Chapter XXII: 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.

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.