3735

Iowa State University and Ames Laboratory researchers have developed a method of preparing rare earth-silicon alloys using carbon as a reducing agent instead of calcium that is less expensive than the traditional methods and more environmentally friendly.

 

The present invention provides a one-step process whereby rare earth-containing oxides are reduced in the presence of carbon and a reactant element, silicon, resulting in an intermediate master alloy made of a majority of the rare earth element and a small amount of silicon. The use of carbon as the reducing agent makes this process a low-cost one when compared to processes that use calcium as the reducing agent and the production of calcium fluoride or calcium chloride slag is eliminated, additionally lowering cleanup costs. The invention also has lower energy costs compared to techniques that use electrolysis to generate the desired rare earth metal. The intermediate master alloy produced can then be used, for example, to make nickel metal hydride batteries or as a reducing agent for preparing samarium metal for making samarium-cobalt permanent magnets. The principles of the invention can be applied to other rare earth oxides as well as mischmetal-containing oxides.

• Lower cost

• Many potential uses

• More environmentally friendly

• Corrosion resistant

Rare earth master alloys, rare earth magnets, nickel metal hydride batteries