Here you can read a simple description of how our process takes place.
Drilling and extraction
We use different kinds of drilling rigs in our production drilling. The purpose of drilling is to make holes that we then fill with blasting agent. As a rule, we drill to a depth of 13 – 14.5m, since we have chosen to have a bench height of 12 m in our mine. We normally drill 150 – 300 holes, load 50-100 tonnes of blasting agent and often release 300,000-1,000,000 tonnes of rock/ore with every blast.
We normally load waste rock with the help of electrically powered hydraulic diggers hydralgrävare. The waste rock is then loaded onto trucks for further transport to the waste rock dump, unless it is to be used in road building or other construction. The ore is loaded onto mine trucks using large wheel loaders for further transport to the primary crusher.
The primary crusher is about 30 metres high and can manage diameters up to 90 cm. once the ore has been crushed to the right dimension, it continues on an encapsulated belt conveyor making the 1 km transfer to the screening plant.
Here the ore is screened and divided by size before being transported up to the top of the north ore stockpile.
Via the belt conveyor, the ore reaches the top of the ore stockpile, where it drops into one of six compartments. Below the compartments in the ore stockpile, the right quantity and composition of ore drops onto an underlying belt conveyor to be transported to the concentrator.
First, the ore arrives at the primary mill, where the process becomes wet. Large quantities of water are added here in the mill. From the mill, it then continues to the first magnetic separation, where most of the material that is not magnetite is separated from the waste rock. After the first magnetic separation, the ore is pumped further to one of the three vertical mills for further grinding. After secondary grinding, the ore is pumped on to the second stage of magnetic separation. From magnetic separation, the concentrate is then pumped to a concentrate tank to be further pumped to a compressed air filter. There it dries and becomes finished concentrate.
When the process is completed, the ore is loaded onto trucks to be transported to the railway and the harbour.