An unmanned miniature helicopter and something that looks like a small flying barbecue are among the gadgets turning the mining sector into an emerging frontier in the commercial use of drones, and at a fraction of the costs of piloted craft.
Aero experts and mapping geeks pitch remotely controlled aircraft as a cheaper and safer way to map deposit sites and even explore for minerals than traditional methods.
"They are really safe, easy to use, lightweight. You can put them in a small bag and take them everywhere," said Olivier Kung, co-founder of Switzerland's Pix4D, which makes software to convert photographs from the smallest drones into usable data.
Ranging from overgrown model airplanes to tiny, wasp-like helicopters, drones are gaining appeal as mining companies are forced to write down assets they bought during boom times and executives say they are committed to getting control of their costs.
Governments are loosening restrictions on the commercial use of drones. U.S. regulators, for example, are preparing to open their tightly controlled airspace to unmanned aircraft operated by private companies in 2015.
Mike Hutt, who heads the unmanned aerial vehicles project office for the U.S. Geological Survey, said mapping with drones can be much cheaper than traditional aerial surveys.
"It may cost $2,000 an hour to rent a helicopter," he said. "Our costs for sending a couple of operators out with a system is under $200 an hour."
Mr. Hutt's office has run all kinds of pilot projects, monitoring mine reclamation work, finding forgotten mine entrances – a major safety hazard – and locating underground coal seam fires in West Virginia, Colorado and Montana.
British Columbia's Accuas Inc. was one of several drone-related start-ups working the crowds at the Prospectors and Developers Association of Canada convention in Toronto this week. Accuas builds detailed, three-dimensional maps using its drones, also known as unmanned aerial vehicles, or UAVs.
"I would say starting a year ago, there's been a really big push on UAVs," said Scott McTavish, the president of Accuas. "I think it's going to continue to grow."
Accuas, which started out mapping landfills, now works for engineering firms, gravel producers and oil and gas companies. It started pursuing mining clients in earnest last year, after buying better equipment. Since then, its projects have included mapping for Anglo American PLC in British Columbia.
Precise maps of open pits can help in planning mines and monitoring the angle of slopes, a key safety concern because of the risk of rock slides. Drones not much heavier than a laptop computer can take measurements otherwise usually made from the ground, without putting extra workers near dangerous heavy equipment on an active mine site.
Pix4D, the Swiss software company, is growing quickly – from about five employees a year ago to 13 now. Mr. Kung said that growth is being driven by the mining industry.
He said he has already worked with most of the world's major mining companies, including Rio Tinto PLC. The big companies' research departments are experimenting, but a larger part of his business is with small surveying companies.
Some aerial mapping can be done with satellites or from conventional aircraft, but low-flying drones can collect more detailed data, often just using a camera, and because they fly below the clouds, there is no need to wait for a clear day.
The next frontier for drones in the mining business may be exploration, the search for new mineral deposits – something that is now typically done with helicopters or small planes.
Marc Goossens, who does mapping and exploration work around the world with his companies Geosense and Ursus Airborne, added small UAVs to his toolkit about three years ago. He also uses ground-based sensors, and conventional aircraft.
"It's much cheaper technology, much higher mobility, because you can carry the equipment in a suitcase," he said. "You're much more flexible."
Using a laser-based sensor to survey a square kilometre could cost about €10,000 ($13,500) with a manned aircraft, Mr. Goossens said, or €2,000 with one of his UAVs.
The problem is that many inexpensive drones are too small to fly long distances, or carry magnetic sensors, an important tool in exploration. That's where a Canadian company called Stratus Aeronautics comes in.
Buddy Doyle first started following UAV technology in the 1980s. As a geologist, he was looking for cheaper ways to collect data so that he could afford to do more drilling.
He started Stratus's predecessor, Universal Wing, in 2004. In 2007, they flew a small survey at the Diavik diamond property in the Canadian Arctic. But in those harsh conditions, their military-grade drone did not perform as hoped: "It didn't like landings," said Mr. Doyle. So they designed and built their own.
With sensors on each wing, the aircraft, with a maximum weight of about 55 kilograms (120 pounds), can fly magnetic surveys.
"The idea is to be an airborne data collector, best and least-expensive, and that's what we're doing," Mr. Doyle said. "The biggest hurdle, I would say, is regulatory."
That's a common refrain. In the United States right now, only public agencies can fly drones. In Canada, operators must apply for regulatory waivers. In many countries, regulators insist that drones stay within sight of operators on the ground.
That may not hold back site-mapping jobs like the ones Accuas does, but it's a big problem for extensive exploration. Mr. Doyle said Stratus is working with Canadian regulators on technological safeguards for long-distance flights, and he's optimistic that they will be allowed to fly their drone longer distances.