METHOD OF AND DEVICE FOR MEASURING OXYGEN ACTIVITY IN SLAG AND CONSUMABLE TYPE CRUCIBLE USED FOR SAID DEVICE

摘要

This invention relates to a method and device permitting measurement of oxygen activity in the molten pig iron slag and molten steel slag with high precision. According to the conventional method of measurement depending on the oxygen-concentration cell composed of a one-end-closed tube type solid electrolyte fixed to the tip of the probe, having a contrasting platinum electrode wound around the outer surface thereof, and located directly in the molten slag layer, positioning of the cell in the flowing slag is difficult and insufficient contact of the contrasting electrode with the slag layer is caused on account of thermal contraction of the electroyte resulting from heat of the slag, whereby errors possibly occur in measurement. Unlike the direct measurement of oxygen activity in the slag, this invention provides a method in which a specific metal whose oxygen activity equilibrates with that of the slag when brought into contact with the slag is contained in the same vessel together with the slag and oxygen activity in the specific metal is measured for indirect measurement of oxygen activity in the slag, whereby the problem resulting from insufficient contact of the solid electrolyte with the contrasting electrode can be solved and measurement of oxygen activity in the slag with high precision is ensured.