I am unfamiliar with Russian money.
I googled these:
The 10-kopeck coin was struck in brass-plated steel, the 50-kopeck coin, and 1- and 5-ruble coins were in cupro-nickel and the 10-ruble coin was bimetallic with an aluminum-bronze center and a cupro-nickel-zinc ring. The series depicts an image of the Kremlin on the obverse rather than the Soviet state emblem.
https://en.wikipedia.org/wiki/Soviet_ruble
Normally coins are worth more as they are, or can be more easily recognized for their value as a coin (as opposed to an unrecognizable hunk of melted metal, and can normally be more easily traded for other goods of value (as always there are exceptions)...
For example on exception, copper metal in the american penny is worth more than the coin (to date), and being illegal to melt, it can be sold as-is for a higher value than the denomination of the coin, it too (the copper penny may one day be worth more as a coin in the future than its metal content value.
Recovering a metal (such as gold or silver) from scrap material or ore consists of separating the metal from other the other metals involved and or separating the gangue material as much as possible from the desired metal, this is done using many different kinds of processes depending on materials you are recovering the gold or other metal from.
Aqua regia is a refining process, normally used on refining the recovered gold or platinum group metals, not normally used on silver or high silver alloys, aqua regia will dissolve almost all metals, using it in a recovery process normally just makes a toxic mess of metals in solution (making it even harder to recover the gold). For this and other reasons, aqua regia is normally reserved for use on a fairly clean recovered gold from the previous recovery processes, here we can take a dirty gold and remove even more of those other metals to bring the gold to a higher state of purity (and finally to a higher karat content or value when completed) up to almost pure metal.
One problem with refining gold, say recognizable coins, karat stamped rings or jewelry, is that it can become harder to sell the gold for its full value (normally buyers can only test gold up to 22 karats {22/24} and will not pay for a higher % than they can test for) where they may have paid for all the gold if you took them the rings (minus a small refining or handling fee, or their profit...
From your question I will say you will profit more by selling your scrap or coins as they are to the highest bidder or honest scrap dealer, I think I would just forget about trying to recover metal from them and then trying to refine that metal in aqua regia...
I think if I lived there, I would trade the coins for Russian electronic trash (scrap) it can contain gold as well as PGM, spend years collecting it (while studying), and then I would spend several years learning how to recover the desired metals from the scrap, and then spend another few years learning how to refine the gold successfully with aqua regia or some other process, melt the recovered PGM with silver...
:mrgreen:
