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The demand for feldspar as a raw material for various industrial applications continuously increases. Feldspar is a primary raw material in manufacturing ceramics, glass, fillers, welding electrodes, and enamel. Feldspar is often associated with iron oxide, which decreases its economic value and hinders its industrial application. The present work aimed at reducing iron oxide content in Egyptian feldspar ore from the Wadi Zerabi locality. Ball milling was used for preparing feldspar feed of size -250+45µm. Carpco dry high-intensity magnetic separation followed by acid leaching processes were carried out in order to decrease the iron contamination and increase the feldspar content. A Box-Behnken statistical design was used to optimize the magnetic separation results. From a feldspar feed containing 1.40% Fe2O3, a non-magnetic concentrate of 0.25% Fe2O3 was obtained. The Fe2O3 removal reached up to 82% with a high yield as the % weight of non-magnetic feldspar reached up to 97.5%. The leaching process further reduced the iron oxide content down to 0.19 %. Also, the feldspar whiteness was improved from 65.17% in the original ore to 85.60% in the leached product. [ABSTRACT FROM AUTHOR]

Coal plays a major role in the economic development of many countries, especially in metallurgical industries and conventional power generation plants. The removal of sulfur from coal has recently become even more critically important. Existence of sulfur compounds in coal limits its industrial applications due to environmental as well as technical problems. Thus, high sulfur coal is usually upgraded by desulfurization through physical, chemical, and biotechnological processes. In this study, lowering of pyritic sulfur took place after thermal treatment at 500–700°C (pyrolysis) using a wet high-intensity magnetic separation process. The samples were subjected to size reduction to −25 µm and characterized with X-ray diffraction (XRD), proximate and ultimate analysis, and differential thermal analysis (DTA). Then, the experiments were performed based on central composite rotatable design (CCRD) and response surface methodology (RSM) after thermal treatment of coal containing 3.30% total sulfur. Statistical analysis was performed to examine the significance of the effect of different operating parameters. A maximum sulfur rejection of 90.10% with the lowest sulfur content of 0.59 was obtained at 8.38% solid concentration, 4.59 g/min feed rate, and 7810 gauss magnetic field intensity. The confirmation tests at the optimum conditions produced 0.54–0.56% total sulfur with 90.25–92.33% sulfur rejection. [ABSTRACT FROM AUTHOR]