YS/T 252.3-2007 English PDF (YST252.3-2007)

This Part specifies the method for determination of cobalt content in high nickel matte. This Part is applicable to the determination of cobalt content in high-nickel matte. Measuring range: 0.1% ~ 2%. 2 Method summary Decompose the sample with hydrochloric acid, nitric acid-potassium chlorate saturated solution. Use air-acetylene flame in hydrochloric acid (2 + 98) medium, to measure the absorbance at the wavelength of 240.7 nm of atomic absorption spectrometer, after subtracting the background. Calculate the cobalt content according to the standard curve method. 3 Reagents 3.1 Hydrochloric acid (¦Ñ1.19 g/mL). 3.2 Nitric acid (¦Ñ1.42 g/mL). 3.3 Nitric acid (1 + 1). 3.4 Ammonia (1 + 3). 3.5 Nitric acid-potassium chlorate saturated solution: Dissolve potassium chlorate in nitric acid (3.2) until saturated. 3.6 Cobalt standard storage solution: Weigh 1.0000 g of metallic cobalt (mass fraction of cobalt ¡Ý 99.95%). Slowly add 20 mL of nitric acid (3.3) into a 400 mL beaker. Cover with a watch glass. Heat at low temperature to completely dissolve. Remove it. Use water to rinse the watch glass and cup wall. Heat and boil to remove nitrogen oxides. Remove it. Cool to room temperature. Transfer it into a 1000 mL volumetric flask. Use water to wash the watch glass and cup wall. Combine the washing liquid into the volumetric flask. Use water to make the volume reach to the mark. 1 mL of this solution YS/T 252.3-2007 www.ChineseStandard.net ? Buy True-PDF ? Auto-delivery. Page 6 of 8 contains 1 mg of cobalt. 3.7 Cobalt standard solution: Pipette 20.00 mL of cobalt stand