Note I am no expert just some hobby gold miner who has his ideas about this.
Electrochemical series and the Reactivity series are actually two different subjects, one deals with electrochemical cells (electrolysis) and the other, (reactivity series deals with metals in solution), but all and all the series may be very similar (I have not compared them metal for metal to see how much different by the metals place in each.
As far as this working it can be possible, depending on the ore, some metals and salts or compounds of metals will go into will go into solution, with either just HNO3, or just HCl, and some will go into solution with aqua regia, some will not, even the gold PGM and other metals.
With ore, we can have compounds of metals even gold salts (tellurides selenates...), refractory ores, PGM metals, or compounds of metals, or even mixtures (gold-silver compounds ...), the list goes on as does the complexity.
we cannot just count on the reactivity series of metals totally as we are not really dealing with metals here, some (very little may (or may not) be actual elemental metals in rock.
Roasting would be the first (essential) step to any possible chance of success, this step if done correctly, could help to convert many of the metal salts or compounds to oxides.
Some ore's (depending on recovery route you chose to try could benefit in another roast in salt NaCl, which could help to convert many of the oxides to chlorides of those metals, if say your first leach would be using HCl alone, to remove as many metals as possible to become chloride ions in solution with this pre leach.
Note again some will some won't be converted to chloride in both of these processes... but it could help to swing the chances in your favor.
Some metals can cement out others metal ions dissolved in the solution, so several leaches may be needed, to even get as much of the less noble as possible.
Even before using an oxidizer like nitric with your leaching processes.
Testing what goes into solution and testing what does not go into solution could be key.
Assays would be key, on the ore before any treatment, and even during the different leaching processes, (undissolved powders could be gently heated to drive off chlorides without volatilizing values before bringing the temperature up slowly to a red hot covered roast (without much air, then further into an oxidizing roast introducing air (or even an oxidizer itself into the roast) before doing a fire assay test.
We would need not only to test what we had to begin and test what goes into solution and what does not go into solution...
Think of this as a big mess of metals and salts of metals we cannot really predict from the reactivity series (although very helpful too for us here where or what values go into solution, or where they are we would have to follow then with testing.
also what would work for one ore may not work for another, we may have to do extensive experimentation of many different processes, or even combination of processes to get anything to work, and smelting with various different chemical mixtures of fluxes may also need to be tested or tried.
We may also even need to experiment with a combination of smelting and wet chemical processes to be able to find a decent method of extracting as much values as possible from the ore...
Again a good preliminary assay would be key to first, not only to get an idea of values but also other compounds that you have to deal with before even experimenting chemically (or pyrological determination of values or constitutes) (If those are really real words or terms) :lol:
Heck, we may even have to do preliminary tests to figure out how to even assay the ore or collect it with another metal like lead in the melt...
It is not that you cannot get it to work, it is just more about figuring out what method or combination of methods will or will not work.
Mines normally have chemist whose whole job is to experiment to discover a method or to improve methods for the particular ore they are dealing with. some ore it may just work without much trouble others may take extensive research and much trials and retrials to find something that will work.
Rocks as simple as they are are not always simple.
A preliminary assay of not just metals but all compounds would help you to even begin, then I would study how others had dealt with similar types of ores and found success would be where I would begin.
Again I am just a man who can barely see (the blind) leading the blind here, so take this post for what it is worth not much (even with that grain of salt).
