ASTM D3724-01(2012)

This specification establishes the properties and requirements for the pigments commercially known as synthetic pure brown iron oxides and its blends, suitable for use in paints and coatings. The pigment, which shall be soft, dry, and finely pulverized, may be manufactured by either of the following methods: precipitation of iron salts; calcination of precipitated iron oxides; blends of synthetic red, yellow, and black iron oxides; and blends of synthetic red, yellow, and black iron oxides plus the addition of carbon black. Specimens shall be suitably sampled and tested, and shall adhere to specified requirements as to total iron oxide, ferrous iron, carbon black, moisture and other volatile matter, organic coloring matter, total sulfates, coarse particles (total residue retained on No. 325 sieve), and water-soluble matter.