Ductile iron can be most efficiently produced by using specially designed equipment. FMS offer ductile iron treatment ladles and systems for most processes including:
Although this is the simplest process, a correctly designed ladle can still offer better performance and cost savings over using an oversize standard ladle. The deep treatment ladle shell is usually designed to have a ratio of 2:1 for the height to diameter. The ladle also incorporates an extended freeboard to contain the reaction.
An improvement on the sandwich method, the tundish greatly reduces the fume, increases the Mg yield and reduces both the slag formation and the temperature loss. Probably the most cost effective ductile iron process for most foundries. The savings due to reduced amount of additives necessary and the energy savings possible lead to a short payback period.
The tundish ladle is available in a number of standard designs:
The tundish is removed after each treatment and before the ladle is rotated.
The tundish is fixed to the top of the ladle, either by bolts or clamps, for the duration of the operating shift and offers improved performance over the loose tundish ladle.
This is a variation on the loose tundish ladle and is designed to eliminate the handling problems associated with the loose tundish between treatment cycles.
This is a similar process to the tundish method with a covered ladle fitted with a specially design teapot spout. The ladle is both filled and emptied via the teapot spout, giving the performance of a fixed tundish ladle but with a more compact size.
Other treatment ladles for wire feed and plunging bell processes are also available.