Magnetic properties of ilmenite used for oxygen carrier aided combustion

Oxygen carrier aided combustion is a process that utilizes oxygen carrying particles in fluidized bed to transport from oxygen-rich oxygen-poor regions the reactor. A commonly used oxygen-carrying material ilmenite (FeTiO3) which naturally occurring mineral. At higher partial pressures can react pseudobrookite (Fe2TiO5) and thereby take up oxygen. Upon reduction of oxygen-lean locations released, enhances distribution through Ilmenite was as an industrial 115 MWth circulating (CFB) boiler where recycled waste wood chips were utilized fuel. Bottom ash samples extracted after one two weeks separated into fractions by magnetic separator. The fraction expected be enriched iron-containing oxides therefore aimed recirculated boiler. SEM-EDS analysis revealed non-magnetic consists largest extent feldspar (KAlSi3O8) particles. significant amount freshly introduced also classified Characteristic for these lack layer, suggesting they had only recently been added system. In fraction, several found covered layer rich Ca, Fe, Ti, Si. Comparing XRD prior separation with its decrease peaks corresponding feldspar. removal further corroborated XRF analysis, concentration K, Al Si significantly however, no changes observed Fe. present analyses shows prolonged exposure time increases susceptibility. Non-magnetic shown acquire susceptibility formation surface containing Fe-rich attrition products ilmenite.