HG 2957.4-1984 Determination of sulfur content of sulfate in alum stone ore Barium sulfate gravimetric method HG2957.4-1984 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Alunite ores-Determinatlon of sulphur content for sulphateBarium sulphate grayimetrie method
Alunite ores-Determinatlon of sulphur content for sulphateBarium sulphate grayimetrie methodScope of application
UDC 548.762
GB 4581.484
fs7. 4 -1fe9
This standard specifies the determination of 5.00-30.00% sulphate sulfur content of alunite ores by the sulphur lock weight method. 2 Related standards
GB4581.1-84 "General rules for analysis of alunite ores". GB4581.2-84 "Alum ore analysis sample collection and preparation method" 3 Method summary
The sample is leached with alkali solution, and the sulfate sulfur is transferred to the solution. It is precipitated with chloride in an acidic medium and weighed. Calculate the sulfate sulfur content.
4 Reagents and solutions
4.1 Hydrochloric acid (GB 622-77) (specific gravity 1.19): 111. 4.2 Hydrochloric acid: 1+100. bzxz.net
4.3 Sodium hydride (GH 629--81): 1N. 4.4 Sodium hydroxide: 1%.
4.5 Barium chloride (GB652-78): 5% (filter before use). 4.6 Base (HCB 3089--59): 0.1%. 4.7 Silver nitrate (GB670-77): 1% 0.5N nitric acid solution. 5 Determination procedure
Weigh 0.4 g of the sample and put it in a 100-liter beaker. Add 30 liters of sodium hydroxide solution (4.3), shake the sample, and cover it. Heat to boiling and place it on a magnetic stirrer, stir it for 20 minutes at a low temperature, remove it and cool it. Then filter it with slow filter paper, collect the filtrate in a 100-liter beaker, transfer the line to a jar 1 with sodium hydroxide solution (4.4), wash it 5 times, and finally wash it 10 times with hot water (about 5 liters of water each time). Dilute the volume to 25 ml, add 1 to 2 drops of methyl% indicator (4.6), adjust the solution to red with 1 ml of ethyl acetate solution (4.1), and then add 3 ml of excess. Cover the surface, heat the solution to, remove it, and drip the heated solution under constant stirring. Add 10-12 liters of barium chloride solution (4.5). Keep warm for 2 hours, remove and age for 3-4 hours or overnight. Filter with dense quantitative filter paper, wash the precipitate twice with hydrochloric acid solution (4.2), transfer the washed precipitate to a funnel, and then wash with warm water to remove chloride ions (detect with silver nitrate solution). Put the precipitate together with the precipitate into a hot porcelain. After drying and ash formation, place it in a furnace at 800℃ for 1 hour, cool it and weigh it. Weight, and then burn to constant weight. National Bureau of Standards 1984·07-20 Issued
1985-06-01 Implemented
Result Expression and Calculation
GB4581.4—84
The percentage content (X) of sulfate sulfur (SO) is calculated according to the following formula: X2-
Where:
Tolerance
(G1-G2) × 0.3430
Weight of precipitate and porcelain crucible after burning, g; weight of porcelain crucible, g:
Weight of sample, g;
Factor for converting sulfuric acid to sulfuric acid.
Content of sulfuric acid in sulfate, %
5.00~10.00
10.01-20.00
20.01~30.00
Additional instructions
Tolerance (absolute), %
This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China and is under the jurisdiction of the Chemical Industry Design and Research Institute of the Ministry of Chemical Industry. This standard is drafted by the Chemical Industry Design and Research Institute of the Ministry of Chemical Industry. The main drafter of this standard is Cheng Maomei.
From the date of implementation of this standard, the original Ministry of Chemical Industry Standard HI1-353-66 "Alumite System·Analysis Method" shall be invalid.
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