PHOSPHATE ROCK
BY R. W. STONE
USES OF PHOSPHATE ROCK
Phosphate rock is chiefly used, after treatment with sulphuric acid,
as an ingredient of artificial fertilizers. A small quantity is finely
ground and used directly as fertilizer. Lesser quantities are used for
making phosphoric acid and phosphorus. Phosphorus plays an important
part in military operations, being used for incendiary bullets and
smoke screens. Phosphorus also is a common ingredient of matches and
the striking surface on boxes of safety matches, and it enters in small
proportion into phosphor-bronze, phosphor-copper and phosphor-tin.
=Substitutes.=--Substitutes for phosphate rock may be classed as
natural and artificial. Natural substitutes are phosphatic limestone;
other phosphate-bearing minerals, such as apatite, nelsonite, and
wavellite; guano; marl; animal excrement and bones. Artificial
substitutes include basic slag and manufactured compounds, like
ammonium phosphate.
GEOLOGICAL OCCURRENCE
Phosphate rock is a sedimentary deposit containing phosphate of lime.
It occurs as a hard rock interstratified with beds of sandstone, shale,
or other sediments; as amorphous nodular concretions or pebbles in
stream deposits; and as a residuum from the decomposition of phosphatic
dolomite or limestone, or other rocks containing phosphate of lime.
Another type of deposit commonly classed as phosphate rock is the
porous coralline or other limestone of tropical islands which has been
permeated with phosphate leached from guano.
Phosphate deposits of the western United States, Algeria, Tunis,
and Egypt are hard rock beds of the first type. Amorphous nodular
deposits occur in South Carolina, part of Florida, Wales, England,
Belgium, north-central and eastern France, and Russia. The deposits
in Tennessee, Kentucky, and some of those in Florida are residual.
Leached guano deposits are found on the islands of Aruba, Curacao, and
Sombrero, in the West Indies, and on Christmas, Ocean, Makatea, Angaur
and other islands in the Indian and South Pacific oceans.
The reserves in the United States are fairly well known and are
estimated at 6,000,000,000 tons. Reserves of high-grade rock in Algeria
and Tunis have been estimated at 300,000,000 tons. No information is at
hand regarding the quantity of phosphate rock in Egypt or in Europe,
except that Russia is believed to have 80,000,000 tons in one of its
fields. The deposits in the South Pacific islands are estimated at
70,000,000 tons. Before the war the world’s output of phosphate rock
was about 6,000,000 tons annually, of which about one-half was mined
in the United States. The next largest production is made in northern
Africa.
Phosphoric acid is derived also from apatite, a calcium phosphate that
occurs in veins. Apatite has been mined in the Province of Quebec,
Canada, and in Spain.
GEOGRAPHICAL DISTRIBUTION
In the Western Hemisphere phosphate rock is produced in the United
States, in Canada, the Dutch West Indies, and French Guiana, and occurs
in Peru and Chile.
=United States.=--The principal deposits of phosphate rock in the
United States are in Florida, South Carolina, Tennessee, Kentucky,
Arkansas, Montana, Idaho, Wyoming, and Utah. Although by far the
largest deposits are in the western states, those deposits yield less
than 1 per cent. of the whole because of the lack of a large near-by
market and because of high freight rates on the crude rock. It is not a
matter of common knowledge, but it is, nevertheless, a fact, that the
western rock phosphate deposits are so extensive as to be practically
inexhaustible, even if the entire world depended on them for its supply
of phosphate.
The _Florida_ phosphate deposits, which are the most extensively
developed in the United States, comprise three classes of
phosphate--hard rock, land pebble, and river pebble. The first is
highest grade, the second is produced in largest quantity, and the
third is not mined at present. The hard-rock deposits lie in a narrow
strip along the western part of the Florida peninsula from Suwanee
County to Pasco County, a distance of approximately 100 miles. The
land-pebble phosphate area, just east of Tampa, is about 30 miles long
and 10 miles wide. Sales of Florida phosphate declined tremendously
after 1913 through the restriction on exports by the war. In 1913
the sales were 2,500,000 tons, valued at $9,500,000, and in 1915 the
production was 1,350,000 tons, valued at $3,700,000.
_South Carolina_ produces land rock phosphate in the vicinity of
Charleston. River-pebble phosphate occurs in the same area but is not
mined. Some of the South Carolina output has been exported annually.
Sales decreased from 169,000 tons in 1911 to 83,000 in 1915, and the
value in the same years from $673,000 to $311,000.
_Tennessee_ deposits of rock phosphate are in the west-central part and
extreme northeast corner of the state; the latter have not been mined.
Three types are recognized and known by their colors as brown, blue,
and white rock; the last has not been mined recently. The brown rock
is sold under guarantee of 70 to 80 per cent. tricalcium phosphate;
the blue rock varies considerably in its phosphatic content. Sales of
Tennessee phosphate in 1914 were 483,000 tons, valued at $1,823,000; by
1915 they had fallen to 390,000 tons, valued at $1,328,000.
_Kentucky_ has been an insignificant producer of phosphate rock in
recent years. _Arkansas_ phosphate deposits are in the north-central
part of the state. The output is small.
Four western states possess enormous deposits of high-grade rock
phosphate, but their output is as yet insignificant, being only 3,000
to 5,000 tons a year. The producing states are Idaho, Utah, and
Wyoming. Montana is not a producer, although it contains extensive
deposits easy of access and close to rail transportation.
_Idaho_ has an unlimited supply of high-grade phosphate in the
southeast part of the state. A small quantity is mined in Bear Lake
County. The _Utah_ deposits are east of Great Salt Lake, in the Wasatch
and Uintah ranges, and east of Bear Lake. These deposits are extensive,
but the rock is leaner than the general run of the Idaho phosphate,
averaging nearer 60 per cent. than 80 per cent. tricalcium phosphate.
Western _Wyoming_ also is rich in rock phosphate, the deposits being
mostly in the Owl Creek, Wind River, Gros Ventre, and Salt River
ranges. Some of the beds are thick, carrying 80 per cent. tricalcium
phosphate, and extend for many miles. They constitute a reserve supply
that may be called inexhaustible. Small local demand for fertilizer and
lack of cheap transportation may retard for some years the development
of the great and rich western deposits.
An estimate of the quantity of rock phosphate available in the United
States was made several years ago and need not be revised to account
for that mined in the meantime. It is repeated here:
RESERVES OF PHOSPHATE ROCK IN THE UNITED STATES
Long tons
Florida 227,000,000
Tennessee 88,000,000
South Carolina 9,000,000
Kentucky 1,000,000
Arkansas 20,000,000
-----------
345,000,000
Western States: Montana, Idaho, Utah, and Wyoming 5,367,082,000
-------------
Total 5,712,082,000
=Canada.=--The principal phosphatic rock in Canada is apatite, which
occurs in workable quantity in two main districts--one in the Province
of _Ontario_, the other in the Province of _Quebec_. These deposits,
which were worked mainly by quarrying, are now practically abandoned.
Rock phosphate occurs in a thin bed near Banff, _Alberta_, but is not
used.
=South America.=--In Aruba and Curacao, islands of the _Dutch West
Indies_, off the coast of Venezuela, are deposits of phosphate rock,
from which a small quantity is mined and shipped to Europe. It is
reported that the output in 1914 was about 100,000 tons, averaging 85
to 90 per cent. of calcium phosphate.
In _Peru_, in the Department of Ica, is a deposit of nodular lime
phosphate, which is not used because of a local preference for guano.
A large, rich deposit of phosphate is reported in _Chile_, about 300
miles north of Valparaiso, but has not been developed as yet.
Phosphate deposits occur on the Island of Salut and on the Connetables,
close to the coast of _French Guiana_. The rock is exported.
=Europe.=--The high-grade phosphate deposits of _Belgium_ are
exhausted, only low-grade deposits remaining. The rock is found in
layers and pockets, and carries between 25 and 65 per cent. of bone
phosphate. The production from 1911 to 1913 averaged more than 200,000
tons annually.
The principal deposits in _France_ are in the Somme and Oise basins.
The best French deposits are higher grade than the Belgian, as they
carry 50 to 80 per cent. of bone phosphate, but they are nearly
exhausted, only low-grade material remaining. The production from 1910
to 1914 was about 300,000 tons annually.
Important deposits of phosphate rock in _Russia_ can be divided into
the northern, central, and southern groups. The deposits of the
southern group were the only ones exploited before the war. Their
output was about 25,000 tons a year--very small in comparison with
the size of the deposits, which are estimated to contain more than
1,500,000,000 tons. Some of the rock is high grade, carrying as much as
75 per cent. tricalcium phosphate, but the normal grade is about 50 per
cent.
The only deposits worked extensively in _Spain_ are apatite veins in
the Province of Caceras. After lying idle many years these deposits
were reopened and produced 28,000 tons in 1917.
Low-grade phosphate in the form of beds of nodules occurs in _England_,
and in _Wales_. The production has been slight because the deposits are
too small for commercial exploitation.
=Africa.=--The principal deposits of phosphate rock in _Tunis_ are the
Gafsa fields, in the southern half of the country. There phosphate
occurs in beds several feet thick, but only those carrying more than
58 per cent. phosphate of lime are exploited. The deposits can be
traced for several hundred miles, and constitute a reserve of hundreds
of millions of tons. Tunis now produces more phosphate than any
other foreign country, its annual output being between 1,500,000 and
2,000,000 tons, most of which goes to southern Europe.
The deposits of phosphate rock in _Algeria_ are continuations of those
in Tunis, the important mining districts being in eastern Algeria. The
production is over 500,000 tons a year, and the exported rock carries
58 to 68 per cent. of lime phosphate.
Extensive deposits of phosphate occur in _Egypt_, near the Red Sea,
in thin and irregular beds of the same geologic age (Eocene) as the
deposits in Tunis and Algeria. The best deposits average 70 per cent.
lime phosphate and the output in 1916 was 125,000 tons. There are
mines 20 miles from Port Safalga, and concessions 12 miles inland from
Kosseir and also at Sebaia, on the eastern bank of the Nile between
Keneh and Assouan. Beds of phosphate are found in other districts on
both sides of the Nile valley. Practically all the raw rock phosphate
produced contains 65 per cent. or more of tricalcium phosphate and is
exported mainly to Japan.
Deposits of phosphate occur 80 to 120 kilometers from the city of
_Tripoli_ in beds more than 1 meter thick. These beds probably are a
continuation of the phosphate deposits in southern Tunis.
Deposits of phosphate are reported in _Morocco_ 125 kilometers
south-southwest of Casa Blanca on the west coast and 70 kilometers from
the end of a railroad. These deposits are said to be comparable to the
Gafsa field, in Tunis.
It is reported that at Dielor, in _Senegal_, about the latitude of Cape
Verde, the westernmost point on the African coast, there is a phosphate
bed which is 2 meters thick to a depth of 64 meters. The rock carries
only 50 per cent. tricalcium phosphate, so it is not workable under
present conditions, especially in view of the abundant high-grade rock
in Algeria and Tunis.
Phosphates have been found in _Natal_, near Weenen, Ladysmith, and
Byrnetown, in the form of phosphatic shales and of nodules. The
percentage of tricalcium phosphate in the phosphatic shales is too low
for use in making superphosphates; the phosphatic nodules are of higher
grade but not abundant enough to be of value.
=Asia and Australasia.=--In the government of Uralsk, in southwestern
_Siberia_, bordering on the north end of the Caspian Sea, there is
reported to be 600,000,000 tons of phosphate rock. It is said that the
greater part of this material carries 17 to 20 per cent. phosphoric
acid, which is equivalent to 36 to 43 per cent. tricalcium phosphate.
The government of Turgai, which borders Uralsk on the east, is
reported to contain 67,000,000 tons of phosphate rock, most of which
carries 18 to 19 per cent. phosphoric acid, or about 40 per cent.
tricalcium phosphate. The highest-grade material reported is 24 per
cent. phosphoric acid, equivalent to about 52 per cent. tricalcium
phosphate. All the phosphate therefore is low grade. No production is
reported from either of the localities.
Low-grade phosphate rock, in sedimentary beds of considerable extent,
and high-grade vein deposits are reported in _Palestine_, on the east
side of the Jordan. The sedimentary deposits occur also on the west
side of the Jordan. The known reserves are about 3,500,000 tons. The
sedimentary deposits average about 48 per cent. and the vein deposits
77 per cent. tricalcium phosphate. As the vein material is suitable
for export, these deposits have been explored by a French company, but
available information indicates there has been no output.
_Islands in the North Pacific Ocean._--After the discovery of phosphate
rock on _Rasa Island_, 500 miles east of Formosa, a number of years
ago, a Japanese company was formed to exploit the deposits. The rock
is rich, carrying 75 per cent. phosphate of lime, and the reserves are
estimated at 2,800,000 tons. In 1915 Rasa Island yielded 50,000 tons. A
former German supply of phosphate is on _Angaur Island_, in the Pelew
group, east of the southern end of the Philippines. Reserves on this
island are estimated at 2,000,000 to 4,000,000 tons of phosphate rock,
mostly of high grade. Germany increased the output from 45,000 tons in
1910 to 90,000 tons in 1913. Japan has held this island since October,
1914, and is mining 30,000 tons or more phosphate annually.
Deposits of phosphate, consisting of replacements of dolomitic
coralline limestone, and phosphatic guano are reported on several other
islands in Oceania, as Baker and Fanning Islands, in _Polynesia_, and
Fais Island, in the _West Caroline Islands_. It is probable that on
other islands there are commercial deposits as yet undiscovered.
_Islands in Indian and South Pacific Oceans._--North of Adelaide,
in _Australia_, are pockety deposits of phosphate; they are without
regular stratification and are of varying quality. The annual output
has been 4,000 to 6,000 tons for several years. In the Otago district,
near Clarendon, _New Zealand_, beds of phosphate 3 to 12 feet thick
rest in pockets in limestone. There has been very little if any
production.
On _Christmas Island_ (Straits Settlements), which lies in the Indian
Ocean 190 miles south of Java, rock carrying 80 per cent. of bone
phosphate is quarried and shipped to Australia and Japan. The deposits
seem to be irregular, but are estimated to contain several million tons
of rock of very high grade. The island belongs to the government of
Singapore. Exploitation of the deposits by the British began in 1900.
Exports in 1913 were 150,000 tons.
Phosphate rock of high grade is mined on _Ocean Island_, in the
Gilbert Archipelago, between the Marshall and Solomon Islands, east
of New Guinea and north of New Zealand. On this and other so-called
coral islands in the equatorial belt which for ages have been sea-bird
rookeries, leachings from the guano have impregnated the limestone,
forming phosphate rock many feet deep. The deposits on this island
are said to be many millions of tons and are among the richest in the
world. They have been mined since 1901, and have produced as high
as 300,000 tons a year. In 1916 the output was 70,000 tons of rock
carrying about 85 per cent. tricalcium phosphate. The island is a
British possession.
Another British possession in the Gilbert Archipelago containing
phosphate rock is _Pleasant Island_, which is also known as Nauru, or
Ngaru, Island. The deposits are similar to those on Ocean and Christmas
Islands, being very high in calcium phosphate and low in iron and
alumina. Germany formerly owned this island, but it was taken over by
the British in 1917.
Makatea, near Tahiti, in the _Society Islands_, is estimated to
contain 10,000,000 tons of very high-grade phosphate rock, irregularly
distributed between reefs and pinnacles of dolomite. The deposits were
developed as recently as 1910 and yielded more than 300,000 tons before
1917. Some of the rock carries 85 per cent. lime phosphate. The island
is a French possession.
RECENT CHANGES AND DEVELOPMENTS
When the World War began, exports of phosphate rock from the United
States, ordinarily about 1,000,000 tons a year, were cut off and
the annual production of the United States fell from 3,000,000 tons
to 1,800,000 tons. There has been a strong recovery in the domestic
industry and if labor and transportation conditions improve there
should shortly be an annual production of nearly 3,000,000 tons for
domestic consumption, or as much phosphate rock for our own use as
formerly was produced for ourselves and a large export trade.
It is surmised that northern Africa will yield larger quantities in the
future than during the pre-war period. Production in Algeria, Tunis,
and Egypt was probably stimulated during the war on account of the
large reduction in the quantity of American rock sent to Europe.
Japan doubtless will make a large output from the German deposits in
Polynesia which came into her possession at the beginning of the war.
COMMERCIAL CONTROL
Ownership of the phosphate deposits in the United States is largely
domestic; some of the Florida hard-rock deposits are owned by French
and (before the war) German companies. The German-owned deposits were
taken over by the Custodian of Alien-Enemy Property, and have doubtless
passed into other hands. The phosphate deposits on Curacao, Dutch West
Indies, are worked by the Curacao Phosphate Mining Co., which ships the
output to England and Germany. Phosphate deposits in Algeria and Tunis
are exploited by French companies. Some of the companies work under
lease. La Compagnie des Phosphates de Paris and La Compagnie Algerienne
des Phosphates have been mentioned as engaged in these fields. Deposits
on the lower Nile and Red Sea are worked by the Egyptian Phosphate Co.,
a British concern, and by the Societa Egiziana per l’Estrazione de il
Commercio dei Phosphati, a company managed by Italians. It is reported
that much of the output goes to Japan. The Pacific Phosphate Co., Ltd.,
of London, operates under concession the phosphate deposits on Ocean
and Pleasant islands. Japanese companies are mining phosphate on Rasa
and Angaur islands.
POSITION OF LEADING NATIONS
The United States has the largest known deposits of phosphate rock
in the world, and, as before the war, can supply the needs of other
countries as well as her own. Since mining began about 55,000,000 tons
have been mined, or less than 1 per cent. of reserves. Great Britain
possesses phosphate in Egypt and on Christmas, Ocean and Pleasant
islands, and has imported from the United States and probably from
northern Africa. France and the other Mediterranean countries have an
ample supply in Algeria and Tunis. Germany formerly possessed rich
deposits of phosphate on Angaur Island, in the Pelew group, Polynesia,
and on Pleasant and Ocean islands, but so far as known now lacks a
source of supply. Japan has a large supply of high-grade phosphate at
her disposal on Rasa and Angaur islands.
SUMMARY
The principal use of phosphate rock is as an ingredient of fertilizers.
Lesser quantities are consumed in the manufacture of phosphoric acid,
in phosphorus used in military operations, in the manufacture of
matches, and in metallurgy. Both natural and artificial substitutes are
available for many of the uses of phosphate rock.
Phosphate rock is a sedimentary deposit containing phosphate of lime.
It occurs as a hard rock between beds of sandstone or shale, as
amorphous nodular phosphates in stream deposits, and as a residuum
from the decomposition of phosphatic dolomite, limestone, and other
phosphate-bearing rocks. The porous limestone of tropical islands,
where it is permeated with phosphate leached from guano, is commonly
classed as phosphate rock.
The phosphate rock deposits of present commercial importance are
situated in the United States, Algeria, Tunis, Egypt, and the islands
of the Indian and South Pacific oceans, the United States possessing
by far the largest reserves. Smaller deposits, either undeveloped or
nearly exhausted, are in Canada, Venezuela, Chile, Belgium, France,
Russia, England, Spain, South Australia, and New Zealand.
During the war the exports of phosphate rock from the United States
decreased greatly. With the return to normal conditions, however, the
United States should experience little difficulty in becoming once more
the principal source of phosphate rock.
The principal phosphate-rock deposits are controlled politically by the
United States, France (Algeria and Tunis), and Great Britain (Egypt). A
number of phosphate-bearing islands in the Pacific Ocean were owned by
Germany before the war, but have been seized by Great Britain and Japan.
The commercial control of the deposits of the United States is mainly
in the hands of Americans, although German (before the war) and French
interests own some of the Florida hard-rock deposits. The deposits of
Algeria and Tunis are controlled by French companies. The Egyptian
deposits are controlled by two companies, one British and the other
Italian.
Germany will be without a source of supply under her own control now
that she has lost her colonies.