The science of calcination consists of the method by which the sulphide ores, having been crushed to a proper degree of fineness, are raised to a sufficient temperature and brought into intimate contact with atmospheric air.
The precipitates are then collected, and after calcination in a special furnace for the purpose of oxidising the zinc, are smelted in the usual manner.
But if you further continue the Calcination till you have perfectly Incinerated the Tartar, & kept it long enough in a Strong fire, the remaining Calx will be White.
Which Geber knew very well: the compleat calcination of Sol, is most difficult: He renders the causes thereof.
A kind of oven, or reverberatory furnace, used for the calcination of sand and potash, and converting them into frit.
The substance which remains when a metal or mineral has been subjected to calcination or combustion by heat, and which is, or may be, reduced to a fine powder.
The common practice in the glass-houses is to conduct the calcinationby exposing the metal, placed on tiles, in the leer or annealing arch of the furnace; a plan both convenient and economical.
By the calcination the sulphur in the compound is first oxidised, sulphate of sodium is formed, and at the same time the chlorine from the sodium chloride unites with the copper to form cupric chloride.
The method of conducting the process of calcination depends on the nature of the body operated on.
When the ores were very rich, the preliminary calcination and fusion were omitted, and the alloy of lead at once formed.
The hydrochloric acid and other gaseous products evolved during the calcination are condensed as 'tower liquor' in ordinary condensing towers, and the product is used in the subsequent process of lixiviation.
In the essay of ores, and in all the common operations of the laboratory, the calcinationor oxydation of metals is usually performed in a dish of baked clay, Pl.
At the end of twelve days, seeing that the calcination of the mercury did not at all increase, I extinguished the fire, and allowed the vessels to cool.
Three hours calcination were necessary to discharge the whole of the air from the Magnesia.
It was remarkable that calcination had not reduced the powder in bulk, in proportion to the diminution of its weight.
It slowly precipitated the corrosive sublimate of mercury, in the form of a black powder; whereas before calcination a dark red precipitate was formed from the same substance.
If plaster of Paris is to be made, calcination is carried out at about 204 Deg.
Both processes are inferior in economy to calcination in rotatory kilns, a process which may be regarded as the method of the present and the immediate future.
The coarser varieties of alabaster are converted by calcination into plaster of Paris, whence they are sometimes known as ``plaster stone.
The phlogistic theory of the processes of calcination and combustion necessitated the view that many acids, such as those produced by combustion, e.
The strata of coal necessary for the production of this quantity of lime require to be four inches thick, and the time necessary for calcination was, as stated already, 50 hours.
Again, was it possible to effect the perfect calcination of the interior of the lumps alluded to without bestowing upon the outer portions a greater heat than was necessary for the purpose, causing a wasteful expenditure of both time and fuel?
Salts, remaining in the ash obtained by the calcination of the flour, in a proportion not exceeding 2 per cent.
The calcination is effected in reverberatory furnaces, or in muffle furnaces, if the sulphur is to be recovered.
Also, however slowly the calcination may be conducted, there is always more or less copper sulphide left unchanged, and some copper oxide formed.
It may also be accomplished by calcination with ferrous sulphate, or other easily decomposable sulphates, such as aluminium sulphate.
Calcination with ferrous sulphate converts all the copper sulphide into sulphate.
Calcination is only advisable for ores which contain relatively much iron pyrites and little copper pyrites.
After the calcinationthere is a perfectly purified salt [Symbol: Salt] of absolute transparence.
The process of distillation is to be accomplished slowly, so that the spirits may not escape.
The realm of fairy tales is indeed—and the psychoanalyst can confirm this statement—a Pratum felicitatis, in spite of all dangers and accidents which we have there to undergo.
He established as fundamental that combustion and calcination were attended by an increase of weight, and concluded, as did Jean Rey and John Mayow in the 17th century, that the increase was due to the combination of the metal with the air.
The calcination of an ore is a work occupying a good deal of time, and, in most cases, it is better to take advantage of the desulphurizing power of red lead or nitre.
If the temperature during calcination has been too low sulphates are formed, which are again reduced to sulphides in the subsequent fusion.
Consequently, in such cases, it should be removed by calcination unless it is known that its presence will not interfere.
In the calcinationof somewhat fusible minerals, the roasting should be done at a low temperature to avoid clotting; arsenic and sulphur being with difficulty burnt off from the clotted mineral.
The calcination is effected as follows:--Weigh up 20 grams of the powdered ore and place it in a wide-mouthed crucible sufficiently large to perform the subsequent melting down in.
Calcination is hastened by stirring with a platinum wire.
When calcination is not admissible it may be destroyed by heating with strong sulphuric acid and bichromate or permanganate of potash or by fusion with nitre.
The stirrer should not be removed till the calcination is finished.
Lead renders the assay more difficult, since after calcination it remains as lead sulphate, and in the fusion for coarse copper reappears as a regulus on the button.
The lime resulting from the calcination of magnesian limestone appears to have an injurious action on vegetation, unless applied in quantities considerably less than common lime, when it is found to fertilize the soil.
Animal charcoal, as it is less correctly called, is the black carbonaceous substance into which bones are converted by calcination in close vessels.
Scratches fluor spar; affords water by calcination in a glass tube; infusible at the blow-pipe; and effervesces slightly when fused with glass of borax.
As it is the oxide of cobalt which has the colouring quality, the calcination serves the purpose of oxidizement, as well as of expelling the foreign matters.
The next process is the calcination in the burning-house; which includes several reverberatory furnaces.
When the calcination is complete, the heap diminishes to one half its original bulk; it is covered with a light reddish ash, and is open and porous in the interior, so that the air can circulate freely throughout the mass.
The yellow ochres may be easily rendered red or reddish brown by calcination in a reverberatory oven, which oxidizes their iron to a higher degree.
In such an apparatus the calcination is continuous.
But it may be said, that combustion always diminishes the volume or mass, on account of the quantity of matter it consumes; and that, on the contrary, calcination increases the weight of many substances.
Now a mirror twelve feet broad by six feet high, would be a large and cumbersome machine; yet we might conquer these difficulties if the product of the calcination were considerable enough to surpass the expense of the consumption of wood.
If the fire be continued, this lime by longer calcination, becomes more poignant; and that drawn from furnaces, where the calcination has subsisted for five or six months together, is still more so.
This demonstrates that the more or less easy calcination and fusion produces the same effects relatively to the progress of heat.
Cinders and other residue of the most combustible matters, demonstrate that fire has calcined all the parts it has not burned, and consequently, a little calcination is found here with combustion.
I fear, therefore, much that the stone not being touched by the heat on every side at once, the calcination would be slower, and the produce less.
Calcination generally received, is, with respect to fixed and incombustible bodies, what combustion is to volatile and inflammable.
Experience alone can decide this, but it would be at least necessary to attempt it on gypsous matters, whose calcination is as quick again as calcareous stone.
A piece of the hardest limestone, when deprived by calcination of its carbonic acid, becomes a body which may be crushed by the least pressure, or if treated with water assumes double its original bulk and falls to powder.
The walls constructed of freestone are seriously deteriorated, the stone being destroyed by disintegration and the calcination of the limestone.
This basis we know to be an earth capable of being converted into Lime; and that it is actually converted into Quick-lime by the calcination necessary to produce the Phosphorus.
In order to defend it from the contact of the air, which always accelerates the calcination of metallic substances, the mixture is to be covered with Sea salt; and the addition of pitch helps to increase the quantity of phlogiston.
Alkalis freed of their superfluous humidity by calcination attract the moisture of the air, but not so strongly as Acids: so that it is easier to procure and preserve them in a solid form.
I took several stones of different kinds, some of which produced by calcination a very strong Lime, and others but a very weak one.
Charcoal-dust is made an ingredient in the composition of the vessels used on this occasion, in order to prevent the calcination of the Lead.
Tartar is decomposed by calcination in the open fire.
If the calcination be continued it becomes yellow, and at last of a beautiful red.
Of these processes are the calcination of metals, a mixture of iron-filings and sulphur, liver of sulphur, the burning of phosphorus, and the effluvia of flowers.
It has been observed, that the comparative heat of bodies containing phlogiston is increased by calcination or combustion; so that the calx of iron has a greater capacity for heat, and therefore contains more latent heat, than the metal.
It is procured by extracting the dephlogisticated part of the common air, as by the calcination of metals, &c.
This enamelling appears to have been done, not by melting on any vitreous composition, as is practised at the present day, but by the effect of calcination for some time in a low red heat.
