Hydrogeochemical Trends of the Valenciana Tailings, Mexico

This work describes water fluxes and chemistry of leachates draining from two tailings dams in Valenciana, Guanajuato, Mexico. From 2006 to 2010, water and suspended matter samples were collected regularly and analyzed. Sequential extraction was applied to solids in view of characterizing the As bearing phases. Valenciana tailings dams are a structure of 2.5 million cubic meters (Mm3) of wastes that annually receive a rain volume of 0.121 Mm3. Per year, drains account for 0.0057 Mm3 of circum-neutral, calcic-sulphate leachates with significant concentrations of manganese, iron, and arsenic. Iron and manganese oxides seem to be the principal phases containing arsenic.