GB/T 4324.13-1984 Chemical analysis of tungsten - Determination of calcium content by glyoxal bis(2-hydroxyaniline) photometric method GB/T4324.13-1984 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Chemical analysis method of tungstenbZxz.net
Methodsfor chemical analysisof tungstenThe glyoxal bis (2-hydroxyanil)photonetricmethod for the determination ofcalcium content
UDC 669.27:543
42 :546.41
GB4324.13—84
This standard is applicable to the determination of calcium content in tungsten powder, tungsten bar, tungsten trioxide, tungstic acid and ammonium paratungstate. Determination range pressure: 0.0007～0.025%. This standard complies with GB1467-78 "General Principles and General Provisions of Chemical Analysis Methods for Metallurgical Products". 1 Method Summary
After the sample is chlorinated to separate the main tungsten, the residue is leached with hydrochloric acid. In an alkaline medium, calcium glyoxal bis(2-hydroxyaniline) forms a red complex, which is extracted with n-pentanol and its absorbance is measured. 2 Reagents
2.1 n-pentanol.
2.2 Hydrochloric acid (1+1), extra pure. Store in a plastic bottle. 2.3 Sodium hydroxide solution (5%), extra pure. Add to a plastic bottle. 2.4 Glyoxal bis(2-hydroxyaniline) methanol solution (0.3%). Prepare when needed. 2.5 Double distilled water (this water is used in this method). 2.6 Calcium standard solution
2.6.1 Weigh 0.1399g of calcium oxide (99.90% or more) pre-burned at 900℃, place in a 250ml plastic cup, add 10ml hydrochloric acid (2.2), heat to dissolve in a water bath, cool, transfer to a 1000ml volumetric flask, dilute to scale with water, and mix. This solution contains 100ug calcium per ml. Store in a plastic bottle for later use. 2.6.2 Transfer 10.00ml of calcium standard solution (2.6.1), place in a 100ml volumetric flask, dilute to scale with water, and mix. This solution contains 10μg calcium per ml. Store in a plastic bottle for later use. Instrument
3.1 Chlorination device, as shown in the figure.
National Bureau of Standards 1984-04-12 issued
1985-08-01 implementation
GL4324.13-84
(-group vehicle (including the cost): 2-hydrogen chloride generator (containing sulfuric acid), 3-acid washing volume-6 annual flow: 6-mass impulse, 6-acid washing light! 7-gas distributor, 8-right English 2m0mm) support, 9-chemical protection, 10-thermocouple, Sichuan furnace temperature controller
41 hope to report the whole study and 20 taels,
4.2 Ya barrel weighing 0.1003-1.000 extended pigeon acid chain is first placed at the stone pipe mouth of the chlorination furnace for decomposition, and then pushed into the 600℃ high temperature zone to burn into three-calculation chemical diamond group certificate 54 determination
, confirm the section 0.11.c00 tungsten acid generation! We decompose the tube, and then push it into the 750℃ high temperature zone to burn into Wuhuahexie
420 powder content, and then the tube is oxidized into 5.4 net oxidized. The analysis should be released from the policy, and the measured value is within the allowable error in the room, and the long average value is taken. The sample (5, 2) is placed in the quartz tube high temperature zone of the nitriding furnace preheated to 750℃, and the chlorinated gas is passed through, and the flow rate is 9~150m/mn (the flow rate of the sharp current meter is divided into oxygen flow cushion floor) After the chemical reaction is completed, the platinum and bell are finally obtained.
5.3.2 Mix 6 ml of carboxylic acid (2.2) and 20 drops of water (1 ml), heat under an infrared lamp to dissolve, transfer half of the liquid into 60 ml of hot water, cool to room temperature (more than 32 minutes). Add 3.5 ml of sodium hydride solution (2.3), mix. 5.4.3 Dilute with water to 15 ml, mix well, add 1.5 ml of ethylenediamine bis (2-hydroxyaniline) methanol solution (2.4), mix well, immediately add 10 ml of orthopentyl alcohol (2.1), and add (2 minutes). After the extraction is completed, the organic phase should not be exposed to air), let it stand for 2 minutes, remove the aqueous phase, add 5 ml of n-pentanol (2.1, 2 minutes).
.4 Transfer the tidal fraction to the colorimetric method, and compare it with n-pentanol as a reference. , measure its absorbance at a wavelength of 540 nm with a spectrophotometer. (The measurement should be completed within 10 to 5 minutes). 5.4.5: Subtract the absorbance spot of the empty mountain made with the sample, and find out the corresponding calcium content from the 1 working line soil 40
GB4324.13-84
5.5 Drawing of working curve
Pipette 0.00, 0.50, 1., 1.50, 2.0), 2.50, 3.00ml of Levitra solution (2.6.2), respectively, into a 60ml distillation funnel pre-added with about 2ml of water, 12.5ml of sodium hydroxide solution (2.3), and measure its modified light intensity according to 4.3-5.4.1, subtract the absorbance produced by the additive, take the calcium standard, and use the absorbance as the vertical axis to make the curve. 6 Calculation of analysis results
The sieve content obtained by the above formula is
the calcium content obtained from the standard curve, g
7The difference between the analysis results of laboratories is as follows:
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Additional remarks:
This standard was proposed by the People's Republic of China and the Ministry of Metallurgy. This standard was drafted by Zhuzhou Cemented Carbide Co., Ltd. This standard was drafted by Zhuzhou Cemented Carbide Co., Ltd. In the standard drafted by the main drafter Jing Ya
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