Influência térmica das intrusões ígneas no padrão geoquímico de certos elementos - traço: A (B e As), B (Pb), C (Cd, Hg e Mo), D (Se) e E (F) no carvão das camadas chipanga e bananeiras, na secção 6, da Bacia Carbonífera de Moatize

Abstract

Intrusions can affect coal mineralogically and geochemically, which can lead to enrichment or depletion of some trace elements. (Chen, et tal., 2014) The main objective of this work is to study, through analysis of petrographic and chemical data, the influence of igneous intrusions on the geochemical pattern of coal from the Moatize Coal Basin, specifically in the Bananeiras and Chipanga layers, in Section 6 of the concession of the company VULCAN Mozambique S.A. The igneous intrusions, when coming into contact with the coal, altered its physical and chemical properties, affecting the quality of the resource (type, grade and category), its economic viability and possible environmental impacts. This report is the result of a pre-professional internship carried out at VULCAN Mozambique, as part of the Bachelor's Degree in Applied Geology at Eduardo Mondlane University. The study included several methodological stages, such as a bibliographic review, office work, field activities and laboratory analyses results. A total of 11 boreholes drilled in section 6 in 2018 were analyzed, followed by chemical and petrographic analyses to identify trace elements (As, B, Cd, Hg, Pb, Se, Mo and F). Maps, correlation graphs and geophysical profiles were generated using software such as QGIS, Excel, ArcMap and MiniTab. The results indicated that not all elements were correlated with the proximity of the intrusions, suggesting pre-existing lithological and mineralogical influences. The study contributes to a better understanding of the thermal alteration of coal, allowing less promising areas to be distinguished and supporting the sustainable management of coal mining in Mozambique, considering economic, environmental impacts and academic importance