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The ionic interaction model developed by Pitzer is applied to determine activity coefficient of the evaporitic Andean deposits known as Salar de Loyoques, in northern Chile. This salar is located in the Altiplano zone of the region of Antofagasta-Chile, at 4430 meters above sea level. The main characteristic of the salar is that in its center it has a borax deposit with exploitable levels of ulexita, a double borate of sodium and calcium. The solubilities of the minerals and the activity coefficients were calculated based on thermodynamics fundamentals using the software PHRQPITZ. In this context, the objective of this work was to evaluate the activity coefficients and the mineralogical sequence of the salar brines. The results indicate that the waters of the Loyoques salar´s show considerable variations both in their composition and their concentration but are slightly alkaline, and belong to the type Na-Cl-SO4. All the waters that enter this closed basin, subjected to processes of concentration by evaporation which causes the precipitation of calcite and later the samples that are closer to balance will be the gypsum and magnesite.

Este trabajo realiza un análisis al salar de Surire desde el punto de vista de la biodiversidad y sus implicancias producto del cambio climático. Como resultado se predice que los próximos años serán secos y la temperatura podría ir en aumento, lo cual afectará notablemente a la flora y fauna del altiplano. El salar de Surire es un cuerpo salino ubicado en el altiplano andino chileno, en un entorno geológico de características volcánicas. La climatología actual de aridez no permite una acumulación de agua superficial de gran extensión, y por lo tanto es posible diferenciar tres tipos principales de aguas: los aportes de drenaje, las acumulaciones de agua en la aureola pantanosa externa o “bofedales”, y las aguas del interior del cuerpo salino (surgencias termales y salmueras). Estas condiciones hidrológicas afectan factores abióticos, como anaerobiosis de suelos, disposición de nutrientes y salinidad, factores determinantes del desarrollo de la flora y fauna. Palabras claves: Salar de Surire; Biodiversidad andina; Cambio climático; Ecosistema andino DOI: http://dx.doi.org/10.5377/nexo.v24i1.593   Nexo, Vol. 24, No. 1, pp. 43-49, 2011

The sustainability of the lithium industry in Chile is being threatened by the series of environmental and social impacts occurring in the Salar de Atacama. This study is based on a review of technical and environmental reports, including the inspection processes carried out to date at the Salar de Atacama, the main lithium brine deposit worldwide. Demand for clean technologies has increased global lithium production, pressuring the production system to increase the quota of brine extraction to satisfy the greater demand for this resource. As a result of the extraction process in the salt flat, millions of tons of water are removed from the system in an arid region, the biota is affected, and natural conditions change in this fragile and dynamic ecosystem. The impact on the salt flat not only translates into loss of water, but also in the disappearance of vulnerable species that only exist in these places, the loss of the cultural heritage of indigenous peoples, the losses of millions of years of evolution of adaptation processes of species, including the extremophilic organisms. From the economic point of view, although both companies are committed to compensating the damage to the Atacameñas communities, one with 3.5% of the value of sales and the other with a contribution of US$15 million annually, it is not comparable with the deterioration of the Salar and the loss of cultural heritage. In conclusion, it is verified that the lithium mining industry causes strong environmental and social impacts, so we cannot speak of lithium as a synonym for "green economics." Therefore, can the lithium industry be considered of strategic relevance to the development of zero carbon technologies?