Uses
The nonahydrate and other hydrated aluminum nitrates have many applications. These salts are used to produce alumina for preparation of insulating papers, in cathode tube heating elements, and on transformer core laminates. The hydrated salts are also used for extraction of actinide elements.
Preparation
The nonahydrate is prepared by treating aluminum, aluminum hydroxide,
aluminum oxide, or aluminous mineral with nitric acid. The nitrate is crystallized from the solution.
Reactions
Since Al(NO3)3 or its salt hydrates dissociates to Al3+ and NO3– ions in the aqueous solution, its reactions in solutions are those of Al3+ . It is partially hydrolyzed, producing H3O+ and thus accounting for the acidity of its solution in water. The products constitute a complex mixture of mono- and polynuclear hydroxo species. Aluminum nitrate is soluble in bases, forming aluminates, [Al(OH)4(H2O)2]–. It decomposes to Al2O3 when heated at elevated temperatures.
Chemical Properties
Aluminium nitrate nonahydrate is white crystalline powder
Uses
Aluminium nitrate nonahydrate is used in metal standard solutions; extraction of uranium.
Uses
It finds use in tanning leather, antiperspirant, corrosion protection, extraction of uranium, nitrating agent. It is an effective dopant for producing highly conductive thin film by utilizing the sol gel method.
Purification Methods
Crystallise the nitrate from dilute HNO3, and dry it by passing dry nitrogen through the crystals for several hours at 40o. After 2 recrystallisations of ACS grade, it had S, Na and Fe at 2.2, 0.01 and 0.02 ppm, respectively.
