机械活化镍铁尾矿的酸浸工艺研究

分别使用中国XQM-21、俄罗斯AGO-Ⅱ行星球磨机对镍铁尾矿进行机械活化,通过X-射线衍射仪、透射电子显微镜等分析测试手段,研究了机械活化前后镍铁尾矿的晶型、形貌、粒度的变化,考察了机械活化前后镍铁尾矿的酸浸工艺条件。结果表明,镍铁尾矿主要物相为镁橄榄石和磁铁矿,活化后结晶程度降低,晶格缺陷变大,颗粒变细,分散性更好。在盐酸浓度6mol/L、固液比1∶6、酸浸时间120m in、温度95℃条件下,机械活化镍铁尾矿中的氧化镁浸出率最高。

Study on the Effect of Mechanical Activation on Acid Leaching of Magnesia from a Ni-Fe Slag

The Ni-Fe slag was activated by mechanical methods using planetary ball mills(XQM-2L and AGO-Ⅱ).X-ray diffraction(XRD)and transmission electron microscope(TEM),etc.were used to characterize the slag.The effects of mechanical activation on the variation of crystal forms,appearances,granularity and leaching rate were examined.The results indicate that the main phase of the Ni-Fe slag is forsterite(Mg2SO4)and magnetite(Fe3O4).After mechanical activation,the crystalline-degree of the Ni-Fe slag is decreased,the crystalline latter defects are expanded,the grain size of particles is fined and the dispersibility is so much the better for leaching process.The leaching rate of magnesia(MgO) is the highest under following technological conditions:hydrochloric acid concentration 6mol/L,ratio of solid to liquid 1∶6,the leaching time 120min and the leaching temperature 95℃.