Small Hematite Nanoparticles from the Kiruna-Type Ore; Evaluation of Declined Balance Limit of the Attrition Process and Their Catalytic Properties.

Hematite nanoparticles possess unique properties which have motivated substantial attention for numerous applications, including environmental remediation and wastewater treatment as a promising novel technology. The magnetite-silicate raw material of Kiruna-type ore has been introduced as an innovative precursor, decreasing the attrition balance limit for large-scale production of the ball-mill-derived hematite nanoparticles below the critical size. In this study, the hypothesis and the postulated role of quartz in the effective size reduction process were further investigated. The prepared samples were characterized in detail via X-ray fluorescence (XRF) and powder X-ray diffractometry (pXRD) to be compared with the previous results. Furthermore, the catalytic and photocatalytic activities of the obtained nanoparticles were evaluated in the oxidation reaction of a common persistent sulfo-organic contaminant. The results exposed outstanding reactivity, particularly in their photocatalytic performance, suggesting them as a strong oxidizing agent and active photocatalyst, which greatly promises many possible applications including water and environmental remediation.