Study On Process Mineralogy And Niobium Beneficiation From Bayan Obo East Aegirine-type Ore

Niobium is an important rare metal with good physical and chemical properties,high melting point,high boiling point,high ductility and high corrosion resistance,etc.It is an important raw material in high-tech field.With the rapid development of China's economy,the level of science and technology has been significantly improved,and the use of Niobium resources has become more and more extensive.In the current Sino-US trade situation,niobium resources as an important strategic metal,status is self-evident.In China,there are abundant niobium resources in Bayan Obo,but it is difficult to develop niobium resources due to the characteristics of complex ore types,many mineral types,wide distribution,low grade and fine grain size,so far it has not been effectively utilized.Taking the typical aegirine ore of Bayan Obo East Mine as the research object,the process mineralogy and the beneficiation technology of niobium resources were studied.The results of process mineralogy show that the grade of iron(TFe),rare earth(REO)and niobium(Nb₂O₅)in the raw ore is 18.72%,8.2%and 0.1%;The contents of harmful elements phosphorus,sulfur and fluorine were 0.78%,0.56%and 5.25%.The distribution rate of niobium element in niobium minerals is pyrochlore 46.89%,ilmenorutile 11.46%,fergusonite 5.89%,aeschynite 4.57%,niobite 3.91%,baotite 2.35%,and other minerals24.93%.The particle size distribution of niobium minerals:the content of pyrochlore less than 20?m is 62.06%,the content of ilmenorutile less than 20?m is 60.76%,the content of aeschynite less than 10?m is 72.64%,the content of niobite less than 10?m is 62.93%,and the content of baotite less than 20?m is 73.99%.The particle size of niobium mineral is fine,and fine grinding is needed in the process of mineral separation.Niobium minerals are closely related to iron minerals,rare earth minerals,aegirine,amphibole and calcite.In the early stage,iron and rare earth are removed to reduce the influence on niobium separation effect.Under the condition of grinding fineness of-74?m 90%and magnetic field intensity of 0.2 T,iron was removed by one roughing,and the final iron(TFe)grade in iron tailings was 12.03%.Rare earth was removed from iron tailings by one roughing process under the conditions of silicate inhibitor 1.6 kg/t,collector P₈1.1 kg/t,foaming agent 2^#oil 0.15 kg/t,flotation temperature 65?,pulp concentration 50%and flotation time 5 min,and the final rare earth(REO)grade of rare earth tailings was 2.01%.Experimental study on niobium flotation,under the optimal conditions of grinding fineness is-37?m 92%,pulp concentration of 60%,flotation temperature of 60?,activating agent Ys-1 dosage of 1.6 kg/t,collector BJ-1 dosage of 2.4 kg/t,flotation time of4 min,coarse niobium concentrate with grade of 0.27%and recovery of 80.77%was obtained.The grade of niobium(Nb₂O₅)is 1.09%and the recovery is 51.29%through the open and closed circuit test of one coarse and three fine particles.The analysis of tailings shows that under the condition of fine grinding particle size,some aeschynite in the tailings has been dissociated,but the particle size is fine and has not been recovered.In the tailings,pyrochlore and aegirine are connected or wrapped by aegirine,baotite and aegirine are connected,ilmenorutile and albiite are connected.These fine monomer niobium minerals and the niobium minerals associated with gangue were not collected,leading to a low recovery rate.