GB/T 31194-2014High purity zinc sulfide for industrial use (English PDF)

5.1 General provisions

The reagents and water used in this Standard, when no other requirements are specified, refer to analytical reagents and grade-3 water specified in GB/T 6682-2008. The standard titration solutions, impurity standard solutions, preparations and products that are used in the test shall be prepared in accordance with the provisions of HG/T 3696.1,

HG/T 3696.2, HG/T 3696.3 when no other requirements are specified.

Take the arithmetic mean of the parallel determination results as the determination result; the absolute difference between the two parallel determination results shall not be larger than 0.2%.

5.4.1 Method summary

After dissolving the sample, measure the absorbance of each element on a graphite furnace atomic absorption spectrophotometer, and calculate the content of each element using the working curve method.

5.4.2 Reagents

5.4.2.1 Nitric acid solution. 2+98

1 mL of solution contains 0.1 µg/mL each of iron (Fe), lead (Pb), copper (Cu), nickel (Ni), manganese (Mn) and cadmium (Cd). Pipette 1.00 mL of the standard solution of iron (Fe), lead (Pb), copper (Cu), nickel (Ni), manganese (Mn) and cadmium (Cd) prepared according to 5.4.2.4 into the 100 mL volumetric flasks; add 0.2 mL of nitric acid solution (see 5.4.2.2); use grade-1 water to dilute to the mark; shake well. This solution shall be prepared before use.

5.4.2.2 Nitric acid solution. 1+1, prepared using high-purity reagents

5.4.2.3 Hydrochloric acid solution. 1+1, prepared using high-purity reagents

5.4.2.4 Mixed standard solution of iron, lead, copper, nickel, manganese and cadmium.

1 mL of solution contains 0.01 mg/mL each of iron (Fe), lead (Pb), copper (Cu), nickel (Ni), manganese (Mn) and cadmium (Cd). Pipette 1.00 mL of the standard solution of iron (Fe), lead (Pb), copper (Cu), nickel (Ni), manganese (Mn) and cadmium (Cd) prepared according to HG/T 3696.2 into the 100 mL volumetric flasks respectively; add 0.2 mL of nitric acid solution (see 5.4.2.2); use grade-1 water to dilute to the mark; shake well. This solution shall be prepared before use.

5.4.2.5 Mixed standard solution of iron, lead, copper, nickel, manganese and cadmium.

5.4.2.6 Grade-1 water, in accordance with the requirements of GB/T 6682-2008

5.4.3 Instruments

Graphite furnace atomic absorption spectrophotometer. equipped with iron, lead, copper, nickel, manganese, and cadmium hollow cathode lamps.

5.4.4 Analysis steps

5.4.4.1 Cleaning of instruments

Before cleaning, all instruments shall be decontaminated, rinsed with water, soaked in nitric acid solution (see 5.4.2.1) for 24 hours, rinsed several times with grade-1 water, and dried to prevent dust contamination.

5.4.4.2 Preparation of test solution

Weigh approximately 0.1 g ~ 2 g of sample A (see 5.6.2) according to the content of impurity elements in the sample, accurate to 0.000 2 g; place it in a beaker; add 5 mL of hydrochloric acid solution; cover with a watch glass; heat at low temperature until almost dry; remove. Add water to dissolve the salts; cool and transfer all to a 50 mL (V) volumetric flask; use grade-1 water to dilute to the mark; shake well.

At the same time, perform a blank test. Except for not adding the sample, the types and amounts of other reagents added are exactly the same as those of the test solution and are treated in the same way as the sample.

5.4.4.3 Drawing of the working curve

Take four 50 mL volumetric flasks; add 0.00 mL, 5.00 mL, 10.00 mL, and 15.00 mL of the mixed standard solution (see 5.4.2.5), respectively; add 0.2 mL of nitric acid solution (see 5.4.2.2); use grade-1 water to dilute to the mark; shake well. This standard series solution I is used for the determination of lead and nickel content. The concentrations of lead (Pb) and nickel (Ni) are 0 µg/L, 10 µg/L, 20 µg/L, and 30 µg/L, respectively.

Take four 100 mL volumetric flasks; add 0.00 mL, 5.00 mL, 10.00 mL, and 15.00 mL of the mixed standard solution (see 5.4.2.5), respectively; add 0.2 mL of nitric acid solution (see 5.4.2.2); use grade-1 water to dilute to the mark; shake well. This standard series solution II is used for the determination of iron and copper contents. The concentrations of iron (Fe) and copper (Cu) are 0 µg/L, 5 µg/L, 10 µg/L, and 15 µg/L, respectively.

Take four 100 mL volumetric flasks; add 0.00 mL, 2.50 mL, 5.00 mL, and 10.00 mL of the mixed standard solution (see 5.4.2.5) respectively; add 0.2 mL of nitric acid solution (see 5.4.2.2); use grade-1 water to dilute to the mark; shake well. This standard series solution III is used for the determination of manganese content. The concentrations of manganese (Mn) are 0 µg/L, 2.5 µg/L, 5 µg/L, and 10 µg/L, respectively.

Take four 100 mL volumetric flasks; add 0.00 mL, 0.50 mL, 1.00 mL, and 2.00 mL of the mixed standard solution (see 5.4.2.5) respectively; add 0.2 mL of nitric acid solution (see 5.4.2.2); use grade-1 water to dilute to the mark; shake well. This standard series solution IV is used for the determination of cadmium content. The concentrations of cadmium (Cd) are 0 µg/L, 0.5 µg/L, 1 µg/L, and 2 µg/L, respectively.

On a graphite furnace atomic absorption spectrophotometer, adjust the instrument to the optimal state at the determination wavelength of each impurity element given in Table 2; measure the absorbance of the element to be measured in each standard series Take the arithmetic mean of the parallel determination results as the determination result; the absolute difference between the two parallel determination results shall not be larger than 0.02%.

5.7 Determination of bulk density

5.7.1 Method summary

A certain amount of sample passes through a conical funnel and falls freely into a cylindrical material tank of known volume. Accurately weigh the mass of the sample filling the material tank, and obtain the bulk density of the sample by calculation.

5.7.2 Instruments and apparatuses

Same as the requirements in Chapter 3 of GB/T 23771-2009.

5.7.3 Analysis steps

Same as the requirements in Chapter 4 of GB/T 23771-2009.

5.7.4 Result calculation

Same as the requirements in Chapter 5 of GB/T 23771-2009.

Take the arithmetic mean of the parallel determination results as the determination result. The absolute difference between the two parallel determination results shall not be greater than 0.02 g/mL.

5.8 Determination of particle size

5.8.1 Instrument

Laser particle size analyzer. equipped with ultrasonic dispersion device.

5.8.2 Analysis steps

Weigh 1.0 g of sample; place it in a 100 mL beaker; add about 40 mL of water. Disperse in an ultrasonic disperser for 3 min ~ 5 min. Adjust the laser particle size analyzer to the optimal operating state of the instrument; measure the particle size (D50) of the sample according to the measurement steps specified by the laser particle size analyzer.