Studies on Rapid Analysis of Iron and Steel by Photoelectric Photometry (V). Rapid Photometric Determination of Small amounts of Vanadium in Iron and Steel

Abstract

The author studied the photometric methods for rapid and accurate determination of small amounts of vanadium in iron and steel and obtained good results by the following procedure: when vanadium content is more than 0.1%, dissolve the sample in perchloric acid and nitric acid evaporate to fume, add hydrogen peroxide, add hydrofluoric acid to eliminate the interference of titanium and measure the extinction. This method requires about ten minutes, and Cr up to about 0.7%, Ni up to about 5%, W up to about 0.6%, and Mo up to about 0.5% were found to have no influence. In the presence of 0.001 to 0.07% vanadium, dissolve the sample in sulphuric acid and hydrogen peroxide, expel the hydrogen peroxide by boiling, add potassium permanganate to decompose the carbide, reduce the excess of permanganate with hydrogen peroxide, boil off hydrogen peroxide, cool to the room temperature, oxidize vanadyl ion to vanadate with potassium permanganate, reduce the excess of permanganate with urea and sodium nitrite, add sulphuric acid and phosphoric acid, add diphenylamine at about 40°, mix well, dilute, and measure the extinction. This method requires only twelve to thirteen minutes and W up to about 0.1% was found to have no influence.