At a time when many mining companies are reducing their output to adjust to lower demand, Russia’s Karelsky Okatysh iron ore mine continues to increase production with a positive outlook on the future.
The reason is that this young mine, founded in 1982, is now reaping the benefits of investments it has made over the last few years in modern technology and automation solutions.
Karelsky Okatysh is owned by Severstal, the second largest producer of iron ore pellets in Russia, and one of the world’s most profitable steel producers. It is also one of Russia’s most modern mining operations, accounting for some 20 percent of the country’s iron ore.
The nearest town is Kostomuksha, about 12 km to the southwest, which has more of the look and feel of a college campus than a typical mining settlement. Here, more than 5 000 people out of a population of 30 000 are engaged in the mining industry in one capacity or another.
The ore from this region is magnetite quartzite which produces high quality pellets with an iron concentration of up to 68 percent. Four pits are active on the site with two of them responsible for most of the output – Central and Korpanga – which have a combined lifespan of 34 years and probable reserves of 480 billion tonnes.
Central Pit, which was the first to be mined, and will probably be the last, is the largest one. It is currently 5 km long, 2 km wide and 300 m deep and will eventually reach a depth of 460 m.
The company’s strategy is to not allow the fluctuating price of iron to affect its operations, but rather to increase production year on year through continuous efficiency improvement. Investments in lean technology and automation solutions have made a great contribution in the effort to meet this goal.
For example, when a hauler is loaded with rock, a sensor is able to measure the ore-to-waste ratio contained in the load. If the sensor detects less than 10 percent ore, the material is sent to waste; if the ore is rated in the 10-to-25 percentile, the ore is directed to the crusher, and if the load grade is more than 20 percent, the ore is transported to the railway and sent directly to the ore dressing plant.
Of the 35 Mt of ore produced each year, 10 Mt are crushed in the pit while 20 percent remains in the crushed tonnage.
Total application package
The mine’s drill and blast fleet includes four DM-M3 diesel rotary blasthole drills as well as a FlexiROC D50 and a FlexiROC D60, all from Atlas Copco. Added to these are a number of Russian SBSH blasthole rigs.
The DM-M3 units, which originally made their name in coal mining, are used here for drilling the main production holes with the FlexiROC rigs doing the pre-splitting work. An Atlas Copco Christensen exploration rig, which is used on a daily basis for core sampling, completes the total application package.
The DM-M3 rigs arrived at the site in early 2012 and can be used to drill in a single pass to depths of 12 m. However, these rigs are used for multi-pass drilling, using two 12.2 m pipes, to drill to a depth of 21 m. They typically drill a 7 x 8 m pattern with an average of 120 holes per pattern, although some patterns require up to 500 holes.
The large capacity of these rigs was one of the main reasons they were chosen. As Chief Mining Engineer Denis Golubnichy explains: “We liked the DM-M3 because it allows us to drill a larger diameter hole, giving us more blasted material per meter. Having four DM-M3s at work drilling these large holes has enabled us to increase our blast production.”
As part of the deal, the mine has a service agreement with Atlas Copco whereby eight Atlas Copco service technicians and one technical manager will be stationed on the site for three years. When M&C visited the mine in May this year, the service team had completed almost a year handling all rig maintenance and repairs, with the exception of the engines which are normally serviced by the mine’s personnel.
Commenting on the service, Mine Manager Zakhar Pavlov, says: “So far it has been excellent. Whenever a spare part is needed or a particular issue arises, the service technicians come up with a quick solution.”
Alexey Korobchenko is Atlas Copco’s onsite Project Manager, liaising with the mine and organizing the tasks for the service office in Kostomuksha. His main contact at the mine is Drill Site Manager Oleg Romaniko. Together they plan the maintenance schedule, operator training, discuss future plans and new equipment for the mine, and assess the status of all Atlas Copco rigs on site.
Korobchenko says: “Oleg supervises our activities and controls operations so we can meet a 100 percent work safety standard. We are thankful that Oleg has helped us with information and critiques from the customer side, which is critical for our rigs to remain productive.”
Cold weather protection
Evgeny Zhdanov, Atlas Copco’s Service Technical Manager, confirms that only a few issues have affected the performance of the rigs beyond the wear and tear that rigs of this size usually endure. With availability at around 90 percent, he says the rigs average 600 hours of drilling per month, and compared to the Russian electric drills, they are faster and give better uptime and maneuverability.
In the extreme weather conditions here during winter, the DM-M3 rigs are well protected. Thanks to a cold weather kit they are able to operate in temperatures down to –38°C. For temperatures that low, effective lubrication is essential and special synthetic oil is used in the hydraulic systems.
Exposure and constant ground contact subject the crawler undercarriage to particular abuse in low temperatures. And the base material, steel and rubber, have been upgraded for rotating of components with an articulated movement.
Others need heating and Atlas Copco has designed a series of heater packages for lubricants, fuel, engine and batteries. Today, more than 150 Drillmaster and Pit Viper rigs work in mines where temperatures can drop below –40°C.
Karelsky Okatysh is also planning ahead. The rock type in most of the pits is hard and in some places extremely hard. To help deal with this, the mine has now also taken delivery of its own Pit Viper 275 multi-pass rig equipped with Atlas Copco’s automated Rig Control System. In addition, the mine uses a number of other Pit Viper 275 rigs operated by a local contractor.
The PV-275 is designed for rotary drilling of blastholes up to 270 mm (10 5⁄8″) in diameter with bit loads up to 70 000 lbf and to a maximum hole depth of 59.4 mm (195 ft).
Mine Manager Pavlov says: “We think the Pit Viper 275 will be the best drill to use in our pits with the hardest rock, so we will start in the central pit and go from there.”
Training and expansion
In addition to a strong focus on safety, Karelsky Okatysh places high demands on operator training before allowing employees to take up positions of responsibility. For example, a driller is required to have at least 10 years’ experience before being considered a full-fledged, blasthole drill operator, known as a “6th grader” – the highest achievable level according to the Russian scale.
Exploration also plays a major role in the mining process as this is critical to expansion and to achieving continuously increasing production rates. A good example of this is the mine’s ongoing Deep Horizon project which involves core sampling at depths of 200 –250 m and will continue until 2016.
By the end of 2013, the mine will have drilled 1.4 million meters for blast and has seen its output grow from two million tonnes per employee to 2.6 Mt. By 2015, the mine expects to produce 10.7 Mt of pellets.