Zeroing in on zinc

Velardeña, Mexico: Among arid, sparsely populated hills sits Mexico’s most productive zinc mine. Every day, 6,000 tonnes of rock are hauled out of the mine, the bulk of them on 40-tonne Sandvik Mining trucks. Those trucks, and other equipment maintained around the clock by an on-site Sandvik Mining team, keep the mine moving.

In the rocky hills of northern Mexico, thickly covered with prickly desert brush, an area rich with minerals and mining history is meeting modern technology. Mexican mining company Industrias Peñoles acquired the Velardeña mine in 2005 and is now breathing new life into the region, having discovered a 30-million-tonne zinc deposit there.

A complete solution
To meet ambitious production goals for the Velardeña mine, Peñoles uses six Sandvik Mining trucks to haul thousands of tonnes of zinc out of a section of the underground mine that stretches across two kilometres and descends 200 metres into the earth. The company also uses 15 Sandvik underground loaders, seven mining jumbos to drill through rock and three rock support drill rigs to support the mine as it is excavated. On top of the equipment, Sandvik has a service and maintenance agreement with Peñoles to ensure all the machinery is constantly running efficiently. The relationship has proven valuable.

“Having the maintenance done by Sandvik, with its own mechanics, gives us an assurance of proficiency, and we don’t have to worry about the upkeep of the equipment,” says Hugo Alberto Palacios Martinez, general manager at Peñoles. Palacios Martinez oversees all operations at the Velardeña mine, and he believes the service programme is a big part of the mine’s successful operation.

About Industrias Peñoles:

Peñoles, a Mexican mining and chemicals group owned by the business conglomerate Grupo Bal, is the world’s largest producer of refined silver and metallic bismuth. It’s also a major producer of zinc and sodium sulphate and a leading regional producer of gold and silver.

Its operations include nine underground mines, two open pit mines and the refining complex Met-Mex Peñoles in the Mexican state of Coahuila. The Mexico City-based company was founded in 1887. It started operations at the Velardeña mine in May 2013, and the site has quickly become the country’s leading producer of zinc.

With its fleet of six Sandvik TH540 trucks, Velardeña is the first Peñoles mine to use the low-profile trucks.

“For us it’s something new,” Palacios Martinez says. “We’re the first Peñoles mine in Mexico using this type of vehicle. Normally traditional 20- to 30-tonne trucks are used.”

Keeping productivity and safety levels high
Because Sandvik technicians are on hand around the clock, the 40-tonne capacity trucks are always ready to haul zinc out of the mine faster, requiring fewer trips to meet the mine’s high production demands.

Upon entering the modern Velardeña mine site, the company’s commitment to safety and efficiency becomes readily apparent. Productivity is evident immediately as truck engines hum constantly and crushed rock pours continuously into a massive dome that helps reduce dust at the site as minerals are pulverized before making the trip to the company’s refining complex in Torreón.

On-site assistance
Some 200 metres below the earth, on the mine’s seventh level, Sandvik has a workshop where workers provide preventive and corrective maintenance. In contrast to some of the darker tunnels, the workshop is a brightly lit underground oasis, with even some potted houseplants adding a bit of green to the atmosphere.

“As part of the service agreement, Sandvik has three groups of about 10 technicians who take shifts working in the mine,” says Daniel Calderon, Sandvik contract supervisor at Velardeña.

Given that the mine is in constant operation, Sandvik employees are key to making sure that downtime doesn’t hold up productivity.

“We provide support service to the equipment all the time to maintain it and ensure that it’s always available,” Calderon says.

That aspect is crucial for Peñoles. “One of the challenges for the mine is maintaining its production goal of 6,000 tonnes every day,” says mine supervisor Gabriel Duran Lopez, who manages Velardeña’s underground operations.

Sandvik equipment at Velardeña

• 11 Sandvik LH410 underground loaders
• Six Sandvik TH540 underground trucks
• Six Sandvik DD311 mining jumbos
• Three Sandvik LH517 underground loaders
• Two Sandvik DS310 rock support drill rigs
• One Sandvik LH307 underground loader
• One Sandvik DS311 rock support drill rig
• One Sandvik DD310 mining jumbo

Not only do Sandvik trucks haul heavier loads than traditional ones, they also fit better and manoeuvre more effectively in the underground caverns.

Because it takes fewer trucks to carry material out of the mine to be pulverized up in the massive dome, that means fewer vehicles are spewing emissions into an enclosed space. Also, with the Sandvik crew helping to keep them running safely and efficiently, drivers have more confidence when handling the equipment.

Training expertise
“My crew doesn’t necessarily have the expertise to provide all the needed maintenance to Sandvik equipment, and for that reason it’s beneficial to have the Sandvik team on hand to tune up their own equipment,” says Luis Sifuentes Diosdado, head of maintenance, Peñoles.

That service is of utmost importance for someone like Maria Isabel Avila Torres, who drives one of the trucks hauling minerals out of the mine. “Driving a vehicle of that size was challenging at first,” she says. “And while it’s still not necessarily easy, I’m able to live up to the task with the training I’ve received.”

Safe driving in the tight confines of the mine is crucial, and knowing that the Sandvik team has provided complete service adds to her confidence.

Avila Torres’s hometown is Velardeña, the village that sits directly beside the mine, and she says Peñoles has played an important role in the community, giving people job opportunities that otherwise wouldn’t exist. “It’s very important because right now there’s no other employment,” she says.

On a global level, Mexico is among the world’s top 10 producers of zinc. Last year, before Velardeña completed its first year of production, Mexico was the world’s seventh-largest zinc producer, according to the US Geological Survey’s Mineral Commodity Summaries 2014. Ultimately, that zinc will become a key component in providing corrosion protection for galvanized steel or an important ingredient in many nutritional supplements, as the mineral is necessary for the healthy growth of humans, animals and plants.

Mining isn’t new in Velardeña, an area with deposits of lead, copper and gold, and the small village there is largely dependent on the mining economy.

“It’s been more than 400 years since the discovery of ore here, and it has been worked on in different eras, from the Spanish colonial era to the present,” Palacios Martinez says.

The mine is situated in an arid, sparsely populated, geologically diverse area in the Mexican state of Durango, just across the state line from Coahuila where the Peñoles refining complex is located.

The most important resource
Peñoles and Sandvik both work hard at Velardeña to use the latest technology to extract valuable materials from the earth in a cost-effective manner, but an essential component is people. While providing hundreds of jobs for locals who otherwise might not have one, the mine aims to create a safe working environment for those workers and reduce the environmental impact on the area.

These values are carried throughout the work of Industrias Peñoles and Sandvik, and they are clearly evident at Velardeña.

Sandvik maintenance at Velardeña

Velardeña is the first Industrias Peñoles mine to use Sandvik TH540 underground trucks, which are specifically designed to carry heavy loads and manoeuvre in tight conditions. Peñoles uses six of the trucks at Velardeña. Other Sandvik equipment at the mine includes 15 underground loaders, seven mining jumbos and three rock support drill rigs.

A key component of the Sandvik role at Velardeña is the service and maintenance agreement it has with Peñoles. The mine is in constant operation, and that means all equipment must continuously run safely and efficiently.

To ensure a high level of service, Sandvik has a roughly 40-member unit overseeing equipment at the mine. That includes three teams of technicians – two groups with 10 members and one with nine – who rotate shifts servicing the equipment. Each group has its own facilitator, and a fourth facilitator oversees the entire service agreement. In this way, Sandvik employees provide preventive and corrective maintenance to all their equipment at the mine.

In addition, there’s a Sandvik representative monitoring security, another overseeing stock and equipment and one handling scheduling, giving the company a fully operational team at the site.

Text: Dale Quinn/Photo:Joshua Drake