Mischmetal

A typical composition includes approximately 55% cerium, 25% lanthanum, and 15~18% neodymium, with traces of other rare earth metals totaling 95% lanthanides, plus 5% iron.

The ore was cracked by reaction at high temperature with either concentrated sulfuric acid or sodium hydroxide.

Any samarium content of the ore tended not to be reduced to the metal, but accumulated in the molten halide, from which it could later be profitably isolated.

The light lanthanides are so similar in their metallurgical properties, that any application for which the original composition would have been suitable, would be equally well served by these truncated mixtures.

The traditional "rare-earth chloride", as a commodity chemical, was also used to extract the individual rare earths by companies that did not wish to process the ores directly.

Highly specialized processes, such as those developed by Carl Auer von Welsbach, exploit subtle differences in solubility to separate mischmetal into its constituent elements, with each step producing only an incremental change in composition.