Bauxite

“ Antrim occur with pisolitic iron ore interbedded with the Tertiary basalts, and similar deposits are met with in connexion with the basaltic rocks of the Westerwald in Germany. On the other hand, the more extensive deposits in the south of France (departments Bouches-du-Rhône, Ariège, Hérault, Var) and the southern United States (Georgia, Alabama, Arkansas) are often associated with limestones; in this case the origin of the bauxite has been ascribed to the chemical action of solutions of aluminium sulphate on the limestones. ”

“ Since there is much more aluminum than iron in the earth’s compounds, however, there will never be a shortage, if cost is disregarded. Commercial aluminum is manufactured from the oxide, bauxite. Bauxite is also used directly as an abrasive and also as a refractory. The largest bauxite deposits are controlled politically by the United States and France, with the British Empire in a favorable prospective position. ”

“ Parts of the Flysch of the eastern Alps, the Biancone of Lombardy, and argile scagliose of Emilia, are of Aptian age; so also are the “Trinity Beds” of North America. Deposits of bauxite occur in the Aptian hippurite limestone at Les Baux near Arles, and in the Pyrenees. The Aptian rocks are generally clays, marls and green glauconitic sands with occasional limestones. ”

“ After being dried at 100° C., Antrim bauxite contains from 33 to 60% of alumina, from 2 to 30% of ferric oxide, and from 7 to 24% of silica, the balance being titanic acid and water of combination. The American bauxites contain from 38 to 67% of alumina, from 1 to 23% of ferric oxide, and from 1 to 32% of silica. The French bauxites are of fairly constant composition, containing usually from 58 to 70% of alumina, 3 to 15% of foreign matter, and 27% made up of silica, iron oxide and water in proportions that vary with the colour and the situation of the beds. ”

“ Aluminum is now made from a mineral called "bauxite," found chiefly in Georgia, Alabama, and Arkansas. Mining it is much more agreeable than coal mining, for the work is done aboveground. The bauxite is in beds or strata which often cover the hills like a blanket. First of all, the mine is "stripped,"—that is, the soil which covers the ore is removed,—and then the mining is done in great steps eight or ten feet high, if a hill is to be worked. There is some variety in mining bauxite, for it occurs in three forms. ”

“ In the preparation of alum from clays or from bauxite, the material is gently calcined, then mixed with sulphuric acid and heated gradually to boiling; it is allowed to stand for some time, the clear solution drawn off and mixed with acid potassium sulphate and allowed to crystallize. When cryolite is used for the preparation of alum, it is mixed with calcium carbonate and heated. ”

“ Aluminum Aluminum is the most abundant metallic element in the earth's crust. Bauxite, the ore most commonly used as a source of aluminum, is found primarily in the less industrialized areas of the world. The leading world producer of bauxite in 1971 was Jamaica where 1.8 million short tons were produced. Of this total, 1.7 million tons were imported into the United States. ”

“ If, according to the present method of winning the metal, a bath containing silica as well as alumina is submitted to electrolysis, both oxides are dissociated, and as silicon is a very undesirable impurity, an alumina contaminated with silica is not suited for reduction. Bauxite is a hydrated oxide of aluminium of the ideal composition, Al2O3·2H2O. It is a somewhat Widely distributed mineral, being met with in Styria, Austria, Hesse, French Guiana, India and Italy ”

“ Where the tuffs become fine-grained and free from imbedded stones, they pass into variously-coloured clays. Among these are the "bauxite" and "lithomarge" of Antrim, probably derived from pale rhyolitic tuffs and conglomerates (p. 204) . Associated with these deposits in the same district, is a pisolitic hæmatite, which has been proved to occur over a considerable area on the same horizon. Many of the clays are highly ferruginous. The red streaks that intervene between successive sheets of basalt are of this nature (bole, plinthite, etc.) ”

“ The troops engaged were, on the French side 163,000 men, on that of the allies about 100,000; and the losses respectively about 20,000 and 13,500 killed and wounded.
BAUXITE, a substance which has been considered to be a mineral species, having the composition Al2O (OH) 4 (corresponding with alumina 73.9, water 26.1%) , and thus to be distinct from the crystallized aluminium hydroxides, diaspore (AlO (OH) ) and gibbsite (= hydrargillite, Al (OH) 3) . ”

“ The Bajocian rocks of Europe are mostly limestones of various kinds, very frequently oolitic. At Bayeux, the type district, they are ferruginous oolites; in the Jura and Lorraine a coral limestone overlies a crinoidal variety; calcareous sandy and marly beds occur in Maine and Anjou; in Poitou the limestone is dolomitic and bears nodules of chert. Rocks of the same age, as recognized by their fossil contents, have a wide range; they are found in north Africa, Goa, Somaliland, German East Africa, and north-west Madagascar ”

“ Barite is a secondary mineral of aqueous origin, which has been deposited in veins and cavities in igneous, metamorphic, or sometimes sedimentary rocks. It is most likely to occur in veins in igneous or metamorphic rocks, the barium having been dissolved from certain feldspars and micas by percolating water, and then redeposited in the fissures, as the water came into them. If in sedimentary rocks, the barite veins are usually in limestones. Barite is quite likely to be a gangue mineral for the ores of lead. ”

“ When leucite or nepheline replaces plagioclase, the rock becomes a leucite-basalt, [1] or nepheline-basalt. Some basalts have a glass paste, or "ground-mass," in which the minerals are enclosed.
The lava of Vesuvius may be regarded as a variety of basalt in which leucite replaces plagioclase, although this latter mineral [Pg 261] is also present. Zirkel calls it "Sanidin-leucitgestein," as both the macroscopic and microscopic structure reveal the presence of leucite, sanidine, plagioclase, nephiline, augite, mica, olivine, apatite, and magnetite. ”

“ Such crystals, of short prismatic habit and black in colour, are common as phenocrysts in many basalts, and are hence known as “basaltic augite”; when the containing rock weathers to a clayey material the augite is left as black isolated crystals, and such specimens, usually from Bohemia, are represented in all mineral collections. Though typical of basaltic rocks, augite is also an important constituent of many other kinds of igneous rocks, and a rock composed almost wholly of augite is known as augitite. ”

“ These substances are so intermingled, that it is scarcely possible to conceive that the basalt is posterior to the limestone, or that a basalt vein should have found its way into a vein of limestone without also traversing the amygdaloid. It is probable that the whole vein is of simultaneous formation, and that the substances have separated from each other in consequence of those obscure chemical affinities which regulate the crystallizations of compound rocks. ”

“ This seems also to be the reason why bathing in Mineral waters are such soveraign remedies for multitudes of distempers, especially chronical; for the liquid & warm vehicles of the Mineral particles, which are known to be in very considerable quantities in those healing baths, by the body’s long stay in them, do by degrees steep and insinuate themselves into the pores and parts of the skin, and thereby those Mineral particles have their ways and passages open’d to penetrate into the inner parts, and mingle themselves with the stagnant juices of the several parts ”

“ From the under-surface of the oil, if the bacillus be that of plague, stalactite-like growths of bacilli will form. When disturbed, the stalactite growths break off and fall in snow-like flakes to the bottom of the vessel. No other known bacillus behaves in this way. (See p. 325.) In case of doubt, animal inoculation should be had recourse to: a little of the virus from the patient or a culture is rubbed into a shaven area (1 in. square) on the abdomen of a white rat or a guineapig. ”

“ As soon as the blood is driven out, leaving the nodule pale, make a puncture with the point of a sharp knife. From this puncture a clear fluid exudes; this, dried on a cover glass, stained with carbol-fuchsin, and rapidly decolonized with a weak mineral acid, shows bacilli stained red and very like tubercle bacilli; they differ from that organism, however, in that they are somewhat shorter, and that if the acid be too strong or be allowed to act on them for too long a time, the colour is discharged from them much more readily. ”

“ That is what nature does to a bacillus, literally walls it off in stone. After death when the pathologist's knife cuts down into a lung, the knife is sometimes broken by coming upon what feels like a stone. A stone it really is, a deposit of lime salts in the tissue, around a nest of tubercle bacilli. If one cuts such a stone in two, one finds in the centre bacilli often still alive and perfectly capable of increase, but harmless to the body because nature has built this wall around them. ”

“ One is, the existence in it of vegetable or animal matter, which can be remedied by filtering through sand and charcoal. Another cause is, the existence of mineral matter, especially in limestone countries, producing diseases of the bladder. This is remedied, in a measure, by boiling, which secures a deposit of the lime on the vessel used. The third cause is, the corroding of zinc and lead used in pipes and reservoirs, producing oxides that are slow poisons. The only remedy is prevention, by having supply-pipes made of iron, like gas-pipe, instead of zinc and lead ”

“ Basalt is a heavy igneous rock that is black, dark gray, or dark brown. This rock is made up chiefly of a feldspar mineral, such as labradorite, and a pyroxene mineral, such as augite. Other minerals may be present.
The mineral grains of some basalts are so small that you cannot distinguish them even with a magnifying glass. Other basalts, however, are porphyritic, which means that they contain larger, easily seen crystals and grains of feldspar and pyroxene scattered either through a mass of the small mineral grains or through glassy material. ”

“ The beautiful resinous or pitchstone-like rock from near Airthrey Castle has been found by Mr. Watts to be a glassy hypersthene-augite-andesite, since among its phenocrysts of plagioclase, augite and hypersthene both occur. Magnetite is commonly traceable, and apatite may be occasionally detected. As the result of decomposition, calcite, chlorite and limonite are very generally diffused through the rocks. ”

“ Azurite and malachite occur as individual 54 crystals, but you are more likely to find them as crusts on rocks and on other minerals. Malachite is also found in rounded fibrous masses that resemble bunches of grapes (described then as botryoidal) .
Both azurite and malachite are formed in the same way. Underground waters seep through rocks that contain deposits of copper minerals (such as chalcocite and chalcopyrite) and cause chemical reactions which change these minerals into malachite and azurite. ”

“ It is thought that when the masses of halite and anhydrite pushed toward the earth’s surface, some of the upper part of the halite dissolved. The anhydrite, however, did not dissolve, and it remained on top of the salt column. Then, a part of this anhydrite was altered into the gypsum, limestone, and sulfur that now are found in some of the cap-rocks. Laboratory experiments have shown that the sulfur in the cap-rocks likely formed through the action of sulfate-reducing bacteria. These bacteria, in the presence of petroleum, converted the sulfate in some of the anhydrite into hydrogen sulfide. ”

“ Barytes, or Heavy Spar
The mineral known as heavy spar occurs in very large quantities and in numerous localities. It forms rhombic crystals, which are very often extremely well developed and form flat plates of considerable size. A remarkable peculiarity of this mineral is its high specific gravity, which is due to the barium content. It is found native in all colours, white being the most common.
Chemically, heavy spar is barium sulphate, BaSO4. It can be used as a pigment per se, but only when prepared artificially, the trade name for the product being permanent white, or blanc fixe. ”

“ The basaltic andesites found on the hill-slopes further inland from the springs exhibit no change of such a nature. However, rocks of this description occur at and near the coast about a mile to the westward. One of them, which is light green in colour, might be taken for a limestone, since it effervesces with an acid. When examined in the slide it is shown to be the prevailing basaltic andesite greatly altered. The porphyritic rhombic pyroxene is replaced by viriditic material; the plagioclase phenocrysts are replaced by calcite, secondary silica, and other alteration products ”

“ This is in parts very like an ordinary basalt or anamesite, with a glistening surface and weathering brown. Parts of it are rather porphyritic, having very white felspar crystals up to about 1/4 inch long. I have had slides cut from this; and on examination it proves to be a basalt, the plagioclase being fairly well preserved, the augite sometimes very characteristic, and a good deal of olivine with a granulated dusky aspect like (though on a smaller scale) that described above; there is also a fair quantity of magnetite. ”