At a few places along the coast strips of monazite-bearing sands lie directly behind the government land, and some of these might be worked profitably were it not for the fact that it has been difficult to prove to the federal government that these sands were not taken from the nearby government land. One French concern has exploited such lands in the State of Rio de Janeiro. Along the banks of the large rivers, such as Parahyba, there are great quantities of black sands with traces of monazite. Near Sapucaia such deposits have been worked by a French concern. Many of the inland deposits can not be exploited on account of the expense of transportation of the products, as the deposits are many miles from a railroad.
India.
—India is the newest source of monazite sands, the deposits lying on the sea beach like those in Brazil. The deposits are in the Travancore district near the southwestern end of the Hindustan peninsula. Very little information is available concerning these deposits.
CHANGES IN TREATMENT PRACTICE
The general method of treatment employed until quite recently has involved leaching the concentrate with concentrated sulphuric acid, thus getting the thorium, cerium, and other rare earths in solution and separating them from the silica, zircon, ilmenite and other insoluble products. From this stage different companies used slight variations in practice, such variations being kept strictly secret, although they all involved the precipitation of the thorium as oxalate by means of oxalic acid.
At the outbreak of the war the price of sulphuric acid went to four or five times the original cost, and the increased price of oxalic acid was practically prohibitive. Consequently the manufacturing companies had to change their entire procedure and to use chemicals that they could obtain at a reasonable price. In this difficult undertaking the companies were successful, and at least one company devised a process that was considerably more efficient than the old one.
At present mesothorium is being produced as a by-product by the Lindsay Light Co. and the Welsbach Co., the process used by the latter company having been originated by the Colorado Station of the United States Bureau of Mines. This process is cheap and extremely efficient, and will no doubt enable the Welsbach Co. to compete commercially with any other manufacturer of mesothorium. Of course as the process was developed by the Bureau of Mines it will ultimately be made available for anyone, but as mesothorium can only be made at a profit as a by-product of thorium nitrate, anyone who manufacturers mesothorium must first establish a thorium industry.
POLITICAL CONTROL
The important monazite resources of the world are controlled politically by three nations: the United States, Great Britain (India) and Brazil. The deposits of the United States, in normal times, probably can not be worked successfully in competition with the foreign deposits without the protection of a high tariff.