UNI 2959-1949 Procedures for chemical analysis of metallic materials. Determination of cobalt content f steels. Weight method with zinc oxide and with alpha-nitrous- beta-naphthol.
The steel is dissolved with hydrochloric acid and the solution is oxidized with nitric acid. The trivalent iron and other interfering elements (chromium, copper, tin, bismuth, titanium, zirconium, silver, etc.) are separated by precipitating them with an aqueous suspension of zinc oxide. In the filtrate, free from iron, the cobalt is precipitated, under heat, with an acetic solution of alpha-nitroso-beta-naphthol. Said reagent first oxidizes the cobalt to trivalent, then reacts with it and forms the insoluble cobalti-nitroso-beta-naphthol which is filtered, washed and calcined. The cobalt oxide is weighed and possibly purified; manganese, aluminium, beryllium, arsenic, lead, antimony, zinc and phosphoric, arsenic and ammonium ions, and moderate quantities of nickel do not interfere in the determination. Solutions and reagents. Process for contents up to 10 percent cobalt. Calculation.
UNI 2959-1949 history
1949UNI 2959-1949 Procedures for chemical analysis of metallic materials. Determination of cobalt content f steels. Weight method with zinc oxide and with alpha-nitrous- beta-naphthol.