HG 2957.10-1984 Determination of total iron content in alum ore - Sulfosalicylic acid photometric method
Some standard content:
Scope of application
National Standard of the People's Republic of China
Alunite ores-Determination of total iron content--Sulphosalicylic acld photometric methodUDC 549.762:543
-42 : 546.72
GB4581.10-84
This standard specifies the determination of 10.10~10.00% iron oxide content in alunite ores by sulfosalicylic acid complex photometric method. 2Related standards
GB4581.1-84 "General rules for analysis of alunite ores". GB4581.2-84 "Methods for taking and preparing analysis samples of alunite ores". 3 Method Summary
The sample is melted with sodium hydroxide and sodium peroxide, and then acidified after leaching in water. In an ammonia medium with a pH of 8.5 to 11.8, iron ions form a yellow complex with sulfosalicylic acid. At a wavelength of 430 nanometers, the gram molecular absorption coefficient is 5.32×10, and iron oxide conforms to Beer's law in the range of 0 to 0.9 mg/100 ml. Www.bzxZ.net
4 Instrument
Spectrophotometer: 430 nanometers in length, 1 cm colorimetric blood. 5 Reagents and solutions
5.1 Sodium hydroxide (GB 629-81).
5.2 Sodium peroxide.
5.3 Hydrochloric acid (GB622-77) (specific gravity 1.19). 5.4 Nitric acid (GB 626-78) (specific gravity 1.42), 5.5
Ammonia water (GB631-77) (specific gravity 0.90): 1+15.6Sulfosalicylic acid (HG3-991-81): 25% (filtered and placed in brown bottle). 5.7
Iron wire.
5.B Iron standard solution
5.8.1 Weigh 1.4297 g of iron wire (5.7) and place it in a 150 ml beaker 1, add 20 ml of aqua regia, and heat to dissolve. After cooling, transfer to a 1000 ml volumetric flask, dilute to the mark with water, and shake to make a hook. This solution contains iron oxide per ml 1.000 mg. 5.8.2 Pipette 100 ml of the free solution (5.8.1) into a 1000 ml volumetric flask, dilute to the mark with water, and shake well. This solution contains 0.1000 mg of iron oxide per ml. 6 Determination procedures
6.1 Drawing of standard curve
Use a microburette to place 0, 1.00, 2.00, 3.00, ...··9.00 ml of the iron standard solution (5.8.2) into a 100 ml volumetric flask. Issued by the National Bureau of Standards on July 20, 1984
. Implemented on June 1, 1985
GB 4581.10.--84
Into each volumetric flask, add 12 ml of salicylic acid solution (5.6) and shake for about 10 minutes. Add ammonia solution (5.5) drop by drop until the solution turns yellow and no longer darkens, then add 10 ml. Dilute with water to the scale, shake, and measure the extinction value with a 1 cm colorimetric scale at a wavelength of 430 nm on a spectrophotometer. Use the concentration of iron oxide as the horizontal axis and the corresponding extinction value as the vertical axis to draw a standard curve. 6.2 Sample analysis
Weigh 0.2-0.5 g of sample silver, add a small amount of anhydrous ethanol to wet the sample, add 4 g of sodium hydroxide (5.1), and then cover with 0.5 g of sodium peroxide (5.2), place in a muffle furnace, heat from low temperature to 700°C, melt for 15 minutes, take out and cool, put in a 150 ml beaker, add 50 ml of hot water, cover the surface with blood, heat the molten block, and use hot water Wash out the crucible. Add 15 ml of hydrochloric acid solution (5.3) and boil for 15 minutes. Remove and cool, transfer to a 250 ml volumetric flask, dilute with water to the mark, and shake. Dry filter. Pipette 10-50 ml of the filtrate into a 100 ml volumetric flask, and the following operations are the same as the drawing of the standard curve (6.1). 7 Expression and calculation of results
The percentage content (xin) of iron oxide (Fez (3) is calculated according to the following formula: V
×10-3
Where: G1--heavy oxygen content of iron oxide in the sample solution found on the standard curve, g; -total volume of the measured solution, ml,
V-volume of the sample solution, ml
W-weight of the sample, g.
8 Tolerance
Fe content, %
0.10~t.00
1.01 -- 10,00
Additional Notes:
Diameter tolerance (absolute value), %
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 Research Institute of the Ministry of Chemical Industry. This standard was drafted by the Chemical Industry Research Institute of the Ministry of Chemical Industry, and the main author of this standard is Cheng Maomei.
From the time this standard is implemented, the original Ministry of Chemical Industry standard HG1-353-66 "Uniform Analysis Method of Alum Stone" will be invalid. 23
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