Fabrication of a Nanosize Hematite Pigment via Waste Ferrous Sulfate Recycling Using Sulfur Reduction

Nanometer-sized hematite was prepared via a two-step process. In the first step, FeSO4 center dot 7H(2)O was oxidized to Fe-2(SO4)(3) by oxygen in an acidic solution. In the second step, the Fe-2(SO4)(3) was reduced to nanosize hematite with sulfur vapor at 550 degrees C. The hematite has good thermal stability up to 500 degrees C and good colloid stability in water-based paint. Its properties satisfy the requirements of the international standard ISO 1248-A-I-1-a for an iron oxide red pigment.

Automated summary

Nanometer-sized hematite was synthesized via a two-step process, involving the oxidation of FeSO4·7H2O to Fe2(SO4)3 by oxygen in an acidic solution and the reduction of Fe2(SO4)3 to nanoscale hematite using sulfur vapor at 550°C. The resultant hematite exhibited good thermal stability up to 500°C and colloid stability in water-based paint, meeting the requirements of the international standard ISO 1248-A-I-1-a for an iron oxide red pigment.