The De Bron-Merriespruit (DBM) Project is the result of the consolidation of Wits Gold’s original De Bron area with the unmined southern portion of the Merriespruit mine, which was acquired from the Harmony Group.
It is Wits Gold’s most advanced project, with an Indicated Resource estimate of 34.5Mt at 5.3g/t (5.9Moz), and an Inferred Resource estimate of 25.0Mt at 5.2g/t (4.2Moz). By comparison with other Witwatersrand projects on similar tabular reefs, DBM has been densely drilled, with the completion of 88 boreholes over a 15km² area.
DBM comprises a triangular block measuring some 22km², located between the main Welkom goldfield to the north and the Beatrix and Joel mines to the south. Within the project area, four gold bearing conglomerates are developed. These consist of the Beatrix, Kalkoenkrans, B and Leader Reefs, all of which occur at the relatively shallow depths of between 480m and 1 250m below surface. The higher-grade Kalkoenkrans Reef will be targeted primarily.
DBM – South Africa’s next shallow gold mine
An independent scoping study* completed by Turgis Consultants in June 2011 indicated that the optimal mine design for DBM was a shallow underground design, comprising a 700m vertical shaft served by a 12 degree conveyor decline. The preliminary production model is based on footwall haulages, cross-cuts to reef at 150m intervals, conventional breast stoping by hand held rock drills and scraper winches. The conveyor decline will be used for rock transport to surface and the complementary vertical shaft will be used for men and materials. Once at surface, mined ore will be fed into a purpose carbon in leach (CIL) plant for crushing, milling and gold recovery. The scoping study is available on this website and at www.sedar.com.
Production is planned at 135 000oz/year with cash costs of $569/oz. A 25-year Life of Mine has been modeled and first production is on schedule to begin in 2016.
Pre-feasibility and environmental studies are currently in progress and will be completed in the first half of 2012. These will be followed by a definitive feasibility study, anticipated to be completed by mid-2013.
The results of a recent 11 borehole pre-feasibility drilling programme are expected to convert a portion of the shallow Inferred Resources into the Indicated category, which is expected to translate into positive updates to the DBM financial model. A revised Resource Estimate is expected in early 2012.
*The independent scoping study is compliant with Canada’s NI43-101 regulation. It was undertaken with the participation of Snowden Mining Industry Consultants and was based on an Indicated Resource of 34.5Mt at 5.3g/t Au (5.9Moz) that occurs in the same reefs as an Indicated Resource of 17.0Mt at 0.16kg/t U3O8 (6.1Mlbs).