| Questions And Answer | Back Directory | [Description]
The trilithium orthophosphate (lithium phosphate, Li3P04 ) and lithium dihydrogen orthophosphate, LiH2P04 , are formed in equilibrium with aqueous solutions of proper composition. However, the dilithium salt does not exist in equilibrium with solution at normal temperatures.
Lithium phosphate may be prepared by the reaction of lithium hydroxide and phosphoric acid followed by evaporation of the solution. Lithium dihydrogen phosphate, LiH2P04 ,may be formed by the reaction of a proper stoichiometric ratio of lithium hydroxide or lithium carbonate with phosphoric acid. The solution is evaporated to yield lithium dihydrogen phosphate which is purified by recrystallization. Lithium dihydrogen phosphate can be dehydrated thermally.
The pyrophosphate and the metaphosphate are formed successively. The lithium phosphates formed by pyrolytic processes tend to be glassy solids. The lithium phosphates do not form hydrates as do the other alkali metal phosphates.
A process for the conversion of propylene oxide to allyl alcohol at 230-270°C using lithium orthophosphate as a catalyst has been patented. A mixture of lithium orthophosphate and vanadium pentoxide may be used in the catalytic oxidation of unsaturated hydrocarbons to dicarboxylic acid anhydrides.
|
|
|