Release and Influence Mechanism of Magnesium Sulfate and Ammonium Sulfate Leaching on the Ionic Adsorption Rare Earth and Heavy Metals
Traditional ammonium sulfate and new magnesium sulfate are the main leaching agents for in-situ leaching of ion-adsorption rare earth ores.In addition to paying attention to the leaching efficiency of rare earths,whether the leaching process of rare earth will cause the release of associated heavy metals and affect the groundwater environment is worthy of attention.Therefore,taking the Longnan rare earth mine in Jiangxi province as the research object,the effects of pH,solid-liquid ratio and leaching agent concentration on the release and change of rare earth and metal ions such as Pb,Mn and Cd were studied,under the condition of magnesium sulfate and ammonium sulfate as leaching agent.The results showed that the leaching rate of rare earth and heavy metals were greatly affected by pH,followed by the solid-liquid ratio and leaching agent concentration.The effect of pH on the release of metals in the leaching solution was Pb＞Mn＞Cd.The results of microscopic characterization showed that the phase composition of the main minerals in the rare earth ore did not change significantly before and after leaching,and the heavy metals such as Mn and Fe on the surface of kaolinite and potassium feldspar entered the leaching solution through ion exchange.On the whole,ammonium sulfate had a more significant effect on the release and migration of RE3+than magnesium sulfate,which may aggravate the release of heavy metal ions in ore and cause excessive heavy metals in groundwater.
万方数据
维普
