New natural sorbent to extract metals from aqueous media

Highly mineralized waters (especially those saturated or contaminated with heavy metal cations) can serve as raw materials for metals and alloys if they can be extracted, segregated and beneficiated economically. Toxic ion removal from contaminated waters is also a major environmental and ecological concern. The most effective extraction media are ion exchange sorbent materials which may be either synthesized resins or natural deposits classed as zeolites. Obviously synthetic zeolites can be more specific but also tend to be more expensive materials. Researchers at the Mining Institute have found that the natural mineral brucite (Mg(OH) sub 2 provides extremely high sorption properties so comparative studies of brucite and three other zeolites were made under similar conditions by measuring static and dynamic adsorption capacity in mg/g. Brucite provided 134 mg/g sorption capacity from copper solutions as compared to 12-15 mg/g for the zeolites. An increase in concentration increased sorption by a factor 100X for brucite and 10X for the zeolites while fine grinding ( < =0.02 mm) increased copper sorption on brucite to 1430 mg/g while zeolites increased copper sorption to 58 mg/g. Brucite was also quite effective in sorbing zinc, manganese and aluminum (as is described and discussed in detail in this article). Mechanisms of sorption chemistry were also discussed.