The Democratic Republic of Congo's (DRC's) minister of mines signed off the environmental and social impact assessment (ESIA) report for the Tenke Fungurume copper/cobalt mining project, in Kinshasha, at the beginning of October.
Consulting engineering company Golder Associates marketing manager Jacquie Pastor says the submission of the ESIA was favourably received by the ministry, who commended Golder Associates on the standard of the report.
The report, which Golder Associates were instrumental in drawing up, outlined the potential effects of the various aspects of the project on the surrounding environment, from social effects concerning employment and relocation programmes, to potential biodiversity damage from air and water pollution, and post-mining rehabilitation effectiveness.
The signing of the ESIA is a large step forward for the project, which is expecting to begin production in early 2009. The mining project entails the construction of an openpit mine that will produce an average of 250-million pounds of copper a year and 18-million pounds of cobalt a year. The Tenke Fungurume copper/cobalt deposits comprise one of the world's largest-known copper/cobalt resources, and are capable of being developed into a large-scale, long-life, low-cost mine.
On-site infrastructure is to include a large construction camp, and permanent housing and support facilities for mine employees and the operations. The infrastructure has been designed and located with a view of significant future potential expansions.
Off-site infrastructure accounted for within the feasibility study includes offices in Lubumbashi and Kinshasa, relocated villager housing and schools, and medical and other facilities to improve social conditions in the communities within the Tenke Fungurume mineral concessions.
"The project is a large investment by any standards, but by Congolese standards it's huge," says Golder Associates principal Dave Walker, who explains that Golder Associates have been involved in developing the ESIA since 2004, when copper producer Phelps Dodge (now Freeport-McMoRan Copper & Gold), acquired an interest in the project.
Golder Associates' involvement in the project has not only been environmental, but geotechnical as well, specifically in the area of tailings dams, and groundwater supply and dewatering. The company's involvement in such matters is from concept and design through to implementation, says Walker.
The plant at the DRC mining project is a standard solvent extraction and electro-winning facility, whereby the ore is crushed, ground and milled to the necessary particle size distribution, and dissolved in acid, after which the copper is ‘won back'.
The waste streams from the counter current decantation (CCD) system, which is the first part of the solvent extraction process, go to the tailings dam.
"There are two things that are unique about the tailings dam at the Tenke Fungurume project," says Walker. "The first is a principle decision by diversified commodities producer Freeport to make the tailings dam a zero discharge facility, meaning it is not allowed to overtop. The second, which is something unique to historical operations along the Congolese copperbelt, is that water is to be recycled through the plant."
"It is not an easy or simple thing to do, from a process point of view, because you end up with a build-up of impurities after the water has evaporated, that one cannot really accommodate," says Walker.
To ensure zero discharge, the tailings dam at the project is fully lined, and is one of the only tailings dams of its kind in Africa, says Walker, who describes the layer as a large plastic layer underneath the entire footprint of the tailings dam, preventing any unintentional contamination of the groundwater or surrounding water systems.
"The decision to layer the tailings dam was agreed on in collaborative consultation with the client," says Walker. He says the geology of the area upon which the tailings dam is constructed mostly consists of porous limestone and dolomite, making it possible for polluted water from the dam to seep down into groundwater and reappear in a spring or stream nearby. "The client did not want a situation where people or biodiversity might have access to the contaminated water."
The tailings dam is currently 115-ha, but there is capacity for 140-ha when fully developed. It can hold up to 115-million tons of tailings over a period of about 30 years.
However, Walker says that there is further expansion planned for the future. There are plans to open up two or three additional lining areas so as to increase productivity, as well as plans to double the throughput in the process plant, going from 115 t/y to 230 t/y of copper.
"That is a process that will start within the next two to three years," he says, indicating that Golder Associates will be involved in the plans. "The mine is hoping to reach double capacity in about five years time. It is a subject of study that is ongoing, and which reflects the desire and intent of the new owners; Freeport."
Golder Associates consults mine prospectors on everything from feasibility study to design and overseeing the construction of specialist projects, such as mine water treatment plants.
The company performs a full suite of services, including ESIAs, relocation programmes where it consults all affected parties and liaises with government, ore reserve evaluations, closure planning, mine planning through its alliance with Ukwazi Mining, as well as ground and surface water investigations and design of infrastructure.
Golder Associate's projects outside of Africa are performed through a strategic alliance with Pretoria consulting engineering firm Akwalu, which specialises in mine planning and engineering.