电渣重熔（Electro Slag Remelting），也叫电渣铸锭、电渣精炼，是利用电流通过熔渣所产生的热进行金属精炼的方法。被熔炼的金属预先制成电极，在电极与水冷结晶器之间通过电流时，使熔渣产生高温，金属电极按一定速度送入熔渣，在其中逐步熔化、沉积、凝固而成铸锭。熔化过程中，金属溶液被熔渣有效净化。在金属凝固过程中，能造成有利的结晶方向，使铸件的性能有很大提高，主要用于获得国防工业、高技术方面的特殊钢或合金。

Electroslag remelting (ESR), also known as electro-flux remelting, is a process of remelting and refining steel and other alloys for mission-critical applications in aircraft, thermal power stations, nuclear power plants, military technology, et al.

The electroslag remelting (ESR) process is used to remelt and refine steels and various super-alloys, resulting in high-quality ingots. This process can be started up through vacuum induction melting. The ESR process uses the as-cast alloy as a consumable electrode. Electric current (generally AC) is passed between the electrode and the new ingot, which is formed in the bottom of a water-cooled copper mold. The new ingot is covered in an engineered slag that is superheated by the electric current. The electrode tip is slowly melted from contact with the slag. These metal droplets travel through the slag to the bottom of the water-cooled mold and slowly freeze as the ingot is directionally solidified upwards from the bottom of the mold. The slag pool floats above the refined alloy, continuously floating upwards as the alloy solidifies. The molten metal is cleaned of impurities that chemically react with the slag or otherwise float to the top of the molten pool as the molten droplets pass through the slag.