magnetite black
2.a hard gary-black mineral consisting of corundum and either hematite or magnetite; used as an abrasive (especially as a coating on paper).
3.Iron oxide black pigment, magnetite powder for the production of toner, cobalt-modified magnetite powder for magnetic recording were prepared from pyrite cinder. Our study was concentrated on the oxidation precipitation of magnetite, control of size and shape, surface chemical properties of magnetite, surface modification and magnetic properties of cobalt- modified magnetite powder. Using sulfuric acid to leach pyrite cinder, pyrite was used to reduce acid-leaching solution for the first time.
