Description
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Cerium is a lanthanide that is a silvery white solid in its natural state. It is a soft lanthanide, and has the longest liquid range out of all the other non-radioactive elements. It has an atomic weight of 140.116, a melting point of 1463 °F, and a boiling point of 6229 °F. Some common uses of cerium include: in the manufacture process of aluminum alloys, as a component in stainless steel, as a component in permanent magnets, as a component of lighter flint, and in carbon-arc lighting.
Isolation
Cerium is the most abundant rare earth elements and occurs in a number of minerals. Isolation processes can be used to extract cerium from these minerals.
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While cerium occurs in many minerals including, allanite, monazite, bastnasite, hydroxylbastnasite, rhabdophane and zircon, only monazite and bastnasite are used as a source of cerium. Cerium is not normally completely isolated, as it is used with a number of lanthanides that it occurs with in nature. The isolation of cerium from these other elements is complex and requires a number of steps; due to the complexity of cerium isolation, the separation process is only performed for commercial uses and not on a small scale laboratory basis.
During the first step in cerium isolation, the metals are extracted out of the mineral compounds as a salt through the use of sulphuric acid, hydrochloric acid, and sodium hydroxide. The ion of cerium is easily hydrolyzed and can be precipitated out as a salt through the addition of an oxidizing agent. Further electrolysis using heated, liquid, cerium chloride and sodium chloride in a graphite cell produces pure cerium and chlorine gas.