Keeping it clean
Luis Merino, managing director of the Aguablanca nickel mine in southern Spain, talks to Jayne Flannery about this flagship operation within the Lundin Mining Corporation.
The Aguablanca nickel-copper sulfide deposit is located in the province of Badajoz in southern Spain. The extensive deposits, which were not discovered until the early 1990s, lie almost exposed on an inconspicuous hill that looks very much like any of the other similar hills that break up the plains in the dry, arid lands to the east of Andalucia.
The operations consist principally of a large open pit mineÔÇöexcavation of the ore features the sub-level open stoping method with cemented aggregate fill. Last year, standard mining and earth moving equipment was used to move a mighty 1.9 million tonnes of rock. This was then fed through an on-site processing facility that relies on milling and flotation techniques to produce a bulk nickel-copper concentrate.
This concentrate is then sold on to a single client in China where it is smelted and refined. Unusually, the processing plant at Aguablanca has the flexibility to produce separate copper and nickel concentrates with minimal loss of nickel to the copper concentrate. This is achieved by a special process that exploits the flotation rate differences between the fast floating copper and the heavier nickel minerals.
Luis Merino, managing director of the Aguablanca mine, explains the synergies that exist between the two metals. ÔÇ£Nickel is the principal component of stainless steel with an enormous range of applications. Meanwhile, copper has properties ideally suited to electrical conduction.ÔÇØ
When the mine was acquired by the Lundin Mining Corporation (LMC) in July 2007, it immediately added a vital new dimension to the companyÔÇÖs portfolio. As a diversified base metals mining company, which already had operations in Portugal, Sweden and the Democratic Republic of Congo, LMC was keen to add an operation to mine and process nickel, a relatively rare metal found nowhere else on the Iberian Peninsula. The idea was that a capability in nickel would add value to its existing copper mining operations.┬á┬á
ÔÇ£There is another small nickel mine in Finland, but that is all there is in Europe. Copper, on the other hand, is much more common. I know of two copper mines in Spain and a very large one in Portugal,ÔÇØ Merino says.
ÔÇ£Aguablanca is in a great location,ÔÇØ he continues. ÔÇ£It is close to the Pyrite belt which means we have no shortage of skilled labour; and there is good infrastructure and transport links. Spain also offers a very stable operating environment which makes it easy to do business here.ÔÇØ
Commercial production of nickel-copper concentrate had begun in 2005 under the previous owner, Rio Narcea Gold Mines. However, the change of ownership was quickly followed by the unprecedented economic downturn, which saw the price of all raw materials and commodities plummet. 2008 was an extremely difficult year for Aguablanca and saw many development activities put on hold.
Now, the mine is fully operational again and last year saw a dramatic leap in ore production of almost 25 per cent. ÔÇ£We have seen a jump in production to two million tonnes per annum, which means we are now excavating in the region of 8,000 tonnes of ore each day,ÔÇØ Merino states.
The estimated life of the open pit operation is four years using the open pit method; then the company will look towards developing underground operations. ÔÇ£Exactly how we choose to move forward will be very much influenced by metals prices, but we have already┬á invested heavily in a feasability plan to look at how we might take the mine forward in the long-term. To date, we have covered some 18,500 metres in an exploratory drilling programme,ÔÇØ he says.
Merino is particularly proud of the management teamÔÇÖs success in implemeting a far-reaching environmental strategy, as well as a health and safety programme to safeguard the 320 people who work on the site, either directly or as sub-contractors. ÔÇ£Safety and the environment have been an absolute priority and we have dramtacially decreased dangerous or damaging incidents. There has been a 40 per cent reduction in accident rates since we took over,ÔÇØ he comments.
ÔÇ£We maintain a very good relationship with the environmental authorities of the province and I believe we are breaking new ground in the use and reclamation of land. At the same time, we have achieved a zero discharge record for both liquids and gases. We can honestly state that we have never had a single environmental incident.ÔÇØ
So far, 500,000 cubic metres of soil has been carefully stockpiled for latter replacement and up to 80 per cent of the 5,300 acorn trees affected by the mine have been re-sited elsewhere. To date, 139,000 square metres of waste dump surface has been carefully restored. It is hoped that when surface operations are complete, the restored land can be returned to its former ownersÔÇösmall-scale subsistence farmersÔÇöif they want this option.
Meanwhile, 50 per cent of the water used in processing is derived from sewage treatment plants. Aguablanca is the first mine in Spain to make use of water for processing from this source and Merino hopes to set a new benchmark for environmental good practice and water conservation in the industry.  
Looking to the future, Merino is keen to mention the Ôé¼724,000 investment that is currently being made in expanding the siteÔÇÖs flotation capacity. Metallurgical laboratory tests have shown that nickel recovery could be enhanced through greater residence time in the flotation cells that lie at the heart of the processing operation. As a result, four new flotation cells (each of 40 cubic metre capacity) will be phased in this year, allowing for a new residence time of almost an hour.
ÔÇ£We expect demand to stay buoyant; and the improvements we have made in productivity should ensure a long and prosperous life for the mine. Meanwhile, we are also demonstrating how good management practice can lead to many improvements in accident reduction and environmental integrity. Our achievements at Aguablanca are something that everyone involved should be proud of,ÔÇØ he adds.
