Distillation retort

Distillation retorts and furnaces are used either to reclaim zinc from alloys or to refine crude zinc. Bottle retort furnaces consist of a pear-shaped ceramic retort (a long-necked vessel used for distillation). Bottle retorts are filled with zinc alloys and heated until most of the zinc is vaporized, sometimes for as long as 24 h. Distillation involves vaporization of zinc at temperatures from 980 to 1250°C (1800 to 2280°F), and condensation as zinc dust or liquid zinc. Zinc dust is produced by vaporization and rapid cooling, and liquid zinc results when the vaporous product is condensed slowly at moderate temperatures. 

Distillation retort, — Feeding opening for potassium persulphate. 1 Droplets separator, 4 — Insulation of the retort. — Steel jacket. tf — Separator of entrained droplets. 7 — Porcelain rings. — Deplileginator. 9 - - Cooling water inlet, 10 -- Cooling water outlet, 11 — Water vapour offtake to aluminium condenser. 

The crucible containing the zirconium sponge and MgClj is transferred to the vacuum distillation retort, shown in Fig. 7.13, where it is supported, upside down, over a perforated, stainless steel funnel. The air in the retort is evacuated, and the crucible is heated to 900 to 920°C to melt the MgGj. which partially drains off the sponge. Salt still wetting the sponge is distilled at this temperature to a water-cooled jacket inside the retort. 

Now, we return to the First Perfection, also called the distillation. The alchemist mixes the pulverized metals to form the Compost. Any mixture of metals is also a Rebis. It is placed into a distilling retort (say a 150ml flask empting into a 250ml receiver). The proportions are 3 parts... 

The turnings are then placed in a stainless-steel, perforated basket of sufficient size to take the whole batch, i.e. about 36 in. deep by 24 in. diameter. The basket is placed inside the vacuum distillation retort shown in Fig. 6.11. This is about 8 ft deep and is divided into a lower, mild-steel portion, heated by a furnace, joined by a cooled neoprene gasket to an upper, stainless steel portion, which acts as a condenser. The furnace is in the form of an evacuated bell with a rating of 50 kW, although only about 20 kW is used in a distillation. The retort is capable of evacuation to a pressure of 100 /Li mercury equivalent by means of an oil diffusion pump, and the furnace can be evacuated to 1 mm mercury equivalent by a high-capacity mechanical pump, which serves five furnaces. 

Cooling is carried out under a slight positive pressure of helium and is assisted by blowing a stream of air between the reactor and its heating elements. The furnace is opened at a temperature of ISO C, by removing the top ziiconium chloride container and baffles. The reduction crucible itself may then be taken out. Exposed sponge is removed from the surface of the reaction mass and the crucible is then transferred to a distillation retort. 

The reaction is carried out in a lead retort one suitable for the laboratory can be made from a piece of lead piping, bent like a retort and closed at the shorter end. This is charged with fluorspar and the acid and heated, and the hydrogen fluoride is distilled into a polythene vessel. 

In order to save the cost of the distilling-flask (which after the above treatment is useless for further work), the mixture may be distilled from a small retort made by blowing a suitable bulb on the end of a rather thick-walled tube of about 8-10 mm. internal diameter the tube is then bent through almost 90° a few cm. above the bulb, cut to a suitable length, and the Open end fitted into the boiling ube as before. 

Anhydrous sodium sulphide. The hydrated salt, NajS.QH O, is heated in a Pyrex distilling flask or retort in a stream of hydrogen or of nitrogen until water ceases to be evolved. The solid cake of anhydrous sodium sulphide is removed from the vessel with the aid of a copper wire hook or by other suitable means. No attempt should be made to fuse the sodium sulphide since at high temperatiues sodium sulphide is readily oxidised to sodium sulphate. 

Equip a 3 litre three-necked flask with a thermometer, a mercury-sealed mechanical stirrer and a double-surface reflux condenser. It is important that all the apparatus be thoroughly dry. Place 212 g. of trimethylene dibromide (Section 111,35) and 160 g. of ethyl malonate (Section 111,153) (dried over anhydrous calcium sulphate) in the flask. By means of a separatory funnel, supported in a retort ring and fitted into the top of the condenser with a grooved cork, add with stirring a solution of 46 g. of sodium in 800 ml. of super dry ethyl alcohol (Section 11,47,5) (I) at such a rate that the temperature of the reaction mixture is maintained at 60-65° (50-60 minutes). When the addition is complete, allow the mixture to stand until the temperature falls to 50-55°, and then heat on a water bath until a few drops of the liquid when added to water are no longer alkaline to phenolphthalein (about 2 hours). Add sufficient water to dissolve the precipitate of sodium bromide, and remove the alcohol by distillation from a water bath. Arrange the flask for steam distillation (Fig. this merely involves... 

Pyrolysis. Pyrolysis, eg, retorting, destmctive distillation, carbonization, is the thermal decomposition of an organic material ia the absence of... 

The recorded chronology of the coal-to-gas conversion technology began in 1670 when a clergyman, John Clayton, in Wakefield, Yorkshire, produced in the laboratory a luminous gas by destmctive distillation of coal (12). At the same time, experiments were also underway elsewhere to carbonize coal to produce coke, but the process was not practical on any significant scale until 1730 (12). In 1792, coal was distilled in an iron retort by a Scottish engineer, who used the by-product gas to illuminate his home (13). 

Temperature and Product Yields. Most oil shale retorting processes are carried out at ca 480°C to maximize liquid product yield. The effect of increasing retort temperature on product type from 480 to 870°C has been studied using an entrained bed retort (17). The oil yield decreased and the retort gas increased with increased retorting temperature the oil became more aromatic as temperature increased, and maximum yields of olefinic gases occurred at about 760°C. Effects of retorting temperatures on a distillate fraction (to 300°C) are given in Table 6. 

Retorting temperature of distillate (reduced to 300°C) Saturates, vol % Olefins, vol % Aromatics, vol %... 

When using a continuous vertical retort, phenols, cresols, and xylenols are collected in one fraction. A typical range of primary distillation fractions is given in Table 2. 

Redistillation. For certain appHcations, especially those involving reduction of other metal compounds, better than 99% purity is required. This can be achieved by redistillation. In one method, cmde calcium is placed in the bottom of a large vertical retort made of heat-resistant steel equipped with a water-cooled condenser at the top. The retort is sealed and evacuated to a pressure of less than 6.6 Pa (0.05 mm Hg) while the bottom is heated to 900—925°C. Under these conditions calcium quickly distills to the condensing section leaving behind the bulk of the less volatile impurities. Variations of this method have been used for commercial production. Subsequent processing must take place under exclusion of moisture to avoid oxidation. 

The contents of the flask while still hot are poured into a 30-cm. evaporating dish and the alcohol is evaporated on a steam bath. The dry salt is pulverized and thoroughly mixed with 390 g. of calcium oxide, placed in a 2-I. copper retort (Note 3), and heated with the full flame of a Meker burner. The distillate is placed in a distilling flask and heated on a steam bath all material distilling under 90 is removed and discarded. The residue is then allowed to stand over solid potassium hydroxide for twelve hours and is finally fractionated. The dimethyl-pyridine distils at i42-i44°/743 mm. The yield is 35-36 g. or 62-64 per cent of the theoretical amount based on the 3,5-dicarb-ethoxy-2,6-dimethylpyridine, or 30-36 per cent based on the original ethyl acetoacetate. 

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