Abstract:Rare earth minerals in potash feldspar tailings are mainly composed of allanite, monazite, bastnaesite and parasite, while niobium minerals in tailings are mainly composed of niobite and rutile, and rare earth and niobium minerals have fine grain size and are closely associated with other minerals. Content of REO and Nb2O5 is 0.52% and 0.19% respectively. Rare earth and niobium were extracted by sulfuric acid roasting-water immersion. Effects of acid addition, roasting time and temperature, leaching temperature and time on leaching rate of rare earth and niobium were studied. The results show that leaching rate of rare earth and niobium is 83.3% and 75.9% respectively under the optimum conditions including mass ratio of sulfuric acid to tailings of 2︰1, roasting at 300 ℃ for 2 h, and leaching at 80 ℃ for 2 h with L/S=3.