Technology for extracting rare earth from waste tailings

The invention discloses a technology for extracting rare earth from waste tailings. The method comprises the following steps that allanite ore mixed rare earth ore is ground into ore powder, wherein the granularity of the ore powder is -80 micrometers, batch open-circuit grinding is used first, and then imitation closed-circuit grinding is used; after the selected raw ore is ground for a certain period of time, products with the particle size of -70 micrometers are screened out, and oversize products are ground again, wherein during re-grinding, water needs to be added according to the weightof the oversize products and the grinding density during raw ore grinding; after the content of ore powder with the particle size of -50 micrometers reaches 80% or above, the ore powder is washed withwater; the allanite ore powder is added into a sulfuric acid solution with the concentration of 0.25-0.5 mol/L according to the ratio of the allanite ore powder (kg) to acid (L) being 1:(1-15), the mixture is heated to 40-100