Mischmetal magnesium alloy

In the early 1970 s another major, but short-term application developed based on the pyrophoric nature of cerium/mischmetal. This use involved the manufacture of a mischmetal-magnesium alloy as a liner for artillery shells, which would burn with an intense heat upon impact. These shells were primarily intended for antitank warfare. Although the mischmetal production for these shell liners was high, it only lasted about 18 months. 

An alternative commercial form of a metallic mixed lanthanide-containing material is rare-earth siUcide [68476-89-1/, produced in a submerged electric-arc furnace by the direct reduction of ore concentrate, bastnasite, iron ore, and quart2. The resulting alloy is approximately 1/3 mischmetal, 1/3 sihcon, and 1/3 iron. In addition there are some ferro-alloys, such as magnesium—ferrosilicons, derived from cerium concentrate, that contain a few percent of cerium. The consumption of metallic cerium is overwhelmingly in the mixed lanthanide form in ferrous metallurgy. 

In view of the poor magnesium recoveries (and the associated pyrotechnics) and the present availability of desulfurized base iron, efforts have been made to establish the rare earths as the primary nodulizers (13). After all, Morrogh originally produced nodular iron by the use of mischmetal. The rare earths are more dense than the liquid base irons (p=6.6 gm/cm for cerium (14), whereas p 6.2 gm/cm for gray irons above the liquidus (15)). They also are liquid at iron founding temperatures. As a result, there is not a problem with pyrotechnics and alloy flotation can be minimized. Recoveries of the rare earths in the iron have been found to be high. 

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