Ammonium Sulfite

Chemical Properties

Ammonium sulfite is a colorless to yellow crystalline (sand-like or sugar-like) solid, normally sold or used in a 40% solution. It is used both as a reducing agent and in photography. This compound is a salt that can form from the reaction of ammonia and sulfur dioxide or hydrogen sulfide. This product is frequently found in the overhead of crude distillation units and can be quite corrosive to steel equipment. Chemical corrosion inhibitors are often used to control corrosion from ammonium sulfite and other ammonium salts.

Physical properties

Colorless monoclinic crystals. Soluble in water, its aqueous solution is alkaline. Slightly soluble in alcohol. Insoluble in acetone and carbon disulfide. It is easily oxidized to ammonium sulfate in air. It can be decomposed into ammonia and sulfur dioxide when heated.

Uses

Ammonium Sulfite is an additive used in the production of caramel.

Preparation

In the ATS process, sulfur dioxide is absorbed from incinerated Claus tail gas in aqueous ammonia to produce ammonium sulfite and ammonium bisulfite in solution.

Definition

ChEBI: Diammonium sulfite is a p-block molecular entity and a sulfite salt.

General Description

AMMONIUM SULFITE is a colorless crystalline solid. The primary hazard is the threat to the environment. Immediate steps should be taken to limit its spread to the environment. AMMONIUM SULFITE is used in the manufacture of other chemicals, in medicine, and photography.

Air & Water Reactions

Soluble in water.

Reactivity Profile

AMMONIUM SULFITE is a reducing agent. Emits toxic sulfur dioxide and oxides of nitrogen when heated to decomposition [USCG, 1999].

Health Hazard

Inhalation of dust causes irritation of nose and throat. Ingestion causes irritation of mouth and stomach. Dust irritates eyes.

Fire Hazard

Special Hazards of Combustion Products: Toxic sulfur dioxide and oxides of nitrogen may form in fires.

Potential Exposure

Ammonium sulfite is used in medicines, metal lubricants; explosives, photography, hair wave solutions; and to make other chemicals. It is also used as a preservative, and for treating agricultural grain.

Shipping

UN2693 Bisulfites, inorganic, aqueous solutions, n.o.s., Hazard class: 8; Labels: 8-Corrosive material. UN3077 Environmentally hazardous substances, solid, n.o. s., Hazard class: 9; Labels: 9-Miscellaneous hazardous material, Technical Name Required.

Incompatibilities

A strong reducing agent. Reacts violently with strong oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides.

Waste Disposal

Dissolve or mix the material with a combustible solvent and burn in a chemical incinerator equipped with an afterburner and scrubber. All federal,state, and local environmental regulations must be observed. May be buried in a chemical waste landfill in accordance with federal, state, and local statutes; or, if oxidized and neutralized, it may be sent to a municipal sewage treatment plant for biological treatment Incineration.

Raw materials

Preparation Products