Abstract:The process of "a section of reduction and purification of indium rich slag" was adopted, and the valuable metal indium in the indium rich slag was recovered. The best process parameters for a period of low acid removal are: oxidant 40ml / L, endpoint pH4.0, liquid-solid ratio 5:1, and temperature 70-80℃. The removal rate of copper and zinc in indium-rich slag in a low-acid removal process can reach more than 95%, The removal rate of iron can also reach more than 55%, The indium loss rate is less than 1%; The best process parameters for secondary high acid immersion in indium are oxidant of 100ml / L, starting acid concentration of 300g / L, temperature of 80-90℃, reaction time of 2.5h, The recovery rate of indium can reach more than 95%; The best process parameters for cascade purification of iron powder are: 3.5g / L iron powder, 1.3 times of sodium sulfide, reaction temperature of 60℃, time of 80-100min, The impurity removal rate can reach more than 95%, The indium loss rate can be controlled below 5.0%.