HG/T 5919-2021Nickel sulfate for batteries (English PDF)

7.1 General

The reagents and water used in this document refer to analytically-pure reagents and grade three water specified in GB/T 6682-2008, unless otherwise specified. The standard titration solutions, impurity standard solutions, preparations and products used in the test shall be prepared according to the regulations of HG/T 3696.1, HG/T 3696.2 and HG/T 3696.3 unless otherwise specified.

7.3.1.3 Instruments and equipment

7.3.1.3.1 Glass sand crucible. filter plate pore size is 5 µm ~ 15 µm.

7.3.1.3.2 Electric constant temperature drying oven. the temperature can be controlled at 105°C ± 2°C.

7.3.1.5 Test data processing

The nickel content is calculated as the mass fraction w1 of nickel (Ni). Calculate according to formula (1).

7.3.2.2.1 Ammonium fluoride

7.3.2.2.2 Hydrochloric acid solution. 1+1

7.3.2.2.3 Ammonia solution. 1+1

7.3.2.2.4 Potassium sodium tartrate solution. 150 g/L

7.3.2.2.5 Sodium thiosulfate solution. 500 g/L

7.3.2.3.2 Test

Use a pipette to pipette 25 mL of the test solution. Place it in a 500 mL Erlenmeyer flask. Add 1 g ~ 2 g of ammonium fluoride, 10 mL of sodium potassium tartrate solution, 15 mL of sodium thiosulfate solution, 0.1 g of ammonium violate indicator. Shake well.

Add ammonia solution dropwise until the solution turns yellow. Use disodium EDTA standard titration solution to titrate till the solution turns orange yellow. Then add ammonia solution dropwise until the solution turns yellow. Continue to titrate with disodium edetate standard titration solution. After the solution becomes darker, add ammonia solution dropwise until the solution turns yellow. Use disodium edetate standard titration solution to titrate. Repeat this until the solution turns purple, which is the end point.

7.4.1 Principle

In nitric acid medium, use the standard curve method and inductively-coupled plasma optical emission spectrometer to determine the contents of the analyte elements.

7.4.2 Reagents or materials

7.4.2.1 Nitric acid solution. 1+1.

7.4.2.4 Water. grade two water specified in GB/T 6682-2008.

7.4.3 Instruments and equipment

Inductively-coupled plasma optical emission spectrometer.

7.4.4 Test steps

7.4.4.1 Drawing of standard curve

Pipette 0.00 mL, 0.50 mL, 1.00 mL, 2.00 mL, 4.00 mL, 8.00 mL of mixed standard solutions respectively. Place in six 100 mL volumetric flasks. Add 10 mL of nickel matrix solution and 2 mL of nitric acid solution respectively. Use water to dilute to the scale. Shake well.

7.5.4.2 Test

Weigh an appropriate amount of specimen (about 1.0 g for solid product, about 2.0 g for solution product) (accurate to 0.0002 g). Place in a 100 mL beaker. Add appropriate amount of water. Stir to dissolve all. Add 2 mL of nitric acid solution. Transfer all to a 100 mL volumetric flask. Add water to the scale. Shake well. Use a pipette to pipette 10 mL of the above test solution. Place in a 100 mL volumetric flask. Use water to dilute to the scale. Shake well.

7.6 Determination of water-insoluble content

7.6.1 Principle

The specimen is dissolved in water. After filtering and washing, dry it to constant mass.

Determine the water-insoluble content based on the amount of residue after drying.

7.6.2 Instruments and equipment

7.6.3 Analysis steps

Weigh about 50 g of specimen (accurate to 0.01 g). Place it in a 400 mL beaker. Add 200 mL of water. Heat and stir to dissolve. After cooling to room temperature, use a glass sand crucible that has been dried at 105°C ± 2°C to a constant mass for suction-filtration. After fully washing with hot water, place the glass sand crucible in an electric heating constant temperature drying oven at 105°C ± 2°C. Dry to constant mass.

7.7.5 Test data processing

The content of magnetic foreign matter is calculated as mass fraction w4.Calculate according to formula (6).

7.8 Determination of oil content

7.8.1 Reagents or materials

7.8.1.1 Tetrachlorethylene.

7.8.1.2 Anhydrous sodium sulfate.

7.8.2 Instruments and equipment

Infrared spectrophotometer.

8.3

Determine the number of sampling units according to the provisions of GB/T 6678. When sampling solid products, insert the sampler vertically from the center of the bag to 3/4 of the depth of the material layer for sampling.