摘要 |
<p>Compositions formed by immobilizing microorganisms or other material capable of binding metal ions; washing the immobilized metal ion-binding microorganisms; drying the washed immobilized metal ion-binding microorganisms; and heating the dried immobilized metal ion-binding microorganisms at an elevated temperature are disclosed. The compositions of this invention are stable and non-swelling in aqueous solutions having temperatures as high as 300°C or higher and in aqueous solutions having pHs in the range of less than 0 to greater than 12. The immobilized microorganisms in the compositions of this invention preferentially adsorb precious metal ions from an aqueous solution containing concentrations of base metal ions and/or other dissolved materials several orders of magnitude greater than the concentration of the precious metal ions. The compositions of this invention have been used to extract precious metal ions from geothermal fluids. The compositions of this invention have also been used to extract hard metal ions, intermediate metal ions, and soft metal ions from aqueous solutions at ambient temperatures.</p> |