Molten pig iron and scrap are loaded in the converter. The scrap usually is rusty and contains oxygen, so some of the rust reacts with the pig iron, burning the carbon away and creating heat which melts the scrap. Once all scrap has melted, a special pipe called "oxygen lance" is lowered in the pig iron, and a very fast and sharp blow of oxygen is blasted in. The oxygen burns all the carbon away and mixes the liquid steel thoroughly. Once all carbon has been burned away, some extra carbon is inserted to raise the contents to desired level. The result is liquid steel, which is then tapped away and taken to rolling mill to produce steel products.