The resultant 2-stage leach process is as follows:In the first stage,"low-acid"leaching is adopted for In enriched residue,high-grade In residue is leached first by concentrated acid followed by diluted acid while in the second stage,"medium-level acid"is used for leaching.

Production feasibility exploration of low grade slag and ore of some gold mine in Burma

Chemical Phase analysis of Cadmium in Sulfuric Acid Smoke and Leach residue;