Drowningbodacius,
I believe when you asked this question by the abbreviation your using of (Ar or AR ) you are referring to aqua regia.
Aqua regia, is a powerful combination of acids, the nitric oxidizes the gold so it can form a salt in solution with the hydrochloric acid (gold chloride salt), it will also form salts of most of the base metals (which you really do not base metals mixed in with your gold solution), Aqua regia will attack metals vigorously being a very powerful combination of acids, even pure gold metal that is thick would dissolve fairly quickly in this acid. this acid works well, but can be much harder for people unfamiliar with it, to learn how to use it to recover gold, removing free nitric from solution before trying to recover gold can be tricky, boil-over and loss of values are also possible, it can take a little time to learn proper methods, and how to use it properly.
AC/CL is not an abbreviation for anything but I assume your trying to ask about HCl/NaClO Hydrochloric acid and sodium hypochlorite (bleach) added to generate chlorine in solution to dissolve gold.
HCl/Bleach will generate chlorine in solution as the acid reacts with the sodium hypochlorite solution, it is this chlorine that oxidizes the gold so that it can form a gold salt dissolved in solution (AuCl3) with hydrochloric acid (HCl), this solution works fine for fine powder or foils, but would not work well to dissolve a thick piece of pure gold, it would take a longer time and large volumes of chemicals, the bleach is mostly water, and this solution is also slightly alkaline (NaOH involved), the water just dilutes the acid, making a large volume of dilute acid with little gold dissolved in solution, and the bleach also makes the HCl less acidic bringing the pH of solution towards neutral on the pH scale, but it works great when used as suggested by the forum to dissolve gold (base metals removed), as it is much easier to deal with when trying to recover the gold from solution (no nitric acid to eliminate as in aqua regia), the oxidizer chlorine is easily removed from solution with heat, or left in sun for a period of time.
HCl/32% H2O2 will also dissolve gold and some of the platinum group metals (PGM's), as does aqua regia and the HCl/NaClO does, this also generates chlorine in solution as the peroxide oxidizes the HCl acid, the chlorine generated oxidizes the gold, this solution does form a more dilute solution but with heat the excess water is evaporated (concentrating the solution and remaining acid), it also does not change the pH as the bleach does, and it will not form salts when water is driven off like the HCL/NaClO will do if heated to evaporate.
I feel each of these methods have their advantages and disadvantages; I also like to use different ones of these methods on different types of materials, trying to use their advantage to my advantage.
