Where nature meets heavy industry
In less than 10 years, an old-fashioned mine in the heart of Bulgaria has been transformed from an unprofitable health and safety hazard to a state-of-the-art underground operation. Since then, it has tripled its output as part of a modernization programme based on the latest technology and processes.
It looks like a picture postcard. Sheltered by the Balkan mountain range, the Chelopech copper-gold mine is tucked into a luscious green valley surrounded by gently rolling hills and forests and overlooking a small lake. At the entrance are manicured gardens, with no trace of belching smoke and minimal noise. Health and safety procedures have been rigorously enforced. Employees earn double the average Bulgarian salary, and rusty equipment has been replaced by cutting-edge technology.
The transformation began when Canada-based Dundee Precious Metals Inc. (DPM) purchased the mine in 2003. DPM wanted to improve efficiency and turn it into one of the most modern mines in the world, ramping up annual ore production to 2 million tonnes.
Location: 70 kilometres east of Sofia, Bulgaria, on the main route between Sofia and the Black Sea port of Bourgas.
Operations: Underground mine extracting copper-gold ore. The copper concentrate, which also contains gold and silver, is transported by truck and rail to Bourgas for shipment to DPM’s Tsumeb smelter in Namibia for further treatment. A gold-in-pyrite recovery project is currently under way to improve the recovery level of the gold in the mined ore.
Size: Production ramped up from 550,000 tonnes in 2003 to 1,813,633 tonnes in 2012.
Owner: Canada-based Dundee Precious Metals (DPM) Inc. DPM also owns the Kapan gold, copper, zinc and silver mine in southern Armenia and the Tsumeb concentrate processing facility in Namibia, and it has an exploratory project at Krumovgrad in southeastern Bulgaria.
History: Started extracting copper in 1954; purchased by DPM in 2003. Embarked on an extensive transformation project in 2004 to turn the mine around. Invested more than 500 million US dollars in upgrading the operations and about USD 12 million in the development of the local communities. Sandvik’s Trans4Mine was one of the steps to drive the transformation process. The modernization project included the installation of a new underground crushing and conveying system, upgraded mine ventilation system, a new paste fill plant, a new semi-autogenous grinding mill and the modernization of the existing concentrator.
Employees: About 1,000.
“As a relatively small player in the mining world, Dundee Precious Metals’ management believed you had to be innovative and find ways to do business better than the others,” says Nikolay Hristov, the mine’s general manager. “We said at Chelopech that we would do everything possible to succeed.”
The transformation plans were complicated by the administrative challenge of operating in a country burdened by the legacy of rules from the previous regime and changes brought about by Bulgaria’s entry into the European Union in 2007. On the operational side, the relatively high arsenic content in the Chelopech copper concentrate made it challenging to find a market. Since 2010, the concentrate has been shipped to DPM’s smelter in Namibia for further treatment.
To start with, the transformation team looked at the latest technology on the market and how it could be adapted to the underground environment. Real-time reporting and technology would optimize operations.
To enable this, the first step was to install a wireless network throughout the mine. Starting in 2009, it became possible to track the location of people and vehicles, increasing safety and efficiency.
“From this point on we could look at connecting machines, people, voice communication and data transfer,” Hristov recalls. “This is where Sandvik kicked in alongside other partners. We had a great vision. However, to make it happen we needed partners with the same appetite for challenges and taste for efficiency. Sandvik helped us to conduct audits to benchmark ourselves against others and to identify the gaps of a modern mine.
“Our mine was years behind time, and we had to bring it back to reality. That meant everything – the reliability and utilization of the machines, optimization of our processes and communication, which can be challenging as the mining industry tends to work in silos.”
The next issue was to change the mindset about planning. “We had to convince everyone that it is possible for a mine to plan and schedule everything down to the task level,” he says.
The previous materials-handling system was unable – and too old – to handle the increased output. A new underground crushing system was installed in 2012 to handle 2 million tonnes of material per year. A four-kilometre-long conveyor belt running along the Chelopech mine’s second decline to carry the crushed material to the surface was added the same year. Both were supplied by Sandvik.
Driving down the two-kilometre-long ramp into the mine, it’s clear what DPM’s CEO Rick Howes meant when he said the company was “taking the lid off” by making operations in underground mines as visible and well controlled as those in open-pit mines. Most of the underground mine is a wireless secured area, and the modern, remote-controlled ventilation provides a good work environment. The cutting-edge equipment provides safety and comfort for the operators, and everything is clearly marked, making the mine look like a model of good housekeeping.
Sandvik at Chelopech
Sandvik opened an office on-site at Chelopech in 2006 to offer the mine a faster, more flexible service to cater to Chelopech’s ambitious growth and modernization plans. Around 70 percent of all mining equipment at Chelopech is supplied by Sandvik.
Mobile fleet: Almost the entire mining fleet at Chelopech consists of Sandvik vehicles: seven 50-tonne underground trucks, seven LHDs, four Solo production drills and three Axera D07 development drills.
Service agreement: Covers the relationship between Sandvik and Chelopech since 2004, including benchmarking, transfer of knowledge and know-how and store availability.
Fixed equipment: The new underground crusher and four-kilometre-long conveyor belt from Sandvik were installed in 2012. Other equipment includes rollers and trimming machines.
Software and automated systems: Sandvik’s OptiMine remote monitoring system was installed on all trucks and LHDs in 2012. This enables the flow and storage of all data and information, making it accessible for other applications, and offers some basic reporting capability. Sandvik’s partner Geovia’s InSite solution was chosen by Chelopech for its mine production management solution. This is a platform for common production reporting and analysis, as well as for shift monitoring and management (Central Monitoring and Control System for the mine).
Chelopech’s management realized that it couldn’t achieve its dreams alone. “I believe in partnership,” says Hristov. “You want to be able to say to your partner, ‘Look, this is my problem’ and be heard. Sandvik believed in our vision and wanted to help us. We really appreciated that.”
As Sandvik already supplied all the vehicles used in the mine, equipping them with OptiMine and InSite (from its partner Geovia) was a logical next step.
Truck operator Georgi Slavchev has worked at the Chelopech mine for 10 years, and he says his job is better since the introduction of the new software. “I prefer this way of working,” he says. “It’s much less paperwork.”
Instead of keeping track of his work on paper and handing it over at the end of his shift, he now simply logs on to system in his truck, completes his tasks electronically in real time – the results are instantly fed to the control room upstairs – and logs off seven hours later.
Georgi Atanasov, the mine’s underground mobile equipment supervisor, has worked for both Chelopech and Sandvik. He says his major task, and challenge, is to avoid maintenance surprises and improve the allocation of regular maintenance activities.
“With OptiMine we can check the technical condition of the equipment,” he says. “For example, overheating is a common problem, so we get an alert, which means we can troubleshoot and solve the problem before it escalates.”
Integrating the systems was important. “We integrated the relevant systems so that the right information gets to the right people at the right time,” says Anna Ivanova, director of business systems for Dundee Precious Metals. “We really got down to the processes, incorporated them into systems and made the systems work together.”
Besides offering round-the-clock support, sharing best practices is important in an often conservative industry like mining.
“Sandvik leverages on the fact that they are a global supplier, and via their networks and forums they put us in contact with other people in the global mining industry,” Hristov says. “Through their forum we visited automated mines in Scandinavia, which helped us piece by piece to visualize how things work in different ways.”
The experience at Chelopech has benefited both parties. “It’s always nice to have this kind of mine as a partner,” says Taina Heimonen, business development manager for mine automation at Sandvik. “It’s more than just a normal business relationship as we share the same vision and passion to see how we can take that extra mile together. I believe some of the best practices here will certainly be taken further.”
Vesselin Kandarashev, Sandvik’s territory manager for South EU, agrees. “Customers like this are important for Sandvik as we share the same journey in innovation wanting to be pioneers.”
Today, Chelopech is a reformed mine. Water usage in operations has been reduced by 60 percent. CO2 emissions have been decreased by reducing transport journeys and putting the crusher underground, compensating for the increased production output. Modernizing the mine and process plant has decreased the volume of waste on the surface by 30 percent, reduced electricity consumption by 25 percent and cut fuel usage by up to 70 percent. The railway line is currently being upgraded to eliminate truck transport.
What’s the next step? “It’s difficult to read the future, as I don’t know what challenges tomorrow will bring,” Hristov says. “But let’s just say that we are not done yet. We got to 2 million tonnes of ore per year, and nobody believed we could reach that. Now we need to continue on this basis for the mine’s life and find new ways to squeeze more efficiency out of the process.”
Back outside in the warm sunshine, three vintage Sandvik vehicles are parked alongside two brand new Sandvik loaders that will soon go into operation. Out with the old and in with the new as the journey at Chelopech continues.
Bulgaria’s mining industry
Mineral exploration and mining were important under the communist government in Bulgaria, resulting in a well-qualified labour force. However, Bulgaria’s mining industry has declined since then. Many deposits are underdeveloped due to a lack of modern equipment and low funding. The industry is estimated to be worth around USD 760 million and employs around 120,000 people, making it one of Bulgaria’s most important sources of export earnings and a significant contributor to economic growth.
Bulgaria has deposits of iron, manganese, ore, coal, lead, zinc and gold. Several of Bulgaria’s minerals are extracted commercially, and 80 percent of the mining is done by open-pit excavation.