What is "mitis casting"

Mitis casting \Mi"tis cast`ing\ [Perh. fr. L. mitis mild.] A process, invented by P. Ostberg, for producing malleable iron castings by melting wrought iron, to which from 0.05 to 0.1 per cent of aluminum is added to lower the melting point, usually in a petroleum furnace, keeping the molten metal at the bubbling point until it becomes quiet, and then pouring the molten metal into a mold lined with a special mixture consisting essentially of molasses and ground burnt fire clay; also, a casting made by this process; -- called also wrought-iron casting.