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Comment by Z1nfandel | Hacker News Reader

I thought the same, but then it made me wonder how many mines are built such that you are hauling ore down instead of up?

I don't know enough about mines, and googling "most common mine design" isn't cutting it. Could anyone weigh in with more insight? The only big mines I've seen look to be pits, like the Bingham Copper Mine near SLC.

I do remember reading something about ore trains in some Scandinavian country using regenerative braking to power nearby towns and its own trip back up.

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Here is a coal mine in Alberta [0]. If you turn on the 3D google maps, you'll see that it's at the top of a mountain. They transport the coal down into the valley and then onto rail cars.

0- https://www.google.ca/maps/@49.6515022,-114.8604751,14053a,3...

It's fairly common in West Virginia, google 'mountain top removal' for plenty of examples. EX: http://appvoices.org/end-mountaintop-removal/before-after/

The two most common types of surface mining are strip mines (where there isn't much up/down climbing) and open pit mines (where the loaded portion is going up). It's possible the mine in question is an open pit mine where your loaded descent to the dump site distance > the loaded climb distance out the open pit.

I came across this the other day while randomly reading about energy storage techniques, initially piqued by pico-scale hydro: http://www.aresnorthamerica.com

They use electric locomotives and traincars full of rock, along with a big hill, as energy storage. Drive it up during cheap energy times, and back down when you need to produce electricity.

Unless they are using this dump truck to fill in an old pit it doesn't seem like that should happen very often.

The logistics of feeding the power back to the grid are also a bit wonky. Is it going to be dragging a cable behind it? Is there an inductive charge/discharge pad that it drives over? The article has no useful details on this, and the whole idea seems rather half baked.

Doesn't an electric train have overhead power cables?

Depends on the system.

> An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or on-board energy storage such as a battery or fuel cell.

https://en.wikipedia.org/wiki/Electric_locomotive

Why would feeding power back to the grid be any different from charging? When the battery gets full you'd plug in and mostly discharge it.

I think that's a little unfair. I'm sure they've done the maths since they're building a massive electric truck. Maybe the article was overstating it a little but it certainly not technically impossible for it to store electricity and then release some of it once it's back up the top.

Think about it like this: mountains are places where deep mineral layers are pushed up into the surface, exposing them. It's where you find many of the dense, valuable ores without layers of dirt and non-valuable rock overtop. Mountains are actually great places to mine.

It depends what you're mining, is the obvious answer.

The example in the article was a cement factory - cement is basically made from limestone, and you can find mountains of the stuff. In general, you're probably looking at sedimentary deposits that have been uplifted - coal was another example someone else gave, you can probably also find mountaintop salt mines.

In either case you are probably expending way more energy digging and mining the coal such that the hauling is negligible.

Moving away from coal would have a much greater positive environmental impact than engineering the hell out of the hauling efficiency. Like wind power, solar power, hydro power, for instance, all of which don't need any hauling once built.

The Bingham actually has a conveyor works lower in the pit that goes through the side of the mountain to the processing plant.

At least it did when I was there, this was before the big collapse there a few years ago...

I have the same speculation as you -- the only use of dump trucks I've ever seen is to haul stuff uphill. Maybe it's different in some parts of the world, if anyone can weigh in.

They could almost certainly build a conveyor since anywhere they have a road they pretty much have a suitable slope. However depending on how the mine is used the top end might be moving around a lot and need to be rebuilt frequently where a truck can simply go to where it is needed as that changes. It may also make more sense to run the truck all the way down and back then to run the truck over to the head end of a conveyor.

Edit: autocorrect

Any mine that is at a high altitude relative to where the ore is taken. Even if you have to move the ore up a bit to get it out of the mine, then there is a long trip down.

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