Abstract: During the production of titanium dioxide by sulfuric acid method, by-products containing a large amount of iron resources, such as ferrous sulfate heptahydrate slag and waste acid, are generated, For every 1.0 ton of titanium dioxide produced, approximately 5.0 m³ of free sulfuric acid and 4.0 ton of by-product ferrous sulfate are produced. The iron resources in these two types of waste have high utilization value. Currently, a mere fraction of the ferrous sulfate heptahydrate slag has undergone comprehensive repurposing, while the majority languishes in storage. Meanwhile, the waste acid is primarily used for lime neutralization, a procedure that not only results in the squandering of significant iron resources but also poses a substantial environmental risk. Based on the total amount of titanium dioxide resources and their distribution characteristics in the sulfuric acid process, this work clarifies that the utilization of iron-based resources is the bottleneck to restricting its clean production, and proposes a method for using iron resources in ilmenite to prepare battery-grade iron phosphate and iron-based pigments. With the new idea, the high-value utilization of titanium dioxide waste acid and by-product ferrous sulfate slag can be achieved, and its feasibility has been systematically analyzed.