JB/T 9225-1999 Chemical analysis methods for foundry clay and bentonite
Some standard content:
JB/T 9225-. 1999
This standard is a revision of Z13J3100789 "Chemical analysis method of clay and bentonite for casting". During the revision, editorial changes were made to the original standard, and the main technical content remained unchanged. This standard replaces ZBJ3100789 from the date of implementation. This standard was proposed and managed by the National Technical Committee for Foundry Standardization. The responsible drafting unit of this standard is Shenyang Foundry Research Institute. The main drafters of this standard are Zhou Yusun, Zhao Shulin, Zhang Qiao, Ding Quangen, Tao Rulin, Zhang Aimin, Yi Qunchi, Cai Limin, Wang Wenqi, and Zhang Wenge.
1 Scope
Mechanical Industry Standard of the People's Republic of China
Method for chemical analysis of clay and bentonite for casting fonudry
This standard specifies the chemical analysis method of foundry clay and bentonite JB/T9225
Replaces ZBJ31007---89
This standard is applicable to the determination of the following chemical components and cation exchange capacity and exchangeable cation content in foundry clay and bentonite. The determination range is as follows:
Loss on ignition 0.5%~15%;
Silicon dioxide 50%~～75%;
Aluminum oxide 10%～30%;
Iron oxide 0.1%~7%;
Titanium oxide 0.05%~2%;
Calcium oxide
0.1%~7%;
Magnesium oxide
0. 01%~0. 1%;
Manganese oxide
Potassium oxide 0.1%～4%;
Sodium oxide
Cation exchange capacity
10~100mmol(NH,+)/100g ±,
Exchangeable calcium ion
Exchangeable magnesium ion
Exchangeable sodium ion
Exchangeable potassium ion
2 General
-Ca2+)/100g ±;
1~～~60m mol(→
Mg*+)/100g +;
0.1~10m mol(-
1~60m mol(Na+)/100g ±;bzxZ.net
0. 5~10m mol(K+)/100g ±.
2.1 The determination methods listed in parallel in this standard can be selected according to specific circumstances. 2.2 The water used in reagent preparation and operation shall be distilled water or deionized water, and the chemical reagents used shall be analytically pure or high-grade pure reagents: the chemical reagents used to prepare or calibrate standard solutions shall be reference or high-purity reagents. 2.3 The acid or nitrogen water used in the test, if the concentration is not indicated, is the original concentration. 2.4 Except for those with specified solvents, all prepared solutions are aqueous solutions. The percentage concentration of a solution refers to the number of grams of solute contained in 100 ml of solution. "1 + 1\" "1 + 2" etc. refer to the volume ratio of any liquid reagent to water. 2.5 The analytical balance used should be accurate to 0.0001 g, balance and weight should be calibrated regularly, instruments and volumetric apparatus should be calibrated 2.6 Gravimetric weighing to "constant weight" means that the burning and cooling procedures are repeated until the difference between the last two weighings is no more than 0.0002g. Approved by the State Bureau of Machinery Industry on June 24, 1999 562
Implementation on January 1, 2000
3 Method Summary
3.1 Determination of loss on ignition
JB/T9225.-1999
The water of ignition, carbonate, sulfide, organic matter and other volatile substances contained in the sample are decomposed and volatilized after burning at 1000~1050C, and the weight loss is the loss on ignition. 3.2 Determination of silicon dioxide
Dehydration weight under hydrochloric acid distillation (molybdenum blue absorption photometry) The sample is melted and decomposed with sodium carbonate, the fused mass is dissolved with hydrochloric acid, and the silicic acid is evaporated to dryness to dehydrate, hydrochloric acid is added to dissolve the soluble salts, filtered and burned to silicon dioxide, and then treated with hydrofluoric acid to make silicon escape in the form of silicon tetrafluoride. The weight difference before and after the hydrofluoric acid treatment is the amount of silicon dioxide in the precipitate. The amount of residual silicon dioxide in the filtrate is determined by the button blue absorption photometry, and the sum of the two is the content of silicon dioxide in the sample. Agglomeration weight (molybdenum blue absorption photometry) The sample is melted with sodium carbonate and boric acid, leached with hydrochloric acid, polyethylene oxide is added to agglomerate the silicic acid, filtered and burned to silicon dioxide, and then treated with hydrofluoric acid to make silicon escape in the form of silicon tetrafluoride. The weight difference before and after the hydrofluoric acid treatment is the amount of silicon dioxide in the precipitate. The amount of silicon dioxide remaining in the filtrate is determined by molybdenum blue absorptiometry. The sum of the two is the silicon dioxide content in the sample.
3.3 Determination of aluminum oxide
EDTA complexometric titration method Take the filtrate after silicon measurement, add excess EDTA solution, and complex aluminum, iron, titanium, etc. with EDTA in a weakly acidic solution, using PAN as an indicator. Back-titrate the excess EDTA with copper standard solution, then replace the EDTA complexed with aluminum and titanium with sodium fluoride, and finally titrate the replaced EIDTA with copper standard solution until purple-red is the end point. According to the consumption of the second copper standard solution, calculate the content of aluminum oxide and titanium oxide, and obtain the content of aluminum oxide by the difference between the total amount of aluminum and titanium oxides and the amount of titanium oxide. 3.4 Determination of Iron Oxide
O-phenanthroline Absorption Spectrophotometry Separate the filtrate after silicon measurement, use hydroxylamine hydrochloride to reduce iron (III) to iron (I), in the ammonium acetate medium with pH 5.5, o-phenanthroline and iron (III) form an orange-red complex, measure the absorbance at a wavelength of 510nm, and calculate the oxidation content according to the working curve.
3.5 Determination of Titanium Oxide
Diantipyryl methane Absorption Spectrophotometry Separate the filtrate after silicon measurement, in a 1.5-2.0 mol/L hydrochloric acid medium, use ascorbic acid to reduce and eliminate the interference of iron (III), add diantipyryl methane to form a yellow soluble complex with titanium, measure the absorbance at a wavelength of 390nm, and calculate the titanium oxide content according to the working curve. Hydrogen peroxide absorption spectrophotometry: Take the filtrate after silicon measurement, complex iron with phosphate, add hydrogen peroxide, make it form yellow soluble complex with titanium, measure absorbance at wavelength 410nm, and calculate titanium oxide content according to working curve. 3.6 Determination of calcium, magnesium, manganese, potassium and sodium oxides: Decompose the sample with hydrofluoric acid, nitric acid and perchloric acid to remove silicon, evaporate with perchloric acid to remove fluoride, extract the residue with dilute hydrochloric acid and dilute to a certain volume, separate the solution to determine calcium, magnesium, manganese, potassium and sodium oxides. 3.6.1 Determination of calcium oxide: EDTA complexometric titration: triethanolamine is used to mask interfering elements such as iron and aluminum, and calcium is titrated with EDTA standard solution in a strong alkaline medium with calcein-eugenol-acridine as mixed indicator. 3.6.2 Determination of magnesium oxide
EDTA complexometric titration method: triethanolamine is used to mask interfering elements such as iron and aluminum. In an ammonia buffer medium, acid blue K-naphthol green B is used as a mixed indicator, and the EDTA standard solution is used to titrate the total amount of calcium and magnesium. The magnesium oxide content is calculated by the difference between the titrated calcium and magnesium total amount and the volume of the EDTA standard solution consumed for the titration of calcium. 3.6.3 Determination of manganese oxide
Ammonium persulfate oxidation (permanganate absorptiometry) In a perchloric acid medium, silver nitrate is added, and ammonium persulfate is used to oxidize manganese (I) to purple-red permanganate ions. The absorbance is measured at a wavelength of 530nm, and the manganese oxide content is calculated based on the working curve. 3.6.4 Determination of potassium and sodium oxides
JB/T9225
Flame photometry method: On a flame photometer, the emission intensity values of copper and sodium in the test solution are measured, and the content of potassium and sodium oxides is calculated based on the T curve.
3.7 Determination of oxides of iron, calcium, magnesium, manganese, potassium and sodium by atomic absorption spectrophotometry After the sample is decomposed and desiliconized by hydrofluoric acid and perchloric acid, the residue is dissolved with dilute hydrochloric acid, and the release agent strontium is added to eliminate the interference of aluminum on calcium and magnesium. The absorbance is measured by air-acetylene flame on the atomic absorption spectrophotometer, and the content of oxides of each element is calculated based on the curve.
3.8 Determination of cation exchange capacity and exchangeable cations of calcium, magnesium, sodium and potassium in bentonite After the sample is washed with dilute ethanol solution, ammonium chloride ethanol solution is added and fully stirred on a magnetic stirrer to completely exchange ammonium ions with exchangeable calcium, magnesium, sodium, potassium and other ions in the sample, and then centrifuged and separated, and the amount of ammonium ions exchanged in the sediment is determined by distillation method. The cation exchange capacity in the sample is calculated based on this. The calcium, magnesium, sodium and potassium ions entering the solution are determined by atomic absorption spectrophotometry or complexometric titration and flame photometry.
4 Preparation and weighing of samples
4.1 The samples must be representative and homogeneous, without any foreign impurities. 4.2 The samples are divided into quarters, and about 20g of samples are obtained. Grind until all of them pass through a 75m sieve (i.e., a 200! sieve) 4.3 Place the above sample in a weighing bottle, dry at 105~110℃ for 3h, then put it in a desiccator, cool it down to room temperature and weigh it. 4.4 When weighing the sample, always use a weighing bottle to weigh it by difference subtraction. 5 Determination of loss on ignition
5.1 Analysis steps
Weigh 1g of sample, accurate to 0.0001g. Place it in a constant-weight platinum bowl, cover it (leave a small gap), put it in a high-temperature furnace, gradually heat it to 1000~1050℃, and keep it at this temperature for 1h. Take it out and cool it to room temperature in a desiccator, and weigh it. Repeat this operation (burn for 15min each time) until constant weight.
5.2 Calculation of analysis results
Calculate the percentage of loss on ignition in the sample according to formula (1): ml-m2×100%
Loss on ignition-
Wuzhong m--
Mass of the sample and crucible before ignition, g;
m2-Mass of the sample and crucible after ignition, g; Mass of the sample, g.
5.3 Allowable difference
The difference in analysis results between laboratories should not be greater than the allowable difference listed in Table 1. Table 1
Loss on ignition
>1. 00～~5. 00
>5. 00~~10. 00
6 Determination of silicon dioxide
6.1 Hydrochloric acid single distillation dehydration weight (molybdenum blue absorption photometric method) 6.1.1 Reagents
Tolerance
Anhydrous sodium carbonate.
Hydrochloric acid.
Hydrochloric acid (1+1,5+95.1+11).
Hydrofluoric acid.
Hydrofluoric acid (19), stored in a plastic bottle. Sulfuric acid (1)
Boric acid solution (4%), stored in a plastic bottle. Silver nitrate dissolved in carboxylic acid (1%), stored in a brown bottle. Ethanol (95%).
Nitrogen water.
JB/T9225 --- 1999
Para-nitrophenol indicator solution (0.5%), prepared with alcohol (95%). Ammonium molybdate solution (5%), stored in a plastic bottle. Tartaric acid solution (10%), stored in a plastic bottle. Reducing agent solution Dissolve 0.7g of anhydrous sodium sulfate in 10mL of water, add 0.5g of 1-amino-2-naphthol-4-sulfonic acid, stir to dissolve. Dissolve 9.0g of sodium bisulfite in water, combine with the former solution, dilute to 100mL with water, store in a plastic bottle, keep in a dark place, and use for no more than two weeks. Silica standard solution (0.04mgSiO2/mL) Weigh 0.1000g of oxidized sodium hydroxide that has been calcined at 1150°C for 1h into a crucible, add 2g of anhydrous sodium carbonate, mix well, then cover with 1g, cover, and place in a high-temperature furnace. Heat at low temperature first, and gradually increase the temperature to 1000-1050°C to obtain a transparent melt. Cool, place in a plastic cup, soak with boiling water and rinse with a small amount of water, cool to room temperature, transfer to a 250ml volumetric flask, dilute with water to the mark, shake, and transfer to a dry plastic bottle for storage. Pipette 10.0ml of the above solution into a 100ml volumetric flask, dilute with water to the mark, shake, and transfer to a plastic bottle for storage. 6.1.2 Instrument||t t||Spectrophotometer.
6.1.3 Analysis steps
Weigh 0.5g of sample, accurate to 0.0001g, place in platinum (the volume of the platinum crucible is about 30-50mL), add 2g of anhydrous sodium carbonate, mix with the sample, then take 1g of anhydrous sodium carbonate to cover the surface, cover, and place in a high-temperature furnace. Start from a low temperature and gradually increase the temperature to 1000-1050, and maintain this temperature for 15-20 minutes. Clamp the crucible with crucible tongs wrapped with platinum heads, rotate carefully so that the molten material is evenly attached to the inner wall, and cool. Place the crucible and lid in a porcelain evaporating dish, add 40ml of hydrochloric acid (1+1), cover with Table III, and Heat on a water bath until the frit is completely dissolved. Rinse and cover with a small amount of water. Place the porcelain evaporator on a water bath again to heat and evaporate to dryness, and use a flat glass rod to continuously crush the precipitated salts into powder. Then place the porcelain evaporator in an oven and bake at 130C for 1 hour. Take out the porcelain III, cool it slightly, add 5ml of hydrochloric acid, leave it for 5 minutes, add 20ml of hot water, stir to dissolve the salts, add an appropriate amount of filter paper pulp and stir evenly, filter with medium-speed quantitative filter paper, collect the filtrate and washing liquid in a 250mL volumetric flask, wash the precipitate and precipitate with hot hydrochloric acid (5+95) 3~5 times, and continue to wash with hot water until there is no fluoride [check with silver nitrate solution (1%)". Transfer the precipitate and filter paper to a platinum crucible, add 2 drops of sulfuric acid (1 + 1) to the precipitate, dry it on a hot plate at low temperature, then transfer it to a high-temperature furnace, gradually increase the temperature to fully incinerate the filter paper, and finally burn it at 1150°C ± 25°C for 1h, take out the sealed crucible, place it in a desiccator to cool to room temperature, and weigh it. Repeat the burning until constant weight. Moisten the precipitate with water, add 3 drops of sulfuric acid (1 + 1) and 10mL of hydrofluoric acid, and evaporate it on a low-temperature hot plate until white smoke comes out. Remove it, cool it slightly, add 5ml of hydrofluoric acid, and continue heating until all sulfur trioxide white smoke is emitted. Place it in a high-temperature furnace, burn it at 1150°C ± 25°C for 15min, take it out, cool it to room temperature in a desiccator, and weigh it. Repeat the burning until constant weight. The weight difference before and after hydrofluoric acid treatment is the weight of silicon oxide. Add about 2g of potassium pyrosulfate to the residue, cover and place in a high-temperature furnace, gradually increase the temperature at 700~750 (melt to transparent state, take out, cool, leached with hot water, rinse the crucible and cover with a small amount of water. Cool to room temperature, add to the silicon dioxide filtrate, dilute with water to the standard line. Shake well. This solution is the sample solution (1), which is used to determine the residual silicon dioxide and aluminum oxide, iron oxide and titanium oxide content: 565
JB /T9225—1999
Put 10.0 ml of test solution (A) into a 100 ml plastic cup, add 2 ml of hydrofluoric acid (1+9), shake well, let stand for 10 min, add 10 ml of boric acid solution (4%), add 1 drop of p-nitrophenol indicator, add ammonia water until the solution just turns yellow, add 10 ml of hydrochloric acid (1+11), 5 ml of ethanol (95%), 6 ml of ammonium acid solution (5%), shake well, let stand in a warm water bath at 30-50°C for 5-10 min, cool Cool to room temperature, add 5ml tartaric acid solution (10%), shake well, add 2ml reducing agent solution, transfer to 100ml volumetric flask, dilute with water to the mark, add and place for 30min, use reagent blank as reference, select 1cm colorimetric dish, measure the absorbance of solution at wavelength 650nm on spectrophotometer, and find out the amount of silicon dioxide from the working curve.
6.1.4 Drawing of working curve
Pipette 0, 1.00, 2.00, 3.00, 4.00, 5.00mL silica standard solution (0.04mgSiO2/ml) are placed in 6 100mL plastic cups (SiO0~0.2mg), and 2ml hydrofluoric acid (1+9) is added to each. The following operations are carried out according to the analysis steps, the absorbance is measured, and the working curve is drawn.
6.1.5 Calculation of analysis results
Calculate the percentage of silica in the sample according to formula (2): Si0, (mm) + Cx250/10×100% ...
Where: ml is the mass of the precipitate and the platinum crucible before hydrofluoric acid treatment, m2 is the mass of the residue and platinum after hydrofluoric acid treatment, gC-
The amount of silicon dioxide in the filtrate obtained from the working curve, g; m
is the mass of the sample, g.
6.1.6 Allowable difference
The difference in analytical results between laboratories should not exceed 0.50%. 6.2 Condensation weight (molybdenum blue absorption photometry) 6.2.1 Reagents
Boric acid.
Polyethylene oxide solution (0.05%): Weigh 0.1g polyethylene oxide and add it in small amounts to a 300mL beaker containing 150ml of water while stirring continuously , after it is dissolved, dilute it to 200ml with water and mix. Filter it with medium-speed filter paper and store it in a plastic bottle. The usage time should not exceed two weeks.
The other reagents are the same as 6.1.1.
6.2.2 Instrument
Spectrophotometer.
6.2.3 Analysis steps
Weigh 0.5g of sample, accurate to 0.0001g, put it in a platinum crucible (the volume of the platinum crucible is about 30~50mL), add 2g of anhydrous sodium carbonate and 0.2g of boric acid, mix it with the sample, then take 1g of anhydrous sodium carbonate to cover the surface, cover it, put it in a high-temperature furnace, start from low temperature and gradually raise the temperature to 1000~1050℃, and keep it at this temperature for 15~20min. Clamp it with a crucible clamp with a platinum head, rotate it carefully, so that the molten material is evenly attached to the inner wall of the crucible, and cool it. Place the crucible and lid in a porcelain evaporating dish, add 40mL of hydrochloric acid (1+1), cover with a watch glass, heat on a water bath until the frit is completely dissolved, rinse the crucible and lid with a small amount of water. Place the evaporating dish on a water bath again, and evaporate until the volume of the solution is 15mL.After the mixture is cooled, remove it and cool it. Add an appropriate amount of filter paper pulp, stir evenly, add 10mL polyethylene oxide solution (0.05%), stir evenly, and let it stand for 5 minutes. Filter with medium-speed quantitative filter paper, and collect the filtrate and washing liquid in a 250mL volumetric flask. Wash the III wall and precipitate with hot hydrochloric acid (5+95) 3~~5 times, and continue to wash with hot water until the chloride ion is dead [check with silver nitrate solution (1%). Transfer the precipitate and filter paper into a platinum crucible together, and add 2 drops of sulfuric acid (1+1) on the precipitate. The following steps are carried out according to 6.1.3. 6.2.4 Drawing of working curve
Same as 6.1.4.
6.2.5 Calculation of analysis results
Calculate the percentage of silicon dioxide in the sample according to formula (3): 566
JB/T92251999
Si0z(ml-m)+cx250/10)
Wherein: ml·mass of precipitate and platinum crucible before hydrofluoric acid treatment·g; m2—mass of residue and platinum crucible after hydrofluoric acid treatment, g; C-amount of silicon dioxide in the filtrate obtained from the working curve, g; m mass of sample, g.
6.2.6 Tolerable error
The difference in analysis results between laboratories should not be less than 0.50%. 7 Determination of aluminum oxide (EDTA complexometric titration) 7.1 Reagents
Hydrochloric acid (1+1,1+9).
Ammonia water (1+1).
P-nitrophenol indicator solution (0.1%). 1-(2-pyridylazo)-2-naphthol (PAN) indicator solution (0.1%), prepared with ethanol. (3)
Acetic acid-ammonium acetate buffer solution (pH 4.5), take 80g of ammonium acetate and dissolve it in water, add 60mL of glacial acetic acid and dilute with water to 1000mL and mix.
Sodium fluoride.
Ethylenediammonium tetraacetate disodium (EDTA) solution (0.02mol/L) Weigh 7.44g of EDTA, dissolve it in 500ml. warm water, cool it down and dilute it with water to 1000mL, mix it evenly.
Copper standard solution (0.010mol/L) Weigh 0.6354g of pure copper in a 250mL beaker, add 30mL of nitric acid (1--3), heat to dissolve, boil it to drive out nitrogen oxides, and cool it down. Neutralize with ammonia water until hydroxide appears, add hydrochloric acid until just dissolved, transfer to a 1000ml volumetric flask, dilute to the mark with water, and shake well. 7.2 Analysis steps
Pull 25.0ml of test solution (A) into a 250ml conical flask, add 50mL of water, add 10-20ml of ETA solution (0.02mol/L, this solution contains approximately 2% alumina per milliliter in the sample), the amount should be enough to completely complex the aluminum ions in the solution, and the excess should be about 5ml. Add 2 drops of p-nitrophenol indicator solution (0.1%) and heat to near boiling. Neutralize with ammonia water (1+1) until the solution just turns yellow, then add hydrochloric acid (1+1) until the solution just fades. Add 10mL of acetic acid-ammonium acetate buffer solution (pH 4.5), heat and boil for 5 minutes, remove the test solution when the temperature is 80-90°C, add 6 drops of PAN indicator solution (0.1%), and titrate with steel standard solution (0.01mnl/1.) until purple-red is the first end point (do not record the reading). Add 1.5 boxes of sodium fluoride, heat and boil for 5 minutes, remove the test solution when the temperature is 80-90°C, and then titrate with copper standard solution (0.010mol/L) until the test solution changes from yellow to stable purple-red or purple-blue as the end point. Record the milliliters of copper standard solution consumed in the second titration. The consumed copper standard solution is equivalent to the total amount of aluminum and titanium in the test solution. 7.3 Calculation of analysis results
Calculate the percentage of aluminum oxide in the sample according to formula (4): VX(250/25)×5.098X10- × 100% -Ti0,(%)×0.638 -Al,03
V is the volume of copper standard solution consumed during the second titration, ml. Where:
5.098×10--.-1mL copper standard solution (0.010mol/1.) is equivalent to the amount of aluminum oxide, gm—mass of sample, g,
TiO (%) is the percentage of titanium oxide in the sample measured according to 9.1 or 9.2, %. 7.4 Allowable difference
The difference in analysis results between laboratories should not be less than the allowable difference listed in Table 2. (4)
Aluminium oxide content
>15～20
8 Determination of iron oxide (o-phenanthroline absorptiometry) 8.1 Reagents
Ammonium acetate solution (20%).
Hydroxyamine hydrochloride solution (10%).
JB/T 9225---1999
Tolerance
O-phenanthroline solution (0.1%), weigh 0.5g o-phenanthroline, dissolve in 25mL ethanol, dilute to 500ml with water. Shake well and store in a dark place. If the solution changes colour during storage, prepare it again. Iron oxide standard solution (0.01mgFe0/ml) Weigh 0.1000g of ferric oxide that has been calcined at 400C for 30min, or 0.0699g of pure iron in a 100ml beaker, add 10mL of hydrochloric acid (1+1), heat to dissolve, cool and transfer to a 1000ml volumetric flask. Dilute to the mark with water and shake well. Pipette 50.0ml of the above solution into a 500ml volumetric flask, add 10ml of hydrochloric acid (1+1), dilute to the mark with water and shake well.
8.2 Instrument
Spectrophotometer.
8.3 Analysis steps
According to the iron oxide content in the sample, pipette the test solution (A) according to the amount specified in Table 3 into a 100ml volumetric flask, add 2ml. Hydroxylamine hydrochloride solution (10%), shake and add 10ml ammonium acetate solution (20%), 10ml o-phenanthroline solution (0.1%), dilute with water to the full mark, shake well and let stand for 30min, use the reagent blank as a reference, select 1cm colorimetric, and measure the absorbance of the solution at a wavelength of 510nm on a quasi-spectrophotometer. From the working curve, find the amount of iron oxide, Table 3
Iron oxide content
>0.50～1.50
>1. 50~~3. 00
8.4 Drawing of working curve
Taking the volume of test solution (A)
Putting 0, 1.00, 5.00, 10.00, 15.00, 20.00.25.00.30.00ml of standard iron oxide solution (0.01mgFe2O/ml) into 8 100mL volumetric flasks respectively (Fe2O.0~～0.3mg), the following operations are carried out according to the analysis steps, measuring the absorbance, and drawing the T. line.
8.5 Calculation of analysis results
Calculate the percentage of iron oxide in the sample according to formula (5): Fe:O.
-The amount of iron oxide is obtained from the working curve: Where: C—
.Taking the volume of test solution (A).mI.
m--.Sample mass, g.
Cx250/V
×100%
8.6 Allowable error
JB/T9225--- 1999
The difference between the analysis results of the experimental space should not be greater than the allowable error listed in Table 4. Table 4
Iron oxide content
20.50～1. 00
>1. 00~1. 50
>1. 50~～3. 00
Determination of titanium oxide
Diantipyryl methane absorption photometry
This method is applicable to the determination of titanium oxide content below 1.00% in the sample. 9.1.1 Reagents
Ascorbic acid solution (5%), prepared before use. Hydrochloric acid (1+1, 1+9).
Allow shame
Antipyrine methane solution (2%) Weigh 2g of diantipyrine methane, dissolve it with 30ml of hydrochloric acid (1+5), and dilute it with water to 100ml.
Standard titanium oxide solution (0.1mgTiO2/ml) Weigh 0.1000g of titanium oxide that has been pre-calcined at 950C for 2h in a platinum crucible, add about 3g of potassium pyrosulfate, melt it on a hot plate first, then move it to a lamp and melt it until it is transparent. After cooling, use hydrochloric acid (1+9) to heat and dissolve the molten block at below 50C. After cooling, transfer it to a 1000ml. volumetric flask, dilute it with hydrochloric acid (1+9) to the mark, and shake it. Standard titanium oxide solution (0.01mgTiO2/mL) Pipette 50.0ml of the above standard titanium oxide solution (0.1mgTiO2/ml). 1500ml, in a volumetric flask, dilute to the mark with hydrochloric acid (1 + 9), shake well. 9.1.2 Instrument
Spectrophotometer.
9.1.3 Analysis steps
According to the titanium oxide content in the sample, pipette the test solution (A) as specified in Table 5 into a 50mL volumetric flask, add 8ml hydrochloric acid (1~1), 2ml ascorbic acid solution (5%), shake well to completely reduce the iron, then add 10ml diantipyrine methane solution (2%), dilute with water to the mark, shake and hang, after leaving for 1h, use water as a reference, select 1cm colorimetric III, measure the absorbance at a wavelength of 390nm on a spectrophotometer, and find the titanium oxide content from the working curve.
>0.20～0.50
≥0. 50 ~1. 00
9.1.4 Drawing of working curve
Divide the volume of test solution (A)
Pipette titanium oxide standard solution (0.01mgTi0z/mL) 0, 1.00, 2.00.4.00, 6.00, 8.00, 10.00ml.1i0.00.1mg), place them in 7 50l volumetric flasks respectively, add 8ml. hydrochloric acid (1+1), and perform the following operations according to the analysis steps to measure the absorbance: Draw I curve
9.1.5 Calculation of analysis results
JB/T 9225---1999
Calculate the percentage of titanium oxide in the sample according to formula (6): TiO,-
Wherein: C—amount of titanium oxide obtained from the working curve·g; V
volume of the test solution (A), mL;
mass of the sample, g.
9.1.6 Allowable difference
CX250/V
×100%
The difference in the analysis results between laboratories should not be greater than the allowable difference listed in Table 6. Table 6
Iron oxide content
>0. 10~~0.50
>0. 50~～1. 00
9.2 Peroxide oxygen absorption photometry
This method is applicable to the determination of titanium oxide content above 0.50% in the sample. 9.2.1 Reagents
Phosphoric acid (→1).
Hydrogen peroxide (1+9).
Hydrochloric acid (1+9).
Titanium oxide standard solution (0.1mgTiOz/mL)), same as 8.1.1. 9.2.2 Instruments
Spectrophotometer.
9.2.3 Analysis steps
Allowance
(6)
Take two portions of the test solution (A) and place them in two 50ml volumetric flasks respectively. Add 5ml of phosphoric acid (1+1) and 5ml of hydrogen peroxide (1+9) to one portion, dilute to the mark with water, shake to make the color developing solution. Add 5ml phosphoric acid (1+1) to the other part, dilute to the mark with water, shake well, and use it as the reference solution. On the spectrophotometer, select 2cm colorimetric blood, measure the absorbance at a wavelength of 410nm, and find the amount of titanium oxide from the working curve.
9.2.4 Drawing of working curve
Take 02.00, 4.00, 6.00, 8.00, 10.00, 12.00mlL of titanium oxide standard solution (0.1mgTi0z/mL) (Ti00~1.2mg), place them in 7 50mL volumetric flasks, add 5ml phosphoric acid (1+1) and 5ml hydrogen peroxide (1+9) to each, dilute to the mark with hydrochloric acid (1+9), shake well, and use it as the color developing solution. Take another 50mL volumetric flask, add 5ml phosphoric acid (1+1), dilute to the mark with hydrochloric acid (1+9), shake well, and use it as the reference solution. On the spectrophotometer, select 2cm colorimetric III, measure the absorbance at a wavelength of 410nm, and draw a T curve.
9.2.5 Calculation of analysis results
Calculate the percentage of titanium oxide in the sample according to formula (7): C×250/25×100%
Where: C—the amount of titanium oxide found from the working curve, g; -the mass of the sample,.
9.2.6 Allowable difference
The difference in analysis results between laboratories should not be greater than the allowable difference listed in Table 7. 570
Titanium oxide content
≥0.501.00
>1.00～~2.00
10 Determination of calcium, magnesium, manganese, potassium and sodium oxides JB/T9225--1999
10.1 Determination of calcium oxide (EDTA complexometric titration) This method is applicable to the determination of calcium oxide content above 0.10% in the sample. 10.1.1 Reagents
Nitric acid (11).
Hydrofluoric acid.
Perchloric acid.
Hydrochloric acid (1+11)
Potassium hydroxide solution (30%), stored in a plastic bottle. Ethanolamine (1+2).
Allowance difference
Ethylene monoamine tetraacetic acid disodium (EDTA) standard solution (0.005 mol/L), weigh 1.86 g EDTA into a 500 ml beaker, add about 200 ml of water, heat to dissolve, dilute with water to 1000 ml, and mix. Calcium oxide standard solution (1.0 mg CaO/ml.) Weigh 1.7848 g of calcium carbonate that has been pre-dried at 105~110°C for 12 hours and place it in a 300 ml beaker. Add about 150 ml of water, cover with surface III, and slowly drop 20 ml of hydrochloric acid (1+1) to dissolve it. Heat and boil for several minutes to drive out all carbon dioxide, cool to ambient temperature, transfer to a 1000 ml volumetric flask, dilute with water to the mark, shake and store in a dry plastic bottle. Calcein mixed indicator: weigh 0.2 g calcein, 0.1 g thymol acid, 0.4 g acridine and 20 g dried potassium sulfate, grind them in an agate mortar and mix them evenly, and store them in a brown wide-mouth bottle. 10.1.2 Standardization of EDTA standard solution
Put 10.00ml of calcium oxide standard solution (1.0mgCa0/mL) in a 300mL beaker, add about 150ml of water, add potassium hydroxide (30%) until the pH value of the solution is about 12, then add 10mL in excess, add an appropriate amount of calcein mixed indicator, and titrate with EDTA standard solution against a black background until the green light disappears and purple-red appears as the end point. The concentration (C) of EDTA standard solution is calculated according to formula (8): C (mol/1.) -
Where: V-volume of EDTA standard solution consumed during titration, mL, 56.08-amount of calcium oxide.
10.1.3 Analysis steps
(8)
Weigh 1g of sample, accurate to 0.0001g, place in platinum blood, moisten with water, add 5mL nitric acid (1+1), 3ml chlorine, 15ml hydrofluoric acid, dissolve at low temperature, evaporate and smoke until almost dry, rinse the blood wall with water, continue to evaporate until the perfluoric acid smoke is gone, remove and cool. Add 20ml hydrochloric acid (1+-11), heat at low temperature to dissolve the salt until the solution is clear, cool, transfer to a 100ml volumetric flask, dilute with water to the mark, spread with a spoon, this solution is the sample solution (B), for the determination of calcium, magnesium, manganese, potassium, sodium oxides. Pipette 20.0ml of test (B) into a 300mL beaker, add 10ml of triethanolamine (1+2), dilute with water to about 200mL, add 15mL of potassium hydroxide solution (30%), add an appropriate amount of calcein mixed indicator, and titrate calcium with EDTA standard solution (0.005mol/L) against a black background until the green fluorescence of the solution disappears and turns purple-red as the end point. 10.1.4 Calculation of analysis results
Calculate the percentage of calcium oxide in the sample according to formula (9): Ca0=cxVX56.08X100/20 ×100% .m×1000
JB/T9225---1999
Where: C----Concentration of EDTA standard solution, mol/L; V-Volume of EDTA standard solution consumed during titration, mL.56.08-Molecular weight of calcium oxide;
Sample mass, g.
10.1.5 Allowable Difference
The difference between the analysis results of laboratories should not be greater than the allowable difference listed in Table 8. Table 8
Calcium Oxide Content
0.10～0.50
≥0. 50～1. 00
≥1. 00 ~ 2. 00
>2.00~4.00
10.2 Determination of Magnesium Oxide (EDTA Complexometric Titration) This method is applicable to the determination of magnesium oxide above 0.10% in the sample. 10.2.1 Reagents
Triethanolamine (1+2).
Ammonia-ammonium chloride buffer solution (pH-10) Weigh 67.5g of ammonium chloride, dissolve it in 200ml of water, add 570ml of ammonia to dilute to 1000ml, and shake well.
Acid chrome blue K-naphthol green B1+2) mixed indicator Weigh 0.2g acid chrome blue K, 0.4g naphthol green B.30g potassium nitrate is finely ground in a mason jar and stored in a brown wide-mouth bottle. EDTA standard solution (0.005mol/L) is the same as 10.1.1.10.2.2 Analysis steps
Pipette 20.0mL test solution (B) into a 300mL beaker, add 30ml triethanolamine (1+2), shake well, let stand for 5min, and dilute with hot water to about 200ml (the solution temperature should be kept above 50C at this time). Then add 20mL ammonia-ammonium fluoride buffer solution (pH-10) and an appropriate amount of acid chrome blue K-naphthol green B mixed indicator, and use EIDTA standard solution (0.005mol/1.) to titrate the calcium and magnesium in the test solution until the test solution turns from purple-red to pure blue, which is the end point.
10.2.3 Calculation of analysis results
Calculate the percentage of magnesium oxide in the sample according to formula (10): CX(V,-V)X40.30X100/20
m×1 000
Wherein: C-concentration of EDTA standard solution, mol/L; Vi-volume of EDTA standard solution consumed when titrating calcium and magnesium, mL; volume of EDTA standard solution consumed when titrating calcium, m.40.30·molecular weight of magnesium oxide;
mass of sample, g.
10.2.4 Allowable coupons
The difference in analysis results between laboratories should not exceed the allowable difference listed in Table 9, 572
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.