RE: Global Copper Reserves18 Mar 2024 11:15
"Glycine can leach most of the nonferrous transition base metals, specifically copper, but also nickel, cobalt and zinc. It is also capable of leaching precious metals under certain conditions - gold, silver, some of the platinum group metals, and finally lead under special circumstances. Various minerals leach at varying speeds and different chemical conditions. As an example, all copper minerals except silicates and copper that is chemically bound within iron oxides are leached by glycine. Leaching takes place at pH values between approximately 8 and 12.5, with the higher pH values being used to leach the sulphides and in particular CHALCOPYRITE. This supplies the base needed to fix the Fe that is leached from this mineral. In contrast to acid leaching, Fe, Mn, Ca, Mg and many other elements are simply not put into solution. There is no soluble unfixed Fe to deal with, or difficult solids like jarosite to dispose of."