HG 2957.8-1984 Determination of total sulfur content of alum stone ore Barium sulfate gravimetric method HG2957.8-1984 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Determination of total sulphur content in alunite ores
Barium sulphate gravimetric method
Alunite ores---Determination of total sulphur content--Barium sulphate gravimetrlc method1 Scope of application
This standard specifies the determination of 5.00-30.00% gold sulphur in alunite ores by the sulphuric acid lock gravimetric method. 2 Related standards
G14581.1-84 "General Rules for Analysis of Alunite Ores". CB4581.2—84 "Alunite Ore Analysis Sample Collection and Preparation Method" 3 Method Summary
UDC549.762:543
.21:546.22
GB4581.8--84
The sample is melted with sodium oxide and sodium carbonate, and the sulfide, elemental sulfur and sulfate are all converted into soluble sulfate. After water leaching, it is precipitated in an acidic medium with old barium chloride, burned and weighed. Calculate the total sulfur content. 4 Reagents and solutions
4.1 Anhydrous sodium chalcopyrite (G13639--77). 4.2 Sodium carbonate: %.
4.3 Sodium peroxide.
4.4 Sodium peroxide-sodium carbonate mixed flux: 3+1 (mixed and stored in the dryer). 4.5 Salt (GB 622 77) (Bia 1.19): 1+1. 4.6 Hydrochloric acid: 1+100
4.7 Hydrogen orange (HGB 3089-59): 0.1%. 4.8 Ethanol (GB 678-78).
4.9 Silver nitrate (GB670.-77): 1% D.5N nitric acid solution. 4.10 Sodium chloride (GB652-78): 5% (filter before use). 5 Determination procedure
Weigh 0.4g of sample, add 3g of mixed melting (4.4), after mixing, cover with 1g of flux (4.4), place in a muffle furnace, from low temperature to 600-650℃, melt for 6-10 minutes, take out and cool, put in a 250ml beaker, add 100ml of hot water, cover the surface, heat out the molten block, wash out with hot water. If the solution turns green, add a few drops of anhydrous glycol (4.8). Put the beaker on the hot plate, boil for a while, wait for a large After part of the precipitate settles, filter it with medium-speed filter paper. Collect the filtrate in an old 400 ml beaker. Wash the beaker 4 to 5 times with hot sodium carbonate solution (4.2), precipitate more than 10 times, add 1 to 2 drops of basal orange indicator solution (4.7) to the filtrate, half cover the surface III, quickly neutralize the solution with hydrochloric acid solution (4.5) until it turns red, and then add 4 ml in excess. Dilute with water to about 300 ml. Boil the solution for 1 to 2 minutes and remove it. Under constant stirring, add 10 to 12 ml of heated chloride solution (4.10). Keep warm for 2 hours, remove and age for 3 to 4 hours or let it stand overnight. Use dense quantitative filtration National Bureau of Standards 1984-07-20 Issued
1985-06-01 Implementation
GB 4581.8—84
Filter with paper, wash the precipitate twice with hydrochloric acid solution (4.6) and transfer the precipitate to a coagulation bucket, then wash with warm water to make sure there is no chloride ion [check with silver nitrate solution (4.9)].
Put the precipitate together with the filter paper in a constant weight porcelain amber, dry it to asheen, burn it in a furnace at 800℃ for 1 hour, cool it out and weigh it, and burn it to constant weight again.
Expression and calculation of results
The percentage content (X) of total sulfur (S(),) is calculated according to the following formula: Xa=bzxz.net
Where: G
Tolerance
(G1 - (G2) × 0.3430
Weight of precipitate and porcelain crucible after calcination, g: Weight of porcelain crucible, g:
Weight of sample, g.
Total sulfur content, %
6. 00 - 10.00
10.0120.00
20.01~30.00
Additional remarks:
Tolerance (absolute value), %
This standard was proposed by the Ministry of Chemical Industry of the People's Republic of China and was drafted by the Chemical Industry Design and Research Institute of the Ministry of Chemical Industry. The drafter of this standard is Cheng Maomei.
From the date of implementation of this standard, the original standard HG1-353-66 of the Ministry of Chemical Industry "Alum Stone System-Analysis Method" will be invalid. 19
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