Ammonium sulfate-sediment acid solution relay leaching process of ion-adsorbed type rare earth ores
The sediment produced by rare earth mining is dissolved by acid to replace some of the leaching agents,aiming to reduce the consumption of ammonium sulfate and lower ammonia nitrogen residue. An ammonium sulfate-sediment acid solution relay leaching process that first injects ammonium sulfate acid solution,then sediment solution,and finally saturated lime water as the tailwater was proposed. The results show that compared with the traditional leaching process,the ammonium concentration in the tailings reduced from 2.053 g to 1.066 g when adopting the relay leaching process with unit consumption of 1.0,the sediment acid solution concentration of 11 mmol/L and dosage of 0.2 times the pore volume;and the leaching rate increases from 47.06％ to 91.68％,an increase of 44.62％,which is comparable to the traditional process with unit consumption of 2.0. The proposed process reduces the use of ammonium sulfate by 50％. After using saturated lime water as the tailwater,more than 94％ of the sediment cations are fixed in the tailings in a colloidal state to prevent secondary pollution caused by the leakage of sediment cations into the environment. The ammonium sulfate-sediment acid solution relay leaching process can reduce ammonia-nitrogen residue and provide a new idea for green mining and efficient exploitation of ion-absorbed type rare earth ores.
ion-absorbed type rare earthammonium sulfatesedimentammonia nitrogen residue
万方数据
维普
