2. Preparation of bioadsorbents for gold recovery

The bioadsorbents for gold recovery can be easily prepared in a simple manner as schematically shown in Figure 1. Pieces of feed materials of biomass are stirred in

Figure 1. Flow sheet of the preparation of bioadsorbents.

Gold Recovery Process from Primary and Secondary Resources Using Bioadsorbents DOI: http://dx.doi.org/10.5772/intechopen.84770

boiling concentrated sulfuric acid for about 24 h, where hydroxyl groups contained in the biomass undergo dehydration condensation reactions and polymer chains of the biomass are cross-linked via ether bonds. The solid materials are neutralized using dilute alkali solution and water-washed and then, they are dried in a convection oven and pulverized. Finally, they are sieved to uniform the particle size. The final products are black powder, the particle size of which are less than 0.1 mm.
