Huge savings with LNG and CAT’s DGB in La Herradura gold mine

One of Mexico’s biggest gold mining operations has been cutting fuel costs and emissions while maintaining the same performance, payload and productivity of its diesel haul trucks with Caterpillar's Dynamic Gas Blending™ (DGB) technology.

The mining OEM and its Mexico-based dealer, Matco Cat, have been working with Fresnillo’s Penmont division to convert its entire fleet of large mining trucks at the La Herradura open-pit mine, in Sonora.

Caterpillar’s dual-fuel DGB technology, which has accumulated 10 million hours in the oil and gas industry since 2013, works by blending lower cost liquefied natural gas (LNG) with diesel fuel, according to Cat.

Savings from fuel and maintenance can add up to millions of dollars each year. The important reduction in emissions is also in line with the Company's plan to  “produce (gold) in a sustainable manner”, said Fresnillo’s Abel Villa.

According to Steve Igoe, Commercial Manager for Caterpillar’s Gas Engine Business, the benefits of DGB technology include, primarily, a lower cost per tonne, realised through a lower fuel cost. “DGB truck operation with LNG has proven very beneficial to La Herradura, and this is why they have decided to convert their entire fleet,” he said.

“Typically, LNG is 30% lower than the price of diesel. And, on a typical fleet at a mine, that adds up to millions of dollars a year,” he said. “And the trucks maintain the ability to operate 100% on diesel.”

Cat estimates a fleet of 100 trucks spends approximately $60-70 million a year on diesel fuel. With 65% displacement to LNG using DGB, that fleet could save $13 million in one year on fuel alone.

DGB can also bring about a 30% cut in emissions compared with diesel-only operation – another important saving for mining companies looking at sustainability.

So far, La Herradura has retrofitted 31 of its 785C haul trucks and a significant number of 240-ton (218-t) 793D trucks with the DGB technology.

Fresnillo’s Villa said the operation also plans to partner with a third party to build an LNG plant near the mine to ensure a sustainable supply.