Аммония тиосульфата

Химические свойства

Ammonium thiosulfate is a white crystalline solid with an ammonia odor.

Физические свойства

Colorless, monoclinic crystal; hygroscopic; decomposes on heating above 100°C; density 1.679 g/cm₃; very soluble in water (64 g/100 g at 20°C), insoluble in alcohol, and slightly soluble in acetone.

Использование

Ammonium thiosulfate finds application for leaching of gold and silver since it forms strong complexes. It is widely utilized as a photographic fixing agent, which acts quicklier than sodium thiosulfate fixers. It serves as a fertilizer. It acts as an additive to coal-waste mixtures to inhibit the formation of dangerous dioxins and furans. It is used as an analytical reagent in laboratories.

Общее описание

AMMONIUM THIOSULFATE is a white crystalline solid. AMMONIUM THIOSULFATE is very soluble in water. The primary hazard is the threat posed to the environment. Immediate steps should be taken to limit its spread to the environment. AMMONIUM THIOSULFATE is used in photography, in chemical analysis, and for many other uses.

Реакции воздуха и воды

Hygroscopic. Very soluble in water.

Профиль реактивности

AMMONIUM THIOSULFATE is sensitive to heat. AMMONIUM THIOSULFATE is incompatible with magnesium and aluminum powder. Mixtures with sodium chlorate can cause an exothermic reaction which can then decompose explosively. . Reacts with strong oxidizers such as chlorates, nitrates, and nitrites to release toxic ammonia, hydrogen sulfide, and sulfur trioxide gases. Will not polymerize. Ammonia, hydrogen sulfide, and oxides of nitrogen and oxides of sulfur may form in fires [USCG, 1999].

Угроза здоровью

Inhalation of dust may irritate respiratory system. Ingestion could be harmful. Contact with eyes or skin may cause irritation.

Пожароопасность

Special Hazards of Combustion Products: Toxic ammonia, hydrogen sulfide, and oxides of nitrogen and sulfur may form in fires.

Сельскохозяйственное использование

Ammonium thiosulphate, [(NH₄)₂S₂O₃ or ATS] is a crystalline salt, the aqueous solution of which is commonly used as a liquid fertilizer. Crystalline ammonium thiosulphate contains 19% nitrogen and 43 % sulphur and its aqueous solution contains 12% nitrogen and 26 % sulphur.
Ammonium thiosulphate is compatible with nitrogen and nitrogen-potassium solutions, which are neutral or slightly acidic (pH 5.8). It is also used as a suspension: As it is non-corrosive, it can be stored in steel or aluminumdrums.
Ammonium thiosulphate is prepared by the reaction of sulphur dioxide and aqueous ammonia, followed by a further reaction with elemental sulphur.
ATS can be applied directly to soils or as a foliar spray through sprinkler irrigation systems. When applied to soils, ATS decomposes into ammonium sulphate and colloidal sulphur. The ammonium sulphate is available immediately to plants, while the sulphur gets oxidized over a period of time to sulphate ion (SO₄^2-) It is thus available to plants for a longer time. Ammonium thiosulphate also acts as a urease inhibitor. When added to a urea-ammonium nitrate solution, it inhibits urease activity for a month or so. In industry, it is also used as a photographic fixing agent, analytical reagent, fungicide and as a brightener in silverplating baths.

Профиль безопасности

Moderately toxic by ingestion.When heated to decomposition it emits toxic vapors ofNH4^- and SOx.

Возможный контакт

Used as an agricultural chemical and fungicide, metal lubricant; in cleaning metals; in photographic chemicals, making other chemicals. A laboratory reagent.

Перевозки

UN3077 Environmentally hazardous substances, solid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous hazardous material, Technical Name Required.

Несовместимости

Contact with sodium chlorate may cause a violent reaction. Corrodes brass, copper, and copperbased metals.

Утилизация отходов

Incinerate. It may be possible to dispose of waste material at a municipal facility if treated, neutralized and oxidized.