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By Freddy Salazar, Segundo Velasquez, Robert Montes

Compañía Minera Coimolache, ubicada en la región Cajamarca, es una empresa a tajo abierto que produce oro y plata. El mineral es lixiviado con solución de cianuro de sodio, proceso del que se obtiene una solución pregnant que posteriormente se trata en la planta de Merrill Crowe y ADR según su ley. Sin embargo, debido a las precipitaciones, el agua de lluvia incrementa el inventario de solución con cianuro en el proceso, por lo que se hace necesario su tratamiento en la planta de detoxificación de cianuro. Ante este panorama, se buscó la oportunidad de reemplazo del cloruro férrico, identificando el agua ácida proveniente del depósito de material estéril como principal candidato para este reemplazo

Sep 29, 2023

By B. P. Watson, D. P. Roberts, R. A. Lamos

The Upper Group 2 (UG2) chromitite reef is a shallow-dipping stratiform tabular orebody in the South African Bushveld Complex, which strikes for hundreds of kilometres. Mining is extensive, with depths ranging from close-to-surface to 2 500 m. Pillars are widely used to support the open stopes and bords. Little work has been done in the past to determine the strength of pillars on the UG2 Reef and design was done using formulae developed for other hard-rock mines. This has led to oversized pillars with consequent sterilization of ore. In this paper we describe a back-analysis of stable and failed UG2 pillars on the Bushveld platinum mines, and provides a strength formula for UG2 pillars. The formula may be used cautiously on all Bushveld platinum mines with similar geotechnical, geometrical, and geomechanical conditions to the pillars in the database.

Aug 1, 2021

By H. Möller, L. Mashigo, C. Gassmann

Wire-arc additive manufacturing (WAAM) is a directed-energy deposition technology that uses arc welding procedures to produce computer-aided designed parts, such as three-dimensional printed metal components. A challenge of additive manufacturing is the anisotropy. Interstitial elements play a significant role in the mechanical properties of Ti6Al4V of different grades. In this research, the mechanical properties of Grade 5 and Grade 23 Ti6Al4V were compared for this application. Samples were extracted from WAAM-produced Ti6Al4V walls in different directions (horizontal and vertical) and at different positions (top and bottom). The samples were subjected to optical microscopy and tensile and hardness tests. Grade 5 Ti6Al4V samples were found to have greater strength, greater hardness, and lower ductility, owing to the higher content of interstitial elements compared with Grade 23. The bottom samples had higher strength than the top samples, which is attributed to thermal cycling during manufacturing, resulting in different microstructures.

Jul 1, 2021

By L. Uotinen, M. Rinne, R. Mishra

Underground mining gives rise to geotechnical hazards. A formal geotechnical risk assessment can help to forecast and mitigate these hazards. Frequentist probability methods can be used when the hazard does not have many variables and a lot of data is available. However, often there is not enough data for probability distributions, such as in the case of new projects. The risk assessment is often subjective and qualitative, based on expert judgement. The purpose of this research is to present the use of Bayesian networks (BNs) as an alternative to existing risk assessment methods in underground mines by combining expert knowledge with data as it becomes available. Roof fall frequency forecasting using parameter learning is demonstrated with 1141 sets of roof fall data across 12 coal mines in the USA. The prediction is nearly identical for individual mines, but when multiple mines are evaluated it is difficult to find a single best fit distribution for annual roof fall frequency. The BN approach with TNormal distribution was twice as likely to fit the observed data compared to the Poisson distribution assumed in the past. A hybrid approach using BN combining multiple probability distribution curves from historical data to predict annual roof fall is proposed. The BN models can account for variability for multiple parameters without increasing the complexity of the calculation. BNs can work with varying amounts of data, which makes them a good tool for real-time risk assessment in mines.

Jun 1, 2021

By Dinner Paredes

El presente trabajo técnico, denominado “Impulsando la competitividad minera en el Perú: La economía circular y los incentivos tributarios como elementos claves para el desarrollo de una minería sostenible”, tiene como propósito primordial analizar y resaltar la importancia que tienen los principios de la economía circular y los incentivos tributarios para promover un sector minero competitivo y sostenible en el Perú.

Sep 29, 2023

By Ma Fangyuan, Li Min, Xu Bing, Xian Yushuai, Zhao Tonglin

The study explored a new combination amine collector (XK-28) that can obtain better flotation index and defoaming rate for magnetic iron ore. A pure quartz mineral test indicates that dodecylamine, XK-I, or XK-II has good collection effect on quartz and their best flotation pH is in the range of 6–7. The experimental results of a combination collector (XK-I:XK-II = 2:8.) show that the separation effect for quartz and magnetite is better than that of a single collector. The single factor for actual mineral test shows that when the combined reagent is used as the collector, the best conditions are pH = 7, 90 g/t dosage, and XK-I:XK-II = 2:8, which is consistant with the pure mineral test. The difference for dodecylamine as a collector is that the optimal dodecylamine dosage is 60 g/t. Under the best conditions of actual ore test, dodecylamine and XK-28 are respectively used as the collector to compare the flotation indexes. Study results indicate the magnetite grade using XK-28 as the collector is higher by 3.02% than that of using dodecylamine, recovery is increased by 1.92% over that of using dodecylamine. Based on the measurement results of zeta potential, uses of XK-28 can slightly increase the zeta potential difference of quartz and magnetite to enhance the flotation effect. The mechanism of action between the XK-28 collector and the actual ore from the Gongchangling plant is physical adsorption, and this adsorption also has hydrogen bond formation. Contact angle results shows that XK-28 improves the hydrophobicity of quartz better than dodecylamine. Compared with dodecylamine, XK-28 is more sparsely arranged on the surface of the foam. The foam produced by the XK-28 collector has better air permeability and it is more likely to merge and disappear with bubbles.

Jul 21, 2021

By Karoly (Charles) Kocsis, Kyle A. Scalise

Understanding the climatic conditions in underground mines is necessary for efficient ventilation design, cost savings, and to ensure the health and safety of mine workers. Large volumes of ventilation and climatic data including air volume, barometric pressure, dry bulb temperature, and relative humidity were collected at active underground precious metal mines in Nevada, which allows for the determination of wet bulb temperature and other key parameters. Through the utilization of neural networks, the wet bulb temperature at the bottom of the intake shafts is predicted, while taking into account the “thermal flywheel effect” (TFE). Wet bulb temperature is one of the most important climatic parameters to model and understand because it significantly affects the work conditions and the cooling capacity of the ventilating air. The accurate prediction of the dry bulb and the wet bulb temperatures at the bottom of intake shafts is critical when assessing the climatic conditions in future underground mines and deciding onwhether a cooling system is needed to assure adequate working conditions throughout themine. By utilizing accurate predictions of wet bulb temperatures and other climatic parameters, mine personnel will be safer as reported by Bluhm et al. (2003), and a more accurate ventilation design can be achieved resulting in major cost savings for underground mines.

Mar 3, 2021

By Julián M. Ortiz, Antoine Caté, Oy Leuangthong, Ilkay S. Cevik

Mineral resource classification relies on the expert assessment of a qualified person (QP) to determine which blocks of a 3D mineral resource model are classified as measured, indicated, or inferred. The decision is often based on a combination of quantitative parameters related to the estimation process and qualitative decisions based on previous experience or preconceptions not captured in the numerical model. As such, the procedure is subject to inconsistency, that is, blocks with similar qualities may end up in different categories, mainly due to the subjective nature of the approach. In this paper, we present a methodology to assist the qualified person in this task by clustering blocks with similar parameters and then classifying them into categories in a consistent and automatic manner that only requires the specification of a few hyper-parameters. The result is a consistent classification into resource categories comparable to the result of a classification done by a qualified person but fully consistent and generated in a short time frame. The procedure begins with repeatedly sub-sampling the block model to determine a distance matrix using an unsupervised random forest approach and then clustering the blocks using the associated distance matrix. Then, all the blocks in the model are classified using a supervised random forest approach, which gives a probability of belonging to each class. The initial class can be determined from the class probabilities. Support vector classification with a radial basis function kernel is utilized to smooth the boundaries between classes and define the final classification. An approach to tune the hyper-parameters of smoothing is provided. The methodology is demonstrated with two examples from two gold deposits. Results are comparable to the classification done by the project qualified person using conventional methods.

Aug 17, 2021

By F. N. Siddiquie, Mohd Shaif, Rajiullah Khan, Juned Alam

Manganese ore bodies of Banswara Mn belt were classified into stratiform and stratabound types, based on their mode of occurrence, distribution, and their chemical characters. These ore bodies generally composed of braunite, pyrolusite, cryptomelane/ psilomelane, wad, etc. The stratiform-type Mn ore bodies are conformable with the associated host rocks (Mn phyllite, etc.) and occurred in the form of layers, bands, etc., which are variable in their shape and size. These ore bodies are also strongly folded with the enclosing host rocks. The others, which are stratabound-type Mn ore bodies, also showed an intimate association with the associated host rocks. These types of ore bodies occurred in thin layers, pockets, lenses, stringers, etc. The classified ore bodies are confined with Kalinjara formation of Aravalli Supergroup of Paleoproterozoic age. The ore bodies are structurally controlled and well associated with phyllite, schist, limestone, quartzite, etc. The stratiform-type ore bodies constitute a marginal to low Mn grade and are also characterized by lower Mn content (26.19–39.24%) along with the Mn/Fe ratio of 7.16–12.23, while the stratabound-type Mn ore bodies are rich in Mn (35.92–49.64%) along with the higher Mn/Fe ratio of 14.15–23.97. However, the poor Mn grade along with high siliceous impurities of Banswara Mn deposits is subjected to them for intermittent mining activities in the past and, consequently, did not attract the scientific and industrial community for the evaluation of these resources. Therefore, the authors attempted this study in a scientific and systematic manner (mode of occurrence/distribution and possible methods for evaluation/exploration) to evaluate the potential of existed and newer Mn deposit resources in the Banswara Mn belt. The whole findings would be very much helpful for exploration/ mining geologist along with other concerned, to completely evaluate these Mn deposits in the future.

Aug 16, 2021

By Rushikesh Battulwar, Javad Sattarvand, Joseph Seamons, Masoud Zare

In the last decade, new developments took place in the area of indoor positioning (or localization). Since the Global Navigation Satellite System (GNSS) cannot be used in underground mines, other technologies are needed for localization. Positioning and communication options today primarily include Wi-Fi, Bluetooth Low Energy (BLE), Ultra-Wideband (UWB), Radio Frequency Identification Device (RFID), etc. Smartphones and tablets currently have an array of sensors and radios, which can provide valuable information to allow indoor localization via various methods. Where mineworkers could keep smartphones with them, they can be highly effective at enabling localization and navigation. Recent applications of these technologies in underground mines have been thoroughly reviewed and examined for the likelihood of their utility for accurate localization where no other means exist. Some critical challenges and gaps that need to be addressed in future research have been identified.

Sep 5, 2021

By P. Samanta, Mohammed N. Azad, Gustad F. Taraporewalla, A. K. Mukherjee, Abhay S. Patra, D. Sachinraj

Beneficiation of coal is a water intensive process, and the water is recovered in downstream operations in the high rate thickener (HRT) and vacuum belt filtration (VBF). Clean coal particles entering the HRT have an inherent tendency to enter the overflow because they are extremely fine and hydrophobic. Hence, flocculants (polymers) are used to floc the ultrafine particles so that they settle and enter the underflow. Ultrafine coal particles (−37 μ), which are highly hydrophobic, if present in the stream, will not be efficiently captured by using flocculants alone. This is observed in the normal plant operation at one of the beneficiation plants in the Jharia region, Jharkhand, India. Approximately 6–7% of the feed to the HRT enters the over flow (supernatant water). Hence, this amount of clean coal particles is not recovered and account for production losses. A comprehensive settling and dewatering test work was conducted with clean coal slurry using several commercially available reagents. Studies were also done on different combinations of reagents, including coagulants and surfactants along with flocculants, to improve the settling behavior of the coal particles. The reagents were assessed based on their performance with respect to settling rates, overflow water clarity, and compaction of the underflow solids. Emphasis was given to the ability of the reagents in compacting thickener underflow to higher densities so that maximum water could be recovered from the thickener. Pretreatment of highly hydrophobic coal slurry with a combination of coagulant and surfactant followed by flocculation showed very good settling characteristics with clear overflow.

Sep 30, 2021

By Onuralp Yücel, Kağan Benzeşik, Ömür Can Odabaş, Selçuk Kan

Extraction and processing constitute an important area in the metallurgy of molybdenum. Molybdenum trioxide (MoO3) production is one of the most important stages in molybdenum production. In this study, the effects of different furnace types on MoO3 production were investigated by using molybdenum concentrate as a raw material obtained during the enrichment of copper ores. Preliminary experiments have been made using a chamber type furnace, and a transition to a pilot-scale has been carried out with rotary kiln experiments. The effects of a different time and atmospheric conditions on MoO3 roasting kinetics were investigated by experimental studies conducted in the temperature range of 500–650°C. It was determined that the optimum temperature and time for sulfur (S) removal was 625°C and 180 min in the studies carried out in the rotary kiln, and it was determined that 0.61%S content was reached with an average removal efficiency of 98%. The activation energy in these sets was calculated as 89.519 kJ/mol.

May 3, 2021

By J. Zhang, A. J. S. Spearing, L. Ma

Ore deposits are becoming more complex to mine as a result of the exhaustion of surface and other easily mined deposits. There is also increasing socio-political pressure to design more environmentally sound, sustainable, and safe mining practices. Wang and Ma designed a mining method for coal, similar to a modified drift and fill using a continuous miner to take sequential cuts (rooms) that are subsequently backfilled. The authors have modified the concept to make it more autonomous, safer, and less costly using highwall coal mining techniques, modified and adapted for underground applications. The method is more flexible than longwall mining and the percentage extraction would seem to be in the same range. In addition because of the backfilling, surface subsidence would not be a major issue and could be more effectively managed.

Feb 2, 2021

By S. Lohmeier, D. Gallhofer, B. G. Lottermoser, T. Schirmer

At a time of resource consumption, it is important to study the chemical composition of mining and metallurgical wastes to prevent the dissipative loss of metals and metalloids from the mining value chain. In particular, the recovery of critical elements from wastes is an option to increase the resources of such materials that are economically significant and have an overall supply risk. In this paper we report on the chemical composition, in particular the critical element content, of granulated slag originating from historical smelting activities in the Tsumeb area, Namibia. Laboratory-based inductively coupled plasma–mass spectrometry (ICP-MS) and X-ray fluorescence (XRF) analyses as well as portable X-ray fluorescence (pXRF) demonstrate that the slags are on average enriched in base metals (Cu 0.7 wt%, Pb 2.7 wt%, Zn 4.7 wt%), trace metals and metalloids (Cd approx. 50 mg/kg, Mo approx. 910 mg/kg) as well as critical elements (As approx. 6300 mg/kg, Bi approx. 3 mg/kg, Co approx. 200 mg/kg, Ga approx. 100 mg/kg, In approx. 9 mg/kg, Sb approx. 470 mg/kg). While metals and metalloids such as As, Mo and Pb can be determined reliably using pXRF instruments, the technique has inherent limitations in evaluating the contents of certain critical elements (Ga, Sb). However, there are positive correlations between the As, Mo, and Pb contents determined by pXRF and the Ga and Sb contents obtained through ICP-MS and XRF. Thus, quantitative pXRF analysis for As, Mo, and Pb allows calculation of Ga and Sb abundances in the slags. This work demonstrates that pXRF analysers are a valuable tool to screen smelting slags for their chemical composition and to predict the likely contents of critical elements.

Mar 1, 2021

By I. J. Geldenhuys

South Africa’s mining and metals industries have an illustrious history dating back to the Late Iron Age. We live in a complex and data-intensive world that has already fundamentally changed how we work and live. The outbreak of the global COVID-19 pandemic in 2020 resulted in immeasurable suffering worldwide, but the crisis also accelerated many technological developments and altered the way we think about, and experience, technology and work. Problem-solving requires new and rapidly changing skills to manage the data tsunami. Whether at the rock face or on the processing plant, the fundamentals have not changed, although how we interact with minerals and their properties has changed dramatically. Sustainable processing and design are non-negotiable if we genuinely want to achieve the aim of the cradle-to-cradle principle. As we venture forth, what can scientists, engineers, technologists, and mathematicians learn from history? History is data presented in a context; sometimes, the context is also important. We exist in an age of data, with most of the world’s data created in only the past two years. History can enhance our understanding of the present and enhance our future outcomes. Lessons from history can help provide insights into making ethical and sustainable choices related to technology or engineering in the mining and metallurgical industry. Shifting the perspective of mining and metallurgy professionals from a narrow focus on complex technical solutions towards a broader context for problem-solving and designs that includes the entire ecosystem is crucial. In other words, using or reflecting on historical process development is, at its core, systems thinking.

Sep 1, 2021

By Alberto Guizado

A la fecha ciertos consumidores de energía eléctrica, entre los que se encuentran las empresas mineras, pagan mensualmente, además del IGV e Impuesto de Promoción Municipal, otras 3 obligaciones, considerados, por no pocos, como subsidios cruzados y en ciertos casos como impuestos, cuyos egresos son directamente proporcional al consumo de la energía eléctrica (a mayor uso del suministro, corresponde aumento en los pagos).

Sep 29, 2023

By Edgardo Rabanal, Mario Adrianzén

El presente trabajo nos permitirá demostrar las bondades del potencial que tiene el enfoque de Newmont para la gestión de riesgos integral que es el Sistema de Gestión de Riesgos (RMS Risk Management Sistem) uno de los principales componentes es la Gestión de Riesgos de Fatalidad (FRM, por sus siglas en inglés de Fatal Risk Management) que es una herramienta primordial de gestión para evitar fatalidades. En los proyectos de Newmont Yanacocha (Proyecto Yanacocha Sulfuros YSP y Proyecto de Tratamiento de Aguas WTP2) se utiliza el FRM para brindar asesoramiento, acompañamiento y empoderamiento en la salud y seguridad de las empresas locales y sus colaboradores.

Sep 29, 2023

By Daniel Lovera, Freddy Sojo, Edwin Manrique

El agua de mina es un problema constante en las empresas minero metalúrgicas debido a su alta acidez y contenido de iones disueltos. Esto ocasiona constantes desembolsos para su tratamiento antes de ser desechado. Mientras los concentrados de cobre por su alto contenido de calcopirita requieren del proceso de tostación para recuperar el cobre valioso generando emisión de gases contaminantes. En esta investigación se emplea 4 soluciones de lixiviación con el agua de mina como componente principal y diferentes concentraciones de cloruro de sodio (NaCl), nitrato de sodio (NaNO3) e hipoclorito de calcio (Ca(ClO)2). El concentrado empleado contiene principalmente calcopirita.

Sep 29, 2023

By Paul Ruíz

Con el objetivo de aumentar la utilización de la flota de acarreo, la Compañía Minera Antamina implementó el proyecto llamado "Relevo en Caliente" en el año 2022. En el marco de este proyecto, se incorporaron 196 aprendices procedentes de las comunidades cercanas, de los cuales el 41% fueron mujeres. El propósito de esta iniciativa era formarlos como operadores de camión minero

Sep 29, 2023

By Hilario Gorvenia, Eduardo Ku

Los controles predictivos del tipo de mineral, cambios de reología, etc., que ingresará a la Planta, anticipará al área de Operaciones y al área de Gestión de Relaves para realizar las acciones pertinentes en la disposición de relaves para prevenir imprevistos en la producción de la Planta. El presente trabajo propone una metodología de planificación desde la Mina para optimizar el tiempo de vida útil de los depósitos de relaves y maximizar la recuperación de agua desde los relaves.

Sep 29, 2023