Copco DM45 blasthole drill rigs for surface work and, for larger production holes, uses the Atlas Copco Pit Viper 275 blasthole rigs. To meet its produc- tion goals the mine added two PV-275 drill rigs to the four it already had.
This plan matches the Ovoot Tolgoi growth in digging and hauling equip- ment. The big excavator for the mine is Liebherr’s 996 with its 34-cubic-yard bucket and the Liebherr 9250 with 17-cubic-yard capacity. The mine uses
the Terrex MT 440PC 240-ton haul truck. It will be adding a second 996 excavator to its fleet this year and will increase its truck fleet from 12 to 22.
Unique difficulties in
drilling
Acting Mine Manager John Howlett said Ovoot Tolgoi is like any mine with the exception of what he calls “some really crazy seams.”
The largest of the seams that run through both pits is Number 5. It is about 50 meters thick near the surface, but dips at a 45-degree angle. There are multiple seams lying side by side. Exploration drilling has found seam Number 5 at a depth of 800 meters.
The Ovoot Tolgoi surface mine based its plans on a 20-year mine life, mining to a depth of 300 meters, but this could increase as coal demands rise. Future plans tentatively include going underground.
Ovoot Tolgoi General Manager Rodney Lacy said to date they have moved 8 million tonnes of coal to roughly 35 million total bank cubic meters (BCM) of overburden. Howlett
said his plan is to keep at least 1,000 holes drilled at all times. A single excavator can excavate 1,600 BCM an hour or 28,000 BCM total a shift. SGS wants to keep 800,000 BCM ready for the shovels at all times.
Mining coal in Mongolia is a chal- lenge. With the extreme temperatures and complex geological formations, Mongolia challenges even the most experienced engineers and miners. Other challenges to the drilling opera- tions are the sharp folding of the coal seams and the steeply dipping footwall. Drilling and blasting practices have been modified to allow for a stable final pit wall.
SGS found what Lacy called con- glomerates at the bottom of the pit. These areas were tougher to drill and blast and required patterns to be tight- ened for better fragmentation. This is another reason for the transition from the DM45 to the larger, more powerful PV-275. The drill’s greater pull down force penetrated the conglomerate mass with ease.
The standard burden and spacing was 5.4 by 6.2 meters for the DM45 with a 7 ¾-inch hole and 8 by 9 meters
Even though the mine is in the Gobi Desert, the mine had to deal with the challenge of ground water. Ground water often freezes in this climate, so the mine uses a dewatering unit and switched to a bulk-based explosive program.
for the PV-275 with a 9 7/8-inch hole.
The bench depth was 12 meters with 1 meter of sub-drill where needed. The PV-275 allowed double benching to help develop the wall in unstable areas.
One unexpected problem they encountered was ground water. Even though the Gobi Desert shows very little vegetation and annual precipita- tion, the mine has encountered a fair amount of ground water. Because the temperature is below freezing, wet holes freeze over. To remedy the situ- ation the mine included a dewatering unit and began a transition from pack- age explosives to a bulk-based pro- gram, bringing about significant cost reductions and greater flexibility.
Developing the mine
The mine has put together an equip- ment and personnel plan that will keep it on track. In 2011 alone added 200 employees to the Ovoot Tolgoi operation. Miners were being bussed from three of the local communities. The Gurvantes soum of Umnugobi district is the closest to Ovoot Tolgoi, just 30 kilometers away. Sivrie soum
and Noyon soum are 100 kilome- ters and 130 kilometers away from Ovoot Tolgoi, respectively. Additional employees and a few ex-patriots in lead positions were flown in from the coun- try’s capital, Ulaanbaatar, nearly 1,000 kilometers away. In early 2012 the company had nearly 600 employees, with 75 to 80 percent of the drillers
coming from the local communities. Because of its proximity to the commu- nities, the mine donates 2,000 tonnes of coal annually to them.
Having a fairly new work force also required an intensive training program. Lacy thinks the Mongolians are an independent-natured people, requiring a team approach to training as it relates
The mine added 200 employees in 2011 with miners being bussed from three local communities up to 130 km away.
The largest of the seams that run through both pits is Number 5. It is about 50 meters thick near the surface, but dips at a 45-degree angle. There are multiple seams lying side by side. Exploration drilling has found seam Number 5 at a depth of 800 meters.
to safety. From the start, each miner has to learn the basics, from radio instruc- tion to team work. Communication is a key part of the training program from the top down. Lacy said it starts with a new-hire meeting they have every Wednesday. Part of that meeting is devoted to sharing about each other’s history and family and offering the new hire a chance to do the same, said Lacy. He believed this builds a unity and camaraderie that promotes safety.
Where does it lead?
SouthGobi Sands is more than a coal exporter. In addition to the 600 to 700, 100-tonne trucks that roll the 45 kilo- meters to the China border every day, the mine is looking to the future.
In the beginning those trucks were running on a dirt road, and the jour- ney took nearly three hours. In keep- ing with its progressive philosophy, the mine immediately began building a four-lane road to offer better trans- port to every mine in the area. That includes the company’s next property, Soumber Mine, which will open up in the coming years.
Developing a mine is not enough for SGS. Management knows Mongolia’s future is mining and that, as it builds Ovoot Tolgoi, it is building the founda- tion of the industry in Mongolia. The foundation comes in the form of small business loans to companies wanting to start up mine service and support operations as well as from development of tomorrow’s miners through techni- cal school associations and engineering programs.
The mine’s engineering team is an example of the company’s success. Lacy thinks the team is top notch and is growing their skills. This will not only support the needs of the mine but also the development of the country for years to come.