Some standard content:
Standard HG 1--1546--84 of Ministry of Chemical Industry of the People's Republic of China was adjusted to: HG/3ss-8y
Analysis method of light oil steam reforming catalyst
Published on September 4, 1984
Implementation on October 1, 1985
Approved by Ministry of Chemical Industry of the People's Republic of China 2
Product preparation
Preparation of sample solution
Determination of nickel content
Determination of aluminum content
Determination of calcium ions
Determination of magnesium content
Determination of iron ions
Determination of the content of iodine.
Test Methods of Ministry of Industry and Information Technology
Test Methods of Concepts
Appendix A
Preparation of Standard Liquid
(6)
Standard of the Ministry of Chemical Industry of the People's Republic of China: Analytical Method for Light Oil Steam Reforming Catalyst
HG 1—1546--84
Adjusted to HG33555-1984
This standard applies to the chemical composition of light oil steam reforming catalysts of type Z301, Z401, Z402, Z404 and 7.405. 1. Preparation of Samples
Crush and mix the slices. Take about 20 g by quartering. Crush to a particle diameter of about 3 mm. Take about 10 g by quartering again. Continue to grind until all of them pass through a 120 sieve. Then put them into a weighing bottle and dry them at 105-110℃ for 2 hours. Then put them in a steam desiccator. 2 Preparation of sample solution
2.1 Method summary
The sample is melted with borax and carbonic acid, and then acid-leached and placed in a container for component analysis. 2.2 Reagents
2.2.1 Borax-sodium carbonate mixed flux (1+1): Weigh appropriate amounts of borax (GB632-78) and anhydrous sodium carbonate (GB639-77), grind and mix.
2.2.2 Hydrochloric acid (GB622-77): 1+1 solution. 2.3 Instruments
Platinum, 30-50 milliliters.
2.4 Operation steps
Accurately weigh 0.2000 g of the sample prepared according to Chapter 1 of this standard, place it in a crucible containing 6 g of borax-sodium carbonate mixed flux, mix it with a red-headed glass rod, wipe the glass with a small piece of fixed filter paper, put the filter paper in the crucible, cover it with 2 g of borax-sodium carbonate mixed flux, and then close the lid. After it is solid, put it in a high-temperature furnace and heat the room temperature to 950U℃ to melt for 1 hour. Take it out and cool it, then put it in a 25 ml beaker, add 45 ml of 1+1 hydrochloric acid, heat it slightly, and after the melt is completely soaked, wash it with hot water to remove and eliminate it, slightly heat the liquid to make it transparent, cool it, transfer it to 250 ml of water, dilute it to the scale, and spread it evenly. 3 Determination of nickel content
3.1 Summary of the method
At pH not! In the slightly acidic solution of the factory 3, nickel is titrated with EDTA standard solution. Alkali metals and a small amount of divalent and valent iron do not interfere with the determination. The needle can be masked with ammonium fluoride. The small amount of valent iron can be reduced to 1-valent iron in advance to eliminate interference. Using PAR as an index, adding a small amount of ethylamine copper tetraacetate can make the end point clearer. Because the reaction is very slow, the titration needs to be carried out in a hot solution. 3.2 Reagents
3.2.1 Ammonia water (GB631-77): 1+1 solution. 3.2.2 Glacial acid (GB 67678).
3.2.3 Amine (HG3-967-76): 10% solution 3.2.4 Fluorinated amine (GB1276-77): 20% solution. Store in a plastic bottle. 3.2.5 Pyrrolidine-(2-azo-4) octyl (PAR) standard solution: 0.1% ethanol solution. 3.2.6 2-tetraacetic acid solution: 0.005M (see Appendix A.8): 3.2.7 EDTA (GB1401-78) standard solution: 0.01M (see Appendix A.2) 3.3 Determination procedures
Ministry of Chemical Industry of the People's Republic of China 1984-09-04 1985-10-01 implementation
HG 1—1546-84
Accurately pipette 20 ml of the sample solution prepared in Chapter 2 of this standard, place it in a 250 liter conical flask, add 1+1 ammonia solution until a precipitate is just formed, add 3 ml of glacial acetic acid to dissolve the precipitate, add 4 ml of 10% hydroxylamine hydrochloride solution, let stand for 3 minutes, add 10 ml of 20% ammonium fluoride solution, dilute to about 100 ml, add 6 drops of copper diamine tetraacetate, heat to boiling, add 3 to 5 drops of PAR indicator, and immediately titrate with 0.01M EDTA standard solution. The end point is when the solution changes from red to yellow. 3.4 Calculation
The percentage of nickel oxide (x) is calculated according to formula (1): M·V×74.70
G × 1000
Formula: M--Mer concentration of EDTA standard solution: Volume of EDTA standard solution used for titration, mg--sample weight, g:
74.70--molecular weight of nickel oxide.
3.5 Precision
The relative deviation of two parallel determination results is not more than 2%. 4 Determination of aluminum content
4.1 Summary of the method
Add excess DTA to acetic acid-sodium acetate buffer solution and heat it. Iron, aluminum, titanium and nickel all form complexes. The excess EDTA in the solution is first titrated with copper sulfate standard solution, and then an appropriate amount of sodium fluoride is added to the original complex with aluminum. , titanium complex EDTA replacement, use copper sulfate standard solution to titrate the replaced EDTA, here EDTA is equivalent to the aluminum, subtract the amount of titanium to calculate the aluminum content.
4.2 Reagents
4.2.1 Ethylenediaminetetrasodium (EDTA) (GB1401-78) standard solution: 0.01M (see Appendix A.2). 4.2.2 Acetic acid: sodium acetate buffer solution (pH 4.4): weigh 100g anhydrous sodium acetate (GB694-78), dissolve in water, add 200ml glacial acetic acid (GB676-78), transfer to a 1000ml bottle, dilute to full scale, shake well. 4.2.3 Phenol (HGB3U39-59) indicator: 1% ethanol solution. 4.2.4 Ammonia (GB 631-77): 1 + 1 solution. 4.2.5 Sodium fluoride (GB1264-77): 4% solution: 4 g of sodium fluoride is dissolved in 100 ml of water. After dissolution, let it stand and after the insoluble matter is precipitated, pour the clear liquid into a plastic bottle. 4.2.6 Pyridine-(2-azo-4-yl)pyridine (PAR) indicator: 0.1% ethanol solution, 4.2.7 Copper sulfate (GB665-78) standard solution: 0.01M (see Appendix A.3) 4.8 Determination procedure
Accurately pipette 10 ml of the sample solution prepared in Chapter 2 of this standard, place it in a 250 ml flask, add 10-15 ml of 0.01M EDTA standard solution, add 2 drops of phenolphthalein indicator, neutralize with 1+1 ammonia water until it just turns red, add 5 ml of acetic acid-sodium acetate buffer solution, dilute with water to about 50 ml, boil for 2-3 minutes, add 3-5 drops of PAR indicator, titrate with copper sulfate standard solution, the solution also turns from yellow or green to red or purple (do not count at this time). Add 10 ml of 4% sodium fluoride solution, boil, and titrate with copper sulfate standard solution. The end point is when the liquid changes from green to purple-red. Record the volume of copper sulfate standard solution used in the second titration. 4.4 Calculate the percentage of aluminum oxide (X) according to formula (2): X = MY × 50.98
-x100-Ti02% × 0.6380
G × 1000
Where: M is the molar concentration of copper sulfate standard solution; V
-the volume of copper sulfate standard solution used for titration, milliliters; 2
Tio2%-
the weight of the sample, grams;
the molecular weight of aluminum oxide/2;
the molecular weight of cobalt oxide/2
. The molecular weight of titanium dioxide
the percentage of titanium dioxide.
4.5 Precision
HG1-1546—84
The relative deviation of the results of two parallel determinations is not more than 2%. 5 Determination of calcium content
5.1 Method EDIA volumetric method
5.1.1 Method summary
Use hexamethylenetetramine and copper reagent to precipitate and separate interfering elements such as lead, silver, titanium and nickel. Add triethanolamine to the filtrate to mask the residual iron, aluminum, etc., adjust the pH to about 12 with potassium hydroxide, and use calcium indicator as the indicator to titrate calcium with EDTA standard solution. When the test solution does not contain titanium, add ammonia-ammonium chloride buffer solution, use chrome black T as the indicator, and titrate calcium with EDTA standard solution. However, a small amount of magnesium ethylenediaminetetraacetate needs to be added to obtain a clear end point. 5.1.2 Reagents
5.1.2.1 Octamethylenetetramine (GB1400-78) 5.1.2.2 Sodium diethyldithiocarbamate (copper reagent) (HG3-962-76): 2% solution, freshly prepared. 5.1.2.3 Potassium hydroxide (GB2306-80): 15% solution. 5.1.2.4 Sodium chloride (GB1266-77). 5.1.2.5 Diethanolamine (chemically pure): 1 + 1 solution. Ethylenediaminetetraacetic acid magnesium solution: 0.005M (see Record A, 9). 5.1.2.67 Hydrogen-ammonium chloride buffer solution (pH 10): Weigh 27 grams of ammonium chloride (GB658-77) and place it in a beaker, add 3255.t.2.t
milliliters of water, dissolve it, add 175 liters of ammonia water (GB63177), and shake well. 5.1.2.8 Calcium indicator: 1%, weigh 0.1g calcium indicator and 10g sodium chloride, grind and mix. 5.1.2.9 Indicator: 1%, weigh 0.1g calcium indicator and 10g sodium chloride, grind and mix. 5.1.2.10 Ethylaminetetraacetic acid monosodium (EDTA) (GB1401-78) standard solution: 0.01M (see Appendix A.2). 5.1.3 Determination Procedure
Accurately pipette the sample solution prepared in Chapter 2 of this standard (containing 1-2 mg of calcium oxide), place it in a 250 ml beaker, steam it at low temperature until it reaches nearly zero, blow the beaker wall with a little water, add 2 g of sodium chloride, stir, add 2 g of hexamethylenetetramine, shake well, add 29 liters of 2% copper test solution, stir well, let it stand for 35 minutes, filter it with slow filter paper into a 250 ml conical flask, wash the precipitate with water 5-6 times. Add 4 ml of 1+1-ethanolamine solution to the filtrate, and then add 15 ml of 15% sodium hydroxide solution: add a little calcium indicator, and immediately titrate with EDTA standard solution. The end point is when the solution changes from wine red to blue. When the sample solution does not contain magnesium, add 4 ml of 11-diethanolamine, then add 20 ml of ammonia-ammonium chloride buffer solution, add 2 ml of ethylamine tetraacetic acid magnesium solution, add a little chrome black T indicator, and immediately titrate with EDTA standard solution. The end point is when the solution changes from red to blue.
5.1. 4 Calculate the percentage of calcium oxide (calcium oxide) according to formula (3): X.
Formula M—
MV × 56.08
G×1000
-the molar concentration of EDTA standard solution,
the volume of EDTA standard solution used for titration, the amount of calcium oxide in ml:
take sample by the amount, grams.
5.1.5 Precision
HG1-1546-84
The relative deviation of the results of two parallel determinations shall not exceed 2%. 5.2 Method II Atomic Absorption Method
5.2.1 Method Summary
The sample is dissolved in mixed acid, and the interference of aluminum is eliminated by strontium. The air-acetylene flame atomic absorption spectrometry is used for determination, and the standard curve method is used for quantification. 5.2.2 Reagents
5.2.2.1 Hydrochloric acid (GB 622-.77) (superior grade). 5.2.2.2 Hydrochloric acid (GB622-77) (superior grade): 1+1 solution. 5.2.2.3 Nitric acid (GB 626-78) (superior grade). 5.2.2.4 Strontium nitrate solution: 5 mg/ml, weigh 2.50 g of spectrally pure strontium nitrate, place in a beaker, add water to dissolve, transfer to a 500 ml volumetric flask, dilute to scale, and shake. 5.2.2.5 Oxidation solution: 1 mg/ml, weigh 0.25 g of spectrally pure lanthanum oxide, place in a beaker, add 10 ml of hydrochloric acid, heat to dissolve, transfer to a 250 ml volumetric flask, dilute to scale, shake well, 5.2.2.6 Calcium oxide standard solution: 1 mg/ml, accurately weigh 1.7848 g of calcium carbonate dried at 110℃ for 2 hours, place in a beaker, add 20 ml of 1+1 acid, after dissolving, transfer to a 1000 ml volumetric flask, dilute to scale, and shake well. 5.2.2.7 Calcium oxide standard solution: 40 μg/ml, accurately pipette 10 ml of calcium oxide standard solution, place in a 250 ml volumetric flask, dilute to scale, and shake well.
5.2.3 Instruments
5.2.3.1 Atomic absorption spectrophotometer,
5.2.3.2 Calcium hollow pole lamp,
5.2.4 Determination procedures
5.2.4.1 Drawing of standard curve
Accurately pipette 0.00, 1.00, 2.00, 3.00, and 4.00 ml of calcium oxide working solution into five 100 ml volumetric flasks, respectively, add 2 ml of 1+1 salt solution, 1 ml of palladium nitrate solution, and 2 ml of thiamin solution, dilute to the scale, and spread evenly. According to the instrument operating conditions, at a wavelength of 4227 angstroms, measure the absorbance on the atomic absorption spectrophotometer with air-acetylene flame. Draw the standard curve with absorbance as the ordinate and calcium oxide (μg/ml) as the abscissa. 5.2.4.2 Determination of calcium content
Accurately weigh 0.1000 g of the sample prepared according to Chapter 1 of this standard, place it in a 250 ml beaker, add 10 ml of hydrochloric acid: heat to boiling, add 5 ml of nitric acid, heat to nearly dry, then add 10 ml of 1+1 hydrochloric acid, heat to nearly ten, add 5 ml of 1.+1 hydrochloric acid, heat to boiling, add 30 ml of water, heat to boiling, filter into a 250 ml volumetric flask, wash the beaker and the residue with hot water 5 to 6 times each, dilute to the scale, and shake well. Pipette 5 liters of this liquid into a 260 ml volumetric flask, add 5 ml of 1+1 hydrochloric acid, 2.5 ml of strontium nitrate solution and 5 ml of oxidizing solution, dilute to scale, shake well, and measure the absorbance with the standard series. 5.2.5 Calculation
Calcium oxide percentage (X2) is calculated according to formula (4): X2-
G × 10
W: 0-Calcium oxide is obtained from the standard volume, μg! G-weight of the sample, g.
5.2.6 Precision
The deviation of the results of two less than two determinations is not more than 2%. 6 Determination of magnesium content
6.1 Method I EDTA volumetric method
6.1.1 Method summary
HG 1-1546-84
Use hexamethylenetetramine and copper reagent to precipitate and separate the disturbing elements such as aluminum, titanium, iron and nickel. Add monoethanolamine to the filtrate to mask the residual iron and lead. Add hydrogen...ammonium chloride buffer solution, use chrome black T as an indicator, and titrate magnesium with EDTA standard solution. 6.1.2 Reagents
(. Sodium monothiocarbamate (copper reagent) (HG3-962-76): 2% solution, freshly prepared. 6.1.2.2 Hexamethylenetetramine (GB1400--78). 6.1.2.8 Triethanolamine (chemically pure): 1+1 solution. 6.1.2.4 Sodium chloride (GB1266-77). 6.1.2.5 Ammonia-ammonium chloride buffer solution (pH 10): weigh 27 grams of ammonium chloride (GB658-77) and add 325 ml of water to 11% of the alkali ring. After dissolving, add 175 ml of ammonia water (GB631-77) and shake the spoon. 6.1.2.6 Chrome black T (HGB3086-59) indicator: 1%, weigh 0.1 grams of Chrome black T and 10 grams of sodium chloride, grind and mix. 6.1.2.7 Ethylene Sodium diaminetetraacetate (EDTA) (GB1401-78) standard solution: 0.01M (see Appendix A.2). 6.1.3 Determination procedure
Accurately pipette the sample solution prepared according to Section 2 of this standard (containing about 1-2 mg of magnesium oxide) into a 250 ml beaker. Evaporate at low temperature until nearly dry, purge the beaker with a little water, add 2 g of sodium chloride, stir well, add 2 g of hexamethylenetetramine, stir about, add 20 ml of 2% copper reagent solution, stir well, let stand for 35 minutes, filter with slow filter paper into a 250 ml conical flask, and wash the precipitate with water 5-6 times. Add 4 ml of 1+1 diethanolamine to the filtrate, mix well, add 20 ml of ammonia-ammonium chloride buffer solution, and then add a little chrome black T indicator, and immediately titrate with EDTA standard solution. The end point is when the solution changes from red to blue. 6.1.4 Calculate the percentage of magnesium oxide (X) according to formula (5): XE
Where: M——the molar concentration of EDTA standard solution: Mv'x 40.31
G ×1000
The volume of EDTA standard solution used for titration, liters: G
The weight of the sample taken per minute, grams,
The molecular weight of magnesium oxide.
If calcium and magnesium exist in the sample at the same time, this method will determine the total amount of calcium and magnesium. The percentage of magnesium oxide (X") should be calculated according to formula (6) (the sampling volumes of calcium and magnesium should be alternated during the determination): X, =M (Vs-V) ×40.31
G X1000
The volume of EDTA-free standard solution for calcium titration, milliliters; Wuzhong:—
M——the molar concentration of EDTA standard solution; V
The volume of EDTA-free standard solution for calcium and magnesium titration, milliliters! The weight of the sample, grams;
40.31--Molecular weight of magnesium oxide,
6.1.5 Precision
The relative deviation of the results of two parallel determinations is not greater than 1%. 6.2 Method II Atomic Absorption Method
6.2.1 Method Summary
The sample is dissolved in mixed acid, strontium and lanthanum are used to eliminate the interference of lead, and the air-acetone fast flame atomic absorption spectrometry is used for determination, and the standard curve method is used for quantification.
6.2.2 Reagents
6.2.2.1 Hydrochloric acid (GB622-77) (superior grade). 6.2.2.2 Hydrochloric acid (GB622-77) (superior grade): 1+1 solution, 6.2.2.3 Nitric acid (GB626-78) (superior grade). HG 1—1546—84
6.2.2.4 Strontium nitrate solution: 5 mg/ml, weigh 2.5 g of spectrally pure strontium nitrate, dissolve in water, transfer to a 500 ml volumetric flask, dilute to scale, and shake.
6.2.2.5 Iron oxide solution: 1 mg/ml, weigh 0.25 g of spectrally pure lanthanum oxide, place in a beaker, add 10 ml of hydrochloric acid, heat to dissolve, transfer to a 250 ml volumetric flask, dilute to scale, and mix well. 6.2.2.6 Magnesium oxide standard solution: 1 mg/ml, accurately weigh 1.0000 g of high-purity magnesium oxide calcined at 850℃ for 1 hour, place in a beaker, add 20 ml of 1+1 hydrochloric acid, dissolve, transfer to a 1000 ml volumetric flask, dilute to scale, and shake well. 6.2.2.7 Magnesium oxide working solution: 40 μg/mL. Accurately pipette 10 ml of magnesium oxide standard solution, place it in a 250 ml volumetric flask, dilute to the mark, and shake well.
6.2.8 Instruments
6.2.3.1 Atomic absorption spectrophotometer:
6.2.3.2 Magnesium hollow cathode lamp.
6.2.4 Determination procedures
6.2.4.1 Drawing of standard curve
Accurately pipette 0.00, 1.00, 2.00, 3.00, and 4.00 ml of magnesium oxide working solution, place them in 15 100 ml volumetric flasks, add 2 ml of 1+1 hydrochloric acid, 1 ml of strontium nitrate solution, and 2 ml of argon oxide solution, dilute to the mark, and shake well. According to the working conditions of the instrument, use air-acetylene flame at a wavelength of 2852 angstroms. Measure the absorbance on an atomic absorption spectrophotometer. Use the absorbance as the vertical mark and the amount of magnesium oxide (μg/ml) as the horizontal mark to draw a standard curve. 6.2.4.2 Determination of magnesium content
Accurately weigh 0.1000 g of the sample prepared according to Section 1 of this standard, place it in a 250 ml beaker, add 10 ml of hydrochloric acid, heat to boiling, add 5 ml of nitric acid, heat to nearly dry, add 10 ml of 1+1 hydrochloric acid, heat to nearly F, add 5 ml of 1+1 hydrochloric acid, heat to boiling, add 30 ml of water, heat to boiling, filter into a 250 ml volumetric flask, wash the beaker and residue with hot water 5 to 6 times each, dilute to the scale, and shake well. Take 5 ml of this solution and place it in a 250 ml volumetric flask 1, add 5 ml of 1+1 hydrochloric acid, 2.5 ml of strontium nitrate solution and 5 ml of oxidation solution to dilute to full scale, shake about, and measure the absorbance together with the standard series. 6.2.5 Calculation
The amount of magnesium oxide (X2) is calculated according to the formula (?): X2=
Q × 250
G x 10\
Wherein: Q is the amount of magnesium oxide obtained from the standard sweet line, microgram G
is the weight of the sample, gram.
6.2.6 Precision
The relative deviation of the results of two determinations is not more than 2%. 7 Determination of iron content
7.1 Summary of the method
Use hydroxylamine hydrochloride to reduce monovalent iron to divalent iron. In a solution with a pH of -2 to 6, divalent iron and o-phenanthroline form a stable red complex, which is determined by spectrophotometry.
7.2 Reagents
7.2.1 Hydrochloric acid (GB622--77) : 112 solution. 7.2.2 Hydroxylamine hydrochloride (HG3-967-76): 10% solution. 7.2.3 O-phenanthene (GB1293-77): 0.25% solution, weigh 1.63 g of o-phenanthene, add 10 ml of anhydrous ethanol, dissolve, transfer to a 250 ml volumetric flask, dilute to the mark, and stir. 7.2.4 Acetic acid-sodium acetate buffer solution (pH 4.4): weigh 100 g of sodium acetate (GB694-65), dissolve in water, add 200 ml of glacial acetic acid (GB676-78), transfer to a 1000 ml volumetric flask, dilute to the mark, and shake. HG 1—1546—84
7.2.5 Ferric oxide standard solution: 0.2 mg/ml, accurately weigh 0.1399 g of pure iron wire (content above 99.9%), place in a beaker, add 25 ml of 1+2 hydrochloric acid, slightly heat to dissolve, transfer to a 1000 ml volumetric flask, dilute to scale, and shake well. 7.2.6 Ferric oxide working solution: 0.02 mg/ml, accurately pipette 25 ml of ferric oxide standard solution, place in a 250 ml volumetric flask, dilute to scale, and shake well. 7.3 Instrument
Spectrophotometer.
7.4 Determination procedure
7.4.1 Drawing of standard curve
Accurately pipette 0.00, 1.00, 2.00, 3.00, 4.00, 5.00, and 6.00 ml of ferric oxide working solution, place in In 7 100 ml volumetric flasks, add 2 ml of 10% hydroxylamine hydrochloride solution, shake, let stand for 3 minutes, add 15 ml of acetic acid-sodium acetate buffer solution, add 5 ml of 0.25% o-phenanthroline solution, dilute to scale, shake, let stand for 5 minutes. In a spectrophotometer, use the reagent as a reference and measure the absorbance at a wavelength of 510 nm with a 3 cm colorimetric tube. Draw a standard curve with absorbance as the ordinate and ferric oxide (mg/.100 ml) as the abscissa. 7.4.2 Determination of iron content
Accurately pipette 5 ml of the sample solution prepared in Chapter 2 of this standard, place it in a 100 ml volumetric flask, add 2 ml of 10% hydroxylamine hydrochloride solution, shake, let stand for 3 minutes, add 15 ml of acetic acid-sodium acetate buffer solution, add 5 ml of 0.25% o-phenanthroline solution, dilute to scale, shake, let stand for 5 minutes. On a spectrophotometer, with the reagent as reference, the absorbance is measured at a wavelength of 510 nanometers using a 3 cm colorimetric blood.
7.5 Calculation
The percentage of ferric oxide (X) is calculated according to formula (8): =
GxJ000
Where: - the amount of ferric oxide obtained from the standard curve, mg; G—the amount of sample taken, g.
7.6 Precision
The relative deviation of the results of two parallel determinations is not greater than 2%. 8: Determination of titanium content
8.1 Summary of the methodwwW.bzxz.Net
In a strong acid solution, titanium ions and hydrogen peroxide form a stable yellow complex, which is determined by spectrophotometry. Nickel and iron have interference, which can be eliminated by using the test solution as a reference.
8.2 Reagents
8.2.1 Sulfuric acid (GB625-77): 1+2 solution. 8.2.2 Hydrogen peroxide (GB1616-79): 1+ 9 solution. 8.2.3 Titanium dioxide standard solution: 0.2 mg/ml (see Appendix A.4). 8.3 Instruments
Spectrophotometer.
8.4 Determination procedures
8.4.1 Drawing of standard curve
Accurately pipette 0.0, 1.00, 2.00, 3.00, 4.00, 5.00, 6.00 liters of titanium monoxide standard solution, place them in 7 50 ml volumetric flasks, add 7 ml of 1+2 sulfuric acid and 15 ml of 1+ hydrogen peroxide, dilute to the scale, and shake well. In the spectrophotometer!, with the reagent as the reference, at a wavelength of 410 nm, and a 3 cm colorimetric muscle, measure the absorbance. Draw the standard curve with absorbance as the ordinate and the amount of titanium oxide (mg/50 ml) as the abscissa. : 8.4.2 Determination of titanium content
HG1-1546--84
Accurately pipette 20 liters of the sample solution prepared in Chapter 2 of this standard into a 50 ml volumetric flask, add 7 ml of 1+2 sulfuric acid and 15 ml of 1+9 hydrogen peroxide, dilute to the mark, and set aside. On a spectrophotometer, take the test solution as a reference (the reference test solution does not contain hydrogen peroxide), and measure the absorbance at a wavelength of 410 nm using a 3 cm colorimetric III. : 8.5 Calculation
The percentage of titanium dioxide (X) is calculated according to formula (9): X
G×1000
Where: α is the amount of titanium dioxide obtained from the standard curve, mg; G is the weight of the sample, g,
8.6 Precision
The relative deviation of the results of two parallel determinations is not less than 4%. 9 Determination of silicon content
9.1 Method I Gravimetric method
9.1.1 Method Summary
After melting the sample with sodium carbonate, decompose the olefin with hydrochloric acid, evaporate to a wet state, add hydrochloric acid, keep the solution at a certain acidity, and at a temperature of 70-80℃, condense silicic acid with gelatin to precipitate H. After burning, treat with hydrofluoric acid and determine the silicon dioxide by gravimetric method. 9.1.2 Reagents
9.1.2.1 Anhydrous sodium carbonate (GB639-77). 8.1.2.2 Gelatin (chemically pure): 1% solution, freshly prepared. 9.1.2.3 Hydrochloric acid (GB622-77): 1+1 solution. 9.1.2.4 Sulfuric acid (GB625-77): 1+1 solution. 9.1.2.5 Hydrofluoric acid (GB621--77)
9.1.2.6 Hydrochloric acid (GB 622-77).
9.t.3 Apparatus
Pressure: 30~50 μl:
9.1.4 Determination procedure
Accurately weigh 0.5000 g of the sample prepared according to Section 1 of this standard, place it in a platinum crucible containing 6 g of sodium carbonate, scoop it with a fine-headed glass rod, wipe the glass rod with a small piece of fixed paper, put the filter paper into the crucible, cover it with 2 g of sodium carbonate, cover the crucible with a lid, and place it in a high-temperature furnace, raise the temperature from room temperature to 950°C, and melt it for 1 hour. Take out and cool, put the crucible into a 250 ml II beaker, add 30-40 ml of 11 hydrochloric acid, heat until all the frits are leached, wash the glass and lid with water, put the beaker on a water bath, evaporate the solution until it is moist, then add 15 ml of acid, stir evenly, heat to a slight boil for 1 minute, when the temperature of the solution is 70-80°C, add 10 liters of 1% animal glue solution, stir well, and keep warm for 10 minutes. Dilute with hot water to 40-50 ml, stir, filter with medium-speed quantitative filter paper, wipe the beaker, wash the precipitate with 1-49 hot salt for 5 times, collect the filtrate and washing liquid in a 250 ml volumetric flask, and then wash with water until there is no chloride ion. Put the precipitate in a crucible and ash it at low temperature, and burn it in a high temperature furnace at 950℃ to constant weight. Then add 4-5 drops of 1+1 sulfuric acid and 10-15 ml of hydrochloric acid, place it in a sand bath and evaporate it, remove all the trisulfur, and then put it in a high temperature furnace and burn it at 1950℃ to constant weight. 9.1.5 Calculate the oxidation residue (X,) according to formula (10): X=
Where: A-weight of precipitate before chlorofluoric acid treatment, g; B-weight of residue in crucible after hydrofluoric acid treatment, g; G-weighed sample, g.
, 9.1.6 Precision
x 100--
HG 1—1546—84
The relative difference between the results of two parallel determinations shall not be less than 1%. 9.2 Method II Potassium fluorosilicate volumetric method
9.2.1 Summary of the method
The sample is melted with alkali to convert the insoluble silicate into soluble silicate, which is then leached with hot water. In the presence of potassium chloride and potassium fluoride, the soluble silicate quantitatively generates potassium fluorosilicate precipitate in an acidic solution. The precipitate is hydrolyzed into hydrofluoric acid in boiling water and titrated with sodium hydroxide standard solution. 9.2.2 Reagents
9.2.2.1 Hydrochloride (GB2306---80) (superior purity). 9.2.2.2 Nitric acid (GB 626—78).
Potassium chloride (GB 9.2.2.43
Potassium chloride (GB646-77): 5% solution (use phenolic acid as indicator and change color). 9.2.2.44
Potassium chloride (GB646-77): 5% ethanol solution. Weigh 5 g potassium chloride and dissolve it in 50 ml water. Add 509.2.2.5
ml ethanol and mix well. Use phenol as indicator and neutralize with 0.1N sodium hydroxide solution. . Fluoride (GB1271-77): 15% solution. 9.2.2.6
Phenol (HGB3039--59) indicator: 1% alcohol solution 9.2.2.7
Sodium hydroxide (GB629--77): 2% solution. 9.2.2.9 Hydrogen simplification (GB629--77) standard solution: 0.1N (see Appendix A, 5), 9.2.3 Instrument ||t 9.2.3.1 Silver slurry: 30-50 ml, plastic cup: 300 ml; plastic cup: 25 ml, plastic funnel: 70 mm, 9.2.4 Determination procedure Weigh 1 gram of potassium hydroxide and put it in a silver crucible, heat it to melt, and after cooling, accurately weigh 0.2000 grams of the sample prepared in Chapter 1 of this standard, put it in a silver glass, cover it with 1 gram of potassium hydroxide, put the silver glass in a high-temperature furnace, heat it to 500℃, take it out after 10 minutes, cool it slightly, use hot water to melt the slurry and wash the floating silver glass and cover, and put the overflow and washing liquid in 300 mm plastic cup. Add 10 liters of nitric acid (the volume should not exceed 40 ml at this time). Cover it with a lid, shake it, cool it quickly to room temperature, add 2-3 minutes of potassium chloride, stir and crush the dissolved potassium chloride particles. Add 10 ml of 15% potassium fluoride solution, let it stand for 10 minutes, filter with fast filter paper and plastic funnel, wash the cup and precipitate with 5% potassium chloride aqueous solution 3 to 4 times (about 5 ml each time), put the filter paper together with the precipitate into the original plastic cup, add 10 ml of 5% potassium chloride ethanol solution along the cup, add 10 parts acid indicator, first use 2% sodium hydroxide, then use 0.1N sodium chloride to neutralize until red (stir while dripping back, wipe the cup and crush the filter paper during neutralization), quickly add about 200 ml of boiling water neutralized with dilute hydrochloric acid and 2 ml of the indicator, and immediately titrate with 0.1N sodium hydroxide standard solution. The end point is when the solution changes from colorless to slightly red. 9.2.5 Calculation
Silicon dioxide percentage (X:) is calculated according to formula (11): X.
wherein N
NV × 0.01502
Normal concentration of sodium hydrocyanide standard solution; Volume of sodium deoxygenated oxide standard solution for titration, liter: 0.01502...Nanogram equivalent of silicon dioxide; G -
Weighing sample weight, gram.
9.2.6 Precision
The relative deviation of the two determination results shall not be less than 2%. 9.3 Method III Silicate-molybdenum blue colorimetric method
9.3.1 Method summary
HG 1-1546-84
After the sample is dissolved, in an acidic solution, silicic acid reacts with ammonium pyrophosphate to form yellow silicon complex ions, which are reduced to silicon complex ions by ammonium ferrous sulfate in the presence of oxalic acid and determined by spectrophotometry. 9.3,2 Reagents
9.3.2.1 Sulfuric acid (GB625-77) 1+2 solution. 9.3.2.2 Sulfuric acid (GB625--77) 1+35 solution. 9.3.2.3 Oxalic acid (HG3-988-76): 5% solution. 9.3.2.4 Ammonium ferrous sulfate (GB661-77): 6% solution. Add 2 ml of 1+2 sulfuric acid to 98 ml of water, and then add 6 g of ammonium ferrous sulfate.
9.3.2.5 Ammonium molybdate (GB657-79): 5% solution, freshly prepared. 9.3.2.6 Silicon dioxide as working solution: 0.05 mg/mL (see Appendix A.7) 9.3.2.7 Sodium hydroxide (GB629-77): 8% solution. 9.3.2.8 Phenol (HGB3039-59) indicator: 1% ethanol solution. 9.3.3 Instruments
Spectrophotometer.
9.3.4 Determination procedures
9.3.4.1 Drawing of standard band lines
Accurately pipette 0.00, 1.00, 2.00, 4.00, 6.00, 8.00, 10.00 ml of silica working solution into 7 100 ml bottles respectively, add 25 mM water, 1 drop of phenol indicator (the solution is red at this time), drop 1+35 sulfuric acid to make it fade, then add 10 ml of 1+35 sulfuric acid and 5 ml of 5% molybdic acid solution, hook, and leave for 10 minutes. Add 10 liters of 5% oxalic acid solution, 15 ml of 1+2 sulfuric acid and 10 ml of 6% ammonium ferrous sulfate solution, dilute to the scale, and rub. On the spectrophotometer, use the reagent as a reference and measure the absorbance at 700 nm with a 1 cm colorimetric meter. Draw a standard curve with absorbance as the ordinate and silicon chloride content (mg/100 ml) as the abscissa.
9.3.4.2 Determination of silicon content
Accurately pipette 10 mg of the sample solution prepared according to Section 2 of this standard into a 100 ml volumetric flask, add 25 ml of water, 1 drop of phenolphthalein indicator, add 8% sodium hydroxide solution until it turns slightly red, add 10 ml of 1+35 sulfuric acid and 5 ml of 5% molybdic acid solution, shake well, and leave for 10 minutes. Add 10 ml of 5% oxalic acid solution, 15 ml of 12% sulfuric acid and 10 ml of 6% ammonium ferrous sulfate solution, dilute to the scale, and shake well. On a spectrophotometer, use the reagent as a reference and measure the absorbance at a wavelength of 700 nm using a 1 cm colorimetric plate. 9.3.5 Calculation
The percentage of silicon monoxide (X,) is calculated according to formula (12): x,
G x 100
Wherein: Q—the amount of silicon dioxide obtained from the standard curve, mg! G—the weight of the sample, g.
9.3.6 Precision
The root mean square deviation of the results of two parallel determinations is not more than 4%. 10 Determination of potassium content
10.1 Summary of the method
The sample is treated with hydrofluoric acid and sulfuric acid and then determined by flame photometry. 10.2 Reagents
10.2.1 Hydrofluoric acid (GB620-77)
10.2.2 Sulfuric acid (GB625-77): 1+1 solution. 10.2.3 Potassium oxide standard solution: 2 mg/ml. Accurately weigh 2.1467 g potassium nitrate (GB647-77) (superior purity) dried at 110°C for 2 hours, dissolve it in a small amount of water, transfer it to a 500 ml volumetric flask F, and dilute to the mark.
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