Biogenic iron oxides have been collected from a water stream and subsequently magnetically modified using water-based magnetic fluid. Both natural and magnetically modified materials have been characterized in detail using wavelength dispersive X-ray fluorescence spectrometry, X-ray powder diffraction, Mössbauer spectroscopy, electron microscopy and BET surface area measurements. The natural material is composed of 2-line ferrihydrite, forming hollow microtubules-sheaths of Leptothrix ochracea, and detrital components. As a result of the ferrofluid modification, maghemite nanoparticles were identified on the surface of the treated material. The active surface area of the bulk, magnetically-modified sample was 148 m2 g-1. The magnetically modified material was tested as inexpensive magnetically responsive adsorbent for the removal of selected organic xenobiotics, namely organic dyes, from aqueous solutions. The observed maximum adsorption capacities ranged between 34.3 and 97.8 mg of dye per 1 g of adsorbent.

The introduction of high-entropy material has provided the possibility of efficiently producing low-cost advanced materials with several unique properties suitable for industries. High-entropy materials have gained significant interest because they can be tailored to have functional properties. Among the highentropy material are the high entropy oxides. The objective of this study was to synthesize (Mg0. 2Ti0. 2Zn0. 2Cu0. 2Fe0. 2)3 O4 high entropy oxides (HEO) using different iron sources of Fe2 O3, Fe3 O4, and Fe2 O3 /Fe3 O4 mixture and to study their structure and magnetic properties. Solid state synthesis method was used to obtain (Mg0. 2Ti0. 2Zn0. 2Cu0. 2Fe0. 2)3 O4 using low-cost raw materials and different iron sources. The XRD diffraction patterns along with the Rietveld analysis indicated that for the three iron source(s), a pure single-phase Fd3̅m spinel structure was obtained after the heat treatment at 1000 ℃ for 24 hours. The SEM images and elemental MAP analysis indicated that the powders were agglomerated with semispherical morphology and the constituent elements were uniformly distributed. Magnetic test results obtained from the VSM test revealed that the magnetic properties are severely influenced by the iron source used for the synthesis of the (Mg0. 2Ti0. 2Zn0. 2Cu0. 2Fe0. 2)3 O4 HEO samples. The HEO samples obtained using the Fe3 O4 sample had better magnetic properties (Ms= 13. 93, Mr= 4. 39, and Hc=350) compared to the other two samples.

Steelmaking slag of Mobarakeh Steel Company (MSC) has a high iron content which makes it unsuitable for conventional slag recovery; as in cement industries. On the other hand, EAF slag in this company is almost free of zinc because of using more than 90 percent DRI in the charge. Therefore, removal or recovery of iron from the slag can be a suitable solution to slag recovery in this company. In this research work, cold bonded briquette was made from mixtures of milled slag and coke breeze. The effect of binder content on the strength of the briquettes was studied. The reduction of iron oxides was also investigated by heating up the briquettes in a muffle furnace. The results indicated that using 4wt% sodium silicate as binder leads to reasonable compression strength of about 1500kg although the strength could be increased to as high as 2000kg by using 6wt% binder. Up to 40% reduction, the reducing rate was almost high; then it decreased and reached a minimum value at 70% reduction. Using extra carbon than the reaction stoichiometry didn’t have significant effect on the reduction. Temperatures above 1000oC up to 1200oC had also a small positive effect on the reduction rate. When reduction was performed at 1000oC, for 180min, semi-reduced material (70% reduced) could be obtained, which can be used (cold or hot) in BOF or other steelmaking processes.