Bastnasite samarium

As with other rare earth elements, the primary sources of samarium are the mineral monazite and bastnasite. It is also found in samarskite, cerite, orthite, ytterbite, and fluorspar. 

Relatively inexpensive samarium depends upon the mischmetal production and the production of other separated light lanthanides from the monazite and bastnasite ores for other products. In the preparation of mischmetal samarium is naturally concentrated in the slag because it is only reduced to the divalent state during electrolysis while the other rare earths are reduced to metal at the cathode. The samarium is cheaply recovered from the slag. In the early 1980 s when mischmetal production peaked, the total amount of samarium available from both the mischmetal production and as a by-product for other separated rare earths was about 400 tons per year. The production of samarium could be increased but it would be much more expensive since it would have to be separated from the ores for itself and bear the burden of the separation costs since the other lanthanides would be surplus materials. 

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