In the construction of 4 Steel Ladles of Arcelor Mittal is necessary to make a Heat Treatment of the entire Ladle. Due to its weight, about 60 Tons each, it is required to assemble a portable furnace in the manufacturing site to make the heat treatment in situ. In this case, a furnace of 8 meters high x 6 m x 6 m was installed. The heat treatment was carried out with 6 burners of high power fed by diesel oil. The work was done at the facilities of Talleres Gozón, in Avilés.