Abstract Small and medium-sized mining represent an important part of a country's min eral economy. These companies, although substantial and numerous, have low invest ment potential in their development through new technologies. One of the problems small and medium mining companies face is the ore hauling production monitoring. This operation alone can constitute as much as 60% of the mining operating cost, due to intense fuel and tires consumption, and represents more than a half of the greenhouse gas emission in a quarry. Aiming at this problem, this article purposes to answer the following question: Is it possible to monitor the production of the ore hauling in small mining with a low-cost system? The results showed that yes, it is pos sible, using off-the-shelf solutions, regular office software and low use of labor. The results were validated in a quarry located in the State of São Paulo, where a US$ 490 system presented consistent results, improvements in fuel consumption and benefits to the environment.

Abstract The current economic and political scenario in Brazil has allowed small, medium and large companies to adopt cost cutdown and productivity increase strategies. Diesel fuel consumption by off-highway haul trucks stands for one of the largest costs at the Sossego Mine operational management department. Based on this fact, as well as on the 8% increase in the budgeted diesel fuel cost for 2017, the mining unit has decided to implement a project, previously implemented at the Capão Xavier mine site, which makes use of a high-fidelity haul truck simulator for operators' qualification, by working on the major factors impacting fuel consumption. The application of the simulator has been observed to be a potential upturn for the identification and correction of major failures and bad habits impacting fuel consumption. The results suggest a significant diesel fuel consumption cutdown, as well as enhanced haul truck operation ability and performance.

Abstract This research proposes a new approach to recommend a responsible mining guideline on how to secure a social license to operate in Ondo state, Nigeria for oil sands mineral resources taking into account the bituminous natural effects. This is the case of bituminous oil sands in Southern Nigeria, where warm weather can induce the emission of natural bitumen fumes. Because this emission may bring occupational exposure to the local communities, mining is perceived to be an opportunity for both social-economic improvement but also an efficient approach to reduce exposure to bitumen fumes. The study investigates the importance of the perception of the society about responsible mining practices in establishing a social license for a mining operation. The results of the investigation include an appraisal of the social status, living conditions of the communities, effects of pre-mining activities and the natural impacts of bitumen from oil sand on the community. The conclusions are that the bituminous natural effects on the communities can facilitate the approval of SLO, if the company can fulfil its promises, as mining is perceived to be a welcome solution to the problems posed. In addition, the mining company must also be transparent with the community as this changes the perception of society about responsible mining practices and help in establishing SLO.

Abstract A significant cost in the operating budget of most mining operations arises from purchasing and maintaining haulage trucks. Recently, in-pit crushing and conveying (IPCC) has been subject to research because of its potential to reduce haulage costs. The objective of this study is to identify early on in a project, by means of a decision-making method, whether or not the semi-mobile IPCC (SMIPCC) is an appropriate alternative to the conventional truck haulage method on the loading and hauling approaches. This method is based on cost analysis and the evaluation of environmental impacts, being successfully tested at an existing open-pit mine, where the results indicated that the IPCC was the most cost-effective option for the operation. Although the IPCC's initial CAPEX was 60% higher than the conventional approach, the IPCC's OPEX was 43% lower, resulting in a 28% reduction of the life-of-mine net present cost (NPC).

Abstract The strategic mine plan is a crucial step for the success of mining companies, and for its development, it is necessary to use a number of inter-related variables that are usually estimated independently. These variables include operational data that is traditionally isolated in information islands between the different departments in the mine or they are consolidated into individual models. This reduces the holistic view of the deposit, thereby causing a negative impact on the results of the strategic planning itself. In order to improve the process and to maximize the production and/or value of a mining project, there needs to be an integration of the geology, the mine plan, the processing and the geometallurgy data. In order to accomplish this, a new methodology is proposed for the creation of a technological model. This model can be interpreted as the consolidation of the different models required for a better understanding of the geological and technical information of the deposit. This concept was developed and applied at a copper and gold mine site located in Brazil. Based on the evaluation of different blasting and mill productivity scenarios through a pit-to-plant approach, it was possible to obtain operational short-term gains such as a 10.7% increase in the plant production rate and a 2.2% increase in the crusher's feed rate with little or no capital investment.

Abstract The use of dynamic simulation is technically advantageous for the project as shown by various authors. However, is it economically advantageous in the early stages of the project (FEL1 and FEL2)? The methodology to economically evaluate the use of dynamic simulation considers the time and development cost compared with the time and cost spent to change the project in the next phase, considering changes that could be avoided with the use of dynamic simulation. Five process plant projects were evaluated, each one with an estimated CAPEX of US$ 300 million. The saved average is US$ 44,200.00 and US$ 182,400.00 for FEL 1 and FEL 2 respectively. The percentage cost savings for FEL2 (2.0%) and FEL3 (3.1%) are significant. The estimated delay avoided for FEL2 (3 weeks) and FEL3 (8 weeks) is directly related to the implementation delay, whose cost is expressively greater than the savings shown. The study concludes that the use of dynamic simulation is economically advantageous for the project.

Abstract In the early stage of front-end studies of a Mining Project, the global availability (i.e. number of hours a plant is available for production) and production (number of hours a plant is actually operated with material) time of the process plant are normally assumed based on the experience of the study team. Understanding and defining the availability hours at the early stages of the project are important for the future stages of the project, as drastic changes in work hours will impact the economics of the project at that stage. An innovative high-level dynamic modeling approach has been developed to assist in the rapid evaluation of assumptions made by the study team. This model incorporates systems or equipment that are commonly used in mining projects from mine to product stockyard discharge after the processing plant. It includes subsystems that will simulate all the component handling, and major process plant systems required for a mining project. The output data provided by this high-level dynamic simulation approach will enhance the confidence level of engineering carried out during the early stage of the project. This study discusses the capabilities of the approach, and a test case compared with standard techniques used in mining project front-end studies.

Abstract Organizations can establish a value-added sustainable strategy by increasing asset utilization. WLAN infrastructure in underground mines tends to be a consistent platform for reliability in data/information management, and assertive governance practices. It enables remote monitoring, registering and data transfer from a control room, avoiding unnecessary human exposure in risk zones while adding agility to operation and maintenance related processes. A series of challenges must be considered so that onboard electronic systems combined with information technology infrastructure can become part of the operational strategy. Leaders must effectively manage to adapt organizations to new standards. This study aims to discuss the challenges related to implement information and automation technologies in an underground mine in Brazil. Data collected in a base metals underground mine is the basis for utilization, reliability and productivity analysis of computerized drilling equipment operating under severe conditions. The study concludes that searching for state-of-the-art operational practices demands a cultural change in organizations, followed by a redefinition of peoples' roles and processes, so technology can provide full integration and be used as a management platform for decision-making.

Abstract This paper presents the results of the application of geophysical surveys to update the morphological model of a limestone and gneiss deposit of a mining company near the city of Taubaté, Brazil. The research began with a test to verify the accuracy of the geophysical survey method and it was conducted in the same area as a previous drilling campaign with the aim of confirming the possibility of using Vertical Electrical Sounding (VES) and induced polarization (IP) methods, in order to obtain the required information for the deposit morphological modeling. As a result, the application of geophysical methods in the study area reduced up to 75% the data collection time and presented similar accuracy levels as conventional exploration methods used for the same research objectives.

Resumen Este artículo presenta los resultados de la aplicación de estudios geofísicos usados para la actualización del modelo morfológico de un depósito de caliza y gneis perteneciente a una compañía minera cerca de la ciudad de Taubaté, estado de Sao Paulo, Brasil. La investigación comenzó con un test de verificación de exactitud del método geofísico de estudio, el cual fue realizado con una campaña de perforación realizada previamente en la misma área de estudio, con el objetivo de confirmar la posibilidad de utilizar los métodos de Sondeo Eléctrico Vertical (SEV) y de Polarización Inducida (IP) para obtener la información requerida para el modelado del depósito morfológico. Como resultado, la aplicación de los métodos geofísicos en el área de estudio redujo el tiempo de recolección hasta un 75% y presentaron un nivel de precisión similar al de los métodos de exploración convencionales utilizados para los mismos objetivos del estudio.

Abstract The Pau Branco mine supplies two blast furnaces with iron ore lumps, and currently, charcoal consumption for pig iron production accounts for 47% of the blast furnaces' operational cost. A geometallurgical model is presented to support an economic study considering reserve volumes, product quality, and operational costs based on the metallurgical performance of different iron ore typologies. Sample analysis provides values required in the model. From the model, an alternative production plan is presented with a positive impact of USD 25.6M over the current net present value of the mining/mill system.

Abstract This work adds the Activity-Based Costing Approach in mining operations with a product mix. After analyzing and collecting data from an aggregate mine located in Brazil, a cost model was built, and from that, a cost management and analysis methodology of a mine in operation is created. This work has the innovation advantages of using ABC as a tool for planning the operation of the mine, identifying the more profitable products. At the end, it is concluded that the creation of a cost model to be used in the operation of mining is a rewarding investment as it shows the profitable and unprofitable products.

Abstract This paper shows the work conducted at the Experimental Mine of the Research Center of Responsible Mining of the University of São Paulo, taking into account the theoretical issues presented in the first part of the article. The research was performed without changing the production cycle and without resorting to investments in new types of equipment: it has attempted to increase the productivity of the quarry, by lowering production costs and improving the quality of the product. Some Key Performance Indicators (KPIs) were established to monitor the results. A new blast design method, a more appropriate initiation sequence and some simple, inexpensive and effective solutions were identified and applied. The results show that the proper selection of delay timing can be of significant benefit to downstream processes as well as enhanced fragmentation itself.

Drilling and blasting are fundamental operations in the mining cycle and consti tute an important component of the mining costs. Rock fragmentation can in principle be managed by means of two options: by increasing or reducing the specific consumption of explosives, or by modifying the drilling pattern. The choice of one or other type of control depends on the relationship between the unit costs of drilling and explosives, and on technical restrictions or regulations imposed by different reasons. It is then necessary to identify the link between the blast design and some factors affecting the downstream processing of the product. This paper analyzes the theoretical basis aimed at evaluating the main parameters involved when organizing a production blast in open pit quarries. In particular, a method developed through the analysis of the results in a large number of limestone open pit quarries in Italy is described and commented. The first experimental results in Brazil have been obtained by applying this method at the Experimental Mine of the Research Center of Responsible Mining of the University of São Paulo. Experimental methods and results will be analyzed and discussed in the second part of this paper.

Esse trabalho tem seu foco no problema de sequenciamento e programação da lavra em mina a céu aberto com a alocação de equipamentos de carregamento, considerando um período de médio prazo. Nesse estudo, considera-se a existência de uma frota heterogênea de equipamentos de carga e de dois tipos de materiais lavráveis, sendo minério ou estéril. Para a lavra de minério, são contemplados requisitos de qualidade da mistura, um britador, capacidade da usina de beneficiamento e uma pilha de estoque, denominada pilha de ROM. Nesse contexto, apresenta-se um modelo matemático em programação linear inteira mista, apoiado por um algoritmo responsável por mover o horizonte de tempo, a cada execução do modelo, com intuito de gerar ordens de lavra resolvidas com otimalidade. Juntas, essas ordens descreverão o plano de lavra dos equipamentos de carga.

This paper focuses on the sequencing and scheduling problem of open pit mining, with the allocation of loading equipment considering a medium-term horizon. This study considers the existence of a heterogeneous loading equipment fleet and two types of mineable material, namely ore or waste rock. For the mining of ore, the following requirements are taken under consideration: the mixture quality, a crusher, the processing plant capacity and a stockpile, called ROM stockpile. In this context, we present a mathematical model in mixed integer linear programming, supported by an algorithm that is responsible for moving the time horizon at each model run, aiming to generate mining orders resolved with optimality. Together, these orders describe the loading equipment mining plan.

Atualmente no mundo, devido ao elevado preço do ouro, milhares de pequenas minas artesanais operam sem a capacidade financeira ou técnica para atualizar seus métodos de produção, muitas vezes utilizando equipamentos e métodos de lavra que foram abandonados há décadas na indústria mineral convencional. Esse artigo ilustra, com um exemplo prático, que é possível atingir os modernos requisitos de qualidade, segurança e produtividade, mesmo operando com equipamentos de lavra que possuem basicamente as mesmas características dos utilizados na década de 1950. A operação envolveu a escavação de um túnel de 6 metros e o desmonte de mais de 25 seções em rocha e concreto, em uma mina de ouro subterrânea. O artigo descreve como os principais problemas operacionais foram superados: a concepção de um padrão de perfuração eficaz que foi facilmente alcançável com o limitado equipamento local, a previsão do comportamento e a gestão do local explosivo com base em nitrato e a interação com as equipes de perfuração, a fim de determinar um ponto de acordo entre seus métodos de trabalho tradicionais e a visão científica do engenheiro. No final do artigo, são propostas algumas diretrizes gerais para a gestão de situações semelhantes, a fim de serem melhoradas a eficiência, a produtividade e a segurança das operações de perfuração e desmonte em minas subterrâneas de pequena escala.

In the world today, due to the current high price of gold, thousands of artisanal small-scale mines operate without the financial or technical capacity to upgrade their production methods, often using equipment and working methods that were forsaken decades ago in the conventional mining industry. This article illustrates, with a practical example, that it is possible to achieve the modern requirements of quality, safety and productivity, while operating with mining equipment that basically possesses the same characteristics as that employed in the 1950s. The operation involved the excavation of a 6 meter long tunnel and over 25 stoping sections in both rock and concrete by drilling and blasting in an underground gold mine. The article describes how the main operational problems were overcome. An effective drilling pattern was designed in order to be easily achievable with the limited local equipment. The behavior of the local nitrate explosive was effectively predicted and managed. The interaction with the drilling teams was managed in order to determine a meeting point between their traditional working methods and the scientific view of the engineer. At the end of the article some general guidelines are proposed for the management of similar situations, in order to improve the efficiency, productivity and safety of drill and blast operations in small-scale mines.