High-flow metal recovery from acid mine drainage utilizing modified silica polyamine composite technology

摘要

The creation of acid mine drainage at abandoned mine sites is a worldwide problem. In many cases these sites contain significant amounts of technologically useful metals. The recovery of these metals as pure salts could help offset the price of remediation of these sites while reclaiming the surface waters that drain into them. Silica polyamine composites represent a new class of solid phase adsorbents that offer the very sharp separations required for recovering metal ions from multi-component solutions where the desired metals are present at relatively low concentrations. A combination of metal selective silica polyamine composites in combination with careful pH adjustment has been utilized to selectively recover copper(II), zinc(II) and manganese(II) from acidic metal laden Berkeley Pit lake water taken from the acid mine drainage created at the open pit mining site in Butte, MT. The purity of the concentrated solutions for these metals was 97, 99.9 and 83 percent respectively and concentration factors of 59, 11.2 and 42 were achieved. The reported data support recovery of these metals from the concentrated solutions with modern electrowhinning technology.