Ammonium vanadous chloride

The vanadium pentoxide catalyst Is prepared as follows Suspend 5 g. of pure ammonium vanadate in 50 ml. of water and add slowly 7 5 ml. of pure concentrated hydrochloric acid. Allow the reddish-brown, semi-colloidal precipitate to settle (preferably overnight), decant the supernatant solution, and wash the precipitate several times by decantation. Finally, suspend the precipitate in 76 ml. of water and allow it to stand for 3 days. This treatment renders the precipitate granular and easy to 6lter. Filter the precipitate with suction, wash it several times with cold 5 p>er cent, sodium chloride solution to remove hydrochloric acid. Dry the product at 120° for 12 hours, grind it in a mortar to a fine powder, and heat again at 120° for 12 hours. The yield of catalyst is about 3 - 5 g. 

Phthalocyanine 2 can be prepared from 3-phenylphthalic acid (1) and vanadium(III) chloride in the presence of urea and ammonium vanadate at high temperature in a melt.401... 

Anthrapyrimidine and its substituted derivatives are obtained by condensation of 1-aminoanthraquinone (or its derivatives) with formamide or aqueous form-aldehyde/ammonia in the presence of an oxidant, such as ammonium vanadate or m-nitrobenzosulfonic acid. A newly developed, more simple route proceeds via formamidinium chloride, which is prepared from 1-aminoanthraquinone with di-methylformamide and thionyl chloride or phosphorus oxychloride. Cyclization in a solvent in the presence of ammonium acetate affords the desired product ... 

Elemental composition P 43.64%, 0 56.36%. The pentoxide is dissolved in water and the ultimate hydrolysis product, H3PO4, is analyzed for PO4 by ion chromatography. Alternatively, the solution is treated with ammonium molybdate—ammonium vanadate reagent to produce a yellow colored vanado-molybdophosphoric acid. Absorbance or transmittance of the solution may be measured at a wavelength between 400 to 490 nm, depending on. concentration of P04. The solution must be diluted for analysis. The solution may further be reduced with stannous chloride to form an intensely colored molybdenum blue for measuring absorbance or transmittance at 690nm. 

Preparation of Vanadium Oxychloride by Reacting Vanadium(V) Oxide with Thionyl Chloride. Place 16 g of ammonium vanadate into a porcelain crucible. Roast the substance up to a constant mass at 500-550 °C in a crucible furnace, passing oxygen into the latter via a glass tube from a gas meter. 

Ammonium chloride The addition of solid ammonium chloride to a solution of an alkali vanadate results in the separation of colourless, crystalline ammonium vanadate, NH4V03, sparingly soluble in a concentrated solution of ammonium chloride. 

Reduction of ammonium vanadate by HjS gas, in an aqueous solution containing KOH, KCN and hydroxylammonium chloride, yields yellow crystals K4[V(CN)6)(N0)]-H20... 

The nickel and vanadium in the fly ash from the burning of heavy oil can be recovered by chlorination and distillation, with 67% recovery of the nickel and 100% recovery of the vanadium.265 Another method is to leach out the nickel with aqueous ammonium chloride, followed by treatment with hydrogen sulfide to recover nickel sulfide (in 87% yield), which could be refined in the usual way.266 The vanadium was recovered next in 78% yield by solvent extraction with trioctylamine, followed by treatment of the extract with aqueous sodium carbonate to take the vanadium back into water, and finally ammonium chloride to produce ammonium vanadate. 

With sulfuric acid a vanadium hydroxide is precipitated that can be redissolved in soda to a pure soluhon of sodium vanadate. Addition of ammonium chloride precipitates white crystalline ammonium vanadate NH VO. This can be calcined to give orange vanadium pentoxide, suitable for production of pure vanadium and of fer-rovanadium. 

Vanadium usually is recovered from its ores by one of two processes, (1) leaching raw mineral with hot dilute sulfuric acid, and (2) roasting ore with common salt to convert vanadium into water soluble sodium vanadates. In the sulfuric acid leaching process, vanadium is extracted from acid leach liquors by solvent extraction with an aliphatic amine or an alkyl phosphoric acid in kerosene. The organic solvent extract then is treated with an aqueous solution of ammonia in the presence of ammonium chloride to convert vanadium into ammonium metavanadate. Alternatively, the organic extract is treated with dilute sulfuric acid or an aqueous solution of soda ash under controlled conditions of pH. Vanadium is precipitated from this solution as a red cake of sodium polyvanadate. 

Salts of Vanadic Acid. Pour 3-4 ml of a sodium vanadate solution into each of two test tubes. Add to one of them a silver nitrate solution, and to the other a saturated ammonium chloride solution. Write the equations of the reactions. 

The gravimetric estimation of vanadium in alkaline vanadate solutions has also been effected by precipitating as ammonium metavanadate in the presence of ammonium chloride.6 Precipitation is incomplete, however, unless the solution is quite saturated with ammonium chloride 7 the addition of alcohol is recommended.8 Other gravimetric processes which have been investigated include the precipitation of barium pyrovanadate,9 precipitation of silver metavanadate,10 precipitation of manganese pyrovanadate,11 and the use of cupferron.12... 

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