Bullion lead is a product obtained by reduction and smelting of anode slime produced by lead electrorefining. 

Its main chemical component contains a large amount of rare metal such as Au, Ag, Cu, Sb, Pb, Bi, etc. in the presence of metal or alloy phase. Its gold and silver content is generally between 30-50% and has the high economic value, is the main raw material for the comprehensive recycle of lead rare metal in lead smelting.

At present, the domestic use of silver furnace fire refining to treat bullion lead. The output of alloy anode plates containing more than 90% of Au and Ag. They are sent to extract silver by electrolytic. The various oxidation are produced during the refining process which reduce the yield of precious metals.

The vacuum distillation method utilizes the difference in vapor pressure of each alloying element in the bullion lead for distillation separation.

The bullion lead is placed in a vacuum metallurgical furnace, and under the vacuum degree of 30 Pa or less, the distillation temperature is controlled at 1000-1200°C, and Pb, Bi, and Sb in the bullion lead are volatilized into the gas phase. Lead bismuth antimony alloy is obtained after condensation.The noble metals such as Au, Ag, and Cu in bullion lead are effectively enriched in the distillation residue, which is beneficial to the next step of refining.

The process of vacuum distillation method is simple, the direct yield of noble metals is good,less cost and less pollution.