波兰一项专利NO137828提出了从镀金黄铜元件回收金的方法:先将镀金黄铜元件磨碎成长1～10厘米的碎粒,放入溶液中进行二段优先熔解。该溶液含有6～35％的H_2SO_4和4～10％的废硝石(40～50％NaNO_3、40～50％KNO_3、1～3％K_2Cr_2O_7)。先在室温条件下熔解20～60小时,然后在沸点条件下熔解8～ A Polish patent No. 137828 proposes a method of recovering gold from a gold-plated brass component by first grinding the gold-plated brass component into pieces of 1 to 10 cm in length and placing it in solution for preferential melting in two stages. The solution contains 6 to 35% H 2 SO 4 and 4 to 10% waste quarry (40 to 50% NaNO 3, 40 to 50% KNO 3 and 1 to 3% K 2 Cr 2 O 7). First melt at room temperature for 20 to 60 hours, and then melt in the boiling point conditions 8 ~