YS/T 252.3-2007 in English

Methods for chemical analysis of nickel matte - Determination of cobalt content - Flame atomic absorption spectrometric method

1 Scope

This part specifies a method for determining the cobalt content in nickel matte.

This part is applicable to the determination of cobalt content in nickel matte, with a determination range of 0.1%-2%.

2 Principle

The test portion is decomposed with hydrochloric acid and nitric acid-potassium chlorate saturated solution. In the hydrochloric acid (2+98) medium, the air-acetylene flame is used to measure the absorbance of the solution at the wavelength of 240.7 nm of the atomic absorption spectrometer with the background deducted. The cobalt content is calculated with the standard curve method.

3 Reagents

3.1 Hydrochloric acid ( 1.19g/mL).

3.2 Nitric acid ( 1.42 g/mL).

3.3 Nitric acid (1+1).

3.4 Aqueous ammonia (1+3).

3.5 Nitric acid-potassium chlorate saturated solution: Dissolve potassium chlorate in nitric acid (3.2) until saturation.

3.6 Cobalt standard stock solution: Weigh 1.000 0 g of metallic cobalt (mass fraction of cobalt ≥ 99.95%), slowly add 20 mL of nitric acid (3.3) into a 400-mL beaker, cover the beaker with watch glass, heat the beaker at low temperature to completely dissolve the metallic cobalt; remove the watch glass, flush the watch glass and the beaker wall with water, heat to boil to remove nitrogen oxides, then remove the beaker. Cool the solution to room temperature, transfer it into a 1,000-mL volumetric flask, flush the watch glass and the beaker wall with water, pour the flushing liquid into the volumetric flask, and dilute the solution to the scale with water. The cobalt content of the solution is 1 mg/mL.

3.7 Cobalt standard solution: Pipette 20.00 mL of cobalt standard stock solution (3.6) into a 200-mL volumetric flask, and dilute it to the scale with water. The cobalt content of the solution is 100 μg/mL.

4 Apparatus

Atomic absorption spectrometer (with a background deduction function), equipped with cobalt hollow cathode lamp.

Foreword i
1 Scope
2 Principle
3 Reagents
4 Apparatus
5 Analytical procedures
6 Calculation and expression of analysis results
7 Precision
8 Quality assurance and control