RESUMOO presente trabalho busca simular a atividade preg--robbing da matriz carbonosa de minérios auríferos a partir de carvões minerais de diferentes níveis de maturação (antracito, betuminoso e lignito), a fim de avaliar a aplicabilidade e a funcionalidade de oito aditivos químicos em desativar/passivar a matéria carbonosa responsável por adsorver o ouro solubilizado. ). Avaliou--se também o efeito da variação do tempo de condicionamento (5, 30 e 120 min.) na supressão do poder adsorvente do carvão. Para os aditivos C3 e Qe o incremento no tempo de condicionamento de 5 para 120 min. foi acompanhado de um aumento na supressão da adsorção de 10% e 20%, respectivamente.
PALAVRAS--CHAVE:Ouro, preg--robbing, condicionamento, aditivos químicos.
REDUCTION OF PREG--ROBBING ACTIVITY OF CARBONACEOUS GOLD ORES WITH THE UTILIZATION OF CHEMICAL ADDITIVES ABSTRACTThe present work aims to simulate the preg--robbing activity of the carbonaceous matrix of gold ores through different types of mineral coals (anthracite, bituminous and lignite), in order to evaluate the applicability and functionality of eight chemical additives in deactivating/passivate the carbonaceous matter responsible for adsorbing the solubilized gold. Adsorption tests showed that, unlike anthracite coal, bituminous coal and lignite were not able to adsorb gold in any extent, so anthracite coal was selected for deactivation/passivation assays. In these tests, aliquots of anthracite coal were conditioned for 120 min. in solutions containing the additive in concentrations ranging from 10 to 500 mg. ). The effect of the conditioning time (5, 30 and 120 min.) on suppression of the adsorbent power of the coal was also evaluated. For additives C3 and Qe the increase in the conditioning time from 5 to 120 min. was accompanied by an increase in the suppression of the adsorption of 10% and 20%, respectively.