The mixture of chromite ore concentrate from El-Baramiya region and soda ash with and without lime was briquetted and roasted at different temperatures (900-1100 deg C), in a flow of air. The yield of Na_2CrO_4 (chromic oxide recovery in water solution) can be achieved to maximum value when Cr_2O_4: Na_2CO_3 = 1 : 2.5 mole ratio (in absence of CaO), while the maximum recovery of chromic oxide in water can be achieved when Cr_2O_4 : Na_2CO_3 : CaO = 1 : 2.5 : 2.5 mole ratio. The briquetting process affectes on the amount of chromic oxide recovery. Also the controlling mechanism for both processes of roasting (with or without calcium oxide), are controlled firstly (20percent recovery) by chemical reaction, while in the meddle and final stage is controlled by solid diffusion mechanism.
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