Sulphur sublimation

A. Y. P. d Antonj noticed,1 in 1765, that the more rarefied the atm. in which the powder burns, the more difficult is the ignition, and that the powder melts when heated in vacuo. Similar results were obtained by G. W. Muncke (1817). J. N. Hearder (1865) electrically heated a platinum wire in contact with gunpowder in vacuo, no explosion occurred, the nitre melted, and sulphur sublimed but... 

RESINA TERRE POTABILIS — Sulphur Sublimed and Reduced to a Liquid, Balsam, or Oil. 

Flowers of sulohur. 4354 In dtsulUng sulphur from Impurities, the first vapors are condensed as a yellow powder called flowers of sulphur sublimed sulphur. 

Mode of Preparation.—Crude sulphur, imported from Sicily, Naples, the Eoman States, and other volcanic districts, is placed in a retort connected with a brick chamber. On the application of heat to the retort the sulphur sublimes into the chamber, to the walls of which it attaches itself, while the earthy impurities remain behind. When a sufficient quantity of the sulphur has collected on the walls of the condensing chamber it is scraped off for use. 

Correct operation of the burner is essential for successful functioning of the total sulphonation plant. Unbumt sulphur may evaporate and will pass upstream with the process gas causing sulphur sublimation deposits in filters and catalyst tower ("yellow fever"). Subsequent local burning of sulphur can cause severe damage to equipment such as the SO2 cooler, the SO3 filter. 

Crystallizes from water in large colourless prisms containing 2H2O. It is poisonous, causing paralysis of the nervous system m.p. 101 C (hydrate), 189°C (anhydrous), sublimes 157°C. It occurs as the free acid in beet leaves, and as potassium hydrogen oxalate in wood sorrel and rhubarb. Commercially, oxalic acid is made from sodium methanoate. This is obtained from anhydrous NaOH with CO at 150-200°C and 7-10 atm. At lower pressure sodium oxalate formed from the sodium salt the acid is readily liberated by sulphuric acid. Oxalic acid is also obtained as a by-product in the manufacture of citric acid and by the oxidation of carbohydrates with nitric acid in presence of V2O5. 

The extent of dissociation at a given temperature can be determined by measuring the density of the vapour. Since anhydrous sulphuric acid is less volatile than hydrogen chloride, ammonium sulphate does not readily sublime on heating some ammonia is evolved to leave the hydrogensulphate ... 

B. With 70 per cent, sulphuric acid. Reflux 1 g. of the substance (e.g., benzanilide) with 10-15 ml. of 70 per cent, sulphuric acid (4 3 by volume) for 30 minutes. Allow to cool and wash down any acid which has sublimed into the condenser with hot water. Filter off the acid, wash it with water, and examine for solubility, etc. Render the filtrate alkaline... 

The growth of large crystals at the expense of small ones occurs, not only in solutions, but also under conditions which resemble even more closely the growth of large drops, i.e., by sublimation. The phenomenon has been observed in the case of sulphur and of sulphur trioxide in an evacuated space, and in the case of camphor crystals condensed from the vapour on a cold glass surface. 

Simple sublimation is a batch-wise process in which the solid material is vaporised and then diffuses towards a condenser under the action of a driving force attributable to difference in partial pressures at the vaporising and condensing surfaces. The vapour path between the vaporiser and the condenser should be as short as possible in order to reduce mass-transfer resistance. Simple sublimation has been used for centuries, often in very crude equipment, for the commercial production of ammonium chloride, iodine, and flowers of sulphur. 

Lion has been made out of the volatile blood of the Green Lion hence, they are of one nature, and the unfixed blood again renders that which is volatile fixed, and the fixed blood in its turn fixes that which is volatile, as it was before its solution. Then foster it in gentle heat, until the whole of the mercury is dissolved, and you obtain the second ferment (by nourishing the fixed sulphur with that which is not fixed), as all Sages unite with me in testifying. Afterwards this becomes, by sublimation with spirit of wine, of a blood-red colour, and is called potable gold. 

Dibenzotellurophene Tellurium powder (6 g, 47 mmol) and dibenzothiophene S.S -diox-ide (8 g, 37 mmol) are mixed thoroughly, the mixture is carefully heated under an atmosphere of carbon dioxide until evolution of sulphur dioxide commences, and the temperature is then regulated to achieve a steady evolution of sulphur dioxide. From time to time the sublimed dibenzothiophene dioxide is melted and allowed to flow back into the reaction mixture. After 36 h, the mixture is cooled to 20°C and extracted with boiling acetone. The extract is evaporated to dryness, the solid residue is washed several times with cold ethanol, and the washings are collected and evaporated. The residue is steam distilled and the product is recrystallized from light petroleum ether. Yield 1.0 g (10%) m.p. 93°C. 

Some think that Sulphur is a Vitriol sublimed in the Earth, because these mixts are very often found near each other that there is a great deal of Sulphur in the mass of Mineral Vitriol, and that the Acid Spirits which are drawn from them both are wholly alike. 

When mineral sulfur is sublimed, the condensed sublimate is called flowers of sulphur, which in those days had medicinal uses. This operation is intended only to rarifie the Sulphur, that being rendered more open, it may work the better. Note again the mechanical explanation. 

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