Political and commercial geology and the world's mineral resources

by Unknown

From 98 to 99 per cent. of the United States production has come from the Gulf Coast region of the states of Louisiana and Texas. A number of other localities in West Texas, Colorado, Wyoming, Idaho, and Nevada have surface deposits, usually of limited extent, which have been worked on a small scale, but have declined in importance with the development of the better-grade and more accessible deposits of the Gulf Coastal region.

The occurrence of sulphur in the Gulf Coast region is in connection with a peculiar formation known as “Saline Domes” or “Mounds.” Over twenty of these domes have been located, scattered in an area 200 miles long, extending through western Louisiana and eastern Texas, and generally within 50 miles of the Gulf of Mexico. Commercial deposits of petroleum, sulphur, and salt have been developed in connection with these domes, but so far not more than one of the minerals has been developed to commercial degree in a single dome. Sulphur was discovered when drilling was being carried on for oil. So far, three domes have been developed for sulphur, namely that owned by the Union Sulphur Co. at Sulphur, La. (1903), that owned by the Freeport Sulphur Co. at Freeport, Texas (1912), and that of the Texas-Gulf Sulphur Co. near Matagordo, Texas (1919). Two other domes are under exploration and a number of others may possibly contain sulphur.

The sulphur occurs at a depth of 300 to 1,200 feet and is associated with limestone and underlain by gypsum. The surface area of the producing domes varies from 200 to 1,500 acres. Exploration is done by drilling at a cost of $200,000 to $300,000, and the cost of a complete plant is several million dollars. The sulphur cannot be mined by shafts, due to the quicksands and the poisonous gases encountered. The deposit at Sulphur, Louisiana, remained unworked for almost 40 years after its discovery before a satisfactory process was developed to mine it. This is known as the “Frasch Process” and consists of the sinking of wells to the sulphur deposit, each well being lined with a 10 to 12 in. pipe. Smaller pipes are placed inside, so that superheated water can be brought in contact with the sulphur ore, which is melted and forced to the surface by compressed air. The sulphur on cooling is ready for market and is over 99 per cent. pure. Each of the three plants in operation is equipped with a boiler capacity of over 20,000 h.p. for superheating the water, and requires about a million and a quarter barrels of fuel oil per year. The origin of these domes is believed to be due to deep-seated igneous intrusions, resulting in the alteration of gypsum and the crystallization of salt and sulphur, which has caused an upbowing of the strata. Because of the nature of the formation and the irregularity of the deposits it is impossible to accurately estimate the reserves of sulphur.

With the addition of two new plants since 1912, the United States now has a sulphur-producing capacity of about 1¹⁄₄ million tons per year, or four times the normal sales before the war. If an outlet is to be found for this excess sulphur, it must compete with pyrite in the domestic market or with Sicilian sulphur in the European markets. In the latter part of 1919 prices of $14 to $15 per ton f.o.b. mines were quoted, which indicated that an effort was being made to secure part of the acid trade which formerly used pyrite.

There is no element of political control in the United States sulphur industry, beyond the temporary measures taken during the war in licensing export and allocation of consumption. The commercial control is entirely in the hands of American companies. The Union Sulphur Co. has been endeavoring to prevent the use of the improved “Frasch Process” by the other companies which are competing with it. If the claim of infringement of patent rights should be sustained, it would give the Union company control of the situation similar to that which it had before the development of the two newer companies, and might result in the restriction of output and maintenance of prices.

Japan.

—Japan takes third rank in the production of sulphur, although it is of minor importance, compared to either the United States or Italy. The production of sulphur in Japan has slowly increased from 15,000 long tons in 1900 to 60,000 tons in 1913, or about 7 per cent. of the world output. The domestic consumption is very small and about 90 per cent. of the output was exported, chiefly to Australia, the west coast of the United States and Canada, and to China and India. During the war the output increased to a maximum of about 100,000 tons, but in 1918 production was considerably curtailed by the great advance in freight rates to Australia, which had been purchasing about one-half of the Japanese output.

The sulphur occurs in surface deposits of limited extent and seldom reaches 100 feet in thickness. The deposits are generally of the solfataric type and occur in the numerous areas of volcanic activity. The majority of the productive areas are nearly circular in outline, and indicate that they were formed by deposition in crater lakes. In some cases they are stratified and overlain by fine brown clayey or tufaceous material derived partly from the surrounding rocks and partly from the sulphur itself. Other deposits of minor importance may have been produced by impregnation. The ore mined runs from 50 to 60 per cent. sulphur. Deposits below 40 per cent. sulphur are seldom worked.

Approximately two-thirds of the production has come from the southwestern section of the Island of Hokkaido. Four mines average about 10,000 tons production each per year, and the remainder of the production comes from 10 to 12 smaller operations, ranging from the vicinity of Mount Daiton, in Taiwan (Formosa), to the Kurile Islands.

There is no accurate estimate of ore reserves available. One of the most important mines was estimated as containing several million tons of 50 per cent. ore. The reserves are probably sufficient to maintain present production for many years. The lack of shipping facilities has handicapped production, and there seems little likelihood that the relative importance of Japan in the sulphur industry will increase to any great extent.