Some standard content:
Record number: 2773-1999
HG/T 3587-1999
This standard is formulated in accordance with relevant enterprise standards, and is divided into three levels according to the actual situation of domestic product production and product quality, with ten indicators.
The main difference between this standard and the enterprise standard is that the indicators are increased from seven to ten, and the corresponding analysis methods are formulated. This standard was proposed by the Technical Supervision Department of the former Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the inorganic salt product standardization technical unit of the Ministry of Chemical Industry. The drafting units of this standard are: Tianjin Chemical Research Institute of the Ministry of Chemical Industry, Hebei Xinji Chemical Plant, and Xingtai Iron and Steel Company Nonferrous Metal Smelting Plant. The main drafters of this standard are: Liu Youruo, Guo Fengxin, Zhao Hui, Tian Lingzhi, and Zhang Yinhuan. This standard is entrusted to the inorganic salt product standardization technical unit of the Ministry of Chemical Industry for interpretation. 1085
1 Scope
Chemical Industry Standard of the People's Republic of China
High purity barium titanate for electronic industrial use
High purity barium titanate for electronic industrial useHG/T 3587--1999
This standard specifies the requirements, sampling, test methods, marking, packaging, transportation and storage of high purity barium titanate for electronic industrial use. This standard applies to high purity barium titanate for electronic industrial use, which is mainly used in the electronic industry as a material for manufacturing nonlinear components, dielectric amplifiers, memory components of electronic computers, micro capacitors and ultrasonic generators. Molecular formula: BaTiO
Relative molecular mass: 233.20 (according to the international relative atomic mass in 1995)2
Cited standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. Packaging, storage and transportation pictorial marking
GB 191--1990
GB/T 602--1988
GB/T 603-1988
Preparation of standard solutions for determination of impurities in chemical reagents (neqISO6353-1:1982) Preparation of preparations and products used in test methods for chemical reagents (neqISO6353-1:1982) GB/T 1250—1989
Methods for expressing and determining limit values GB/T3049--1986
O-phenanthroline spectrophotometry (negISO6685: General method for determination of iron content in chemical products 1982)
GB/T 6678—1986
General rules for sampling of chemical products
GB/T 6682---1992
GB/T 8946-1988
3 Requirements
3.1 Appearance: white powder.
Specifications and test methods for water used in analytical laboratories (eqvISO3696:1987) Plastic woven bags
3.2 High-purity barium titanate for electronic industry shall meet the requirements of Table 1. Table 1 Requirements
BaO2/TiO2 Ratio (BaO2/TiO2)Barium titanate (BaTiO2) content/%
Strontium oxide (SrO2) content/%
Sodium oxide (Naz0) content/%
Potassium oxide (K0) content/%
Aluminum oxide (Al0) content7%
Silicon oxide (Si22) content/%
Iron oxide (Fe02) content/%
Magnesium oxide (Mg02) content g()）content/%
Average particle size/um
Approved by the State Administration of Petroleum and Chemical Industry on April 20, 19991086
Superior product
1.000±0.003
First-class product
Qualified product
1.000±0.005
1.000±0.010
Implemented on April 1, 2000
4 Test method
HG/T 3587—1999
The reagents and water used in this standard refer to analytical pure reagents and grade 3 water specified in GB/T6682 unless otherwise specified. The standard titration solution, impurity standard solution, preparation and products used in the test, unless otherwise specified, are prepared in accordance with the provisions of GB/T601, GB/T602 and GB/T603.
Safety Tips: When using strong acid and strong alkali in the analysis process of this standard, caution must be exercised; when heating and dissolving samples, the process must be carried out in a fume hood. 4.1 Determination of barium titanate content
4.1.1 Method Summary
In a strong acidic medium, slowly heat the sample to transform its crystal form, then add water to dissolve it, then use EDTA to mask titanium, use ammonium sulfate as a precipitant, and produce barium sulfate precipitation with barium ions. 4.1.2 Reagents and materials
4.1.2.1 Hydrochloric acid;
4.1.2.2 Ammonia solution: 1+1;
4.1.2.3 Silver nitrate solution: 10g/L;
4.1.2.4 Ammonium sulfate solution: 250g/L;
4.1.2.5 Ammonia solution of disodium ethylenediaminetetraacetate: weigh 38g disodium ethylenediaminetetraacetate and dissolve it in 1000mL 1+5 ammonia solution;4.1.2.6 Methyl orange indicator solution: 1g/L.
4.1.3 Analysis steps
Weigh about 0.5g of sample (accurate to 0.0002g), place it in a 200mL beaker, add a small amount of water to wet the sample, and shake it. Add 15ml hydrochloric acid, place it above the electric furnace about 5cm away from the electric furnace and heat it slowly, shaking it while heating. After the crystal form is transformed (that is, the solution changes from colorless to light yellow and then to colorless, and the sample becomes loose particles), add 15ml water at this time and continue heating until the sample is completely dissolved. Filter with slow qualitative filter paper, wash the insoluble matter with hot water until the filtrate is free of chloride ions (test with silver nitrate solution), and collect the filtrate and washing liquid in a 400ml beaker. Add 50ml ammonia solution of disodium ethylenediaminetetraacetic acid, adjust the solution volume to 300ml, add 1 drop of methyl orange indicator solution, add ammonia water to adjust the solution to yellow, heat to boiling, and add 20ml ammonium sulfate solution while stirring continuously. Move to a water bath to keep warm and precipitate for more than 2h. Filter with slow quantitative filter paper, wash the precipitate with hot water until there is no chloride ion (test with silver nitrate solution). Place the precipitate together with the filter paper in a porcelain crucible that has been dried to constant weight at 800℃～~850℃, incinerate at low temperature, then burn at 800℃～850℃ for 40min, cool in a dryer, weigh, and burn again until constant weight. 4.1.4 Expression of analysis results
The titanate content (BaTiO:)X expressed as mass fraction is calculated according to formula (1): (ml= mo)× 0.999 2×100 (ml mo)×99.92Xi
Where: ml—mass of precipitate and crucible, g; mass of crucible, g;
m——mass of sample, g;
0.9992barium sulfate conversion coefficient to barium titanate. 4.1.5 Allowable difference
Take the arithmetic mean of the parallel determination results as the determination result. The absolute difference of the parallel determination results shall not exceed 0.3%. 4.2 Molar ratio of barium oxide to titanium dioxide
4.2.1 Determination of titanium dioxide content
4.2.1.1 Summary of method
....( 1)
Dissolve the sample with sulfuric acid and ammonium sulfate, add water and hydrochloric acid, and then add metallic aluminum to reduce titanium dioxide. After cooling, titrate with ammonium thiocyanate solution as an indicator and ammonium ferric sulfate standard titration solution. 4.2.1.2 Reagents and materials
4.2.1.2.1 Sulfuric acid.
4.2.1.2.2 Hydrochloric acid.
4.2.1.2.3 Metallic aluminum.
4.2.1.2.4 Ammonium sulfate.
4.2.1.2.5 Saturated sodium bicarbonate solution.
4.2.1.2.6 Saturated potassium thiocyanate solution.
HG/T 3587-—1999
4.2.1.2.7 Standard titration solution of ammonium ferric sulfate: c［NH,Fe（SO4) about 0.1mol/L. Preparation: weigh 49g ammonium ferric sulfate［NH.Fe（SO4)2·12H,O is dissolved in 300mL hydrochloric acid aqueous solution (including 10mL 1→1 hydrochloric acid solution), then transferred to a 1000mL volumetric flask, diluted to the mark with water, and shaken. Calibration: Take 25mL of the above solution, place it in a 250mL iodine volumetric flask, add 35mL water, 3g potassium iodide, and then add 3mL 1+1 hydrochloric acid solution, immediately cover the stopper and gently shake well, and place it in a dark place for 10min. Take it out and rinse the stopper and bottle wall with water, titrate with sodium thiosulfate standard titration solution until the solution turns light yellow, add 10mL sodium acetate solution (250g/L), add 1mL starch solution, and continue titrating until the blue disappears. And perform a blank test.
The actual concentration of the standard titration solution of ammonium ferric sulfate in mol/L is calculated according to formula (2): -(Vi-Vo)c2
Wu Zhong: (-—
The actual concentration of the standard titration solution of ammonium ferric sulfate, mol/L; V.…-The volume of the standard titration solution of sodium thiosulfate consumed by the titration test solution, mL; Vo—-The volume of the standard titration solution of sodium thiosulfate consumed by the titration blank test solution, mL; -The actual concentration of the standard titration solution of sodium thiosulfate, mol/L. 4.2.1.3 Instruments and equipment
Glass liquid sealed tube (see Figure 1): 250mL. 1—Glass liquid sealed tube; 2-Rubber stopper; 3-Triangular pyramidal flask Figure 1||t t||4.2.1.4 Analysis steps
（2）
Weigh 0.4g of sample (accurate to 0.0002g), place it in a 500mL conical flask, add a small amount of water to rinse the flask wall, shake it to form an emulsion, add 20mL of sulfuric acid and 10g of ammonium sulfate. Place it on an electric furnace, heat it slowly at first, and finally heat it to dissolve. After cooling, add 80ml of water and 20ml of hydrochloric acid, shake it thoroughly, add 2.5g of metal aluminum, install the liquid seal tube as shown in Figure 1, and plug the rubber stopper tightly. The liquid seal tube is pre-added with a saturated sodium bicarbonate solution to about 2/3 of the tube volume. When the metal aluminum is completely dissolved and the solution is purple, cool it to room temperature. Remove the liquid seal tube. Pour the saturated sodium bicarbonate solution into the conical flask and rinse the rubber stopper and the flask wall with a small amount of water. Add 3mL of saturated potassium thiocyanate solution and immediately titrate with standard ammonium ferric sulfate solution until the solution turns light brown for about 30 seconds. This is the end point. Simultaneously perform a vacuum test.
Note: 1) At this time, the sodium bicarbonate solution refluxes into the conical flask, and the reflux stops after carbon dioxide is produced. 4.2.1.5 Expression of analysis results
The titanium dioxide content X2 expressed as mass fraction is calculated according to formula (3): X = c(Vi-V.)×0. 079 88 × 100 = c(Vl-Vo)×7. 88m
Where:
0. 079 88-
actual concentration of ammonium ferric sulfate standard titration solution, mol/L; m
volume of ammonium ferric sulfate standard titration solution consumed by titrating the test solution, mL; volume of ammonium ferric sulfate standard titration solution consumed by titrating the blank test solution, mL; mass of the sample, g;
(3)
the equivalent of 1.00mL of ammonium ferric sulfate standard titration solution [c(NH,Fe（SO4)2=1.000mol/L] The mass of titanium dioxide expressed in grams.
4.2.1.6 Allowable difference
The arithmetic mean of the results of two parallel determinations is taken as the determination result. The absolute difference of the parallel determination results shall not exceed 0.1%. 4.2.2 Expression of the molar ratio of barium oxide to titanium dioxide The molar ratio of barium oxide to titanium dioxide (BaO/TiO2) is calculated according to formula (4): BaO/TiO2
X/233.20.3425X
X/79. 88
Wherein: X.…-the percentage of titanic acid determined according to 4.1, %; X--the percentage of titanium dioxide determined according to 4.2.1, %; 233.2---the relative molecular mass of barium titanate; 79.88…the relative molecular mass of titanium dioxide. 4.3 Determination of strontium oxide content
4.3.1 Summary of method
The sample is slowly heated in a strong acid medium, and after its crystal transformation, it is dissolved in water. At a wavelength of 460.7nm, the strontium content is determined by the standard addition method using an air-acetylene flame.
4.3.2 Reagents and materials
4.3.2.1 Hydrochloric acid;
4.3.2.2 Potassium chloride solution: 10g/L;
4.3.2.3 Strontium standard solution: 1mL of solution contains 0.05mgSr. Use a transfer Take 50ml of the strontium standard solution prepared according to GB/T602 with a liquid pipe, place it in a 100mL volumetric flask, dilute it with water to the mark, and shake it.
4.3.3 Instruments and equipment
Atomic absorption spectrophotometer: equipped with a strontium hollow cathode lamp. 4.3.4 Determination steps
4.3.4.1 Preparation of test solution A
Weigh 1g of the sample (accurate to 0.01g), add 30mL of hydrochloric acid to a 200mL beaker. Place it on an electric furnace and heat it slowly. After its crystal form is transformed (that is, the solution changes from colorless to light yellow and then to colorless, and the sample becomes loose particles.), add 30mL of water and continue to heat and dissolve. Remove it, cool it, transfer it to a 100mL volumetric flask, dilute it with water to the mark, and shake it; filter it with a dry filter, discard 10mL of the initial filtrate, and collect the filtrate in a polyethylene plastic bottle. This solution is test solution A. This solution is reserved for the determination of sodium oxide, potassium oxide and iron oxide content.
4.3.4.2 Preparation of blank test solution
HG/T 3587--1999
Except for not adding the sample, the amount of other reagents added is exactly the same as that of the test solution, and is treated in the same way as the sample. 4.3.4.3 Determination
In four 50ml volumetric flasks, add 20.00ml of superior product, 5.00ml of first-class product and qualified product test solution A (4.3.4.1), and then add 0.00ml, 1.00ml, 2.00ml, 3.00ml of strontium standard solution respectively, and add 2ml of potassium chloride solution respectively, dilute to the scale with water, and shake. On the atomic absorption spectrophotometer, adjust to zero with the blank test solution and determine the absorbance of each solution. Draw a curve with the content of strontium standard solution as the horizontal axis and the corresponding absorbance as the vertical axis. Extend the curve in the opposite direction and intersect with the horizontal axis. The intersection point is the content of strontium element to be measured.
4.3.5 Expression of analysis results
Content X of strontium oxide (SrO) expressed as mass fraction: Calculate according to formula (5): X
mi X 1. 183
m×100
X100 = 11.83 ml
The mass of strontium in the test solution obtained by the graphical epitaxy method, mg; Wu: mi
m-mass of the sample, g;
V——volume of the test solution A added, mL, coefficient for converting strontium to strontium oxide.
4.3.6 Allowable difference
Take the arithmetic mean of the results of two parallel determinations as the determination result. The absolute difference of parallel determination results: the superior product is not more than 0.002%, the standard product and qualified product is not more than 0.05%. 4.4 Determination of sodium oxide and potassium oxide content
4.4.1 Summary of method
After the sample is dissolved, the standard addition method is used on a flame photometer or an atomic absorption spectrophotometer with flame emission to measure the spectral intensity of sodium and potassium excited by flame combustion at wavelengths of 589.0nm and 766.5nm, respectively, to calculate the sodium oxide and potassium oxide content.
4.4.2 Reagents and materials
4.4.2.1 Hydrochloric acid.
4.4.2.2 Sodium standard solution: 1mL of solution contains 0.01mgNa. Use a pipette to transfer 10ml of sodium standard solution prepared according to GB/T602 into a 100mL volumetric flask, dilute with water to the mark, and shake the hook. The solution is stored in a polyethylene plastic bottle. 4.4.2.3 Potassium standard solution: 1 mL of solution contains 0.01 mg K. Use a pipette to transfer 10 mL of potassium standard solution prepared according to GB/T602 into a 100 mL volumetric flask, dilute to the mark with water, and shake well.
4.4.3 Instruments and equipment
Flame photometer or atomic absorption spectrophotometer with flame emission. 4.4.4 Analysis steps
In a set of 100 mL volumetric flasks, add 20.00 mL of superior product, 10.00 mL of first-class product, and 2.00 mL of qualified product test solution A (4.3.4.1), and then add 0.00 mL, 1.00 mL, 2.00 mL, 3.00mL sodium and potassium standard solutions, dilute to the mark with water, and shake to hook.
Use a flame photometer or an atomic absorption spectrophotometer with flame emission, adjust the wavelength to 589.0nm for sodium and 766.5nm for potassium with the blank test solution (4.3.4.2) to zero, and measure the radiation intensity of sodium and potassium. Draw a curve with the content of the added standard solution as the horizontal axis and the corresponding radiation intensity as the vertical axis. The curve is reversed and intersected with the horizontal axis. The intersection is the content of sodium and potassium to be measured. 1090Www.bzxZ.net
Note: 2) When measuring potassium, the recommended slit is 0.4mm. 4.4.5 Expression of analysis results
HG/T 3587—1999
The sodium oxide (Na:O) content X expressed as mass fraction is calculated according to formula (6): X4 =
Wherein: m
ml×1.348
m×jo0
The mass of sodium in the test solution obtained by the graphic extension method, mg; -The mass of the sample in 4.3.4.1, g;
V——--The volume of the test solution A added, mL; 1.348.--The coefficient for converting sodium into sodium oxide. The potassium oxide (K,O) content X expressed as mass fraction. Calculate according to formula (7): m2 X 1.205
m×100
×100=
--the mass of potassium in the test solution obtained by the graphical extension method, mg; where: mi-
m—the mass of the test material in 4.3.4.1, g;
V—the volume of the added test solution A, mL; 1.205-——the coefficient for converting potassium into potassium oxide. 4.4.6 Allowable difference
·(7)
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results is not more than 0.0005% for superior sodium oxide, not more than 0.002% for first-class products, and not more than 0.01% for qualified products; and not more than 0.001% for superior and first-class potassium oxide, and not more than 0.005% for qualified products.
4.5 Determination of aluminum oxide content
4.5.1 Summary of method
Use anhydrous sodium carbonate to melt the sample, leach the melt with water, and then heat it in a boiling water bath to dissolve and filter. At pH 3.8 or so, use aluminum reagent to form a red complex with aluminum in the filtrate. Measure its absorbance at a wavelength of 530 nm. 4.5.2 Reagents and materials
4.5.2.1 Anhydrous sodium carbonate.
4.5.2.2 Ammonia solution: 1+10.
4.5.2.3 Ascorbic acid solution: 10g/L. 4.5.2.4 Sulfuric acid solution: 1+10.
4.5.2.5 Mixed reagent solution.
Weigh 1g aluminum reagent, 20g gum arabic, 267g ammonium acetate, dissolve them in water, mix with 253mL hydrochloric acid, filter, and dilute to 2000mL with water.
4.5.2.6 Aluminum standard solution: 1mL solution contains 0.004mgAl. Use a pipette to transfer 4mL of aluminum standard solution prepared according to GB/T602, place it in a 100mL volumetric flask, dilute to the scale with water, and shake it.
4.5.2.7 Bromocresol green indicator solution: 0.5g/L. Weigh 0.1g bromocresol green, dissolve it in 2.65mL sodium hydroxide (4g/L) solution, and dilute to 200mL with water. 4.5.3 Instruments and equipment
4.5.3.1 Platinum tower;
4.5.3.2 Spectrophotometer: with 1cm absorption cell. 4.5.4 Analysis steps
4.5.4.1 Drawing of working curve
HG/T 3587---1999
In a set of 150 ml beakers, add 0.00 ml, 2.00 ml, 4.00 ml, 6.00 ml, 8.00 ml, 10.00 ml, 12.00 ml of aluminum standard solution, add water to 20 ml, add 1 ml of ascorbic acid, accurately add 10 ml of mixed reagent solution, and heat in a boiling water bath for 9 minutes. After cooling, transfer to a 100 ml volumetric flask, dilute to the scale with water, and shake. Use a spectrophotometer at a wavelength of 530 nm, use a 1 cm absorption cell, adjust with water, and measure its absorbance. Use aluminum content as the horizontal axis and the corresponding absorbance as the vertical axis to draw a working curve. 4.5.4.2 Preparation of test solution B
Weigh about 0.4g of sample (accurate to 0.01g), place it in a platinum crucible with 5.0g of anhydrous sodium carbonate added, stir well, and cover it with 3.0g of anhydrous sodium carbonate. Melt it in a high-temperature furnace at 950℃～1000℃ for 10min～15min, take it out and shake it well once, or add 2g of anhydrous sodium carbonate and continue to melt until transparent. After taking it out and cooling it, leach the molten block in a plastic beaker, rinse it clean, and heat it in a boiling water bath to dissolve the molten material. After cooling, filter it with medium-speed qualitative filter paper, place the filtrate in a 200mL volumetric flask, dilute it to the scale with water, and shake it well. This solution is test solution B. Keep this solution for the determination of silicon dioxide and magnesium oxide content. 4.5.4.3 Preparation of blank test solution
Except for not adding sample, the amount of other reagents added is exactly the same as the preparation of test solution, and it is treated in the same way as the sample. 4.5.4.4 Determination
Use a pipette to transfer 25 ml of test solution B (4.5.4.2) into a 150 ml conical flask, add 1 drop of bromocresol green indicator, adjust the solution to yellow-green with sulfuric acid (if over-adjusted, adjust back with ammonia solution), and proceed as in 4.5.4.1 from adding 1 ml of ascorbic acid, ....\ to "., measure its absorbance." Perform a blank test at the same time. Find the mass of aluminum in the test solution and blank test solution according to the working curve. 4.5.5 Expression of analytical results
Content of aluminum oxide (Al2O) expressed as mass fraction X. Calculate X according to formula (8): = (m m.)×l,889 × 10-= × 100 = (ml- ms)×1. 511 ,25
m×200
Wherein: mi-—mass of aluminum in the test solution, mg; mo\-mass of aluminum in the blank test solution, mg; m—mass of the sample, g;
1.889—-coefficient of converting aluminum to aluminum oxide. 4.5.6 Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results; for superior products, it shall not exceed 0.0005%, and for first-class products and qualified products, it shall not exceed 0.003%. 4.6 Determination of silicon dioxide content
4.6.1 Summary of the method
Use anhydrous sodium carbonate to melt the sample, leach the melt with water, and then heat it in a boiling water bath to dissolve it. Then filter it and add ammonium molybdate to sulfuric acid to form silicomolybdenum heteropoly acid (silicomolybdenum yellow). In the presence of oxalic acid, add ascorbic acid as a reducing agent to reduce silicomolybdenum yellow to silicomolybdenum blue. Measure its absorbance at a wavelength of 680nm.
4.6.2 Reagents and materials
4.6.2.1 Anhydrous sodium carbonate.
4.6.2.2 Sulfuric acid solution: 1+17.
4.6.2.3 Ammonium molybdate solution: 100g/L.
4.6.2.4 Ascorbic acid solution: 10g/1. 4.6.2.5 Oxalic acid-sulfuric acid mixture.
Weigh 20g oxalic acid and dissolve it in 500ml 1+1 sulfuric acid solution. 4.6.2.6 Silicon dioxide standard solution: 1mL solution contains 0.01mg SiO. 1092
HG/T 3587-1999
Use a pipette to transfer 1 mL of the silicon dioxide standard solution prepared according to GB/T602 into a 100 mL volumetric flask, dilute to the mark with water, and shake to hook. Prepare before use.
4.6.2.7 p-Nitrophenol indicator solution: 1 g/1.4.6.3 Instruments and equipment
Spectrophotometer: equipped with a 2 cm absorption cell.
4.6.4 Analysis steps
4.6.4.1 Drawing of working curve
In a set of 100 mL volumetric flasks, add 0.00 mL, 2.00 ml, 4.00 ml, 6.00 ml, 8.00 ml, 10.00 mL12.00mL silica standard solution, add water to 20mL. Add 1 drop of p-nitrophenol indicator solution, neutralize with sulfuric acid solution until colorless, add 6ml sulfuric acid solution and shake well, then add 2ml ammonium molybdate and shake well. After 20 minutes, add 8mL oxalic acid-sulfuric acid mixed solution and 5ml ascorbic acid solution, shake well, let stand for 30 minutes, dilute with water to the scale, and shake well. Use a spectrophotometer to measure the absorbance of each solution at a wavelength of 680nm with water. Use the silica content as the horizontal axis and the corresponding absorbance as the vertical axis to draw a working curve. 4.6.4.2 Determination
Use a pipette to transfer 20 ml of test solution B (4.5.4.2) into a 100 ml volumetric flask. Follow the steps in 4.6.4.1 from “add 1 drop of p-nitrophenol indicator solution, …” to “measure the absorbance of the solution.” Perform a blank test at the same time. Find out the amount of silicon dioxide in the test solution and the blank test solution according to the working curve. 4.6.5 Expression of analysis results
The silicon dioxide (SiO2) content X expressed as mass fraction is calculated according to formula (9): X2 = (m = mo) × 10 3
m × 200
Where: ml - the mass of silicon dioxide in the test solution, mg; mo
× 100 =
the mass of silicon dioxide in the blank test solution (4.5.4.3), mg; - the mass of the sample in 4.5.4.2, g.
4.6.6' Allowable difference
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results; the superior product shall not exceed 0.0005%, the first-class product and qualified product shall not exceed 0.005%. 4.7 Determination of ferric oxide content
4.7.1 Summary of the method
According to Chapter 2 of GB/T3049-1986.
4.7.2 Reagents and materials
According to Chapter 3 of GB/T3049-1986 and
hydrochloric acid.
4.7.3 Instruments and equipment
According to Chapter 4 of GB/T3049--1986.
4.7.4 Analysis steps
4.7.4.1 Drawing of working curve
According to the provisions of 5.3 of GB/T3049-1986, use a 3cm absorption cell and the corresponding iron standard solution to draw a working curve. 4.7.4.2 Determination
Use a pipette to transfer 100mL of test solution B (4.5.4.2) into a 250mL beaker, adjust the solution to slightly acidic with 1+1 hydrochloric acid solution, cover with surface blood, evaporate in a boiling water bath to a volume of about 40mL, cool to room temperature, transfer all to a 100mL volumetric flask, and measure the absorbance according to the provisions of 5.4 of GB/T3049-1986. According to the working curve, find out the 1093
mass of iron in the test solution and blank test solution.
4.7.4.3 Preparation of empty test solution
HG/T 3587-1999
Except for not adding the sample, the amount of other reagents added is exactly the same as that of the test solution, and the same treatment is carried out at the same time as the sample, and diluted into a volumetric flask of the same volume.
4.7.5 Expression of analytical results
Iron oxide (Fe:O:) X expressed as mass fraction. Calculate according to formula (10): (m) - m.) × 1: 430 × 10 = × 100X
m×200
(ml - m) X 2.86 X 104
Wherein: mi
The mass of iron in the test solution, ug;
The mass of iron in the blank test solution, ug; -The mass of the sample in 4.5.4.2, g;
1.430—The coefficient for converting iron to iron oxide. 4.7.6 Allowable difference
(10)
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results: the superior product is not more than 0.0005%, the standard product is not more than 0.001%, and the qualified product is not more than 0.002%. 4.8 Determination of magnesium oxide content
4.8.1 Summary of method
After melting and dissolving the sample with anhydrous sodium carbonate, measure it with air-acetylene flame at a wavelength of 285.2nm on an atomic absorption spectrophotometer.
4.8.2 Reagents and materials
Magnesium standard solution: 1mL solution contains 0.01mgMg. Use a pipette to transfer 10ml of magnesium standard solution prepared according to GB/T602 into a 100mL volumetric flask, dilute with water to the scale and shake well.
4.8.3 Instruments and equipment
Atomic absorption spectrophotometer: equipped with a magnesium hollow cathode lamp. 4.8.4 Analysis steps
In a set of 100mL volumetric flasks, add 5.00mL of test solution B (4.5.4.2) to each flask, then add 0.00mL, 1.00mL, 2.00mL, and 3.00mL of magnesium standard solution, dilute to the mark with water, and shake. On an atomic absorption spectrophotometer, use an air-acetylene flame, at a wavelength of 285.2nm, and use the blank test solution (4.5.4.3) to zero and measure the absorbance of the above solutions.
Draw a curve with the concentration of the added standard solution as the abscissa and the corresponding absorbance as the ordinate. The curve is reversed and intersected with the abscissa. The intersection point is the content of magnesium to be measured.
4.8.5 Expression of analysis results
The magnesium oxide content (MgO) X expressed as mass fraction. Calculate according to formula (11): X. = mX1. 658X10~3
×100
m×200
Wherein: m1--the mass of magnesium in the test solution obtained by the graphic epitaxy method, mg:--the mass of the sample in 4.5.4.2, g;
the coefficient for converting magnesium into magnesium oxide.
4.8.6 Allowable difference
·（11）
HG/T 3587—1999
The arithmetic mean of the parallel determination results is taken as the determination result. The absolute difference of the parallel determination results; the superior product shall not exceed 0.0005%, the standard product shall not exceed 0.001%, and the qualified product shall not exceed 0.002%. 4.9 Determination of average particle size
4.9.1 Method summary
Inject the treated barium titanate powder into the particle size distribution instrument, and use the liquid phase sedimentation method that combines the centrifugal sedimentation method with the light transmission method to determine the particle size and distribution. Calculate the average particle size of the powder through data processing. 4.9.2 Reagents and materials
4.9.2.1 Sodium hexametaphosphate solution: 10g/L (as dispersant); 4.9.2.2 Glycerol solution:
Take 5mL of glycerol and dilute it to 200ml with water. 4.9.3 Instruments and equipment
4.9.3.1 Disc centrifugal ultrafine particle size distribution instrument (or equipped with a microcomputer): measuring range 0.02μm150μm; 4.9.3.2 Ultrasonic cleaning machine;
4.9.3.3 Agate mortar;
4.9.3.4 Precision thermometer: graduation value 0.1℃; 4.9.3.5 Medical syringe.
4.9.4 Analysis steps
4.9.4.1 Take an appropriate amount of titanic acid sample and put it into the mortar, add a small amount of sodium hexametaphosphate solution to disperse and grind for about 3 minutes. After grinding, add 5mL of water and disperse it in an ultrasonic cleaning machine for 5 minutes before use. 4.9.4.2 After starting the disc centrifugal ultrafine particle size distribution instrument for 20 minutes, inject 200mL of glycerol solution into the instrument disc, add 1mL of water as a buffer, and then use the speed button to partially mix it with the sedimentation liquid, and input the original parameters into the microcomputer. After the instrument is stable, take 0.5mL of the above sample mixture (4.9.4.1) and inject it into the instrument disc for centrifugal sedimentation 3). At this time, the computer starts sampling, processing, printing and other procedures 4), and draws the cumulative percentage of particles, average particle size and particle size distribution results. Note:
3) After injecting the sample solution into the disc, its sedimentation phenomenon should be carefully observed. During the sedimentation process, if the jet phenomenon occurs, the result will be invalid, and the sample needs to be reprocessed and the measurement conditions need to be changed for re-measurement. 4) If the instrument is not equipped with a microcomputer and data processing is required, the average particle size can also be calculated based on the record curve drawn by the recorder. 4.9.5 Expression of analysis results
The average particle size D is calculated according to formula (12):
D-Zd: XW
Wherein: di—-the average particle size of each particle size grade, μm; - the percentage distribution of each particle size grade, %. W.
4.9.6 Permissible difference
The relative deviation of the average particle size measured in the laboratory shall not exceed 1%. 5 Inspection rules
5.1 All items specified in this standard are factory inspection items. 5.2 Each batch of products shall not exceed 1 t.
·(12)
5.3 Determine the number of sampling units according to 6.6 of GB/T6678--1986. When sampling, insert the sampler obliquely from the top of the packaging bag to 3/4 of the depth of the material layer for sampling. After mixing the collected samples, divide them into four parts to no less than 500g, and pack them into two clean and dry wide-mouth bottles with stoppers and seal them. Stick labels on the bottles, indicating: manufacturer name, product name, grade, batch number, sampling date and name of the sampler. One bottle is used as a laboratory sample, and the other is kept for three months for future reference. 5.4 High purity barium titanate for electronic industry shall be inspected by the quality supervision and inspection department of the manufacturer in accordance with the provisions of this standard. The manufacturer shall ensure that each batch of 1095
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products shipped out of the factory meet the requirements of this standard. If one of the indicators in the test results does not meet the requirements of this standard, re-samples shall be taken from the twice-sized packaging for re-inspection. If even one of the indicators in the re-inspection results does not meet the requirements of this standard, the entire batch of products shall be unqualified. 5.5 Use the rounded value comparison method specified in 5.2 of GB1250-1989 to determine whether the test results meet the standards. 6 Marking. Packaging, transportation, storage
6.1 The packaging of high purity barium titanate for electronic industry shall be firmly and clearly marked, including: manufacturer name, factory address, product name, trademark, grade, net content and this standard number.
6.2 Each batch of high purity barium titanate for electronic industry shipped out of the factory shall be accompanied by a quality certificate. The contents include: manufacturer name, factory address, product name, trademark, grade, net content, batch number or production date, proof that the product quality complies with this standard and the number of this standard. 6.3 High-purity barium titanate for the electronics industry is packaged in cardboard barrels. The inner packaging is a polyethylene plastic film bag with a thickness of not less than 0.05mm; the outer packaging is a cardboard barrel with a thickness of not less than 4mm, and its performance and inspection methods should comply with relevant regulations. The net content of each barrel is 25kg. If the user has other requirements for packaging, negotiate to resolve. 6.4 The inner packaging plastic bag of high-purity barium titanate for the electronics industry is tied with polypropylene rope or other ropes of equivalent quality, or sealed with other equivalent methods. The outer packaging barrel is clamped with a clamping ring and the latch is inserted. 6.5 High-purity barium titanate for the electronics industry should be covered during transportation to prevent rain. 6.6 Barium titanate for the electronics industry should be stored in a cool and dry place to prevent rain. 1096
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