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phuric acid and sulphur trioxide, materials that are practically indispensable to the makers of high explosives and aniline colors. It is not possible to estimate the quantity of platinum tied up in the manufacture of sulphur trioxide, but the loss of platinum in the industry undoubtedly is very small. Should the price of platinum prohibit its use, sulphuric acid manufacturers could still make the fuming acid by substituting iron oxide for platinum.

In former years platinum was considered essential in electrical work where it is now replaced by “nichrome” and other alloys or metallic molybdenum and tungsten. In dental work, platinum plating gives as satisfactory results as the pure platinum formerly much used.

Probably our greatest economic waste of platinum at present is its increasing use as a setting for precious stones, but platinum settings may go out of style at any time and the platinum come back into the market. A large quantity of platinum is also tied up in the form of utensils in the various chemical laboratories throughout the United States.

Our domestic supply of platinum is entirely inadequate to meet present uses, but if these uses were cut to the essentials, it is believed that the United States could be independent of the world for some time. The western placer miners are realizing the practicability of saving the platinum as well as the gold, and new devices on gold dredges are saving much more of the platinum than those used heretofore. Further improvements seem likely.

The waste of such a valuable metal as platinum is very small, once the metal is on the market. It may be overlooked in placer mining, but in metallurgy it is not, as is shown by the large recoveries made by gold and copper refiners. The amount of scrap platinum handled during 1914, amounting to 40,500 ounces—more than 16 times our domestic production-shows the economy practiced in the use of this metal. Sweepings from jewelry manufacturing and dental establishments and scraps from every conceivable source that might contain platinum are refined and the metal recovered.

At the present time the United States Geological Survey and the Federal Bureau of Mines are cooperating in a general study of the placer deposits of the United States. This study is giving new information as to the places where platinum occurs and the best methods for its recovery.

QUICKSILVER (MERCURY).

The annual production of quicksilver in the United States is approximately 20,000 flasks of 75 pounds each, a total of 1,500,000 pounds, representing a total value of $800,000. During 1914 the

United States imported 615,000 pounds, largely from Italy, Austria, and England. The exports amounted to 108,000 pounds, mostly to South America, Canada, and France.

The chief producing districts in the United States are in California, that State yielding over two-thirds of the entire output. Texas, Nevada, and Arizona are small producers. Quicksilver is also found in Alaska, Washington, Oregon, and Utah, but many of these deposits have not been thoroughly prospected and developed.

The principal uses of quicksilver are in the manufacture of fulminate, in making electric appliances and in the milling of gold and silver ores. The quantity of quicksilver used for the latter purpose is much less than formerly because of the growing use of the cyanide process. Consequently more quicksilver is available for use in the manufacture of explosive caps and electrical appliances. More than 30 per cent of the gold mined in the United States is recovered by cyanidation, and only about 21 per cent by amalgamation, the total amount of quicksilver used for the purpose amounting to only 700 or 800 flasks a year.

The United States supply of quicksilver is ample for domestic use under normal conditions, and the increased use of wet processes for the extraction of gold leaves still more of the original supply available for other purposes.

BASE METALS.

IRON ORE AND PIG IRON.

In 1880 about 7,000,000 long tons of iron ore, valued at $17,500,000, were mined in the United States, as compared with 60,000,000 tons in 1913, valued at about $130,000,000. The production of pig iron increased in the same period from less than 4,000,000 tons to more than 30,000,000 tons, the value of which in 1913 exceeded $458,000,000. The United States leads the world in the production of these commodities, iron ore and pig iron, and produces annually about 40 per cent of the world's supply of iron. This is shown graphically in fig. 2.

Comparatively little iron ore is imported into the United States less than one-half of 1 per cent of the quantity annually mined. Moreover, the exports of iron ore from the United States nearly offset the imports, so that the United States is self-sufficient so far as the production of iron ore is concerned. Such ore as is imported comes mainly from Cuba, Sweden, Newfoundland, Canada, Spain, and Chile. It is possible to import high-grade iron ores, such as are received from the above countries, for use along the Atlantic seaboard when ocean freights are low and there is no tariff on the ore. Even under these favorable conditions, however, foreign ore rarely gets beyond the tidewater furnaces.

The United States is abundantly supplied with iron ore, yet there are excellent arguments in favor of encouraging imports of ore from Cuba and South America. Iron ore forms the basis of the largest manufacturing industry in the United States. The profits to both labor and capital are made from the manufacture and sale of iron and steel products rather than from iron ore mining, therefore, so long as the United States can utilize the cheap ores from Latin America and export to those countries as well as to Europe the fabricated iron and steel goods, there is reason to favor the continuance of these conditions. Moreover, since there is little good coal near the largest deposits of iron ore in South America it may never be feasible to establish the manufacture of iron there. The iron ore of that continent will find a market either in Europe or in the

TONS 30,966,152

19,004,022

10,481,917

3,227,378 4,474,757 2,335,10 2,318,767 1,015,118 2,203,588

FIG. 2.-World's production of pig iron in 1913.

United States, therefore, whatever is commercially available to the United States should serve a double purpose if sold here, viz., in increasing trade between the United States and South America and in conserving the ore supplies of the United States.

So far as exports of either iron ore or pig iron from the United States are concerned there is little reason for their encouragement.

Twenty-eight States are regular producers of iron ore and several others contain deposits of potential value.

The States in which iron ore occur may be conveniently grouped into six geographic divisions, namely:

1. Northeastern States.Massachusetts, Connecticut, New York, New Jersey, Pennsylvania, and Ohio.

2. Southeastern States.—Maryland, the Virginias, Kentucky, Tennessee, North Carolina, Georgia, and Alabama.

3. Lake Superior States.-Michigan, Wisconsin, and Minnesota.

4. Mississippi Valley States.-Iowa, Mississippi, Missouri, Arkansas, and Texas.

5. Rocky Mountain States.-Idaho, Montana, Wyoming, Colorado, New Mexico, Utah, and Nevada.

6. Pacific Slope States.-Washington and California.

The Lake Superior division is by far the most important, and it is followed in order by the southeastern division and the northeastern division. The Mississippi Valley and the western divisions are at present of minor importance, although it is certain that at no distant date California and Utah are destined to become large producers of iron ore.

Recent estimates credit the United States with about 7,500 million tons of iron ore of present-day commercial grade, of which about one-third is in the Lake Superior district. The rest of North America, including Newfoundland, Canada, Mexico, and Cuba, is credited with about 7,000 million tons. South America is credited with about 8,000 million tons, and may have more, and Europe with about 12,000 million tons, making a total of almost 35 billion tons of iron ore now known to exist on three continents bordering the Atlantic Ocean. It thus appears that the United States possesses more than one-fifth of this available supply.

Immense as this available supply may seem at first glance it is not sufficient to prolong production for many decades at the rate of increase in consumption of ore that has obtained thus far. The draft on the ore reserves of the Lake Superior district is relatively much heavier than on those of the other districts on account of the possibility of open-pit mining on the Mesabi Range. The Lake district now produces about four-fifths of the iron ore mined in the United States and it has been estimated that if this proportion is maintained the known ore reserves of present commercial grade in the United States portion of the Lake Superior district can not last much beyond the year 1930. Happily, however, there are factors, that, if taken into consideration, indicate the possibility of a considerable prolongation of the life of the Lake Superior iron-ore supplies and of the whole United States, for that matter.

The important factors bearing on the prolongation of the life of iron-ore reserves of the United States may be summarized as follows:

1. The steady accretion to the permanent supply of metal and the consequent reduction in rate of increase of production.

2. Methods of conservation of ore and metal.

3. Imports of ore from Cuba and South America, which must logically be regarded as a portion of the immediately available reserve, since such ores can be used most profitably and economically in the United States.

4. New discoveries of ore deposits.

5. As the price of pig iron increases, lower grades of iron ore will become suitable for use, thus vastly increasing the tonnage of reserves available.

6. Possibility of metallurgical improvements which will enable pig iron to be derived economically from low-grade ores.

7. The utilization of titaniferous iron ores, of which there are large deposits not now available by reason of the metallurgical problems involved.

Interest in this problem has already been awakened. Publications of this department containing estimates of iron-ore reserves based upon geologic field work show that, while relatively great, the reserves are actually limited, and statistical canvasses extending back for many decades also show the phenomenal increases in consumption of ore, so that data are available from which calculations have been made with reference to the life of the deposits.

Bureaus of the Interior Department may further the work of ironore conservation still more. Studies should be made bearing upon the decrease of wastage in iron-ore mining, and especially upon the problems of beneficiating iron ore, processes by which enormous supplies of ore of grade too low to be utilized under present conditions, may be made available. Here also is an opportunity for the invention of metallurgic processes by which pig iron may be made commercially from ores of lower grade than at present used, and ores may be smelted electrically in regions where cheap water power is available but good coal is scarce.

It is of interest to note that the discovery of iron ore in the Lake Superior district was made by a United States surveying party in 1844 on what is now the Marquette Range, near the site of the present town of Negaunee, Mich., and that the area of known deposits of iron ore has been greatly extended in this region through geologic surveys conducted by this department.

COPPER.

The production of copper in the United States has increased more than twenty-five fold since 1880. The production in 1913 was 1,652,000,000 pounds, valued at $255,500,000, as compared with a production of 60,480,000 pounds, valued at $12,000,000 in 1880. The world's production of copper is approximately 2,211,000,000 pounds, of which the United States produces 60 per cent, Europe 13 per cent, Canada and Mexico 8 per cent, South America and Cuba 7 per cent, and all other countries 12 per cent.

In 1913 the United States consumed about 41 per cent of the world's output of copper, or about 65 per cent of her production

8161°-INT 1915-VOL 1-11

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