Method for recycling and preparing hafnium oxide from hafnium-containing waste material

The invention discloses a method for recycling and preparing hafnium oxide from a hafnium-containing waste material. The method comprises the following steps: 1, adding the hafnium-containing waste material into a mixed liquor of hydrofluoric acid and hydrogen nitrate, and dissolving, so as to obtain a dissolving solution; 2, adding ammonium hydroxide into the dissolving solution, and heating andstirring, so as to obtain precipitation sludge; 3, adopting hydrogen nitrate for dissolving the precipitation sludge to obtain a leaching solution; 4, adopting cation exchange resin for adsorbing theleaching solution to obtain loaded resin; 5, adopting hydrogen nitrate for drip washing the loaded resin to remove impurity elements; 6, adopting sulfuric acid for desorbing hafnium to obtain a hafnium desorption solution; 7, adopting ammonium hydroxide for precipitating the hafnium desorption solution to obtain hydroxide precipitate of hafnium; and 8, heating the hydroxide precipitate of hafniumto obtain hafnium oxide. Ac