THERMAL-DECOMPOSITION OF AMMONIUM FLUOROFERRATES 2-LESS-THAN-OR-EQUAL-TO-X-LESS-THAN-OR-EQUAL-TO-3)

Different ammonium fluoroferrates (NH4)(x)FeF2x (2 less than or equal to x less than or equal to 3) have been investigated. The thermal deco mposition of the compounds obtained can be interpreted by their identi cal crystal structures (cryolite type). The decomposition products of all ammonium fluoroferrates formed in initial stage are isostructural of NH4FeF4. The decomposition is accompanied by the partial reduction of Fe(III) to Fe(II) by ammonium isolated. The end product of the ther mal decomposition is FeF2 and FeF3 mixture.