42
OUE MINERAL RESERVES.
owing to the distance the mineral must be hauled to a railroad, while
smaller mines close to railroad stations are being worked.
For certain purposes magnesite is used raw, and for other purposes
it is calcined, and the imports include both kinds. As in the manufacture
of cement, for example, freshly calcined magnesite seems to
be superior to old calcined material, there would seem to be a field
for more extensive calcining and grinding in our own country,
entirely irrespective of the source of the material.
FLUORSPAR.
The fluorspar industry of the United States has shown a steady
growth from a production of 4,000 short tons in 1884 to 115,580 tons,
valued at $736,286, in 1913. This notable gain has been conditioned
largely by the growth of the open-hearth process of steel manufacture,
which absorbs about 80 per cent of the fluorspar produced.
Fluorspar is used also as a flux in blast furnaces, iron foundries, and
silver, copper, and lead smelters; in the manufacture of fluorides of
iron and manganese for steel fluxing; in the manufacture of glass,
enameled, and sanitary ware and of hydrofluoric acid; in the production
of aluminum ; in the electrolytic refining of antimony and
lead ; and for many other purposes.
The increase in the home production and the imposition of a tariff
on fluorspar in 1909 have resulted in a marked decrease in the
amount brought in from foreign countries, and in 1913 only 22,682
short tons was imported, compared with the 115,580 tons produced
at home. The imports come almost entirely from Great Britain and
amount to over 55 per cent of the total English production of this
mineral. The English product entering at New York is able to compete
with domestic " spar ” as far west as Pittsburgh.
There can be no question of the adequacy of the American supply
to meet all demands in case the English supply is cut off. In 1913
the output came from Illinois, Kentucky, New Mexico, Colorado,
New Hampshire, and Arizona, named in the order of yield. Furthermore,
the foreign spar is of lower grade than the mechanically
treated spar from Illinois and Kentucky, and as fluorspar is of value
chiefly according to its purity, purchasers find that the purer American
spar is more efficient and consequently cheaper in the end.
STRONTIUM.
The Geological Survey has received in the last few weeks inquiries
regarding American occurrences of strontium minerals. Many of
the domestic occurrences are of minor extent and most of them are
of little commercial value under ordinary conditions. The two
strontium minerals of commercial importance are celestite (SrSO,)
