Method for preparing aluminium fluoride by utilizing low grade bauxite

The invention provides a method for preparing aluminium fluoride by utilizing low grade bauxite. The method mainly comprises the following steps: hydrochloric acid leaching to remove iron, stirring and ball kneading, high-temperature roasting to remove silicon, ultrasonic hydrofluoric acid washing and concentrated sulfuric acid washing to remove titanium. The method has the beneficial effects that the problem of how to effectively remove the impurities in the low grade bauxite, such as iron, silicon and titanium, to prepare fine aluminium fluoride is solved through the steps, so that the active ingredients in the low grade bauxite are fully utilized, thus improving the product quality and reducing the resource waste; and the method provided by the invention dispenses with pretreatment of the low grade bauxite, is mild in process conditions and is suitable for large-scale production.