GRAPHITE
BY H. G. FERGUSON, FRANK F. GROUT, AND GEORGE D. DUB
USES OF GRAPHITE
Graphite is produced in several grades which are adapted to different
purposes. Amorphous graphite is a trade term applied to non-crystalline
or very fine-grained graphite of varying degrees of purity. If
crystalline graphite is produced in flakes or scales, it is flake
graphite; but if mined from veins it may have other forms, and be known
as vein graphite. Lump, chip, and dust refer to products of larger
crystals of Ceylon vein graphite more or less broken in mining and
treatment. All those three are spoken of as crystalline. Artificial
graphite, made from coal or other carbonaceous matter, resembles the
amorphous variety.
Graphite for crucible use must be high grade, either lump, chip, or
flake graphite, contain at least 85 per cent. graphitic carbon and be
free from fluxing impurities. Vein graphite is considered especially
desirable for this use. Possibly the increased development of the
electric furnace in the steel industry and in non-ferrous metallurgy
will reduce the demand for crucibles. Both crystalline and amorphous
graphite are used as lubricants. For this purpose the graphite should
be free from quartz or other gritty impurities. For foundry facings,
amorphous graphite and Ceylon dust are chiefly used; high-grade
material is not required. For the better grades of pencils, mixtures
of crystalline and high-grade amorphous are needed; for the poorer
grades, amorphous is used alone. The graphite used as polish for high
explosives is amorphous. This use does not consume large amounts. For
the manufacture of electrodes, artificial graphite is considered the
most suitable. The graphite used as dry battery filler may be either
amorphous, artificial or crystalline. Pure material is required, but
the size of grain is not a factor.
Amorphous graphite is used in boiler compounds for preventing hard
scale; pure material is not essential. For paints, either amorphous or
crystalline graphite may be used and need not be high grade.
For stove polish and shoe polish amorphous graphite is chiefly used;
imperial graphite is used as an adulterant in fertilizers, to give the
desired dark color.
For amorphous graphite and dust, artificial graphite may be
substituted. For crystalline graphite used in the manufacture of
crucibles no good substitute is available. However, the use of
electric furnaces or open-flame furnaces in non-ferrous metallurgy may
reduce the need of crucibles. For lubricating, mica is used in somewhat
the same way as graphite but is much inferior. Many other boiler
compounds serve the same purpose as graphite. In paints, lampblack is a
substitute. Talc is used in connection with and as a partial substitute
for graphite in foundry work. Blast furnace graphite, or “kish,” offers
possibilities as a substitute for flake graphite for lubricating
purposes. Developments along this line, however, have not proceeded far
enough to be conclusive.
GEOLOGICAL OCCURRENCE
Amorphous graphite may occur wherever coal or other carbonaceous beds
have undergone regional or igneous metamorphism. Crystalline graphite
has two principal geologic occurrences, as flakes in schists and
as larger crystals in veins. Flake graphite in schists is usually
associated with granitic intrusions which appear to have aided
recrystallization of original carbonaceous material in the sediments.
Vein graphite in commercial quantities is rather rare. It is found
associated with granitic intrusives and generally with graphitic
sediments containing the flake variety. Such rocks in most parts of the
world have not been prospected enough to make sure that all important
bodies of graphite are discovered.
WORLD CAPACITY FOR GRAPHITE PRODUCTION
In the order of their importance the following table lists the various
countries which produce graphite or in which graphite deposits have
been reported:
=1. Crystalline Graphite=
_A. Vein Graphite_
Ceylon--could produce up to 35,000 short tons per year, all
grades.
United States--small production from Montana.
Canada--small amount recently produced.
_B. Flake Graphite_
Madagascar--could produce up to nearly 50,000 short tons per
year.
Bavaria--has averaged 12,000 tons for several pre-war years,
and greatly increased production during the war. Produced
40,000 metric tons in 1917.
United States--could readily produce 4,000 tons of flake
exclusive of dust.
Canada--could probably produce 1,200 tons of flake exclusive
of dust.
Spain--deposits being developed.
Norway--new development reported.
Roumania--important deposits recently reported.
Japan--has not produced very much.
Sweden--very small production.
Transvaal--very small production, locally consumed.
Greenland}--large deposits reported. Very little development.
Brazil }
German East Africa (former)--deposits of supposed large extent
reported.
=2. Amorphous Graphite=
German Austria }--has long produced large amount of graphite
Czecko-Slovakia} annually.
Chosen--could probably produce 12,000 tons per annum.
Italy--could probably produce 12,000 tons per annum.
Mexico--could probably produce 6,000 tons per annum.
United States--could readily produce 6,000 tons natural and
6,000 tons artificial amorphous graphite.
Spain--could probably produce 1,000 tons annually.
France--could probably produce 1,000 tons annually.
Siberia--large amount available but undeveloped.
Rhodesia--local supply.
Brazil--supply undeveloped.
Queensland--supply undeveloped.
FUTURE DEVELOPMENTS
Although no definite data are available, it is believed that Ceylon can
not produce much longer at the present rate, and it is possible that
the virtual exhaustion of the deposits is not far distant. Madagascar
is capable of greatly increased production. It is doubtful if American
deposits with less than 5 per cent. graphite will be able to meet free
competition from Madagascar, where over 20 per cent. of the rock as
mined is graphite. Too little is known of the Greenland and Brazilian
deposits to hazard a guess as to their future importance, but it is
reported that immense reserves exist in Greenland. The German flake
deposits will hardly survive free competition from Madagascar, unless
modern methods are introduced. Amorphous graphite will probably be
chiefly produced, as at present, by Austria, Bohemia, Mexico and
Chosen. Mexico and Chosen are likely to supply most of the pencil
graphite of the world. Increased production of artificial graphite
may reduce the demand for amorphous graphite. In 1918, notices in
the German technical press told of the discovery of immense deposits
of flake graphite in Roumania. These were to be worked jointly by
the German and Austrian governments under a 75 year lease from the
Roumanian government. The outcome of the war of course annulled this
arrangement.
Vein graphite (that is, Ceylon graphite) is preferred for crucible
manufacture, but increasing amounts of flake are being used
successfully. European manufacturers seem to use flake almost
exclusively; and American manufacturers will no doubt find it possible,
if necessary. Increasing amounts of amorphous graphite are being
employed for various industrial uses, chiefly foundry facings. The
development of the electric steel furnace, by reducing the use of
crucibles, may tend in some degree to reduce the difference in value
between crystalline and amorphous graphite.
POLITICAL AND COMMERCIAL CONTROL
Amorphous graphite is so widely distributed that no serious difficulty
is likely to be encountered by any of the great commercial nations in
filling their vital needs. Mexican graphite is the chief supply of good
material for pencils. Interest centers in the material capable of being
made into crucibles.
Crucible graphite has been produced in the past mostly in _Ceylon_. Its
granular form (characteristic of vein graphite) has been assumed by
crucible makers to be the best. The deposits are worked mostly by small
local owners in Ceylon, and the output is controlled by the British
through state sovereignty and shipping. Control by ownership and
operation with modern plant was attempted by an English company, but
met native opposition until a few years ago.
Recently _Madagascar_ flake graphite has largely replaced Ceylon
material in European practice. This deposit is under French sovereignty
and the French exercise a large degree of commercial control. The flake
graphite of the United States has not yet reached a high development.
There are large reserves of schist with about 5 per cent. graphite.
Bavarian material is crystalline though not of such good quality. It is
under German control. Prior to the war, mining and milling methods were
primitive, and the product correspondingly poor. _Canada_, _Norway_,
_Sweden_, _Greenland_, _Brazil_ and possibly others have reserves of
flake within their boundaries. _Japan_ has a small production of flake
graphite and controls a supply in Chosen.
American control of _Mexican_ mines brings the entire Mexican output to
this country for refining and re-export. One of the large _Canadian_
mines is also owned in the United States.
When the British supply in Ceylon declined and the Madagascar
production increased, the British, who had always controlled the
world’s main supply, did not readily relinquish control. They bought a
large part of the Madagascar product and have a concentrating plant on
the island. The Morgan Crucible Co., of London, operates on the island
as the French company “Graphites Maskar,” but this is a subsidiary of
the London company and the control is entirely British. This is not the
only plant, however, working on the island. One large company before
the war had its main office in Hamburg, Germany, one at Antwerp, and
there were several French companies. Some Austrian mines were owned by
Belgian companies prior to the war, and English interests own a part of
the Italian deposits.
During the war the French and British, having adopted the Madagascar
graphite successfully, apparently arranged an agreement by which that
supply should be used in Europe, while Ceylon graphite was sent mostly
to the United States. The control was only possible by a combination
of British and French, apparently a commercial rather than a political
matter, though subject to government control.
There appears to be a combination among Madagascar graphite producers,
as evidenced by a statement from the consul in Tananarive in November,
1918, that the “Union des Producteurs de Graphite” could furnish to
this country annually 15,000-20,000 tons of 85 per cent. graphite at a
definite price, f.o.b. Tamatave. The object of the combine appears to
be to protect producers against unfair practices of the manufacturer.
The Colombo Graphite Union is mentioned in some sources as a local
combination, probably interrelated with the Ceylon Chamber of Commerce.
It has not been active in improving mining and milling methods, and has
also objected to modernization by outside capital.
The Graphite Producers’ Association of Alabama was organized in
1917 and had for its objects the furthering of the interests of the
graphite miners of the state. An effort was made to sample and analyze
shipments honestly and thus help remove the most serious objections
that manufacturers had against using domestic flake--unreliability of
product.
POSITION OF THE NATIONS
Low-grade amorphous graphite is abundant in the _United States_.
There are supplies in many states and in Alaska, which have not been
developed to any extent. An excellent grade of material from Mexico
is available in large amounts, making extensive domestic development
unprofitable, except when the deposits are very favorably situated. The
most productive Mexican deposit is owned by the United States Graphite
Co., of Saginaw, Mich. Artificial graphite is made at Niagara Falls
in large amounts, making the country independent in the matter of
electrodes.
This country is not yet independent in the matter of crucible graphite.
Crucible makers have insisted on having Ceylon graphite, about 15,000
tons or more a year. The only supply of similar graphite in the country
is a very small deposit in Montana. However, there is a fair supply of
flake graphite in Alabama, Pennsylvania, New York, Alaska, Texas and
possibly other states. Some 3,500 tons a year were produced prior to
1919. This resembles Madagascar rather than Ceylon graphite, though
the flakes are smaller. American crucible makers are slow to make use
of it, though there is evidence that it might serve very well. If the
demand for crucible graphite continues, the demand for imports will
probably continue.
Our deposits are not so high grade or so favorably situated as to
compete successfully with those of Ceylon and Madagascar.
Canadian companies producing flake similar to that in the United States
are in part owned by United States capital.
The flake graphite supply for crucible makers in normal times may come
from Madagascar, but we can be fairly independent in case of necessity
if we are prepared to stimulate mining in this country.
_England_ controls the graphite from Ceylon. However, there seems to be
a general opinion that Ceylon production is likely to decrease unless
the control passes into the hands of some one who will introduce modern
efficient mining methods. England normally allows about two-thirds of
the Ceylon product to come to the United States. England’s own supply
of crucible graphite is now mainly obtained from Madagascar, where an
English owned and controlled company operates on the island. Amorphous
graphite is obtained from Italy and Chosen. A London company operates
in Quebec, producing some flake and dust. English capital is invested
in Italian graphite deposits and apparently also in the Spanish.
Through her sovereignty over Madagascar, _France_ probably controls
the world’s best future supplies of flake graphite. The deposits are
large, conveniently situated, and remarkably rich--20 per cent. or more
graphite. They are capable of greatly increased production. Already
the output exceeds that of any other country, though the deposits have
been developed but recently. France has a small local production of
amorphous graphite, and obtains some from Italy.
_Germany_ is now chiefly dependent on Bavarian flake graphite for
crucibles. The efforts made during the war to get Ceylon graphite in
through Holland and Switzerland indicate that the Bavarian supply is
not wholly satisfactory. Amorphous graphite is supplied from Austria.
Overproduction has made it possible at times to sell the products in
America below cost.
_Japan_ produces some flake graphite. Chosen has an abundant supply of
the amorphous variety. In Chosen there have been recent discoveries of
crystalline graphite which may be of importance.
Figure 11 shows the changes in the annual output of graphite in the
chief producing countries, and Figure 12 shows the percentage of
crucible graphites produced by the main sources of supply.
SUMMARY
Graphite occurs in nature in two forms, crystalline and amorphous, each
form having its own peculiar uses. Crystalline graphite is used in the
manufacture of crucibles, as a lubricant, and in paints. Amorphous
graphite is used as a lubricant, for foundry facings, in pencils,
in paints, as a polish for high explosives, in boiler compounds, in
electrodes, in dry batteries, as a stove and shoe polish, and as a
filler for fertilizers. Most of the above uses are essential and
cannot easily be eliminated. Artificial graphite made from coal or
other carbonaceous matter can be substituted for the natural amorphous
graphite.
[Illustration: FIG. 11.--Annual output of graphite in chief producing
countries, 1902-18. Full lines indicate crystalline graphite; dotted
lines principally amorphous graphite.]
[Illustration: FIG. 12.--Percentage of crucible graphite produced by
main sources of supply, 1907-1917. Bavarian data since 1913 doubtful,
but since completion of the graph it has been found that the 1917
production was much larger than shown.]
Amorphous graphite may occur wherever coal or other carbonaceous beds
have undergone regional or igneous metamorphism. Crystalline graphite,
both flake and vein, is usually found in association with granitic
intrusives. Since such rocks have not been thoroughly prospected in
all parts of the world, it is probable that important new deposits of
graphite will be discovered, especially in Canada, Siberia and parts of
South America and Africa.
Ceylon is the chief source of supply of the best grades of crystalline
graphite, viz., vein graphite. The crystalline graphite obtained in
Madagascar, Bavaria, and in small quantities in the United States,
Canada, Norway, Sweden, Japan and Chosen is chiefly of the flake
variety and for that reason it is considered by manufacturers inferior
in grade to that obtained in Ceylon. Large undeveloped deposits are
reported in Greenland and Brazil. The discovery of the large deposits
of flake graphite in Roumania was reported some time since. From
time to time discoveries are reported from other localities but the
importance is questionable, chiefly because the deposits are usually
situated in places difficult to reach. It is believed that the Ceylon
deposits have passed the maximum of their production and if deposits
of vein graphite of equal grade and richness could be found, Ceylon
producers might be hard pressed. During the last few years Madagascar
has become the leading producer of crystalline graphite, and the
influence of this potential supply should exert a stabilizing effect on
prices of Ceylon graphite.
Austria, Chosen, Mexico, Italy and the United States are the principal
producers of amorphous graphite; Chosen and Mexico supply most of the
pencil graphite of the world.
The development of the electric furnace will no doubt decrease the
demand for crucibles in steel making.
Great Britain, through sovereignty over Ceylon and Canada, and France,
through sovereignty over Madagascar, control politically the world’s
most important deposits of crystalline graphite. Japan controls the
deposits of Chosen.
American capital controls the deposits of the United States, the
deposits of Mexico, and in part the deposits of Canada. The Ceylon
deposits have been worked mainly by small local owners, who opposed
until a few years ago the attempts of an English company to gain
control through the erection and operation of a modern plant. The
Graphites Maskar, owning a part of the Madagascar deposits, is a
subsidiary of a British company, the Morgan Crucible Co. Another large
Madagascar company before the war had its main office in Hamburg,
Germany. Other companies are controlled by Belgian and French capital.
British interests own a part of the Italian and probably a part of the
Spanish deposits.