"Our recently purchased Metso Lokotrack LT1213S has had a promising start – even better than we thought. Using this modern plant, equipped with an impact crusher and screen, we are able to meet the growing need for recycling crushing," Hiironen says.
Better transportability clinched the decision to go for a smaller model
Since 2008, Kivikolmio has used Metso's track-mounted Lokotrack LT1315 impactor plant that has crushed altogether more than two million metric tons of asphalt and concrete. The hourly recycling crushing capacity has varied between 100 and 180 tons.
According to Mika Hiironen, the plant's excellent transportability clinched the decision to downgrade to the next smaller class of Metso impactor plants:
"Despite including a screen, the LT1213S is easy to transport without having to be dismantled. The feed hopper extensions and side conveyors fold hydraulically, which makes it faster to prepare for transport. We save at least one flatbed-load per transport, which creates considerable savings during the year," Hiironen points out.
"We selected Metso as the supplier based on earlier, positive experiences. We also have confidence in the maintenance offered by the Finnish manufacturer," he adds.
Hourly capacity of first project approximately 170 tons
Kivikolmio has a multi-year agreement with NCC Industry to crush recycled asphalt at eight different locations in southern and central Finland.
The LT1213S plant's first, approximately 60,000-ton asphalt job was begun at the end of April in Nokia at the Myllypuro quarry. The initial experiences were very positive.
"We crush and screen asphalt for NCC to a grade of 0–16 mm for recycling. On the very first days we already reached an hourly capacity of about 170 tons and on the best days 2,400 tons, even though we are still in the process of fine-tuning the machine," says Hiironen.
The new Lokotrack works in closed circuit in which case the overflow from the screen – roughly one third of the material flow – is looped back into the crusher by a return conveyor. Over the first few days, fuel consumption was approximately 40 liters per hour.
The screen module of the machine is a dual-slope DS series single-deck screen with 22-mm steel mesh at the top and 20 mm steel mesh lower down.
Blow bars targets 40,000 crushed tons
Kivikolmio uses Metso's X-win-type, martensitic blow bars for recycling crushing. The goal is to crush about 40,000 tons using one set of blow bars. In the LT1213S, spacing between blow bar and breaker plate is adjusted hydraulically.
"We will gain more specific consumption and wear data as we are able to fine-tune the crusher settings. Also how abrasive the recycled asphalt is varies significantly from one worksite to another," Hiironen points out. "The objective is to use the LT1213S to crush approximately 200,000 tons this year, of which half is asphalt and half concrete. We also invest in quality when it comes to concrete. We take care of all of Rudus's concrete crushing needs that the company markets under the Betorock product name."
Tight quality control in recycled asphalt
A renovated asphalt plant was started up at NCC's Myllypuro quarry at the beginning of May, which has a capacity of 300 tons per hour. The plant supplies remix asphalt for areas requiring surfacing in the Pirkanmaa region.