The invention discloses a method for pre-treating
phosphorite of wet process
phosphoric acid by using acidic waste water in the production process of
titanium pigment, which comprises the following steps: (1), collecting the acidic waste water into an acidic waste
water storage groove, controlling the acid degree to be 2 to 5 percent and the total iron concentration to be 0.3 to 0.5 percent; (2), adding the acidic waste water and the milled
phosphorite in a
solid-to-
liquid ratio of 2-5:1 into a reaction groove for reaction; and (3), performing
solid-liquid separation on the
slurry which is obtained in the step (2) to obtain a
solid phase, namely the required
phosphorite. The content of
magnesium in the phosphorite which is treated by the method is reduced by over 70 percent, the loss ratio of the
phosphorus is controlled to be within 1 percent; when the phosphorite which is treated by the process is used for producing the
phosphoric acid by a wet method, the consumption of the
sulfuric acid for mine per
ton is reduced by about 10 percent; and the acidic waste water pretreats phosphorite and then is delivered to a
sewage station for treatment, the consumption of
lime or other alkaline substance is reduced by 60 percent compared with the mode of directly delivering the waste water to the
sewage station, so the economical efficiency of the process is high.