GB/T 5120.1-1995 Chemical analysis methods for crude copper - Determination of copper content

GB/T 5120.1-1995 Chemical analysis method for crude copper Determination of copper content GB/T5120.1-1995 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Determination of copper content
Chemical analysis methods of blister copper
Methods for chemical analysis of blister copperDetermination of copper content1 Subject content and scope of application
This standard specifies the method for determining the copper content in blister copper. This standard is applicable to the determination of the copper content in blister copper. Determination range: 97.50%~99.70%. 2 Reference standards
GB1.4 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 3 Summary of methods
GB/T5120.1---1995
Replaces GB5120.185
The sample is dissolved in nitric acid, trivalent arsenic and antimony are oxidized with bromine, the pH value of the solution is controlled to be 3~4, and iron is masked with ammonium bifluoride. Add potassium iodide to react with copper valence. The precipitated iodine is titrated with sodium thiosulfate standard titration solution using starch as an indicator. 4 Reagents
4.1 Potassium iodide.
4.2 Saturated ammonium hydrogen fluoride solution: Store in a butyl polyethylene bottle. 4.3 Ammonia water (p0.90 g/mL).
4.4 Glacial acetic acid (pl.05 g/mL).
4.5 Nitric acid (1+2).
4.6 Saturated bromine solution.
4.7 Potassium thiocyanate solution (200g/L). Www.bzxZ.net
4.8 Starch solution (5g/1.).
4.9 Standard sodium thiosulfate titration solution c(Na.S,O,·5H,O)=0.1mol/1]. 4.9.1 Preparation: Weigh 250g sodium thiosulfate (Na2S.0:·5H2O) and dissolve it in a 1000ml beaker. Add 2g anhydrous sodium carbonate, transfer to a 101 brown reagent bottle, dilute to about 101 with boiled and cooled distilled water, add 1ml difluoromethane, shake well, and let stand for two weeks. Filter when using, add 1mL chloroform, mix well, and let stand for 2h. 4.9.2 Calibration: Weigh 3g (accurate to 0.0001g) of treated copper sheet (≥99.95%) in triplicate. The following is carried out in accordance with 6.2.1 to 6.2.4 and the determination of the test sample at the same time.
Note: Treatment of copper sheet. Put the copper sheet into slightly boiling glacial acetic acid (1+4) and slightly boil for 1min. After taking it out, wash it twice with water and anhydrous alcohol respectively. Bake in a 100°C oven for 4 minutes, cool, and place in a ground-mouth reagent bottle for later use. Calculate the actual concentration of the sodium thiosulfate standard titration solution according to formula (1): Approved by the State Administration of Technical Supervision on October 17, 1995 174
Implemented on March 1, 1996
GB/T5120.1-1995
V.X0.06355
Wherein: c-actual concentration of sodium thiosulfate standard titration solution, mol/L; W copper content of electrolytic copper sheet, %; r electrolytic copper solution fractionation ratio;
V,-the volume of sodium thiosulfate standard titration solution consumed by electrolytic copper solution during titration, mI.; 0.063 55-
With 1.00ml. sodium thiosulfate standard titration solution Lc (Na2S.O: ·5H0)==1.00mol/1. mass·g parallel calibration three times the relative error of the measured value is not greater than 0.2%, take the average value, otherwise recalibrate. 5 Instruments
Burette (50ml), see the figure below
Schematic diagram of burette
6 Analysis steps
6.1 Sample
According to the mass ratio after screening, 3g sample is called, accurate to 0.0001g. Two independent determinations are carried out and the average value is taken. 6.2 Determination
6.2.1 Place the sample (6.1) in a 500mL conical beaker, slowly add 50ml. nitric acid, cover with Table III, and after the violent reaction stops, heat it at a low temperature on a hot plate to completely dissolve it. Remove, wash Table III and the cup wall with water, and cool to room temperature. 175
GB/T 5120.1—1995
6.2.2 Transfer the solution into a 500mL volumetric flask (if there is residue, filter it), wash the beaker with water, add the washing liquid into the container, and dilute to the mark with water. Transfer 50mL of the test solution into a 500mL conical beaker. 6.2.3 Add 2ml of bromine saturated solution and place it on a hot plate at low temperature to evaporate the solution until the volume is about 1ml. Remove, blow and wash the cup wall with 30mL of slightly cold water, and mix well. Cool to room temperature.
6.2.4 Neutralize with nitrogen water until copper hydroxide precipitates, add 3mL of glacial acetic acid and 1mL of saturated ammonium bifluoride solution, rinse the cup wall with water, and mix well. Add about 4g of potassium iodide, and titrate with sodium thiosulfate standard titration solution. When the solution is light yellow, add 5ml starch solution and continue to titrate until the solution is light blue. Add 5mL potassium thiocyanate solution, shake, and after the adsorbed iodine is released, continue to titrate until the light vegetable color disappears, which is the end point.
7 Expression of analysis results
Calculate the percentage of copper according to formula (2):
Cu(%) = :V:×0. 063 55 × 100mo+r
Where: - the actual concentration of sodium thiosulfate standard titration solution, mol/L; V---the volume of sodium thiosulfate standard titration solution consumed by the titration sample solution during the determination, mL; test solution fraction ratio;
the mass of the sample, g;
the mass equivalent to 1.00mL sodium thiosulfate standard titration solution Lc (Na2S:O:·5H,0)=1.00mol/L+g. 0.063 55--
The result is expressed to two decimal places.
8Permissible difference
The difference between the analysis results of laboratories should not be greater than the permissible difference listed in the following table. Road
97.50~~98.50
98.50~99.00
99.00~99.70
Additional remarks:
This standard was proposed by China Nonferrous Metals Industry Corporation. This standard was revised by Daye Nonferrous Metals Corporation. This standard was revised by Dazhi Nonferrous Metals Corporation. The main editors of this standard are Wang Li and Wang Yongbin. 176
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