Pyrite utilization in the carboniferous region of Santa Catarina, Brazil - Potentials, challenges, and environmental advantages

Abstract

The main coal seams explored in the coal region of Santa Catarina are Barro Branco (BB) and Bonito (BO). Owing to the association with the mineral matter, the tailings generated in the beneficiation are arranged in disposal areas, and subject to the generation of acid mine drainage (AMD). The objective of this study was to evaluate the use of pyrite present in the coal rejects of the BB and BO seams and the environmental gains with desulfurization. For this purpose, densimetric separability test, ash, sulfur, and AMD generation analyses were performed. In addition, the amount of pyritic concentrates and sulfuric acid were estimated considering the current level of production. Three densimetric fractions were obtained: less than 2.2 (energetic material), between 2.2 and 2.7 (low sulfur material), and greater than 2.7 g cm-3 (pyrite concentrate). The results revealed that the two seams could be beneficiated by gravimetric processes, obtaining pyrite concentrates with approximately 60% pyrite. By converting pyrite to sulfuric acid would represent an increase of 500,000 tons per year in the Brazilian production of this material and, in environmental terms, a reduction of up to 90% of the acidity potential to be disposed in the environment in the case of the BB seam and 65% for the BO seam. It was also observed that the "desulfurized" fraction of the BO had higher levels of pyrite and a higher potential for acidity generation than the BB seam, implying greater risks of environmental contamination and higher acid water treatment costs.

Role of the reducing agent in tungsten extraction by chlorination with chlorine from an ore enriched by physical means

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Contaminación Del Agua Y Suelo Por Los Relaves Mineros

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Processing of pyrite derived from coal mining waste by density separation technique using lithium heteropolytungstate (LST)

“…Due to the significant quantity of tailings generated and such significant environmental impacts, the recovery and reuse of this material before its final disposal is essential to reconcile the activity of coal mining with environmentally sustainable development. In terms of environmental impacts, the removal of this material from the tailings can lead to a reduction of up to 90% of the acidity potential to be disposed into the environment, which significantly reduces the chances of generating AMD [7].…”