Separation and recovery of scandium and titanium from red mud leaching liquor through a neutralization precipitation-acid leaching approach

Selective recovery of scandium and titanium from red mud leaching solution was achieved through neutralization precipitation followed by acid leaching approach. In the neutralization precipitation section, the effects of pH, temperature and reaction time on metal precipitation efficiency were investigated. Under the optimal condition, the precipitation efficiencies of scandium and titanium were 93.74% and 99.47%, respectively. In the acid leaching section, the effects of acidity, temperature, reaction time, and raffinate to acid solution ratio on leaching efficiency were investigated. Under the optimal condition, the leaching efficiencies of scandium and titanium were 99.97% and 5.44%, respectively. The loss of scandium and titanium were 6.3% and 5.9%, respectively. Compared with the traditional extraction procedure of scandium in red mud, this method could separate titanium from scandium effectively, which is beneficial for the purification of the products and improvement of value of the metal. A new approach was proposed to separate and recover Sc and Ti from red mud, and separation of Sc and Ti was remarkable by this method with low scandium loss. • A new approach was proposed to separate and recover Sc and Ti from red mud. • Adsorption co-precipitation of Sc with Ti was verified. • Separation of Sc and Ti was remarkable by this method with low scandium loss. • Sc and Ti can be easily recovered after separation.