Ore

“ That the thing is so, I will prove by a certain similitude or comparison; make proof in what manner you please, of gold or silver Ore, and observe how much good metal that contains, afterwards prove the same in a great quantity upon Coals, and you shall find much less in that, than in your small proof; when nevertheless the contrary ought to be, because a great fire hath a greater force of acting upon the Ore, than a small one; and this is the only cause, because a great quantity requireth a more violent fire than a small one; which is averse to all crude and volatile Minerals. ”

“ Iron Ore.—An ore is a portion of the earth’s substance containing metal for which it is mined and worked; the class to which it belongs depends upon the amount and variety of the metal it contains. Any ore that is to be used for the extraction of a certain metal must contain the metal in sufficient amounts to make the operation profitable. ”

“ The ore melts, the earth of the Lead unites with the phlogiston of the coals, and so is reduced to metal, which runs through the coals, and falls into an earthen vessel placed at the bottom of the furnace to receive it. ”

“ We find our best ore shoots on the sunny sides of the mountains, while the veins on the northern shaded sides where the snow lies till mid-summer and the rocks are cold produce no such rich ore. We begin to realize that our theory is based on fact and proved by observation; and that it justifies us in placing confidence in it, and in acting upon it within reasonable limits. And we marvel that facts so simple and of such easy comprehension and yet of such practical value should receive so little attention from the writers on ore deposits. ”

“ The manner in which metallic substances are distributed through the earth's crust, and more especially the phenomena of those nearly vertical and tabular masses of ore called mineral veins, from which the larger part of the precious metals used by man are obtained,—these are subjects of the highest practical importance to the miner, and of no less theoretical interest to the geologist. ”

“ What is the fineness and goodnefs of the Ore, by which the Mine is wont to be estimated? And what are the marks and characters, that distinguish one sort from another?
64. What proportion of Metal it affords? (As in our Iron-mines 'tis observed, that about three Tuns of Iron-stone will afford one Tun of Metal: And I have had Lead-Ore, which an Ingenious man, to whom I recommended such Tryals, affirm'd to me to afford three parts in four of good Lead.) ”

“ The production of ore which occurs in the upper parts of the veins, furnishes us with the saline ores; for here the water, air and earth are principally active. In the upper depths are found most frequently the oxygenized metals, or as they are called mineral spars, as spathic-iron, malachite, calamine, lead-spar, pyromorphite, &c. ”

“ In iron ore, the metallic oxide or carbonate makes up nearly the whole rock; in gold ore, the metal is the merest incidental constituent, from the petrologic point of view.
Concentration.—The essential fact in the formation of ores is the unusual concentration of the metal. There are vast quantities of all the metals disseminated through the rock substance of the earth and even throughout the hydrosphere, but they do not constitute ores because they have no economic value. They become ores when concentrated in accessible places to a workable richness. ”

“ The ore is found in detached pieces and solid masses, in beds, in red clay, accompanied by sulphate of barytes, calcareous spar, blende, iron pyrites, and quartz. The ore is of that kind called, by mineralogists, lead-glance, or galena, and is the sulphuret of lead, of chemistry. As it is dug up or quarried from the adhering spar, it presents a very rich appearance. It has a [Pg 171] broad, glittering grain, of a lead-gray colour, which passes into a bluish shade. The ore is easily broken by the blow of a hammer, and may be pounded to a fine powder, still preserving its glittering appearance. ”

“ We are accustomed to admire the wisdom and foresight that spread layers of iron ore and layers of coal near each other in the crust of the earth that the one might give the melting heat which the other needed ”

“ OF OPAKE OBJECTS.
Ores and minerals afford an immense variety of very beautiful and splendid objects. From amongst these the observer may select the peacock or coloured copper ore, green crystallized ditto, [609] lead ore, crystallized ditto, crystals of lead, small grained marcasites, coloured mundic, cinnabar, native sulphur, needle and other antimony, moss copper, &c. A mixture of small pieces of ores, &c. of different kinds, produces a pleasing effect. Sands in general exhibit something not discoverable with the naked eye. ”

“ The ore is then conveyed into a vessel containing an absorbing fluid metal, so constructed that every particle of the ore is brought into contact with the metal. For the production of reducing gases, steam and air are passed through highly heated materials, having an affinity for oxygen, and the gases so produced are utilized for raising the ore to a high temperature. ”

“ After a while—an immensely long while—there can be little doubt that man discovered that the ore of metals, which is found in the ground, can be fused, that is to say, melted by fire; that it can be separated from its earthy surroundings, and so be made useful. ”

“ I compare such preachers to a miner, who should go to the quarry where he raised the ore, and taking his sledge in his hand, should endeavor to form bars of iron of the ore in its rough state, without a furnace to melt it, or a rolling-mill to roll it out, or molds to cast the metal, and conform the casts to their patterns. ”

“ The ore is broken up into pieces at the mouths of the shoots; the least rich lumps and those containing a large amount of other minerals are set apart for consumption at convenience; while the best pieces are sorted into five classes, their estimated values ranging from about sixteen to one thousand pounds per ton. ”

“ Which being done, let the Ore of ☉ or ☽ being rightly prepared, be put into the last Chamber, that it may be made hot by degrees, and burn, but not melt, which may be hindered by the help of the little door, and the fire may be governed at a beck, according as it shall be necessary, and the Mineral requireth, or shall be able to suffer; the Minerals are sometimes to be stirred and turned well about in all parts, with an Iron Hook or Ladle, that they may be well Calcined. ”

“ Sometimes the amount of ore in sight will be considered to be a rectangular block, limited by the outcrop of the vein, the depth of the shaft, and the extreme points of the levels, diminished by the amount extracted. ”

“ For although it should be mixed with Lead, the Minera of Lead, or Salt of Lead, yet they would not remain conjoin’d, but the Lead is easily melted, floweth, and leaveth the Ore, which by strong blowing is reduced into Scoria, retaining much gold, which so is lost, as well as the other which flew away in smoak, and at the best but a very little saved, which hath entred the Lead. ”

“ The concentration of ores always proceeds by steps or stages. Thus the ore must be crushed before the minerals can be separated, and certain preliminary steps, such as sizing and classifying, must precede the final operations which produce the finished concentrates. ”

“ A metalliferous rock is spoken of as an ore when it contains metallic minerals (or in some cases non-metallic minerals, such as sulphur) in such quantities and mixtures as to make possible their profitable extraction. The metal contained in an ore is sometime found in its elemental form, as in the case of gold or platinum, but more frequently as a sulphur compound, or as an oxide carbonate or silicate. Often several different forms of one metallic element are found in the same deposit and several metals are often found together. ”

“ The assay of an ore for gold or silver consists of two operations. In the first the gold or silver is made to combine or alloy with metallic lead, the other constituents of the ore being separated from the lead as slag. In the second, the lead button containing the gold or silver is cupelled and the resulting gold or silver button is weighed. ”

“ The ore is thrown into a large furnace, like the blast furnaces of the ironworks, and in the heat of the fire the bonds between copper and oxygen are loosened and the superior attractions of the carbon in the fuel entice the oxygen away, leaving the metal comparatively pure. ”

“ The principal ore bodies that have been worked in recent years have been of irregular shape, both horizontally and vertically, and usually have been between 50 and 200 feet wide and from a few to as much as 100 feet high. ”

“ An ore formed by direct processes of sedimentation has sometimes been called primary, whereas an ore formed by later enrichment of these sediments has been called secondary. An ore formed directly by igneous processes has been called primary, while an ore formed by enrichment of such primary ore by later processes has been called secondary. ”

“ When we compare the first and second tabulations with the third it is at once apparent that with the possible although only occasional exception of iron the production of an ore-body from the normal rocks which constitute the outer mass of the earth requires the local concentration of each of the metals by one or several geological processes, and to a degree that is only occasionally developed in the ordinary course of nature. ”

“ If the ore body is formed as a single episode under simple geologic conditions, the interpretation of the possibilities in the situation may be quite different from the interpretation applied where the history has been more complex. ”

“ We propose to display on a magnificent scale the best specimens of our workmanship. It is the intention of this department to obtain an exhibit from the mine or ore bed in which our people are at work, whether it be coal, slate, marble, fine sand and gravel, ore of iron, copper, tin, zinc, silver or gold, or any peculiar geological deposit. ”

“ Iron ore, tin, copper and tungsten are extracted from the earth, refined, put to some use or wasted as the case may be, but they are gone. They may be replaced by other minerals. Through geological ages they may redeposited in the earth's crust. ”

“ The iron ore was an Artificial Object produced by Man from Natural Resources known as ore deposits. So the barrel holding those potatoes at that retail store proves to be throughout its whole Economic history nothing but a combination of many kinds of Artificial Objects every one of which has been produced and all of which have been combined by Man from and upon and within the Natural Resources of earth and air and light and heat and electricity and other natural characteristics of the planet that Man inhabits. ”

“ Oxidised ore is always found on the top levels. At a depth of 300 feet the sulphide ore, which contains telluride, is reached.
Going through the various drives we often met miners walking along to different parts of the mine. We were all carrying candles, so could peer into each other’s faces, and the look of surprise on some of them at seeing a strange lady rambling about underground was quite amusing. Then we would come on a group of workmen at a stope; then sounds of the rock-drill would make me curious to go in its direction. ”

“ As soon as the ore in the furnace has become ignited the carbon and oxygen unite and form carbonic acid, which escapes, and the metal fuses at last and runs away. The coal and ore are continually added year after year. ”

“ Seldom, however, do the processes go far enough in nature to produce an ore which can be used directly without some further mechanical sorting. Ore minerals concentrated in placers are those which resist abrasion and chemical solution during the processes of weathering and transportation, and which have a density sufficiently high so that they are partially sorted out and concentrated from the accompanying quartz and other minerals. ”

“ Analyses made of each car or boat load of ore by the furnace chemists representing the buyer must check very closely the analyses made by the mine chemists for the seller, as the price of every ton of ore is based on its iron and its phosphorus contents and the percentages of certain other constituents present. ”

“ All along the Appalachian Mountains the iron has been gathered in beds which are being mined. These beds of ore are usually mixed with clay and other earthy substances from which the metal can be separated only by melting. ”

“ In those veins where there is no copper ore, the second and third heaps are obviously absent. When present, the compound ore is broken into smaller pieces with a mallet, and the fragments are sorted anew.
3. Stamping.—The stanniferous fragments (No. 1.) are stamped into a sand, of greater or less fineness, according to the dissemination of the tin-stone in the gangue. The determination of the size of the sand, is an object of great importance. ”

“ The ore (the author remarks) is the lead glance, galena, or sulphuret of lead. It is very rich and beautiful, and specimens in our possession fully confirm Mr. Schoolcraft's account; they have a very broad and perfectly foliated fracture, and a high degree of metallic lustre; they break in cubical fragments, and the minutest portions still retain this form.
We have already observed that large fragments are found loose in the earth: they sometimes weigh four or five pounds; we have such specimens from these mines ”

“ From the stopes the ore, as it is blasted out, is shovelled into chutes running down to some drift where there are men with cars. Each car holds about a ton of ore, and after being filled it is pushed along the drift and upon a cage which raises it to the surface. ”

“ We started with the pure metal, and all our endeavours have been directed solely towards reconstructing the ore. It is the metal itself we are now about to study. Nothing could be easier, for this time we have a simple element to deal with. ”

“ Where an acid substance, like silica, is balanced by basic constituents like lime and magnesia, considerable amounts of both may be used. Excessive moisture content may spoil an ore because of the amount of heat necessary to eliminate it in smelting. ”