Using performance indicators to evaluate an environmental education program in artisanal gold mining communities in the Brazilian Amazon.

The Tapajos River Basin in the Brazilian Amazon is the location of one of the largest concentrations of artisanal and small-scale miners in the world. Today, 40,000 miners produce 8 t of gold annum(-1) and at least double this amount of mercury is released into the environment. This region was selected under the Global Mercury Project, a United Nations program that aims to reduce the environmental and health impacts caused by mercury through the application of cleaner technologies and increased awareness.

Biomining with bacteriophage: selectivity of displayed peptides for naturally occurring sphalerite and chalcopyrite.

During mineral processing, concentrates of sulfide minerals of economic interest are formed by froth flotation of fine ore particles. The method works well but recovery and selectivity can be poor for ores with complex mineralogy. There is considerable interest in methods that improve the selectivity of this process while avoiding the high costs of using flotation chemicals.

Role of background ions in guar gum adsorption on oxide minerals and kaolinite.

Adsorption of guar gum onto alumina, titania (rutile), hematite, quartz, and kaolinite was investigated as a function of pH, ionic strength (from distilled water to saturated NaCl and KCl), and the type of background electrolyte (0.01 mol/L LiCl, NaCl, KCl, and CsCl). It was demonstrated that the adsorption density of the polymer does not depend on pH for any of the tested minerals, so only hydrogen bonding was identified as the dominant adsorption mechanism.