Crude chromatography column instead of mining?

Question

Please read details!

I KNOW there are faster, better, easier methods for recovering chemicals, but I’m writing fiction and this is what the story demands.

Please don’t suggest usual techniques of mining, smelting, etc.

We have a crude chromatography column with finely crushed charcoal as the filter material.

We try to separate

1) minerals in river water,
2) minerals that can be dissolved from soil by filtering additional water through it,
3) metals remaining in the ashes after burning plants grown in metal rich soil.

What elements (especially metals) are we likely to be able to recover, in what kind of quantities?

Though we have plenty time (generations) to repeat the process, until useful amounts of metals can be recovered, estimate the time it will require more precisely.

What are the more common industrial uses for the metals or compounds recovered? (Optional)

Thanks for patience, all who answer.

Confused? Ask more details, I'll provide them.

Answer 1

Minerals and metals dissolved in water will be present in the form of cations. Because of this, you will have to change the filler (better called the "stationary phase") of your chromatography column. Charcoal has no affinity for charged species; organics will bind to the surface of the charcoal, and the dissolved minerals will pass through in the water (mobile phase) freely. Even then, you will have an additional problem: since the dissolved metal atoms are charged (as cations), a chemical method of obtaining the free metal will have to be invented, since you don't want to hear about smelting.

Assuming you find such a method, a stationary phase that will separate the metal ions would be either clays (treated to avoid clumping) or zeolites. Look up "Ion Exchange Chromatography" in Wikipedia.

As for what minerals are where, since rivers run over the earth and soil, there is nothing in a river that isn't also in the soil. Also, since plants grow in the soil, there’s nothing in them that isn’t in the soil as well. The only difference will be in the relative proportions. Calcium and Magnesium will be the most abundant by far. Calcium is used as is, primarily for cements. Magnesium can be used in construction, usually alloyed. After this you will find Phosphorus, Potassium, Copper, Iron, Manganese, and Zinc in trace amounts. In fact, do the separations long enough, and you should be able to get at least some of the entire naturally occurring non-gaseous elements (up to Radium). But to reiterate, they will not be present as free metals.