Outotec scope in Kevitsa
The Outotec installed base in FQM Kevitsa consists of an entire concentrate process equipment product line including grinding mills, flotation cells, thickeners, filters, samplers, analyzers, and automation systems. Outotec has delivered one AG Mill, two Pebble mills, 73 Outotec TankCells ranging from 20 m 3 to 300m 3 cells, three High Rate Thickeners, two Outotec Larox PF 25 m 2 filters (which will be expanded to 32 m 2 ), an Outotec PSI 500 particle size analyzer for the grinding circuit, and a Courier 6i elemental analyzer for the flotation circuit for froth control along with 36 FrothSense imagers and the Outotec ACT(Advanced Control Tool) for process optimization in flotation. Outotec has also delivered the Outotec Integrity concentrate reporting tool.
“The previous owner of the site had made the order for the equipment from Outotec, but would we have something different if we’d had the choice? I don’t think so. We have Outotec equipment in our other mine sites as well,” reasons Anthony.
“Efficiency is key. We need to perform at the industry level standard, which comes through well-working equipment, planned maintenance, usability, and results as in availability. Downtime is expensive, and reliable equipment is key in the equation,” Anthony continues.
“For example, anyone can build a flotation cell, but when it comes down to availability there are only a few providers in the market that you would select to achieve a robust cell with high availability and to avoid shut down of the entire plant due to sanding issues,” Anthony states.
Working together with the customer for better process results
Along with the equipment deliveries, Outotec supported the FQM Kevitsa project by supervising the installation and commissioning the equipment. Outotec provided ramp-up services, including process support and on-site expert services. These included installation support and supervision mostly for the flotation and grinding mills, as well as metallurgical assistance by providing the services of a process metallurgist.
During the ramp-up phase, it was discovered that the filters were bottlenecking the process as the throughput rates were increasing. “The feasibility study was done by a third party, and it provided us with quite a wide large scale of throughput rates. Based on that study, too small filters were engineered and delivered to the project,” Anthony explains.
To remove the bottlenecks, Outotec delivered two filter expansions to the Outotec Larox PF filters by adding plates and increasing the capacity and throughput rate by almost 30%. “After the expansion, Kevitsa will be more flexible in terms of parameters and operational functions, and the process will not be that sensitive to changes,” states Kari Maalahti, Outotec Sales Manager for Service Operations.
Outotec will also provide scales for the filters to enable better control. “The adjustments can be made automatically based on the cake weight,” explains Tommi Lanki, Outotec Sales Manager for Dewatering. “On time weighting system indicates the solids load inside the filter chambers, which allows us to control the pumping time automatically and optimize the cycle time accordingly to get optimal capacity out of the filters. Also, an automation modification was made recently according to the customer’s needs in order to reduce the air-drying time while still meeting the desired moisture targets. This generates multiple savings for the customer. The compressed air usage can be reduced, which provides savings in energy usage, and also they will be able to reduce the total cycle time in order to get higher capacity out of the filters.” Tommi continues.
The filters were optimized to run both nickel and copper to optimize availability and minimize downtime.
“We don’t have the required in-house competence for the specialized automation equipment. With the floats and mills, the maintenance issues are more related to the pumps and pipes, which we can handle ourselves,” Anthony explains.
“Outotec equipment has worked well. We have faced some challenges with the samplers, but these are being solved as well. We have been able to work according to the planned maintenance, and there have been no big surprises or problems. We have our own maintenance performance reporting tool that reports on safety, maintenance, quality, and production throughput to monitor the plant operations,” Anthony adds.
In addition to the service agreements for the automation, Outotec has also provided Kevitsa with mill lining services and a two-year O&M (Operations and Maintenance) agreement for the filters. The O&M filter agreement includes an Outotec filter service representative available onsite 8 hours per day, including maintenance work, working with the process team at the Kevitsa plant and training the operators in the filtration process. The O&M also included the start-up and basic support for mechanical, process and automation work. In addition, Outotec has a remote service available for the Kevitsa site.
“All the sites where I have worked have had Larox filters. It is straightforward yet sensitive equipment. We have definitely benefitted from having the Outotec O&M filter agreement. The ramp-up has been easy, and we have received training at the same time,” Freddie Woulters says.
“We have tried training the filter operators on our own at other sites, but this only ended up costing lots of money due to the downtime as the operation requires specialized skills that take years to learn. The filters are such detailed equipment that we do not have our own competence. After using Outotec’s own filter personnel, the availability has gone up to 90% and remained there. Here at Kevitsa, the filter O&M has been good from the start. The filter is just there and we do not even think about it – we do not have the time for that. Our core business is making copper and nickel, and that’s where our focus is,” Anthony concludes.