Nitrate organic phase

Conditions Aqueous phase - 2.0 to 6.0 grams of IT per 100 cc of solution containing aluminum nitrate. Organic phase - solvent represented by curve. Eqtial phase volumes equilibrated at 27°C. 

Particles are the major cause of the ha2e and the brown color that is often associated with smog. The three most important types of particles produced in smog are composed of organics, sulfates, and nitrates. Organic particles are formed when large VOC molecules, especially aromatics and cycHc alkenes, react with each other and form condensable products. Sulfate particles are formed by a series of reactions initiated by the attack of OH on SO2 in the gas phase or by Hquid-phase reactions. Nitrate particles are formed by... 

Centrifugal separators are used in many modem processes to rapidly separate the hydrocarbon and used acid phases. Rapid separation greatly reduces the amounts of nitrated materials in the plant at any given time. After an explosion in a TNT plant (16), decanters (or gravity separators) were replaced with centrifugal separators. In addition, rapid separation allows the hydrocarbon phase to be quickly processed for removal of the dissolved nitric acid, NO, etc. These dissolved materials lead to undesired side reactions. The organic phase generally contains some unreacted hydrocarbons in addition to the nitrated product. 

The distribution of highly extractable solutes such as and Pu between the aqueous and organic phases is strongly dependent upon the nitrate anion concentration in the aqueous phase. This salting effect permits extraction or reextraction (stripping) of the solute by controlling the nitric acid concentration in the aqueous phase. The distribution coefficient, D, of the solute is expressed as... 

Ce(IV) extracts more readily iato organic solvents than do the trivalent Ln(III) ions providing a route to 99% and higher purity cerium compounds. Any Ce(III) content of mixed lanthanide aqueous systems can be oxidi2ed to Ce(IV) and the resultiag solutioa, eg, of nitrates, contacted with an organic extractant such as tributyl phosphate dissolved in kerosene. The Ce(IV) preferentially transfers into the organic phase. In a separate step the cerium can be recovered by reduction to Ce(III) followed by extraction back into the aqueous phase. Cerium is then precipitated and calcined to produce the oxide. 

To a stirred solution of 5.70g (21.1 mmol) of 4,4.5,5-tetramethyl-2[(5)-(A)-3-(trimethylsilyloxy)-l-bulenyl]-l, 3,2-dioxaborolane in 130 mL of petroleum ether (bp 40-60 C) are added ca. 20 mg of cobalt(II) nitrate hexahydrale followed immediately by 2.75 g (23.1 mmol) of freshly distilled thionyl chloride. Slow evolution of sulfur dioxide ceases after 4h. The mixture is then filtered and concentrated in vacuo at r.t. to give crude 15, which is taken up in 50 mL of petroleum ether and washed with 30-mL portions of buffer (pH 5) until the pH is constant. 100 mL of brine are added to the organic phase and the pH is adjusted to 7 by addition of sat. aq NaHCO,. The pH should not exceed 7, otherwise decomposition ensues. The phases are separated and the organic phase is dried with MgS04 and concentrated at r.t. to give 15 yield 4.39 g (96%) Contact of 15 with metal surfaces should be avoided. 

The selectivity issue has been related to multi-phase processing [31]. Nitrations include both organic and aqueous phases. Oxidation to phenol as one side reaction takes places in the organic phase, whereas all other reactions occur in the aqueous phase and are limited by organic solubility. For this reason, enhancing mass transfer by large specific interfaces is a key to affecting product selectivity. 

Figure 4.51 Liquid/liquid two-phase plug-flow with plugs of nitrating agent (dark) and organic phase (white) in a capillary micro reactor [94].

OS 31] [R 16c] ]P 23] The levels of dinitrobenzene, dinitrophenol and picric acid in the organic phase during benzene nitration in a micro reactor were monitored [31]. Picric acid levels were no higher than 100 ppm for all experiments conducted. Dinitrobenzene was the largest impurity fraction. A study revealed contents < 1000 ppm up to 34 mass-% on increasing the sulfuric acid content from 70 to 85%. 

Chhatre et al. (1993) have reported that highly selective ort/io-nitration of phenol with dilute nitric acid can be realized by using a microemulsion medium. It seems that in the microemulsion medium, phenol orients in such a way that the phenyl group remains extended towards the side of the organic phase, whereas the hydroxyl group protrudes in the aqueous... 

Picolinamide 22 could be isolated in 87% yield by crystallization from aqueous i-PrOH, which also resulted in an ee upgrade from 92% to 99.3%. Deprotection of the N-Boc group was performed by dissolving 22 in 5 M aqueous HC1. It was found that the subsequent N-acetylation of the revealed amine could be performed in the same pot under Schotten-Baumann conditions by simply adding 10M aqueous NaOH and Ac20. After extraction with CH2C12, the organic phase was concentrated and used in the nitration step without any further purification. 

Ammonium nitrate undergoes phase changes at 32° and 83°C and melts at 170°. It is not normally considered an explosive when pure, although under suitable conditions it can be made to detonate. When mixed with small amounts of organic matter it becomes much more sensitive and several serious explosions have occurred with such mixtures. The limit of organic matter so far allowed in the U.K. is 0-05%, but in some countries 0 1% is accepted. 

A diverse range of neutral organic molecules has been used to stabilize or to enhance the solubilities of neutral metal-containing entities in an organic phase. Some examples of commercial significance are listed in Table 6. When used alone they efficiently transport metal salts across a circuit. An example is the use of tributyl phosphate (TBP) in recovery of uranyl nitrate,... 

Displacement by cyanide works particularly well, and many other nucleophilic substitution reactions are enhanced by PTC. Most monovalent anions can be transferred, including alkoxides, phenoxides, thiocyanates, nitrates, nitrites, superoxides and all of the halides. Divalent anions are usually too hydrophilic to be transferred into the organic phase. 

A. Crowson, R.W. Hiley, T. Ingham, T. Mccreedy, A.J. Pilgrim, A. Townshend, Investigation into the detection of nitrated organic compounds and explosives by direct chemiluminescent emission during thermally induced gas phase decomposition reactions , Anal. Commun. 34 (1997) 213-216. 

In an investigation of the extraction of trivalent actinides, An(III) from 0.01 M nitric acid solutions of various LiNOj concentrations into o-xylene containing the tertiary amine salt trilaurylmethylammonium nitrate, TLMA HNOj, Van Ooyen [29] found that the amine was monomeric only at very low concentrations (<0.1M in the organic phase) but at higher concentration formed both dimers and trimers. 

Although silver is not treated by solvent extraction in any of the flow sheets, silver is recovered from aqueous solution in several other situations. For these processes, Cytec developed reagents with donor sulfur atoms to extract this soft element. For example, tri-isobutylphosphine sulfide (CYANEX 47IX) extracts silver from chloride, nitrate, or sulfate media selectively from copper, lead, and zinc [32]. The silver is recovered from the loaded organic phase by stripping with sodium thiosulfate, and the metal recovered by cementation or electrolysis. Silver can also be extracted from chloride solution by a dithiophosphinic acid (CYANEX 301) [33]. 

The leach liquor is first treated with a DEHPA solution to extract the heavy lanthanides, leaving the light elements in the raffinate. The loaded reagent is then stripped first with l.Smoldm nitric acid to remove the elements from neodymium to terbium, followed by 6moldm acid to separate yttrium and remaining heavy elements. Ytterbium and lutetium are only partially removed hence, a final strip with stronger acid, as mentioned earlier, or with 10% alkali is required before organic phase recycle. The main product from this flow sheet was yttrium, and the yttrium nitrate product was further extracted with a quaternary amine to produce a 99.999% product. 

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