As can be seen from Fig. 1 and Fig. 2, with the extension of leaching time, leaching yield of Au and Ag rising in both processes; 20h after the reaction, the leaching yields are slowing down in both the SD-0103 leaching methods and the sodium cyanide methods, indicating that the reaction has almost finished by then; yet from the perspective of reactive rate, the SD-0103 method is apparently superior to that of sodium cyanide and by the 48h after reaction, the leaching yield of Au and Ag by SD-0103 method has reached 98.94% and 53.64% respectively, while the yield of Au and Ag by the sodium cyanide method is 98.74% and 49.71% only. Obviously, leaching with SD-0103 method can result in higher yielding rate for both Au and Ag than the sodium cyanide method.

Effect of different leaching agents on the leaching yield of Au and Ag

Gold concentrate powder 200g, liquid-to-solid ratio L:S=1.5:1, adjust the pH to 12 with NaOH, filtration washing carried out 36h after cold leaching against samples dealt with SD-0103 and sodium cyanid separately, the cinder dried and cyanide leaching residue analyzed to calculate the Au and Ag leaching yield; the result is shown in Table 1.

As can be seen from the above Table, under the same leaching conditions, the Au and Ag grade in tailings dealt with SD-0103 agent drops 0.20g/t and 1.50g/t respectively compared to that of sodium cyanide method, the leaching yield of Au and Ag has reached 99.67% and 67.90%, a 0.21% and 1.09% rise from the sodium cyanide method respectively, thus it can be seen that the SD-0103 method has obvious advantage in Au and Ag leaching than the sodium cyanide method.