The recovery of valuable metals containing in the slag of jamesonite smelting in the blast furnace

A new process of recycling valuable metals containing in the slag of jamesonite smelting in the blast furnace was studied. In this process, the valuable metals such as Ph, Sb, Zn and In etc. were fumed and volatilized and enriched in the dust firstly and then the dust was leached by sulfuric acid. In the leaching procedure, Zn and In in the dust entered into the leaching solution and were separated from Ph and Sb which remained in the residue. The optimal operation conditions of the fuming procedure are as follows: the mass ratio of the blast furnace slag, coal powder and lime are 100:22: 10 respectively and the fuming time are 1.5 similar to 2.5 h, the fuming temperature is not below 1200 degrees C and the volatilization rates of Pb, Sb, Zn and In are 95%, 92%, 86% and 75% respectively. The optimal conditions for the leaching procedure are also presented: the consumption of sulfuric acid is 1.15 times of the theoretical consumption, the ratio of liquid to solid is 4:1 and the leaching temperature, leaching time and stirring speed are 90, 1.5h and 300 r.min(-1) separately. The leaching rates of Zn and In are 98.5% and 95.2% respectively. The experimental results shows that the valuable metals in the dust can be recovered and separated effectively by this process and their recovery efficiencies are as follows: Pb94%,Sb91%, Zn84% and In69%.