الفهرس 
Chapter 1 : IntroductionOnly 14 pages are availabe for public view
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Abstract
The present study is devoted to investigate the possibility of preparing potassium chromate from Egyptian low-grade chromite ore (38.20 % Cf203) by the conventional method of oxidation roasting. Samples of high-grade limestone, clay and white sand deposits were used in this work. As the Egyptian chromite ore is characterized by its low Cr203 and CrlF e ratio, and high serpentine, a trial was made at the end of this study to beneficiate the chromite concentrate applying the same technique of the roasting process.
Samples of raw materials used in this study are low-grade chromite ore taken from EI-Baramyia region, Eastern Desert, and high-grade limestone from Beni-Khalid and local sand each from west Samalom City, as well as clay from Gabal EI-Mohasham East Beni-Mazar City, EI-Minia, Egypt.
Technological samples of these ores were prepared and investigated by means of mineralogical, chemical, thermal, x - ray diffraction analysis. These studies reveal that the main minerals constituting chromite ore are chromite, pichrochromite, serpentine and calcite, whereas the chromite concentrates containing high values of pichrochromite with small serpentine and no calcite minerals. Calcite is the main structure of limestone deposit. Clay is low-grade and composed mainly of montmorillonite, kaolinite and illite as clay minerals with quartz as nonnclay mineral.
Chromite ore sample (I) contains 38.20 % Cr203, 9.06 % FeO, 5.55 % Fe203, 18.25 % Ah03, 21.00 % MgO, 7.19 % Si02 and 4.08 % CaO.