Evaluación de la desmineralización química de semiantracitas provenientes de minas ubicadas en Boyacá y Santander (Colombia)

Introduction: The non-energy use of coals of high rank (anthracite) has a great potential in industries such as metallurgy and in the synthesis of new carbonaceous materials, however, prior to be used in this application they must be treated for removing impurities or undesirable compounds. Objective: To evaluate the efficiency of the chemical benefit process for the demineralization of anthracites. Method: The chemical characterization of two samples was carried out: Boavita (B) and Capitanejo (C), from mines of Boyaca and Santander, respectively. Removal of ash and mineral matter from samples was evaluated using 5M HCl, 40% HF, and 38% HCl at two different reaction times (45 and 60 minutes) and two particle sizes of the material (250 and 500 μm). Results:  The minimun values reached during the demineralization process for samples B and C, were 0.65 and 0.76% ash (bs) respectively, which were obtained with a particle size of 250 μm and 60 minutes exposure in each of the acids used in this study. Conclusions: The smaller the particle size, the contact surface increases and the degree of demineralization improves, independently of the time of exposure to acids. The efficiency of the chemical benefit shows yields in the reduction of silicates, aluminates and aluminosilicates, of 100%, while for ferrous minerals it is above 50%.