Mining

R 9400 helping restore native lands

In the northwest of New Mexico, a Liebherr R 9400 mining excavator with the nickname “Bherr Claw” has been crucial to mine reclamation operations at the Navajo surface mine located within the Navajo Nation. The Navajo Nation is the largest Native American tribal nation – both in landmass and population – in the USA and its land spans three states: Arizona, Utah, and New Mexico.

The Navajo mine is owned and operated by the Navajo Transitional Energy Company (NTEC). NTEC acquired the Navajo mine from BHP Group in 2013. Officials of the Navajo Nation made this decision to protect jobs, maintain revenue, and support local economies for the Diné, also known as the Navajo people. When NTEC acquired the mine, it also inherited a significant amount of unreclaimed mining land; land that had not yet been restored for its original purpose after the mines had become exhausted. NTEC takes its reclamation responsibility incredibly seriously and has committed to reclaim well over 84 million m3 of material. Reclamation of this unreclaimed land began in 2017 and is expected to be completed by 2031.

A force to be reckoned with

Bherr Claw – NTEC’s R 9400 mining excavator – has been essential for reclamation efforts at the Navajo mine since the machine’s delivery in 2019. The 345.50 tonne excavator was the first piece of Liebherr equipment that NTEC owned outright. It is set up in a backhoe configuration and has been digging channels and doing regrade work in the mine pits. Bherr Claw is currently working in an area of the mine that NTEC has voluntarily committed to reclaim, to ensure the land is restored to its highest environmental status.

NTEC’s commitment to reclamation is the driving force behind the company’s annual increase in the amount of land it restores and Bherr Claw has helped to dramatically increase the efficiency of this process. The R 9400 is scheduled for over 80 hours per week to handle blasted sandstone spoiled by draglines and the machine plays a crucial role in helping restore the land to a sustainable and stable condition.

“The large excavator makes the job easier. We can move more yards than we can with a single loader [wheel loader], and we’re able to load more yards more efficiently into the bed of a truck,” said Virdon Yazzie, Reclamation Manager for NTEC.

Going above and beyond

Today, the Navajo mine is a mine-mouth operation, providing over four million tonnes of sub-bituminous coal to Four Corners Power Plant. However, before the land was used for mining it was primarily used for livestock, cattle, and sheep while also providing habitation for local wildlife. Restoring the area so the mining land can be used for these purposes once again is a high priority for NTEC and the company has already exceeded its expected restoration requirements. Navajo mine was built in an area that was 60% badlands – arid terrain with little to no vegetation growth. Because of this, there were fewer restoration expectations placed on NTEC, given the inhospitable nature of the original land. But NTEC is determined to leave these mining lands in the same – or better – condition than when they were developed.

Liebherr, NTEC, and Navajo mine have established a strong working relationship built on trust and an understanding of both NTEC’s and the mine’s mission to do things in the right way and to operate safely and efficiently.

“The Liebherr Group provides good responses to occasional issues with the machine and understands the criticality of this machine to our operations and NTEC’s commitment to reclamation,” said Yazzie.

A powerful reputation

One of the main reasons that NTEC decided to purchase the R 9400 was the Tier 4 engine. Tier 4 is an emissions standard set by the Environmental Protection Agency in the USA that aims to dramatically reduce the amount of particulate matter and nitrogen oxides being emitted by off-highway diesel engines.

However, another reason the R 9400 was chosen was because of its reputation for high performance. The excavator has been designed to offer the best force distribution and digging and lifting forces within its class. When NTEC operators were working to reclaim areas of dragline spoils, they realised that they needed a machine like the R 9400 to handle the tough materials buried within the land. Bherr Claw has proven its reliability in the years since it was commissioned and NTEC remains sure that the reliability and high performance of the R 9400 will continue, allowing for Navajo mine to continue its impressive reclamation efforts.