Method for recovering rare earth and niobium from rare metallic ores

The invention discloses a method for recovering rare earth and niobium from rare metallic ores. The method is characterized by comprising the following steps of: milling raw ores and acidifying and decomposing with concentrated sulfuric acid; leaching with water and performing solid-liquid separation to obtain a leach solution and leach slag; adding water into the leach solution, boiling and performing solid-liquid separation to obtain a hydrolysate and precipitates; magnetically separating the leach slag to obtain magnetic slag and nonmagnetic slag; uniformly mixing the precipitates with themagnetic slag and smelting to obtain niobium/iron alloy and titanium slag; adjusting the pH value of the hydrolysate with ammonia water and performing solid-liquid separation to obtain a neutral solution and neutral slag; and adding oxalic acid to the neutral solution to obtain rare earth oxalate precipitates, and calcining the precipitates to obtain rare earth oxides. The method provided by the invention is suitable for the comprehensive utilization of composite rare metallic ores with coexistence of rare earth, niobium and titanium, can be used for recovering rare earth, niobium and titanium in the ores at the same, directly preparing rare earth oxides, niobium/iron alloy and titanium slag with TiO2 content of above 30% from the composite rare metallic ores, wherein the content of rare-earth oxides is higher than 92% and the total recovery rate of rare earth is higher than 70%. The method provided by the invention is simple and feasible, has low production costs and broad application prospects.