Abstract: There is a waste acid concentration process in the production of titanium dioxide with sulfuric acid process.The waste ferrous sulfate produced from the waste concentrated acid，was neutralized with lime by the most of enterprises.This disposal method not only wasted resources，but also increased treating cost. Introduced a new blending roasting way to fully use the sulfur and iron resources in the waste ferrous sulfate.Remarkable economic results have been achieved，and taking a 100 000 t/a titanium dioxide plant matching 300 000 t/a sulfuric acid as an example，46 900 t pyrite could be saved  annually，yielding 22 920 000 yuan（RMB） of output value.

Key words: waste ferrous sulfate, blending roasting to produce acid, ferrous sulfate monohydrate, ferrous sulfate heptahydrate