High in the mountains of northern Peru lies the La Arena open-pit mine, a combined gold and copper operation. The site sits along one of the world’s largest porphyry copper–gold belts, part of the Andean metallogenic area that has yielded many of South America’s major deposits. As of late 2024, the mine is owned by Zijin Mining.

The geology at La Arena is notably abrasive, with hard volcanic and intrusive formations that place significant stress on drilling equipment. These ground conditions make controlled blasting especially important, and the mine relies on pre-splitting to define stable walls and predictable bench geometries. Pre-splitting involves drilling a precise line of holes ahead of the main blast, creating a clean fracture plane that limits overbreak and improves overall pit stability.

Pree-splitting at La Arena is performed by Spanish company Acciona, a global infrastructure and mining contractor. Acciona uses 4” Down the Hole hammers paired with 5” bits. Because of the highly abrasive rock, tool life has been a long-standing challenge, prompting Acciona to run a series of comparative tests to identify equipment that could best withstand the conditions.

In mid-2025, Acciona invited Robit to participate in the tests. The setup included the Robit® H4 Marathon hammer with a TD40 shank, along with three different sets of drill bits. Robit’s DTH Drillmaster, Renato Castro, supervised the trial on site, ensuring proper operation, monitoring wear, and gathering performance data. The test period ran from June to July 2025.

The results were decisive. The Robit H4 Marathon hammer achieved a total service life of 4,740 drill meters, significantly outlasting the competitor, which reached 3,100 meters.

Bit performance showed the same trend. In the extremely abrasive rock, Robit’s bits averaged at 140 meters, while competitor bits averaged around 65 meters. Among the designs tested, the convex-face bit with Extreme Carbide gauge inserts delivered the best balance of durability and penetration.

Encouraged by the results, Acciona is exploring additional bit designs with Robit, including Extreme Carbide models, to further reduce cost per meter and improve productivity. The Marathon hammer has already convinced the contractor with its longer lifetime and penetration rates about 30% faster than the competing product.

For Robit, the successful trials represent a promising technical outcome – and the foundation for a potential long-term collaboration.

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