Min. Res. details work at Waihi

Press, 29 June 1983, Page 22

Min. Res. details work at Waihi

PA Auckland Developing an open cast mine at Martha Hill, Waihi, will require a construction force of between 350 and 400 for 30 months, say the directors of Mineral Resources (N.Z.) Ltd, in the annual report A staff of 100 would then be employed to operate the mine and a further 60 to 80 to operate the plant. The SBOM to SIOOM capital expenditure would also have a beneficial impact on the economy and create further support jobs. At Martha Hill, the exploration programme completed in September confirmed a resource of 14.6 M tonnes having an average

grade of 3.2 gm of gold a tonne and 32gm of silver within the existing prospecting licence to a depth of about 270 m. These exploration results and satisfactory results from metallurgical testing will enable the joint venture to move into the pre-de-velopment phase, involving mine planning, metallurgical extraction planning, preparation of the preliminary feasibility study, and assembly and collation of basic environmental data, they say. The work related to an application for a mining licence is expected to be completed after April. The preferred option is to

initiate mining by an open pit. This will ultimately measure 700 m by 400 m and be about 140 m deep, the directors say. An open pit would not enable recovery of all the ore resource, some of which would probably be mined later by underground methods. At a cut-off grade of Igm of gold equivalent (which takes into account the value of contained silver) an open pit would enable production of about 8.2 million tonnes of ore and would require removal and storage of 19.2 million tonnes of overburden. An open-pit mining phase would last about 11 years.