Based on the positive economics of the PFS, work started in April 2012 to support the Study; this work included drilling for metallurgical samples on the Emba Derho deposit as well as geotechnical drilling near the proposed Emba Derho pit and at proposed plant facilities.
Variations to the Prefeasibility Study Plan
As in the PFS, the Study is considering a centralized process plant near the large Emba Derho deposit using flotation for the recovery of the base metals. However, in order to enhance economics and reduce project capital cost requirements, various processing trade-off studies have shown that early selective mining and shipping of the DSO from the Debarwa deposit to a smelter as well as early heap-leaching of the known zones of gold mineralization on the project are feasible and result in the optimum economic scenario.
Direct Shipping Ore (DSO)The DSO Zone is located within the supergene copper zone of the Debarwa deposit and contains 116kt of high grade material at an average grade of 16% copper, 3.0g/t gold and 77.0g/t silver. The DSO zone is located about 40 meters below the surface and is approximately 140 meters long. The Study will include a plan to begin mining operations on the Asmara Project by mining, crushing and direct shipping the DSO material from Debarwa, which is located about 45km south of the Emba Derho plant site. The extraction of DSO material early in the project life could provide early cash flow and reduce initial capital exposure. The DSO material will be crushed to minus ¾ inch and transported to the port of Massawa for shipping and sale to smelters. This plan for earlier production was outlined in the feasibility study for a standalone operation at Debarwa (see news release dated May 14, 2012) however it was not included in the mining plan outlined in the PFS because additional metallurgical work was required at that time.