The Usibelli Coal Mine is located just outside Denali National Park and Preserve in Healy, Alaska, USA, and single-handedly heats Fairbanks. The mine’s production has increased steadily through the years, today outputting 1.2 – 2 million tpy of coal.
Hitachi has provided a EX1900-6, equipped with an advanced hydraulic system to provide efficient combined operations of the front attachment and swing and deliver quick cycle times. When combined with a patented auto-levelling mechanism and large bucket capacities, the EX1900-6 is able to make a large contribution to that efficient production. It helps handle approximately 50% of the mine’s production output.
Since its purchase in 2012, the excavator has been relied upon by the team at Usibelli through harsh temperatures and conditions.
A need for reliability
With a fuel-efficient Cummins EPA Tier 2 diesel engine with 1086 hp (810 kW), the EX1900-6 can handle a large workload. Advanced hydraulics, a tough frame and powerful arm- and bucket-digging forces help increase its reliability.
For enhanced productivity, Usibelli utilises a customised 15 m3 bucket. The EX1900-6 bucket is typically 12 m3. With a backhoe operating weight of 423 288 lbs (192 000 kg), the excavator offers a maximum dig reach of 50 ft (50.25 m) and maximum dig depth of 26 ft 10 in. (8.18 m).
The EX1900-6 also provides a comfortable working environment. The well-insulated, pressurised cab keeps out dust and is air conditioned.
This is important to the mine as the our operators spend a lot of time in the cab. The EX1900's ergonomics and visibility from the cab help with this.
The cab sits on a package of fluid-filled elastic mounts that reduce vibrations and deliver a more comfortable ride. Likewise, the air suspension and multi-position seat can be customised to an operator’s needs and adjusted according to operator weight.
Handling harsh conditions
The EX1900-6 features cast steel structures integrated into the centre track frame to assist in concentration, avoiding stress, and increase reliability. Contamination sensors alert the operator of accumulated contaminants in the oil that could cause damage before it is too late. Additionally, the machine features Global e-Service, an online machine management system, that provides site managers with operating information and location to increase productivity.
These machine features are crucial at Usibelli Coal Mine, where there is little daylight during winter months and cold temperatures linger through the spring. At times, temperatures plummet to as low as -60°F. Instead of hunkering down during the cold winters, Usibelli team members are hard at work. For them, it is peak season.
The middle of the winter is Usibelli's largest production time. Fairbanks is not far from the mine, and as the coldest city in the US, the coal keeps Fairbanks warm.
To streamline their mining process for efficiency and quality, Usibelli is conducting drone surveying in conjunction with the excavator. The recent pairing helped develop Usibelli’s mining process.
Drone surveying is safer and more efficient. Before, the team used GPS and had to walk around, getting to the crests by foot. Now, it can set out some control points and fly the drone, resulting in a perfect survey of the area in very little time.
With drone surveying, operators can dig in more precisely to pin-point where the ‘good coal’ is located. It is a huge help in Usibelli’s challenging environment as it is mining coal that has a parting or ‘seam’ about halfway through it.
The drone survey allows the mine to have great elevation control and hone-in on where this parting is, and where it will be projected in the future. All of this quality variation occurs within 30 ft. This helps with the excavator in these pits as it means it has been able to selectively mine the coal.
Expanding mining technology
Hitachi continues to integrate technology into its mining equipment. The manufacturer debuted the EX-7 Series in April 2019 with the introduction of the EX2600-7 and EX5600-7. The EX1200-7 was then introduced one month later in May, and the EX3600-7 was introduced in August.
With these products, customers can choose from a Cummins or maximum transition unit (MTU) EPA Final Tier 4 (FT4) engine option. For non-regulated countries, customers can choose from a Cummins or MTU engine option that features fuel consumption optimisation (FCO) settings that contribute to improved efficiency. For example, on the EX3600-7, the FT4 engine, which also has FCO technologies but uses DEF, contributes toward 4% net fluid savings while the FCO engine without DEF features a 7% net fluid savings as compared to the EX3600-6.
The EX-7 Series also provides the option of Aerial AngleTM, which works as a 360° vision system that helps contribute to jobsite safety. The system assists with noting equipment surroundings through a display monitor that combines a set of images captured by cameras positioned at different locations around the machine.
While Alex Legrismith, Usibelli Mining Engineer, anticipates the future of mining, he still expects one piece of equipment to stick around for years to come.
Legrismith said: “The next piece of equipment I would love to see here at Usibelli Coal Mine is another Hitachi shovel. I think for the mining we have coming up in the next five to 10 years, it would be perfect for us.”
When Usibelli makes that decision, they will turn to their dealer, Construction Machinery Industrial (CMI).
“Our relationship with CMI has been wonderful,” Legrismith added. “They’ve done nothing but stick by us. They are always extremely fast in getting us what we need to keep us running, and they know the community and mining industry.”
That community involvement is important for Usibelli. The company has gained brand recognition locally by giving back through sponsoring scholarships and grants to more than 80 organisations annually.
Read the article online at: https://www.globalminingreview.com/special-reports/15122020/output-management-in-alaska/
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