GB/T 4734-1996 Chemical analysis methods for ceramic materials and products
Some standard content:
GB/T4734—1996
This standard is based on the arrangement of "Plan for the Formulation and Revision of National Standards and Industrial Standards by the Ministry of Light Industry in 1994" and the requirement for clearing up and rectifying the standards with a long age. It combines and revises GB4734--84 "Chemical Analysis Methods for Daily-use Ceramics Aluminosilicates" and GB4735-84 "Chemical Analysis Methods for Daily-use Ceramics High-silicon Materials and Their Products". During the merger and revision process, the text was strictly written in accordance with GB/T1.1-1993 "Guidelines for Standardization Work Unit 1: Rules for Drafting and Presentation of Standards Part 1: Basic Provisions for Standard Writing". The name of the standard was changed to "Chemical Analysis Methods for Ceramic Materials and Products". The technical content was changed in the following chapters: 8.2, the method of single dehydration with hydrochloric acid and silicon molybdenum blue photometry was cancelled, and the boron removal process in the method of polyethylene oxide condensation and silicon molybdenum blue photometry was added; 8.6, the filtrate of silica was directly used to determine the content of calcium oxide and magnesium oxide during alkali fusion; 8.7, the test solution for potassium and sodium elements was changed from acid solution to aqueous solution, and the drawing of the standard curve was also changed accordingly. From the date of entry into force, this standard will replace GB4734-84 and GB4735-84 at the same time. This standard was proposed by the Light Industry General Association of the People's Republic of China. This standard is technically managed by the National Ceramic Standardization Center. The drafting unit of this standard: China Light Industry General Association Ceramic Research Institute. The main drafters of this standard: Li Shuo, Li Feng, Hong Bin. 31
1 Scope
National Standard of the People's Republic of China
Chemical analysis methods for fonceramic materials and articles
Methods of chemical analysis fonceramic materiats and articlesGB/T4734--1996
GE 473484
Replaces 4735-84
This standard specifies the chemical analysis methods for silicon dioxide, aluminum oxide, iron oxide, titanium dioxide, magnesium oxide, calcium oxide, potassium oxide, sodium oxide, manganese monoxide, phosphorus pentoxide, sulfur trioxide, and ignition loss in fonceramic materials and articles. This standard is applicable to the chemical composition analysis of commercial ceramic materials and articles. 2 Referenced standards
The articles contained in the following standards constitute the articles of this standard through reference in this standard. When this standard is released, the versions requested are valid. All standards will be revised. All parties using this standard should explore the possibility of using the latest version of the following standards. GB6682--92 Specifications and experimental methods for laboratory water GB9721--88 General rules for molecular absorption spectrophotometry of chemical reagents (ultraviolet and visible light parts) GB/T12810--91 Capacity standards and usage methods of laboratory glassware and glass measuring vessels 3~ General provisions
3.1 The water used in this standard shall meet the specifications of grade 3 water in GB668292. 3.2 The reagents used in this standard shall be of analytical grade or higher purity, and the reagents required for the preparation and calibration of standard solutions shall be reference reagents or superior grade pure.
3.3 The glassware used in this standard shall meet the requirements of GB/T12810. 3.4 The nine items of silicon dioxide, aluminum oxide, iron oxide, titanium dioxide, calcium oxide, magnesium oxide, potassium oxide, sodium oxide and ignition loss specified in this standard are included in the routine full analysis items. When other items need to be measured, they must be specifically indicated. 3.5 If the sample to be measured contains other interfering elements, the dry elements must be excluded first. 3.6 The weight during the analysis (the mass difference between the two times before and after the treatment) shall not exceed 0.2 mg. 3.? Parallel tests must be carried out during the analysis, and blank experiments must be carried out at the same time, and the analysis results must be corrected with the reagent blank value. 4 Preparation and calibration of reagents and standard solutions
4.1 Anhydrous sodium magnetic acid.
4.2 Potassium pyrosulfate.
4.3 Sodium fluoride.
4.4 Borax (sodium borate).
4.5 Potassium periodate: solid.
4.6 Mixed flux A Take anhydrous sodium carbonate and borax and fill each portion. 4.7 Mixed flux B: Mix 3 parts of sodium carbonate and 2 parts of magnesium oxide, grind finely. Approved by the State Administration of Technical Supervision on June 25, 199632
Implementation on January 1, 1997
4.8 Hydrochloric acid (density 1.19 g/cm).
GB/T4734—1996
4.9 Hydrochloric acid (1+1): Mix 1 volume of hydrochloric acid (density 1.19 g/cm2) with 1 volume of water. 4.10 Hydrochloric acid (1--5): Mix 1 volume of hydrochloric acid (density 1.19 g/cm2) with 5 volumes of water. 4.11 Hydrochloric acid (1+11): Mix 1 volume of hydrochloric acid (density 1.19 g/cm2) with 11 volumes of water. 4.12 Hydrochloric acid (1+19): Mix 1 volume of hydrochloric acid (density 1.19 g/cm2) with 19 volumes of water. 4.13 Sulfuric acid (density 1.84 g/cm2).
4.14 Sulfuric acid (1+1): Take 1 volume of sulfuric acid (density 1.84 g/cm2) and mix with 1 volume of water. 4.15 Sulfuric acid (1+9): Take 1 volume of sulfuric acid (density 1.84 g/cm2) and mix with 9 volumes of water. 4.16 Sulfuric acid (1+19): Take 1 volume of sulfuric acid (density 1.84 g/cm2) and mix with 19 volumes of water. 4.17
Nitric acid (density 1.42 g/cm2).
4.18 Nitric acid (1+1): Take 1 volume of nitric acid (density 1.42 g/cm2) and mix with 1 volume of water. 9 Nitric acid (1+3): Take 1 volume of nitric acid (density 1.42 g/cm2) and mix with 3 volumes of water. 4.19
Hydrofluoric acid (density 1.14 g/cm\).
Ammonia water (1+1): Take 1 volume of ammonia water (density 0.90g/cm2) and mix with 1 volume of water. 4.21
Ammonia water (1+9): Take 1 volume of ammonia water (density 0.90g/cm2) and mix with 9 volumes of water. 4.22
4.23Sodium hydroxide solution (10%): Take 10g of sodium hydroxide and dissolve in 100mL of water. 4.24Boric acid solution (2%): Take 2g of boric acid and dissolve in 100mL of water. 5Tartaric acid solution (10%): Take 10g of tartaric acid and dissolve in 100mL of water. 4.25
Ammonium molybdate solution (8%): Take 8g of ammonium molybdate and dissolve in 100mL of water. 4.26
Ascorbic acid solution (1%): Take 0.2g of ascorbic acid and dissolve in 20ml of water. Prepare when needed. 4.27
3 Ascorbic acid solution (5%): Take 1g of ascorbic acid and dissolve it in 20mL of water. Prepare it when needed. 4.28
Ethanol (95%).
4.30 Potassium fluoride solution (2%): Take 2g of potassium fluoride and dissolve it in 100mL of water. 4.31 Polyethylene oxide solution (0.05%): Dissolve 0.1g of polyethylene oxide in 200mL of water, add 2 drops of (1+1) hydrochloric acid, and store in a plastic bottle.
4.32 Glacial acetic acid (density 1.05g/cm2). 4.33 Acetic acid-sodium acetate buffer solution (pH～5.5): Weigh 250g of sodium acetate (CH.COONa·3H,O) and dissolve it in 1L of water. Add glacial acetic acid until the pH is～5.5 (measured with precision pH test paper or pH meter). 4.34 Acetic acid-sodium acetate buffer solution (nH~3): Weigh 27g sodium acetate (CH.COONa·3HzO), add 630mL water to dissolve. Add 170mL glacial acetic acid, stir well and add dropwise glacial acetic acid to adjust pH to 3 (measure with precision pH test paper or pH meter). 4.35 Chloroform (99.5%).
4.36 Copper iron reagent (6%): Weigh 6g copper iron reagent, dissolve in 100mL water, filter, and prepare the solution when used. 4.37 Citric acid solution (1mol/L): Weigh 84g citric acid (CHO, HO). Dissolve in 400mL water. 4.38 Phenanthroline solution (0.4%): Dissolve 0.4g of Phenanthroline (Ci2HN2+HO) in 20ml. Anhydrous ethanol, dilute to 100mL with water, and re-prepare when coloring.
4.39 Perfluoric acid (density 1.75g/cm2). 4.40 Diantipyryl methane solution (6%): Take 6g of diantipyryl methane (C2aHa.N.O2), dissolve it in 100mL (1+5) hydrochloric acid, and filter.
4.41 Triethanolamine solution (1+2): Take 1 volume of triethanolamine (density 1.12g/cm) and mix it with 2 volumes of water. 4.42 Ammonia-ammonia chloride buffer solution (pH~10): Weigh 54.0g of ammonium chloride, dissolve it in water, add 350mL of ammonia water, dilute to 1000ml., and store it in a plastic bottle.
4.43 Potassium hydroxide solution (4mol/L): Weigh 224g of potassium hydroxide, dissolve it in 1I. of water. 4.44 Strontium chloride solution (20%): Weigh high-grade pure strontium chloride (SrCls·6H.0) 20g, dissolved in 100mL water, stored in a plastic bottle 33
GB/T4734-1996
Phosphoric acid (1+1): Take 1 volume of phosphoric acid (density 1.70g/cm) and mix with 1 volume of water. Ammonium molybdate solution (5%): Weigh 5g of ammonium molybdate and dissolve in 100mL of water. 4.46
Ammonium vanadate solution (0.125%): Weigh 0.25g of ammonium vanadate, dissolve in 50mL of warm water, add 30mL of concentrated nitric acid, and dilute to 200mL after dissolution.
4.48Barium chloride solution (10%): Weigh 10g of barium chloride and dissolve in 100mL of water. 4.49Silver nitrate solution (1%): Weigh 1g of silver nitrate and dissolve in 100mL of water. 4.50 Sodium carbonate washing solution (2%): Weigh 2g of sodium carbonate and dissolve it in 100mL of water. 4.51 Preparation of silicon dioxide standard stock solution (0.5mg/mL): Weigh 0.5000g of silicon dioxide (99.99%) calcined at 1000℃ for 2h, accurate to 0.0001g, place it in a platinum pot, add 5g of anhydrous sodium carbonate, and stir evenly. Melt at 1000℃ for 10min, cool and place in a 500mL beaker, leaching with boiling water, cool and transfer to a 1L volumetric flask, dilute to scale, shake and store in a plastic bottle. 4.52 Preparation of silicon dioxide standard solution (0.01mg/mL): Use a pipette to accurately transfer 10.0mL of standard storage solution (4.51) into a 500mL volumetric flask, and dilute to the mark with water. 4.53 Preparation of aluminum oxide standard solution (1mg/mL): Weigh 0.5292gL of pure aluminum wire (99.99%). The aluminum wire must be pre-treated: first wash the oxide film with (1+9) hydrochloric acid, then wash with water, then wash with ethanol and ether in turn, air-dry, place in a 30mL beaker, add 50mL of (1+1) hydrochloric acid and 10 drops of concentrated nitric acid, heat to dissolve, and dilute to 1000mL with water. This solution is equivalent to aluminum oxide 1mg/mL. 4.54 Preparation of EDTA standard solution (0.02mol/L): Weigh 37.5g of disodium ethylenediaminetetraacetate, dissolve with a small amount of water, and then dilute to 5000ml with water.
Calibration: Take 2 portions (10.0mL) of aluminum oxide standard solution (4.53) and put them in two 25.0mL conical flasks respectively, add 25mL of EDTA standard solution (0.02mol/L) to each flask, add 50mL of boiling water, 1 drop of methyl orange indicator solution, adjust to slightly orange with (1+9) ammonium hydroxide, then adjust to slightly orange with (1-19) hydrochloric acid, add 2 drops in excess, add 10mL of acetic acid-sodium acetate buffer solution (pH~5.5), heat and boil for 7~10min, remove, cool to room temperature with running water, add 5 drops of xylenol orange indicator solution, and titrate with 0.02mol/L zinc acetate standard solution until the solution changes from yellow to slightly red.
Ta,o, = V, -V,K
Where: TAl,0s——the titration degree of EDTA standard solution on aluminum oxide, mg/mL; the volume of aluminum standard solution taken out, mL, Vr
V2-the volume of EDTA standard solution added, mL; V:-the volume of zinc acetate standard solution consumed by back-titration of excess EDTA standard solution, mLc-the concentration of aluminum standard solution, mg/mL; K-the number of milliliters of EDTA standard solution equivalent to 1 mL zinc acetate standard solution (i.e. the volume ratio when titrating). (1)
4.55 Preparation of zinc acetate standard solution (0.02mol/L): weigh 22g zinc acetate, dissolve in a small amount of water, add 50mL glacial acetic acid, and dilute with water to 5000mL.
To calibrate the volume ratio (K value) of zinc acetate standard solution and EDTA standard solution when they are dropped: Take two portions of 25.0mL of EDTA standard solution (0.02mol/L) and place them in two 250mL conical flasks, add 50mL of boiling water, 10mL of acetic acid-sodium acetate buffer solution, 5 drops of xylenol orange indicator solution to each, and titrate with zinc acetate standard solution (0.02mol/L) until the solution changes from yellow to slightly red. The volume ratio K value of EDTA standard solution and zinc acetate standard solution when they are dropped can be calculated by formula (2): K=
Wherein: V is the volume of EDTA standard solution taken, mL; V, is the volume of zinc acetate standard solution consumed, mL. (2)
4.56 Preparation of standard solution of ferric oxide (0.1mg/mL): Weigh 0.1000g of ferric oxide (spectrally pure) calcined at 400℃ into a beaker, add 30mL (1+1) hydrochloric acid and 5mL concentrated nitric acid, dissolve in a water bath, transfer to a 1L volumetric flask, dilute with water to 34
G/T4734-1996
degrees, and shake. This solution contains 0.1mg of ferric oxide per milliliter. 4.57 Preparation of standard solution of titanium dioxide (10ug/mL): Weigh 0.1000g of pure titanium dioxide calcined at 800℃ for 1h into platinum, add 3g of potassium pyrosulfate, first cool at low temperature, then transfer to a high temperature furnace at 700℃ to melt until transparent. After cooling, transfer the platinum into a 300ml beaker, add 50ml of (1+9) sulfuric acid, heat to dissolve the melt, wash the platinum with (1+9) sulfuric acid and take it out. After the solution cools, transfer it into a 1L volumetric flask, dilute it to the mark with (1+9) sulfuric acid, and spread it evenly. This solution is used as the standard stock solution (100μTi02/mI). Take 10.0mL from the standard stock solution and transfer it into a 100ml volumetric flask, accurately dilute it to the mark with (1+19) sulfuric acid, and use it as the titanium dioxide standard solution (10μTi02/ml)c
4.58 Preparation of calcium oxide standard solution (1mg/ml): weigh 1.7848g of calcium carbonate baked at 110C for 2h, place it in a 250ml beaker, add (11) hydrochloric acid to dissolve it, boil it for a while, cool it to room temperature, transfer it into a 1L volumetric flask, dilute it to the mark with water, and shake it evenly. The solution contains 1mg of calcium oxide per milliliter.
4.59 Preparation of EDTA standard solution (0.01mal/L): Weigh 7.4g of disodium ethylenediaminetetraacetate, place in a 1L beaker, add about 500mL of water, stir until completely dissolved, transfer to a 2L volumetric flask, dilute to scale with water, and add a hook. Calibration: Take 5mL of calcium oxide standard solution (4.58), place in a 250mL beaker, add 5mL of (1+2) triethanolamine solution, 5ml of potassium hydroxide solution (4mol/L), add water to 200mL, add 50mg of calcein-thymol acid complex indicator, and titrate with EETA standard solution (0.01mo1/L) until the fluorescent green disappears and suddenly turns into rose red, which is the end point. The molar concentration M of the EDTA standard solution and its titer Tcno and TMo for calcium oxide and magnesium oxide are expressed by formula (3), (4) and (5): W
Tcao 56.08 M
TMa0 = 40.30 M
wherein, M is the molar concentration of the EDTA standard solution, mol/L; W is the mass of calcium oxide contained in the calcium standard solution, mg; V is the volume of the EDTA standard solution consumed, mL56.08 is the molar mass of calcium oxide, g/mol; 40.30 is the molar mass of magnesium oxide, g/mol; Tcan is the titer of the EDTA standard solution for calcium oxide, mg/mL; TM is the titer of the EDTA standard solution for magnesium oxide, mg/mL. 3
（5）
4.60 Preparation of calcium oxide standard solution (0.1mg/mL) Dilute the calcium oxide standard solution (4.58) accurately by 10 times to make a concentration of 1mL containing 0.1mg calcium oxide.
4.61 Preparation of magnesium oxide standard solution (0.1mmg/mL): Weigh 0.1000g of magnesium oxide that has been calcined at 950℃ for 30min, put it into a 250mL beaker, add 10mL of (1+1) hydrochloric acid, dissolve it under slight heat, cool it down, transfer it into a 1L volumetric flask, dilute it to the scale with water, and shake it well. 1mL of this solution contains 0.1mg magnesium oxide.
4.62 Preparation of mixed stock standard solution of potassium oxide and sodium oxide (K.01mg/mL+Naz01mg/ml): Weigh 1.5830g of potassium chloride and 1.8860g of sodium chloride dried at 150C for 2h respectively, put them in the same beaker, add water to dissolve, transfer to a 1L volumetric flask, add water to dilute to the scale, shake well, this solution contains 1mg of potassium oxide and 1mg of sodium oxide per milliliter. 4.63 Preparation of potassium oxide and sodium oxide mixed reference standard solution (K.0 0.1 mg/mL + Na20 0.1 mg/mL): Use a pipette to take 50.0 ml of the prepared standard solution (4.62) into a 500 ml volumetric flask, and dilute to the mark with water. This solution contains 0.1 mg potassium oxide and 0.1 mg sodium per ml.
4.64 Preparation of manganese oxide standard solution (0.1 mg/mL): Weigh manganese sulfate MnS0,*H0)0.1191g, dissolve in water, add (1+1) sulfuric acid 1mL, transfer to 500ml volumetric flask, dilute to scale with water, shake well, this solution 1ml. contains MnO 0.1 mg.
4.65 Preparation of phosphorus pentoxide standard solution (0.1mg/mL): weigh 0.1917 potassium dihydrogen phosphate (KH2PO), dissolve in 300mL water, transfer to 1［. volumetric flask, dilute to scale with water, shake well. This solution 1ml. contains 0.1mg phosphorus pentoxide. 35
GB/T4734-—1996
4.66 p-nitrophenol indicator solution (0.5%): weigh 0.5 more nitrophenol, dissolve in 100mL ethanol. 4.67 Xylenol orange indicator solution (0.2%): weigh 0.2g of xylenol orange and dissolve it in 100mL of water, store it in a brown bottle, keep it in a cool place, and store it for no more than one month. If it turns red, neutralize it with (1+19) hydrochloric acid to yellow. 4.68 Mixed indicator of calcein and thymol acid: weigh 0.1g of calcein, add 0.06g of thymol acid and 10g of potassium chloride, and grind it into fine powder. 4.69 Methyl thymol blue complex indicator: weigh 0.2g of methyl thymol blue, add 20g of potassium nitrate, and grind it into fine powder. 4.70 Methyl orange indicator solution (0.1%): weigh 0.1g of methyl orange and dissolve it in 100mL of water. 4.71 Silica gel.
5 Method Summary
5.1 Ignition Loss
The sample is ignited at 1025℃25℃, and the weight lost is the ignition loss. 5.2 Silicon Dioxide
5.2.1 Polyethylene oxide condensation and silicon blue photometry: The sample is melted with sodium carbonate (or mixed flux), and in a hydrochloric acid medium, polyethylene oxide is used to condense and precipitate silica, ignite and precipitate, and weigh. Use hydrofluoric acid to volatilize silicon dioxide, then ignite and weigh, and the main silicon dioxide content is calculated from the loss. Take the filtrate and measure the residual silicon dioxide content in the filtrate by silicon clamp blue photometry. The sum of the two is the silicon dioxide content of the sample
5.2.2 Hydrofluoric acid method: After measuring the ignition loss, add fluoric acid to volatilize silicon dioxide, ignite and weigh, and the silicon dioxide content is calculated from the loss.
5.3 Aluminum oxide
5.3.1 Copper-iron reagent-chloroform extraction and separation, EDTA complexometric titration: Take the filtrate after silicon separation or the solution of the dissolved residue after hydrofluoric acid silicon removal) and adjust the solution acidity to 2.5mol/1. Use copper-iron reagent and chloroform to extract and separate interfering elements such as iron and titanium. In an excess EDTA standard solution, use xylenol orange as an indicator and use zinc acetate to back-titrate the excess EDTA. 5.3.2 Fluoride substitution, EDTA complexometric titration: Take the effluent after silicon separation (or the filtrate of the residue dissolved with hydrochloric acid after silicon removal with hydrofluoric acid), add excess EDTA, adjust the pH to 4, so that it can completely complex with aluminum, titanium and other ions, use dimethyl orange as the indicator, back-titrate the excess ETA with zinc acetate standard solution, then add sodium fluoride to displace the EDTA complexed with aluminum and titanium, and then continue to titrate the aluminum and titanium content with zinc acetate standard solution:
5.4 Ferrous oxide
5.4.1 o-Phenanthroline photometric method: Separate the filtrate of alkali fusion or acid fusion, mask the coexisting interfering ions with citric acid, reduce the trivalent iron to divalent iron with ascorbic acid, and then add o-phenanthroline to the solution with pH to 3 to form an orange-red complex with Fe2+, and measure the absorbance at 510nm on a spectrophotometer.
5.4.2 Flame atomic absorption spectrophotometry: Decompose the sample with hydrofluoric acid and perchloric acid, evaporate it and then dissolve it in hydrochloric acid. Use an atomic absorption spectrophotometer to measure the absorbance of iron at 248.3nm. 5.5 Titanium dioxide
Diantipyryl methane spectrophotometry: Tetravalent titanium ions and diantipyryl methane form a stable yellow complex in the presence of hydrochloric acid with an acidity of 1.22.5 mol/L. Use ascorbic acid to eliminate the interference of iron, and measure the absorbance of the titanium yellow complex at the upper wavelength of 390nm on the spectrophotometer.
5.6 Calcium oxide and magnesium oxide
5.6.1 EDTA complexometric titration: Take two portions of the alkali-fused filtrate or the acid-soluble solution, add triethanolamine to one portion to mask iron, aluminum, and titanium: add calcein and thymol acid mixed indicator in a strong alkaline solution, and use EDTA standard solution to titrate calcium. Use triethanolamine as a masking agent in the other portion. Add methylthymol blue indicator in an ammoniacal solution, and use EDTA standard solution to titrate the total amount of calcium and magnesium, and use the difference subtraction method to determine the content of magnesium oxide.
5.6.2 Flame atomic absorption spectrophotometry: Place the test solution on an atomic absorption spectrophotometer, and measure the absorbance of calcium and magnesium at a wavelength of 422.7nm using a calcium hollow cathode lamp and a magnesium hollow cathode lamp at a wavelength of 285.2nm, respectively. 36
5.7 Potassium oxide and sodium oxide
GB/T4734—1996
Flame photometry: Determine the relative radiation intensity of the test solution and the standard solution on a flame photometer to calculate the content of potassium oxide or sodium oxide.
5.8→ Manganese oxide
The sample is decomposed with sulfuric acid-hydrofluoric acid. In a phosphoric acid medium, potassium periodate is used to oxidize low-valent manganese into purple-red permanganic acid. The absorbance of the solution is measured at a wavelength of 530nm using a spectrophotometer. 5.9 Phosphorus pentoxide
The sample is decomposed with nitric acid-hydrofluoric acid. In a nitric acid medium, phosphoric acid reacts with vanadate and molybdate to form a yellow complex. The absorbance of the solution is measured at 390nm on a spectrophotometer.
5.10 Sulfur trioxide
The sample is melted with a sodium carbonate-magnesium oxide mixed flux. After all the sulfur is converted into soluble sulfate, barium chloride is added to the hydrochloric acid medium to make the sulfur form barium sulfate precipitation. After burning at 800℃, weigh and calculate the percentage of sulfur trioxide. 6 Instruments and equipment
6.1 Atomic absorption spectrophotometer: The sensitivity of iron at a wavelength of 248.3nm should be higher than 0.1μg/mL (1% absorption): The sensitivity of calcium at a wavelength of 422.7nm should be higher than 0.1μg/mL (1% absorption), and the sensitivity of magnesium at a wavelength of 285.2nm should be higher than 0.1μg/ml (1% absorption).
6.2 Flame photometer: Use petroleum gas, liquefied petroleum gas or coal gas as fuel gas. Its sensitivity to potassium oxide or sodium oxide should be higher than 0.05 μg/mL per division.
6.3 Spectrophotometer: in accordance with GB9721. 7 Preparation of test samples
7.1 The testing unit shall take samples according to the provisions or technical requirements in the product standard to make them representative of the whole. 7.2 The testing unit shall take samples according to the empirical formula (6): Q= kd?
Where: Q—representative minimum weight after treatment, kg; k—characteristic constant, which is set as 0.2 in this standard; d—maximum particle size after treatment, mm,
(6)
The samples to be tested shall be crushed, sieved, and reduced to be analyzed so that they do not lose the representativeness of the original samples. 7.3 The maximum particle size of the analysis sample shall be less than 0.09 mm, and the minimum weight shall not be less than 50 g. Before the determination of each component, the analysis sample shall be dried at 105-110℃ for 2-3 hours.
7.4 Preparation of alkali fusion sample
Weigh 0.5g of sample, accurate to 0.0001g, and place it in a platinum crucible. Take 4g of sodium carbonate (or 3g of mixed flux), mix two-thirds of the flux with the sample, and cover the remaining one-third on top. Heat at low temperature first, gradually increase to 1000℃, melt for 10-15min, take out and cool, immerse the molten block in a 500mL beaker with hot water, add 20mL of hydrochloric acid (density 1.19g/cm3), cover with watch, after the reaction stops, wash the crucible, cover and watch glass with hydrochloric acid (1+1) and hot water, move the beaker to a boiling water bath, and concentrate until silica gel precipitates with only a small amount of liquid (about 10mL). Remove, cool to room temperature, add 10mL of propylene glycol to remove boron, shake well, then add 10mL of polyethylene oxide solution (0.05%), stir well, let stand for 5min, add 10mL of boiling water to dissolve the salts, then use slow quantitative filter paper to filter into a 250mL volumetric flask, wash with hot hydrochloric acid (1+19) 5-6 times, and finally use a small piece of filter paper and a glass rod with a rubber head to scrub the beaker to transfer the precipitate completely. Wash the precipitate with hot water until there is no chloride ion, transfer the precipitate into a constant weight platinum crucible, add 1 drop of sulfuric acid (1+1), cover and leave a gap, first carbonize and then ash to white, then put it in a high temperature furnace and burn it at 950-1000℃ for 1h, transfer it to a dryer and cool it to room temperature, repeat the operation until constant weight, record it as m. After wetting the above precipitate, add 5 drops of sulfuric acid (1+1) and hydrofluoric acid (density 1.14g/cm2) 10mL first small fire 37
GB/T 47341996
gradually raise the temperature until white smoke begins to emit, remove and cool, then add 3 drops of sulfuric acid (1+1), 5mL of hydrofluoric acid, evaporate until white smoke disappears, transfer to 950~1000C blast furnace and burn for 1h, transfer to dryer and cool to room temperature, weigh, repeat until constant weight, record as m2 (if the residue exceeds 10mg, re-weigh and re-work), use 1g of potassium pyrosulfate to melt the residue at 500-600C, after cooling, heat and dissolve with a few drops of hydrochloric acid (1+1) and a small amount of water, add filtrate, dilute to scale, this solution is called test solution A. This solution is used for the determination of residual SiO, AlOs, FeaO3.TiO::CaO, MgO content.
7.5 Preparation of acid-soluble samples
When the SiO2 content is above 98%, this method can be used to prepare the test solution. Weigh 1g of the sample, accurate to 0.0001g, place it in a platinum glass, add water to moisten it, add 1mL perchloric acid (density 1.75g/cm2) and 10mL hydrofluoric acid (density 1.14g/cm2), cover the tower lid and leave a gap, heat for about 15min without boiling, open the ground cover and wash twice with a small amount of water (the washing liquid is added to the culture medium), carefully fry on a normal electric heater until it is almost dry, and remove the crucible. After it cools down slightly, rinse the crucible wall with a small amount of water, add 3mL hydrofluoric acid and evaporate it to almost dryness, add 4 drops of perchloric acid after it cools down slightly, continue to evaporate to dryness, add 10mL of hydrochloric acid (1+1) after it cools down slightly, and place it on a normal electric heater to heat and decompose until the solution is clear. Wash the solution into the beaker with hot water. After cooling, transfer it to a 250mL volumetric flask, dilute it to the mark with water, and shake it. This solution is called test solution B. The above solution is used for the determination of Al2O, FezO3, TiO, CaO, MO, K.O, and NazO contents.
8 Analysis steps
8.1 Loss on ignition
8.1.1 Determination: Weigh 1g of the sample to an accuracy of 0.0001g, place it in a crucible that has been burned to constant weight, and place the lid on the crucible obliquely. Place it in a high-temperature furnace, gradually raise the temperature from low temperature to 1025±25, burn for 1h, take it out and cool it to room temperature in a desiccator, weigh it, and burn it for 15min. Weigh it, and repeat the operation until it remembers the weight. 8.1.2 Expression of results
The percentage of loss on ignition is calculated according to formula (7): Loss on ignition (%) == × 100
Where: Twist the mass of the sample before ignition, &
m the mass of the sample after ignition, g
m the mass of the sample + g.
The result should be expressed to two decimal places.
8.2 Silicon dioxide
8.2.1 Polyethylene oxide condensation and silicon molybdenum blue photometry method 8.2.1.1 Determination of primary silicon dioxide bonds: Follow the steps of ?.4. +**+(7)
8.2.1.2 Determination of residual silicon dioxide: Take 10.0 mL of filtrate A and put it in a plastic beaker, add 5 mL of potassium fluoride solution (2%), mix well and place for 10 minutes, add 5 mL of boric acid solution (2%), shake well, add 1 drop of p-nitrophenol indicator solution. Neutralize dropwise with sodium hydroxide solution (10%) until yellow, then neutralize with hydrochloric acid (1+1) until the yellow disappears, add 4 mL more, add 4 mL of ammonium sulfate solution (8%) and 8 mL of ethanol (95%), shake well. Place at 20-40°C for 15 minutes, then add 20 mL of hydrochloric acid (1+1), 5 mL of tartaric acid solution (10%) and 5 mL of ascorbic acid solution (5%), transfer to a 100 mL volumetric flask, dilute to the mark, and shake well. Leave it for about 1 hour, and use the reagent blank as a reference to measure the absorbance on a spectrophotometer at a wavelength of 650rm with a 2cm colorimetric blood. The corresponding silica concentration is obtained from the standard curve, and then the residual silica content in the filtrate is calculated by formula (9). 8.2.1.3 Drawing of standard curve: Accurately take 5.0, 7.0, 9.0, 11.0, 13.0, and 15.0 mL of the silica standard solution (4.52) (0.01m/mL). Transfer them into 6 plastic cups respectively, and then follow the steps in 8.2.1.2, use the reagent blank as a reference, measure its absorbance, and draw the absorbance-SiO2 concentration standard curve. 38
8.2.1.4 Expression of results
The main silica content is calculated according to formula (8): GB/T 4734--1996
SiO:(main)(%) = m1=m × 100
Wherein: m-wwW.bzxz.Net
Precipitation and crucible mass, g:
Residue and crucible mass after hydrofluoric acid treatment, g; m——sample mass, g.
The result should be expressed to two decimal places.
The residual silica content is calculated according to formula (9): Si0,(residual)(%) = ×10 × 25 × 100m
Wherein: c-silicon dioxide concentration found from the standard curve, mg/100mL, m
-sample mass, g.
The result should be expressed to two decimal places.
The total amount of silicon dioxide is calculated according to formula (10):
Sio, (total) (%) = SiO, (main) (%) + SiO, (residual) (%) The result should be expressed to two decimal places.
8.2.2 Hydrofluoric acid method
When the SiO, content is above 98%, this method can be used. · (8)
8.2.2.1 Moisten the sample after the ignition loss measured in 8.1 with a few drops of water, then add 10.5mL sulfuric acid (1+10.5mL), 10mL hydrofluoric acid (density 1.14g/cm3), cover the crucible with a small gap, heat for about 15min without boiling, open the crucible and wash twice with a small amount of water (the washing liquid should be put into the glass), evaporate carefully on an ordinary electric heater until almost dry, remove, cool slightly and rinse the glass wall with water, then add 3mL hydrofluoric acid (density 1.14g/cm3) and evaporate to dryness, drive away all sulfur trioxide, place in a high-temperature furnace, gradually increase the temperature to 950~1000℃, burn for 1h, take out and place in a desiccator to cool to room temperature and weigh, repeat this operation (re-burning for 30min). 8.2.2.2 Expression of results
Silicon dioxide content is calculated according to formula (11):
sio,(%) = m=m2 × 100
Mass of crucible and sample after calcination, g:
Where: m-
m2-——Mass of crucible after hydrofluoric acid treatment, g; m——Mass of sample, B.
The result should be expressed to two decimal places.
(11)
8.3 Aluminium oxide
The determination of aluminium oxide is carried out by using copper iron reagent-chloroform extraction separation, EDTA complexometric titration or fluoride substitution, EDTA complexometric titration.
GB/T 4734—1996
8.3.1 Copperferric reagent-chloroform extraction and separation, EDTA complexometric titration 8.3.1.1 Determination: Take 25.0mL of test solution A or B in a 250mL separatory funnel, add 10mL of hydrochloric acid (1+1), 5mL of copperferric reagent solution (6%), 20mL of chloroform, screw the stopper, shake for 1min, and repeat the operation until the chloroform layer is colorless. After separation, remove the chloroform layer, put the aqueous phase into a 500mL conical flask, rinse the separatory funnel and stopper with water, and add 30mL of EDTA standard push solution (0.02mol/L) (AlO: content is relatively high). When the temperature is high, the number of milliliters of EDTA standard solution can be appropriately increased), heat the solution to keep it at about 50°C, add 1 drop of methyl orange indicator solution (0.1%), adjust it to orange with ammonia water (1+9), and then adjust it to slightly red with hydrochloric acid (1+19), add 2 drops in excess, heat and boil for 7-10 minutes, cool to room temperature, add 10mL of acetic acid-sodium acetate buffer solution, 5 drops of xylenol orange indicator solution, and titrate with zinc acetate standard solution (0.02mol/L) until the color suddenly changes from yellow to slightly red, and do a blank test at the same time. 8.3.1.2 Result expression
The aluminum oxide content is calculated by formula (12): (VV)KTa × 100
Al,0(%)=
ma × 103
Where: V-.-The volume of zinc acetate solution consumed in the blank test, mL; V,-The volume of zinc acetate solution consumed in the titration of the test solution, mLTal0-The titer of EDTA standard solution to aluminum oxide, mg/mLK-The number of milliliters of 1ml zinc acetate solution equivalent to EDTA standard solution (i.e., the volume ratio when titrating); m-The mass of the sample, g;
α-The ratio of the volume of the sample solution to the total volume. The result should be expressed to two decimal places.
（12）
8.3.2 Complexometric titration method using sodium fluoride to replace EDTA8.3.2.1 Determination: Take 25.0mL of test solution A or B and place it in a 500mL conical flask. Add EDTA standard solution (0.02mol/L)30mL (A1O, when the content is high, the number of milliliters of EDTA standard solution can be appropriately increased), heat the solution to keep it at about 50℃, add 1 drop of methyl orange indicator solution (0.1%), use ammonia water (1+9) to adjust the solution to orange, then use hydrochloric acid (1+19) to adjust it to slightly red, and then add 2 drops in excess. At this time, the pH of the solution is about 3.8~4. Boil slightly for 3~5min, cool to room temperature with running water, add 10mL of acetic acid-sodium acetate buffer solution (pH~5.5), 5 drops of xylenol orange indicator solution (0.2%), and titrate with zinc acetate standard solution (0.02mol/L) until it changes from yellow to slightly red. Add 2g of sodium fluoride. If the color of the test solution is not yellow after the addition of sodium fluoride, add hydrochloric acid (1+19) dropwise to make it yellow. Heat and boil for 5min, cool to room temperature with running water, add 5ml of acetic acid-sodium acetate buffer solution (pH~5.5), and then add 1 drop of xylenol orange indicator solution (0.2%), and continue to titrate with zinc acetate standard solution (0.02mol/L) until the solution changes from yellow to slightly red. 8.3.2.2 Result Expression
The content of aluminum oxide is calculated by formula (13): A1,0,(%) =
VKTALO
× 100 - Ti0,(%) X 0. 638
ma × 103
The volume of zinc acetate standard solution consumed for the second time, mL Where: -
-The titer of EDTA standard solution to aluminum oxide, mg/mI, Taln--
-1mL zinc acetate standard solution is equivalent to the number of milliliters of EDTA standard solution (i.e. the volume ratio when the two are dropped); Sample mass:
The ratio of the volume of the sample solution to the total volume; α
0.638--The coefficient of converting titanium dioxide to aluminum oxide. The result should be expressed to two decimal places.
8.4 Ferric oxide
The content of ferric oxide shall be determined by o-phenanthroline photometry or flame atomic absorption spectrophotometry. 1
8.4.1 o-phenanthroline photometry
GB/T 4734-1996
8.4.1.1 Determination: Take 25.0mL of test solution A or B in a 100mL volumetric flask (when the Fe2O: content is high, less sample can be added and the dilution can be increased), add 3mL of ascorbic acid solution (1%), shake well, let stand for 10min, add 3mL of citric acid solution (1mol/), 1 drop of p-nitrophenol indicator solution (0.5%, add ammonia water (1+1) to adjust to yellow, add 10 drops of hydrochloric acid (1+1), add 5mL of sodium acetate buffer solution, o-phenanthroline solution (0.4%, 3mL), dilute to the scale with water. Let stand for 15min, use the reagent blank as reference in the spectrophotometer, and use 1cm colorimetric blood at a wavelength of 510nm, Determine its absorbance. 8.4.7.2 Drawing of standard curve: Take 50 ml of ferric oxide standard solution (456) and dilute it to 500 ml with water. This solution contains 0.01 mg of ferric oxide per ml.
Take 5.0, 10.0, 15.0, and 20.0 ml of the standard solution containing a.01 mg of ferric oxide per ml, and place them in 50 ml volumetric flasks respectively. Follow the steps in 8.4.1.1. Measure the absorbance with the reagent blank as the ratio, and draw the absorbance-Fe20: concentration standard curve. 8.4.1.3 Expression of results
The content of ferric oxide is calculated by formula (14): ma×10g×100
Fe.O,(%) m=
Wu Zhong: c is the concentration of ferric oxide found on the standard curve, m/100 m is the mass of the sample,
a is the ratio of the volume of the sample to the total volume. The result should be expressed to two decimal places.
##**( 14 )
8.4.2 Flame atomic absorption spectrophotometry
8.4.2.1 Determination: Weigh 0.5g of the sample, accurate to 0.0001g, put it in platinum, moisten it with water, add 20 drops of perchloric acid (density 1.75gcm2), 10 drops of nitric acid (density 1.42g/cm), 10ml of hydrofluoric acid (density 1.14g/cm), carefully heat and evaporate to dryness, cool, if the decomposition is not complete at one time, repeat once and heat until the white smoke disappears. Cool, add 20mL of hydrochloric acid (1+1), add appropriate amount of water, heat to dissolve, filter into a 250mL volumetric flask, dilute to the mark with water, this solution is test solution C. Take 25.0mL of test solution C in 10 0mL volumetric flask (when the Fe2O: content is high, less sampling can be done and more dilution can be done), keep the test solution at 4% hydrochloric acid acid.
On the adjusted atomic absorption spectrophotometer, use an iron hollow cathode lamp, acetylene-air flame at a wavelength of 248.3nm, and measure its absorbance with the reagent blank as a reference.
8.4.2.2 Drawing of standard curve: Take 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0mL of ferric oxide standard solution (4.56), place in 10 100mL volumetric flasks, add 8mL of hydrochloric acid (1+1) to each, dilute to the scale with water, and shake well. On a debugged atomic absorption spectrophotometer, use an iron hollow cathode lamp, at a wavelength of 248.3n, use an acetylene-air flame, measure the absorbance with the reagent blank as the integral ratio, and draw an absorbance-Fe2O concentration standard curve. 8.4.2.3 Result expression
The percentage of ferric oxide is calculated by (15): ev
ma×10%×100
FeOt%)
Where: .The concentration of ferric oxide in the test solution is obtained from the standard curve, /mL. V—the volume of the test solution, mL
0—the ratio of the volume of the test solution to the total volume: m mass of the sample + g.
The result should be expressed to two decimal places.
8.5 Titanium dioxide
GB/T 4734-1996
8.5.1 Take 20.0 mL of test solution AB and put it into a 50 mL volumetric flask (when the TiO content is high, less sample can be taken and the dilution can be increased), add 2 mL of ascorbic acid solution (5%), shake the hook, add 7 mL of hydrochloric acid (1+1) and 8 mL of diantipyrine methane solution (6%), dilute to the scale with water, shake the hook, and leave it for 1 minute. Take the reagent blank as the reference and measure its absorbance at a wavelength of 390 nm on a spectrophotometer using a 2 cm colorimetric III, and find the corresponding titanium dioxide concentration on the standard curve. 8.5.2 Drawing of standard curve: Add 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0 mL of titanium dioxide standard solution (10 gTiO/mL) to 8 50 mL volumetric flasks respectively, make up to 8 mL with sulfuric acid (1+19), add 10 mL of water, and proceed as in 8.5.1 to draw the absorbance-TiO concentration standard curve. 8.5.3 Nested expression
The percentage of titanium dioxide is expressed by formula (16): TiO.(%) × 108
Where: The concentration of titanium dioxide obtained from the standard curve, /50 mL sample mass, g:
a is the ratio of the volume of the test solution to the total volume. The result should be expressed to two decimal places.
8.6 Calcium oxide and magnesium oxide
Calcium oxide and magnesium oxide are determined by EDTA complexometric titration or flame atomic absorption spectrophotometry. 8.6.1 EDTA complexometric titration
+***216)
8.6.1.1 Determination of calcium oxide: Take 25.00 mL of test solution A or B in a 250 mL beaker, add 1 drop of methyl orange indicator solution (0.1%), 5 mL of triethanolamine solution (1+2), add potassium hydroxide solution (4 mol/L) until it turns yellow, add an excess of 10 mL, add water to less than 200 mL and proceed according to the steps in 4.59, and do a blank test at the same time. 8.6.1.2 Determination of magnesium oxide: Take 25.0 mL of test solution A or B, add 5 mL of triethanolamine solution (1+2), 25 mL of ammonia-ammonium chloride buffer solution (pH~10), and 25 mL of ammonia water (1+1), make up to 200 mL, add 30 mL of methylthymol blue indicator, and titrate with EDTA standard solution (0.01 mol/L.) until the blue color disappears and suddenly turns into light gray or colorless. This is the end point. Perform a blank test at the same time. 8.6.1.3 Expression of results
The percentage of calcium oxide and magnesium oxide is calculated by (17) and (18) respectively: (V- Ve)Tco × 100
CaO(%) =
ma × 103
Where: V,The volume of EDTA standard solution consumed in titrating the test solution, mLV, the volume of EDTA standard solution consumed in the blank test, mL, Tcan, the titer of EDTA standard solution to calcium oxide, mg/mLm-mass of the sample, g
—the ratio of the volume of the test solution to the total volume. The result should be expressed to two decimal places.
Mgo0(%) [V -V)=i )JTue × 100ma X 10
（18)
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