JB/T 9220.6-1999 Chemical analysis of acidic slag from foundry cupola - Determination of calcium oxide content by DDTC separation and EGTA volumetric method
Some standard content:
3B/T9220.6
This standard is a revision of JB/Z284.6-87 (Chemical analysis method of acidic slag of foundry cupola furnace - Determination of calcium oxide content by DIYTC separation and EGTA volumetric method). During the revision, editorial changes were made to the original standard, and the main technical content remained unchanged. This standard replaces JB/Z284.6-87 from the date of implementation. This standard was proposed and approved by the National Technical Committee for Foundry Standardization. The drafting units of this standard include: Shanghai Diesel Engine Factory, Nanchang Diesel Engine Factory, Guiyang Foundry, Shenyang Foundry), Shanghai Tractor Engine Company, Huafeng Iron and Steel Factory, Wuxi Diesel Engine Factory, Changzhou Diesel Engine Factory, etc. The main drafters of this standard include: Wang Zhihan, etc. 440
1 Scope
Standard of the Machinery Industry of the People's Republic of China
Chemical analysis methods for acid slay of cupola-Determination of calcium oxide by DDTCseparation process and EGTA volumetric methodJB/T 9220.6:1999
Replace JB/Z 284.6-87
This standard specifies the determination of calcium oxide in chemical analysis methods. Determination range: 15.00%~45.00%. This standard is applicable to the analysis of the composition of acid slag of cupola. 2 Test conditions
The sample is dissolved by hydrochloric acid and hydrofluoric acid to evaporate silicon. Nitric acid and perchloric acid are used to smoke and drive off fluoride ions. Under acidic conditions of pH 6.5, copper reagent is used to precipitate and separate interfering elements such as iron, aluminum, manganese, titanium, chromium, bismuth, and rare earth. In a sodium hydroxide medium of pH 12.5-13.0, triethanolamine is used to mask the iron and aluminum ions remaining in the filtrate after precipitation and separation, and a calcium indicator is added, and the solution is titrated with an EGTA standard solution. 3 Reagent preparation
3.1 Hydrochloric acid (density 1.19 g/mL).
Hydrochloric acid (1+1).
3.3 Hydrofluoric acid (density 1.15 g/ml.).
Nitric acid (density 1.42 g/mL).
Perchloric acid (density 1.67 g/mL).
Ammonium hydroxide (1+1).
. Sodium ethyl thiocarbamate (copper reagent, DDTC) solution (20%) is prepared when used. = Ethanolamine (1+1).
3.9 Propylene glycol (1+1). bzxz.net
Sodium hydroxide solution (20%).
Calcium indicator: 1g calcium indicator is mixed with 100g sodium chloride and ground evenly, then dried for use. 3.114
3.12 Calcium oxide standard solution: Weigh 0.8924g calcium carbonate (superior purity) dried at 105°C to a constant weight, place in a 600ml beaker, add 100ml water, cover with Table III, slowly drip hydrochloric acid (3.2) along the beaker until completely dissolved, heat, boil slightly for a while, cool, transfer to a 1000ml volumetric flask, dilute with water to the mark, and mix. This solution contains 0.5mg calcium oxide in 1mL. 3.13 Ethylene glycol bis(α-aminoethyl) ether tetraacetic acid (EGTA) standard solution 3.13.10.01M, weigh 3.8035g EGTA and dissolve it in water, drip sodium hydroxide solution (3.10) to dissolve it completely, transfer to a 1000ml volumetric flask, dilute with water to the mark, and mix evenly. 3.13.2 Determination of T value: Take three portions of 25.00ml calcium oxide standard solution and place them in 250ml conical flasks respectively. The following shall be carried out according to 4.3.1 to 4.3.4. The number of milliliters of FGTA standard solution consumed by titrating three portions of calcium oxide standard solution shall not exceed 0.05ml. The average value shall be taken.
Approved by the State Machinery Industry Bureau on June 24, 1999 and implemented on January 1, 2000
Conduct air self-driving test at the same time.
JB/T 9220.6--1999
Calculate the titer of EGTA standard solution to calcium oxide according to formula (1): V,C
Wherein: T--The titer of EGTA standard solution to calcium oxide, g/mI.; V,--The volume of calcium oxide standard solution pipetted, mL; (\-The amount of calcium oxide in calcium oxide standard solution, g/ml; V.--The average volume of EGTA standard solution consumed during calibration, mLV. ...---The volume of EGTA standard solution consumed in blank test, mL. 4 Analysis steps
4.1 Sample amount
Weigh 1.0000g sample.
4.2 Blank test
Carry out a blank test with the sample.
4.3 Rotation
4. 3.1 Place the sample (4.1) in a 250ml polytetrafluoroethylene beaker, wet the sample with a small amount of water, add 20mL hydrochloric acid (3.1) and 10ml hydrofluoric acid (3.3), heat at low temperature to dissolve, remove and cool slightly after most of the sample has dissolved, add 5mL nitric acid (3.4) and 10ml perchloric acid (3.5) and heat until thick perchloric acid smoke is emitted for 5~10 minutes, remove and cool, rinse the inner wall with water, add 2ml perchloric acid (3.5) and continue heating until thick white perchloric acid smoke is emitted until 23ml of solution remains in the cup. Note: The temperature of the heated decomposition sample should not be too high, and the heating decomposition time generally takes about 30 minutes. 4.3.2 Remove and cool, rinse the wall of the cup with water, add 20mL hydrochloric acid (3.2), heat to dissolve the salts, remove and cool, Transfer the solution to a 100ml volumetric flask, dilute to the mark with water, and mix. Note: 1.3.1 and 1.3.2 are the same as the analytical steps for determining the amount of aluminum oxide. The diluted solution can be used for aluminum, calcium, and magnesium system determination. 4.3.3 Transfer 25.00ml of the test solution to a 100mL steel volumetric flask, add 25ml of water, adjust the pH to 5-6 with ammonium hydroxide (3.6) and hydrochloric acid (3.2) (use a small piece of pH test paper to check the pH value), add 10ml of copper reagent solution (3.7), dilute to the mark with water, and mix. Let stand for 2h, and dry filter.
Note: This filtrate can be used for calcium and magnesium system determination. 4.3.4 Transfer 25.00ml of the filtrate to a 250mL conical flask, add 5ml of triethanolamine (3.8), shake the spoon to place Place. Add 5 ml of triol (3.9). 10 mL of sodium hydroxide solution (3.10) and calcium indicator (3.11) are titrated with EGTA standard solution (3.13) until the red color changes to blue.
5 Calculation of analysis results
Calculate the percentage of calcium oxide according to (2): TX(V.-V2
Where: T----the titration degree of EGTA standard solution on calcium oxide·g/mL; V-the volume of EGTA standard solution consumed in titration, mL; V-the volume of FGTA standard solution consumed in air test, mL; .-the amount of sample taken.
6 Tolerance
(2)
The difference in analysis results between laboratories should not exceed the tolerance listed in Table 1. When calibrating with standard samples, the deviation should not exceed 1/2 of the 442
tolerance listed in Table 1.
Calcium oxide content
15.00~25.00
25. 00~35. 00
>35. 00~45. 00
JB/T 9220.6-.1999
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