Kal-Do Process

a method of converting molten cast iron into steel without the consumption of fuel by blasting the cast iron from above with industrially pure oxygen in a rotary converter. The name “Kal-Do” came from the combination of the initial letters of the name Kalling (B. Railing, born 1892), the Swedish metallurgist who invented the process, and the name of the city of Domnarvet (Sweden), where the first such converter (27-ton capacity) was put into operation in 1956.

The converter is installed at an angle to the horizontal plane and rotates during the process around a longitudinal axis at 1–30 rpm. The main feature of the Kal-Do process, in comparison with the usual oxygen-converter process, is the simplicity of slag formation control by means of changing the rotation frequency of the converter. The Kal-Do process yields 45–48 percent scrap iron in the metal charge as a result of the reduction in the loss of heat with the waste gases.

A disadvantage of the Kal-Do process is the low output of theconverters.