Sometimes I do electric arc melts using a DC welder and carbon rods. But the problem is that *any* refractory melts or even vaporizes in the extreme heat of the arc. I searched on ebay / Amazon or other sites to MgO bricks but to no avail. MgO has a very high melting point: 2800 C. It is still below the arc temperture, but will wear much slower than the traditional '3000 F refractories'. Or can these made from powdered MgO (which is available) and some binder and water ?
Magnesia-alumina-silica refractories https://patents.google.com/patent/US2599184A/en?oq=US2599184A Some ratios that might help.
Don't know about EU availability but KT has wide selection of materials in brick. http://ktrefractories.com/Magnesia-Bricks.cfm Best, Kelly