Influence of water level in mine sequencing applied to strategic mining planning

Developing mine sequencing involves a number of factors and a large amount of information, and consequently the profitability of the project will strongly depend on the production schedule. A mining project may be conditioned to non-optimal sequencing, which may affect the economic results of the project and also lead to an inadequate utilization of the mineral resources. The conventional method of mining sequencing is divided into three main steps: first, the delineation of the final pit; second, subdivision of the final pit in operational pushbacks (mining advances) and third, sequencing the blocks in each of these pushbacks, taking into consideration mine, processing plant and market capacities. However, there are some aspects that are not usually incorporated in production scheduling, including ore mining below groundwater level. The objective of this study is to demonstrate the relevance and impact on the results of the Net Present Value (NPV) from groundwater level as a constraint related to the need for its drawdown, also considering grades and Stripping Ratio (SR) variability during mining sequence for a phosphate mine. The results show a difference of U$ 140 million for the evaluation considering and not considering groundwater level, without considering other restrictions

Mine planning under uncertainty

The aim of this study is to develop a methodology that can contribute to the construction of scenarios for mine planning and to evaluation of the impact of geological uncertainties provided by simulated models. The approach suggested here includes the definition of a methodology to control and incorporate the local uncertainties associated with the ore in order to improve mine planning, assess the sensitivity of financial return and while considering the variations and uncertainty related to the geological model and grade estimation

Detección de problemas de drenaje en minas a cielo abierto y caminos de acarreo utilizando fotogrametría UAV

Open-pit mines generally have operational problems such as puddling and inappropriate water flow over haul roads, particularly if located in areas with high rainfall indices. These situations increase truck cycle times, promote rapid deterioration of haul-road wearing-course material, reduce productivity due to downtime and increase road maintenance. In addition, operational costs are raised as the frequency of truck maintenance and tire failures also increase. The use of a high-resolution three-dimensional elevation model, created based on Unmanned Aerial Vehicle (UAV) photogrammetry, has been shown to be an effective technique to detect anomalies in a fast and precise way. With the proposed approach, it is possible to diagnose haul-road conditions after rainfall or to anticipate the potential occurrence of such anomalies before they become a greater problem. This diagnosis can then be used to prioritize maintenance activities in open-pit mines. To describe the methodology, a case study is presented demonstrating and validating the results obtained.Las minas a cielo abierto generalmente tienen problemas operativos, como empozamiento y flujo de agua no apropiados en los caminos de acarreo, principalmente en minas ubicadas en áreas con altos índices de lluvia. Estas situaciones aumentan los tiempos de ciclo de los camiones, promueven el rápido deterioro de las carreteras de transporte ocasionando la reducción de productividad debido al aumento del tiempo de inactividad y de la frecuencia del mantenimiento de las carreteras. Además de eso, los costos operativos se incrementan una vez que aumenta la frecuencia del mantenimiento de los camiones y desgaste de los neumáticos. El uso de un modelo de elevación tridimensional de alta resolución, creado a partir fotogrametría de datos de vehículos aéreos no tripulados (UAV), ha demostrado ser una técnica eficaz para detectar anomalías de forma rápida y precisa. Con el enfoque propuesto, es posible diagnosticar las condiciones de los caminos de acarreo después de la lluvia, o anticipar el potencial de ocurrencia de tales anomalías antes de que se conviertan en un problema mayor. Este diagnóstico se puede utilizar para priorizar las actividades de mantenimiento en minas a cielo abierto. Para describir la metodología, se presenta un estudio de caso que demuestra y valida los resultados obtenidos

Multi-stage dumping sequence : a feasible waste management alternative for open pit mining

Waste management and environmental aspects are progressively gathering attention in the mining industry. Mine planners must deal with increasingly complex tasks to balance between ore block schedules, waste disposal, operational cost and environmental reclamation. The mine incomes are generally related to mining and processing of the ore, thus most optimization researches regarding strategic mining usually focus mainly on ore extraction. Nevertheless, waste sequencing and disposal play an important role given that, in several situations in open pit mining, waste volumes are generally larger than ore volumes and must be moved to reach the buried and deeper ore bodies. In some cases, a significant percentage of operational costs is represented by waste haulage and disposal. Thus a careful planning strategy must be considered to minimize unnecessary expenses. Selecting locations for waste dumps is also a challenge. Many operational and technical aspects must be considered, not to mention the increasingly limiting environmental constraints. This definition can be very time consuming, and if it is not properly studied, may negatively impact the mine operation during its lifetime. This article investigates a new approach for mine waste management called the multi-stage dumping sequence (MSDS), suggesting the use of temporary waste dumps along the way to the final dump destination. Although this method requires material re-handling, which is considered a paradigm in mine industry, it certainly provides additional time to design and permit the final waste dump site and, if well planned, might even result in profit increases by reducing haulage distances in the first years of operation

Consideración de la dilución operativa incorporando incertidumbres geológicas en la planificación minera a corto plazo

Operational dilution in open-pit mining can influence short-term mine planning and affect the adherence between designed and executed plans, impacting the reconciliation results. This type of dilution may occur due to several reasons, such as erroneous assumptions regarding contacts, inefficient mining performance and uncertainties associated with the planned grades. The use of uncertainties enables better predictability and achievement of planned targets. Using the mine planning polygons and grade models, a methodology is proposed to measure the dilution ranges in each region. The methodology considers the uncertainty associated with the ore grades to verify the probability of occurrence of dilution in the short-term mine plan. The results demonstrated that the use of uncertainties enabled identification of the areas with a higher potential of incurring operational dilution. Using this information, the plans can be adjusted to minimize dilution, or the result can be used as a factor to correct the planned data.La dilución operativa en la minería en rajo puede afectar la adherencia entre los planes diseñados y ejecutados, lo que afecta los resultados de la reconciliación. Este tipo de dilución puede ocurrir debido a suposiciones erróneas con respecto a los contactos, desempeño minero ineficiente e incertidumbres asociadas con las leyes planificadas. Utilizando los polígonos de planificación y los modelos de bloques, se propone una metodología para medir los rangos de dilución en cada región. La metodología considera la incertidumbre asociada con las leyes de mineral para verificar la probabilidad de ocurrencia de dilución en el plan de mina a corto plazo. Los resultados demostraron que el uso de incertidumbres permitió la identificación de las áreas con un mayor potencial de incurrir en una dilución operativa. Con esta información, los planes pueden ajustarse para minimizar la dilución, o el resultado puede usarse como un factor para corregir los datos planificados

New Methodology for Precise UAV Surveys with a Single Ground Control Point

The advances in aerial mapping using unmanned aerial vehicles (UAVs) are increasingly allowing for the surveying of areas that are difficult or unsafe to access. Considering that the cameras boarded on UAVs are non-photogrammetric sensors, positional accuracy and precision are paramount to ensuring that the final product is geometrically consistent and that its coordinates are precise enough within an acceptable range (which depends on the purpose of each application). With this in mind, this work evaluates the positional accuracy of aerial surveys with UAVs supported by the post- processed kinematic (PPK) technique for the generation of cartographic products in compliance with the Brazilian cartographic accuracy standard PEC-PCD. Furthermore, this study proposes a methodology for inserting virtual control points using coordinates adjusted and inserted into the main point of selected images, using the package of solutions for GNSS RTKLIB processing, to forgo Ground Control Points (GCPs) without loss of quality of the cartographic product. This research used a UAV from DJI (model Mavic 2 Pro), equipped with a dual frequency GNSS receiver, where positional records were synchronized with the camera’s shooting times. To validate the technique, 20 checkpoints with known coordinates were selected, and these points were used in statistical tests to assess the accuracy and precision of the survey. The orthomosaic and the digital elevation model were used as the reference for positional coordinates to be compared against the PEC-PCD standards. The results show that the discrepancy is, on average, 0.126 m for planimetric coordinates and 0.066 m for altimetry. No outliers were found, suggesting a Gaussian sampling distribution. The application of Student’s t- test indicated the existence of a small bias, suggesting the displacement of coordinates along the three axes. The chi-square test showed results below the tabulated limits, attesting to the high precision of the survey. Finally, the root mean squared error (RMSE) was lower than the standard error limit for PEC-PCD class A planialtimetric cartographic products on a 1:1,000 scale. The viability of this technique is thus confirmed

Impacto de las estrategias para incentivar el uso de la bicicleta en viajes al trabajo : un estudio de caso con empleados de la Companhia Riograndense de Saneamento

This study identifies the most valued factors for potential bicycle users on work trips and evaluate the impact of implementing different strategies to improve bicycle use. We applied an online stated-preference survey from 127 Companhia Riograndense de Saneamento (CORSAN) employees in Porto Alegre (Brazil). Then, we formulated hybrid ordered logit models to estimate the probability of bicycle use under different hypothetical scenarios. The results showed that locker rooms, bicycle parking, bike-sharing systems (bike loaner programs run by the company), training for employees in bicycle use and the presence of bike paths for access to CORSAN all encourage bicycle use. The availability of locker rooms proved to be the most important variable. The joint implementation of locker rooms, bicycle parking and bike-sharing systems (loaner programs) would increase demand by 66%. The strategies discussed in this article can easily be adapted to other contexts where there is a desire to increase shared bicycle commuting to workplaces.Los objetivos de este estudio son identificar los factores más importantes para estimular el uso de la bicicleta en viajes al trabajo y evaluar el impacto de la implantación de diferentes medidas. Los empleados de la Companhia Riograndense de Saneamento (CORSAN) fueron utilizados como estudio de caso en Porto Alegre (Brasil), a través de una encuesta de preferencia declarada. La probabilidad de uso de la bicicleta en diferentes escenarios se estimó mediante modelos híbridos logit ordenados. Los resultados mostraron que la implantación de vestuarios, estacionamiento de bicicletas, sistemas de bicicletas compartidas (programa de préstamos de bicicletas realizado por la empresa), capacitación de los empleados en relación al uso de bicicleta y la presencia de ciclovías para el acceso a CORSAN, fomentan el uso de la bicicleta. La disponibilidad de vestuarios resultó ser la variable más importante. La implementación conjunta de vestuarios, estacionamiento de bicicletas y sistemas de bicicletas compartidas (programas de préstamo) aumentaría la demanda en un 66% en este caso. Los procedimientos adoptados podrían aplicarse fácilmente en otros contextos donde se desee incrementar la proporción de viajes hacia los lugares de trabajo

Análise da sensibilidade do modelo geológico no sequenciamento de lavra

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Otimização de projeto

A mineral deposit can be exploited by underground methods or by open pit methods, defined according to their characteristics, especially in relation to depth and geometry of the ore body and the economic feasibility of the methods. However, there are cases in which the alternative that represents the best return for the project is the application of combined methods, i.e., the open pit followed by underground mining. In these situations, the major difficulty is the definition of the transition point of methods, seeking to maximize the net present value of the project and the use of mineral resources. The premature suspension of activities in the open pit, as well as advancing beyond the optimum depth, can derail the implementation of the combination of methods, so it is important to analyze the project not only individually but also in an integrated way.Um depósito mineral pode ser explorado por métodos subterrâneos ou por métodos a céu aberto, sendo tal ação definida de acordo com as suas características, principalmente em relação à profundidade e à geometria do corpo de minério e aos aspectos econômicos de viabilidade dos métodos. Contudo existem casos em que a alternativa que representa melhor retorno para o projeto é a aplicação dos métodos combinados, ou seja, a lavra a céu aberto seguida da lavra subterrânea. Nessas situações, a grande dificuldade é a definição do ponto de transição de métodos, de forma a maximizar o valor presente líquido do projeto e o aproveitamento dos recursos minerais. A suspensão prematura das atividades a céu aberto, bem como o avanço além da profundidade ideal, pode inviabilizar a aplicação da combinação de métodos, portanto é importante que o projeto seja analisado não só de forma individual, mas, também, de forma integrada

TUTO DATAMINE

Construção de vídeos interativos contemplando tutoriais autoexplicativos para aprendizagem e utilização de softwares especialistas para engenharia de minas contemplando os conteúdos de modelagem geológica e planejamento de lavra. Os vídeos explicativos terão o objetivo de substituir apostilas contendo figuras estáticas por tutorias dinâmicos apresentando de forma dinâmica as instruções para a utilização de ferramentas profissionais para Engenheiros de Minas.Para editar os arquivos é necessário um editor de textos simples, como o Bloco de Notas, ou editor específico para edição de códigos, como o gratuito Notepad++. Não use editores como Word, pois acrescentam formatação de texto ao código. Este material foi feito com PHP 4. Caso deseje visualizar o projeto localmente, é necessário ter instalado um servidor Apache pois os arquivos PHP não abrem no navegador, como no caso do HTML. Tenha em mente que um hipertexto que usa PHP provavelmente foi desenvolvido com a intenção de ser disponibilizado na internet - e não apenas ser consultado localmente, como um software instalado no computador pessoal. Sendo assim, ressaltamos que a versão do servidor web na qual este arquivo irá ser publicado é o fator mais importante - e que você, enquanto cliente que disponibiliza os arquivos para publicação não tem controle sobre isso. Sendo assim, a recomendação é que você faça os testes localmente habilitando os avisos no php.ini. Este link, do manual do PHP, indica como fazer este procedimento. http://php.net/manual/pt_BR/function.error-reporting.php Este material foi feito com HTML 4 e CSS 2. A mesma situação se repete com as versões das linguagens chamadas "client-side", como HTML, CSS e JavaScript, já também há uma dependência do ambiente instalado no computador de terceiros. Neste caso, a terceira parte não é o servidor, e sim o usuário. A compatibilidade do código que você está baixando depende totalmente dos navegadores que este usuário tem instalada na máquina dele, e infelizmente você também não tem controle sobre isso. Em relação a este assunto, tudo o que podemos assegurar a você que fez o download deste código é que ele foi testado e estava adequado à tecnologia da época em que foi produzido. Para disponibilizar o projeto na internet é preciso ter acesso a um servidor PHP. A transferência dos arquivos pode ser feita com o software gratuito FileZilla.VídeoTextoUtilizar o recurso de forma a executar todas as atividades de primeira para a última, pois os resultados são interdependentes e o conhecimento é construído de forma integrada, sendo indispensável executar o passo a passo conforme a ordem dos conteúdos