Platinum is relatively rare in the Earth's crust. Platinum is a siderophile element, attracted to iron, and follows iron to the Earth's core. Only a few regions in South Africa, Russia, and Columbia have ores with platinum concentrations worth mining. 80% of global production is in South Africa.

Some asteroids may contain up to 100 grams of platinum per tonne (100 ppm), 10 to 20 times the concentrations found in South African mines. The November 2019 platinum price is $30,000 per kilogram, so raw asteroidal ore contains up to $3 of platinum per kilogram.

But platinum doesn't just hop out of the ore when you snap your fingers. The process of extracting terrestrial platinum requires vastly more inputs of materials and energy that are plentiful on Earth, but absent on platinum-bearing asteroids.

In South Africa, producing a kilogram of platinum entails:

Steps in the refining process include :

Given the enormous inputs of materials and process equipment, the end goal for asteroid extraction probably won't be pure platinum, but the concentrated output of some intermediate step above, mass reduced for more economical shipment to Earth. On Earth, clean water and air and solvents and labor and energy are abundant; they will all need to be manufactured or transported to an asteroid platinum refinery.

So, the question isn't "how much platinum does an asteroid contain?", but

The minerals buried underneath my back yard (all the way to the core) are priced at 40 trillion dollars, with PNG elements priced at 5 trillion dollars. The "delta V" to the surface is less than the delta V from the asteroid belt. The expense and effort to extract those ranges from absurd to impossible; asteroid extraction may be in that range as well.

Platinum (last edited 2019-11-20 18:40:37 by KeithLofstrom)