Estabilização "físico-químico" de resíduo sulfetado/sulfatado com incorporação de escória de dessulfuração

Abstract

The process of mining and steel industry are accountable for the movement of millions in the country's economy, on the other hand these actions reponsible for the production of a large volume of solid waste. Associated with these processes, there are new practices geared towards menagement and reuse of these materials. Therefore, the purpose of this research is to assess the physical-chemical behavior of the residue (sterile) coming from a gold mining company when combined with dessulfuration slag, analyzing parameters such as the improvement of the mechanic characteristics of the mixture, capacity of support, the final concentrations of sulfeto/sulfate and permeability. In the preparation process of the samples were used dessulfuration slag in concentrations of 20%, 30% and 40% regarding the mining residue. The best results were attained with 40% of concentration of desulphurisation dreg that allowed 1450% gain in the capacity of support, since the ISC (Índice Suporte Califórnia) of the mining residue was 1,68% after 96 hours of trial and the sample with 40% of dessulfuration slag provided a ISC of 24,37% after 96 hours and a ISC of 63,93% after 28 days. This mixture also provided a reduction in the plasticity and permeability indices of the material, being applicable for paving on back roads. Besides that, when analyzing the sulfeto/sulfate concentrations of the samples collected by the Coluna trial, was verified that the solubilized extracts of samples 1,3, 4 and 5 show concentrations of 9180 mg/L, 1918 mg/L, 2560 mg/L and 3143 mg/L of suphate, respectively, that are above 250mg/L of Sulfate required in NBR 10.004:2004, which allows to classify the residue and mixtures, according to this standard as a Residue No Hazardous and Non-Inert - Class II A, based on Sulfide / Sulphate concentrations. Thereore, after the analysis of the physical-chemical behavior, the sustainable viablity of the incorporation of the two wastes and its application in back roads is verified.