The project is also interesting from a technical point of view. First, it is a selfmanaged project. TMC has been able to attract a core group of highly experienced mining and project management professionals, mostly familiar with the Finnish mining industry and/or nickel mining and processing. Rather than bringing in outside consultants and an EPCM contractor, the company has operated through a highly networked business concept, working in close co-operation with a selected group of leading partners, which includes Algol Oy/Kaitos (construction technology), Destia (construction–roads and earthworks), Grundfos, Metso Minerals, Sandvik Mining & Construction, Boliden, GTK, Gridpoint Finland (rock engineering consulting and research), Helsinki University of Technology, Lapland Water Research Ltd., OMG, Outokumpu, the Bioshale Consortium (biotechnology for black shale ores), Tampere University of Technology (bioheapleaching trials), the Finnish Funding Agency for Technology and Innovation (TEKES) (finance for bioheapleaching trials) and the Kainuu Employment and Economic Development Centre. TMC carried out the Bankable Feasibility Study in close cooperation with key suppliers.

Second, TMC is relying on innovative technology. The key step is bioheap leaching using techniques first studied by Outokumpu during the late 1980s. It is an energy-saving process route and has been chosen as the preferred technology for the Talvivaara project based on its favorable capital and operational cost profile, favorable environmental profile compared to smelting and the good performance data obtained with the technology in several trials with the Talvivaara ore. Riekkola- Vanhanen, known in Finland right up to the president as ”the bug lady,” was voted Natural Scientist of the Year by the Finnish Union of Experts in Science for her work in bringing Talvivaara to production. The full scale process utilizes parameters similar to those established at commercial copper leaching operations, with agglomerated ore particles being stacked to a heap height of 8 meters.

At the same time, Talvivaara started a joint research project on the downstream metals recovery process with OMG Finland at the company’s Kokkola operation. In 2005, OMG participated in the first private placement financing for TMC and also signed a 10-year/300,000 mt nickelcobalt sulphide offtake agreement with TMC, which was taken on by Norilsk Harjavalta Nickel when OMG sold the nickel business to Norilsk Nickel in 2007.

Process plant construction at Talvivaara was close to completion when E&MJ visited the site.
The tallest building seen here houses the metals recovery reactors.

The last Scandinavian Report (E&MJ, October 2007) summarized the history of the project to that point and outlined the mining and processing technology to be utilized. In August of this year, E&MJ visited the site, courtesy of TMC, to see whether the project was on track to start recovering metal. The short answer is yes, but not without some improvisation.

Construction and Connection
Talvivaara’s polymetallic orebodies, Kuusilampi and Kolmisoppi, are situated approximately 35 km southeast of the town of Kajaani and approximately 30 km southwest of the town of Sotkamo, in a largely uninhabited part of the Kainuu district. The mining property is located on the western side of the regional road 870 and is crossed by road 8714. The 870 links Rautavaara to the south with the national highway E 63-5 that connects Sotkamo and Kajaani (where there is an airport) with eastern Lappland to the north and the cities in the southern part of Finland. The regional roads are being upgraded to cope with the future level of traffic to and from the operation. A 43-km power line from Vuolijoki, near the old Otanmäki mine south of the Oulujarvi lake, was completed early in 2008.

In value terms, Talvivaara ranks second only to the nuclear power plant in Olkiluoto among current Finnish construction projects and it is estimated to require about 3,500 person-years of work. Total planned capital expenditure breaks down to: metals recovery plant €150 million, buildings €100 million, earthworks (including the heap foundations, mine roads) €100 million, and the materials handling equipment (crushers, stacker, reclaimer, etc.) €100 million. Capital expenditure in the first quarter of 2008 amounted to €62 million, bringing total investment in the project to that date to €187 million.

Of the total mine area of 61 km2, approximately 20 are being used for construction, including 14 km2 for the heap foundations, a gypsum residue basin for future use as a process waste area, water management ponds and other structures that must be isolated from the natural environment. The Environmental Permit regulates these structures. Mining waste was unusable for construction because of the high pyrite content but contractors have been able to quarry suitable material on the property.

Destia Oy, a state-owned company that was previously the Finnish Road Enterprise, was able to provide the full range of competences that TMC required, even though mining is a new business area for the company. Responsible for engineering and measurement, construction, special construction and maintenance work, Destia planned and designed the mine area road system including 25 km of new road. However, five other major contractors and perhaps 80 subcontractors have been involved, employing over 1,000 people by February 2008 and about 1500 in the May – July peak period. These firms removed 50,000 mt rock and 20,000 mt of overburden daily.

The mine office premises were completed in February 2008 and the TMC staff moved there from a temporary office in the town of Sotkamo. The process equipment, maintenance operations, training, administration and other work spaces are housed in 770,000 m3 of buildings ranging from the 33-m-high reactor building to small transformer and pump enclosures. The multiple pumps supplied by Grundfos, as well as fans for heap leaching and conveyors, are driven by more than 300 AC drives supplied by Vacon, the Finnish-based but worldwide supplier of AC drives from 0.25 kW to 5 MW.

Initially the water supply is being drawn from Lake Kolmisoppi on the property but after 2010 the site will later draw water from Nuasjarvi, the lake on which Sotkamo is located. Water and solution movement will take place through 100 km of long-distance pipe work while the 33,000-m3/h leaching and solution collection system will eventually use 6,700 km of pipe work, all of which is being supplied by KWH Pipe based in Vaasa.

Open-Pit Mining
The Talvivaara mineralization is located in the southern part of the Proterozoic Kainuu belt. This belt is approximately 200 km long, with a maximum width around 40 km, and consists mainly of quartzites and mica schists lying unconformably on an Archean gneiss complex. Three mineralogical ore types can be distinguished in the Kuusilampi and Kolmisoppi orebodies: fine-grained dissemination, sulphide breccia and metacarbonate.

About 90% of the mineralization at Talvivaara is hosted by high grade metamorphic black schist that is intensely folded; the remainder occurs in metacarbonate rocks, phyllites, mica schists, quartzites, graywackes and quartz wackes. The main minerals are pyrrhotite, pyrite, chalcopyrite, sphalerite and pentlandite. The sulphide content typically ranges 15%-25% and the average sulphide mineral content of the orebodies is 21 wt%. The black schist also contains up to 7% graphite. The ore is hard and outcrops as ridges. Unlike nickel ores hosted in ultramafic rocks with a high pH, which makes leaching difficult, these deposits have a pH below 3.00.

The mineral resource has been classified using the Australian JORC code with 0.07% nickel cut-off at 569 million mt, containing 0.23% nickel, 0.51% zinc, 0.13% copper and 0.02% cobalt. Some 80% of the mineral resource is in measured and indicated categories totalling 336 million mt at 0.27% nickel, 0.14% copper, 0.02% cobalt and 0.55% zinc.However, in-fill drilling at the Kuusilampi deposit resulted in the resource being substantially increased in December 2007 to 1.32 million mt of nickel (at 0.07% cut-off) within the pit outlines.

Photo shows a 35,000-mt blast at Talvivaara but three days later Forcit was scheduled to fragment 180,000 mt.

The present resource for this pit is 430 million mt nickel but there is 12 to 18 months of in-fill exploration drilling to be done within the pit area. As a result of a mine plan review based on the latest ore resource figures, due to be completed late in 2008 or in early January 2009, the dimensions may change. For instance, the final depth may be increased to 400 m. Kolmisoppi, which may be mined later, measures 1,500 m in length by 30- to 350- m, to a depth of 300 m. In two years time, the company will drill the area between the two outlined pits, ahead of finalizing the design of the Kolmisoppi pit. And there is a lot of regional exploration potential to look at in future too. By 2012 there will be 150 people in the mining department.

Overburden removal and leveling of the ore surface started ahead of schedule in late October 2007 and a fleet of up to 15 excavators and dump trucks were at work during the stripping and mine preparation phase. The first stripping phase removed overburden from a 30 ha area; the second phase is to start soon. TMC will contract part of waste rock stripping in future.

Mining has started close to the footwall contact, with the first blast on April 1, 2008. Scheduled production for 2009 is 15 million mt ore and 7 million mt waste but later the total amount of material will range from just over the 15 million mt of ore to as much as 60 million mt/y depending on the waste rock removal rate required. TMC is looking to blast 500,000 to 1 million mt per week. Forcit is contracted to do this work under a seven-year deal. For flexibility and good fragmentation the company is using pumpable emulsion explosive.

TMC is using the Sandvik drill fleet discussed in September’s issue (pp. 114, 116, 118). These three rigs are drilling 15- m benches with 17- to 18-m holes at a 10° inclination. Together with a Sandvik DX800 they should be able to drill enough holes for the extraction of 25 million mt/y, sufficient for the first three years of mining at the presently envisaged rate, but the fleet will be increased to seven units to achieve the maximum production rate. TMC expects to stick with 127-mm-diameter holes for ore as this size is giving the fragmentation they want but may use bigger holes for overburden blasting where the degree of fragmentation is not critical. The drill pattern is 4.3 x 3.9 m.

Mine Manager Arto Suokas, who previously worked at the Forrestania nickel mine in Australia and also at the Tara mine in Ireland, explains that the DPi 1500 top hammer drilling rig was chosen ahead of competing units because of its Canbus technology, ease of maintenance and the proximity of the manufacturer’s plant at Tampere. From the drilling mode options available for this rig TMC chose one hole drilling to depth, which allows one operator easily to manage two machines, increasing productivity and decreasing blasting costs on account of the greater drilling accuracy. Suokas expects further improvement when GPS navigation becomes available from Sandvik. The rigs are running well, he said, and were half way through the October production plan at the time of E&MJ’s visit.

Operator training at Talvivaara is provided by the North Karelia Adult Education Center, which has one of the first Sandvik SimDriller training simulation systems. As this is an area of high unemployment the Center is receiving European Union financial help. The SimDriller has proved helpful in pre-production operator training and provides a reliable aptitude testing option. However operators can only learn the effect of ground conditions on the drill rig’s responses on the genuine article.

TMC is now also responsible for loading and hauling ore to the crushing system, using an Hitachi EX3600 hydraulic excavator presently teamed with one Hitachi EH3500 AC II truck. However, a second EH3500 was being assembled when E&MJ visited, while a third will be assembled by year-end. This truck will have a new wheel motor seal design that will be retrofitted to the two machines already delivered. The equipment is assembled and supported by Rotator Oy, the Hitachi dealer in Finland. The EX 3600, which will be backed up by a Komatsu WA1200 wheel loader that is currently awaiting an engine, should load 170-180 mt material to the EH3500 trucks with five full bucket loads but HCM is still studying the optimal wear material requirements for the machines, which will affect the loading rate as will the load capacity of the tires. These are Torch tires from China and the manufacturer is scheduled to run checks on their performance in September.

Destia is loading the waste rock with one new Hitachi Zaxis ZX 870LCR (long carriage rock) hydraulic excavator on to a fleet of seven new Hitachi EH 1100-3 trucks which have a 65-mt payload. Four of these were working in August with three more on the way. The contractor also has a used truck on site.

So far, says Suokas, all the deadlines for the open pit have been met.

Crushing and Screening
Sandvik Mining & Construction is responsible for the complete crushing system apart from the electrical and plant automation system. The company completed installation of the complete 2,500-mt/h-capacity secondary and tertiary crushing, screening and conveying system on schedule despite the considerable pressure on manufacturing facilities resulting from a large order backlog.

Talvivaara’s loading and haulage fleet currrently comprises an Hitachi excavator and EH3500 ACII truck,
with two additional trucks undergoing comissioning.

The average haul distance from the mine to the primary crusher will be about 600 m and the 125-mm product will be fed from an intermediate stockpile to four PF 16/30 feeders in the secondary crushing section. These feed four LF2640T triple deck screens which discharge underflow to the crushed ore storage and direct overflow to two of the CH880 crushers. One of these supplies four more PF 16/30 feeders working with four LF3060D screens. The underflow again goes to the crushed ore storage while the overflow goes to three tertiary stage CH880 crushers that recycle product back to the feeders and screens. The other secondary crusher similarly supplies underflow to ore storage and overflow to the other three tertiary crushers via the other four LF 3060D screens. The tertiary product is again recycled to the screens.

It is the delayed installation of the primary gyratory crusher that has required TMC to improvise. A contractor was prepared to loan a Metso LT140 and three LT120 mobiles as well, with one of the LT120s on stand-by, to do in-pit primary crushing at the face. These machines are loaded by a variety of hydraulic excavators and the crushed product discharged by conveyor is stockpiled by various wheel loaders ready for the Hitachi EX3600 to load onto the EH 3500 truck. The LT140 has a radial stacker so it can build a heap for the EX 3600 excavator to load on to the trucks. The Komatsu WA1200 will load from the two LT 120 crushing plants but at the moment this job is being done by smaller Komatsu wheel loaders belonging to contractors.

The Hitachi trucks dump the primary crushed ore to the intermediate stockpile ahead of the secondary and tertiary crushing plants. These were delivering 300 mt/h to the agglomeration plant when E&MJ visited but will go to 1,000 mt/h when the second EH 3500 AC II truck starts hauling and by year-end the crushing rate should be 1,500–1,700 mt/h with all three Hitachi trucks working. P80 of the final product to agglomeration is 8 mm.

Agglomeration and Heap Leaching
Agglomeration with sulphuric acid is carried out in equipment supplied by Metso Minerals in order to consolidate fines with coarser ore particles. A long conveyor delivers the product to the stacker on the primary leach pad.

These eight Sandvik cone crushers will carry out secondary and tertiary crushing of ore ready for agglomeration.

Critical earthworks for the construction of the heap foundations and water management systems were completed in fall 2007 before the winter set in. The heaps and water containment ponds are underlain by compacted layers of soil, bentonite mats and welded plastic films. Effective water management is crucial for the operation and both the pipe work specialist KWH Pipe and the pump supplier Grundfos have played key roles at Talvivaara, the latter being one of the first project partners. In addition to the water addition pond above the leach pads there are also four feed ponds for each leach pad section. KWH Pipe is equipping the heap pad with piping, laid on the bottom of the pad, through which low-pressure fans can supply air to the stacked ore.

Water flow through the heap started in July-August so the whole operation can start up in the fourth quarter of 2008. Although the feasibility study production forecasts were based on an 85% recovery rate, TMC expects to get 87%-90% metal recovery in 18 months so the first primary heap will be leached until 2010, by which time the secondary heap pads, already under construction, will be completed. The secondary leach will recover metals from those parts of the primary heaps where leach solution has had poor contact. Such areas include, for example, the slopes and possible precipitates formed inside the heap. This phase mostly recovers copper and cobalt because their leach rates accelerate after the nickel and zinc have been removed. After secondary leaching, the barren ore will remain permanently on the secondary heaps and will become benign in about 20 years. Sulphuric acid storage capacity is 15,000 m3.

Metals Recovery
Talvivaara developed its metals recovery techniques in collaboration with OMG in Kokkola, Finland, based on a process which is currently being used commercially by OMG Kokkola Chemicals. The first metal recovery pilot started in March 2006 at the Kokkola facility.

The current production plans are geared to full rate annual production of 33,000 mt nickel, 60,000 mt zinc, 1,200 mt cobalt and 10,000 mt copper in the form of nickel-cobalt, zinc and copper sulphides. On this basis nickel is expected to account for approximately 75% of total revenue, zinc for around 15.5%, copper for about 5% and cobalt for the balance.

Pregnant leach solution will be bled from the leach circulation system for metals recovery in the Reactor Building. Here hydrogen sulphide will be used to extract the metal values sequentially by precipitation in Outotec OKTOP agitated reactors. H2S will be produced on site. The precipitates will be sent to Outotec thickeners outside the reactor building. After the metals are removed, the solution will be further purified and returned via a raffinate pond to irrigate the heaps. The thickened precipitates will be filtered to produce saleable metal products. Outotec’s reactor and thickener supply contract with Talvivaara was valued at €40 million. Filtration takes place in Pannevis units supplied by Larox.

There will be two identical lines of 15 reactors linked to thickeners, plus three neutralization reactors. The first phase set of 17 reactors has been installed this year and the remaining 16 will be delivered in 2009. The first step in each line is the precipitation of copper in two reactors, each with an operational volume of 280 m3. They are being fabricated from fiberglass reinforced plastic (FRP) in Finland and each will have a rubber-lined stainless steel agitator powered by a 160 kW motor. Initially TMC will not carry out the copper recovery step so these reactors will be installed in both lines next year.

The three zinc sulphide recovery reactors in the first process line are ready for use. These also have an operational volume of 280 m3 and are made from FRP. The rubber-lined AISI 304L stainless steel agitators are also driven by 160-kW motors. Similarly there are three pre-neutralization reactors installed in line one now. With a greater operational volume (376 m3), these units are built from AISI 304L stainless steel, as is each agitator. A 250 kW motor powers each agitator. In these reactors TMC will establish the slurry pH value suitable for the following nickel-cobalt precpitation step, using lime milk and precipitating aluminum. Lime addition will require the import of about 1 million mt calcium carbonate annually that will come from Gotland.

The leach heaps will rest on welded plastic liners,
bentonite mats and compacted soil layers.

To precipitate any remaining metals there are three 376-m3 operating volume LDX 2101 stainless steel neutralization reactors, each with an LDX 2101 stainless agitator driven by a 132-kW motor. Achieving this reaction requires pH adjustment using fine calcium hydroxide so gypsum and small amounts of metal hydroxides will be formed.

There is a hydrogen sulphide gas absorption reactor in each line, these being FRP tanks with an operating volume of 120 m3, each fitted with a rubber lined 304L agitator powered by a 200-kW motor. These reactors will absorb hydrogen sulphide from the vent gases of the precipitation reactors into a sodium hydroxide solution. Finally the spent solution is returned to irrigate the heaps.

Outotec says the scale-up of the reactors is based on chemical testing, physical modeling and computational fluid dynamic analysis. Water testing of the first line was scheduled to start at the beginning of September 2008.

In all, the technology is expected to result in lower capital and operational costs than a substantial proportion of other nickel mines making the Talvivaara project less susceptible to price variations of commodities. Operating cost projections for the major activities are: metals recovery 51.4%, mining 23.3%, materials handling 12.3%, bioheap leaching 7.7%, water management 1.6%, freight 2.1%, and general administration 1.5%.

However, TMC is still pursuing R&D projects concerning aspects of bioheap leaching and is also studying the use of biotechniques in the metals recovery process, an exercise that has been remarkably successful, the company says. TMC also plans to extend the facility’s range of inputs to additional polymetallic intermediates from external sources and also the recovery of manganese contained in the mine’s pregnant leach solution. To this end the company made an offer of approximately €85 million of convertible bonds to institutional investors during May this year.

Norilsk Harjavalta Nickel Oy is making major investments at the Harjavalta plant to accommodate the new material stream. The company is spending €64 million over two years on a calcination plant to treat the NiCo sulphide. Norilsk has already expanded capacity at Harjavalta from around 54,000 mt/y in 2007 to 60,000 mt/y in 2008 and in January this year Lahti, Finland based Vaahto announced that its Japrotek subsidiary would deliver a new leaching autoclave to Harjavalta in March 2009. This will help Norilsk boost output to its target of 66,000 mt next year. Meanwhile, zinc and copper sulphides sales are still under negotiation.

Long-Term Proposition
According to TMC, full production more than 2 million mt of material will be transported to or from the mine site annually. Consequently, although the infrastructure in the Talvivaara area is remarkably good for a relatively remote area, some investment in improvements and extensions are required. The regional road linking the mine site to the main national highway between Sotkamo and Kajaani is being improved and a rail terminal at the mine will be connected by a 26-km track to the existing line at Murtomäki, between Kajaani and Iisalmi, which is being constructed by VR-Track Ltd and should be operational by August 2009. The filtered NiCo sulphide precipitate will travel to Harjavalta in sealed containers loaded by forklift trucks, onto road vehicles until the rail link is completed. The Finnish state has reserved €52.2 million for these works but Talvivaara Infrastructure Ltd. will initially fund the rail link.

Talvivaara is committed to environmentally responsible and safe conduct in all its operations. There may be further legal challenges to TMC’s permits but the company believes they have no merit. The main indicators monitored for the state of the natural environment are: soil and groundwater, surface waters, aquatic bottom flora and fauna, birds, plants, fish and fishing, Russian flying squirrels, social impact assesment and traffic.

To date, the Talvivaara project has achieved a very high level of safety. TMC itself has recorded no accidents and the many contractors have only reported less than ten Lost Time Injuries, all of a minor nature. There is a continuous safety monitoring regime and a safety education program.

The key components of Talvivaara’s long-term strategy include:
• Securing cost-effective exploitation of the Talvivaara deposits using the bioheap leaching technology
• Capitalizing on the potential for additional value creation through application of bioheap leaching technology to other nickel resources.
• Growth through exploration of additional resources in Finland, and
• Leveraging the project development and operational expertise in the long-term.