, and store in a plastic bottle; 95% ethanol;
Silicon dioxide standard solution: weigh 0.1g high-purity quartz (99.99%) that has been calcined at 1000C for 1h in a platinum snail, add 1.5g anhydrous sodium carbonate, and mix well. Within 2 to 2.5h, gradually increase the temperature from room temperature to 980℃, maintain for 5min, and cool. Use hot water to soak the block in a 300ml plastic cup, add 150ml boiling water, stir to dissolve it, and the solution should be clear at this time, and cool. Transfer to a 1L volumetric flask, dilute to scale with water, mix well and immediately transfer to a plastic bottle for storage. This solution contains 0.1mg silicon dioxide per milliliter. 5.3 Instrument
Spectrophotometer.
5.4 Analysis steps
5.4.1 Blank test
Carry out a blank test with the sample, and the reagents used must be taken from the same reagent bottle. 5.4.2 Drawing of the standard curve of the silica blue photometry Accurately transfer 20ml of the silicon dioxide standard solution to a 100ml volumetric flask, dilute to scale with water, and shake well. This solution contains 20μg silicon dioxide per milliliter, and it is prepared when used.
Accurately pipette 0.00, 1.00, 2.00, 3.00, 4.00, and 5.00 ml of the prepared silica standard solution (20 μg/ml) into a group of 100 ml plastic cups, add 10 ml of hydrochloric acid (1+11) and 5 ml of potassium fluoride solution (2%), mix well, and place for 30 minutes. Add 5 ml of boric acid solution (2%), a drop of p-nitrophenol indicator (0.5%), and potassium hydroxide solution (20%) until the solution turns yellow, add 8 ml of saline (1+11), transfer to 100 ml volumetric flasks, add 8 ml of ethanol (95%) and 5 ml of ammonium molybdate solution (5%), and mix. Let stand for an appropriate time (25-30 minutes below 20°C; 20 minutes at 20-30°C; 10 minutes above 30°C). Dilute with water to about 90 ml, add 5 ml ascorbic acid solution (2%), dilute with water to the scale, and shake well. After 1 hour, use the reagent blank solution as a reference on a spectrophotometer, select 30 mm colorimetric blood, and measure the absorbance at a wavelength of 660 nm. Draw a standard curve based on the measured absorbance and the concentration of the series of solutions. 5.4.3 Determination
Weigh 0.5g sample, placed in platinum glass. Add 3g anhydrous sodium carbonate, mix well, add 1g anhydrous sodium carbonate to spread on the surface, cover with platinum cover, and leave a little gap. Move into a high-temperature furnace, heat from low temperature to 950-1000℃ and melt for 30min, take out and cool to room temperature. Add 1015ml boiling water to the platinum glass, gently stir the melt in the platinum crucible with a flat-headed glass rod, and let it evaporate into 150ml of porcelain evaporating blood with a handle. Wash the platinum crucible and platinum cover with hot water and hydrochloric acid (1 + 1), add 25ml hydrochloric acid, and quickly cover the watch glass. After the melt is completely decomposed and no bubbles are emitted, wash the surface with hot water. Move the porcelain evaporating dish with a handle to a water bath for evaporation, and crush the precipitated salts with a flat-headed glass rod at any time until there is no hydrochloric acid smell. Place the porcelain evaporating dish in an oven and bake it at a temperature range of 130-135℃ for 1h. Take out the porcelain evaporating dish, cool it slightly, add 10ml hydrochloric acid to the porcelain evaporating dish, stir it thoroughly, and let it stand for 5 minutes. Add 60-70ml boiling water, stir it thoroughly with a fan-shaped glass rod and crush the precipitate to dissolve the soluble salts. Filter it with slow quantitative filter paper, and collect the filtrate in a 250ml volumetric flask. Wash the precipitate with hot hydrochloric acid (5+95) 3 times, and then wash it with hot water until there is no chloride ion (check with 1% silver nitrate solution). Put the precipitate and the filter paper in a platinum crucible, and add 3 drops of sulfuric acid (1+1). After drying and carbonizing on an electric furnace, move it into a high-temperature furnace, first ash it at low temperature (500-600℃), and then burn it at a temperature range of 950-1000℃ for 1h, take it out, cool it slightly, place it in a desiccator, and weigh it after cooling it to room temperature. Repeat the burning until the constant weight is reached. Moisten the precipitate after burning in the platinum with a few drops of water, add 2-3 drops of sulfuric acid (1+1) and 5-7ml of hydrochloric acid, evaporate to dryness on a sand bath, repeat the process once, and continue heating until all the white smoke of sulfur trioxide is emitted. Place the platinum crucible in a high-temperature furnace and burn it in the range of 950-1000℃ for 15min. Take it out, place it in a dryer, cool it to room temperature, and weigh it. Repeat this operation until the constant weight is reached. Add 1g of anhydrous sodium carbonate to the platinum crucible treated with hydrofluoric acid, add a platinum cover and place it in a high-temperature furnace at 950-1000℃ to melt. When the sodium carbonate is fluid, clamp the platinum crucible with a crucible tongs with a platinum head and rotate it carefully to make the molten body flow along the inner wall of the crucible and spread to the place where the residue is. Cover the platinum cover again, place the platinum crucible in a high-temperature furnace at 950-1000℃, and melt it for 15min. Take it out and rotate it quickly to make the molten body evenly distributed on the inner wall of the platinum crucible and cool it. Wash the platinum crucible and cover with boiling water. After the melt is dissolved, acidify with hydrochloric acid, cool to room temperature, add to the silica filtrate, dilute with water to the scale, and mix well. For the determination of iron, aluminum, titanium, calcium, magnesium and silicon content in the filtrate. Accurately pipette 10ml of the above desiliconized filtrate into a 100ml plastic cup, add 5ml potassium fluoride solution (2%), mix well, and let stand for 30min. Add 5ml boric acid solution (2%) and a drop of p-nitrophenol indicator (0.5%), add potassium hydroxide solution (20%) until the solution turns yellow, add 8ml hydrochloric acid (1+11) and transfer to a 100ml volumetric flask. Add 8ml ethanol (95%) and 4ml ammonium aluminate solution (5%) and mix well. Let stand for an appropriate time (25~30min below 20℃; 20min at 20~30C; 10min above 30C). Dilute with water to nearly 90 ml, add 5 ml of ascorbic acid solution (2%), dilute with water to the scale, and mix. After 1 hour, use a blank test as a reference on a spectrophotometer, select a 30 mm cuvette, and measure the absorbance at a wavelength of 660 nm. Find the corresponding amount of silicon dioxide from the standard curve. The percentage of silicon dioxide is calculated according to formula (2): 250
(mm)+B×
10×100
SiO: (percentage)
Where: m,--mass of precipitate and platinum, g; m
m, mass of residue and platinum crucible after hydrofluoric acid treatment and calcination, g: m—mass of sample, g:
B—mass of silicon dioxide measured by silicon molybdenum blue photometry, g; 250 total volume of test solution, ml;
10—volume of test solution taken one by one, ml.
Note: When factories and mines conduct internal determination of silicon dioxide, other equivalent methods (whose allowable difference complies with this standard) may be used. In case of doubt, this method must be used for secondary analysis.
6 Determination of ferric oxide
6.1 Method 1
JB/T5893.6-1991
6.1.1 Method Summary
Iron (II) is reduced to iron (1) with hydroxylamine hydrochloride. In a weakly acidic solution, iron (I) forms an orange-red complex with o-phenanthroline, and its absorbance is measured at a wavelength of 510nm on a spectrophotometer. 6.1.2 Reagents
Hydrochloric acid (1+1);
Hydroxylamine hydrochloride solution (10%);
Phenomenaline solution (1%): Prepared with ethanol (1+1); Ammonium acetate solution (20%);
Ferric oxide standard solution A: Weigh 0.1g of ferric oxide (99.99%) previously calcined at 600C for 30min in a beaker, add a little water to moisten, add 20ml hydrochloric acid (1+1), heat and dissolve on an electric stove until the solution is clear, cool to room temperature, transfer to a 1L volumetric flask, dilute to scale with water, and mix well. This solution contains 0.1mg of ferric oxide per milliliter. Transfer this ferric oxide standard solution to a plastic bottle for storage. Ferric oxide standard solution B: Accurately transfer 50ml of ferric oxide standard solution A to a 500ml volumetric flask, dilute to scale with water, and mix well. This solution contains 10μg of ferric oxide per ml and is prepared when used. 6.1.3 Instrument only
Spectrophotometer.
6.1.4 Analysis steps
6.1.4.1 Blank test
Carry out a blank test together with the sample. The reagents used must be taken from the same reagent bottle. 6.1.4.2 Drawing of the standard curve of the o-phenanthroline photometric method Accurately transfer 0.00, 2.00, 4.00, 6.00, 8.00, and 10.00 ml of ferric oxide standard solution B and place them in a group of 100 ml volumetric flasks, add about 50 ml of water, add 5 ml of hydroxylamine hydrochloride solution (10%), 5 ml of o-phenanthroline solution (1%), and 10 ml of ammonium acetate solution (20%), dilute to the scale with water, and mix well. After 30 minutes, use 30mm colorimetric blood to measure the absorbance at 510nm on the spectrophotometer, with the reagent blank as reference. Draw a standard curve based on the measured absorbance and the concentration of the series of solutions. 6.1.4.3 Determination
Accurately transfer 20ml of the silicon-free filtrate into a 100ml volumetric flask, add about 50ml of water, add 5ml of hydroxylamine hydrochloride solution (10%), 5ml of o-phenanthroline solution (1%), and 10ml of ammonium acetate solution (20%), dilute with water to the scale, mix well, and let it stand for 30 minutes. Use a 30mm colorimetric dish to measure the absorbance at 510nm on the spectrophotometer, with the blank reagent as reference. Find the corresponding amount of ferric oxide from the standard curve. The percentage of ferric oxide is calculated according to formula (3): Fe.0, (percentage) = m×10~
×100%
The mass of ferric oxide, g, is obtained from the standard curve: Where: m.
m mass of sample, g;
20——volume of test solution, ml;
250——total volume of test solution, ml.
6.2 Method
6.2.1 Summary of method
The absorbance of iron in the desiliconized filtrate is measured at a wavelength of 248.3 nm using an air-acetylene flame on an atomic absorption spectrophotometer. 6.2.2 Reagents
Hydrochloric acid: (1+1), high purity;
Ferric oxide standard solution: same as Ferric oxide standard solution A in 6.1.2 (containing 0.1 mg of ferric oxide per liter); 4
JB/T5893.6-1991
Ferric oxide standard series solution; Accurately transfer 0, 2.00, 5.00, 10.00, 15.00, 20.00 ml of the above standard solution, respectively, into a set of 250 ml volumetric flasks containing blank test in advance, dilute to the mark with water, and mix. Transfer to 250 ml plastic bottles respectively. This standard series solution contains 0.0, 0.8, 2.0, 4.0, 6.0, 8.0 μg of ferric oxide per liter. 6.2.3 Instruments
Atomic absorption spectrophotometer
6.2.4 Analysis procedures
6.2.4.1 Blank test
A blank test should be carried out together with the sample. The reagents used should be taken from the same reagent bottle. 6.2.4.2 Determination
Adjust the atomic absorption spectrophotometer to the working state according to the operating procedures of the instrument used. Select appropriate instrument parameters (slit width, lamp current, burner height, flame state, gain amplification, logarithmic conversion, scale expansion, etc.), use an iron hollow cathode lamp, air-acetylene flame, and determine ferric oxide at a wavelength of 248.3nm as follows. Spray the zero solution of the standard series to zero the instrument; spray the sample solution and read the absorbance (D)
From the standard series solution: select a standard solution with a slightly smaller concentration than the sample solution for spraying, and read the absorbance (D,). Then select a standard solution with a slightly larger concentration than the sample solution for spraying, and read the absorbance (D,). The percentage of ferric oxide is calculated according to formula (4): [C, +(C2 - C,).
Fe,O, (percentage)
D, - D,
J×V×10-5
-×100%
Wherein: C, — concentration of standard solution slightly lower than that of the sample solution, ug/ml; C, — concentration of standard solution slightly higher than that of the sample solution, μg/ml; V — total volume of the sample solution, ml;
m — mass of the sample, g.
7 Determination of titanium dioxide
7.1 Summary of method
(4)
Accurately pipette the filtrate after silicon removal. In a strongly acidic medium, titanium forms a yellow complex with diantipyryl methane. Measure its absorbance at a wavelength of 385 or 430 nm on a spectrophotometer. Interference of trivalent iron can be eliminated by adding ascorbic acid. 7.2 Reagents
Potassium pyrosulfate: solid, high-grade pure;
Hydrochloric acid: (1+1);
Sulfuric acid: (1+1);
Ascorbic acid solution (2%): prepared when used; Diantipyrine methane solution (4%): prepared with hydrochloric acid (1+23); Standard storage solution of titanium dioxide: weigh 0.1g of titanium dioxide (spectrally pure) previously calcined at 950℃ for 1h in a platinum crucible; add about 3g of potassium pyrosulfate, melt it on an electric furnace first, then transfer it to a blowtorch and melt it until it becomes transparent. After cooling, use 20ml of hot sulfuric acid (1+1) to take the molten block and place it in a beaker pre-filled with 80ml of sulfuric acid (1+1), heat and dissolve it. After cooling, transfer it to a 1L volumetric flask, dilute it to the mark with water, and mix well. Stored in a plastic bottle, this solution contains 0.1 mg titanium dioxide per milliliter. Titanium dihydride standard solution: Accurately transfer 50 ml of titanium dioxide standard storage solution to a 500 ml volumetric flask, dilute to scale with water, mix well, and transfer to a plastic bottle. This solution contains 10 μg titanium dioxide per milliliter (if turbid, it should be discarded). 7.3 Instruments
Spectrophotometer.
7.4 Analysis steps
7.4.1 Blank test
JB/T5893.6-1991
Carry out a blank test with the sample, and the reagents used must be taken from the same reagent bottle. 7.4.2 Drawing of standard curve
Accurately pipette 0, 0.50, 1.00, 2.00, 4.00, 6.00, 8.00 ml of titanium difluoride standard solution (1 ml contains 10 g of titanium difluoride) into a set of 100 ml volumetric flasks, add 2 ml of ascorbic acid solution (2%), mix well, let stand for 3-5 min, add 10 ml of diantipyrine methane solution (4%), 20 ml of hydrochloric acid (1+1), dilute to the scale with water, fill well, let stand for 40 min. Use a 30 mm cuvette to measure the absorbance at a wavelength of 385 or 430 nm on a spectrophotometer, with the reagent blank solution as the reference, and draw the standard curve. Determination
Accurately transfer 25 ml of the silicon-free filtrate into a 100 ml volumetric flask, add 2 ml of ascorbic acid solution (2%), and mix well. Let stand for 3-5 minutes, add 10 ml of diantipyrine methane solution (4%), 16 ml of hydrochloric acid (1+1), dilute to the mark with water, and mix well. Let stand for 40 minutes. Use a 30 mm colorimeter at a wavelength of 385 or 430 nm on a spectrophotometer. Take the blank test as a reference and measure its absorbance. The percentage content of titanium difluoride is calculated according to formula (5): T,O: (percentage content) =
m,×10-*
×100%
Where: #; — mass of titanium dioxide obtained from the standard curve, g: mass of the sample, g
25——volume of the test solution, ml;
250——total volume of the test solution, ml.
Determination of aluminum oxide
1. Method summary
Add excess EDTA standard solution to complex with aluminum, iron and titanium, control the pH of the solution to 5-6, use xylenol orange as indicator, use zinc standard solution to determine the remaining EDTA, use potassium fluoride to replace the EDTA complexed with aluminum and titanium, continue to titrate with zinc standard solution, and thereby determine the total amount of aluminum oxide and titanium dioxide. Subtract the amount of titanium dichloride measured by spectrophotometry from the total amount to obtain the content of aluminum trioxide.
8.2 Reagents
Nitrogen water; (1+1);
Hydrochloric acid: (1+1);
Hexamethylenetetramine;
Para-butylphenol indicator: (0.1%);
Xylenol orange indicator (0.5%): weigh 0.05k xylenol orange and 10g sodium oxide that has been calcined at 500C for 1h and cooled to room temperature in a desiccator, put them into a mortar and grind them into a fine powder, mix them well, put them into a weighing bottle, and store them in a desiccator; Zinc acetate standard solution: weigh 4.4g zinc acetate in a 400ml beaker, add Dissolve in water, add 5ml glacial acetic acid, transfer to a 1L volumetric flask, dilute with water to the scale, mix, transfer to a plastic bottle for calibration; EDTA standard solution: weigh 7.45g of ethylenediaminetetraacetic acid disodium in a 400ml beaker, add 250ml hot water to dissolve, after cooling to room temperature, dilute with water to L, transfer to a plastic bottle for calibration: Aluminum standard solution (0.02mol/L): weigh 0.5396g of metal aluminum foil (99.999%) in a 250ml tall beaker, add 25ml hydrochloric acid, 5ml nitric acid, cover with a watch glass, slowly heat on an electric furnace to dissolve, after the metal aluminum is completely dissolved, wash the surface III with water, and continue heating for 10min. Remove it, cool it to room temperature, transfer it to a volumetric flask, dilute it with water to the scale, mix it, and transfer it to a plastic bottle: Determination of the volume ratio of EDTA standard solution to zinc acetate standard solution: release 25mEDTA standard solution from the burette into a 300ml flask, add 1 drop of p-nitrophenol indicator (0.1%), adjust it with ammonia water (1+1) until the solution turns yellow, then add hydrochloric acid (1+1) to make the solution colorless, and add 2 drops in excess, add 1g of hexamethylenetetramine, add about 80ml of water, a little xylenol orange indicator, and titrate with zinc acetate standard solution 6
JB/T5893.6-1991
. The end point is when the solution suddenly turns red, and the milliliters of zinc acetate standard solution consumed are recorded. The volume ratio of EDTA standard solution to zinc acetate standard solution is calculated according to formula (6): K
Wherein: K—the number of milliliters of disodium ethylenediaminetetraacetic acid standard solution equivalent to each milliliter of zinc acetate standard solution; V—the volume of zinc acetate standard solution consumed during titration, ml; 25——the number of milliliters of disodium ethylenediaminetetraacetic acid standard solution discharged from the burette. (6)
Standardization of EDTA standard solution: Accurately transfer 25 ml of aluminum standard solution into a 300 ml conical flask, discharge 40 ml of EDTA standard solution from the burette, and heat and boil on an electric stove for 1 min. Remove it, add 1 drop of p-nitrophenol indicator (0.1%), adjust the solution to yellow with ammonia water (1+1), and then add hydrochloric acid (1+1) to make the solution colorless, and add two drops in excess. Put it on the electric stove and boil for 5 min. Cool it to room temperature with running water. Add 1 g of hexamethylenetetramine and a small amount of xylenol orange indicator (1%). Titrate with zinc acetate standard solution until the solution suddenly turns red, which is the end point. Record the milliliters of zinc acetate standard solution consumed. The titration degree of EDTA standard solution on aluminum oxide is calculated according to formula (7): TA,o,
0.02X50.98
Wherein: TAO,
The titration degree of disodium ethylenediaminetetraacetic acid standard solution on aluminum oxide, mg/ml; -Concentration of aluminum standard solution, mol/L;
50.98——half of the molar mass of aluminum oxide; g/mol, 40—The volume of disodium ethylenediaminetetraacetic acid standard solution released from the burette, ml; V—The volume of zinc acetate standard solution consumed, ml; The volume of aluminum standard solution, ml;
K---The number of milliliters of disodium ethylenediaminetetraacetic acid standard solution equivalent to each milliliter of zinc acetate standard solution. 8.3 Analysis steps
8.3.1 Blank test
Carry out a blank test together with the sample, and the reagents used must be taken from the same reagent bottle. 8.3.2 Determination
Accurately transfer 50ml of the desiliconized filtrate into a 300ml conical flask, release 30ml of the EDTA standard solution from the burette, and heat and boil on an electric stove for 1min. Remove it, add 1 drop of p-nitrophenol indicator (0.1%), adjust the solution to yellow with ammonia water (1+1), and then add hydrochloric acid (1+1) to make the solution colorless, and add 2 drops in excess. Boil it on an electric stove for 5min. Cool it to room temperature with running water. Add 1g of hexamethylenetetramine and a little xylenol indicator. Titrate with zinc acetate standard solution to make the solution suddenly turn red. Add 1g of potassium fluoride, continue to boil on the electric stove for 1min, remove it, and cool it to room temperature with running water. Titrate with zinc acetate standard solution until it turns red, which is the end point. Record the milliliters of zinc acetate standard solution consumed after adding potassium fluoride.
The percentage of aluminum oxide is calculated according to formula (8): Tuo,(VV.)K
Al,O (percentage):
Wherein: TA,o,
m×1000
×100%=0.6381×Ti0, (percentage) The titration degree of disodium ethylenediaminetetraacetic acid standard solution on aluminum oxide, mg/ml; The volume of zinc acetate standard solution consumed in the titration blank test, ml; V —The volume of zinc acetate standard solution consumed in titrating the sample solution, ml; K The number of milliliters of disodium ethylenediaminetetraacetic acid standard solution equivalent to each liter of zinc acetate standard solution; TiO, (percentage) —The percentage of titanium dioxide in the sample; 0.6381----The coefficient for converting titanium dioxide into aluminum oxide; m
Sample mass, g:
50-—The volume of the test solution taken out, ml
250-The total volume of the test solution, ml.
9 Determination of calcium oxide and magnesium oxide
9.1 Summary of the method
JB/T5893.6-1991
Take the filtrate after silicon removal, add strontium oxide as a release agent, and measure the absorbance of calcium and magnesium respectively at 285.2nm with a wavelength of 422.7 on an atomic absorption spectrophotometer using an air-acetylene flame. 9.2 Reagents
Hydrochloric acid: (1+1) high-grade pure;
Strontium chloride solution (10%): Weigh 100g of high-grade pure strontium fluoride hexahydrate (SrCI·6H,O), dissolve in water, transfer to a 1L volumetric flask, dilute with water to the mark, and mix. Store in a plastic bottle for later use; Calcium oxide standard storage solution: Weigh 1.7848g of calcium carbonate (reference reagent) pre-dried at 140℃ for 2h, place in a 250ml tall beaker, add about 100ml of water, cover the surface with blood, drip 10ml of hydrochloric acid from the mouth of the beaker to dissolve, heat and boil to drive out carbon dioxide. Remove, cool, transfer to a 1L volumetric flask, dilute with water to the mark, and mix. This solution contains 1mg calcium oxide per milliliter. Store in a plastic bottle; Standard magnesium oxide storage solution: weigh 1.0000g of reference magnesium oxide that has been burned at 800-820℃ for 1h and cooled to room temperature, place it in a 250mm high beaker, add about 50ml of water, cover with blood, drip hydrochloric acid (1+1) from the mouth of the cup to make it completely dissolved, heat and boil for a while. Remove, cool, transfer to a 1L volumetric flask, dilute with water to the scale, and mix. This solution contains 1mg magnesium oxide per milliliter and is stored in a plastic bottle; Calcium oxide-magnesium oxide mixed standard solution: accurately transfer 100ml of the above calcium oxide standard storage solution and 10ml of the above magnesium oxide standard storage solution, place them in a 1L volumetric flask, dilute with water to the scale, and mix. This solution contains 100ug calcium oxide and 10g magnesium oxide per milliliter and is stored in a plastic bottle.
Calcium oxide-magnesium oxide mixed standard series solution; accurately transfer 0, 1.00, 2.00, 4.00, 6.00, 8.00, 10.00ml of the above mixed standard solution, respectively placed in a group of 100ml volumetric flasks, add 25ml blank test, 5ml strontium oxide solution (10%), dilute to scale with water, and mix well. Transfer to 100ml plastic bottles respectively. This series of solutions contains 0, 1.00, 2.00, 4.00, 6.00, 8.00, 10.00μg calcium oxide and 0, 0.10, 0.20, 0.40, 0.60, 0.80, 1.00ug magnesium oxide per milliliter. 9.3 Instrument
Atomic absorption spectrophotometer.
9.4 Analysis steps
9.4.1 Blank test
Carry out a blank test together with the sample, and the reagents used must be taken from the same reagent bottle. 9.4.2 Determination
Accurately transfer 25 ml of the desiliconized filtrate to a 100 ml volumetric flask, add 5 ml of strontium oxide solution (10%), dilute to the scale with water, and mix well.
Adjust the atomic absorption spectrophotometer to the working state according to the operating procedures of the instrument used. Select appropriate instrument parameters (slit width, lamp current, burner height, flame state, gain amplification, logarithmic conversion, curve straightening, scale expansion, etc.), use calcium and magnesium hollow cathode lamps, air-acetylene flame, at 422.7 and 285.2 nm wavelengths, and determine calcium oxide and magnesium oxide respectively according to the following operations. Spray the zero solution of the mixed standard series to zero the instrument; spray the sample solution and read the absorbance (D); from the mixed standard series solution, select a standard solution with a slightly lower concentration than the sample solution for spraying and read the absorbance (D,). Then select a standard solution with a slightly higher concentration than the sample solution for spraying and read the absorbance (D,). The percentage of calcium oxide and magnesium oxide is calculated according to formula (9); [C, + (C, -- C,)
CaO or MgO (percentage)
J×V×10-5
D, - D,
Where; C, - the concentration of the standard solution slightly lower than the sample solution, \g/ml; C, - the concentration of the standard solution slightly higher than the sample solution, μg/ml; V - the volume of the sample solution during the measurement, ml; 8
The mass of the sample taken, g.
10 Determination of potassium oxide and sodium oxide
10.1 Summary of the method
JB/T5893.6-1991
The sample is decomposed with hydrochloric acid and nitric acid to make a hydrochloric acid solution, which is sprayed on a flame photometer and excited by a flame. The radiation to be measured is projected onto a photocell through potassium and sodium interference filters and converted into a photocurrent, which is measured by a galvanometer. 10.2 Reagents
Nitric acid: (1+1);
Hydrochloric acid: (1+1); (1+11):
Aluminum standard solution: Weigh 1g of refined aluminum chips (99.99%), place in a 250ml tall beaker, add 50ml of hydrochloric acid (1+1) and 5ml of nitric acid (1+1), cover with a watch glass, and heat at low temperature until all dissolved. Remove and clean the watch glass, continue heating, and evaporate to dryness. Remove and cool. Add 10ml hydrochloric acid and transfer to a 1L volumetric flask. Dilute with water to the mark and mix. Store in a plastic bottle that has been pre-cleaned with dilute hydrochloric acid. This solution contains 1mg aluminum per milliliter.
Standard potassium oxide storage solution: weigh 1.5829g of potassium oxide (reference reagent) that has been pre-burned at 400-450℃ for 1.5h, place it in a 250ml tall beaker, add water to dissolve, transfer to a 1L volumetric flask, dilute with water to the mark and mix. Store in a plastic bottle that has been pre-cleaned with dilute hydrochloric acid. This solution contains 1mg potassium oxide per milliliter; Standard sodium oxide storage solution: weigh 0.9429g of sodium oxide (reference reagent) that has been pre-burned at 400450℃ for 1.5h, place it in a 250ml tall beaker, add water to dissolve, transfer to a 1L volumetric flask, dilute with water to the mark and mix. Store in a plastic bottle that has been pre-cleaned with dilute hydrochloric acid. This solution contains 0.5mg sodium oxide per ml; Potassium oxide-sodium oxide mixed standard series solution: add 0, 5.00, 5.30, 5.50, 5.80, 6.00, 6.50, 6.80, 7.00ml of the above potassium oxide standard stock solution from a 10ml semi-micro burette to 10 100ml volumetric flasks containing 50ml blank test, and add 0, 4.60, 4.20, 4.00, 3.60, 3.00, 2.60, 2.00, 1.60, 1.00ml of the above sodium oxide standard stock solution from another 10ml semi-micro burette to the above volumetric flask. Add 5ml of the above aluminum standard solution to each, dilute to the scale with water, and mix well. Store in a 100ml plastic bottle that has been pre-cleaned with dilute hydrochloric acid. This standard series of solutions contains 0, 5.00, 5.30, 5.50, 5.80, 6.00, 6.30, 6.50, 6.80, 7.00 mg of oxide and 0, 2.30, 2.10, 2.00, 1.80, 1.50, 1.30, 1.00, 0.80, 0.50 mg of sodium oxide in 100 ml.
10.3 Apparatus
Flame photometer.
10.4 Analytical procedures
10.4.1 Blank test
Carry out a blank test together with the sample, and the reagents used must be taken from the same reagent bottle. 10.4.2 Determination
Weigh 0.1g of the dried sample in a platinum dish, add 10 drops of nitric acid (1+1) to moisten it, then add 10ml of hydrofluoric acid (40%), place it on a sand bath and heat it to dry in the evaporation chamber, then add 5 drops of nitric acid (1+1) and 5ml of hydrofluoric acid (40%) to evaporate to dryness, and continue to increase the temperature to dry for 10min. Remove and cool, add 16ml of hydrochloric acid (1+11), and heat to fully dissolve. After cooling, transfer the sample solution into a 200ml volumetric flask, and the blank test into a 100ml volumetric flask, dilute with water to the scale, and mix well. Adjust the flame photometer to the working state according to the instrument usage regulations, and perform the following operations, using a potassium filter (wavelength 767nm) to determine potassium and a sodium filter (wavelength 589nm) to determine sodium. Spray the mixed standard series of equal solutions to zero the instrument; spray the sample solution and read the galvanometer reading (D); from the potassium oxide and sodium oxide mixed standard series solutions, select a standard solution with a slightly lower concentration than the sample solution and spray it, and read the galvanometer reading (D,). Then select a standard solution with a slightly higher concentration than the sample solution and spray it, and read the galvanometer reading (D,). The percentage of potassium oxide and sodium oxide is calculated according to formula (10): 9
K,O or Na,O (percentage)
JB/T5893.6-1991
DD:J×2×10-
[C, + (C, - C,)
D, - D,
× 100%
C,—concentration of standard solution slightly lower than that of sample solution, mg/100ml; Where:
C,—concentration of standard solution slightly higher than that of sample solution, mg/100ml; m-mass of sample, g;
2-——ratio of the volume of the measured sample solution to the volume of the mixed standard series solution. 11
The allowable difference of the analysis results shall comply with the provisions of the following table: Allowable difference of the analysis results
Loss on ignition
Additional instructions:
>0.50~1.00
60.00~70.00
0.050~0.250
>0.25~0.50
17.00~21.00
0.010~0 .050
>0.050~0.100
>0.10~0.50
>0.050~0.100
>0.10~0.50
>0.50~1.00
>1.50~3.50
This standard is proposed by the National Technical Committee for Standardization of Insulators and is under the jurisdiction of the Xi'an Insulator Research Institute of the Ministry of Electronics Industry. This standard was drafted by the Xi'an Insulator Research Institute. The main drafters of this standard are Li Guangfu and Pi Huijie.
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