Iron vessel

For temperatures up to 100°, a water bath or steam bath is generally employed. The simplest form is a beaker or an enamelled iron vessel mounted on a suitable stand water is placed in the vessel, which is heated by means of a flame. This arrangement may be used for non-inflammable liquids or for refluxing liquids of low boiling point. Since numerous liquids of low boiling point are highly inflammable, the presence of a naked flame will introduce considerable risk of fire. For such liquids a steam bath or an electrically-heated water bath, provided with a constant-level device, must be used. If the laboratory is equipped with a... 

Once purification of the niobium has been effected, the niobium can be reduced to the metallic form. The double fluoride salt with potassium, K2NbFy, can be reduced using sodium metal. The reaction is carried out in a cylindrical iron vessel filled with alternating layers of K NbF and oxygen-free sodium ... 

Distillation. This is the point at which refining begins and was the first method by which petroleum was refined. Originally, distillation (qv) involved a batch operation in which the stiU was a cast-iron vessel mounted on brickwork over a fire and the volatile materials were passed through a pipe or gooseneck which led from the top of the stiU to a condenser. The latter was a coil of pipe, or a "worm" (hence the expression worm end products), immersed in a tank of miming water. 

In a batch process (176), a glass-lined jacketed iron vessel is charged with either sulfur monochloride or sulfur dichloride and about 1% of antimony trichloride as a catalyst. Chlorine is introduced into the reactor near the bottom. Liquid oleum is added to the reactor at such a rate that the temperature of the reaction mass is held at ca 25°C by the use of cooling water in the jacket. 

States or Australia. In some cases, pot stills, arranged in cascade, are still used. The more sophisticated plants employ one or more carbon steel or cast-iron vessels heated electrically and equipped with temperature controls for both the bulk Hquid and the vessel walls. Contact time is usually 6—10 h. However, modem pitches are vacuum-distilled, producing no secondary quinoline insolubles, to improve the rheological properties. 

Tin [7440-31 -5] is one of the world s most ancient metals. When and where it was discovered is uncertain, but evidence points to tin being used in 3200—3500 BC. Ancient bron2e weapons and tools found in Ur contained 10—15 wt % tin. In 79 ad, Pliny described an alloy of tin and lead now commonly called solder (see Solders and brazing alloys). The Romans used tinned copper vessels, but tinned iron vessels did not appear until the fourteenth century in Bohemia. Tinned sheet for metal containers and tole (painted) ware made its appearance in England and Saxony about the middle of the seventeenth century. Although tinplate was not manufactured in the United States until the early nineteenth century, production increased rapidly and soon outstripped that in all other countries (1). 

Toluene is continuously nitrated to mononitrotoluene in a cast-iron vessel, 1 m diameter, fitted with a propeller agitator 0.3 m diameter rotating at 2.5 Hz. The temperature is maintained at 310 K by circulating 0.5 kg/s cooling water through a stainless steel coil 25 mm o.d. and 22 mm i.d. wound in the form of a helix, 0.80 m in diameter. The conditions are such that the reacting material may be considered to have the same physical properties as 75 per cent sulphuric acid. If the mean water temperatute is 290 K, what is the overall coefficient of heat transfer ... 

Brown. R.W., Scott, M.A. and Toyne, C. Tram. Inst. Chem. Eng. 25 (1947) 181. An investigation of heat transfer in agitated jacketed cast iron vessels. 

Silverstein, J. L. et al., Loss Prev., 1981,14, 78 Nitrobenzene was washed with dilute (5%) sulfuric acid to remove amines, and became contaminated with some tarry emulsion that had formed. After distillation, the hot tarry acidic residue attacked the iron vessel with hydrogen evolution, and an explosion eventually occurred. It was later found that addition of the nitrobenzene to the diluted acid did not give emulsions, while the reversed addition did. A final wash with sodium carbonate solution was added to the process [1]. During hazard evaluation of a continuous adiabatic process for manufacture of nitrobenzene, it was found that the latter with 85% sulfuric acid gave a violent exotherm above 200° C, and with 69% acid a mild exotherm at 150- 170°C [2],... 

Benzyl acetate was prepared by addition of benzyl chloride (containing 0.6% pyridine as stabiliser) to preformed sodium acetate at 70°, followed by heating at 115°, then finally up to 135°C to complete the reaction. On one occasion, gas began to be evolved at the end of the dehydration phase, and the reaction accelerated to a violent explosion, rupturing the 25 mm thick cast iron vessel. This was attributed to presence of insufficient pyridine to maintain basicity, dissolution of iron by the... 

Prolonged action of calcium chloride solution upon the zinc coating of a galvanised iron vessel caused slow evolution of hydrogen, which became ignited and exploded. 

Sodium amide is prepared by passing a stream of dry ammonia over metallic sodium at 300-400° taken in an iron vessel. 

The reaction just described is carried out technically on a large scale in iron vessels provided with stirrers, for /9-naphthol, as well as the numerous sulphonic acids which can be obtained from it by the action of sulphuric acid, is widely used for the preparation of azo-dyes. Moreover, by the action of ammonia under pressure, /3-naphthylamine is produced from /S-naphthol ... 

The color of the product is nearly white if the iron vessels are carefully cleaned but may be considerably on the gray side. 

Gadolinium is produced from both its ores, monazite and bastnasite. After the initial steps of crushing and beneficiation, rare earths in the form of oxides are attacked by sulfuric or hydrochloric acid. Insoluble rare earth oxides are converted into soluble sulfates or chlorides. When produced from monazite sand, the mixture of sand and sulfuric acid is initially heated at 150°C in cast iron vessels. Exothermic reaction sustains the temperature at about 200 to 250°C. The reaction mixture is cooled and treated with cold water to dissolve rare earth sulfates. The solution is then treated with sodium pyrophosphate to precipitate thorium. Cerium is removed next. Treatment with caustic soda solution fohowed by air drying converts the metal to cerium(lV) hydroxide. Treatment with hydrochloric or nitric acid sol-... 

PrqparaHcm,—1. By boiling in an iron vessel a solution potassie carbonate with calcic hydrate —... 

Ammonium carbonate is prepared on a large scale by distilling an intimate mixture of ammonium sulphate with twice its weight of chalk in cylindrical cast-iron vessels, 7 to 10 ft. long and 1J ft. diameter, and fitted with movable leaden covers at each end. Several retorts are heated in one furnace. The vapours from the- retorts are led into stone chambers where the carbonate,is deposited as a crust... 

After analysis each form of nitrocellulose (guncotton, collodion cotton, pyror collodion cotton) is batched separately into a linen bag which for convenience and safety is stored in an air-tight iron vessel (to protect the nitrocellulose from drying up and becoming dusty). Nitrocellulose is batched by charges, the size of which depends on the dimensions and the type of apparatus used. In France, for instance, a total charge of nitrocellulose (CPt and CP2) is 20 kg when dehydrated in a hydraulic press or 30 kg when dehydrated in a centrifuge. 

On the first application of sulphuric add to this purpose, the operation was performed in iron retorts. Vessels of platinum were afterwards introduced, as this was considered to be tbe only metal which could perfectly resist the action of hot and concentrated sulphuric add. Afterwards, however, the enormous expense required for a complete assortment of platinum retorts, induced the attempt to return to the use of iron, and successful experiments were made by M. Toccm, which proved that Iron retorts might be eafely employed, though platinum is still in use in many establishments. - It was found that the very concentration of the acid presented, of itself, an obstacle to the pre-dpitation of the silver or copper by the iron and, further, that the interior surface of the retort acquired a coating of silver, so that the iron and the liquid soon ceased to be in contact. This point has not boon sufifi-. ciently studied but the fact has been placed beyond doubt that the operation succeeds very well In iron vessels, and accordingly, hi many refining establishments, no other are employed. 

Suet and lard form the body of pomades and that the quality of these latter maybe unexceptionable, the fat material must be perfectly flush, inodorous, and pure. The rendered suet being almost always more or loss deficient in those respects, it must, therefore, be subjected to a purifying process, in order to fit it for use in perfumery. This is done by melting the fat by the heat of a saline ot steam bath, in an enamelled iron vessel, and adding to it, gradually, powdered alum and chloride of sodium, in the proportion of one ounce of the former, and two ounces of the latter, to every fifty pounds of fat undsr treatment. 

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