拜耳法赤泥熔融态深度还原烧结协同提取铝、铁实验研究

赤泥中铁、铝的存在影响钪和稀土的浸出及萃取。通过对拜耳法赤泥进行分析测试，设计了还原烧结协同回收铝、铁技术方案，系统研究了熔融态深度还原烧结协同提取赤泥中铝、铁的工艺。在较佳条件下，铁精矿品位为73.97%，回收率达到90.27%，铝溶出率达到96.28%，铝硅酸盐矿物转化为铝酸钠，碱浸得到铝酸钠溶液，后续可用于制取聚合氯化铝产品。赤泥中的含铁复杂矿物转化成具有磁性的磁铁矿和单质铁，磁选回收含铁矿物，实现赤泥中铁、铝的协同回收。该工艺不仅减弱了铝、铁矿物对后续酸浸萃取提取钪、钛、稀土的不利影响，且使得钛、钪和稀土在尾渣中得到富集，有利于实现赤泥多元素高值化综合利用。 

Experimental Study on Extraction of Aluminum and Iron from Bayer Red Mud by Deep Reduction Sintering

The presence of iron and aluminum in the red mud affect the leaching and extraction of scandium and rare earths. Through the analysis and testing of the Bayer process red mud, a technical plan for the reduction and sintering to recover aluminum and iron was designed, and the process of the molten deep reduction and sintering to extract aluminum and iron from the red mud was systematically studied. Under the optimum conditions, the grade of iron concentrate is 73.97%, the recovery rate is 90.27%, and the dissolution rate of aluminum is 96.28%, the aluminosilicate mineral is converted into sodium aluminate, and the sodium aluminate solution is obtained by alkali leaching, which can be used to prepare polyaluminum chloride products in the subsequent. The iron-containing complex minerals in the red mud are transformed into magnetic magnetite and elemental iron, and the iron-containing minerals are recovered by magnetic separation to realize the coordinated recovery of iron and aluminum in the red mud. The process not only weakens the adverse effect of aluminum and iron ore on the subsequent extraction of scandium, titanium and rare earth by acid leaching, but also enriches titanium, scandium and rare earth in the tailings, which is conducive to the realization of multi-element comprehensive utilization of red mud.