This standard specifies the method for determining the fluorine content in copper concentrate. This standard is applicable to the determination of fluorine content in copper concentrate. GB/T 3884.5-2000 Chemical analysis method for copper concentrate Determination of fluorine content GB/T3884.5-2000 Standard download decompression password: www.bzxz.net

GB/T3884.5—2000
This standard is a reconfirmation of GB/T3884.6—1983 "Chemical analysis method for copper concentrates". This standard complies with:
Determination of fluorine content by ion selective electrode method" GB/T1.1-1993 Standardization work guidelines Unit 1: Rules for drafting and expressing standards Part 1: Basic provisions for standard writing GB/T1.4—1988 Standardization work guidelines Rules for the preparation of chemical analysis methods GB/T1467—1978 General principles and general provisions for chemical analysis methods for metallurgical products GB/T17433-1998 Basic terminology for chemical analysis of metallurgical products This standard replaces GB/T3884.6--1983 from the date of implementation. This standard is proposed by the State Bureau of Nonferrous Metals Industry. This standard is under the jurisdiction of the China Nonferrous Metals Industry Standard Metrology and Quality Research Institute. This standard was drafted by Daye Nonferrous Metals Company. The main drafting unit of this standard: Jiangxi Copper Company. The main drafters of this standard: Li Xianwei, Zhong Cuilan, Peng Li.
1 Scope
National Standard of the People's Republic of China
Chemical analysis method of copper concentrate
Determination of fluorine content
Methodsfor chemical analysis of copper concentrates-Determination of fluorine content This standard specifies the determination method of fluorine content in copper concentrate. This standard is applicable to the determination of fluorine content in copper concentrate. Determination range: 0.010%0.50%. 2 Principle of the method
GB/T3884.5-200Q
Replaces GB/T3884.6—1983
The sample is melted and decomposed with sodium hydroxide, and the melt is leached with water and filtered to separate fluorine from iron, copper, lead, etc. Then, in a sodium citrate-triethanolamine medium with a pH of 6.5-7.0, a saturated calomel electrode is used as the reference electrode and a fluoride ion selective electrode is used as the indicator electrode, and fluorine is measured using an electrode potentiometer.
In the measuring solution, 10 mg of aluminum trifluoride does not interfere with the determination. 3 Reagents
3.1 Sodium hydroxide, high-grade purity.
3.2 Sodium citrate (Na, C, H, O, ·2H, O) solution (294 g/L). 3.3 Nitric acid (1+4).
3.4 ​​Triethanolamine LN (CH,CH,0OH),] solution: 100mL triethanolamine plus 64mL hydrochloric acid (pl.19g/mL) to adjust to pH 6.5~7.0, dilute with water to 500mL, mix well. 3.5 Fluorine standard stock solution: Weigh 2.2110g sodium fluoride (superior purity) dried at 120℃ for 2h, dissolve in water, transfer to a 500mL volumetric flask, dilute to scale with water, mix well. Transfer to a dry plastic bottle for storage. This solution contains 2mg fluorine per mL. 3.6 Fluorine standard solution: Transfer 25.00mL fluorine standard stock solution (3.5) to a 500mL volumetric flask, dilute to scale with water, mix well. Transfer to a dry plastic bottle. This solution contains 100μg fluorine per mL. 3.7 Fluorine standard solution: Pipette 50.00mL of fluorine standard solution (3.6) into a 500mL volumetric flask, dilute to scale with water, and mix. Immediately transfer to a dry plastic bottle. This solution contains 10μg fluorine in 1mL. 3.8 Phenol red solution (2g/L): Weigh 0.1g phenol red, add 6mL sodium hydroxide solution (0.05mol/L), dilute to 50mL with water, and mix.
4 Instruments
4.1 Bottle ion selective electrode: The fluorine content is required to be within the concentration range of 10-1~10-mol/L, and the electrode potential and the negative logarithm of the concentration show a good linear relationship. Before use, the electrode should be soaked in 10-3mol/L sodium fluoride solution for 1h to activate it, and then washed with water until the washing liquid contains no more than 10-\mol/L fluorine before measurement. 4.2 Saturated calomel electrode.
Approved by the State Administration of Quality Supervision, Inspection and Quarantine on February 16, 2000, 28
Implemented on August 1, 2000
4.3 Potentiometer: accuracy 0.1mV.
4.4 Electromagnetic stirrer.
5 Sample,
5.1 The sample particle size should not be greater than 0.082mm. GB/T3884.5--2000
5.2 The sample should be dried in an oven at 100105°C for 1h and placed in a desiccator to cool to room temperature. 6 Analysis steps
6.1 Sample
Weigh 0.50g of sample to an accuracy of 0.0001g. Perform two independent measurements and take the average value. 6.2 Blank test
Perform the procedures in 6.3.1 to 6.3.3 in 30mL nickel without the sample. This solution is used for 6.4. 6.3 Determination
6.3.1 Place the sample (6.1) in a 30mL nickel crucible, add 6g of sodium hydroxide, heat and melt in a small electric furnace surrounded by an asbestos ring to dehydrate, and mix. Place in a high-temperature furnace heated to 600℃ to melt for 10 minutes, take out, shake the melt evenly on the crucible wall, and cool slightly. 6.3.2 Place the crucible and the melt in a 250mL beaker pre-filled with 50mL of hot water, cover with a watch glass, heat and soak the melt, and wash the watch glass, ground cover and glass rod with water.
6.3.3 Dilute the solution to about 80mL with water, heat and boil for 1min, transfer the solution and the precipitate into a 100mL volumetric flask after cooling, dilute to the mark with water, mix, and dry filter. 6.3.4 Transfer 10.00mL of the filtrate into a 50mL volumetric flask, add 15mL of sodium citrate solution and 1 drop of phenol red solution (3.6), and adjust with nitric acid until the solution just turns yellow.
6.3.5 Add 5mL of triethanolamine solution, dilute to the mark with water, and mix. 6.3.6 Pour all the solution into a dry 100mL beaker, put in a stirring rod, insert a fluoride ion selective electrode and a saturated calomel electrode, and measure the equilibrium potential value on a potentiometer under electromagnetic stirring. Note: The equilibrium potential refers to the electrode potential change of no more than 0.2mV per minute under stirring. 6.4 Drawing of working curve
Pipette 0.50, 1.00, 2.50, 5.00mL of fluorine standard solution (3.7) and 1.00, 1.50, 2.50mL of fluorine standard solution (3.6), respectively, and place them in a group of 50mL volumetric flasks, add 10mL of sample blank solution (6.2), 15mL of sodium citrate solution, 1 drop of phenol red solution, and adjust with nitric acid until the solution just turns yellow. The following operations are carried out according to 6.3.5 and 6.3.6, and the fluorine concentration is measured simultaneously with the sample in the order from low to high. On the semi-logarithmic coordinate paper, draw the working curve with the fluorine ion concentration value as the horizontal axis and the potential value as the vertical axis. 7 Expression of analysis results
Calculate the fluorine percentage according to formula (1):
F(%) = CV. .V,X 10-6
Wherein: c is the fluorine concentration obtained from the working curve, μg/mL; V. is the total volume of the test solution, mL;
V. is the volume of the test solution taken, mL
V is the volume of the test solution to be measured, mL
is the mass of the sample, 8.
The result is expressed to two decimal places. If the fluorine content is less than 0.10%, it is expressed to three decimal places. ·(1)
3 Allowable difference
GB/T3884.5-2000
The difference between the analysis results of laboratories should not be greater than the allowable difference listed in Table 1: Table 1
>0.050~0.10bzxz.net
>0.10~0.30
>0.30~0.50
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