Research On Sodium Roasting-Acid Leaching Decomposition Of Rare Polymetallic Concentrate

In this paper,rare polymetallic concentrate as the research object,put forward the technical route of sodium roasting acid leaching decomposition,which can efficiently recover valuable elements in minerals,and achieve efficient and clean metallurgical method.Firstly,the process mineralogy of rare polymetallic concentrate is analyzed,and the mineral parameters such as mineral types,chemical composition,dissemination characteristics and mineral particle size are analyzed.The results show that the proportion of zircon in rare polymetallic concentrate is 59.18%,and it contains 10.18%Fe₂O₃,Si O₂ and other associated resources.The mineral particle size of the mineral is generally fine,and the particle size is generally concentrated in 20-38?m Zircon is associated with other gangue minerals to some extent,and the zirconium content of monomer is about 40%.The reaction of rare polymetallic concentrate at different roasting temperature and solid alkali ratio was studied.The results showed that:when the rare polymetallic concentrate was roasted with Na OH as additive,Zr Si O₄ in the mineral was decomposed into Na₄Si O₄ and Na₂Zr O₃.The analysis of XRD,SEM,EDS,ICP-OES and FT-IR showed that when the roasting temperature was 800?,Zr Si O₄ in the mineral was decomposed into Na₄Si O₄ and Na₂Zr O₃,When the ratio of solid to alkali is 0.75:1,the decomposition of Zr Si O₄ in the roasted ore is the most thorough,and the yields of Na₄Si O₄ and Na₂Zr O₃are the highest,which proves that the reaction is the most thorough under this condition,which is the optimal reaction condition.Leaching experiments of roasted ore were carried out to explore the optimal leaching rate of Zr through different leaching conditions.The experimental results show that the optimal leaching conditions are as follows:leaching time 20 min,liquid-solid ratio 5 ml/g,leaching temperature 60?,hydrochloric acid concentration 4 mol/L,and the leaching rate of Zr can reach 98.1%.According to the experimental results of acid leaching kinetics of roasted ore,the leaching process of Zr element conforms to the nuclear shrinkage model within the leaching temperature range.The leaching reaction of Zr element with hydrochloric acid is controlled by chemical reaction,and the apparent activation energy of leaching reaction is 83.91 k J/mol.Mn,Fe and Ti in the roasted ore are basically leached into the leaching solution to realize the comprehensive recovery of valuable elements.Nb in the roasted ore is not leached and enters into the slag phase.Because the rare earth elements in the roasted ore do not reach the optimal leaching conditions,a small part of them are not leached into the slag phase.