Analytical methods for cadmium, silver and indium in high purity aluminum

Appendix A

Analytical methods for cadmium, silver and indium in high purity aluminum

Measurement range: cadmium content: 1X10-5%~2.5X10-4%; helium content 2X10-5%~5X10-4%; silver content 1%~8X10-5%.

This standard complies with GBT 1647-1978 "Standards and General Rules for the Standards of Chemical Analysis of Metallurgical Products"

A1.1 Determination of cadmium content

Al.1 Method Summary

The sample was dissolved in hydrochloric acid and nitric acid. In the presence of potassium cyanide-tartaric acid, it was extracted with a dithizone-trichloromethane solution and then extracted with dithizone-carbon tetrachloride and subjected to photometric determination at a wavelength of 518 nm.

A1.2 Reagents

Al.2.1 Hydrochloric acid (ρl.19g/mL) (GR),

Al.2.2 Nitric acid (ρl.42g/mL) (GR),

A1.2.3 Potassium sodium tartrate solution (50%). After preparation, it should be slightly alkaline, filtered and extracted with dithizone-trichloromethane solution until the organic phase is green and stored in quartz vessels.

Al.2.4 Sodium hydroxide solution (40%) (GR).

Al.2.5 Potassium cyanide solution (10%),

A1.2.B dithizone-trichloromethane (0.01%).

Al.2.7 tartaric acid solution (2%) (GR).

Al.2.8 Trichloromethane.

Al.2.9 Light amine hydrochloride solution (25%) (GR),

A1.2.10 Dithizone-carbon tetrachloride solution (0.01%), diluted with carbon tetrachloride to 0.002% when used, stored in dark place and used within 2 days.

A1.2.11 Standard cadmium stock solution, 1 mL containing 0.1 mg cadmium.

A1.2.12 cadmium standard solution, 1mL containing 0.1Kg of cadmium.

A1.3 Instruments

Spectrophotometer.

A1.4 Analysis Procedure

A1.4.1 Determination quantity: In the analysis, 2 samples shall be weighed and measured, and the average value shall be taken.

Al.4.2 Sample: Weigh 2.000g sample.

Al.4.3 blank test: blank test along with the sample.

Al.4.4 Determination

Al.4.4.1 Place the sample (Al.4.2) in a 100 mL quartz cup. Add 20mL of water, 30mL of hydrochloric acid (Al.2.1), 10ml of nitric acid (Al.2.2), hold 50ml on the sand bath after the violent reaction is stopped, and gently heat until the sample is completely dissolved and evaporate to precipitate. Crystallization (blank distilled to 25-28 mL). Add a small amount of water and heat to dissolve the salt, remove it, and transfer it to a polyethylene cup. Add 30mL potassium sodium tartrate (Al.2.3), mix, add 30ml with polyethylene cup, sodium hydroxide (Al.2.4), mix, add 2mL of potassium cyanide (Al.2.5), and mix. Stir with a plastic rod, until the precipitate is completely dissolved, so that the volume does not exceed 100 ml, and cool to room temperature.

Al.4.4.2 The test solution was transferred to 250 mL. In a separatory funnel, 25 ml of dithizone-trichloromethane (Al.2-6) was added and extracted for 2 min. The organic phase was transferred to another separatory funnel containing 25 ml of tartaric acid (Al.2.7), and 10 mL of trichloromethane (Al.2.8) was added to the aqueous phase and shaken for 0.5 min. Combine the organic phases (be careful not to mix the lye into the organic phase). The organic phase was stirred vigorously with tartaric acid for 5 min and the organic phase was discarded. The aqueous phase was washed by shaking with 5 mL of chloroform (Al. 2.8) and the organic phase was discarded. Add 0.5 ml of hydrochloric acid via amine (Al.2.9), 3 ml of sodium hydroxide (Al.2.4), and mix. Add 10.0 mL of dithizone-carbon tetrachloride solution (Al.2.10) to extract for 1 min and discard the aqueous phase.

Al.4.4.3 The organic phase was placed in a 2 cm cuvette. Using water as a reference, absorbance was measured at a wavelength of 518 nm at the spectrophotometer.

Al.4.4.4 After subtracting the blank absorbance from the absorbance obtained, check the corresponding curve from the standard curve. ..

Al.4.5 Standard Curve Drawing

Al, 4, 5.1 Pipette 0, 0.50, 1.00, 2.00, 3.00, 4.00, 5.00 μg of cadmium standard solution (A1.2.12) in a set of polyethylene cups, respectively. Dilute to 50 mL with water, add 30 mL of sodium potassium tartrate (Al.2.3), 10 mL of sodium hydroxide (Al.2.4), 2 mL of potassium cyanide (Al.2.5), and mix. Cool to room temperature.

Al.4.5.2 Operate according to Al.4.4.2 and Al.4.4.3.

Al.4.5.3 Draw a standard curve by taking cadmium as the abscissa and the corresponding absorbance minus the blank as the ordinate.

A1.5 Calculation of Analysis Results

Calculate the percentage of tin according to formula (Al): Cd(%)=(m1/m0) X100 ..........................( Al)

In the formula:

M1—the amount of cadmium detected from the standard curve, g;

m0—Amount of sample, g.

A1.6 Allowable difference

The difference between the results of the analysis between laboratories should not be greater than the allowable difference listed in Table A1.

Table Al %

The tolerance of cadmium is 0.00001~0.0001 0.00004 >0.0001~0.00025 0.00005

A2 Determination of helium content

A2.1 Method Summary

The sample was dissolved in hydrochloric acid and nitric acid. The indium and bromide acid were reacted to form indium arsenide complex, extracted with butyl acetate, and then stripped with hydrochloric acid to develop indium and crystal violet, and then extracted with benzene for photometric determination.

A2.2 Reagents

A2.2.1 Hydrochloric acid (p1.19g/mL) (1+1)(GR).

A2.2.2 Nitric acid (p1.42g/mL).

A2-2-3 Bromohydride (5mol/L).

A2.2-4 Butyl acetate.

A2.2-5 Bromohydride (5mol/L).

A2.2-6 Hydrogen peroxide (30%)

A2.2.7 Sulfuric acid (2.5mol/L),

A2-2-8 ascorbic acid (l%).

A2.2.9 Potassium iodide (4mol/L),

A2.2.10 Sodium thiosulfate (0.1mol/L),

A2.2.11 Crystal Violet (0.1%)

A2.2.12 Benzene.

A2.2-13 Indium standard stock solution, 1 mL containing 1 mg indium.

A2.2-14 indium standard solution, 1mL containing 0.01mg of indium.

A2.3 Instruments

Spectrophotometer.

A2.4 Analysis Procedure

A2.41 Determination quantity: In the analysis, 2 samples shall be weighed for measurement and averaged.

A2.4.3 Blank test: Blank test with the sample.

A2.4.4 Determination

A2.4.4.1 Place the sample (A2.4.2) in a quartz cup. Add 10 mL of water, 30 mL of hydrochloric acid (A2.2.1), and 10 mL of nitric acid (A2.2.2). After the solution is dissolved, heat and dry it at low temperature (does not precipitate oxides). Add 20 mL of hydrobromic acid (A2.2-3), evaporate to dryness at a low temperature, and add 20 mL of hydrobromic acid, as described above until no more bromine is generated when bromide is added.

A2.4.4.2 Add 10 mL of water to the cup and dissolve the salts with 40 mL of bromide (A2.2.3) and transfer to the human separation funnel. Add 25m1 of butyl acetate (A2.2.4), extract for 2min, extract twice, and combine the organic phases. The organic phase was washed by shaking with 10 mL of hydrobromic acid (A2.2.5) and the aqueous phase was discarded.

A2.4.4.3 Add 2 drops of hydrogen peroxide (A2.2.6) to the organic phase, back-extract 20 mL of hydrochloric acid (1+1), and repeatedly strip twice, and combine the aqueous phases in a 50 mL quartz cuvette. Heat to dryness by evaporation, add 2 mL of sulfuric acid (A2.2.7) to dissolve the salts, and wash the test solution into a 50-mL sepatory funnel with 2 mL of sulfuric acid (A2.2.7) and 2 mL of water.

A2.4.4.4 Add 0.5 mL of ascorbic acid (A2.2.8), 2 mL of potassium iodide (A2.2.9), 0.2 mL of sodium thiosulfate (A2.2.10), 2 mL of crystal violet (A2.2.11), and 10.0 mL of benzene (A2. 2.12) Extract for 1 min and discard the aqueous phase. Place 30min

A2.4.4.5 Place part of the organic phase in a dry 2 cm cuvette. Using benzene as a reference, measure the absorbance at a wavelength of 610 nm at the spectrophotometer.

A2.4.4.6 After subtracting the blank absorbance from the measured absorbance, check the corresponding indium amount from the standard curve.

A2.4.5 Drawing a Standard Curve

A2.4.5.1 Pipette 0, 0.5, 1.0, 2.0, 3.0, 4.0, 6.0, 8.0, 10.0 μg of indium standard solution (A2.2.14) into a 50 ml separatory funnel, respectively, and add 4 mL of sulfuric acid (A2). .2.7), 2mL water.

A2.4-5.2 operates in accordance with A2.4.4.4 and A2.4.4.5.

A2.4.5.3 Draw the standard curve with the amount of indium as the abscissa and the corresponding absorbance of the blank minus the ordinate.

A2.5 Calculation of Analysis Results

Calculate the percentage of lanthanum by formula (A2)..

In(%)=(m1/m0)X 100.......................(A2)

In the formula:

M1—the amount of gadolinium detected from the standard curve, g;

m0—Amount of sample, g.

A2.6 Allowable difference

The difference between the results of the analysis between laboratories should not be greater than the allowable difference listed in Table A2.

Table: A2

Indium Allowance Difference 0.00002~0.0002 0.00004 >0.0002~0.0005 0.00006

A3 Determination of silver content

A3.1 Method Summary

The sample was dissolved in hydrochloric acid and nitric acid. In the pH 1~3 solution, silver was extracted and enriched with dithizone-carbon tetrachloride. Determination of Silver by the Catalytic Effect of Silver on Manganese Persulfuric Acid Reaction System in Acidic Medium.

A3.2 Reagents

A3.2.1 Hydrochloric acid (ρ 1.19 g/mL) (GR),

A3.2.2 Nitric acid (ρ1.42g/mL) (GR),

A3.2.3 Ascorbic Acid (5%) (GR),

A3.2.4 Dithizone-carbon tetrachloride solution (0.005%)

A3.2.5 Sulfuric acid (1+1)(GR)

A3.2.6 Perchloric acid (70%) (GR),

A3.2.7 Phosphoric acid (1+1),

A3.2.8 Manganese Sulfate (0.006mol/L),

A3.2.9 Potassium persulfate.

A3.2.10 Silver standard stock solution, 1 mL containing 0.10 mg silver.

A3.2.11 silver standard solution, 1mL containing 0.5μg silver.

A3.3 Instruments

Spectrophotometer.

A3.4 Analysis Procedure

A3.4.1 Measurement quantity: During the analysis, 2 samples shall be weighed and measured, and the average value shall be taken.

A3.4-2 Sample: Weigh 0.5000g sample.

A3.4.3 blank test: blank test along with the sample.

A3.4.4 Determination

A3.4.4.1 Place the sample (A3.4.2) in a 50 ml quartz cup, add 10 mL of hydrochloric acid (A3.2.1), and add 3-5 mL of nitric acid (A3.2.2). Wait until the reaction is intense and continue heating on a hot plate. To completely dissolved and evaporated to near dryness. Remove, quickly add 5mL of nitric acid (A3.2.2), continue to heat and slowly swing the salt attached to the cup moist, evaporated to a glass, add 5mL of nitric acid (A3.2.2) continue to evaporate to the glass ( Slightly dry it anyway). Add 40mL of water and heat to completely dissolve the salts. Add 1mL of ascorbic acid (A3.2-3) after cooling (if iron content is minimal). Use a test paper to check the pH should be 1~3, otherwise use dilute nitric acid and Ammonium hydroxide regulation.

A3.4.4.2 Transfer the test solution into a separatory funnel, rinse the quartz cup with a small amount of water, and combine the washing solution into a separatory funnel. Add 5 mL of dithizone-carbon tetrachloride (A3.2.4) and extract for 2-3 min. The organic phase was separated into another separating funnel. The extraction is repeated once more. The organic phases are combined. The organic phase was extracted once with 5 mL of water. The organic phase was carefully filtered into the original beaker and evaporated to dryness at low temperature.

A3.4.4.3 Add 0.5 mL of sulfuric acid (A3.2.5), 0.25 mL of perchloric acid (A3.2.6), evaporate to white smoke, cool, add 0.5 mL of nitric acid (A3.2.2), and evaporate to near dryness. Remove the cup wall with 2-3 mL of water, add 2 mL of phosphoric acid (A3.2.7), and heat for 2-3 minutes to fully dissolve the residue. After dissolving it, remove it, scrub the cup wall with a little water and a wiper, and wash it into a 25 mL colorimetric tube.

A3.4.4.4 Add 1 mL of manganese sulfate (A3.2.8), 0.5 g of potassium peroxyate (A3.2.9), dilute to 10 mL, and mix. Put in boiling water for 7min, rapidly cool to room temperature with running water, accurately dilute to 10mL, and mix.

A3.4.4.5 Place part of the solution in an Icm cuvette. Using water as a reference, measure the absorbance at a wavelength of 530 nm at the spectrophotometer.

A3.4.4.6 After subtracting the blank absorbance from the measured absorbance, check the corresponding silver amount from the standard curve.

A3.4.5 Drawing a Standard Curve

A3.4.5.1 Pipette 0, 0.05, 0.10, 0.20, 0.30, 0.40 μg silver standard solution (A3.2.11) into a set of quartz cups, respectively. Add 40mL of water each, 2-3 drops of nitric acid (A3.2.2) so that the pH is between 1-3.

A3.4.5.2 Operate according to A3.4.4.2~A3.4.4.5.

A3.4.5.3 Use silver as the abscissa, subtract the absorbance after the blank as the ordinate, and draw a standard curve.

A3.5 Calculation of Analysis Results

Calculate the percentage of silver according to formula (A3):

Ag(%)=(m1/m2)X100...............(A3)

In the formula:

M1—the amount of silver detected from the standard curve, g.

m2—Amount of sample, g.

A3.6 Allowable difference

The difference between the results of the analysis between laboratories should not be greater than the allowable difference listed in Table A3.

Table: A3 %

The amount of silver allowed to be poor 1~8X10-5 2X10-5

Attachment: High purity aluminum quality standard YS/T275-2000 (GB)

Note: This information was originally created by the Mine Secretariat . Please indicate the source.