Sierra Leone’s largest diamond-mining company, Koidu Holdings, says it has secured funding for the $150-million expansion at the Koidu kimberlite project and implementation is gaining momentum.
CEO Jan Joubert reports that the expansion project incorporates all the currently evaluated kimberlite resources on the property. The richer K1 pipe, which was mined by vertical pit methods between 2005 and 2007, is currently being redeveloped to be brought back into production by the end of this year.
Once the new 180 t/h processing plant is commissioned in early 2012, the company will ramp up production from both the K1 and K2 openpits to over 500 000 ct/y. “Optimisation studies indicated that the two openpits would be economic to depths of 310 m for K1 and 240 m for K2. At average mining rates of 100 000 t/m of ore and 1.4-million tons a month of waste, the openpit phase of the expansion project will continue until the end of 2015. The underground operation will be ramped up as early as 2015, drawing ore from the two kimberlite pipes, as well as from the four small blows developed along two of the four kimberlite dyke zones included in the mine plan at present,” he says.
Joubert adds that the currently defined, indi- cated and inferred resource, signed off by independent competent persons and diamond specialist, Mineral Services Canada, amounts to over 14-million metric tons at respectable grades. An additional 3.7-million metric tons of kimberlite was drilled and has been classified as geological potential, to be upgraded into the resource statement in the next phase of resource extension and evaluation.
“The company’s resource base and mine plan will carry the mine through to 2026 but, with both kimberlite pipes being open ended at depth, the company intends to increase the resource base substantially to extend the life-of-mine beyond the planned 15-year period.” The feasibility study for the expansion project was driven by South African-founded SRK Consulting, a firm of consulting engineers and scientists, which was primarily responsible for the mine design, geotechnical analyses, reserve estimation and financial modelling.
“Development of the main decline will start in mid-2012 to have the underground infrastructure in place by 2014. Blast hole open stoping is the mining method selected for the K1 and K2 orebodies, with no crown pillar left in situ between the openpit and underground opera- tions. Mechanised longhole stoping will be used for mining the kimberlite dyke zones,” explains Joubert. He says that the scale of the expansion project will increase the company’s workforce from 778 permanent employees, the majority of whom (90.4%) are local Sierra Leoneans, to over 1 330 by 2016.
“The number of local contractors assisting in the construction of infrastructure and the community resettlement programme is presently 478, with 283 dedicated to the resettlement project alone,” he says.
He adds that the impact of this project on the local community and economy is huge.
“The company is currently one of the largest contributors to government revenues in terms of taxes, royalties and contributions to development programmes. Scaling up by a factor of five, the company expects its annual payments to government and the local community to increase accordingly,” he says.
Considerable attention has been paid to the impacts the company’s expanded operations will inevitably have on the environment and nearby communities. South African environmental agency Digby Wells Environmental, in association with local Sierra Leonean company Cemmats Group, was appointed to assess the impacts associated with the increased scale of operations.
“The high level of detail now required for these types of studies, according to the Equator Principles, World Bank and International Finance Corporation guidelines, is designed to protect all stakeholders and mitigate any negative impacts identified,” says Joubert.
The full environmental and social impact assessment, the environmental management plan, the public consultation and disclosure process and specialist study reports were finalised at the end of May 2011 and have been released for public review.
When asked about the Kimberley Process Certification Scheme (KPCS) in Sierra Leone, Joubert noted that the eyes of the world are on Sierra Leone as the place where the issue of ‘conflict diamonds’ triggered the formation of the KPCS.
“Ten years after the end of the civil war, the country has made tremendous progress and, as a company with a long-term strategy for Sierra Leone, Koidu Holdings has invested in extra measures at operations to help government implement the KPCS in line with the standards and governance achieved by other African diamond producing countries. Koidu would like to see Sierra Leone receive due recognition for the years of hard work and for what has been achieved by the government in re-establishing the country and ensuring the equitable distribution of the mineral wealth for all stakeholders. Sierra Leone has become a ‘good news story’ in Africa that needs to be told,” says Joubert.