GB1235091A - Process and apparatus for measuring in a continuous manner the oxygen in a molten metal - Google Patents

Abstract

1,235,091. Measuring oxygen content in liquid metals. METALLURGIE HOBOKEN, RST. INTERNATIONAL METALS Ltd. and FREDERICK DENYS RICHARDSON. Jan. 1, 1969 [Feb.9, 1968j, No.9/69. Heading G1N. A cell for measuring the oxygen content of liquid copper or lead comprises a stabilized zirconia solid electrolyte tube 2 surrounded by a protective tubular sheath 3 which also acts as an electrode for contacting the liquid metal 1. A reference gas, e.g. air, of known oxygen content is passed over the inner surface of the zirconia tube. The sheath 3 is cemented to the tube 2, the cement 4 containing a refractor ring 14 or refractory fibrous material. For use with copper, the sheath may be made of a Cr + Al 2 O 3 cermet, a refractory steel such as ferritic steel containing chrome, or an alloy of iron and aluminium. A copper block 8 (which melts in use) having a gas escape bore 18 may be held by a screw 19 to the lower end of the sheath 3 to give protection from slag during insertion and to reduce thermal shock. For use with lead, the sheath may be made of iron. The upper extension is of stainless steel. As shown, the inner electrode is a platinum or platinum rhodium wire 7 running through the reference gas inlet tube 5 which is made of aluminous refractory material. Alternatively, Fig. 2 (not shown), the bottom of the zirconia tube may contain silver (which melts in use) into which dips a stainless steel tube serving as the electrode and also as the reference gas inlet tube, the lower end of the tube being cut obliquely to avoid bubbling. A cooling jacket may surround the upper part of the sheath. The apparatus may be fixed to a wall of a casting ladle or a trough through which the metal is flowing.