Impact of coal density on heavy equipment efficiency in mining operations: A case study of silicified and low rank coal. BIS Energy and Engineering, [S. l.], v. 3, p. V326025, 2026. DOI: 10.31603/biseeng.563. Disponível em: https://unimma.press/conference/index.php/biseeng/article/view/563. Acesso em: 31 may. 2026.