Iron is mainly mined in Elba.
Manganese is mined in Minas Geraes for export.
The iron ores mined at Daiquiri near Santiago are mainly rich hematites running above 60% of iron, with very little sulphur or phosphorus admixture.
Silver is not mined by itself, but is found in combination with gold.
They are important ores of silver (the pure chloride contains 75.3% of silver), and have been extensively mined at several places in Chile, also in Mexico, and at Broken Hill in New South Wales.
Manganese is mined mainly near La Maya and El Cristo in Oriente.
Salt has been mined there since the 16th century.
When these first four galleries were full others were mined on the same level at right angles to them, thus gradually converting the whole area into a net-work of corridors.
Copper is known to exist in all the states, and has been mined extensively in South Australia, New South Wales, Queensland and.
Peary and Astrup, as already indicated, crossed in 1892 the northern part of the inland ice between 78° and 82° N., o reaching a height of about 8000 ft., and deter mined the northern termination of the icecovering.
The quality of ore in the two ranges differs somewhat, that mined from the Vermilion Range being a hard specular or red haematite, while that taken from the Mesabi Range, largely red haematite, is much softer and in many localities quite finely comminuted.
Copper is mined and extensive deposits of petroleum and asphalt are being exploited.
The mica mined in India is practically all muscovite.
Anglesite, or lead sulphate, PbSO 4, is poor in silver, and is only exceptionally mined by itself; it occurs in quantity in France, Spain, Sardinia and Australia.
Several floors can be mined simultaneously, the work in the lower floors being kept well in advance.
Lignite is also mined at Bacu Abis, near Gonnesa, and Anthracite in small quantities near Seui.
The Flemish coal-basin, employing over 100,000 hands, produces 60% of the coal mined in France.
Gothite occurs with other iron oxides, especially limonite and hematite, and when found in sufficient quantity is mined with these as an ore of iron.
As quarried or mined free sulphur is always contaminated with limestone, gypsum, clay, &c.; the principle underlying its extraction from these impurities is one of simple liquation, i.e.
Gold has been mined in the Urals since 1820; but since 1892 the output has fallen off very considerably.
Portion of the Mountain Region; and that mica was mined here before any European settlement of the country seems proved by numerous excavations and by huge heaps on which are large oak and chestnut trees, some fallen and decayed.
Manganese ore is mined for export, and bismuth is reported to have been discovered.
Florida is also the principal source in the United States for fuller's earth, a deposit of which, near Quincy, was first discovered in 1893 and clay (including kaolin) is also mined to some extent.
Bituminous coal of an inferior quality is mined to a limited extent in Rio Grande do Sul, and another mine has been opened in Santa Catharina.
It is the shipping place for the iron ore mined at Gellivara, 127 m.
Gold and silver are chiefly found in Transylvania, where their exploitation dates back to the Roman period, and are mined at Zalatna and Abrudbanya; rich deposits are also found in the Kremnitz-Schemnitz, and the Nagybanya districts.
Coal is extensively mined in the region of Budapest-Oravicza, Nagybanya, Zalatna, at Brennberg near Sopron, at Salgo-Tarjan, Pecs, in the counties of Krasso-Szoreny, and of Esztergom, and in the valley of the river Zsil.
Mieres is the chief town of a mountainous, fertile and well-wooded region in which coal, iron, and copper are extensively mined and sulphur and cinnabar are obtained in smaller quantities.
The minerals chiefly mined besides gold are diamonds and coal, but the country possesses also silver, iron, copper, lead, cobalt, sulphur, saltpetre and many other mineral deposits.
The Rand reefs, first mined in 1886, cover a large area.
Lode tin, as tinstone derived from primary deposits is often termed, is mined in the ordinary method, the very hard gangue in which it occurs necessitating a liberal use of explosives.
Sulphur is mined near Carupano, and salt in Zulia and on the peninsula of Araya.
Anthracite is mined in the St Lucia Bay district, and bituminous coal is found in the Nqutu and Kyudeni hills.
It is not desirable to leave large areas standing upon pillars in the mine, and as soon as the work on any level is completed the pillar below should be mined out as far as is safe, and the abandoned portion of the mine allowed to cave in and lessen the weight on the pillars elsewhere.
In this case the advanced drift is run underneath the pillar, and the ground below is mined in descending steps.
This method has the advantage of permitting the ore to be sent to the surface as fast as it is mined instead of being left for some months in the stopes for the men to stand upon.
The ore as mined is hand-picked and the barren material allowed to remain in the stope where it falls.
These separate areas are then mined in small rooms, each room being timbered as in mining under a weak roof rock.
The floor containing these old haulage roads now becomes the top slice of the one hundred-foot block of ground below and is mined out as described.
Several floors may be mined simultaneously, FIG.
Backof ore above are then mined in retreating back towards the haulage road.
Instead of mining in horizontal floors the filling method permits the ore to be mined in vertical chambers or slices which extend from one level to the next above and from one wall of the deposit to the other.
When a chamber has been excavated and completely filled the slice adjoining is mined out, or at times a block of ground may be left untouched between two filled chambers and then mined out.
The ore is mined in the ordinary way, by pick and shovel if soft, or by the aid of powder if necessary, and the funnel-shaped bottom of the pit is maintained at such an angle that little or no shovelling is required to bring the excavated material to the shaft.
For the special methods by which placer deposits are mined see Gold.
R000 tons; and as the mineral is mined the weight on the pillars left will be proportionately greater.
The material as mined will probably not average over 10 per cent.
The church of St John the Baptist, principally Perpendicular, - has in its tower three bells presented by Charles Both this town and the adjacent urban district of Radstock (pop. 3355) have a considerable trade in coal, which is mined in the vicinity.
Coal is mined in the neighbourhood.
Coal is mined in the vicinity; the city has a large trade with the surrounding agricultural district (whose distinctive product is beans); the Michigan Central railway has car and machine shops here; and the city has many manufacturing establishments.
This was a conservative estimate, and was made before the full extent of the reefs was known; in 1904 Lionel Phillips stated that the main reef series had been proved for 61 m., and he estimated the gold remaining to be mined to be worth £2,500,000,000.
Grain and fruit are grown in large quantities, and much coal is mined in the vicinity of Kirksville.
The town has trade in grain, iron, mined in the vicinity, and leather.
Lead and zinc are mined in much smaller quantities, alum and sulphur are also.
Those of economic value are kaolin, mined chiefly in the vicinity of Hockessin, New Castle county, the static kaolin product being exceeded in 1903 only by that of Pennsylvania among the states of the United States; granite, used for road-making and rough construction work, found near Wilmington; and brick and tile clays; but the value of their total product in 1902 was less than $500,000.
These are little mined at present, only 110 tons of lead ore and 516 tons of zinc ore being taken from the mines in 1908.
Mica is mined near Mrogoro.
It is abundant, for example, in the plastic clay of the Brown Coal formation at Littmitz, near Carlsbad, in Bohemia, at which place it has been extensively mined for the manufacture of sulphur and ferrous sulphate.
Copper and mispickel are mined only in small quantities.
Bismuth is known to exist in all the Australian states, but up to the present time it has been mined for only in three states, viz.
A sub-bituminous lignite is mined in Esmeralda county (800 tons in 1906; 330 tons in 1907).
Rock-filling will be used whenever a large proportion of barren material must be mined with the ore.