JB/T 9220.4-1999 JB/T 9220.4-1999 Chemical analysis method of acidic slag from foundry cupola furnaces - Sodium arsenite-sodium nitrite volumetric method for determination of manganese monoxide content JB/T9220.4-1999 Standard download decompression password: www.bzxz.net

JB/T9220.4--1999
This standard is a revision of JB/Z281.4--87 "Chemical analysis method of acidic slag of foundry cupola furnace - determination of manganese oxide content by sodium arsenite-sodium nitrite volumetric method". During the revision, editorial changes were made to the original standard, and the main technical content remained unchanged. This standard replaces JB/Z284.4--87 from the date of implementation. This standard was proposed and managed by the National Technical Committee for Foundry Standardization. The drafting units of this standard are: Shanghai Diesel Engine Factory, Nanchang Diesel Engine Factory, Guiyang Foundry, Shenyang Foundry, Shanghai Tractor Engine Factory, Huafeng Steel Factory, Wuxi Diesel Engine Factory, Changzhou Diesel Engine Factory, etc. The main drafters of this standard are: Wang Zhihan, etc. www.bzxz.net
Standard of the Machinery Industry of the People's Republic of China
Chemical analysis methods for acid slay of cupola---Determination of manganous oxide by volumetricmethod using sodium arsenite-sodium nitrite1Scope
JB/T 9220.4
Replaces JB/Z284.--87
This standard specifies the determination of manganous oxide in chemical analysis methods. Determination range: 0.20%~10.00%. This standard is applicable to the analysis of the composition of acid slag of cupola. 2Test conditions
The sample is dissolved with sulfur, nitric and phosphorus mixed acid, silicon is evaporated with hydrofluoric acid, manganese is oxidized to seven valence with ammonium persulfate using silver nitrate as catalyst, and titrated with sodium arsenite-sodium nitrite standard solution.
3 Reagent preparation
3.1 Sulfuric acid-nitric acid-phosphoric acid mixture: Sulfuric acid (density 1.84g/ml.) + nitric acid (density 1.42g/mL) + phosphoric acid (density 1.70g/ml.) + water (90+200+90+600) 3.2 Hydrofluoric acid (density 1.15g/mL).
3.3 Silver nitrate solution (1.7%).
3.4 ​​Ammonium persulfate solution (20%).
3.5 Sodium chloride solution (1%).
3.6 Manganese oxide standard solution: Weigh 0.3873g electrolytic manganese (99.95% or more) and place it in a 250ml beaker, add 20ml nitric acid (1+3), heat to dissolve, boil to drive out nitrogen oxides, cool and transfer to a 1000mL volumetric flask, dilute to scale with water, and mix well. This solution contains 0.5mg manganese oxide in 1ml.
Note: Electrolytic manganese treatment method: Place electrolytic manganese in sulfuric acid (5+95) and heat to clean it. When the surface manganese oxide (brown) is cleaned, take it out and wash it repeatedly with water. Then wash it in anhydrous ethanol for 4-5 minutes. Take it out and dry it in a dryer before use. 3.7 Sodium arsenate-sodium sulfite standard solution 3.7.10.025N, weigh 1.25-1.30g arsenic trioxide, put it in a 600ml beaker, add 25ml sodium hydroxide solution (15%). Heat at low temperature to dissolve, dilute with water to about 100ml, add sulfuric acid (1+1) to make the solution acidic, and add 2-3ml in excess, then neutralize it with sodium carbonate solution (15%) to neutrality, then add 0.85g sodium sulfite. If there is any confusion, filter it, dilute it with water to 2000ml and mix it well. This solution is used to determine the sample containing more than 2% manganese monoxide. 3.7.2 0.0125N, transfer 100.00ml. Sodium arsenite-sodium nitrite standard solution (3.7.1). Place it in a 200ml volumetric flask, dilute to the mark with water, and mix. This solution is used to determine the sample containing less than 2% manganese monoxide. 3.7.3 Determination of T value: Transfer three portions of manganese monoxide standard solution (3.6) (its content should be close to the manganese monoxide content in the sample) and place them in 250mL flasks respectively. The following is carried out according to 4.2.1 to 4.2.3. The number of milliliters of sodium arsenate-sodium nitrite standard solution consumed in the titration of the manganese monoxide standard solution shall not exceed 0.05ml. The average value shall be taken. Approved by the State Bureau of Machinery Industry on June 24, 1999 434
2000.01-01 implementation
JB/T 9220.4
The titer of sodium arsenite-sodium nitrite standard solution on manganese monoxide is calculated according to formula (1): T
Wherein: T
The titer of sodium arsenite-sodium nitrite standard solution on manganese monoxide, g/ml; Vi. The volume of manganese monoxide standard solution transferred, mL. The amount of manganese monoxide contained in the manganese monoxide standard solution·g/ml. V
The average volume of sodium arsenite-sodium nitrite standard solution consumed during calibration, m4 Analysis steps
4.1 Sample amount
Weigh the sample amount according to Table 1.
Manganese oxide content, %
0.20~2.00
>2. 00--10. 00
4.2 Determination
Amount·g
4.2.1 Place the sample (4.1) in a 250ml conical flask, moisten the sample with a small amount of water, add 25ml. sulfuric acid-nitric acid-phosphoric acid mixed acid (3.1), heat at low temperature to dissolve, add 6-8 drops of hydrofluoric acid (3.2), after dissolution, boil for 2-3 minutes to remove nitrogen oxides and silicon volatilization. Note: When dissolving, be sure to drive out all nitrogen oxides, otherwise it will cause permanganate reduction. 4.2.2 Add 20ml water, 5ml silver nitrate solution (3.3), and 15ml. ammonium persulfate solution (3.1) to the solution, heat to boiling and boil for 1 minute, remove and let stand for 2 minutes, and cool to room temperature in running water. Note: The boiling time should not be too long, and the storage time after boiling should not be too long, especially for samples with high content. 4.2.3 Add 5mL of sodium fluoride solution (3.5) and immediately titrate with sodium arsenite-sodium nitrite standard solution (3.7) until the red color disappears. 5 Calculation of analysis results
Calculate the percentage of manganese monoxide according to formula (2): MnO
Where: T
6 Tolerance
×100%
Titration degree of sodium arsenite-sodium nitrite standard solution on manganese monoxide, g/ml: Volume of sodium arsenite-sodium nitrite standard solution consumed in titration, ml; Sample volume·g.
The difference between the analysis results in the experimental space should not be greater than the tolerance listed in Table 2. When calibrated with standard samples, the deviation should not exceed 1/2 of the tolerance listed in Table 2.
Manganese oxide content
0.20~~1.00
1.00 -~2.00
Manganese oxide content
≥2.00 4.00
4.00~~ 10.00
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