Revista de Medio Ambiente y Mineria

Alternativas potenciales del Biotratamiento de aguas acidas en el cierre de operaciones mineras: Aerobio o Anaeborio

RESUMEN Una vez que las instalaciones mineras llegan al final de su ciclo productivo es difícil mantener el tratamiento de las aguas ácidas por métodos clásicos (con adición de sustancias alcalinas y consumo de energía) debido a su elevado costo de tratamiento, por lo que existe la necesidad de buscar la remediación de estas aguas a través del empleo de tecnologías limpias y económicas que incluyen plantas y microorganismos (tecnologías emergentes) a fin de reducir o eliminar el riesgo de contaminación ambiental del medio físico circundante. Los drenajes que se generan en instalaciones mineras abandonadas o al final de la vida operativa de una mina, pueden constituir importantes fuentes de contaminación y generar una serie de alteraciones medioambientales, como: cambio de la calidad de las aguas superficiales y subterráneas, perturbación de habitats y ecosistemas acuáticos, entre otros. En este trabajo se describirá la filosofía del funcionamiento de los Humedales (wetlands) Aerobios o Anaerobios y la metodología para el dimensionado de un sistema de tratamiento pasivo mediante humedales. Esta tecnología aporta posibilidades para inmovilizar los metales en formas no-biodisponibles, utilizando dispositivos diseñados para este fin y convertir los iones metálicos tóxicos a formas químicas más inocuas y estables. También se identificará con mayor detalle los parámetros más determinantes en el diseño y dimensionado de dispositivos de tratamiento pasivo, como: las características del agua, el área o superficie, la geometría del dispositivo, la profundidad de las celdas, el tiempo de retención hidráulica y la composición de los substratos. Para lograr un funcionamiento eficaz del sistema de tratamiento, se suele utilizar una combinación de distintos dispositivos de tratamiento, dispuestos en forma secuencial, incluyendo unidades de pre-tratamiento, tratamiento y post-tratamiento

ABSTRACT Once mining facilities reach the end of their productive cycle, it becomes difficult to maintain the treatment of acid waters using conventional methods (with the addition of alkaline substances and energy consumption) due to the high treatment costs. Therefore, there is a need to seek remediation of these waters through the use of clean and low-cost technologies that include plants and microorganisms (emerging technologies), in order to reduce or eliminate the risk of environmental contamination of the surrounding physical environment. The drainage generated in abandoned mining facilities or at the end of a mine's operational life can constitute significant sources of contamination and cause a series of environmental impacts, such as changes in the quality of surface and groundwater, disturbance of aquatic habitats and ecosystems, among others. This work describes the operating principles of aerobic and anaerobic wetlands and the methodology for sizing a passive treatment system using wetlands. This technology provides opportunities to immobilize metals in non-bioavailable forms using devices designed for this purpose, and to convert toxic metal ions into more benign and stable chemical forms. The most critical parameters for the design and sizing of passive treatment systems will also be identified in greater detail, including water characteristics, area or surface, system geometry, cell depth, hydraulic retention time, and substrate composition. To achieve effective operation of the treatment system, a combination of different treatment units is typically used, arranged sequentially and including pre-treatment, treatment, and post-treatment stages.

Limites técnicos para indicadores de desempenho na carga e transporte em mina de ferro

RESUMO O presente trabalho concentra-se na elaboração de referências técnicas locais e específicas para carga e transporte na fase de mina, contemplando macro indicadores de utilização física (UF - %) no transporte e produtividade (P -t/h) na carga, assim como seus sub indicadores de desempenho chave. Levando em conta perdas, restrições, referências técnicas e bibliografia relevantes. Indicadores de referências técnicas baseiam-se no mapeamento de gargalos e restrições de cada caso para definir estratégias e decisões a serem tomadas que levam a maiores ganhos operacionais, chamado de referência local. Através de dados históricos do sistema de despacho, condições de contorno da operação e referências técnicas o trabalho estabeleceu uma abordagem para estimar a referência local. Como produto estabeleceu metas de UF e P para o caso em questão, oferecendo percepções de ganhos na eficiência operacional considerando as restrições aplicadas. As percepções foram aplicadas à operação que apresentou ganhos significativos.

ABSTRACT This work focuses on developing local and specific technical references for loading and transportation in the mine phase, including macro indicators of physical utilization (UF -%) in transportation, and productivity (P - t/h) as well as their key performance sub-indicators. Losses, constraints, technical references, and relevant literature are considered. Technical reference indicators are based on mapping bottlenecks and constraints in each case to define strategies and decisions that lead to greater operational gains, known as local references. Using historical data from the dispatch system, operational boundary conditions, and technical references, the work established an approach to estimating the local reference. The result was established UF and P targets for the case in question, offering insights into operational efficiency gains considering the constraints applied. These insights were applied to the operation, which demonstrated significant gains.

Controle de danos em paredes finais resultantes de desmontes de rochas

Resumo Colapso de taludes representa um dos principais riscos geotécnicos em minas a céu aberto, especialmente em paredes finais, podendo manifestar-se em diferentes escalas - desde pequenas rupturas até instabilidades de grande magnitude - com impactos diretos sobre a seguranca de pessoas, equipamentos e a continuidade operacional. Este estudo realiza uma revisão dos principais modelos de previsão de danos em paredes finais decorrentes de desmontes de rocha, com o objetivo de avaliar a aplicabilidade e a eficiência de diferentes abordagens utilizadas para estimar a estabilidade de taludes finais em operacóes a céu aberto. A metodologia adotada baseou-se em uma revisão bibliográfica sistemática e na análise comparativa de modelos numéricos, analíticos e baseados em inteligência artificial, com ênfase nas Redes Neurais Artificiais (RNA), além da consideracao de técnicas convencionais de controle de desmonte, como o pré-corte. Os resultados indicam que as abordagens fundamentadas em inteligência artificial, particularmente as Redes Neurais Artificiais, apresentaram desempenho superior na previsão de danos em paredes finais quando comparadas aos modelos numéricos e analíticos tradicionais. Ademais, ressalta-se a relevancia da integracao entre técnicas inovadoras e métodos convencionais, como o pré-corte, visando aprimorar o planej amento e a execucáo de desmontes controlados em cavas finais.

Abstract Slope failures represent one of the major geotechnical risks in open-pit mining, particularly in final pit walls, and may occur at multiple scales-from minor sloughing to large-scale instabilities-directly affecting personnel safety, equipment integrity, and operational continuity. This study reviews the main damage-prediction models for final walls resulting from rock blasting, with the objective of assessing the applicability and effectiveness of different approaches used to estimate the stability of final slopes in open-pit operations. The adopted methodology was based on a systematic literature review and a comparative analysis of numerical, analytical, and artificial-intelligence-based models, with emphasis on Artificial Neural Networks (ANNs), in addition to considering conventional blast-control techniques such as pre-splitting. Results indicate that artificial-intelligence-based approaches, particularly Artificial Neural Networks, showed superior performance in predicting blast-induced damage in final pit walls when compared to traditional numerical and analytical models. Furthermore, the study highlights the importance of integrating innovative techniques with conventional methods such as pre-splitting to improve the planning and execution of controlled blasting in final pit slopes.

Los efectos biológicos de la contaminación minera en las cuencas que conforman la hidrografía de Bolivia: relevamiento de los estudios recientes

Resumen Existen abundantes estudios que caracterizan la contaminación minera en las diferentes cuencas que conforman la hidrografía boliviana. Solo algunos de ellos inciden en las consecuencias sobre los seres vivos que están en contacto con las actividades mineras. Desde hace dos décadas se han descrito múltiples aspectos de esta situación en investigaciones diversas, las cuales han crecido en número, manejo metodológico y recursos tecnológicos y en sitios específicos. Sin embargo, este caudal de información no se ha constituido en una herramienta que pueda incidir en las políticas del sector, dado que cada estudio analiza un aspecto específico de esa realidad cuya transformación requiere un enfoque integral, dada la complejidad de este hecho. Por lo anterior, en este trabajo se hace un relevamiento de los estudios recientes, mismos que han avanzado en complejidad procedimental, aunque gran parte de las conclusiones ya se conocía desde el inicio de estos emprendimientos académicos. Sin embargo, resalta el hecho de que, no obstante estas constataciones científicas, las causas y las consecuencias de esta contaminación siguieron creciendo de manera incontenible, aun existiendo tecnología que puede modificar la situación. Portal hecho, en este trabajo, además de mostrar el escenario actual sobre la contaminación minera y sus consecuencias, se plantea la necesidad de encontrar soluciones a la contradicción entre la necesidad de mantener el sistema productivo y la de conservar la vida.

Abstract There are abundant studies characterizing mining pollution in the different basins that make up Bolivia's hydrography. Only a few of them address the consequences for living beings in contact with mining activities. For two decades, multiple aspects of this situation have been described in various studies, which have grown in number, methodological approach, technological resources, and in specific sites. However, this wealth of information has not become a tool that can influence sector policies, given that each study analyzes a specific aspect of this reality, butthe transformation of which requires a comprehensive approach, given the complexity of this situation. Therefore, this work reviews recent studies, which have advanced in procedural complexity, although many of the conclusions were already known from the beginning of these academic endeavors. However, it is noteworthy that, despite these scientific findings, the causes and consequences of this pollution continued to grow uncontrollably, even though technology exists that can change the situation. For this reason, this paper, in addition to showing the current situation regarding mining pollution and its consequences, raises the need to find solutions to the contradiction between the need to mantain the productive system and the need to preserve life.

Análisis técnico, económico y ambiental de la aplicación de métodos de extracción directa de litio para las Salmueras del salar de Coipasa: Comparación entre absorción e intercambio iónico

RESUMEN En el altiplano boliviano, se encuentra el Salar de Coipasa (68°8'W, 19°23'S), considerado como el segundo salar más grande en Bolivia (2,500 km², 3,656 m.s.n.m.), ubicado al noroeste del Salar de Uyuni. El salar de Coipasa tiene mayor significancia como recurso estratégico de desarrollo para el departamento de Oruro en Bolivia. El presente trabajo de investigación se circunscribe al análisis de los métodos de Extracción Directa de Litio (EDL, por sus siglas en inglés DLE) aplicables a la salmuera del Salar de Coipasa, con un enfoque a dos tecnologías emergentes: absorción mediante sorbentes (adsorbentes) e intercambio iónico con resinas o sorbentes iónicos. Se examinan los fundamentos teóricos, la viabilidad operativa, los desafíos técnicos, económicos, ambientales, energéticos y de calidad de pureza del producto final de Litio obtenido, así como la factibilidad para su implementación en Coipasa, considerando las características geoquímicas de la salmuera. Se propone una metodología para ensayos piloto, se evalúan posibles resultados y, finalmente, se discuten las ventajas relativas de cada método en el contexto local.

ABSTRACT In the Bolivian Altiplano lies the Coipasa Salt Flat (68°8'W, 19°23'S), considered the second largest salt flat in Bolivia (2,500 km², 3,656 m.a.s.l.) and located northwest of the Uyuni Salt Flat. The Coipasa Salt Flat holds major significance as a strategic development resource for the Department of Oruro in Bolivia. This research study focuses on the analysis of Direct Lithium Extraction (DLE) methods applicable to the brine of the Coipasa Salt Flat, with emphasis on two emerging technologies: lithium absorption using sorbents (adsorbents) and ion-exchange processes employing resins or ionic sorbents. The study examines the theoretical foundations, operational feasibility, and the technical, economic, environmental, social, and energy-related challenges, as well as issues related to the purity of the final lithium product. It also assesses the feasibility of implementing these methods in Coipasa, taking into account the geochemical characteristics of the brine. A methodology for pilot testing is proposed, potential outcomes are evaluated, and the relative advantages of each method are discussed within the local context.