Aproveitamento da camada de bauxita nodular como minério na mina Alcoa, Juruti - PA

Abstract

The bauxite deposit identified in Juruti-PA is on plateaus Mauari, Guarana, Capiranga and Central is a "blanket", originated during the Pliocene-Pleistocene. Correspond to a laterite horizon that can be divided into three distinct zones: Belterra clay, concretionary laterite zone and the saprolitic zone. In turn, the laterite zone can be subdivided into three subzones: nodular bauxite, laterite and bauxite mass. In Alcoa Juruti Mine just subarea massive bauxite is extractedand utilized as ore. However the chemical analyzes of samples of nodular bauxite layer showed that in some portions of the area currently being explored has the same mass recovery and concentration of alumina and silica allowing its use asore. Furthermore, it has an average thickness and a significant amount of iron introduced is low, it would not cause the decrease of content of alumina, thus reducing the quality of the ore. From the data of holes three drilling campaigns conducted by Alcoa, it was possible the preparation of representative sections to analyze the behavior of nodular bauxite layer, making the evaluation of reserves, and generate isocontent maps alumina, silica and iron, and from the union of these was possible to delimit the area suitable for exploitation nodular bauxite, sometimes discarded.