Magnetite

Magnetite (Fe3O4, black iron oxide, magnetic iron ore, black iron sand) is an important ore of iron. This mineral is of scientific and industrial interest because of its special magnetic properties.

Uses
It has many uses, incl. as a catalyst in the Fischer_Tropsch process that converts syngas to liquid fuels. Other applications are as pigment, in polishing compounds, medicines, magnetic inks, the automotive industry, light metals casting, civil engineering, the chemical industry, heat storage, powder metallurgy, a functional polymer filler and in a compounded form for use by the moulder, Also in these industries: Acoustic/Noise, Agriculture, Ballast, Brick/Refractory, Catalysts, Cement, Ceramic, Coal, Coloring, Construction, Counterweights, Drilling, Energy, Heavy Weight Aggregate, Mineral Processing, Plastic, Powder Metallurgy, Radiation Shielding, Smeltering and Water Treatment

Source: your nearest beach or river


Product Ecology

 * most important use is as a source of iron. Can be reduced to metallic iron using the DRI process: http://opensourceecology.org/wiki/Direct_Reduced_Iron_%28DRI%29
 * (unreduced iron oxide): catalyst in Fischer-Tropsch process for biofuels
 * (unreduced iron oxide): iron fertilization in iron-deficient soils

Preparation of nanoparticles
Simple recipe for the production of magnetite nanoparticles.  (This is from Wikipedia - please feel free to replace with more extensive recipe).

Magnetite particles can be prepared in the laboratory as a ferrofluid in the Massart method by mixing iron(II) chloride and iron(III) chloride in the presence of sodium hydroxide.[10]

Magnetite also can be prepared by chemical co-precipitation, which consist in a mixture of a solution 0.1 M of FeCl3·6H2O and FeCl2·4H2O with mechanic agitation of about 2000 rpm. The molar ratio of FeCl3:FeCl2 can be 2:1; heating this solution at 70 °C, and immediately the speed is elevated to 7500 rpm and adding quickly a solution of NH4OH (10 volume %), immediately a dark precipitate will be formed, which consists of nanoparticles of magnetite.