How to recover gold from cyanide solution, Learn To .
Aqua regia (often abbreviated as AR) is a mixture of hydrochloric acid and nitric acid capable of dissolving many noble metals like gold, platinum and palladium.There are a number of metals that resists aqua regia, they are titanium, iridium, ruthenium, tantalum, niobium, hafnium, osmium, rhodium and tungsten.Some alloys with high amounts of silver is also resistant to aqua regia as there .The gold will again take on the appearance of metal. If you've followed the procedure carefully and used filters, the gold should be 99.95% pure with negligible losses. Platinum. If you had platinum in your gold, it will not dissolve, to any appreciable degree, in the room temperature aqua regia.