MANGANESE ORE.

By ERNEST F. BURCHARD.

INTRODUCTION.

According to reports received by the United States Geological Survey, the manganese ore industry showed less activity in 1909 than in 1908. Manganese ore was mined in 1909 in California, Tennessee, and Virginia, but only in Virginia was the output of consequence. No production has been reported from South Carolina since 1907. The table of total production shows that only in three years, 1886, 1887, and 1888, has the production of manganese ore reached 25,000 tons annually and that during the last 10 years the industry has not been in a prosperous condition. In 1909 the quantity marketed amounted to 1,544 long tons, valued at $19,675, the price per ton averaging $12.74, as compared with 6,144 long tons, valued at $62,779, an average price per ton of $10.22, in 1908. In addition to the quantity shipped, a small tonnage was mined and remained in stock at the mines at the end of the year, but definite figures as to this stock are not available.

The greater part of the high-grade manganese ore mined in the United States is used in the manufacture of brick, glass, and chemicals. The importations of manganese ore greatly exceed the quantities mined in this country-a condition likely to continue so long as the principal sources of foreign supply are large and cheaply worked, ocean freights are low, and there is no tariff on the ore.

The production of manganiferous ores, which include manganiferous iron ores and manganiferous silver ores, increased notably in 1909, the total quantity reported being 843,689 long tons, as compared with 523,034 tons in 1908. The manganiferous iron ores for the most part contained less than 6 per cent metallic manganese and were used in the production of a high-manganese pig iron. The manganiferous silver ores were mined in Western States in connection with lead, zinc, and precious metals. Part of this product was used in the manufacture of spiegeleisen, and part was used as flux in the copper and silver smelters.

The production of manganiferous zinc residuum from New Jersey zinc ores in 1909 amounted to 141,264 long tons, as compared with 110,225 tons in 1908. The production of this material has shown a gain every year since 1905, with the exception of 1907.

SOURCES OF MANGANESE.a

The principal manganese minerals forming ores of manganese are the following:

These minerals occurring separately or combined among themselves or with other minerals form four different classes of materials from which manganese is obtained commercially: (1) manganese ores, (2) manganiferous iron ores, (3) manganiferous silver ores, and (4) manganiferous zinc residuum. Manganese ores consist of various mixtures of manganese oxides, sometimes containing admixtures of manganese carbonate.

Manganese ore.-Deposits of manganese ore occur in many parts of the United States, but are most abundant in the Appalachian and Piedmont regions, in the southern Mississippi Valley, and on the Pacific coast. Small deposits occur in the New England, Rocky Mountain, and Great Basin regions. The principal producing districts up to the present have been the James River-Staunton River, and the Blue Ridge regions in Virginia; the Cave Spring and Cartersville districts in Georgia; the Batesville district in Arkansas; and the Livermore-Tesla district in California. Of minor importance are the New River region in Virginia, the northeastern Tennessee region, the McCormick region in South Carolina, and the Little Grande district in Utah. At present mining and shipping is confined to the Blue Ridge and James River-Staunton River regions in Virginia.

Manganiferous iron ores.-Manganiferous iron ores consist of mixtures of manganese and iron oxides. Manganiferous iron ores occur in the United States chiefly in the New England, the Appalachian, and the Lake Superior regions, and minor deposits are found in the southern Mississippi Valley and in the Rocky Mountain region. High-grade manganiferous iron ore used for its manganese content occurs in the Appalachian region. Other manganiferous iron ores are produced in the Appalachian and the Lake Superior districts which are so low in manganese that they are classed as iron ores. In the blast furnace they yield a "high-manganese" pig iron, which is used for special purposes.

Manganiferous silver ores.-Manganiferous silver ores consist of mixtures of manganese and iron oxides with small quantities of silver

a Notes by E. C. Harder, of the U. S. Geological Survey.

sulphide and lead carbonate. As a rule, the iron content exceeds the manganese content, but locally the iron is altogether absent.

Manganiferous silver ores are divided into three classes, according to their uses. (1) The greater portion of the manganiferous silver ores are used for their silver and lead content. Manganese and iron content often insures those ores a higher price because of their fluxing value. (2) A second class of manganiferous silver ore is too low in silver and lead to be used as a source for these metals, but is sufficiently high in manganese and iron to be used for the manufacture of ferromanganese and spiegeleisen, as is the case with the high-grade manganiferous iron ores already mentioned. (3) There is a third

class of manganiferous silver ore too low in silver and lead to be used primarily for these metals and too low in iron and manganese to be used for the manufacture of iron-manganese alloys. This ore is sold to the smelters as flux, the iron and manganese becoming waste products, while the silver and lead content is recovered during the smelting.

Manganiferous silver ores occur in the Rocky Mountain and Great Basin regions, the principal producing locality being Leadville, Colo. Some of the Leadville ores are used in the manufacture of spiegeleisen. All the other localities produce these ores for fluxing only.

Manganiferous zinc residuum.-Manganiferous zinc residuum is an artificial furnace product consisting of mixtures of manganese and iron oxides in a matrix of slag. Manganiferous zinc residuum is obtained from zinc volatilizing and oxidizing furnaces using New Jersey zinc ores. The residuum consists largely of iron and manganese oxides, the zinc having been removed by volatilization and collected as zinc oxide. The crude ores consist of franklinite, zincite, and willemite, and are obtained only from the Franklin Furnace district, New Jersey. Small quantities of zinc residuum are used annually in the manufacture of spiegeleisen.

USES OF MANGANESE. a

The principal use of manganese ores is in the manufacture of ironmanganese alloys such as spiegeleisen, ferromanganese, silverspiegel, and silicomanganese. The first two of these contain principally iron and manganese; the last two contain considerable silicon in addition. Ferromanganese and spiegeleisen are used in steel manufacture as reducers of iron oxide during the final melting, as recarburizers, and in the manufacture of special steels alone or in combination with chromium, nickel, tungsten, and other steel-hardening metals. Manganese is also used in the formation of alloys with copper, aluminum, zinc, tin, and other metals.

Manganese ores or manganiferous iron ores are used to a slight extent as fluxes in the reduction of silver, lead, and copper ores.

Manganese peroxide is used as an oxidizer in the manufacture of chlorine, bromine, and oxygen, and of potassium ferromanganate; as a drier in paints and varnishes; as a decolorizer of glass; and in the manufacture of the dry and the Leclanche cells. As a coloring material, manganese is used in coloring glass, bricks, and pottery. Several manganese salts are used in drying cloth and as paints.

a Notes by E. C. Harder of the U. S. Geological Survey.

More complete discussions of the sources, uses, and occurrence of manganese ores were published in the statistical reports on manganese ores for 1907 and 1908, and in a general report on manganese recently published by the Survey."

MANGANESE-ORE INDUSTRY.

PRODUCTION.

Manganese ore. The production of manganese ore in 1909 was 1,544 long tons, valued at $19,675, which was less than the production. of any single year heretofore recorded. The greater part of the production in 1909 was from Virginia, minor quantities being shipped from California and Tennessee.

The following table shows the quantity, value, and average price per ton of the manganese ore produced in the different States in 1907, 1908, and 1909:

Production of manganese ore in the United States, 1907-1909, by States, in long tons.

The following table shows the total production of manganese ore in the United States, by States, as compiled from previous volumes of Mineral Resources. The production prior to 1880 is only approximate, but probably did not exceed 50,000 long tons. The table shows Arkansas, Georgia, and Virginia as the principal producers, California as a fairly steady producer but only of small quantities, and the other States as producing small quantities of ore intermittently. The table also shows the periods of comparatively large production followed invariably by marked declines; but the present decline, which shows no indications of being followed by an immediate revival of production, is by far the most serious of all.

a Harder, E. C. Manganese ores: Mineral Resources U. S. for 1907, U. S. Geol. Survey, 1908; Mineral Resources U. S. for 1908, U. S. Geol. Survey, 1909.

b Harder, E. C. Manganese deposits of the United States, with sections on foreign deposits, chemistry and uses: Bull. U. S. Geol. Survey No. 427, 1910.