الفهرس 
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Abstract
The present study aimed to increase the grade of Egyptian feldspar ore of Wadi Zirib area by increasing the added value of concentrate and reducing impurities of the ore components, and also trying to obtain a commercial grade of feldspar which is suitable for some industrial applications. To use feldspar minerals in different industrial applications, some upgrading processes should be executed to remove these impurities. The first stage of processing was the disposal of slimes fraction (-38 μm) which usually consists of clay minerals. The presence of clay minerals leads to some disadvantages, such as changing the froth stability, increasing pulp viscosity, and overconsumption of reagents in flotation process.
De-sliming processes removed about 30% of iron content into -38 μm fraction. Attrition process was applied after these processes and removed only about 6% of the iron content.
Beneficiation of (-250+38) μm fraction was attempted by applying laboratory scale flotation process method. A collector dosage of 97 g/t of quaternary ammonium solution was the best for mica’s minerals flotation where the percent of Fe2O3 was 13.65% with mass recovery of 0.44% and recovery of 9.84% in mica’s minerals product. The rejected percent of valuable minerals (feldspathic minerals) into floated mica’s minerals didn’t exceed 0.4% with the selected experiment.
Feldspar was separated from the associated minerals by using a two-stage flotation process. Hydrofluoric acid (HF) proved to be the most efficient reagent for separation of feldspar minerals from quartz by flotation. The effect of using HF on the feldspar separation process was studied. laboratory scale flotation experiments were conducted with quaternary ammonium solution as cationic collector for feldspar minerals. Hydrofluoric acid (HF) was used as surface modifier for activation of feldspar minerals and quartz depression, as well. The best concentration of HF was about 2000 g/t. This dosage increased feldspar assay to 85.05% with 67.78% recovery. Overall, a suitable quality feldspar concentrate was obtained with mass recovery of 52.11% having composition of 69.04% SiO2, K2O & Na2O combined about 11.52%, 17.34% Al2O3, 0.4% Fe2O3, and 0.04% TiO2. This product could fulfill the requirements of glass, porcelain, ceramic, vitreous tiles, and semi-vitreous tiles industries.
In order to increase the quality of feldspar concentrate for using in other industries, it is necessary to minimize coloring impurities such as iron and titanium contents. For the removal of coloring minerals from feldspar ore, the most widely used method is magnetic separation process. In this part, it was aimed to reduce the percentages of iron and titanium oxides in feldspar concentrate provided from the best conditions of previous flotation process. The experimental work was conducted to investigate the effect of magnetic field intensity and roll speed on the separation process. Under the best operating conditions, magnetic separation gave a concentrate with mass recovery of 69.24% assaying 0.16% Fe2O3, 0.01% TiO2, and 10.31% sum of K2O & Na2O with recoveries 27.69%, 17.31%, and 61.97%, respectively. The overall mass recovery of this final product was 36.08% of original flotation feed. The best conditions of high intensity magnetic separator, i.e. 16600 Gauss and 24 r.p.m., gave product that could fulfill the requirements of white glaze, nonwhite glaze, and white-ceramic adobe. The percent of removal of Fe2O3 & TiO2 are 72.31% & 82.69% at 16600 Gauss and 65.18% & 76.79% at 24 r.p.m., respectively. These conditions (16600 Gauss & 24 r.p.m.) gave a product that could fulfill the requirements of white glaze, nonwhite glaze, and white-ceramic adobe.