Bisulfite ammonium

Hair straightening compositions based on mixtures of ammonium bisulfite [10192-30-0] and urea [57-13-6] have been introduced and have found some apphcation in the Caucasian hair market. The reformulation of the cystine cross-links in bisulfite-reduced hair is best accompHshed by a rinse, pH 8—10, rather than by the use of oxidizing agents (66). 

Ammonium bisulfite can be used in place of the sulfur dioxide. The solution is treated with activated carbon and filtered to remove traces of sulfur. Excess ammonia is added and the solution evaporated if the anhydrous crystalline form is desired. The crystals ate dried at low temperature in the presence of ammonia to prevent decomposition (61—63). 

Both batch and continuous processes employ excess sulfur and operate at 85—110°C. Trace amounts of polysulftdes produce a yellow color which iadicates that all the ammonium sulfite has been consumed. Ammonium bisulfite is added to convert the last polysulfide to thiosulfate and the excess ammonia to ammonium sulfite. Concentrations of at least 70% (NH 2S2 3 obtained without evaporation. Excess sulfur is removed by filtration and color is improved with activated carbon treatment or sodium siUcate (66). Upon cooling the aqueous concentrated solution, ammonium thiosulfate crystallines. 

Recovery as liquid sulfur dioxide (absorption of clean dry off-gas in water or chemical absorbtion by ammonium bisulfite or dimethyl aniline),... 

AMMO 2.5 EC , cypermetlu-in, 13 Ammonia, 13 Ammonium acetate, 13 Ammonium arsenate, 13 Ammonium benzoate, 13 Ammonium bicarbonate, 13 Ammonium bifluoride, 14 Ammonium bisulfite, 14 Ammonium carbamate, 14 Ammonium carbonate, 14 Ammonium chloride, 14 Ammonium chlorplatmate, 14 Ammonium clu omate, 14 Ammonium citrate, 14 Ammonium diclu omate, 14 Ammonium fluoride, 14 Ammonium fomiate, 15 Ammonium hexafluorosilicate, 15 Ammonium hydroxide, 15 Ammonium metavanadate, 15 Ammonium molybdate, 15 Ammonium nitrate, 15 Ammonium oxalate, 15 Ammonium perfluorooctanoate, 15 Ammonium persulfate, 15 Ammonium phosphate, 15 Ammonium picrate, 16 Ammonium salicylate, 16... 

At ordinary temperatures, sulfamic acid hydrolyzes slowly forming ammonium bisulfite. However, when heated it hydrolyzes rapidly forming sulfuric acid. Therefore nickel sulfamate should be prepared rapidly before any sulfamic acid hydrolysis occurs due to longer contact time with water. 

Anonymous. Final report on the safety assessment of sodium sulfite, potassium sulfite, ammonium sulfite, sodium bisulfite, ammonium bisulfite, sodium metabisulfite and potassium metabisulfite. Int J Toxicol 2003 22(suppl 2) 63. 

Solutions containing ammonium sulfate, with or without the addition of ammonium hydroxide, have been widely used. The ammonium system can operate effectively only within a pH range of 4.0 to 7.0. As the pH value increases above 7.0, progressively more gaseous ammonia is liberated and this reacts in the gaseous phase with water vapor and SO2 to produce a dense aerosol (white plume) which is difficult for scrubbers to remove. In an ammonia system, in order to regenerate the scrubbing solution, the ammonium bisulfite and sulfite mixture is heated... 

Alternatively, the ammonium bisulfite/sulfite mixture can be treated with calcium hydroxide. Gaseous ammonia is evolved and trapped in water, which is then recirculated to the scrubber. 

In contrast to the highly alkaline (pH 11-13) krafl processes, sulfite pulping processes are acidic in nature and are of two general types (1) the acid sulfite processes utilize caldnm, sodium, magnesium, or ammonium bisulfite in combination with tree or excess sulfur dioxide as... 

The so-called soluble bases now are used, with each having certain advantages. Because solutions of sodium, magnesium, and ammonium bisulfite are all soluble at pH 4.5, the current practice is to pulp at the higher pH, which is usually called bisulfite pulping. Extremely long cooking times (7-10 hr) are necessary with acid sulfite, whereas 4-5 hr is sufficient with bisulfite. 

Ammonia scrubbing is one of many processes for removing sulfur dioxide from flue gases. The gases are bubbled through an aqueous solution of ammonium sulfite, and the SO2 reacts to form ammonium bisulfite ... 

In the presence of aqueous ammonium bisulfite an equilibrium often exists between aromatic amines and aromatic hydroxy compounds. This reaction is called the Bucherer reaction 12 and its mechanism appears to involve the intermediate formation of a bisulfite addition complex. The mechanism which is most widely accepted is that of Fuchs and Stix,13 illustrated here with l-hydroxynaphthalcne-4-sulfonic acid ... 

Ammonia Solutions. It has long been suggested that ammonia solutions age quicker than sodium or potassium solutions of sulfite. We have recorded Raman spectra of three year old 1 M ammonium bisulfite solutions in sealed ampules. These contain not only a solid elemental sulfur phase and solid ammonium sulfate phase, but the liquid phase contains also several percent of dithionate, recognizable by the vibration frequencies of 710 cm- and 1206 cm-, with an intensity ratio of l7io/ -l2Q6 = 3.2. A search for other oxyacids yielded traces of thiosulfate... 

Figure 1. Raman spectra of ammonium bisulfite solution.

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