Process introduction and process parameters:

The hot-dip galvanizing slag (the alloy of zinc-iron-aluminum) is treated by electro-thermal distillation to produce 99.99% zinc ingot or metal zinc powder. And the metal aluminum is recycled.

The vacuum distillation method utilizes the vapor pressure difference of different metals in the hot-dip slag in a pure metal state at a certain temperature. And the zinc is volatilized and condensed in a vapor state under a vacuum state, and the other impurities are not volatile or a small amount of volatile enrichment. In the residue, the purpose of separating and recovering metal zinc is achieved. Comparing with the atmospheric distillation method, this method can lower the reaction temperature, increase the direct yield (the zinc slag does not oxidize), and has the advantages of slag discharge, less labor intensity, environmental friendly, and continuous operation etc.

The process adopts vacuum distillation to treat hot-dip galvanizing slag, and electric heating to melt the hot-dip galvanized slag into zinc water and distill it under anaerobic conditions in the distillation furnace. And then it condenses to produce 99.9% liquid zinc flowing out of the casting and turn into the zinc ingot. The iron-aluminum slag produced by this distillation process contains less than 3% zinc and it can be used for cement production.

Flow chart: