GB/T 14949.3-1994 Chemical analysis methods for manganese ores - Determination of barium oxide content
Some standard content:
National Standard of the People's Republic of China
Chemical analysis method of manganese ore
Determination of barium oxide content
Manganese ores--Determination of barium oxide content This standard is equivalent to IS0548-1981 "Chemical analysis method of manganese ore 1 Subject content and scope of application
This standard specifies the determination of barium oxide content by barium sulfate gravimetric method. GB/T 14949.3
Determination of barium oxide content by barium sulfate gravimetric method". This standard is applicable to the determination of barium oxide content in manganese ore. Determination range: 0.1%~10%. 2 Method summary
The sample is treated with hydrochloric acid, nitric acid and sulfuric acid. Filter to separate barium from most coexisting elements such as manganese and iron. The residue is desiliconized with hydrofluoric acid. Melt with a mixed flux of potassium carbonate and sodium carbonate. Leach the molten block with water and filter. Dissolve barium carbonate in hydrochloric acid chips, precipitate barium in the form of sulfuric acid, filter and burn until the barium sulfate is constant.
When strontium is present, convert barium sulfate into barium carbonate, and dissolve barium carbonate in hydrochloric acid to precipitate in the form of barium chromate. Filter and burn until the amount of barium chromate is constant.
3 Reagents
3.1 Anhydrous sodium carbonate.
3.2 Mixed flux: anhydrous sodium carbonate and anhydrous potassium carbonate (1+1), grind and mix well. 3.3 Hydrochloric acid (pl.19g/mL).
3.4 Hydrochloric acid (1+1).
3.5 Hydrochloric acid (1+3).
Sulfuric acid (1+1).
Sulfuric acid (1+4).
Sulfuric acid (1+99).
Nitric acid (ol.42g/mL).
Hydrofluoric acid (ol.14g/ml.).
Hydrogen peroxide solution (30%).
Ammonium acetate solution (600 g/L)
Ammonium acetate solution (300 g/L).
Ammonium acetate solution (6 g/L).
Silver nitrate solution (2 g/L).
Nitrogen water (1+1).
Sodium carbonate solution (20 g/L).
3. 18Methyl orange solution (1 g/L.).
Approved by the State Administration of Technical Supervision on January 18, 1994 and implemented on October 1, 1994wwW.bzxz.Net
3.19Ammonium dichromate solution (50) g/L). 4 Equipment
Common laboratory equipment and
4.1 Platinum or porcelain crucible.
GB/T 14949.3--94
4.2 Muffle furnace: The temperature can be controlled within 1000C. 5 Sample
The sample should pass through a 0.100mm sieve and be air-dried under laboratory conditions. 6 Analysis steps
6.1 Sample quantity
Weigh 0.5-2g of sample (when the sample contains less than or equal to 1% of oxide, weigh 2g; when greater than 1%, weigh 1g; when greater than or equal to 10%, weigh 0.5g), accurate to 0.0001g. Weigh the sample at the same time as the determination, and determine the mass percentage of wet water (A). When calculating the barium oxide result, the result (mass percentage) should be multiplied by the conversion factor (K), which is the mass percentage of barium oxide determined in the completely dry sample. Conversion factor (K) = 100-A
6.2 Blank test
Perform a blank test with the sample.
6.3 Determination
6.3.1 Place the sample (6.1) in a 300mL beaker, add 15mL hydrochloric acid (3.3), cover with blood, heat at low temperature to dissolve for 20min, add 5mL nitric acid (3.9), heat to a solution volume of about 5mL, remove, and cool slightly. Add 10ml sulfuric acid (3.6), heat and evaporate until white smoke appears, remove, and cool. Add 100mL hot water, heat to boiling to dissolve soluble salts, and place at room temperature for 2h. Filter with dense filter paper, wash the beaker with sulfuric acid (3.8), wash the precipitate and filter paper 5~~6 times, and then wash with hot water 2~3 times. Discard the filtrate. 6.3.2 Move the residue and filter paper into a platinum crucible, dry and ash, burn in a muffle furnace at 800℃, take out, cool, moisten the residue with 2-3 drops of water, add 1-2 drops of sulfuric acid (3.6), add about 10mL of hydrofluoric acid (3.10), heat at low temperature to evaporate until white smoke appears, take out, and cool. Add 5-6mL of hydrofluoric acid (3.10), continue to evaporate to dryness, and then heat until the white smoke disappears. Add 4-6g of mixed flux (3.2) into the platinum crucible, cover it, and melt it at 900-1000℃ for 10min. Take it out, cool it, place the crucible in a 500mL beaker containing 100mL of hot water, add 2-3mL of hydrogen peroxide solution (3.11), heat to boiling, and keep it for 10-15min. Wash the beaker and the lid, clean them with hot water, boil the solution, remove them, wait for the precipitate to settle, filter them with dense filter paper, and wash the precipitate and filter paper with hot sodium carbonate solution (3.17) until there is no sulfate ion [take a small amount of filtrate, acidify it with hydrochloric acid (3.4), boil it until bubbles appear, and then add 10% sodium chloride solution to check], discard the filtrate. Use hot hydrochloric acid (3.5) containing a small amount of hydrogen peroxide solution (3.11) to dissolve the precipitate in the original beaker (cover the funnel with a cover of Table IIIL to prevent splashing due to intense reaction), and wash the filter paper 5 to 6 times with hot water. 6.3.3 Dilute the solution to 250 mL, heat and boil for 5-10 min, add 1-2 drops of methyl orange solution (3.18), neutralize with ammonia water (3.16) until the test solution just turns yellow, and immediately adjust with hydrochloric acid (3.4) until it just turns red, add 2 mL of hydrochloric acid (3.3), heat the solution to boiling, slowly add 10 mL of sulfuric acid (3.7) to the hot solution while stirring, heat to boiling again, and keep it at a slight boil for 15-20 min. Remove and let stand for more than 12 hours. Filter with dense filter paper containing a small amount of pulp, wipe the beaker with a small piece of filter paper, and transfer all to the filter funnel, wash with sulfuric acid (3.8) until there is no fluoride ion [check with silver nitrate solution (3.15)]. 6.3.4 When the sample contains no more than 0.5 mg of lead, wash the precipitate 6 to 8 times with hot ammonium acetate solution (3.12), and then wash it 3 to 4 times with hot water (when the sample contains more than 0.5 mg of lead, lead removal measures must be taken). 6.3.5 Transfer the filter paper and precipitate into a constant amount of platinum, incinerate at 750 to 800 °C for 30 min after ashing. Weigh and repeat the calcination until K22
GB/T 14949.3 ---94
If the calcined residue has color, melt it with 0.3 to 0.4 g of anhydrous sodium carbonate (3.1), cool the melt, dissolve it in hydrochloric acid (3.5), and repeat the precipitation of sulfuric acid lock according to 6.3.3. 6.3.6 When the ore contains strontium, place the filter paper and sulfate precipitate in platinum, dry, ash, burn at 600-700C, cool, then add 3g of anhydrous sodium carbonate (3.1), cover the platinum crucible, and melt at 900-1000C for 10min. Take out. After cooling, move the crucible into a 400mL beaker containing 100mL of hot water, heat to boiling, and keep for 10-15min. After the molten mass overflows, take it out of the beaker and cover it, and wash it with hot water. Heat the solution until the precipitate condenses and filter it with slow filter paper. Wash the precipitate and filter paper several times with hot sodium carbonate solution (3.17), and discard the filtrate. Dissolve the precipitate on the filter paper 1 in the beaker with 20mL of hydrochloric acid (3.5), and wash it with hot water. Add water to a volume of 100 mL, then drop ammonia (3.16) to adjust the acidity of the solution to about pH 6.5 [detected with pH test paper]. Add 10 mL of ammonium acetate solution (3.13), heat the solution to boiling, add 10 mL of ammonium dichromate solution (3.19) dropwise while stirring, and place on a low-temperature electric hot plate for 1 hour to allow the precipitate to condense. Filter with dense filter paper containing a small amount of filter paper pulp, wipe the beaker with a small piece of filter paper, and transfer all the precipitate and filter paper to the filter bucket. Wash the beaker and filter paper with ammonium acetate solution (3.14) until the yellow color of the filter paper disappears. Put the precipitate and filter paper into a constant amount of platinum, dry, ash, and burn at 750~～800℃ for 30 minutes, and repeat the burning until constant. If the residue is green, burn the precipitate again to constant weight under the condition of increasing air contact. 7 Calculation of results
The mass percentage of barium oxide is calculated as follows: Ba0(%) (m=m)× 100 × 100 ×Km
Wherein:
The mass of barium sulfate (barium chromate) after calcination, gni
f(0.6570 or 0.6052)
The mass of barium sulfate (barium chromate) in the blank test, g; The mass of the sample, g;
The coefficient of sulfuric acid (barium chromate) converted to barium oxide; The coefficient of barium sulfate converted to barium oxide;
0.6052Coefficient of conversion of chromate lock to oxide lock; -Conversion coefficient of barium oxide content in completely dry sample, K
8Permissible difference
The difference of analysis results between laboratories shall not be greater than the permissible difference listed in the following table. Barium oxide content
0.10~0.30
>0. 30 ~~0. 50
>0. 50~1. 00
1. 00~~ 5. 00
>5.00~10.00
>10.00~20.00
Permissible difference
Additional instructions:
GB/T14949.3-94
This standard was proposed by the Ministry of Metallurgical Industry of the People's Republic of China. This standard was drafted by the Mineral Geology Research Institute of China National Nonferrous Metals Industry Corporation and the Changsha Research Institute of Mining and Metallurgy of the Ministry of Metallurgical Industry. The main drafters of this standard are Wu Aihua, Huang Baogui, Chen Ziruo and Cao Shitiao.
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