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Vitreous surface reinforcement in low activation granular activated carbon

Abstract:

Activated carbon is used effectively in the mineral gold adsorption process as complex. Its performance essentially depends upon granular hardness, which is required to be greater than 90% in such applications. The lower this value is, the greater the losses of precious metal adsorbed in the fine carbon that remains in cyanide pulps that are discarded. This study evaluated the use of different vitreous materials as a mechanism of surface reinforcement in granular activated carbons of low activation through the determination of the hardness and production yield of the obtained carbon-glass composites. The incorporation of vitreous materials was studied, using sodium metasilicate pentahydrate, recycled glass bottles and commercial enamel frits as glass sources. The studied parameters were the amount, composition and grain size of the glassy loads, and the temperatures and times of thermal treatments. Initially, the low activation carbon presented a hardness of 90.8% and an irregular porous morphology. The obtained composites of activated carbon-glass salts, activated carbon-recycled glass, and activated carbon-glass frits, increased the hardness to values of 98.7; 93.5 and 94.2%; with yields of 66.7; 81.2 and 83.2%, respectively. It was found that the activated carbon-glass frit composite, presented the best hardness-yield of production compromise.