Gemfields (AIM: GEM) announced the first production from its underground mining trial in Zambia. The milestone marks the first step in a transformational innovation for the Zambian emerald mining industry, Gemfields said. The company initiated the underground mining project in February 2009, the trail aims to expand the Kagem mine into areas of high quality emerald production, and enable the mining operation to follow the ore zone efficiently.
"Gemfields is delighted to be involved in what could become an historic achievement in emerald mining in Zambia”, Gemfields Chief Executive Ian Harebottle commented. “While our understanding of the economics of underground mining will develop over the months ahead, today's announcement could ,pave the way for rolling out underground mining methods along the Zambian emerald belts”
The Zambian emerald mining industry has deployed only opencast mining techniques in the past involving high stripping ratios. For example, at the Kagem emerald mine, the stripping ratio typically exceeds 50:1 and approximately 1 gram of emerald and beryl is recovered for every tonne of rock handled. The company believes that underground mining can reduce rock handling requirements and allowing mining operations to follow the ore zone without the need to remove all of the surrounding rock.
The shaft and tunnel system was designed, developed and constructed in-house, and is presently at a depth of 33 metres on dip. After just six months from the first blast, the first production of emerald and beryl gemstones was completed on 10th February 2010.
“If Gemfields' trial underground shaft proves successful, the model could be rolled out to access emerald ore bodies in multiple locations within the Kagem mine”, Harebottle stated. At Kagem several high quality production zones have been abandoned historically, due to the steep incline of the ore zone. These new underground emerald mining methods could enable that these projects become viable again, Gemfields said.
The company’s flagship Kagem mine covers an area of 43 sq km (square kilometres) with the license area hosting six known TMS belts with over 13 km (kilometre) strike length. In its half-year results for the period ended 31st December 2009, Gemfields had US$7.2 million in cash and a gemstone inventory with an estimated value of at least US$9 million.