Process in which oxygen is blown downwards at high velocity through a watercooled lance onto the surface of the hot metal contained in a basic lined vessel. To offset the intense heat produced, coolant materials are added with the original charge. These may be iron ore, sinter, or roll scale, but usually steel scrap is the main material used. As much as 26% of scrap may be used. After about 20 min, the charge is converted into liquid steel. During the process, tests and analyses are made and materials may be added to bring the metal to the required grade and temperature.