Hematite is the mineral form of iron(III) oxide (Fe2O3), one of several iron oxides. Hematite crystallizes in the rhombohedral lattice system, and it has the same crystal structure as ilmenite and corundum. Hematite and ilmenite form a complete solid solution at temperatures above 950 °C (1,740 °F).
Hematite is colored black to steel or silver-gray, brown to reddish brown, or red. It is mined as the main ore of iron. Hematite is the world’s most important ore of iron. Although magnetite contains a higher percentage of iron and is easier to process, hematite is the leading ore because it is more abundant and present in deposits in many parts of the world.
Hematite is a high-density weighting material. The Hematite ore used as a weighting agent in drilling fluids has a mica-like crystal structure ground to a particle size suitable for use in drilling fluids. Hematite is used to obtain mud weights in excess of 20.0 ppg in water based drilling fluids, 19.0 ppg in oil based drilling fluids, or any time that exceptional control is required of solids percentage for rheology control.
Hematite has a specific gravity of >5.05, which is 19% greater than the density of Barite (4.1). Thus, for a given mud weight, a system weighted with Hematite will contain fewer solids by volume. A lower solids concentration will contribute to improved rheological properties, improved penetration rate and decreased overall mud costs.
