Biolixiviação: uma rota biotecnológica para extração da scheelita

Abstract

Bacterial leaching, also known as bioleaching, has now been widely applied by the mineralmetallurgical industry to treat various ores as well as to recover metals and tailings. This technological route may be an alternative to the processing of scheelite tailings. The objective of this study was to evaluate the application of a biotechnological route for the solubilization of scheelite from pure samples and water from Brejuí mine located in Currais Novos-RN. The Scheelite samples were submitted to the 250 ml Erlenmeyer bioleaching tests, subjected to contact and temperature control in a Shaker incubator. Stirring was kept constant in all runs at 120 rpm. The behavior of the sheelite solubilization was analyzed in of mine water solution with initial pH ranging between 2-5. The pH was corrected with sulfuric acid solution. The leachates were filtered and the filter material subjected into a muffle at 700°C for 50 minutes. The leached samples were collected for bacteriological analysis in Petri dish, to verify the bacterial growth. The results show that there is a growth solubilization for the contact time studied (120 h) for all pH ranges studied, as well as the bacteriological growth was not stabilized. In this phase of the work, a 12% solubilization result was obtained. However, as the microorganisms were not identified and the extraction curves were increasing, it is advisable try to increase the contact time to maximize the leaching results.