Evaluation of open pit mine design with a focus on the Dichinama marble resource in Western Tigray, Ethiopia

Abstract

The northern region of Ethiopia, particularly the Dichinama locality, holds significant potential for marble resources. Saba Dimension Stone Private Limited Company is currently mining at three key locations in this region: Lidge, Ela-wedizare, and Dugub. However, the company faced challenges with the existing mine layout, which resulted in decreased production capacity. To address this, a comprehensive research initiative was conducted to assess the current mine design and develop a new open-pit layout. The study included geological mapping, rock characterization, sampling, laboratory testing, and geotechnical evaluations, alongside an in-depth analysis of geological formations such as joints, faults, and shear zones. Geotechnical techniques, including rock mass rating (RMR), rock quality designation (RQD), and slope mass rating (SMR), were utilized to inform the development of the new mine design. The findings from the laboratory tests and geotechnical analysis were applied to create a revised mine layout. The new open-pit design has led to significant improvements in production and recovery rates. Specifically, production volumes are projected to increase from 9976 to 12,470 m3 at Ela-wedizare, from 36,150 to 45,187.5 m3 at Lidge, and from 4620 to 5775 m3 at Dugub. Recovery rates are also expected to improve, from 20.5 to 25.6% at Ela-wedizare, from 23.4 to 29.3% at Lidge, and from 35.7 to 44.6% at Dugub. This research underscores the importance of advanced geological and geotechnical approaches in optimizing mining procedures and improving operational efficiency in the Dichinama marble resource region. The implementation of the new design has helped Saba Dimension Stone Private Limited Company overcome prior obstacles, achieving substantial gains in both productivity and recovery.