This standard specifies the determination method of copper content in tantalum and niobium. This standard is applicable to the determination of copper content in tantalum and niobium, and also to the determination of copper content in their hydroxides. Determination range: 0.0002~0.06%. GB/T 15076.3-1994 Chemical analysis method of tantalum and niobium Determination of copper content GB/T15076.3-1994 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Chemical analysis method of tantalum and niobium
Determination of copper content
Methods for chemical analysis of tantalum and niobium-Determination of copper content1 Subject content and applicable diagram
This standard specifies the method for determining the copper content in molybdenum and niobium. GB/T 15076.394bzxZ.net
This standard is applicable to the determination of copper content in molybdenum and niobium, and also to the determination of copper content in its hydroxide. Determination range: 0.0002%~0.06%.
2 Reference standards
GB 1.4 Guidelines for standardization work Provisions for the preparation of chemical analysis method standards GB1467 General principles and general provisions for chemical analysis method standards for metallurgical products GB7729 General principles for spectrophotometric methods for chemical analysis of metallurgical products 3 Principle of the method
The sample is dissolved with hydrofluoric acid and nitric acid. Tartaric acid-boric acid complex main body, with disodium ethylenediaminetetraacetic acid to eliminate the interference of impurities such as iron, nickel, cobalt, manganese, etc. At pH 7-8, copper (II) and sodium diethyldithiocarbamate form a brown-yellow complex, which is extracted with carbon tetrachloride and its absorbance is measured at a wavelength of 435nm by a photometer.
4 Reagents
4.1 Anhydrous sodium sulfate.
4.2 Hydrofluoric acid (p1.14g/mL), high-grade purity. 4.3 Nitric acid (pl.42g/mL), high-grade purity. 4.4 Ammonia water (p0.90g/ml.).
4.5 Carbon tetrachloride.
4.6 Tartaric acid-boric acid solution: Weigh 20g tartaric acid (high-grade purity) and 6g boric acid (high-grade purity) into a 250ml beaker, add water to dissolve and dilute to 100ml, mix.
4.7 Disodium ethylenediaminetetraacetic acid solution (50g/L). 4.8 Sodium diethyldithiocarbamate (copper reagent) solution (1g/L). 4.9 Copper standard stock solution: Weigh 0.1000g of metallic copper and place it in a 250mL beaker, add 20mL nitric acid (1+4). Heat at low temperature until completely dissolved, boil, remove nitrogen oxides, cool, transfer to a 1000mL volumetric flask, dilute to scale with water, and mix. This solution contains 100pg of copper in 1mL.
4.10 Copper standard solution: Transfer 10.00mL of copper standard stock solution (4.9) to a 100mL volumetric flask, dilute to scale with water, and mix. This solution contains 10μg of copper in 1mL.
Approved by the State Administration of Technical Supervision on May 9, 1994 490
Implemented on December 1, 1994
GB/T15076.3-94
4.11 Phenol red indicator: Weigh 0.1g phenol red, dissolve it in 6mL sodium hydroxide solution (0.5g/L), dilute to 100mL with water, and mix well.
5 Instruments
Spectrophotometer.
6 Analysis steps
6.1 Determination quantity
Weigh two samples, measure them independently, and take the average value. 6.2 Test material
Weigh the sample according to Table 1, accurate to 0.0001gTable 1
Copper content
0. 00020~0. 00100
0. 0010~ 0. 0035
0.0035~0.0080
0. 0080~~0. 0200
0. 020~~0. 040
0. 040~0.060
6.3 Blank test
Carry out a blank test together with the test material.
6.4 Determination
1,0000
Total volume of test solution
Volume of test solution
6.4.1 Place the test sample (6.2) in a 30ml platinum crucible, add a few drops of water to moisten it (add 1ml of water to the test sample), add 1-5ml of hydrofluoric acid (4.2), add nitric acid (4.3) dropwise, wait for the violent reaction to stop, and heat at low temperature until the test sample is completely dissolved. Continue to evaporate until a precipitate is precipitated, remove it, and add hydrofluoric acid (4.2) dropwise to just dissolve the precipitate. Add 10ml of tartaric acid-boric acid solution (4.6) to the crucible at once. If turbidity occurs, add hydrofluoric acid (4.2) dropwise until the solution is clear.
6.4.1.1 Transfer the test solution (6.4.1) to a 60ml separatory funnel according to Table 1. 6.4.1.2 Transfer the test solution (6.4.1) to the corresponding volumetric flask according to Table 1, dilute to the mark with tartaric acid-boric acid solution (4.6), and mix well. Divide the test solution into a 60mL separatory funnel.
6.4.2 Add 1mL of disodium ethylenediaminetetraacetic acid solution (4.7) and two drops of phenol red indicator (4.11) to the separatory funnel, and neutralize with ammonia water (4.4) until the test solution changes from yellow to red. Add 2mL of sodium diethyldithiocarbamate solution (4.8) and mix well. 6.4.3 Add 5.00mL of carbon tetrachloride (4.5) to the separatory funnel, shake for 1min, and let stand to separate the layers. 6.4.4 Place the organic phase into a 10mL dry colorimetric tube. Repeat the operation in 6.4.3 and combine the organic phase with the organic phase from the first extraction. Add about 0.5g of anhydrous sodium sulfate (4.1) to the colorimetric tube, shake several times, and let it stand for a while. 6.4.5 Transfer part of the organic phase to a 2cm dry absorption dish, and measure its absorbance at a wavelength of 435nm on a spectrophotometer with carbon tetrachloride (4.5) as a reference.
6.4.6 Subtract the absorbance of the blank solution accompanying the sample and find the corresponding copper base from the working curve. 6.5 Working curve drawing
6.5.1 Transfer 0.0.10, 0.30, 0.501.00, 1.50, 2.00mL of copper standard solution (4.10) and place them in a group of 60mL separatory funnels, respectively, and add 10mL of tartaric acid-boric acid solution (4.6). The following operations are carried out according to 6.4.2 to 6.4.5. 6.5.2 Subtract the absorbance of the reagent blank. Draw a working curve with the copper content as the horizontal axis and the absorbance as the vertical axis. 7 Calculation and expression of analysis results
Calculate the percentage of copper according to the following formula:
Cu(%)= m . V,X10-6
Where: ml—the amount of copper found from the working curve, μg, the volume of the test solution taken in one aliquot, mL,
the total volume of the test solution, mL,
8 Allowable difference
The mass of the sample, g.
The difference in analysis results between laboratories should not be greater than the allowable difference listed in Table 2. Table 2
Copper content
0. 00020~0. 00050
≥0. 00050~0. 00090
>0. 0009~0. 0025
>0. 0025 ~0. 0070
≥0. 0070~0. 0150
>0. 015~0. 040
>0.040~0.060
Additional remarks:
This standard was proposed by China Nonferrous Metals Industry Corporation. This standard was drafted by Ningxia Nonferrous Metals Smelter. This standard was drafted by Ningxia Nonferrous Metals Smelter. The main drafter of this standard is Song Yunjia.
Allowance difference
From the date of implementation of this standard, the former Ministry of Metallurgical Industry of the People's Republic of China issued the Ministry of Standard YB942 (11) - 78 "Determination of copper content in metallurgy (copper reagent absorptiometry)" will be invalid. :492
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.