Word Finder - manganese

definition

A metallic chemical element (symbol Mn) with an atomic number of 25, not a free element in nature but often found in minerals in combination with iron, and useful in industrial alloy production.

definition

A single atom of this element.

Iron, coal, copper and manganese are mined.

Manganese ore is mined for export, and bismuth is reported to have been discovered.

Recent experiments lead to the conclusion that iron, lead, manganese, lignite and sulphur exist in considerable abundance.

The chief minerals are sulphur, in the production of which Italy holds one of the first places, iron, zinc, lead; these, and, to a smaller extent, copper of an inferior quality, manganese and antimony, are successfully mined.

The colour of amethyst is usually attributed to the presence of manganese, but as it is capable of being much altered and even discharged by heat it has been referred by some authorities to an organic source.

The next group precipitate may contain the white gelatinous aluminium hydroxide, the greenish chromium hydroxide, reddish ferric hydroxide, and possibly zinc and manganese hydroxides.

The next group may contain black nickel and cobalt sulphides, flesh-coloured manganese sulphide, and white zinc sulphide.

A white precipitate rapidly turning brown indicates manganese.

The ore generally occurs in the form of oxides, manganite and pyrolusite, and contains a high percentage of sesquioxide of manganese.

Wolfram (tungstate of iron and manganese) occurs in some of the states, notably in New South Wales, Victoria, Tasmania and Queensland.

The manganese ores of the Bathurst district of New South Wales often contain a small percentage of cobalt - sufficient, indeed, to warrant further attempts to work them.

Gay-Lussac in 181q, is usually obtained in the form of its barium salt by suspending freshly precipitated hydrated manganese dioxide in water and passing sulphur dioxide into the mixture until all is dissolved; the barium salt is then precipitated by the careful addition of barium hydroxide.

The export that comes next in value is silk, and after it may be named wheat, barley, manganese ore, maize, wool, oilcake, carpets, rye, oats, liquorice and timber.

Now, however, the mottled soaps, blue and grey, are produced by working colouring matter, ultramarine for blue, and manganese dioxide for grey, into the soap in the frame, and mottling is very far from being a certificate of excellence of quality.

To the filtrate from the aluminium, iron and chromium precipitate, ammonia and ammonium sulphide are added; the precipitate may contain nickel, cobalt, zinc and manganese sulphides.

Lead and manganese are partially separated as peroxides, but the remaining metals are not deposited from acid solutions.

Lead chromate is sometimes used, and many other substances, such as platinum, manganese dioxide, &c., have been suggested.

Minerals, in which Oberhessen is much richer than the two other provinces, include iron, manganese, salt and some coal.

The mineral wealth of the Cyclades has hitherto been much neglected; iron ore is exported from Seriphos, manganese and sulphur from Melos, and volcanic cement (pozzolana) from Santorin.

Schefferite, or manganese pyroxene, is a brown mineral found in the manganese mines of Sweden.

Large copper deposits of peculiar richness occur here in the Sierra de Cobre, near the city of Santiago; and both iron and manganese are abundant.

Manganese occurs especially along the coast between Santiago and Manzanillo; the best ores run above 50%.

Iron and manganese have, on the contrary, been greatly developed in the same period.

Manganese is mined mainly near La Maya and El Cristo in Oriente.

Bosnia is rich in minerals, including coal, iron, copper, chrome, manganese, cinnabar, zinc and mercury, besides marble and much excellent building stone.

The mineral wealth of the department is considerable, including coal as well as manganese and bituminous schist; plaster, building stone and hydraulic lime are also produced.

They are silicates, usually orthosilicates, of aluminium together with alkalis (potassium, sodium, lithium, rarely rubidium and caesium), basic hydrogen, and, in some species magnesium, ferrous and ferric iron, rarely chromium, manganese and barium.

It oxidizes a manganese salt (free from chlorine) in the presence of nitric acid to a permanganate; this is a very delicate test for manganese.

Heusler that an alloy consisting of copper, aluminium and manganese (Heusler's alloy), possesses magnetic qualities comparable with those of iron.

The most striking phenomenon which they bring into prominence is the effect of any considerable quantity of manganese in annihilating the magnetic property of iron.

A sample of Hadfield's manufacture, containing 1 2.36% of manganese, differed hardly at all from a non-magnetic substance, its permeability being only 1.27.

The addition of 15.2% of manganese produced an enormous effect C.R., 1897, 124, 176 and 1515; 1897, 125, 235; 1898, 126, 738.2 Ibid., 1898, 126, 741.

Heusler 2 in 1903 that certain alloys of the non-magnetic metal manganese with other non-magnetic substances were strongly magnetizable, their susceptibility being in some cases equal to that of cast iron.

The metals used in different combinations included tin, aluminium, arsenic, antimony, bismuth and boron; each of these, when united in certain proportions with manganese, together with a larger quantity of copper (which appears to serve merely as a menstruum), constituted a magnetizable alloy.

So far, the best results have been attained with aluminium, and the permeability was greatest when the percentages of manganese and aluminium were approximately proportional to the atomic weights of the two metals.

Thus in an alloy containing 26.5% of manganese and 14.6% of aluminium, the rest being copper, the induction for H= 20 was 4500, and for H=150, 5550.

When the proportion of aluminium to manganese was made a little greater or smaller, the permeability was diminished.

In all such magnetizable alloys the presence of manganese appears to be essential, and there can be little doubt that the magnetic quality of the mixtures is derived solely from this component.

Manganese, though belonging (with chromium) to the iron group of metals, is commonly classed as a paramagnetic, its susceptibility being very small in comparison with that of the recognized ferromagnetics; but it is remarkable that its atomic susceptibility in solutions of its salts is even greater than that of iron.

Now iron, nickel and cobalt all lose their magnetic quality when heated above certain critical temperatures which vary greatly for the three metals, and it was suspected by Faraday 3 as early as 1845 that manganese might really be a ferromagnetic metal having a critical temperature much below the ordinary temperature of the air.

Guillaume 6 explains the ferromagnetism of Heusler's alloy by supposing that the naturally low critical temperature of the manganese contained in it is greatly raised by the admixture of another appropriate metal, such as aluminium or tin; thus the alloy as a whole becomes magnetizable at the ordinary temperature.

On the other hand, its susceptibility is about fifty times less than that of Hadfield's 12% manganese steel, which is commonly spoken of as non-magnetizable.

The exports cover a wide range of agricultural, pastoral and natural productions, including coffee, rubber, sugar, cotton, cocoa, Brazil nuts, mate (Paraguay tea), hides, skins, fruits, gold, diamonds, manganese ore, cabinet woods and medicinal leaves, roots and resins.

Among the minerals are silver, platinum, copper, iron, lead, manganese, chromium, quicksilver, bismuth, arsenic and antimony, of which only iron and manganese have been regularly mined.

Manganese is mined in Minas Geraes for export.

Mines of iron, manganese, and especially of mispickel, are worked, and there are stone-quarries and productive saltmarshes.

Of the impurities of the ore the wolframite (tungstate of iron and manganese) is the most troublesome, because on account of its high specific gravity it cannot be washed away as gangue.

Other metals, such as manganese, copper, nickel, may show their presence by characteristic colours.

The purple-blue of cobalt, the chrome green or yellow of chromium, the dichroic canarycolour of uranium and the violet of manganese, are constant.

Oxidation may be effected by the addition to the glass mixture of a substance which gives up oxygen at a high temperature, such as manganese dioxide or arsenic trioxide.