Reportage in Bergsäkert 2022
Air-driven Simba yields successful results
At the beginning of the year, Bergteamet carried out rock drilling work for LKAB in Malmberget. Over three months, approximately 6000 meters were drilled with a Simba M6 long-hole rig equipped with an air-driven down-the-hole hammer.
Usually, rigs equipped with water-driven down-the-hole hammers are used in Malmberget. In certain conditions, this is not optimal.
“Here in Malmberget, it sometimes happens that the rock is broken or consists of sections with gravel and clay. Then it is impossible to use water-driven down-the-hole hammers when we drill, explains Björn Öderyd”, LKAB’s drilling manager in Malmberget.
The composition of the rock causes the borehole to collapse or become clogged when water and drill cuttings meet and form a thick mass.
Air is best suited
In these conditions, the best alternative is to use an air-driven down-the-hole hammer. Then the hammer is on the drill unit that is inside the rock.
“The air that drives the drill simultaneously blows away the cuttings. We only add a little water mist, a small amount of water, to reduce the dust”, explains Mats Ragnarsson, Bergteamet’s Site Manager in Malmberget.
“The airflow and the high air pressure keep the masses away from the borehole very effectively”, adds Björn Öderyd.
The machine that Bergteamet uses is the long-hole rig Simba M6 C-ITH, equipped with an air-driven down-the-hole hammer. A powerful air hose and a large compressor are connected to the machine, a package that, due to its size, can only be moved with a wheel loader.
45 meter long holes
Bergteamet has worked with rock drilling in Malmberget on a couple of occasions. The first time was in the spring of 2020 in the areas Prinsen 996 and Fabian 955.
“Then we drilled a total of about 6000 meters, and the longest holes were about 45 meters”, says Mats Ragnarsson.
At the end of 2021 to the beginning of 2022, Bergteamet carried out the latest rock drilling assignment, this time the work also took place in Fabian 955 but also Prinsen 1023.
“This time we also drilled about 6000 meters”, says Mats.
Completed and cleaned
The purpose of the rock drilling was to complement LKAB’s drilling and complete the holes that could not be finished with water-driven down-the-hole drilling, as well as to clean up holes where the rock had collapsed.
“We cooperated very well and complemented each other very well. The air-driven drilling was very successful and ensured that all holes were drilled and cleaned”, says Mats.
“We have an excellent collaboration with Bergteamet, they work with great flexibility, want to solve all challenges, and have knowledgeable staff. They could help us very well with their air-driven down-the-hole equipment”, says Björn Öderyd.
Reportage in Bergsäkert 2022