the Continental Shelf containing 0.5 to 1 .5 per cent ilmenite and from 0.2 to 0.4 per cent zircon seems 

 reasonable. The concentrations of rutile and monazite will be much less. Most of the inferred deposits 

 will probably be in water 30 to 120 feet deep. These inferred grades and volumes are too low to be 

 presently competitive with domestic and foreign titanium ores. 



YTTRIUM 



Uses. The major and only commercial use of yttrium is in yttrium-iron garnets called "yigs" in the 

 electronics industry. These serve as filters for selecting or tuning microwaves. Other potential 

 commercial uses are in nuclear reactors and as an additive promoting the formation of nodular graphite 

 in ductile cast iron. 



Present levels of utilization of yttrium in short tons. 



World (1966 production, mostly yttrium contained in concentrates, estimated) 315 



United States (1966 demand, based on sales of purified oxide) 50 



Ranges of demand projections to the year 2000. 



Prospective supplies and prices. Domestic reserves of the yttrium-bearing minerals (monazite and 

 xenotime in the southeast and monazite and euxenite in the northwest) are conservatively estimated 

 in excess of 2,000 tons of contained yttrium. These sources would suffice for U.S. demand until nearly 

 1985 at a price of about $64 per pound of contained yttrium (based on a current price of about $50 per 

 pound of refined oxide). Current U.S. demand relies heavily on imports of crude yttrium salts which are 

 by-products of uranium ore processing. Supplies from the Canadian source, or possibly from a similar 

 domestic source, added to domestic southeast and northwest mineral deposits, are adequate to meet 

 domestic demand to the year 2000. If needed, extremely large quantities could be recovered at markedly 

 higher prices as by-products from phosphate deposits throughout the world. 



Possible substitute materials. In the electronics industry cheaper and more plentiful materials such as 

 the spinel-type ferrite compounds can substitute for yttrium-iron garnets, but they give less satisfactory 

 performance. 



Potential from marine sources. Yttrium is always found in association with rare earths. It is 

 concentrated mainly in xenotime (essentially an yttrium phosphate) and to a lesser extent in monazite 

 and other minerals. It is sometimes concentrated in apatite the principal mineral of phosphorite. The 

 potential for yttrium production thus depends on the abundance of xenotime and monazite in black 

 sands (see section on monazite). 



VlI-161 



