Kaunis Iron’s open-pit mine in Pajala is just the starting point of the ore’s journey to customers around the world. Here you can read about the process to refine the much-wanted iron ore.
Drilling and blasting
In the open pit, holes are drilled first of all and filled with blasting agent. Usually, 150 – 300 holes are drilled, which are charged with 50-100 tonnes of blasting agent, which then releases 300,000-1,000,000 tonnes of rock and ore in each salvo.
The ore released in blasting is lifted by front loaders into dumpers and then driven to be crushed in the primary crusher.
The ore is tipped into the primary crusher, and when it has been crushed to the right dimension it travels on a long enclosed belt conveyor to the screening plant for sorting.
In the screening plant, the larger pieces are separated from the finer fragments before being transported to the stockpile where they are stored.
In the ore stockpile, the ore is sent down into one of six compartments. Below the compartments, the right amount and composition of ore is dropped down to a belt conveyor underneath for further transport to the concentration plant.
In the concentration plant, grinding takes place in several stages. Magnet separation is used to separate the magnetite from the waste rock, which is then processed into a fine powder – finished concentrate.
The ore is loaded onto covered lorries to be transported to the trains in Svappavaara.
Reloading onto trains
At the railway terminal, the ore is reloaded from the lorries onto trains that transport the ore to Narvik.
Reloading onto ships
In the ore harbour in Narvik, the ore is loaded into ships for further transport to the customer.
The primary crusher
In the primary crusher, which resembles a gigantic mortar and pestle measuring 30 m, metre-sized blocks of ore are crushed into pieces measuring about 15 cm.
In the screening plant, sorting takes place, where large chunks of ore are separated from finer pieces.
Inside the concentration plant, the primary mill grinds the pieces of ore down to small grains measuring about 2.5mm.
Magnetic separators 1
In the concentration plant, there are also magnetic separators. Here, the iron ore is grabbed by magnets and separated from other material.
In the vertical mill, which is also in the concentration plant, the ore grains are ground down to a fine powder which can be compared to cornflour.
Magnetic separators 2
Here the ore is once again separated from other material with the help of magnets.
In the concentration plant, water is pressed out of the ore before it is filtered.