The world of mining is a world of monsters. Monster trucks with wheels the size of houses make highway dump trucks look like tinker toys. The tires alone are the price of a house. Production depends on conveyances that lift ten tons at a time and drop 40 people thousands of feet in minutes. They are supported by cables thicker than a horse’s tail and driven by electric motors the size of trucks. They run over sheave wheels the size of small Ferris wheels.
Above ground, the Sudbury Superstack is the second largest industrial chimney in the world. Eating into the surface, Chile’s giant Chuquicamata Mine is a pit 4.3 km long, 3 km wide and over 850 metres deep. The TauTona Mine in South Africa goes down 3.9 kilometres.
Size matters. In a world hungry for resources, the ability to move huge volumes of ore cheaply is the key to global growth.
For underground mines, the shaft is the great bottleneck. How do you move huge machines to the workface when the machines are bigger than the shaft? Today, you cut them up, put the pieces on the lift and weld them back together at the bottom. When the machine wears out, you shove it in a hole and cover it up – it costs too much to retrieve these monsters from the depths.
There is an opportunity here for an equipment manufacturer or a supplier to come up with a lego-like machine that snaps together. It would cut the real cost of operating the big machines in half. Why assemble the machines above ground at all? Why not take a lesson from Ikea and provide a package of parts and easy assembly instructions?
The shaft is a bottleneck for taking ore out as well. How can you move huge volumes of ore up a narrow hole in the ground? You load it on a little “skip” -not small by normal standards, but tiny by the standards of the mining industry. Loading and off-loading is costly – the fewer times you handle the ore, the lower your costs. The bigger the skip, the fewer the trips.
Vale’s planned super shaft is one solution. A much bigger shaft will provide access for the biggest machinery. Bigger skips will mean fewer trips and less handling. Building monster shafts won’t be economical for every mine, but there will be more and more of these invisible monsters in the industry.
Monster pits or monster shafts – which will we see more of? Think of it as a kind of evolutionary race. There will be more surface deposits found, but in the long run, the industry will have to go deeper to find the same grades of ore. On the other hand, as refining processes get more efficient, it may be possible to extract ore from lower and lower grades. It is far cheaper to run and care for a fleet of monsters on the surface than at depth. But lower grades mean more waste, and take more energy to process. Lower grades mean bigger holes and more environmental impact.
In the end, the race may go to the small. Research on biological, in-situ extraction may let us pump bacteria into deep blast fractures and then pump semi-refined metals out. Mining would become drilling, blasting and pumping. The long drive to cut the underground workforce would reach its natural end. Maybe the germs would unionize.
For precious metals and rare earths, the smaller mines are likely to remain economic. Equipment that can produce high volumes in narrow veins will play a big role in many new mines. These machines will not be monsters. They may actually need to be geniuses – able to make decisions in places that the operators can’t get to and can’t see.
For the supply industry, the story of the monsters holds some lessons. Monsters are built by big companies as a rule. We will see more consolidation. Monsters are increasingly run by computers, so we will see more electronics firms and programmers supplying the industry. These changes are underway and they are happening quickly. Even so, for the foreseeable future, there will be a huge stock of older mines to service and improve.