Evaluation of the technical condition of mining processing equipment with planned preventive maintenance at the San Joaquín 2 quarry of Mapeagre Cia. Ltda. CIYA [Internet]. 2025 Mar. 25 [cited 2026 Jun. 4];9(1):30-4. Available from: https://investigacion.utc.edu.ec/index.php/ciya/article/view/1061