Extraction with liquid ammonia

Sodium chlorite [7758-19-2] M 90.4, m 180°(dec). Crystd from hot water and stored in a cool place. Has also been crystd from MeOH by counter-current extraction with liquid ammonia [Curti and Locchi Anal Chem 29 534 1957]. Major impurity is chloride ion can be recrystallised from O.OOIM NaOH. 

Ozone forms red-brown potassium ozonide, KO3, by reacting with dry potassium hydroxide. Ozonide is obtained by passing oxygen-ozone mixture containing 6 to 8% ozone over dry KOH at -10 to -15°C for several hours, followed by extraction with liquid ammonia at -60°C. Evaporation of the red solution forms red-brown needles of KO3. 

Arsenic Pentasulphide, As2S5.—When arsenic is fused with an excess of sulphur the product contains arsenic, sulphur and arsenic pentasulphide the last-named may be extracted with liquid ammonia 8 or, by careful fractionation, the arsenic and sulphur may be removed, leaving the sulphide. If the elements are fused together in stoichiometric proportions, a greenish-yellow plastic mass is obtained which gradually hardens and becomes lemon-yellow if this product is powdered and digested with aqueous ammonia, a yellow solution results and insoluble sulphur remains. After filtering, the addition of an acid to the yellow solution precipitates the pentasulphide. 

To eliminate the high pressure resulting from the excessive water, we studied the use of dried SWL solids in several experiments. It was never possible completely to recover pasting oil when the dried solids were used. At 380°C. the paste oil was nearly recovered, but the monophenol yield was low. At 428°C., the paste oil recovery was lower, and the monophenol yield was higher. In one experiment the dried solids were extracted with liquid ammonia so that carbohydrate material would be removed from the calcium lignin sulfonate. Approximately 10% of the solids were removed... 

One extraction process used industrially on a large scale is the purification of sodium hydroxide for use in the manufacture of rayon. The sodium hydroxide produced by electrolysis typically contains 1% sodium chloride and 0.1% sodium chlorate as impurities. If a concentrated aqueous solution of sodium hydroxide is extracted with liquid ammonia, the NaCl and NaClOs are partitioned into the ammonia phase in preference over the aqueous phase. The heavier aqueous phase is added to the top of an extraction vessel filled with ammonia, and equilibrium is reached as droplets of it settle through the ammonia phase to the bottom. This procedure reduces impurity concentrations in the sodium hydroxide solution to about 0.08% NaCl and 0.0002% NaClOj. 

Dilution with HCOC/H COj buffer addition of known amount of Cr(III)- Cr(Vl) enriched spike extraction with liquid anion exchange solution (Amberlite LA-2/M1BK) back-extraction of Cr(Vl) with ammonia solution electrodeposition on Pt wire in ammonia solution detection by IDMS of masses 52 and 53 (Lab. 11)... 

Fig. 70. Wash tube for extraction with liquid ammonia.

After ammonolysis, ammonia is evaporated and can be reused after liquefaction, while degradation products of polyurethane hard segments (e.g., amines and chain extenders) and urea are removed by extraction. The pure polyol is left in the reactor. It can be removed mechanically or by extraction with liquid ammonia in which it is soluble. The recovered amines can be converted to the corresponding isocyanates and can be reused, along with polyols, in the same applications as before. A flow scheme of the recycling process is shown in Figure 6.9. 

Caustic soda solution, produced in the diaphragm process, is not qualified for many applications, especially in chemical industry, due to its relatively high salt content of 1 wt% NaCI. A further purification by extraction with liquid ammonia is possible but expensive. 

For cephaeline. Acidify the aqueous liquids from the assay for emetine with dilute hydrochloric acid, make just alkaline with ammonia, extract with chloroform and proceed as in the assay for emetine. Weigh the residue as cephaeline. 

To remove chlorate and other salts, the 50 percent diaphragm cell caustic may be extracted with liquid ammonia in a pressurized system. The ammonia fraction then is processed through a stripper to remove and recycle the ammonia. The alkaline stripper bottoms are useful in neutralizing acidic waste streams. The purified caustic is evaporated further, and then fed to an anhydrous concentrator, typically an Inconel falling film evaporator, heated with molten salt. The anhydrous caustic, containing at least 97.5 percent NaOH, is marketed as one solid mass in drums, as flake caustic, or more desirably as beads or prills. The last are marketed in bulk or bags. 

To a vigorously stirred suspension of 2 mol of lithium amide in 2 1 of liquid atimonia (see II, Exp. 11) was added in 15 min 1 mol of propargyl alcohol (commercial product, distilled in a partial vacuum before use). Subsequently, 1 mol of butyl bromide was added dropwise in 75 min. After an additional 1.5 h, stirring was stopped and the ammonia was allovied to evaporate. To the solid residue were added 500 ml of ice-water. After the solid mass had dissolved, six extractions with diethyl ether were performed. The (unwashed) combined extracts were dried over magnesium sulfate and then concentrated in a water-pump vacuum. Distillation of the residue through a 40-cm Vigreux column afforded 2-heptyn-l-ol, b.p. 

To a solution of 22 g of K0-tert.-Ci,H9 (see Exp. 4, note 2) in 400 ml of anhydrous liquid ammonia were added 22 g of the bis-ether (note 1). After stirring for 4 h, 20 g of powdered ammonium chloride were introduced in small portions. The ammonia was removed by placing the flask in a water-bath at 40°C, then 200 ml of water were added and five extractions with small portions of redistilled pentane were carried out. The combined extracts were washed with water, dried over magnesium sulfate and then concentrated in a water-pump vacuum. The residue was carefully distilled through a 40-cm Vigreux column, giving the allenic bis-ether,... 

Hove 1. The procedure described in Ref. 1 was modified. To a solution of 2.0 mol of lithium acetylide in 1.2 1 of liquid ammonia in a 4-1 round-bottomed, three-necked flask (see Fig. 2) was added 1.5 mol of freshly distilled benzaldehyde with cooling at about -45°C. After an additional 30 min finely powdered ammonium chloride (2 mol) was introduced in 15 min. The ammonia was allowed to evaporate, then water (1.1 1) was added and the product was extracted with diethyl ether. After drying over magnesium sulfate the extract was concentrated in a water-pump vacuum. High-vacuum distillation,... 

Supercritical fluid solvents have been tested for reactive extractions of liquid and gaseous fuels from heavy oils, coal, oil shale, and biomass. In some cases the solvent participates in the reactions, as in the hydrolysis of coal and heavy oils with water. Related applications include conversion of cellulose to glucose in water, dehgnincation of wood with ammonia, and liquefaction of lignin in water. 

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