Some standard content:
ICS 91. 100. 10
National Standard of the People's Republic of China
GB/T5484—2000
Methods for chemical analysis of gypsum
gypsum2000-12-18 issued
2001-07-01 implementation
State Administration of Quality and Technical Supervision
issued/9
GB/T5484—2000
referenced standards
basic requirements for the test
reagents and materials
instruments and equipment
sample preparation
determination of adhering water (standard method)
determination of crystal water (standard method)
determination of acid insoluble matter (standard method)
determination of sulfur trioxide (standard method)·
determination of calcium oxide (standard method).
determination of magnesium oxide (standard method)||t t||Determination of ferric oxide (standard method)
Determination of aluminum oxide (standard method)
Determination of titanium dioxide (standard method)
Determination of potassium oxide and sodium oxide (standard method)17
Determination of silicon dioxide (substitute method)
Determination of ferric oxide (substitute method)
Determination of aluminum oxide (substitute method)
Determination of fluorine (substitute method)
Determination of phosphorus pentoxide (substitute method)
Determination of loss on ignition (substitute method)
GB/T5484—2000
This standard is a revised version of GB/T5484--1985 "Chemical analysis methods for gypsum and anhydrite". Taking into account the characteristics of my country's stone varieties, this standard specifies the standard method for chemical analysis of gypsum and the alternative method that is considered to give equivalent results under certain conditions. In case of dispute, the standard method shall prevail. The determination of crystal water in the standard method is the same as the method specified in ISO3052:1974 (E); the determination method of adhesion water and sulfur trioxide refers to ASTMC471M~1995 standard; the determination method of ferric oxide refers to JISR9101 standard. This standard supplements the determination methods of fluorine, phosphorus, titanium dioxide, potassium oxide, sodium oxide and ignition loss, and cancels the analysis method of sulfur trioxide by ion exchange method in GB/T5484--1985 standard. In the scope of the standard, add "This standard is applicable to the chemical analysis of natural gypsum and anhydrite" after "This standard is applicable to the chemical analysis of natural gypsum and anhydrite". This standard replaces GB/T5484-1985 "Chemical Analysis Method of Gypsum and Anhydrite" from the date of implementation. This standard is proposed by the State Bureau of Building Materials Industry. This standard is under the jurisdiction of the National Cement Standardization Technical Committee. The drafting unit of this standard is the Institute of Cement Science and New Building Materials, China Building Materials Science Research Institute. The main drafters of this standard are Tang Juping, Luo Bangqian, Cui Jian and Liu Wenchang. This standard was first issued in 1985.
This standard is entrusted to the Institute of Cement Science and New Building Materials, China Building Materials Science Research Institute for interpretation. 1 Scope
National Standard of the People's Republic of China
Methods for chemical analysis of gypsum
Methods for chemical analysis of gypsum This standard specifies the methods for chemical analysis of gypsum. GB/T5484—2000
Replaces GB/T5484--1985
This standard applies to the chemical analysis of natural gypsum and anhydrite. The chemical analysis of chemical gypsum and other gypsums can refer to this standard. 2 Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard was published, the versions shown were valid. All standards are subject to revision. Parties using this standard should explore the possibility of using the latest version of the following standards. GB/T2007.1-1987 General Rules for Sampling and Sample Preparation of Bulk Mineral Products Manual Sampling (neqISO1422:1986) 3 Basic Requirements for Tests
3.1 Number of Tests and Requirements
The number of tests for each determination is specified to be two. The average value of the two tests is used to express the test results. When conducting chemical analysis, blank tests should be conducted simultaneously for each determination, and the measured results should be corrected. 3.2 Expression of mass, volume, volume ratio, titer and results The unit of mass is expressed in "grams", accurate to 0.0001g: the unit of volume of the burette is expressed in "milliliters", accurate to 0.05mL. The unit of titer is expressed in "milligrams/milliliter (mg/mL)", and the titer and volume ratio are rounded off to retain four significant figures. All analytical results are expressed in percentages to two decimal places. 3.3 Allowable Difference
The allowable differences listed in this standard are all absolute deviations, expressed as percentages. The allowable difference of the same laboratory means that when the same analytical laboratory and the same analyst (or two analysts) use this standard method to analyze the same sample, the results of two analyses should meet the allowable difference regulations. If it exceeds the allowable range, a third measurement (or a third person's measurement) should be carried out within a short period of time. If the difference between the measurement result and the previous two or any one analysis result meets the allowable difference regulations, the average value should be taken. Otherwise, the cause should be found and the analysis should be carried out again according to the above regulations. The allowable difference of different laboratories means that when two laboratories use this standard method to analyze the same sample, the difference between the average values of the obtained analysis results should meet the allowable difference regulations. 3.4 Burning
Put the filter paper and precipitate in a pre-burned and constant-weight crucible and dry them. Slowly ash in an oxidizing atmosphere without generating flames. After ashing until there are no black carbon particles, put it in a muffle furnace and burn it at the specified temperature. Cool to room temperature in a dryer and weigh it. 3.5 Constant weight
After the first burning, cooling and weighing, check the constant weight by burning for 15 minutes each time, then cooling and weighing. When the difference between two consecutive weighings is less than 0.0005g, the constant weight is reached. 3.6 Check CI- ion (silver nitrate test) Approved by the State Administration of Quality and Technical Supervision on December 18, 2000 and implemented on July 1, 2001
GB/T5484—2000
After washing the precipitate several times as specified, rinse the lower end of the funnel with a few drops of water, wash the filter paper and precipitate with a few milliliters of water, collect the filtrate in a test tube, add a few drops of silver nitrate solution (see 4.8), and observe whether the solution in the test tube is turbid. If turbid, continue washing and check regularly until the silver nitrate test is no longer turbid.
4 Reagents and Materials
During the analysis, only distilled water or water of equivalent purity should be used; the reagents used should be analytically pure or superior grade reagents. Reagents used for calibration and preparation of standard solutions should be reference reagents unless otherwise specified. Unless otherwise specified, % means "% (m/m)". The commercially available concentrated liquid reagents used in this standard should have the following density p (20C, unit: g/cm) or concentration % (m/m):
Hydrochloric acid (HCl)
Hydrofluoric acid (HF)
Nitric acid (HNO,)
Sulfuric acid (H2SO,)
1.18g/cm3~1.19g/cm2 or 36%~38%1.13g/cm2 or 40%
1.39g/cm3~1.41g/cm2 or 65%~68%1.84g/cm or 95%~98%
Glacial acetic acid (CH, COOH)1.049g/cm or 99.8%Nitrogen water (NH·H20)0.90g/cm3～0.91g/cm or 25%~28%In chemical analysis, the acid or ammonia water used, if the concentration is not specified, refers to the commercially available concentrated acid or concentrated ammonia water. The dilution degree of the reagent is expressed by volume ratio, for example: hydrochloric acid (1+2) means: 1 volume of concentrated hydrochloric acid is mixed with 2 volumes of water. 4.1 Sodium hydroxide (NaOH).
4.2 Potassium hydroxide (KOH).
4.3 Potassium chloride (KCI): When the particles are coarse, they should be ground into powder before use. 4.4 Potassium pyrosulfate (K,S2O,): Heat and melt commercially available potassium pyrosulfate in porcelain evaporating blood. After bubbles stop forming, cool, grind, and store in a ground-mouth bottle.
4.5 Hydrochloric acid (1+1); (1+2); (1+5).
4.6 Sulfuric acid (1+1)(1+9).
4.7 Water (1+1); (1+2).
4.8 Silver nitrate solution (10g/L): Dissolve 1g of silver nitrate (AgNO) in 90mL of water, add 10mL of nitric acid (HNO), shake well, and store in a brown dropper bottle.
4.9 Barium chloride solution (100g/L): Dissolve 100g of barium nitride dihydrate (BaCl·2H,0) in water and dilute to 1L with water. 4.10 Triethanolamine [N(CHCH,OH)]: (1+2). 4.11 Potassium hydroxide solution (200g/L): Dissolve 200g potassium hydroxide (KOH) in water and dilute to 1L with water. Store in a plastic bottle.
4.12 Potassium sodium tartrate solution (100g/L): Dissolve 100g potassium sodium tartrate (C,H,KNaO.·4H20) in water and dilute to 1L. 4.13 Ascorbic acid solution (10g/L): Dissolve 1g ascorbic acid (CHO.) in 100mL water, filter and use, prepare freshly when used. O-phenanthroline solution (10g/L): Dissolve 1g o-phenanthroline (C2HgN2·H0) in 100mL acetic acid (1+1), prepare freshly when used. 4.14
5 Ammonium acetate solution (100g/L): Dissolve 10g ammonium acetate (CH.COONH) in 100mL water. 4.15
EDTA-Cu solution: According to the volume ratio (see 4.31.2) of [c(EDTA）=0.015mol/L]EDTA standard titration solution (see 4.30) and [c(CuSO,）=4.16
0.015mol/L copper sulfate standard titration solution (see 4.31), accurately prepare a mixed solution of equal concentration. 4.17 pH 3.0 buffer solution: Dissolve 3.2g anhydrous sodium acetate (CH.COONa) in water, add 120mL glacial acetic acid (CH,COOH), dilute to 1L with water, and shake well. 4.18 pH 4.3 buffer solution: Dissolve 42.3g anhydrous sodium acetate (CHCOONa) in water, add 80mL glacial acetic acid (CH.COOH), dilute to 1L with water, and shake well. 4.19 pH 10 buffer solution: Dissolve 67.5g ammonium fluoride (NH,CI) in water, add 570mL ammonia water (NH;·H,O), and dilute with water by 2
to 1L.
GB/T 5484—2000
4.20 Diantipyrine methane solution (30g/L hydrochloric acid solution): Dissolve 15g diantipyrine methane (C23H24N,O.) in 500mL hydrochloric acid (1+11), filter and use.
4.21 Ammonium carbonate solution (100g/L): Dissolve 10g ammonium carbonate [(NH)2CO] in 100mL water, prepare it when used. 4.22 Potassium fluoride solution (150 g/L): Weigh 150 g potassium fluoride (KF·2H,0) into a plastic cup, add water to dissolve, dilute with water to 1 L, and store in a plastic bottle.
4.23 Potassium chloride solution (50 g/L): Dissolve 50 g potassium fluoride (KCI) in water, dilute with water to 1 L. 4.24 Potassium chloride-ethanol solution (50 g/L): Dissolve 5 g potassium chloride (KCI) in 50 mL water, add 50 mL of 95% (V/V) ethanol (C,H,OH), and mix well.
4.25 Sodium hydroxide solution (80 g/L): Dissolve 80 g sodium hydroxide in water, dilute with water to 1 L, and store in a plastic bottle. 4.26 Total ionic strength coordination buffer of pH 6.0: Dissolve 294.1g sodium citrate (C.HNa0,·2H.O) in water, adjust the solution pH to 6.0 with hydrochloric acid (1 + 1) and sodium hydroxide solution (see 4.25), then dilute to 1L with water and shake. 4.27 Extract (also known as organic phase): Mix 1 volume of n-butanol with 3 volumes of chloroform and shake well. 4.28 Ammonium molybdate solution (50g/L): Dissolve 5g of ammonium molybdate solution [(NH)Mo,O24·4H,O] in water, dilute to 100mL with water, filter and store in a plastic bottle. This solution can be stored for about one week. 4.29 Calcium carbonate standard solution [c(CaCO3)=0.024mol/L] Weigh about 0.6g (m,) calcium carbonate (CaCO) that has been dried at 105℃~110℃ for 2h, accurate to 0.0001g, place in a 400mL beaker, add about 100mL water, cover with a surface NM, drip hydrochloric acid (1+1) along the mouth of the beaker until the calcium carbonate is completely dissolved, heat and boil for several minutes. Cool the solution to room temperature, transfer to a 250mL volumetric flask, dilute with water to the mark, and shake well. 4.30 EDTA standard titration solution [c(EDTA)=0.015mol/L] 4.30.1 Preparation of standard titration solution
Weigh about 5.6g EDTA (disodium salt of ethylenediaminetetraacetic acid) and place in a beaker, add about 200mL water, heat to dissolve, filter, and dilute with water to 1L.
4.30.2 Calibration of the concentration of EDTA standard titration solution Pipette 25.00mL of calcium carbonate standard solution (see 4.29) into a 400mL beaker, dilute with water to about 200mL, add an appropriate amount of CMP mixed indicator (see 4.41), add potassium hydroxide solution (see 4.11) under stirring until green fluorescence appears, then add 2mL~3mL in excess, and titrate with EDTA standard titration solution until the green fluorescence disappears and red appears. The concentration of the EDTA standard titration solution is calculated according to formula (1): C(EDTA)=
m×25×1000
250×V,×100.09
Wherein: c(EDTA)——concentration of the EDTA standard titration solution, mol/L; m
V,—volume of the EDTA standard titration solution consumed during titration, mL; 1
m—mass of calcium carbonate prepared according to 4.29 for the calcium carbonate standard solution, g; 100.09—molar mass of CaCO, g/mol. 4.30.3 Calculation of the titration degree of EDTA standard titration solution for each oxide (1) The titration degree of EDTA standard titration solution for ferric oxide, aluminum oxide, calcium oxide and magnesium oxide is calculated according to formula (2), (3), (4) and (5) respectively:
TFe,0,=c(EDTA)X 79.84
TAl,0, =c(EDTA) × 50.98
Tc0 =c(EDTA) X 56.08
TM0=c(EDTA)X40.31
Wherein: TFe,0,——The mass of ferric oxide per milliliter of EDTA standard titration solution, mg/mL; (2)
·(3)
(4)
(5)
GB/T5484--2000
The mass of aluminum oxide per milliliter of EDTA standard titration solution, mg/mL; -The mass of calcium oxide per milliliter of EDTA standard titration solution, mg/mL Amount, mg/mL; Tcao
TMo—The mass of magnesium oxide equivalent to each milliliter of EDTA standard titration solution, mg/mL; c(EDTA)—Concentration of EDTA standard titration solution, mol/L; 79.84--=-The molar mass of (1/2Fe20), g/mol; the molar mass of (1/2Al20), g/mol; 50.98-
~The molar mass of CaO, g/mol;
40.31The molar mass of Mg0, g/mol.
4.31Copper sulfate standard titration solution Lc(CuSO,)=0.015mol/L] 4.31.1 Preparation of standard titration solution
Dissolve 3.7g of copper sulfate (CuSO,·5H,0) in water, add 4 to 5 drops of sulfuric acid (1+1), dilute to 1L with water, and shake well. 4.31.2 Calibration of the volume ratio of EDTA standard titration solution to copper sulfate standard titration solution Slowly release 10mL~15mL [c(EDTA)=0.015mol/L EDTA standard titration solution (see 4.30) from the burette into a 400mL beaker, dilute with water to about 150mL, add 15mL of pH4.3 buffer solution (see 4.18), heat to boiling, take out and cool slightly, add 5 to 6 drops of PAN indicator solution (see 4.40), and titrate with copper sulfate standard titration solution until bright purple. The volume ratio of EDTA standard titration solution to copper sulfate standard titration solution is calculated according to formula (6): V
Where: K—the volume of EDTA standard titration solution per milliliter of copper sulfate standard titration solution; V2—the volume of EDTA standard titration solution, mL; V3—the volume of copper sulfate standard titration solution consumed during titration, mL. 4.32 Standard titration solution of sodium hydroxide [c(NaOH)=0.15mol/L] 4.32.1 Preparation of standard titration solution
(6)
Dissolve 60g of sodium hydroxide (NaOH) in 10L of water, shake thoroughly, and store in a hard glass bottle or plastic bottle with a rubber stopper (with soda lime in a drying tube).
4.32.2 Calibration of the concentration of standard titration solution of sodium hydroxide Weigh about 0.8g (m) potassium hydrogen phthalate (CgHsKO,) with an accuracy of 0.0001g, put it in a 400mL beaker, add about 150mL of freshly boiled cold water that has been neutralized with sodium hydroxide solution until the phenol turns slightly red, stir to dissolve it, add 6 to 7 drops of phenolphthalein indicator solution (see 4.43), and titrate with sodium hydroxide standard titration solution until it turns slightly red. The concentration of sodium hydroxide standard titration solution is calculated according to formula (7): c(NaOH)
wherein: c(NaOH)
mz×1000
-concentration of sodium hydroxide standard titration solution, mol/L;-volume of sodium hydroxide standard titration solution consumed during titration, mL; mass of potassium hydrogen phthalate, g;
-molar mass of potassium hydrogen phthalate, g/mol. 4.32.3 The titration degree of sodium hydroxide standard titration solution on silicon dioxide is calculated according to formula (8): Tso, = c(NaOH) × 15. 02
Wherein: Tso,
c(NaOH)
The mass of silicon dioxide per milliliter of sodium hydroxide standard titration solution, mg/mL; The concentration of sodium hydroxide standard titration solution, mol/L; The molar mass of (1/4SiO,), g/mol. 4.33 Ferric oxide (Fe2O3) standard solution 4.33.1 Preparation of standard solution wwW.bzxz.Net
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GB/T5484—2000
Weigh 0.1000g of ferric oxide (Fe2O3) that has been calcined at 950℃ for 1h, accurate to 0.0001g, and place it in a 300mL beaker. Add 50mL of water, 30mL of hydrochloric acid (1+1), and 2mL of nitric acid in sequence. Heat at low temperature until all dissolved, cool to room temperature, transfer to a 1000mL volumetric flask, dilute with water to the mark, and shake well. This standard solution contains 0.1mg of ferric oxide per milliliter. 4.33.2 Drawing of working curve
Put 0, 1.00mL, 2.00mL, 3.00mL, 4.00mL, 5.00mL, and 6.00mL of the standard solution containing 0.1mg ferric oxide per mL into 100mL volumetric flasks, dilute to about 50mL with water, add 5mL ascorbic acid (see 4.13), let stand for 5min, then add 5mL o-phenanthroline solution (see 4.14) and 10mL ammonium acetate solution (see 4.15), dilute to the mark with water, and shake well. After standing for 30min, use a spectrophotometer, a 10mm cuvette, and water as a reference to measure the absorbance of the solution at 510nm. Use the measured absorbance as the function of the corresponding ferric oxide content to draw the working curve. 4.34 Potassium oxide (KO) and sodium oxide (Na2O) standard solutions 4.34.1 Preparation of potassium oxide standard solution
Weigh 0.7915 g of potassium chloride (KCl) that has been dried at 130℃~150℃ for 2 hours, accurately to 0.0001 g, place in a beaker, add water to dissolve, transfer to a 1000 mL volumetric flask, dilute with water to the mark, and shake well. Store in a plastic bottle. Each milliliter of this standard solution is equivalent to 0.5 mg of potassium oxide.
4.34.2 Preparation of sodium oxide standard solution
Weigh 0.9430 g of sodium chloride (NaCl) that has been dried at 130℃~150℃ for 2 hours, accurately to 0.0001 g, place in a beaker, add water to dissolve, transfer to a 1000 mL volumetric flask, dilute with water to the mark, and shake well. Stored in a plastic bottle, this standard solution is equivalent to 0.5 mg sodium oxide per milliliter.
4.34.3 Drawing of working curve
Put 0, 1.00 mL, 2.00 mL, 4.00 mL, 6.00 mL, 8.00 mL, 10.00 mL, 12.00 mL of the standard solution prepared according to (4.34.1) that is equivalent to 0.5 mg potassium oxide per milliliter and 0, 1.00 mL, 2.00 mL, 4.00 mL, 6.00 mL, 8.00 mL, 10.00 mL, 12.00 mL of the standard solution prepared according to (4.34.2) that is equivalent to 0.5 mg sodium oxide per milliliter, respectively, in a corresponding order, into a 100 mL volumetric flask, dilute with water to the mark, and shake well. Use a flame photometer to measure according to the instrument usage regulations. Use the measured galvanometer readings as a function of the corresponding potassium oxide and sodium oxide content to draw a working curve. 4.35 Fluorine (F-) standard solution
4.35.1 Preparation of standard solution
Weigh 0.2763g of high-grade pure sodium fluoride (NaF) to an accuracy of 0.0001g, place it in a platinum crucible, burn it at about 500℃ for 10min (or bake it at 120℃ for 2h), place it in a beaker, add water to dissolve it, transfer it to a 500mL volumetric flask, dilute it with water to the mark, shake it well, and store it in a plastic bottle. This standard solution is equivalent to 0.25mg fluorine per milliliter. Take 2.00mL, 10.00mL, and 20.00mL of the above standard solution and place them in 500mL volumetric flasks respectively, add water to dilute it into a series of standard solutions equivalent to 0.001mg, 0.005mg, and 0.010mg fluorine per milliliter, and store them in plastic bottles respectively. 4.35.2 Drawing of working curve
Pick 10.00mL of each series of standard solutions (4.35.1) and put them into a 50mL beaker with a stirring bar. Add 10.00mL of total ionic strength coordination buffer solution (see 4.26) of pH 6.0. Place the beaker on an electromagnetic stirrer (see 5.7). Insert a fluoride ion selective electrode and a saturated potassium nitride calomel electrode (see 5.10) into the solution. Turn on the magnetic stirrer and stir for 2min, then stop stirring for 30s. Then measure the equilibrium potential of the solution with an ion meter or acidity meter. Use single logarithmic coordinate paper, with the logarithmic coordinate as the fluorine concentration and the constant coordinate as the potential value, to draw the working curve.
4.36 Phosphorus pentoxide (P,0s) standard solution 4.36.1 Preparation of standard solution
Weigh 1.9170g potassium dihydrogen phosphate (KH,P0,) that has been dried at 105℃～110℃ for 2h, accurate to 0.0001g, put it in a 300mL beaker, add water to dissolve, transfer to a 1000mL volumetric flask, dilute with water to the mark, and shake well. This standard solution is equivalent to 1.0mg phosphorus pentoxide per milliliter.
Pipette 50.00mL of the above standard solution into a 1000mL volumetric flask, dilute with water to the mark, and shake well. This standard solution is equivalent to 0.05mg phosphorus pentoxide per milliliter.
4.36.2 Working curve
GB/T5484—2000
Pipette 1.00mL, 2.00mL, 3.00mL, and 4.00mL of the standard solution containing 0.05mg of phosphorus pentoxide per mL into four separating funnels that have absorbed 9.00mL, 8.00mL, 7.00mL, and 6.00mL of water, respectively, and add 5mL of nitric acid (1+1), transfer 15.00mL of the extract (see 4.27), and 5mL of ammonium molybdate (see 4.28), plug the funnel, shake vigorously for 2min3min, and let it stand to separate. Then carefully remove the plug to reduce the pressure in the funnel, release a small amount of organic phase to wash the inner wall of the funnel, and then put the organic phase into a 50mL dry beaker and cover it with surface III. Use a spectrophotometer with 10 mm colorimetric blood, take the extract (see 4.27) as a reference, and measure the absorbance of the solution at a wavelength of 420 nm. Use the measured absorbance as a function of the corresponding phosphorus pentoxide content to draw a working curve. 4.37 Titanium dioxide (TiO2) standard solution
4.37.1 Preparation of standard solution
Weigh 0.1000 g of titanium dioxide (TiO2) calcined at high temperature to an accuracy of 0.0001 g, place it in a platinum (or porcelain) crucible, add 2 g of potassium pyrosulfate (see 4.4), and melt at 500℃～600℃ until transparent. The frit is leached with sulfuric acid (1+9), heated to 50℃～60℃ to completely dissolve the frit, and after cooling, transfer it to a 1000 mL volumetric flask, dilute to the mark with sulfuric acid (1+9), and shake well. This standard solution contains 0.1 mg titanium dioxide per milliliter.
Put 100.00mL of the above standard solution in a 500mL volumetric flask, dilute to the mark with sulfuric acid (1+9), and shake well. This standard solution contains 0.02mg titanium dioxide per milliliter.
4.37.2 Drawing of working curve
Put 0, 2.00mL, 4.00mL, 6.00mL, 8.00mL, 10.00mL, and 12.00mL of the standard solution containing 0.02mg titanium dioxide per milliliter in a 100mL volumetric flask, and add 10mL of hydrochloric acid (1+2), 10mL of ascorbic acid solution (see 4.13), 5mL of 95% (V/V) ethanol, and 20mL of diantipyrine methane solution (see 4.20), dilute with water to the mark, shake well. After standing for 40 minutes, use a spectrophotometer, 10mm cuvette, and water as a reference to measure the absorbance of the solution at 420nm. Use the measured absorbance as a function of the corresponding titanium dioxide content to draw a working curve. 4.38 Methyl red indicator solution (2g/L): Dissolve 0.2g methyl red in 100mL 95% (V/V) ethanol. 4.39 Sodium sulfosalicylate indicator solution (100g/L): Dissolve 10g sodium sulfosalicylate in water and dilute to 100mL with water. 4.40
1(2-pyridylazo)-2-naphthol (PAN) indicator solution (2g/L): Dissolve 0.2g PAN in 100mL 95% (V/V) ethanol.
Calcium chlorophyll-methyl thymol blue-phenolphthalein mixed indicator (referred to as CMP mixed indicator): weigh 1.000g of calcein, 4.41
1.000 polymethyl thymol blue, 0.200g of phenolphthalein and 50g of potassium nitrate (KNO) dried at 105℃, mix and grind, and store in a ground-mouth bottle.
4.42 Acid chrome blue K-naphthol green B mixed indicator: weigh 1.000g of acid chrome blue K, 2.5g of phenol green B and 50g of potassium nitrate (KNO) dried at 105℃, mix and grind, and store in a ground-mouth bottle. 4.43 Phenolic acid indicator solution (10g/L): dissolve 1g of phenolic acid in 100mL of 95% (V/V) ethanol. 4.44 Bromophenol blue indicator solution (2g/L): Dissolve 0.2g bromophenol blue in 100mL ethanol (1+4). 5 Instruments and equipment
5.1 Balance, not less than level 4, accurate to 0.0001g. 5.2 Silver (platinum) or porcelain crucible: with cover, capacity 15mL~30mL. 5.3 Platinum blood: capacity 50mL~100mL.
5.4 Muffle furnace: a flame-muffle heating furnace, with resistance heating on the periphery of the furnace. A temperature controller should be used to accurately control the furnace temperature and calibrate it regularly.
Filter paper: three types of ash-free fast, medium and slow quantitative filter paper. 5.6 Material
Glass volumetric vessels burette, volumetric flask, pipette, weighing bottle. 5.7 Magnetic stirrer: a stirrer with a plastic shell, equipped with a speed control device. 6
GB/T5484~2000
5:8 Spectrophotometer: can measure the absorbance of the solution in the range of 400nm~700nm, with 10mm and 20mm cuvettes. 5.9 Flame photometer: with 768nm and 589nm interference filters. 5.10 Ion meter or acidity meter: with fluoride ion selective electrode and saturated potassium chloride calomel electrode. 6 Preparation of samples
Sampling should be carried out according to the method of GB/T2007.1. The samples sent to the laboratory should be representative and uniform samples. Use the quartering method to reduce to about 100g, sieve through a 0.080mm square hole sieve, use a magnet to absorb the metallic iron in the sieve residue, grind the sieve residue to make it pass through the 0.080mm square hole sieve. After the sample is fully mixed, put it into a bottle with a ground stopper and seal it. 7 Determination of adhering water (standard method)
7.1 Analysis steps
Weigh about 1g of sample (ma), accurate to 0.0001g, and put it into a weighing bottle with a ground-mouth stopper that has been dried to a constant weight, and dry it in an oven at 45℃±3℃ for 1h (the weighing bottle should be loosened during the drying process), take it out, cover it with a ground-mouth stopper (but not too tightly), and put it in a desiccator to cool to room temperature. Cover the ground-mouth stopper tightly and weigh it. Then put the weighing bottle in the oven with the cover loosened, and dry it at the same temperature for 30min. Repeat the drying, cooling, and weighing until the constant weight is obtained. 7.2 Result expression
The mass percentage of adhering water X is calculated according to formula (9): ms - mt × 100
Where: X,-mass percentage of adhering water, %; mass of the sample before drying, g;
m4-mass of the sample after drying, g.
7.3 Allowable error
The allowable error for the same laboratory is 0.20%.
8 Determination of crystal water (standard method)
8.1 Analytical steps
(9)
Weigh about 1g of sample (ms) to an accuracy of 0.0001g, put it into a weighing bottle with a ground-mouth stopper that has been dried and has a constant weight, heat it in an oven at 230℃±5℃ for 1h, take out the weighing bottle with tongs, cover it with a ground-mouth stopper, put it in a desiccator to cool to room temperature, and weigh it. Then put it in an oven and heat it at the same temperature for 30min, repeat heating, cooling, and weighing until the constant weight is reached. 8.2 Result expression
The mass percentage of crystal water X2 is calculated according to formula (10): Xz= ms= me × 100 - X
Wherein: X, —-mass percentage of crystal water, %; ms—mass of sample before heating, g;
mg—mass of sample after heating, g;
X, —-mass percentage of attached water measured according to 7.2, %. 8.3 Allowable difference
The allowable difference for the same laboratory is 0.15%;
The allowable difference for different laboratories is 0.20%.
(10)
9 Determination of acid-insoluble matter (standard method)
9.1 Analytical steps
GB/T5484—2000
Weigh about 0.5g of sample (mt), accurate to 0.0001g, place in a 250mL beaker, moisten with water and cover with blood. Slowly add 40mL of hydrochloric acid (1+5) from the mouth of the beaker. After the reaction stops, rinse the surface III and the wall of the beaker with water and dilute to about 75mL. Heat and boil for 3min~4min, filter with slow filter paper, wash with hot water until there is no chloride ion (see 3.6). Transfer the residue and filter paper to a calcined and constant-weight porcelain crucible. Ash, calcine at 950℃~1000℃ for 20min, take out, put in a desiccator, cool to room temperature, and weigh. Repeat calcination, cooling, and weighing until constant weight is achieved. 9.2 Result Expression
The mass percentage X of acid insoluble matter is calculated according to formula (11): Xg = m ×100
Wherein: X3—mass percentage of acid insoluble matter, %; mg—mass of residue after ignition, g,
—mass of sample, g.
9.3 Allowable Difference
The allowable difference in the same laboratory is 0.15%;
The allowable difference in different laboratories is 0.20%.
10 Determination of Sulfur Trioxide (Standard Method)
10.1 Summary of Method
(11)
In an acidic solution, sulfate is precipitated with barium chloride solution, filtered and ignited, and weighed in the form of barium sulfate. The determination result is calculated as sulfur trioxide.
10.2 Analysis steps
Weigh about 0.2g of sample (mg), accurate to 0.0001g, place in a 300mL beaker, add 30mL40mL water to disperse it. Add 10mL hydrochloric acid (1+1), crush the lumps with a flat glass rod, and slowly heat the solution until the sample is completely decomposed. Heat the solution to a slight boil for 5min. Filter with medium-speed filter paper and wash with hot water 10~12 times. Adjust the volume of the filtrate to 200mL, boil, add 15mL of barium chloride solution (see 4.9) dropwise while stirring, continue boiling for several minutes, then move to a warm place and let stand for 4h or overnight (the volume of the solution should be kept at 200mL at this time). Filter with slow filter paper and wash with warm water until it is tested to be free of nitrogen ions (see 3.6). Transfer the precipitate and filter paper to the porcelain that has been burned to a constant weight. After ashing, burn in a muffle furnace at 800℃ (see 5.4) for 30 minutes. Take out the crucible and place it in a desiccator to cool to room temperature and weigh it. Repeat the burning until the weight is constant. 10.3 Result expression
The mass percentage of sulfur trioxide Xso is calculated according to formula (12): Xxs, X0. 343 × 100
Where: Xso,
The mass percentage of sulfur trioxide, %;
The mass of the precipitate after burning, g;
The mass of the sample, g;
0.343——The conversion coefficient of sulfur trioxide to sulfur trioxide. 10.4 Allowable difference
The allowable difference of the same laboratory is 0.25%:
The allowable difference of different laboratories is 0.40%.
（12）2g PAN is dissolved in 100mL 95% (V/V) ethanol.
Calcium chlorophyll-methyl thymol blue-phenolphthalein mixed indicator (referred to as CMP mixed indicator): weigh 1.000g calcein, 4.41
1.000 polymethyl thymol blue, 0.200g phenolphthalein and 50g potassium nitrate (KNO) dried at 105℃, mix and grind, and store in a ground-mouth bottle.
4.42 Acid chrome blue K-naphthol green B mixed indicator: weigh 1.000g acid chrome blue K, 2.5g phenol green B and 50g potassium nitrate (KNO) dried at 105℃, mix and grind, and store in a ground-mouth bottle. 4.43 Phenolic acid indicator solution (10g/L): dissolve 1g phenolic acid in 100mL 95% (V/V) ethanol. 4.44 Bromophenol blue indicator solution (2g/L): Dissolve 0.2g bromophenol blue in 100mL ethanol (1+4). 5 Instruments and equipment
5.1 Balance, not less than level 4, accurate to 0.0001g. 5.2 Silver (platinum) or porcelain crucible: with cover, capacity 15mL~30mL. 5.3 Platinum blood: capacity 50mL~100mL.
5.4 Muffle furnace: a flame-muffle heating furnace, with resistance heating on the periphery of the furnace. A temperature controller should be used to accurately control the furnace temperature and calibrate it regularly.
Filter paper: three types of ash-free fast, medium and slow quantitative filter paper. 5.6 Material
Glass volumetric vessels burette, volumetric flask, pipette, weighing bottle. 5.7 Magnetic stirrer: a stirrer with a plastic shell, equipped with a speed control device. 6
GB/T5484~2000
5:8 Spectrophotometer: can measure the absorbance of the solution in the range of 400nm~700nm, with 10mm and 20mm cuvettes. 5.9 Flame photometer: with 768nm and 589nm interference filters. 5.10 Ion meter or acidity meter: with fluoride ion selective electrode and saturated potassium chloride calomel electrode. 6 Preparation of samples
Sampling should be carried out according to the method of GB/T2007.1. The samples sent to the laboratory should be representative and uniform samples. Use the quartering method to reduce to about 100g, sieve through a 0.080mm square hole sieve, use a magnet to absorb the metallic iron in the sieve residue, grind the sieve residue to make it pass through the 0.080mm square hole sieve. After the sample is fully mixed, put it into a bottle with a ground stopper and seal it. 7 Determination of adhering water (standard method)
7.1 Analysis steps
Weigh about 1g of sample (ma), accurate to 0.0001g, and put it into a weighing bottle with a ground-mouth stopper that has been dried to a constant weight, and dry it in an oven at 45℃±3℃ for 1h (the weighing bottle should be loosened during the drying process), take it out, cover it with a ground-mouth stopper (but not too tightly), and put it in a desiccator to cool to room temperature. Cover the ground-mouth stopper tightly and weigh it. Then put the weighing bottle in the oven with the cover loosened, and dry it at the same temperature for 30min. Repeat the drying, cooling, and weighing until the constant weight is obtained. 7.2 Result expression
The mass percentage of adhering water X is calculated according to formula (9): ms - mt × 100
Where: X,-mass percentage of adhering water, %; mass of the sample before drying, g;
m4-mass of the sample after drying, g.
7.3 Allowable error
The allowable error for the same laboratory is 0.20%.
8 Determination of crystal water (standard method)
8.1 Analytical steps
(9)
Weigh about 1g of sample (ms) to an accuracy of 0.0001g, put it into a weighing bottle with a ground-mouth stopper that has been dried and has a constant weight, heat it in an oven at 230℃±5℃ for 1h, take out the weighing bottle with tongs, cover it with a ground-mouth stopper, put it in a desiccator to cool to room temperature, and weigh it. Then put it in an oven and heat it at the same temperature for 30min, repeat heating, cooling, and weighing until the constant weight is reached. 8.2 Result expression
The mass percentage of crystal water X2 is calculated according to formula (10): Xz= ms= me × 100 - X
Wherein: X, —-mass percentage of crystal water, %; ms—mass of sample before heating, g;
mg—mass of sample after heating, g;
X, —-mass percentage of attached water measured according to 7.2, %. 8.3 Allowable difference
The allowable difference for the same laboratory is 0.15%;
The allowable difference for different laboratories is 0.20%.
(10)
9 Determination of acid-insoluble matter (standard method)
9.1 Analytical steps
GB/T5484—2000
Weigh about 0.5g of sample (mt), accurate to 0.0001g, place in a 250mL beaker, moisten with water and cover with blood. Slowly add 40mL of hydrochloric acid (1+5) from the mouth of the beaker. After the reaction stops, rinse the surface III and the wall of the beaker with water and dilute to about 75mL. Heat and boil for 3min~4min, filter with slow filter paper, wash with hot water until there is no chloride ion (see 3.6). Transfer the residue and filter paper to a calcined and constant-weight porcelain crucible. Ash, calcine at 950℃~1000℃ for 20min, take out, put in a desiccator, cool to room temperature, and weigh. Repeat calcination, cooling, and weighing until constant weight is achieved. 9.2 Result Expression
The mass percentage X of acid insoluble matter is calculated according to formula (11): Xg = m ×100
Wherein: X3—mass percentage of acid insoluble matter, %; mg—mass of residue after ignition, g,
—mass of sample, g.
9.3 Allowable Difference
The allowable difference in the same laboratory is 0.15%;
The allowable difference in different laboratories is 0.20%.
10 Determination of Sulfur Trioxide (Standard Method)
10.1 Summary of Method
(11)
In an acidic solution, sulfate is precipitated with barium chloride solution, filtered and ignited, and weighed in the form of barium sulfate. The determination result is calculated as sulfur trioxide.
10.2 Analysis steps
Weigh about 0.2g of sample (mg), accurate to 0.0001g, place in a 300mL beaker, add 30mL40mL water to disperse it. Add 10mL hydrochloric acid (1+1), crush the lumps with a flat glass rod, and slowly heat the solution until the sample is completely decomposed. Heat the solution to a slight boil for 5min. Filter with medium-speed filter paper and wash with hot water 10~12 times. Adjust the volume of the filtrate to 200mL, boil, add 15mL of barium chloride solution (see 4.9) dropwise while stirring, continue boiling for several minutes, then move to a warm place and let stand for 4h or overnight (the volume of the solution should be kept at 200mL at this time). Filter with slow filter paper and wash with warm water until it is tested to be free of nitrogen ions (see 3.6). Transfer the precipitate and filter paper to the porcelain that has been burned to a constant weight. After ashing, burn in a muffle furnace at 800℃ (see 5.4) for 30 minutes. Take out the crucible and place it in a desiccator to cool to room temperature and weigh it. Repeat the burning until the weight is constant. 10.3 Result expression
The mass percentage of sulfur trioxide Xso is calculated according to formula (12): Xxs, X0. 343 × 100
Where: Xso,
The mass percentage of sulfur trioxide, %;
The mass of the precipitate after burning, g;
The mass of the sample, g;
0.343——The conversion coefficient of sulfur trioxide to sulfur trioxide. 10.4 Allowable difference
The allowable difference of the same laboratory is 0.25%:
The allowable difference of different laboratories is 0.40%.
（12）2g PAN is dissolved in 100mL 95% (V/V) ethanol.
Calcium chlorophyll-methyl thymol blue-phenolphthalein mixed indicator (referred to as CMP mixed indicator): weigh 1.000g calcein, 4.41
1.000 polymethyl thymol blue, 0.200g phenolphthalein and 50g potassium nitrate (KNO) dried at 105℃, mix and grind, and store in a ground-mouth bottle.
4.42 Acid chrome blue K-naphthol green B mixed indicator: weigh 1.000g acid chrome blue K, 2.5g phenol green B and 50g potassium nitrate (KNO) dried at 105℃, mix and grind, and store in a ground-mouth bottle. 4.43 Phenolic acid indicator solution (10g/L): dissolve 1g phenolic acid in 100mL 95% (V/V) ethanol. 4.44 Bromophenol blue indicator solution (2g/L): Dissolve 0.2g bromophenol blue in 100mL ethanol (1+4). 5 Instruments and equipment
5.1 Balance, not less than level 4, accurate to 0.0001g. 5.2 Silver (platinum) or porcelain crucible: with cover, capacity 15mL~30mL. 5.3 Platinum blood: capacity 50mL~100mL.
5.4 Muffle furnace: a flame-muffle heating furnace, with resistance heating on the periphery of the furnace. A temperature controller should be used to accurately control the furnace temperature and calibrate it regularly.
Filter paper: three types of ash-free fast, medium and slow quantitative filter paper. 5.6 Material
Glass volumetric vessels burette, volumetric flask, pipette, weighing bottle. 5.7 Magnetic stirrer: a stirrer with a plastic shell, equipped with a speed control device. 6
GB/T5484~2000
5:8 Spectrophotometer: can measure the absorbance of the solution in the range of 400nm~700nm, with 10mm and 20mm cuvettes. 5.9 Flame photometer: with 768nm and 589nm interference filters. 5.10 Ion meter or acidity meter: with fluoride ion selective electrode and saturated potassium chloride calomel electrode. 6 Preparation of samples
Sampling should be carried out according to the method of GB/T2007.1. The samples sent to the laboratory should be representative and uniform samples. Use the quartering method to reduce to about 100g, sieve through a 0.080mm square hole sieve, use a magnet to absorb the metallic iron in the sieve residue, grind the sieve residue to make it pass through the 0.080mm square hole sieve. After the sample is fully mixed, put it into a bottle with a ground stopper and seal it. 7 Determination of adhering water (standard method)
7.1 Analysis steps
Weigh about 1g of sample (ma), accurate to 0.0001g, and put it into a weighing bottle with a ground-mouth stopper that has been dried to a constant weight, and dry it in an oven at 45℃±3℃ for 1h (the weighing bottle should be loosened during the drying process), take it out, cover it with a ground-mouth stopper (but not too tightly), and put it in a desiccator to cool to room temperature. Cover the ground-mouth stopper tightly and weigh it. Then put the weighing bottle in the oven with the cover loosened, and dry it at the same temperature for 30min. Repeat the drying, cooling, and weighing until the constant weight is obtained. 7.2 Result expression
The mass percentage of adhering water X is calculated according to formula (9): ms - mt × 100
Where: X,-mass percentage of adhering water, %; mass of the sample before drying, g;
m4-mass of the sample after drying, g.
7.3 Allowable error
The allowable error for the same laboratory is 0.20%.
8 Determination of crystal water (standard method)
8.1 Analytical steps
(9)
Weigh about 1g of sample (ms) to an accuracy of 0.0001g, put it into a weighing bottle with a ground-mouth stopper that has been dried and has a constant weight, heat it in an oven at 230℃±5℃ for 1h, take out the weighing bottle with tongs, cover it with a ground-mouth stopper, put it in a desiccator to cool to room temperature, and weigh it. Then put it in an oven and heat it at the same temperature for 30min, repeat heating, cooling, and weighing until the constant weight is reached. 8.2 Result expression
The mass percentage of crystal water X2 is calculated according to formula (10): Xz= ms= me × 100 - X
Wherein: X, —-mass percentage of crystal water, %; ms—mass of sample before heating, g;
mg—mass of sample after heating, g;
X, —-mass percentage of attached water measured according to 7.2, %. 8.3 Allowable difference
The allowable difference for the same laboratory is 0.15%;
The allowable difference for different laboratories is 0.20%.
(10)
9 Determination of acid-insoluble matter (standard method)
9.1 Analytical steps
GB/T5484—2000
Weigh about 0.5g of sample (mt), accurate to 0.0001g, place in a 250mL beaker, moisten with water and cover with blood. Slowly add 40mL of hydrochloric acid (1+5) from the mouth of the beaker. After the reaction stops, rinse the surface III and the wall of the beaker with water and dilute to about 75mL. Heat and boil for 3min~4min, filter with slow filter paper, wash with hot water until there is no chloride ion (see 3.6). Transfer the residue and filter paper to a calcined and constant-weight porcelain crucible. Ash, calcine at 950℃~1000℃ for 20min, take out, put in a desiccator, cool to room temperature, and weigh. Repeat calcination, cooling, and weighing until constant weight is achieved. 9.2 Result Expression
The mass percentage X of acid insoluble matter is calculated according to formula (11): Xg = m ×100
Wherein: X3—mass percentage of acid insoluble matter, %; mg—mass of residue after ignition, g,
—mass of sample, g.
9.3 Allowable Difference
The allowable difference in the same laboratory is 0.15%;
The allowable difference in different laboratories is 0.20%.
10 Determination of Sulfur Trioxide (Standard Method)
10.1 Summary of Method
(11)
In an acidic solution, sulfate is precipitated with barium chloride solution, filtered and ignited, and weighed in the form of barium sulfate. The determination result is calculated as sulfur trioxide.
10.2 Analysis steps
Weigh about 0.2g of sample (mg), accurate to 0.0001g, place in a 300mL beaker, add 30mL40mL water to disperse it. Add 10mL hydrochloric acid (1+1), crush the lumps with a flat glass rod, and slowly heat the solution until the sample is completely decomposed. Heat the solution to a slight boil for 5min. Filter with medium-speed filter paper and wash with hot water 10~12 times. Adjust the volume of the filtrate to 200mL, boil, add 15mL of barium chloride solution (see 4.9) dropwise while stirring, continue boiling for several minutes, then move to a warm place and let stand for 4h or overnight (the volume of the solution should be kept at 200mL at this time). Filter with slow filter paper and wash with warm water until it is tested to be free of nitrogen ions (see 3.6). Transfer the precipitate and filter paper to the porcelain that has been burned to a constant weight. After ashing, burn in a muffle furnace at 800℃ (see 5.4) for 30 minutes. Take out the crucible and place it in a desiccator to cool to room temperature and weigh it. Repeat the burning until the weight is constant. 10.3 Result expression
The mass percentage of sulfur trioxide Xso is calculated according to formula (12): Xxs, X0. 343 × 100
Where: Xso,
The mass percentage of sulfur trioxide, %;
The mass of the precipitate after burning, g;
The mass of the sample, g;
0.343——The conversion coefficient of sulfur trioxide to sulfur trioxide. 10.4 Allowable difference
The allowable difference of the same laboratory is 0.25%:
The allowable difference of different laboratories is 0.40%.
（12）4Muffle furnace: a flame-muffle furnace, with resistance heating on the periphery of the furnace. A temperature controller should be used to accurately control the furnace temperature and calibrate it regularly.
Filter paper: three types of ash-free quantitative filter paper: fast, medium and slow. 5.6
Glass volumetric vessels: burette, volumetric flask, pipette, weighing bottle. 5.7Magnetic stirrer: a stirrer with a plastic shell, equipped with a speed control device. 6
GB/T5484~2000
5:8Spectrophotometer: can measure the absorbance of the solution in the range of 400nm~700nm, with 10mm and 20mm cuvettes. 5.9Flame photometer: with 768nm and 589nm interference filters. 5.10Ion meter or acidity meter: with fluoride ion selective electrode and saturated potassium chloride calomel electrode. 6 Preparation of the sample
According to the method of GB/T2007.1, the sample sent to the laboratory should be a representative and uniform sample. Use the quartering method to reduce to about 100g, sieve through a 0.080mm square hole sieve, use a magnet to absorb the metal iron in the sieve residue, grind the sieve residue to make it pass through the 0.080mm square hole sieve. After the sample is fully mixed, put it into a bottle with a ground stopper and seal it. 7 Determination of attached water (standard method)
7.1 Analysis steps
Weigh about 1g of sample (ma), accurate to 0.0001g, put it into a weighing bottle with a ground stopper that has been dried to a constant weight, and dry it in an oven at 45℃±3C for 1h (the weighing bottle should be loosened during the drying process), take it out, cover it with a ground stopper (but not too tightly), and put it in a desiccator to cool to room temperature. Cover the ground stopper tightly and weigh it. Then, remove the cover of the weighing bottle and place it in the oven, and dry it at the same temperature for 30 minutes. Repeat the drying, cooling, and weighing until the weight is constant. 7.2 Result expression
The mass percentage of attached water X is calculated according to formula (9): ms - mt × 100
Where: X, - mass percentage of attached water, %; mass of the sample before drying, g;
m4 - mass of the sample after drying, g.
7.3 Allowable difference
The allowable difference in the same laboratory is 0.20%.
8 Determination of crystal water (standard method)
8.1 Analytical steps
(9)
Weigh about 1g of sample (ms) to an accuracy of 0.0001g, put it into a weighing bottle with a ground-mouth stopper that has been dried and has a constant weight, heat it in an oven at 230℃±5℃ for 1h, take out the weighing bottle with tongs, cover it with a ground-mouth stopper, put it in a desiccator to cool to room temperature, and weigh it. Then put it in an oven and heat it at the same temperature for 30min, repeat heating, cooling, and weighing until a constant weight is achieved. 8.2 Result expression
The mass percentage of crystal water X2 is calculated according to formula (10): Xz= ms= me × 100 - X
Wherein: X, —-mass percentage of crystal water, %; ms—mass of sample before heating, g;
mg—mass of sample after heating, g;
X, —-mass percentage of attached water measured according to 7.2, %. 8.3 Allowable difference
The allowable difference for the same laboratory is 0.15%;
The allowable difference for different laboratories is 0.20%.
(10)
9 Determination of acid-insoluble matter (standard method)
9.1 Analytical steps
GB/T5484—2000
Weigh about 0.5g of sample (mt), accurate to 0.0001g, place in a 250mL beaker, moisten with water and cover with blood. Slowly add 40mL of hydrochloric acid (1+5) from the mouth of the beaker. After the reaction stops, rinse the surface III and the wall of the beaker with water and dilute to about 75mL. Heat and boil for 3min~4min, filter with slow filter paper, wash with hot water until there is no chloride ion (see 3.6). Transfer the residue and filter paper to a calcined and constant-weight porcelain crucible. Ash, calcine at 950℃~1000℃ for 20min, take out, put in a desiccator, cool to room temperature, and weigh. Repeat calcination, cooling, and weighing until constant weight is achieved. 9.2 Result Expression
The mass percentage X of acid insoluble matter is calculated according to formula (11): Xg = m ×100
Wherein: X3—mass percentage of acid insoluble matter, %; mg—mass of residue after ignition, g,
—mass of sample, g.
9.3 Allowable Difference
The allowable difference in the same laboratory is 0.15%;
The allowable difference in different laboratories is 0.20%.
10 Determination of Sulfur Trioxide (Standard Method)
10.1 Summary of Method
(11)
In an acidic solution, sulfate is precipitated with barium chloride solution, filtered and ignited, and weighed in the form of barium sulfate. The determination result is calculated as sulfur trioxide.
10.2 Analysis steps
Weigh about 0.2g of sample (mg), accurate to 0.0001g, place in a 300mL beaker, add 30mL40mL water to disperse it. Add 10mL hydrochloric acid (1+1), crush the lumps with a flat glass rod, and slowly heat the solution until the sample is completely decomposed. Heat the solution to a slight boil for 5min. Filter with medium-speed filter paper and wash with hot water 10~12 times. Adjust the volume of the filtrate to 200mL, boil, add 15mL of barium chloride solution (see 4.9) dropwise while stirring, continue boiling for several minutes, then move to a warm place and let stand for 4h or overnight (the volume of the solution should be kept at 200mL at this time). Filter with slow filter paper and wash with warm water until it is tested to be free of nitrogen ions (see 3.6). Transfer the precipitate and filter paper to the porcelain that has been burned to a constant weight. After ashing, burn in a muffle furnace at 800℃ (see 5.4) for 30 minutes. Take out the crucible and place it in a desiccator to cool to room temperature and weigh it. Repeat the burning until the weight is constant. 10.3 Result expression
The mass percentage of sulfur trioxide Xso is calculated according to formula (12): Xxs, X0. 343 × 100
Where: Xso,
The mass percentage of sulfur trioxide, %;
The mass of the precipitate after burning, g;
The mass of the sample, g;
0.343——The conversion coefficient of sulfur trioxide to sulfur trioxide. 10.4 Allowable difference
The allowable difference of the same laboratory is 0.25%:
The allowable difference of different laboratories is 0.40%.
（12）4Muffle furnace: a flame-muffle furnace, with resistance heating on the periphery of the furnace. A temperature controller should be used to accurately control the furnace temperature and calibrate it regularly.
Filter paper: three types of ash-free quantitative filter paper: fast, medium and slow. 5.6
Glass volumetric vessels: burette, volumetric flask, pipette, weighing bottle. 5.7Magnetic stirrer: a stirrer with a plastic shell, equipped with a speed control device. 6
GB/T5484~2000
5:8Spectrophotometer: can measure the absorbance of the solution in the range of 400nm~700nm, with 10mm and 20mm cuvettes. 5.9Flame photometer: with 768nm and 589nm interference filters. 5.10Ion meter or acidity meter: with fluoride ion selective electrode and saturated potassium chloride calomel electrode. 6 Preparation of the sample
According to the method of GB/T2007.1, the sample sent to the laboratory should be a representative and uniform sample. Use the quartering method to reduce to about 100g, sieve through a 0.080mm square hole sieve, use a magnet to absorb the metal iron in the sieve residue, grind the sieve residue to make it pass through the 0.080mm square hole sieve. After the sample is fully mixed, put it into a bottle with a ground stopper and seal it. 7 Determination of attached water (standard method)
7.1 Analysis steps
Weigh about 1g of sample (ma), accurate to 0.0001g, put it into a weighing bottle with a ground stopper that has been dried to a constant weight, and dry it in an oven at 45℃±3C for 1h (the weighing bottle should be loosened during the drying process), take it out, cover it with a ground stopper (but not too tightly), and put it in a desiccator to cool to room temperature. Cover the ground stopper tightly and weigh it. Then, remove the cover of the weighing bottle and place it in the oven, and dry it at the same temperature for 30 minutes. Repeat the drying, cooling, and weighing until the weight is constant. 7.2 Result expression
The mass percentage of attached water X is calculated according to formula (9): ms - mt × 100
Where: X, - mass percentage of attached water, %; mass of the sample before drying, g;
m4 - mass of the sample after drying, g.
7.3 Allowable difference
The allowable difference in the same laboratory is 0.20%.
8 Determination of crystal water (standard method)
8.1 Analytical steps
(9)
Weigh about 1g of sample (ms) to an accuracy of 0.0001g, put it into a weighing bottle with a ground-mouth stopper that has been dried and has a constant weight, heat it in an oven at 230℃±5℃ for 1h, take out the weighing bottle with tongs, cover it with a ground-mouth stopper, put it in a desiccator to cool to room temperature, and weigh it. Then put it in an oven and heat it at the same temperature for 30min, repeat heating, cooling, and weighing until a constant weight is achieved. 8.2 Result expression
The mass percentage of crystal water X2 is calculated according to formula (10): Xz= ms= me × 100 - X
Wherein: X, —-mass percentage of crystal water, %; ms—mass of sample before heating, g;
mg—mass of sample after heating, g;
X, —-mass percentage of attached water measured according to 7.2, %. 8.3 Allowable difference
The allowable difference for the same laboratory is 0.15%;
The allowable difference for different laboratories is 0.20%.
(10)
9 Determination of acid-insoluble matter (standard method)
9.1 Analytical steps
GB/T5484—2000
Weigh about 0.5g of sample (mt), accurate to 0.0001g, place in a 250mL beaker, moisten with water and cover with blood. Slowly add 40mL of hydrochloric acid (1+5) from the mouth of the beaker. After the reaction stops, rinse the surface III and the wall of the beaker with water and dilute to about 75mL. Heat and boil for 3min~4min, filter with slow filter paper, wash with hot water until there is no chloride ion (see 3.6). Transfer the residue and filter paper to a calcined and constant-weight porcelain crucible. Ash, calcine at 950℃~1000℃ for 20min, take out, put in a desiccator, cool to room temperature, and weigh. Repeat calcination, cooling, and weighing until constant weight is achieved. 9.2 Result Expression
The mass percentage X of acid insoluble matter is calculated according to formula (11): Xg = m ×100
Wherein: X3—mass percentage of acid insoluble matter, %; mg—mass of residue after ignition, g,
—mass of sample, g.
9.3 Allowable Difference
The allowable difference in the same laboratory is 0.15%;
The allowable difference in different laboratories is 0.20%.
10 Determination of Sulfur Trioxide (Standard Method)
10.1 Summary of Method
(11)
In an acidic solution, sulfate is precipitated with barium chloride solution, filtered and ignited, and weighed in the form of barium sulfate. The determination result is calculated as sulfur trioxide.
10.2 Analysis steps
Weigh about 0.2g of sample (mg), accurate to 0.0001g, place in a 300mL beaker, add 30mL40mL water to disperse it. Add 10mL hydrochloric acid (1+1), crush the lumps with a flat glass rod, and slowly heat the solution until the sample is completely decomposed. Heat the solution to a slight boil for 5min. Filter with medium-speed filter paper and wash with hot water 10~12 times. Adjust the volume of the filtrate to 200mL, boil, add 15mL of barium chloride solution (see 4.9) dropwise while stirring, continue boiling for several minutes, then move to a warm place and let stand for 4h or overnight (the volume of the solution should be kept at 200mL at this time). Filter with slow filter paper and wash with warm water until it is tested to be free of nitrogen ions (see 3.6). Transfer the precipitate and filter paper to the porcelain that has been burned to a constant weight. After ashing, burn in a muffle furnace at 800℃ (see 5.4) for 30 minutes. Take out the crucible and place it in a desiccator to cool to room temperature and weigh it. Repeat the burning until the weight is constant. 10.3 Result expression
The mass percentage of sulfur trioxide Xso is calculated according to formula (12): Xxs, X0. 343 × 100
Where: Xso,
The mass percentage of sulfur trioxide, %;
The mass of the precipitate after burning, g;
The mass of the sample, g;
0.343——The conversion coefficient of sulfur trioxide to sulfur trioxide. 10.4 Allowable difference
The allowable difference of the same laboratory is 0.25%:
The allowable difference of different laboratories is 0.40%.
（12）0001g, put it into a weighing bottle with a ground stopper that has been dried and constant, heat it in an oven at 230℃±5℃ for 1h, take out the weighing bottle with tongs, cover it with a ground stopper, put it in a desiccator to cool to room temperature, and weigh it. Then put it in an oven and heat it at the same temperature for 30min. Repeat heating, cooling, and weighing until constant weight is reached. 8.2 Result expression
The mass percentage of crystal water X2 is calculated according to formula (10): Xz= ms= me × 100 - X
Where: X, —-mass percentage of crystal water, %; ms—mass of sample before heating, g;
mg mass of sample after heating, g;
X, according to 7.2, the mass percentage of attached water is measured, %. 8.3 Allowable difference
The allowable difference in the same laboratory is 0.15%;
The allowable difference in different laboratories is 0.20%.
(10)
9 Determination of acid-insoluble matter (standard method)
9.1 Analytical steps
GB/T5484—2000
Weigh about 0.5g of sample (mt), accurate to 0.0001g, place in a 250mL beaker, moisten with water and cover with blood. Slowly add 40mL of hydrochloric acid (1+5) from the mouth of the beaker. After the reaction stops, rinse the surface III and the wall of the beaker with water and dilute to about 75mL. Heat and boil for 3min~4min, filter with slow filter paper, wash with hot water until there is no chloride ion (see 3.6). Transfer the residue and filter paper to a calcined and constant-weight porcelain crucible. Ash, calcine at 950℃~1000℃ for 20min, take out, put in a desiccator, cool to room temperature, and weigh. Repeat calcination, cooling, and weighing until constant weight is achieved. 9.2 Result Expression
The mass percentage X of acid insoluble matter is calculated according to formula (11): Xg = m ×100
Wherein: X3—mass percentage of acid insoluble matter, %; mg—mass of residue after ignition, g,
—mass of sample, g.
9.3 Allowable Difference
The allowable difference in the same laboratory is 0.15%;
The allowable difference in different laboratories is 0.20%.
10 Determination of Sulfur Trioxide (Standard Method)
10.1 Summary of Method
(11)
In an acidic solution, sulfate is precipitated with barium chloride solution, filtered and ignited, and weighed in the form of barium sulfate. The determination result is calculated as sulfur trioxide.
10.2 Analysis steps
Weigh about 0.2g of sample (mg), accurate to 0.0001g, place in a 300mL beaker, add 30mL40mL water to disperse it. Add 10mL hydrochloric acid (1+1), crush the lumps with a flat glass rod, and slowly heat the solution until the sample is completely decomposed. Heat the solution to a slight boil for 5min. Filter with medium-speed filter paper and wash with hot water 10~12 times. Adjust the volume of the filtrate to 200mL, boil, add 15mL of barium chloride solution (see 4.9) dropwise while stirring, continue boiling for several minutes, then move to a warm place and let stand for 4h or overnight (the volume of the solution should be kept at 200mL at this time). Filter with slow filter
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