Chemical Properties
white solid
Uses
Reagent for determination of fluorine, thoriated
tungsten filaments.
Preparation
The phosphates are dissolved in cone, hydrochloric acid and precipitated with oxalic acid, and the thoroughly washed precipitate is extracted with warm aqueous Na2CO3. Most of the rare earths stay in the residue, while the thorium dissolves in the form of a carbonate complex, Na6Th(CO3)5. The material is freed of the remaining traces of rare earths by repeated crystallization in the form of the sulfate Th(SO4)28H2O. The procedure consists of precipitation of the hydroxide with ammonia and solution of the latter in sulfuric acid to re-form the sulfate. The precipitate from the last purification stage is dissolved in nitric acid to yield the nitrate.
General Description
A white crystalline mass. Mildly toxic. Not combustible but accelerates burning of combustible materials. May explode in a fire if in large quantities or if the combustible material is finely divided. Toxic oxides of nitrogen are produced in fires. Mildly radioactive. Radioactive materials emit certain rays detectable only by instruments. Minimal radiation hazard in transport. No protective shielding for packages is required.
Air & Water Reactions
Somewhat soluble in water.
Reactivity Profile
Thorium nitrate is soluble in water and very soluble in alcohol (ethanol) and acids and is not combustible but accelerates burning of combustible materials. Thorium nitrate is highly reactive and incompatible with combustible materials, organic materials, and finely powdered metals. It may explode in a fire if in large quantities or if the combustible material is finely divided. Toxic oxides of nitrogen are produced in fires. Thorium nitrate, on contact with oxidising agent, oxidisable materials, and combustible and/or organic materials, causes fire and chemical hazards and violent explosion.
Mixtures of metal/nonmetal nitrates with alkyl esters may explode, owing to the formation of alkyl nitrates; mixtures a nitrate with phosphorus, tin (II) chloride. or other reducing agents may react explosively [Bretherick 1979 p. 108-109]. With water forms a weak solution of nitric acid, the reaction is not hazardous.
Hazard
Dangerous fire and explosion risk in contact
with organic materials, strong oxidizing agent.
Radioactive.
Health Hazard
Compound has low chemical toxicity, but alpha emission is expected to constitute a hazard if a fairly large amount is inhaled or ingested. Dust may irritate eyes and cause diffuse dermatitis. Beta and gamma emission is small.
Safety Profile
Poison by
intraperitoneal, intravenous, and
intratracheal routes. Moderately toxic by
ingestion. Experimental reproductive
effects. Radioactive. An oxidizing material;
when in contact with readily combustible
substances will cause violent combustion or
ignition. When heated to decomposition it
emits toxic fumes of NOx. See also
THORIUM and NITRATES.
