Which is Better? Mining Oceans for Platinum, or Mining Asteroids?
Lets do some basic calculations to explore this:The ocean is certainly a lot closer and more accessible than the asteroids. But taking that approach is a little bit like the drunk who lost his keys in a dark alley, but decided to look for them a block away under the street light -- because the light was better. Convenience can be the crutch that prevents things from getting done.
The approximate concentration of Platinum in seawater is about 2.34E-10 grams per liter. That’s a 2 with 9 zeros before it, a very small number:
0.000000000234 grams per liter
On the other hand, lets consider how many liters of water there are in the ocean: 1.3E21 liters
That’s a 1 with 21 zeros after it, a very big number!
Multiply this together, and we end up with approximately 300,000 tonnes of Platinum in the seawater. At today’s price for Platinum (about US$1600 per ounce), this is $16 Trillion, or a $16 million million. That is a kingly sum.
Sounds attractive, right? But now we need to process all the water in all the oceans, and it’s a big task. We’re going to need to pump a lot of water, so lets get a big pump.
How about something Niagra Falls-sized?
Flow rate of Niagra falls: 5.7E6 liters per second.
It would only take 7 million years to work through all the [sea]water on Earth (if we had a pump and processing plant that big). This will certainly introduce some other problems. So, lets be a little more reasonable and say we could process 1 millionth of the ocean (1.3E15 liters) in 7 years, with a processing plant with the flow rate of Niagra Falls (still quite a challenge).
We’d then have about 300 kg of Platinum, with a market value of around $16 Million.
Thankfully, in asteroids similar to LL chondrites and iron meteorites that have been studied here on Earth, the concentration of precious metals like Platinum is a BILLION times higher than the ocean.
Conclusion: While asteroid mining is a big task, its much more tractable than processing enormous amounts of seawater! _Planetary Resources
If we had to get the platinum from seawater we could, given enough time and resources. But getting platinum and other valuable materials from the asteroids will begin to make a lot more sense, once humans have done the difficult preliminary work, and once they have established a permanent private industrial presence in space.
This is not a job for governments. The job of governments is to get out of the way, so that larger possibilities for the future of humanity can be developed. Governments would have their hands full just guaranteeing basic protections and equitable justice for their own citizens -- if they could only restrict themselves to the few justifiable rationales for governments in the first place.
More at the Planetary Resources website
Labels: space resources