The coal-bearing strata of the Morungava coalfield (RS, Brazil): Petrographic, chemistry and technological characterization of coal seams from borehole CBM 001-MORS

Abstract

Considering the need to expand the national energy matrix, it is imperative to develop studies on unexplored coal deposits (eg Morungava Reservoir), where further research dates back to the 1980s. The mineral source is located in the northeast of Rio Grande do Sul South, occupying an area of 250 km2. In order to evaluate the potential of the coal deposit (CBM-001-MO-RS) and its economicity, the petrographic, chemical and technological characterization of the layers obtained (a total of six), with a depth of 387.70 m, Coal of 9.22 m. A total of 27 samples were used to determine the following parameters: charcoal lithotypes, vitrinite reflectance, maceral counts, immediate analyzes higher calorific value, total sulfur, X-ray diffraction and processing test. The lithotype of frosted coal predominates in the samples, with a rank ranging from high bituminous coal volatile A to anthracite. The distinct layers present progressive underwater volcanic intrusion. The vitrinite maceral group predominates in the coals in the lower portion, while the intinite predominates in the upper one. Mineral matter tends to present increases from the base to the top. The coals presented high levels of ash (> 50% mbs), volatile matter (6.04-30.69% mbs), sulfur (0.20-2.88% mbs) and higher calorific value (777-4,732 Kcal / Kg). There is mineralogical predominance of quartz, kaolinite, and illite. Many of the layers are classified as carbonaceous rock (> 50% gray / b.s.). The beneficiation tests indicated low yield (<7% vol.) in obtaining noble products.><7% vol.) in obtaining noble products.