The invention discloses a method for recycling a
metal oxide from a waste
flue gas denitration catalyst, comprising the following steps of: crushing the waste
flue gas denitration catalyst to carry out pre-
roasting pretreatment at high temperature; adding Na2CO3 into the waste
flue gas denitration catalyst according to the proportion, mixing, pulverizing and
roasting at high temperature to obtain a
sintering block; crushing the
sintering block and putting the crushed
sintering block into hot water, and stirring and lixiviating to obtain
titanate; adding sulphuric acid into the
titanate, filtering, water-washing and
roasting to obtain TiO2; adding the sulphuric acid into the lixiviated filtering liquid to regulate a pH value to 8.0-9.0; adding excessive NH4Cl for
vanadium precipitation; decomposing NH4VO3 obtained from filtering at high temperature to prepare a V2O5 product; adding
hydrochloric acid into the filtering liquid subjected to the
vanadium precipitation to regulate a pH value to 4.5-5.0; adding CaCl2 for
molybdenum and
tungsten precipitation; treating the
CaM0O4 and CaWO4, obtained from filtering, with the
hydrochloric acid and roasting to obtain MoO3 and WO3. The method of the invention has the advantages of simple process and apparatus, high recycling efficiency, good product technical data, large treatment capacity and the like.