Mechanism Of Ionic Rare Earth Mine Ammonia Wastewater And Suppression Dopant Compound System Leaching

The rare earth ammonia nitrogen wastewater is produced during the rare earth ore dressing and smelting process. There are many ion in it, such as NH4+, RE3+, Al3+, Fe3+, Ca2+, Cl, SiO32-and so on. The has concentration of NH4+concentration is very high, and the pH is between5.4and5.6. There is so much impurity ions in the leaching solution if use it leach rare earth directly. So, in this paper, the composite system of ammomia-nitrogen waste water and QXY-01was used to leach ionic type rare earth ore to achieve the goal of green mine rare earth.Firstly, in this paper, the best conditions of using ammonium sulfate to leach ionic type rare earth ore was determined. And the result was:trickle leaching,3%concentration of ammonium sulfate, leaching agent solution pH value of5.0, the ratio was0.8:1,2.0ml/min flow, leaching column diameter of40mm, the extraction column’s height was13.5cm and the mounted mineral’s density was1.228g/ml. The leaching rate of rare earth was higher than96%.For the leaching speed of ammonia nitrogen wastewater is slower than ammonium sulfate, the main impurity ions influence on leaching speed were studied. And the result showed:the impact was Ca2+>Si032->Al3+>Fe3+, and the permeability under Comprehensive influence was2.242ml/min, compared with ammonium sulfate solution’s permeability, it’s0.003ml/min slowly. Than, verified QXY-01could inhibit impurity ions’leaching but couldn’t influence rare earth leaching rate, and the best inhibition pH value is5.0.The leaching conditions of ammomia-nitrogen waste water and QXY-01composite system leaching rare earth ore was determined.The result showed that when the inhibition pH value was5.0and the concentration of QXY-01was0.35%, The inhibiton of Al3+, Fe3+and Ca2+was90.56%,94.21%and58.48%, and the leaching rate of rare earth was98.87%. In laboratory had done the experiment of different types ionic type rare earth ore leached with ammonia nitrogen wastewater, than precipitated rare earth with ammonium bicarbonate, leaching rare earth with precipitation supernatant fluid at last. And the result showed that rare earth leaching rate were all higher than98%and the inhibition rate of impurity ions were significant.The studied on the kinetics of ammomia-nitrogen waste water and the impurities inhibitions QXY-01composite system leaching ion absorbed rare earth ore showed that rare earth leaching is mainly controlled by internal diffusion, and the apparent activation energy was9.86kJ/mol compared with9.24kJ/mol. At last, differentials means was used to solve kinetic equations of leaching rare earth in this system, and the equationswas:...