<P> As of 2007, the high demand for neodymium has made it profitable to remove all of the heavier lanthanides and neodymium (and sometimes all of the praseodymium as well) from the natural - abundance lanthanide mixture for separate sale and to include only La - Ce - Pr or La - Ce in the most economical forms of mischmetal . 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 . As of 2007 mischmetal is typically priced at less than 10 USD per kilogram, and the underlying rare - earth chloride mixtures are typically less than 5 USD / kg . </P> <P> Mischmetal is used in the preparation of virtually all rare - earth elements . This is because such elements are nearly identical in most chemical processes, meaning that ordinary extraction processes do not distinguish them . 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 . Such processes later informed Marie Curie in her search for new elements . </P> <P> Traces of a cerium and lanthanum mischmetal are sometimes added to the Galfan galvanising process for steel wire . This is a zinc and 5 - 10% aluminium coating, with traces of mischmetal . </P>

Which of the following transition metal is present in misch metal