Iron ore

“ As a commercial product, such as is used in the arts and manufactures and by the smith, it is always combined with other substances, such as carbon, silicon, and phosphorus.
Iron is distributed through the earth very widely, but not always in sufficient quantities to make its extraction from the ore profitable; consequently the ores used for the extraction of iron are somewhat limited. There are four general grades of iron ore, which are known by the following names: magnetite, red hematite, limonite, and ferrous carbonate. ”

“ CHAPTER XI. IRON—NICKEL—COBALT—ZINC—CADMIUM. IRON.
Iron rusts or oxidises very readily, and, consequently, is rarely found in the metallic state in nature; such native iron as is found being generally of meteoric origin or imbedded in basalt and other igneous rocks. It chiefly occurs as oxide, as in magnetite, hæmatite, and in the brown iron ores and ochres. Chalybite, which is carbonate of iron, is an ore of great importance. Iron is found combined with sulphur in pyrrhotine and pyrites, and together with arsenic in mispickel. ”

“ The end of all iron is the same. However many may be its metamorphoses while in the service of man it relapses at last into its original state of oxidation. To save a pound of iron from corrosion is then as much a benefit to the world as to produce another pound from the ore. In fact it is of much greater benefit, for it takes four pounds of coal to produce one pound of steel, so whenever a piece of iron is allowed to oxidize it means that four times as much coal must be oxidized in order to replace it. And the beds of coal will be exhausted before the beds of iron ore. ”

“ Reaumur, who about 1722 discovered the annealing process, used iron oxide for the purpose. The white iron was packed in iron ore or mill scale. At the high temperatures employed the oxygen of the ore in some way not yet definitely known, gradually removed the greater amount of the carbon from the casting. It has always been a scientific conundrum how a solid, iron oxide, surrounding another solid, a piece of white iron, could remove from the latter its carbon when neither of them melts nor mingles with the other. ”

“ Primitive furnace for smelting iron ore.
Not many of us have ever seen iron, the pure metal, soft, ductile and white like silver. As soon as it is exposed to the air it veils itself with a thin film of rust and becomes black and then red. For that reason there is practically no iron in the world except what man has made. It is rarer than gold, than diamonds; we find in the earth no nuggets or crystals of it the size of the fist as we find of these. But occasionally there fall down upon us out of the clear sky great chunks of it weighing tons. These meteorites are the mavericks of the universe. ”

“ In only a few localities is iron ore found in a metallic or "native" form. Many meteorites consist of metallic iron mixed with nickel and manganese, and in Greenland a volcanic dyke or ledge of metallic iron is known to exist. The iron of commerce is derived from "ores," or chemical compounds of iron and oxygen, or iron and carbon. The cheapness of the product depends upon the ease with [Pg 163] which the ore may be quarried, transported to coal, and smelted. ”

“ Considerable amounts of iron ore are also consumed annually for flux in the smelting of silver, copper, lead, and other metalliferous ores.
Iron and its products are more widely used than any other metal; and the yearly production of pig iron makes up 94 to 96 per cent. of the total amount of all the metals produced in the world, and in normal times averages about 80,000,000 tons annually. ”

“ Percentage of iron is of course an important factor; but an ore in which the iron is in the mineral hematite is more valuable than one with an equivalent percentage of iron which is in the form of magnetite. Substances present in the ore in minor quantities, such as phosphorus, sulphur, and titanium, have a tendency to make the iron product brittle, either when it is cold or when it is being made, so that excessive amounts of these substances may disqualify an ore. Excessive quantities of silica, lime, or magnesia may make the ore undesirable. ”

“ Instead of the 66 per cent iron ores of some years ago those coming nowadays contain not much more than 59 per cent of iron and the Bessemer ores described above are getting scarcer, so that for some years practically all of the furnaces have been mixing with them as much higher phosphorus ore as could be used without pushing the phosphorus content of the mixture over the allowable limit.
We often hear people surmising what is to become of us when all of the iron ore of this planet has been used. There is no harm in taking stock of resources and in this case it does us much good. ”

“ Iron we need, and iron we must have. We cannot well do without it, and have it we must, if we have to send to England for it. We have an abundance of the best quality of iron ore. A trial furnace was made, and kept hot for sixteen days, and produced as good pig metal as can be found in the world ”

“ Lead, iron, coal, gypsum, manganese, zinc, antimony, cobalt, ochre of various kinds, common salt, nitre, plumbago, porphyry, jasper, chalcedony, buhrstone, marble, and freestone, of various qualities. The lead and iron ore are literally exhaustless, and of the richest quality. To say there is probably iron ore enough in this region to supply the United States with iron for one hundred thousand years to come, would not be extravagant. Here, too, is water power in abundance, rapid streams, with pebbly beds, forests of timber, and exhaustless beds of bituminous coal. ”

“ In detail this group is represented by several mineral varieties, principal among which are hematite (Fe2O3) , magnetite (Fe3O4) , and limonite (hydrated ferric oxide) . Iron likewise combines with a considerable variety of substances other than oxygen; and some of these compounds, as for instance iron carbonate (siderite) , iron silicate (chamosite, glauconite, etc.) , and iron sulphide (pyrite) , are locally mined as iron ores. While an ore of iron may consist dominantly of some one of the iron minerals, in few cases does it consist exclusively of one mineral. ”

“ Prescott, “just remember three things: fuel, blast, and hammer—power, of course, behind the hammer. It’s the different variations that men have been making on those three things that have brought iron where it is to-day.
“Iron ore has so many things besides iron in it that the problem has always been how to get the impurities out.
“The old blacksmiths used to put it in the fire and hammer it; put it back in the fire and hammer again, until they worked most of the other things out. They made what is called forge iron. ”

“ The reduction of the ores of iron into metallic iron is in principle very simple, because when the oxides of iron are strongly heated with charcoal, hydrogen, carbonic oxide, and other reducing agents, [5] they easily give metallic iron. But the matter is rendered more [322] difficult by the fact that the iron does not melt at the heat developed by the combustion of the charcoal, and therefore it does not separate from those mechanically mixed impurities which are found in the iron ore. ”

“ Upon a close examination of the specimen that I had brought away with me in my bag, home to the Hermitage, and by consultation with my book, I felt convinced that I had discovered what is called magnetic iron; that is, iron ore that is most universally dispersed over the earth. The action of the compass added to this belief, and the limestone formation was exactly fitted to this kind of ore, which is the same as is generally called the Swedish iron ore, one of the best-known irons in the world. ”

“ Man was pretty well along on the road to civilization before he learned where iron could be found in beds, and how it could be purified for his use. We now know that certain very minute plants, which live in quiet water, cause iron brought into that water to be precipitated, and to accumulate in the bottom of these boggy pools. In ancient days these bog deposits of iron often alternated with coal layers. Millions of years have passed since these two useful substances were laid down. To-day the coal is dug, along with the bog iron. The coal is burned to melt the iron ore and prepare it for use. ”

“ Though iron is universally distributed throughout creation, it must occur in large beds or deposits before it can be profitably mined. “The most favorable situation of an iron ore for profitable extraction is near good coking coal for smelting and limestone for a flux, as in the Birmingham district of Alabama; and in such a situation even low-grade ores can be worked profitably. ”

“ It usually contains from 60 to 70 of metallic iron in 100 parts; the equivalent proportion of oxygen in the pure red oxide of iron being 30 parts combined with 70 of metal. It is a mistake to suppose any specular iron ore capable of yielding 85 per cent. of iron, for 100 parts of even protoxide of iron contain only 77·77 parts of metal.
The compact variety comprises the crystals of the island of Elba, and of Framont in the Vosges, which have a rough-grained fracture. It exists in very great masses, constituting even entire mountains ”

“ The iron ores of Great Britain include siderite, limonite, and hematite. The Cleveland district is the most important, and produces siderite averaging 30 to 40 per cent. in iron from deposits in the coal measures. Limonite is mined in Lincolnshire, Northamptonshire, and Leicestershire, and hematite in Lancashire and Cumberland. As the domestic supply of ore is insufficient, large quantities are imported from Spain, Sweden, Greece, and other countries. Germany has iron-mines in Alsace-Lorraine, Westphalia, and Hesse-Nassau, and the Grand Duchy of Luxemburg is noted for its iron. ”

“ The normal annual production of iron ore in Greece has been in the neighborhood of 400,000 tons.
Canada. —Small iron-ore deposits occur in New Brunswick and Nova Scotia. In Ontario there are two principal iron-ore districts—the Atikokan and the Michipicotan ranges. The ore in the former is magnetite, and in the latter hematite and siderite with some limonite. The ores of western British Columbia are largely magnetite. The principal deposits are on Texada and Vancouver islands, where the ore is of excellent grade, averaging 63 per cent. iron, 0.02 per cent. phosphorus and 4 to 10 per cent. ”

“ The output of iron ore has greatly increased; in 1870-1880 it averaged annually little more than one-quarter of the amount in 1902. The deposits of iron ore are confined almost wholly to the extreme north of Norrland, and to a midland zone extending from the south of the Gulf of Bothnia to a point north of Lake Vener, which includes the Dannemora ore fields in the eastern part. ”

“ Iron ores are widely distributed over the world, but are produced and smelted on a large scale only in a few places where there is a fortunate conjunction of high grades, large quantity, proximity of coal, cheap transportation to markets, and manufacturing enterprise. Over 90 per cent of the iron ore production of the world is in countries bordering the North Atlantic basin. The United States produces about 40 per cent, France about 12 per cent, England about 10 per cent, Germany before the war 15 to 20 per cent, and Spain, Russia, and Sweden each about 5 per cent. ”

“ But, intermediate in richness between these two extremes, the iron ores mined to-day and these 2 and 3% ores, there is an incalculably great quantity of ore capable of mechanical concentration, and another perhaps vaster store of ore which we do not yet know how to concentrate mechanically, so that the day when a pound of iron in the ore will cost as much as a pound of copper in the ore costs to-day is immeasurably distant. ”

“ Ibid.
"Red Oxide of Iron.—This occurs, though not very abundant, in the hills near Isle a Loutre, on the Missouri river. Its texture is compact, fracture earthy. Its external colour is brownish red; its streak and powder is blood red. This variety of ore produces good iron, and yields from sixty to eighty per cent." Ibid.
"Hematitic Brown Oxide of Iron.—This variety of iron ore occurs in considerable quantity in the vicinity of the vein of fluate of lime, near Shawaneetown, Illinois. ”

“ In short, a very large part of the earth’s coal supply is known and measured, but its iron ore supply is hardly to be guessed. On the other hand, the cost of iron ore is likely to rise much faster than that of the potential aluminium ores, clay and its derivatives, because of the vast extent and richness of the deposits of this latter class. It is possible that, at some remote day, aluminium, or one of its alloys, may become the great structural material, and iron be used chiefly for those objects for which it is especially fitted, such as magnets, springs and cutting tools. ”

“ They enter most often into the truer and more homogeneal substance of the globe, and in the process of time a vein of iron results; loadstone is also produced, which is nought else than a noble kind of iron ore: and for this reason, and on account of its substance being singular, alien from all other metals, nature very rarely, if ever, mixes with iron any other metal, while the other metals are very often minutely mixed, and are produced together. ”

“ If too much S or P is present in an ore, it is worthless. This is why the abundant mineral FeS2 cannot be used as a source of iron. From the top of the furnace N, CO, CO2, H2O, etc., escape. These gases are used to heat the air which is forced through the tuyeres, and to make steam in boilers.
267. Steel.—The manufacture of steel and wrought-iron consists in removing most of the impurities from pig-iron. It will be seen that the most common compounds of C, S, Si, and P, are their oxides, and these are for the most part gases. Hence these elements are removed by oxidation. ”