Abstract: A probe for detecting wear of a refractory wall, including plural sheathed probe elements of different lengths each consisting of a pair of high melting point wires disposed in parallel and insulated from each other except at least the fore end portions of the wires which form a normally closed or normally open sensing point, a sheath enclosure accommodating the probe elements such that the sensing points of the respective probe elements are located at different positions along the length of the sheath enclosure and holding the probe elements in parallel relation and out of contact with each other, and a number of dummy elements formed of a material similar to the probe elements and connected to the fore ends thereof in a manner to complement the lengths of the shorter of the probe elements. There is also disclosed a detection circuit for monitoring wear of a refractory wall in a molten metal processing apparatus in a simple and accurate manner by the use of the probe.

Abstract: A blowing tuyere to be embedded in a bottom of side wall of a molten metal bath container for blowing a gas thereinto, the tuyere including a cylindrical core body fixedly located at the center of the tuyere and an outer tube fixed concentrically around the core body with a gap of a predetermined width to form an annular blowing passage therebetween.

Abstract: A method for stably refining high carbon steel by top and bottom blown converter refining in which the entire quantity or part of refining pure oxygen is blown onto molten iron through a top blowing lance nozzle while blowing an inert gas into the converter through a nozzle at the bottom thereof, and wherein the bottom blown inert gas is fed at a rate less than 0.09 Nm.sup.3 /min.multidot.ton during the blowing and/or at a rate less than 0.03 Nm.sup.3 /min.multidot.ton in a controlling stage immediately after turndown.