YearUnited StatesBrazil
Quantity
(short tons)
ValueQuantity
(short tons)
Value
1902......   12$ 3,947
19031¹⁄₂$  570    7 1,947
1904 ¹⁄₂  200    9 3,935
19054  1600   18 5,506
1906 ¹⁄₂  248   26 5,041
1907    46   38 8,756
19080     0  27515,151
19091   250  11711,838
19100     0  12823,271
19111¹⁄₂  802   4516,169
19120     0   4314,772
19130     01,11954,767
19140     0  23714,903
19150     0    8 2,915
19160     0  10416,647

[104] Adapted from Mineral Resources, U. S., 1916, Part II, U. S. Geol. Survey, 1917, pp. 377-386.

SUMMARY

The principal use for zirconium ores at present is determined by the refractory properties of the oxide, zirconia. Refractory bricks and shapes for furnace linings, chemical ware, and other heat, acid, and alkali resisting articles are made of zirconia, and are finding a limited market.

The recent interest in zirconium is due to the remarkable properties which it is said to impart to steel. Its real worth, or function, in that direction is yet to be definitely determined, and tests conducted by the Bureau of Mines, Bureau of Standards and others are being made to ascertain the facts.

The best and most available source of supply at present is Brazil, where the natural oxide, baddeleyite, occurs in considerable quantities in the states of Minas Geraes and Sao Paulo. The deposits have not been explored sufficiently to make any reliable estimate of tonnage possible, but, judged from their surface showing, they are of vast extent. The silicate, zircon, is found in Brazil, India and in the United States in commercial quantities.

The important deposits of zirconium minerals are controlled by Brazil, Great Britain and the United States, but the actual ownership of many of the deposits is unknown. This is particularly true of the oxide ores.

CHAPTER XIII
MONAZITE, THORIUM, AND MESOTHORIUM
By R. B. Moore

USES OF MONAZITE

Practically the only use of monazite has been as a source of thorium salts. In extracting these, by-products are recovered, such as cerium, lanthanum, and other rare earths. Thorium salts are used almost exclusively for the manufacture of Welsbach mantles, which consist of 99 per cent. thorium oxide and 1 per cent. cerium oxide. For this use there is no known substitute. The one other use of thorium salts is in ordinary chemical laboratories, but this use is very limited. The fluoride and other salts of cerium are used in connection with the flaming arc, their presence giving increased luminosity.