Method for removing fluorine in bastnaesite sulfuric acid leaching liquid by aluminiferous adsorbing agent

The invention belongs to the technical field of rare earth wet metallurgy and specifically relates to a method for removing fluorine in a bastnaesite sulfuric acid leaching liquid by an aluminiferous adsorbing agent. The method includes roasting aluminum hydroxide for 2-6 hours at the temperature of 450 DEG C to 600 DEG C to prepare an activated aluminum oxide aluminiferous adsorbing agent, diluting the bastnaesite sulfuric acid leaching liquid for 10-100 times, adjusting the acidity in 0.1-1.0 mol*L-1, adding the aluminiferous adsorbing agent with the addition amount of 0.5-10g/50ml, oscillating for 10-60minutes, performing solid-liquid separation to obtain aluminiferous adsorbing agent solids loaded with fluorine and a defluorination sulfuric acid leaching liquid. By means of the method, fluorine-containing three wastes are reduced by removing fluorine, the pollution to the environment caused by the processes is greatly reduced, and simultaneously, the sulfuric acid leaching liquid before extraction is subjected to fluorine removal, so that the effect of the fluorine on the following extraction and separation of the rare earth can be eliminated. Besides, the adsorbing agent which is used for absorbing can be recycled, and the cost is greatly reduced.