HG/T 2428-1993 Determination of strontium carbonate content in celestite ore
Some standard content:
Chemical Industry Standard of the People's Republic of China
HG/T 2428 .. 93
Determination of Strontium Carbonate in Celestite Ore-15 Issued
1993-04-
Ministry of Chemical Industry of the People's Republic of China
1993-10-01 Implementation
Chemical Industry Standard of the People's Republic of China
Determination of Strontium Carbonate in Celestite Ore 1 Subject Content and Scope of Application
This standard specifies the method for determining the strontium carbonate content in celestite ore. HG/T2428-93
This standard is applicable to celestite ore products containing strontium ore, and also to strontium ore products with a strontium carbonate content of less than 80%. 2 Method Summary
The sample is dissolved in water to remove calcium sulfate, and strontium carbonate is diffused with ammonium chloride-strontium chloride solution. At pH 10, EDTA is used to complex strontium, calcium and magnesium with chrome black T-phenol green B-dazhi yellow as indicators. In the presence of sodium sulfate, excess magnesium sulfate is used to make the strontium in the EDTA complex form strontium sulfate precipitation. Excess magnesium ions are titrated with EDTA standard titration solution, and the strontium carbonate content is calculated from the magnesium consumed in the reaction. 3 Reagents and solutions
The reagents and water used in this standard, unless otherwise specified, are analytical reagents and distilled water or water of equivalent purity. 3.1 Anhydrous sodium sulfate (GB9853).
3.2 μ5% ethanol (GB 679).
3.3 Ethanol washing solution: 1+4 solution.
3.4 Ammonium chloride-strontium chloride solution, weigh 100.0g ammonium chloride (GB658) and 4g strontium chloride (SrCl26H2O) and dissolve in 200mL water, transfer to a 10001mL volumetric flask, dilute to scale with water, and mix well. 3.5 Magnesium sulfate solution: c (MgSO4) = 0.07ml/l. Weigh 8.4g anhydrous magnesium oxychloride and dissolve in 200mL water, transfer to a 100GmL volumetric flask, dilute to scale with water, shake well, 3.6 Nitrogen water (GB631): 1-+1 solution.
3.7 Ammonium chloride-ammonia buffer solution: pH ~ [0. Weigh 67.5g ammonium chloride (GBG58) and dissolve in 200mL water, add 570mL hydrogen water (GB631), dilute to 1000mL with water, and shake well. 3.8 Hydrochloric acid (GB 622): 1+1 solution.
3.9 Zinc standard solution: c(Zn)=0.02000mal/L. Weigh 1.3076g of zinc (high purity) with the surface oxide film removed, dissolve in 20mL hydrochloric acid (3.8), evaporate to 10mL after complete dissolution, cool, transfer to a 1000mL volumetric flask, dilute to scale with water, and shake. 3.10Z Sodium diaminetetraacetate (EDTA) (GB1401) standard titration solution: r(EDTA)=0.02no1/L. 3. 10. 1 Preparation
Weigh 14.8g EDTA and dissolve in 200mL water, heat to dissolve, cool, dilute to 2000mL with water, and shake. 3.10.2 Calibration
3.10.2.1 Calibration method
Use a pipette to take 20mL of zinc standard solution and place it in a 250mL beaker. Add 25mL of water, 10mL of ammonium nitride-ammonia buffer solution, 4 drops of chrome black T indicator solution, and 3 drops of violet green B-darkenol yellow indicator solution. Titrate with EDTA standard titration solution until the solution turns green as the end point, and perform a blank test at the same time.
3. 10.2.2 Calculation
The concentration of EDTA standard titration solution (c) is calculated according to formula (1): Approved by the Ministry of Chemical Industry of the People’s Republic of China on April 15, 1993 and implemented on October 1, 1993
HG/T2428-93
C(EDTA)
Wherein: c(EDTA)—actual concentration of EDTA standard titration solution, mDI/L; ti—concentration of zinc standard solution, mol/L, V, volume of zinc standard solution, mL
volume of EDTA standard titration solution, mL; V—volume of EDTA standard titration solution in blank test, mL. 3.11 Zinc-EDTA solution, weigh 21.9g zinc oxide EZn(CH,COO),·2H,O)(HG3-1098), 37.2g EDTA and dissolve in 500mL water and 100mL nitrogen water (3.6), transfer into a 1C00mL volumetric flask, dilute to the scale with water, and shake well. Pipette 10mL of the above prepared solution, add 50mL water, 10mL ammonium chloride-nitrogen water buffer solution, 4 drops of chrome black T indicator solution, and 3 drops of naphthol green B-dasanhuang indicator solution. Titrate with EDTA standard titration solution until the solution turns green. At this time, if the consumption of EDTA standard titration solution is 0.2-0.3 mL, it is sufficient. Otherwise, add measured zinc acetate or EDTA to adjust; 3.12 Chrome black T indicator solution, weigh 0.2g Chrome black T and dissolve it in 10mL ammonia water (GB631) and 40mL anhydrous ethanol (GB678). After dissolving completely, store it in a brown bottle (use period 15 days); 3.13 Naphthol green B-Dad yellow indicator solution: weigh 0.02g Naphthol green B and 0.08g Dad yellow and dissolve them in 50mL water, add 2-4 drops of ammonia water (3.6)
3.14 Neutral red (HG3-958) indicator solution, 1g/L ethanol solution. 4 Instruments and equipment
Pipette: 10ml, 20mL, 25mL, in accordance with GB12B08, Class A. 5 Sample
The sample passes through a 710um test sieve (GB6003), is dried at 105~110℃ until constant temperature, and is placed in a desiccator to cool to ambient temperature. 6 Analysis steps
6.1 Weigh 0.1~0.5g of sample (0.2~0.3g of strontium ore), concentrate to 0.0002g, and cover it in a 150ml beaker. Add 40mL of water, cover the surface blood, heat on a hot plate to a slight boil for 20~30min (stir 2~3 times), until the solution volume is about 20mL, remove it, and cool to room temperature. Wash the surface blood with 10mL of ethanol (3.2), stir the solution evenly and let it stand for 10~15min. Filter with dense filter paper, wash the beaker 4 times with ethanol washing solution (3.3), and wash the precipitate 7~8 times (each time, rinse the filter paper with about 2mL of ethanol washing solution). Wipe the mouth of the beaker with a small piece of filter paper and place it in the corresponding funnel. 6.2 Transfer the filter paper and the precipitate into a forged glass (or smooth porcelain), place it in a muffle furnace and burn it at 600℃ for 30 minutes, and the filter paper will be completely ashed. Take it out and cool it, and transfer the burning residue completely into the original beaker. 6.3 Take 20mL of ammonium nitrate-strontium chloride solution with a pipette and add it to the beaker along the wall of the cup. Cover the surface with blood, heat it on a hot plate at low temperature and boil it for 35-45 minutes, and move it frequently until small bubbles disappear and large bubbles appear. The volume of the bath liquid is 8-10mL. Remove it and cool it to room temperature. Rinse the surface III with 5mL of ethanol (3.2), stir the bath liquid evenly and let it stand for 10-15 minutes, add 1 drop of red indicator liquid, and the solution will be red (if the solution is yellow, the amount of stirring should be reduced). Filter with dense filter paper into a 100mL volume bottle, wash the beaker with ethanol washing solution (3.3) 4 times, wash the precipitate 10-12 times (each time use about 2mL ethanol washing solution to rinse around the filter paper). Dilute with water to the scale and shake. 6.4 Use a pipette to take 25mL of the solution prepared in 6.3, put it in a 250mL beaker, add 10mL zinc-EDTA solution, 10mL nitrogen water (3.6), 4 drops of chrome black T indicator, 3 drops of tea phenol green B-dextrin indicator, and titrate with EDTA standard titration solution until the solution turns bright green (ignore the reading).
Add 10mL magnesium sulfate solution and 2g anhydrous sodium sulfate, stir to dissolve, cover the surface with blood, move the beaker to the hot plate and add 2
HG/T 2428-93
heat slightly boiling for 10min, and quickly cool to room temperature with cold water. Wash the surface with 1/4 volume of ethanol (3.2) of the solution (generally 15~20mL), stir the solution evenly, and let it stand for 10~15min. Filter with dense filter paper, collect the filtrate in a 250mL beaker, wash the beaker 4 times with ethanol washing solution (3.3), and wash the precipitate 8 times (each time, rinse around the filter paper with about 2mL ethanol washing solution). 6.5 Add 10ml of nitrogen water (3.6) to the filtrate, cover the surface with blood, and heat to 40~60℃. Remove, add 3 drops of chrome black T indicator, 2 drops of phenol green B-daphne indicator solution, and titrate with FDTA standard titration solution (3.10) until the solution turns pure blue as the end point, and record the volume of EDTA standard titration solution consumed.
Perform a blank test at the same time as the sample determination. bzxz.net
Description of analysis results
The content of strontium carbonate (SrCO) (X) expressed as mass percentage is calculated according to formula (2). X = VL-Y):cX 0. 1476
m X 25/100
Wu City:c-
Actual concentration of EDTA standard titration solution, mal/L; V1: Volume of EDTA standard titration solution in blank test, InL; V.
8Allowance difference
Volume of EDTA standard titration solution, mL; Mass of sample, ;
Carbon strontium mass equivalent to 1.00nEDTA standard titration solution [c (EDTA) = 1.000mal/LJ, expressed in grams.
The arithmetic mean of the parallel determination results is the determination result, and the absolute difference of the parallel determination results should not be greater than the value shown in the table below. Strontium carbonate (Srco,> content
>10.0--30.0
>30.00--50.00
Additional remarks:
This standard is proposed by the Ministry of Science and Technology of the Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Chemical Industry Design and Research Institute of the Ministry of Chemical Industry. The Chemical Industry Design and Research Institute of the Ministry of Chemical Industry is responsible for drafting this standard. The main drafters of this standard are Hua Lihua and Zhang Xiaomei. Tolerance
People's Republic of China
Chemical Industry Standard
Determination of strontium carbonate content in celite ore HG/T 2428--93
Editorial Department of Chemical Industry Standardization
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First Edition: 1993 10 Sheets First Printing Number: 1--5 00
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HG_T 242893
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