Method for preparing ferrous nitrate and lead sulfate by waste acid generated by preparing titanium white powder with sulfuric acid method

The invention provides a method for preparing ferrous nitrate and lead sulfate by waste acid generated by preparing titanium white powder with a sulfuric acid method. The method for preparing the ferrous nitrate and the lead sulfate comprises the steps of: mixing and reacting waste acid generated by preparing titanium white powder with the sulfuric acid method with excessive ferrous hydroxide to generate ferrous sulfate; filtering reaction solution to obtain filter liquor which mainly contains ferrous sulfate; adding excessive lead nitrate into the filter liquor which mainly contains the ferrous sulfate to react, generating ferrous nitrate and lead sulfate, filtering the reaction solution, and separating the ferrous nitrate from the lead sulfate solution; washing, drying and smashing the lead sulfate precipitate to obtain a lead sulfate product; and adding a small amount of ferrous sulfate into the ferrous nitrate solution to neutralize the lead nitrate, transmitting a reactant into apressure-reducing distill