A cooling plate for a metallurgical furnace comprising a body (12) with a front face (18) and an opposite rear face (20), the body having at least one coolant channel (14) therein; the front face (18) being turned towards the furnace interior and preferably comprises alternating ribs (22) and grooves (24). The cooling plate includes wear detection means comprising: a plurality of closed pressure chambers (26, 28) distributed at different locations in said body, said pressure chambers being positioned at predetermined depths below the front face (18) of said body; and a pressure sensor (30) associated with each pressure chamber (26, 28) in order to detect a deviation from a reference pressure inside said pressure chamber when the latter becomes open due to wear out of said body.

The invention concerns a process for detecting water leaks in smelting furnaces (2; 4) or in metal or alloy treatment plants, comprising the following steps: (i) providing at least one smelting furnace (2; 4), or at least one metal or alloy treatment plant provided with a water cooling system (5) and being connected to a process fume exhaust system; (ii) mixing in the cooling water a tracer chemical which is volatile in the event of water leakage together with the exhaust gases and which is suitable to be detected by an analysis system of the exhaust gases; and (iii) detecting said tracer chemical contained in the exhaust gases by said analysis system comprised in said process fume exhaust plant, wherein said tracer chemical is deuterated water. The invention further refers to a Plant for the production of metals or alloys.