PRODUCTION OF IRON ORE BY VARIETIES, IN VARIOUS STATES AND MINING DISTRICTS.

Iron minerals are classified as sulphides, oxides, carbonates, silicates, etc., of which only the oxides and carbonates are used in the steel industry. The ores of iron are generally classed under four heads:

1. Hematite: Including all the anhydrous sesquioxides (Fe,O,—
theoretical percentage of iron, 70). This is known locally
as red hematite, specular ore, gray ore, fossil ore, oolitic
ore, etc.
2. Brown ore: Including hydrated sesquioxides, such as limonite,
göthite, and turgite (Fe,O,nH,O-theoretical percentage of
iron, 59.8-66). This is known locally as brown iron ore,
brown hematite, bog ore, limonite, etc.

3. Magnetite: Including magnetic oxides (Fe,O,-theoretical per-
centage of iron, 72.4). Magnetite is known generally as
magnetic iron ore.

4. Iron carbonate: Including carbonates of various types (FeCO,-theoretical percentage of iron, 48.2). Iron carbonate is known locally as spathic iron ore, kidney ore, black band ore, siderite, etc.

Hematite has always been predominant as an ore of iron, and at present constitutes almost nine-tenths of the iron ores produced. Brown ore and magnetite are far below it in importance, each furnishing at present about one-twentieth of the total iron-ore production. The production of iron carbonate is insignificant in comparison with that of the other ores, constituting only about one-twentieth of 1 per cent of the total.

In the following table are shown the quantities of each of the classes of iron ores produced in the various States during 1907 and 1908:

Production of iron ore in the United States in 1907 and 1908, by States and varieties, in long tons.

Production of iron ore in the United States in 1907 and 1908, by States and varieties, in long tons-Continued.

From this table it will be seen that the great bulk of the hematite comes from the Lake Superior district (Michigan, Minnesota, and Wisconsin) and Alabama, the brown ore from the Appalachian States, and the magnetite from New York, New Jersey, and Pennsylvania. All the iron carbonate is obtained from Ohio.

The following table shows the production of the different varieties of iron ores in the principal iron mining districts during 1908:

Production of iron ore in the United States, by mining districts and varieties, in 1908, in long tons.

The

In the following table is shown the production of the various types of iron ores in the United States as far as has been recorded. statistics from 1889 to the present were collected by the United States Geological Survey; those for 1860, 1870, and 1880 were collected for the census reports of those years; those for 1875 and 1881 were esti

mated by I. L. Bell,a and those from 1882 to 1888, inclusive, were estimated by James M. Swank from the pig-iron production. No figures can be obtained for the production of various classes of iron ores prior to 1889, except for the census year 1880.

Production of iron ore in the United States, 1860-1908, in long tons.

a Figures given are for consumption of domestic ores. Total production for 1882, 1883, and 1884 is estimated as 9,000,000, 8,400.000, and 8,200,000 tons, respectively. See Mineral Resources U. S. for 1883 and

1884.

In the following table the production of iron ores in the United States is shown from 1810 to 1869, and by decades from 1870 to 1908. The figures for the years previous to 1889 were calculated from the pig-iron production and include imported ore as well as domestic ore used.c

Production of iron ore in the United States from 1810 to 1908, by decades, estimated from pig-iron production.d

During 1908, of the 407 iron-ore mines in operation 150 produced over 50,000 long tons of iron ore each, as compared with 169 mines in 1907. The maximum production of any one mine was 2,926,614 tons from the Hull Rust, of the Mesabi range, Minnesota. Four

a Bell, I. L., Principles of the Manufacture of Iron and Steel, 1884, p. 451.

b Mineral Resources U. S., 1882 to 1888.

Hayes, C. W., Iron ores of the United States: Rept. National Conservation Commission, Sen. Doc. No. 676, 60th Cong., 1909. See also Bull. U. S. Geol. Survey No. 394, 1909, pp. 70-113.

d The figures, previous to 1889, include imported ores.

mines, all except one being located in Minnesota, produced 1,000,000 tons each. The exception was the Red Mountain group of the Birmingham district, Alabama.

Permission has been obtained from the owners and operators of 134 of these important mines to publish their production, and this information is given in the following table:

Iron-ore mines of the United States that produced more than 50,000 long tons each in 1908.

Iron-ore mines of the United States that produced more than 50,000 long tons each in 1908-Continued.

Includes the product of 16 mines producing over 50,000 long tons each, operated by eight companies, which object to the publication of individual statistics.