Use of heavy metal chelates of 2-mercaptopyridine-N-oxide to separate selected precious metals from acidic solutions

摘要

Disclosed is a process for separating precious metals such as gold or platinum from acidic solutions having a pH below about 3, which comprises the steps of: (a) adding a sufficient amount of a heavy metal chelate (e.g., zinc or iron) of 2-mercaptopyridine-N-oxide to the acidic solution to cause at least a portion of the precious metals in the solution to transchelate with the heavy metal chelate of 2-mercaptopyridine-N-oxide and then to form precipitates in the solution; and (b) separating the precipitated precious metal chelates of 2-mercaptopyridine from the acidic solution.