A dynamic mechanism of gas absorption in the furnace of the vacuum fusion analysis

Abstract

A dynamic behavior of both extracted gas and metal vapor evolved from fused steel sample (NBS#1041) in the vacuum fusion analysis was studied. Metal vapor was trapped on a moving surface of an alkalineless glass tape which passes by a 10 mm wide window at a speed of 2 mm per sec. Iron and manganese deposited on the surface of the tape were extracted in an ethanolamine-NaOH solution and determined by a polarographic method.A variation in the pressure change of the extracted gas was recorded with a Pirani gauge at an outlet of the extraction pump. And these results were compared with the analytical values of oxygen obtained by an ordinary method [See Bunseki Kagaku, 14, 540 (1965) ].The difference in the extent of gas absorption in the successive analyses was closely related to the degree of the overlap with the metal vapor which at first evolved within 4 to 20 sec after the addition of a sample in a crucible.The gas absorption in a vacuum fusion analysis was proved to be reduced by such a method using a metal bath or graphite capsules, which prevent the overlap of the evolution of gas and metal vapor.