GB/T 4984-1985 Chemical analysis methods for zirconium corundum refractory materials
Some standard content:
National Standard of the People's Republic of China
GB/T4984-1985
Chemical Analysis Method of Corundum Refractory Materials
1985-12-01 Implementation
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《Chemical Analysis Method of Zirconia Corundum Refractory Materials》Material Code
4984-1985
1 General Principles,
2 Sample Preparation
3 Determination of Ignition Loss,
4 Determination of Silicon Dioxide
5 Determination of Aluminum Oxide
6 Determination of Zirconium Dioxide and Hafnium Dioxide Contents 8 Potassium Oxide, Sodium Oxide, Determination of calcium oxide, magnesium oxide and ferric oxide 9 Allowable error of analysis results
Appendix A
Appendix B Standard sample
Additional notes:
(Reference sample)
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Chemical analysis method of corundum refractory materials》
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This standard is applicable to the chemical analysis of zirconium corundum refractory materials
Chemical analysis method of corundum refractory materials
4984-1985
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1.1 The analysis samples should be dried at 105-110℃ for 1-2h, then placed in a desiccator and cooled to room temperature before weighing. 1.2 The water used for chemical analysis should be distilled water or deionized water; the water used for atomic absorption analysis should be twice deionized water or water of equivalent purity. The chemical reagents used should be analytically pure or superior; the chemical reagents used for calibration should be reference reagents or high ec.
1.4 The percentage concentration of the solution is the weight-volume percentage concentration, which refers to the number of grams of solute contained in 100 ml of solution. 11 General Principles
1.7 During arbitration analysis, the number of parallel copies of the same sample shall not be less than two. When the difference in the analysis results is within the allowable error range, 1.3 The sensitivity of the analytical balance should reach 0.1 mg. The balance code should be calibrated regularly. 1.5 The burette, volumetric flask, pipette and other measuring instruments must be calibrated. +1, +3, +1+n, etc. refer to the ratio of the solute volume to the water volume. 1.6 A blank test should be performed simultaneously in each determination to calibrate the analysis results. Pure reagent.
The arithmetic mean is taken as the final analysis result. Zirconium
Chemical Analysis Methods for Refractory Materials》
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2 Sample PreparationwwW.bzxz.Net
According to the sample preparation requirements, finally take 15-20 grams of the sample and grind it until it all passes through the 180-mesh standard sieve. Sinoaec.
Refractory Materials Chemistry
Corundum Surface
4984-1985
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3 Determination of Loss on Ignition
Accurately weigh about 1 gram of sample and place it in platinum or porcelain that has been calcined to constant weight at 950-1000℃ in advance, cover it, leave a little space, place it in a high-temperature furnace, start from low temperature and heat it to 950-1000℃ and calcine for 1 hour, take it out, place it in a desiccator, cool it to room temperature, and weigh it. Repeatedly burn and weigh until constant weight. The percentage of loss on ignition is calculated according to formula (1): G1-G2
Loss on ignition %=
Wherein: G1-crumb and sample before ignition, g; G2-crumb and sample after ignition, g:
-sample weight, g.
·(1)
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Corundum surface
Refractory chemical analysis square bath
4984-1985
4.1 Reagents
4 Determination of silicon dioxide
4.1.1 Hydrochloric acid: 1+1; 1+4; 1N.
4.1.2 Anhydrous ethanol.
4.1.3 Sulfuric acid: 1+1
4.1.4 Potassium fluoride: 2% aqueous solution.
4.1.5 Boric acid: 2% aqueous solution.
4.1.6 Ammonium molybdate: 7% aqueous solution, filter and store in a plastic bottle for later use. 4.1.7 0.25% ascorbic acid solution: weigh 0.25g ascorbic acid, dissolve it with a little water, add sulfuric acid (1+1) to 100ml (prepare it when needed).
4.1.8 Borax-sodium carbonate mixed flux: 1:2 (weight ratio). 4.1.9 Silicon dioxide standard solution: accurately weigh 0.1000g of high-purity silicon dioxide that has been calcined at 950-1000℃ for 1 hour, place it in platinum, add 4g of borax-sodium carbonate mixed flux, melt at 950-1000℃ until transparent, remove it immediately and cool it slightly, and soak the melt in hot water in a plastic beaker. After the solution is clear and cooled to room temperature, transfer it to a 1000 ml volumetric flask, dilute it to the mark with water, shake it well, and immediately transfer it to a dry plastic bottle for storage. This solution contains 0.1 mg of silicon dioxide per ml.
4.1.10 Sodium hydroxide: 20% aqueous solution, stored in a plastic bottle. 4.1.11 p-Nitrophenol: 0.5% ethanol solution. 4.2 Drawing of the working curve
In a group of 100 ml plastic cups, add 0.00, 1.00, 2.00, 3.00, .:::::. 6.00 ml of silicon dioxide standard solution (0.1 mg/ml), add 5 ml of 2% potassium fluoride, shake it well, and let it stand for 10 minutes. Add 5 ml of 2% boric acid, 1 drop of 0.5% p-nitrophenol, adjust with 20% sodium hydroxide until the solution turns yellow, add 7 ml of 1N hydrochloric acid and 10 ml of anhydrous ethanol, and then add 5 ml of 7% ammonium molybdate, and place at 20-30°C for 20 minutes. Transfer to a 100 ml volumetric flask and dilute to about 80 ml. Add 10 ml of 0.25% ascorbic acid solution, dilute to scale with water, shake well, and place for 90 minutes. Use 0.5 cm colorimetric blood on a spectrophotometer, use the reagent blank as a reference, measure its absorbance at a wavelength of 680 nanometers, and draw a working curve. 4.3 Analysis steps
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(Chemical analysis methods for refractory materials)
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Accurately weigh about 0.05 grams of the sample, place it in a platinum crucible, add 2 grams of borax-sodium carbonate mixed flux, mix the flux and the sample evenly, then add 2 grams of mixed flux to cover the surface of the sample, melt at 950-1000℃ until transparent, and continue to melt for 5-10 minutes. After cooling, rinse the outer wall with hot water, put it in a 300 ml beaker pre-filled with 50 ml of hydrochloric acid (1 + 4), and heat it. After the frit is dissolved, wash it, cool it, transfer it to a 250 mL volumetric flask, dilute it to the scale with water, shake it well, and set it aside. Take 10-15mL of the above solution, put it in a 100mL plastic cup, add 5mL of 2% potassium fluoride, shake well, leave it for 10min, add 5mL of 2% boric acid and 4mL of 1N hydrochloric acid, shake well, add 10mL of anhydrous ethanol, and perform the following operations according to step 4.2.
The percentage of silicon dioxide is calculated according to formula (2): SiO2%=
+........
-The amount of silicon dioxide in the test solution is obtained from the working curve, mg: Where: C-
V-the volume of the test solution taken, milliliter;
G-the weight of the sample, g.
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Chemical Analysis Methods for Corundum Refractory Materials》
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5.1 Reagents
5 Determination of Aluminum Oxide
5.1.1 Copper-iron reagent: 6% aqueous solution, filter and set aside. 5.1.2 Chloroform.
5.1.3 Hydrochloric acid: specific gravity 1.19, 1+1.
5.1.4 p-Nitrophenol: 0.5% ethanol solution. 5.1.5 1-(2-pyridylazo)-2-naphthol (PAN): 0.2% ethanol solution, weigh 0.1 g PAN and dissolve it in ethanol solution, dilute to 50 ml with ethanol.
5.1.6 Ammonium hydroxide: specific gravity 0.9, 1+1. 5.1.7 Acetic acid-sodium acetate buffer solution: weigh 32g of anhydrous sodium acetate, add 60ml of glacial acetic acid, dilute with water to 1000ml, the pH of this solution is about 4.3.
5.1.8 Copper sulfate standard solution: 0.01M. Weigh 2.49g of copper sulfate (CuS04.5H20) and dissolve it in a small amount of water, add 4-5 drops of sulfuric acid (1+1), and dilute with water to 1000ml. 5.1.9 Borax-sodium carbonate mixed flux: 1:2 (weight ratio). 5.1.10 Aluminum oxide standard solution: accurately weigh 0.5000g of high-purity aluminum oxide burned at 950-1000℃ for 1 hour, place it in platinum glass, add 6-7g of borax-sodium carbonate (1:2) mixed flux, and melt at 950-1000℃ until transparent. Continue melting for another 20 minutes, soak the molten mass with 30 ml of hydrochloric acid (1+1), and heat until the molten mass is completely dissolved. After cooling, transfer to a 500 ml volumetric flask, dilute to scale with water, and shake to hook. This solution contains 1 mg of aluminum oxide per ml. 5.1.11 EDTA standard solution: 0.01 M. Weigh 3.6 grams, dissolved in a small amount of water, diluted with water to 1000 ml.
5.1.12 Determination of the titer of aluminum oxide with EDTA standard solution: Accurately take 10 ml of the above aluminum oxide standard solution, put it into a 300 ml beaker, add 25-30 ml of 0.01 EDTA standard solution, and dilute it with water to about 150 ml. Add 2 drops of 0.5% p-nitrophenol, adjust with ammonium hydroxide (1+1) until the solution turns yellow, then adjust with hydrochloric acid (1+1) until it is colorless, add 10 ml of acetic acid-sodium acetate buffer solution with a pH of 4.3, heat and boil for 3 minutes, cool slightly, add 5 drops of 0.2% PAN indicator, and immediately back-titrate with 0.01M copper sulfate standard solution until the color changes from yellow to purple, which is the end point.
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Chemical Analysis Methods for Refractory Materials)
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Accurately pipette 10 ml of 0.01M EDTA standard solution into a 250 ml beaker, add water to about 150 ml, add 10 ml of acetic acid-sodium acetate buffer solution (PH 4.3), boil for 3 minutes. Cool to 80-90℃, add 2-3 drops of 0.2% PAN indicator, and immediately titrate with 0.01M copper sulfate standard solution until purple, which is the end point. The titer of aluminum oxide is calculated according to formula (3): Cx10
TAL203=
Wherein: C
concentration of aluminum oxide standard solution, mg/ml: volume of EDTA standard solution added, ml: volume of copper sulfate standard solution consumed during titration, ml; volume of aluminum oxide standard solution, ml; ··.(3
the volume ratio of each milliliter of copper sulfate standard solution to EDTA standard solution. The volume ratio K is calculated according to formula (4):
Wherein: V
5.2 Analysis steps
volume of copper sulfate standard solution consumed during titration, ml. (4)
Accurately weigh about 0.3 grams of the sample, put it into a platinum crucible, add 3 grams of borax-sodium carbonate mixed flux, mix it with the sample, and then add 3 grams of mixed flux to cover the surface of the sample, and melt it at 950-1000℃. After melting to transparency, continue melting for 15-20 minutes. Remove and cool, rinse the outer wall of the crucible with water, and put it and the frit into a 150 ml beaker pre-filled with 25 ml hot hydrochloric acid (1 + 1), and heat it to dissolve. When the solution is clear and transparent, take out the crucible, rinse it with water, cool it, transfer it to a 250 ml volumetric flask, dilute it to the scale with water, shake it well, and set it aside. This solution is test solution A. ||tt| |Accurately pipette 25 ml of test solution A into a 150 ml separatory funnel, add 10 ml of 1+1 hydrochloric acid, dilute to 60 ml with water, and shake. Add 3 ml of 6% copper iron reagent, shake, and immediately add 15 ml of chloroform, shake vigorously and extract for 1 minute. Let stand and separate. Discard the organic phase. Add 2-3 drops of 6% copper iron reagent, and immediately add 5-10 ml of chloroform, and extract for 1 minute. Let stand and separate, and discard the organic phase (if the organic phase is yellow, it needs to be extracted again). Transfer the aqueous phase into a 300 ml beaker, wash the separatory funnel with water, accurately add 30 ml of 0.01M EDTA standard solution (depending on the amount of aluminum), and heat to 60-70℃, add 2 drops of 0.5% p-nitrophenol, then add 4 ml of ammonium hydroxide (0.9 heavier than Page 10
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) solution, then use ammonium hydroxide (1+1) to adjust the solution to yellow, then use hydrochloric acid (1+1) to adjust it to colorless, add 10 ml of acetic acid-sodium acetate buffer solution with a pH of 4.3, heat and boil for 2-3 minutes, cool slightly, add 2-3 drops of PAN indicator, and immediately use 0.01M copper sulfate standard solution to back titrate until purple, which is the end point. The percentage of aluminum oxide is calculated according to formula (5): TAL203(V1 -V2. K)X10
AL203%=
GX1000
X100.....(5)
Wherein: TAL203---the titration degree of EDTA standard solution on aluminum oxide, mg/ml: V1-
the volume of EDTA standard solution added, ml; the volume of copper sulfate standard solution consumed during titration, ml: the volume ratio of each ml of copper sulfate standard solution equivalent to EDTA standard solution: the volume ratio of the whole test solution to the test solution taken; the weight of the sample, g.
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6.1 Reagents
6 Determination of Zirconium Dioxide and Hafnium Dioxide Contents 6.1.1 Sulfuric Acid: 1+4.
6.1.2 Hydrofluoric Acid: 40%.
6.1.3 Hydrochloric acid: specific gravity 1.19, 1+1.
6.1.4 Jasmine glycolic acid (mandelic acid): solid. 6.1.5 Mandelic acid washing solution: 5% aqueous solution. Weigh 5 grams of mandelic acid, add 2 milliliters of concentrated hydrochloric acid, and dilute with water to 100 milliliters.
6.1.6 Borax-sodium carbonate mixed flux: 2:1 (weight ratio). 6.1.7 Ethanol: 95%.
6.2 Analysis steps
Accurately weigh about 0.3 grams of the sample, place it in a platinum pot, moisten it with water, add 1-1.5 milliliters of sulfuric acid (1+4), and then add 5 milliliters of 40% hydrofluoric acid, evaporate it on a low-temperature electric furnace until it is almost dry, and repeat the process once. Raise the temperature until all the sulfur trioxide white smoke is emitted. Add 4-5 g of borax-sodium carbonate mixed flux to the residue, melt at 950-1000°C until transparent, continue melting for 15-20 minutes, and dissolve the frit with 25 ml of hot hydrochloric acid (1+1). After all dissolved, cool, transfer to a 250 ml volumetric flask, dilute to scale with water, shake, and set aside. This solution is test solution B. Take 100 ml of test solution B, place it in a 300 ml beaker, add 20 ml of hydrochloric acid (specific gravity 1.19), adjust the volume to about 120 ml, and heat to 80-85°C (on a water bath). Slowly add 6-7 g of bitter benzyl acid while stirring, place it on a water bath to keep warm for half an hour, remove it, and let it stand for 3-4 hours. Filter with slow paper, wash with mandelic acid detergent 8-10 times, wash with water 3-5 times, and then wash with a little 95% ethanol 1-2 times. Put the precipitate and filter paper into platinum that has been burned to constant weight, dry and ash, burn in a 950℃ high-temperature furnace for 30 minutes, take out and put into a dryer to cool to room temperature, and weigh. Repeat the burning until constant weight. The percentage of zirconium dioxide and hafnium dioxide is calculated according to formula (6): (G1-G2)X2.5
Zr (Hf)02% =
Where: G1-
The weight of the crucible and the precipitate, grams;
The weight of the crucible, grams;
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Chemical Analysis Methods for Refractory Materials
4984-19853 grams, put it in a platinum crucible, add 3 grams of borax-sodium carbonate mixed flux, mix it with the sample, then add 3 grams of mixed flux to cover the surface of the sample, and melt it at 950-1000℃. After melting to transparency, continue melting for 15-20 minutes. Remove and cool, rinse the outer wall of the crucible with water, and put it and the frit into a 150 ml beaker pre-filled with 25 ml hot hydrochloric acid (1+1), and heat it to dissolve. After the solution is clear and transparent, take out the crucible and wash it with water, cool it, transfer it to a 250 ml volumetric flask, dilute it with water to the scale, shake it well, and set it aside. This solution is test solution A.
Accurately take 25 ml of test solution A, place it in a 150 ml separatory funnel, add 10 ml of 1+1 hydrochloric acid, dilute it with water to 60 ml, and shake it. Add 3 ml of 6% copper iron reagent, shake it, and immediately add 15 ml of chloroform, shake it vigorously and extract it for 1 minute. After standing and stratification. Discard the organic phase. Add 2-3 drops of 6% copper iron reagent, then immediately add 5-10 ml of chloroform and extract for 1 minute. After standing and stratification, discard the organic phase (if the organic phase is yellow, it needs to be extracted again). Transfer the aqueous phase into a 300 ml beaker, wash the separatory funnel with water, accurately add 30 ml of 0.01M EDTA standard solution (depending on the amount of aluminum), heat to 60-70°C, add 2 drops of 0.5% p-nitrophenol, and then add 4 ml of ammonium hydroxide (0.9 heavier than Page 10
Chemical Analysis Methods for Refractory Materials
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) solution, then first use ammonium hydroxide (1 + 1) to adjust the solution to yellow, and then use hydrochloric acid (1 + 1) to adjust to colorless, add 10 ml of acetic acid-sodium acetate buffer solution with a pH of 4.3, heat and boil for 2-3 minutes, cool slightly, add 2-3 drops of PAN indicator, and immediately back titrate with 0.01M copper sulfate standard solution until it turns purple, which is the end point. The percentage of aluminum oxide is calculated according to formula (5): TAL203(V1 -V2. K)X10
AL203%=
GX1000
X100.....(5)
Wherein: TAL203--the titration degree of EDTA standard solution on aluminum oxide, mg/ml; V1-
the volume of EDTA standard solution added, ml; the volume of copper sulfate standard solution consumed during titration, ml; the volume ratio of copper sulfate standard solution per ml equivalent to EDTA standard solution; the volume ratio of the total test solution to the test solution taken; the weight of the sample, g.
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Corundum Refractory Chemical Analysis Square Steam
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6.1 Reagents
6 Determination of zirconium dioxide and hafnium dioxide content 6.1.1 Sulfuric acid: 1+4.
6.1.2 Hydrofluoric acid: 40%.
6.1.3 Hydrochloric acid: specific gravity 1.19, 1+1.
6.1.4 Jasmine glycolic acid (mandelic acid): solid. 6.1.5 Mandelic acid washing solution: 5% aqueous solution. Weigh 5 grams of mandelic acid, add 2 ml of concentrated hydrochloric acid, and dilute with water to 100 ml.
6.1.6 Borax-sodium carbonate mixed flux: 2:1 (weight ratio). 6.1.7 Ethanol: 95%.
6.2 Analysis steps
Accurately weigh about 0.3 g of the sample, place it in a platinum pot, moisten it with water, add 1-1.5 ml of sulfuric acid (1+4), and then add 5 ml of 40% hydrofluoric acid, evaporate it on a low-temperature electric furnace until it is almost dry, and repeat the process once. Raise the temperature until all the white smoke of sulfur trioxide is emitted. Add 4-5 g of borax-sodium carbonate mixed flux to the residue, melt it at 950-1000℃ until it is transparent, continue melting for 15-20 minutes, and dissolve the molten block with 25 ml of hot hydrochloric acid (1+1). After it is completely dissolved, cool it, transfer it to a 250 ml volumetric flask, dilute it to the scale with water, shake it, and set it aside. This solution is test solution B. Take 100 ml of test solution B, place it in a 300 ml beaker, add 20 ml of hydrochloric acid (specific gravity 1.19), adjust the volume to about 120 ml, and heat it to 80-85℃ (on a water bath). Slowly add 6-7 grams of mandelic acid under stirring, place in a water bath for half an hour, remove and let stand for 3-4 hours. Filter with slow paper, wash with mandelic acid washing solution 8-10 times, wash with water 3-5 times, and then wash with a little 95% ethanol 1-2 times. Put the precipitate and filter paper into platinum that has been burned to constant weight, dry and ash, burn in a high-temperature furnace at 950℃ for 30 minutes, take out and put in a desiccator to cool to room temperature, and weigh. Repeat burning until constant weight. The percentage of zirconium dioxide and hafnium dioxide is calculated according to formula (6): (G1 -G2) X2.5
Zr (Hf)02% =
Wherein: G1-
weight of crucible and precipitate, g;
weight of crucible, g;
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Chemical Analysis Methods for Refractory Materials
4984-19853 grams, put it in a platinum crucible, add 3 grams of borax-sodium carbonate mixed flux, mix it with the sample, then add 3 grams of mixed flux to cover the surface of the sample, and melt it at 950-1000℃. After melting to transparency, continue melting for 15-20 minutes. Remove and cool, rinse the outer wall of the crucible with water, and put it and the frit into a 150 ml beaker pre-filled with 25 ml hot hydrochloric acid (1+1), and heat it to dissolve. After the solution is clear and transparent, take out the crucible and wash it with water, cool it, transfer it to a 250 ml volumetric flask, dilute it with water to the scale, shake it well, and set it aside. This solution is test solution A.
Accurately take 25 ml of test solution A, place it in a 150 ml separatory funnel, add 10 ml of 1+1 hydrochloric acid, dilute it with water to 60 ml, and shake it. Add 3 ml of 6% copper iron reagent, shake it, and immediately add 15 ml of chloroform, shake it vigorously and extract it for 1 minute. After standing and stratification. Discard the organic phase. Add 2-3 drops of 6% copper iron reagent, then immediately add 5-10 ml of chloroform and extract for 1 minute. After standing and stratification, discard the organic phase (if the organic phase is yellow, it needs to be extracted again). Transfer the aqueous phase into a 300 ml beaker, wash the separatory funnel with water, accurately add 30 ml of 0.01M EDTA standard solution (depending on the amount of aluminum), heat to 60-70°C, add 2 drops of 0.5% p-nitrophenol, and then add 4 ml of ammonium hydroxide (0.9 heavier than Page 10
Chemical Analysis Methods for Refractory Materials
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) solution, then first use ammonium hydroxide (1 + 1) to adjust the solution to yellow, and then use hydrochloric acid (1 + 1) to adjust to colorless, add 10 ml of acetic acid-sodium acetate buffer solution with a pH of 4.3, heat and boil for 2-3 minutes, cool slightly, add 2-3 drops of PAN indicator, and immediately back titrate with 0.01M copper sulfate standard solution until it turns purple, which is the end point. The percentage of aluminum oxide is calculated according to formula (5): TAL203(V1 -V2. K)X10
AL203%=
GX1000
X100.....(5)
Wherein: TAL203--the titration degree of EDTA standard solution on aluminum oxide, mg/ml; V1-
the volume of EDTA standard solution added, ml; the volume of copper sulfate standard solution consumed during titration, ml; the volume ratio of copper sulfate standard solution per ml equivalent to EDTA standard solution; the volume ratio of the total test solution to the test solution taken; the weight of the sample, g.
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Corundum Refractory Chemical Analysis Square Steam
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6.1 Reagents
6 Determination of zirconium dioxide and hafnium dioxide content 6.1.1 Sulfuric acid: 1+4.
6.1.2 Hydrofluoric acid: 40%.
6.1.3 Hydrochloric acid: specific gravity 1.19, 1+1.
6.1.4 Jasmine glycolic acid (mandelic acid): solid. 6.1.5 Mandelic acid washing solution: 5% aqueous solution. Weigh 5 grams of mandelic acid, add 2 ml of concentrated hydrochloric acid, and dilute with water to 100 ml.
6.1.6 Borax-sodium carbonate mixed flux: 2:1 (weight ratio). 6.1.7 Ethanol: 95%.
6.2 Analysis steps
Accurately weigh about 0.3 g of the sample, place it in a platinum pot, moisten it with water, add 1-1.5 ml of sulfuric acid (1+4), and then add 5 ml of 40% hydrofluoric acid, evaporate it on a low-temperature electric furnace until it is almost dry, and repeat the process once. Raise the temperature until all the white smoke of sulfur trioxide is emitted. Add 4-5 g of borax-sodium carbonate mixed flux to the residue, melt it at 950-1000℃ until it is transparent, continue melting for 15-20 minutes, and dissolve the molten block with 25 ml of hot hydrochloric acid (1+1). After it is completely dissolved, cool it, transfer it to a 250 ml volumetric flask, dilute it to the scale with water, shake it, and set it aside. This solution is test solution B. Take 100 ml of test solution B, place it in a 300 ml beaker, add 20 ml of hydrochloric acid (specific gravity 1.19), adjust the volume to about 120 ml, and heat it to 80-85℃ (on a water bath). Slowly add 6-7 grams of mandelic acid under stirring, place in a water bath for half an hour, remove and let stand for 3-4 hours. Filter with slow paper, wash with mandelic acid washing solution 8-10 times, wash with water 3-5 times, and then wash with a little 95% ethanol 1-2 times. Put the precipitate and filter paper into platinum that has been burned to constant weight, dry and ash, burn in a high-temperature furnace at 950℃ for 30 minutes, take out and put in a desiccator to cool to room temperature, and weigh. Repeat burning until constant weight. The percentage of zirconium dioxide and hafnium dioxide is calculated according to formula (6): (G1 -G2) X2.5
Zr (Hf)02% =
Wherein: G1-
weight of crucible and precipitate, g;
weight of crucible, g;
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Chemical Analysis Methods for Refractory Materials
4984-198519) 20 ml, adjust the volume to about 120 ml, heat to 80-85℃ (on a water bath). Slowly add 6-7 grams of mandelic acid while stirring, place on a water bath to keep warm for half an hour, remove, and let stand for 3-4 hours. Filter with slow paper, wash 8-10 times with mandelic acid washing solution, wash 3-5 times with water, and then wash 1-2 times with a little 95% ethanol. Put the precipitate and filter paper into platinum that has been burned to constant weight, dry and ash, burn in a high-temperature furnace at 950℃ for 30 minutes, take out and put in a desiccator to cool to room temperature, and weigh. Repeat the burning until constant weight. The percentage of zirconium dioxide and hafnium dioxide is calculated according to formula (6): (G1 -G2) X2.5
Zr (Hf)02% =
Wherein: G1-
weight of crucible and precipitate, g;
weight of crucible, g;
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Chemical Analysis Methods for Refractory Materials
4984-198519) 20 ml, adjust the volume to about 120 ml, heat to 80-85℃ (on a water bath). Slowly add 6-7 grams of mandelic acid while stirring, place on a water bath to keep warm for half an hour, remove, and let stand for 3-4 hours. Filter with slow paper, wash 8-10 times with mandelic acid washing solution, wash 3-5 times with water, and then wash 1-2 times with a little 95% ethanol. Put the precipitate and filter paper into platinum that has been burned to constant weight, dry and ash, burn in a high-temperature furnace at 950℃ for 30 minutes, take out and put in a desiccator to cool to room temperature, and weigh. Repeat the burning until constant weight. The percentage of zirconium dioxide and hafnium dioxide is calculated according to formula (6): (G1 -G2) X2.5
Zr (Hf)02% =
Wherein: G1-
weight of crucible and precipitate, g;
weight of crucible, g;
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