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Six different particle size distribution (Gates–Gaudin–Schuhmann (GGS), Rosin–Rammler (RR), Lognormal, Normal, Gamma, and Swebrec) models were compared under different metallurgical coke grinding conditions (ball size and grinding time). Adjusted R2, Akaike information criterion (AIC), and the root mean of square error (RMSE) were employed as comparison criteria. Swebrec and RR presented superior comparison criteria with the higher goodness-of-fit and the lower AIC and RMSE, containing the minimum variance values among data. The worst model fitting was GGS, with the poorest comparison criteria and a wider results variation. The undulation Swebrec parameter was ball size and grinding time-dependent, considering greater b values (b > 3) at longer grinding times. The RR α parameter does not exhibit a defined tendency related to grinding conditions, while the k parameter presents smaller values at longer grinding times. Both models depend on metallurgical coke grinding conditions and are hence an indication of the grinding behaviour. Finally, oversize and ultrafine particles are found with ball sizes of 4.0 cm according to grinding time. The ball size of 2.54 cm shows slight changes in particle median diameter over time, while 3.0 cm ball size requires more grinding time to reduce metallurgical coke particles.
Laura Colorado-Arango; Juan M. Menéndez-Aguado; Adriana Osorio-Correa. Particle Size Distribution Models for Metallurgical Coke Grinding Products. Metals 2021, 11, 1288 .
AMA StyleLaura Colorado-Arango, Juan M. Menéndez-Aguado, Adriana Osorio-Correa. Particle Size Distribution Models for Metallurgical Coke Grinding Products. Metals. 2021; 11 (8):1288.
Chicago/Turabian StyleLaura Colorado-Arango; Juan M. Menéndez-Aguado; Adriana Osorio-Correa. 2021. "Particle Size Distribution Models for Metallurgical Coke Grinding Products." Metals 11, no. 8: 1288.
Over the years, alternative procedures to the Bond grindability test have been proposed aiming to avoid the need for the standard mill or to reduce and simplify the grinding procedure. Some of them use the standard mill, while others are based on a non-standard mill or computation techniques. Therefore, papers targeting to propose a better alternative claim to improve validity, to reduce test duration, or to propose simpler and faster alternative methods for determining the Bond work index (wi). In this review paper, a compilation and critical analysis of selected proposals is performed, concluding that some of the short procedures could be useful for control purposes, while the simulation-based procedures could be interesting within a process digitalisation strategy.
Vladimir Nikolić; Gloria García; Alfredo Coello-Velázquez; Juan Menéndez-Aguado; Milan Trumić; Maja Trumić. A Review of Alternative Procedures to the Bond Ball Mill Standard Grindability Test. Metals 2021, 11, 1114 .
AMA StyleVladimir Nikolić, Gloria García, Alfredo Coello-Velázquez, Juan Menéndez-Aguado, Milan Trumić, Maja Trumić. A Review of Alternative Procedures to the Bond Ball Mill Standard Grindability Test. Metals. 2021; 11 (7):1114.
Chicago/Turabian StyleVladimir Nikolić; Gloria García; Alfredo Coello-Velázquez; Juan Menéndez-Aguado; Milan Trumić; Maja Trumić. 2021. "A Review of Alternative Procedures to the Bond Ball Mill Standard Grindability Test." Metals 11, no. 7: 1114.
As a continuation of a previous research work carried out to estimate the Bond work index (wi) by using a simulator based on the cumulative kinetic model (CKM), a deeper analysis was carried out to determine the link between the kinetic and energy parameters in the case of metalliferous and non-metallic ore samples. The results evidenced a relationship between the CKM kinetic parameter k and the grindability index gbp; and also with the wi, obtained following the standard procedure. An excellent correlation was obtained in both cases, posing the definition of alternative work index estimation tests with the advantages of more straightforward and quicker laboratory procedures.
Victor Ciribeni; Juan Menéndez-Aguado; Regina Bertero; Andrea Tello; Enzo Avellá; Matías Paez; Alfredo Coello-Velázquez. Unveiling the Link between the Third Law of Comminution and the Grinding Kinetics Behaviour of Several Ores. Metals 2021, 11, 1079 .
AMA StyleVictor Ciribeni, Juan Menéndez-Aguado, Regina Bertero, Andrea Tello, Enzo Avellá, Matías Paez, Alfredo Coello-Velázquez. Unveiling the Link between the Third Law of Comminution and the Grinding Kinetics Behaviour of Several Ores. Metals. 2021; 11 (7):1079.
Chicago/Turabian StyleVictor Ciribeni; Juan Menéndez-Aguado; Regina Bertero; Andrea Tello; Enzo Avellá; Matías Paez; Alfredo Coello-Velázquez. 2021. "Unveiling the Link between the Third Law of Comminution and the Grinding Kinetics Behaviour of Several Ores." Metals 11, no. 7: 1079.
It is a well-known fact that the value of the Bond work index (wi) for a given ore varies along with the grinding size. In this study, a variability bysis is carried out with the Bond standard grindability tests on different critical metal ores (W, Ta), ranging from coarse grinding (rod mills) to fine grinding (ball mills). The relationship between wi and grinding size did not show a clear correlation, while the grindability index (gpr) and the grinding size showed a robust correlation, fitting in all cases to a quadratic curve with a very high regression coefficient. This result suggests that, when performing correlation studies among ore grindability and rock mechanics parameters, it is advised to use the grindability index instead of the Bond work index.
Gloria García; Josep Oliva; Eduard Guasch; Hernán Anticoi; Alfredo Coello-Velázquez; Juan Menéndez-Aguado. Variability Study of Bond Work Index and Grindability Index on Various Critical Metal Ores. Metals 2021, 11, 970 .
AMA StyleGloria García, Josep Oliva, Eduard Guasch, Hernán Anticoi, Alfredo Coello-Velázquez, Juan Menéndez-Aguado. Variability Study of Bond Work Index and Grindability Index on Various Critical Metal Ores. Metals. 2021; 11 (6):970.
Chicago/Turabian StyleGloria García; Josep Oliva; Eduard Guasch; Hernán Anticoi; Alfredo Coello-Velázquez; Juan Menéndez-Aguado. 2021. "Variability Study of Bond Work Index and Grindability Index on Various Critical Metal Ores." Metals 11, no. 6: 970.
An evaluation of Relo grinding media (RGM, Reuleaux tetrahedron-shaped bodies) performance versus standard grinding media (balls) was made through a series of grinding tests, including a slight modification of the standard Bond test procedure. Standard Bond tests showed a reduction in the Bond ball mill work index (wi ) of the mineral sample used in this study when using Relo grinding media. The modified Bond test procedure is based on using the standard Bond ball work index test but changing the circulating loads (350%, 250%, 150%, 100%). The comparative tests with RGM were carried out at the same number of revolutions as the grinding tests with balls at respective circulating load. The RGM charge yielded a 14% higher net undersize product than balls, which hints at improving energy efficiency and the potential for significant mining industry benefits.
Nikolay Kolev; Petar Bodurov; Vassil Genchev; Ben Simpson; Manuel Melero; Juan Menéndez-Aguado. A Comparative Study of Energy Efficiency in Tumbling Mills with the Use of Relo Grinding Media. Metals 2021, 11, 735 .
AMA StyleNikolay Kolev, Petar Bodurov, Vassil Genchev, Ben Simpson, Manuel Melero, Juan Menéndez-Aguado. A Comparative Study of Energy Efficiency in Tumbling Mills with the Use of Relo Grinding Media. Metals. 2021; 11 (5):735.
Chicago/Turabian StyleNikolay Kolev; Petar Bodurov; Vassil Genchev; Ben Simpson; Manuel Melero; Juan Menéndez-Aguado. 2021. "A Comparative Study of Energy Efficiency in Tumbling Mills with the Use of Relo Grinding Media." Metals 11, no. 5: 735.
Ta and Nb are considered critical raw materials due to their properties and potential applications in a wide range of sectors. This study deals with Sn-Ta-Nb minerals from the Penouta mine (Orense, Spain), the only active mine in Europe producing tantalum minerals. These minerals are obtained from mining waste accumulated during old mining operations in tailing ponds. The industrial processing flowsheet is based on successive gravimetric stages followed by low intensity magnetic separation to reduce ferromagnetic contaminants. A Sn-Ta-Nb concentrate, with grades between 35–45% Sn and 4–7% Ta2O5 and Nb2O5, is obtained in this stage with plant recoveries around 60–70%, respectively. A chemical-mineralogical characterization by size fractions, XRF and XRD was carried out to implement a size classification stage in the processing plant. The finest fractions, containing higher grades of well-liberated Sn, Ta, and Nb minerals were utilized as the feed for dry high intensity magnetic separation (DHIMS) multifactorial tests, while coarse fractions were regrinded to maximize performance. The favorable results obtained in these tests demonstrate that two products with commercial quality can be obtained: a cassiterite concentrate with grades between 70–78% SnO2 and a tantalite-columbite concentrate with grades ranging between 12 and 14% Ta2O5 and Nb2O5, while also increasing the overall recovery of the plant.
Jennire Nava; Teresa Llorens; Juan Menéndez-Aguado. Characterization, Classification, Dry High-Intensity Magnetic Separation (DHIMS), and Re-Grinding Techniques to Improve the Mineral Performance of a Sn-Ta-Nb Mineral Concentrate. Environmental Sciences Proceedings 2021, 6, 10 .
AMA StyleJennire Nava, Teresa Llorens, Juan Menéndez-Aguado. Characterization, Classification, Dry High-Intensity Magnetic Separation (DHIMS), and Re-Grinding Techniques to Improve the Mineral Performance of a Sn-Ta-Nb Mineral Concentrate. Environmental Sciences Proceedings. 2021; 6 (1):10.
Chicago/Turabian StyleJennire Nava; Teresa Llorens; Juan Menéndez-Aguado. 2021. "Characterization, Classification, Dry High-Intensity Magnetic Separation (DHIMS), and Re-Grinding Techniques to Improve the Mineral Performance of a Sn-Ta-Nb Mineral Concentrate." Environmental Sciences Proceedings 6, no. 1: 10.
This study analyzes various regulatory framework mechanisms applied to prevent, minimize, and mitigate environmental accidents and disasters, within the extractive mining industry, in seven Latin American countries. The selected countries offer an ample view of the mining industry specter since each one of them is at the different development stages, such as Chile, Bolivia, Mexico, and Brazil. Nevertheless, some of the countries have similar technical characteristics, as is the case of Peru, Colombia, and Ecuador. Controls and regulations employed in each of the countries reveal particularities that should be appreciated and understood. In conclusion, the existence of mining regulations has not diminished the occurrence of environmental accidents in those countries. However, the existing environmental controls allow authorities to quantify with substantial precision the degree of impact coming from Latin America’s mining industry. Furthermore, for more than a decade, mining industries have been subjected to several global initiatives to integrate elements of corporative social responsibility into their management systems—mainly in strong cooperation with different governmental formalization programs. The key focus is, cooperation among different scales (industry and small-scale and artisanal mining) which challenged, but also improved the capacities of environmental authorities and the effectiveness of different legal frameworks.
Alby Aguilar-Pesantes; Elizabeth Peña Carpio; Tomas Vitvar; Ronald Koepke; Juan Menéndez-Aguado. A Comparative Study of Mining Control in Latin America. Mining 2021, 1, 6 -18.
AMA StyleAlby Aguilar-Pesantes, Elizabeth Peña Carpio, Tomas Vitvar, Ronald Koepke, Juan Menéndez-Aguado. A Comparative Study of Mining Control in Latin America. Mining. 2021; 1 (1):6-18.
Chicago/Turabian StyleAlby Aguilar-Pesantes; Elizabeth Peña Carpio; Tomas Vitvar; Ronald Koepke; Juan Menéndez-Aguado. 2021. "A Comparative Study of Mining Control in Latin America." Mining 1, no. 1: 6-18.
The European Commission (EC) maintains the consideration of tungsten as a critical raw material for the European industry, being the comminution stage of tungsten-bearing minerals an essential step in the tungsten concentration process. Comminution operations involve approximately 3–4% of worldwide energy consumption; therefore, grinding optimization should be a priority. In this study, the grinding behavior of tungsten ore from Barruecopardo Mine (Salamanca, Spain) is analyzed. A protocol based on Austin´s methodology and PBM is developed in order to study the influence of operational and geometallurgical variables on grinding kinetics. In addition to the kinetic parameters, the breakage probability (Si) and breakage function (Bij) is determined. The selection function was formulated for the Barruecopardo Mine with respect to the mill speed.
Jennire V. Nava; Alfredo L. Coello-Velázquez; Juan M. Menéndez-Aguado. Grinding Kinetics Study of Tungsten Ore. Metals 2020, 11, 71 .
AMA StyleJennire V. Nava, Alfredo L. Coello-Velázquez, Juan M. Menéndez-Aguado. Grinding Kinetics Study of Tungsten Ore. Metals. 2020; 11 (1):71.
Chicago/Turabian StyleJennire V. Nava; Alfredo L. Coello-Velázquez; Juan M. Menéndez-Aguado. 2020. "Grinding Kinetics Study of Tungsten Ore." Metals 11, no. 1: 71.
The optimization of processing plants is one of the main concerns in the mining industry, since the comminution stage, a fundamental operation, accounts for up to 70% of total energy consumption. The aim of this study was to determine the effects that ball size and mill speed exert on the milling kinetics over a wide range of particle sizes. This was done through dry milling and batch grinding tests performed on two samples from the Penouta Sn–Ta–Nb mine (Galicia, Spain), and following Austin methodology. In addition, the relationships amongst Sn, Ta and Nb content, as metals of interest, the specific rate of breakage Si, the kinetic parameters, and the operational conditions were studied through X-Ray fluorescence (XRF) techniques. The results show that, overall, the specific rate of breakage Si decreases with decreasing feed particle size and increasing ball size for most of the tested conditions. A selection function, αT, was formulated on the basis of the ball size for both Penouta mine samples. Finally, it was found that there does exist a direct relationship amongst Sn, Ta and Nb content, as metals of interest, in the milling product, the specific rate of breakage Si and the operational–mineralogical variables of ball size, mill speed and feed particle size.
Jenniree V. Nava; Teresa Llorens; Juan María Menéndez-Aguado. Kinetics of Dry-Batch Grinding in a Laboratory-Scale Ball Mill of Sn–Ta–Nb Minerals from the Penouta Mine (Spain). Metals 2020, 10, 1687 .
AMA StyleJenniree V. Nava, Teresa Llorens, Juan María Menéndez-Aguado. Kinetics of Dry-Batch Grinding in a Laboratory-Scale Ball Mill of Sn–Ta–Nb Minerals from the Penouta Mine (Spain). Metals. 2020; 10 (12):1687.
Chicago/Turabian StyleJenniree V. Nava; Teresa Llorens; Juan María Menéndez-Aguado. 2020. "Kinetics of Dry-Batch Grinding in a Laboratory-Scale Ball Mill of Sn–Ta–Nb Minerals from the Penouta Mine (Spain)." Metals 10, no. 12: 1687.
Over the last decades, several reliable mathematical models have been developed for simulating ore comminution processes and determining the Work Index. Since Fred Chester Bond developed the Work Index standard procedure in 1961, numerous attempts have been made to find simpler, faster, and economically more advantageous alternative tests. In this paper, a Bond test simulation based on the cumulative kinetic model (CKM) has been checked on a spreadsheet. The research has been accomplished by conventionally determining the kinetic parameters for some Ag and Au ores and for three pure minerals and one rock that are common constituents of the gangue rock. Analysis of the results obtained allowed to develop a simplified procedure for calculating the kinetic parameters and their application to Work Index determination through simulation.
Victor Ciribeni; Regina Bertero; Andrea Tello; Matías Puerta; Enzo Avellá; Matías Paez; Juan María Menéndez Aguado. Application of the Cumulative Kinetic Model in the Comminution of Critical Metal Ores. Metals 2020, 10, 925 .
AMA StyleVictor Ciribeni, Regina Bertero, Andrea Tello, Matías Puerta, Enzo Avellá, Matías Paez, Juan María Menéndez Aguado. Application of the Cumulative Kinetic Model in the Comminution of Critical Metal Ores. Metals. 2020; 10 (7):925.
Chicago/Turabian StyleVictor Ciribeni; Regina Bertero; Andrea Tello; Matías Puerta; Enzo Avellá; Matías Paez; Juan María Menéndez Aguado. 2020. "Application of the Cumulative Kinetic Model in the Comminution of Critical Metal Ores." Metals 10, no. 7: 925.
The rheological behavior of mineral slurries shows the level of interaction or aggregation among particles, being a process control variable in processes such as slurry transportation, dehydration, and wet grinding systems. With the aim to analyze the effect of medium viscosity in wet grinding, a series of monosize grinding ball mill tests were performed to determine breakage parameters, according to the generally accepted kinetic approach of grinding processes. A rheological modifier (polyacrylamide, PAM) was used to modify solutions viscosity. A model was proposed by means of dimensional analysis (Buckingham’s Pi theorem) in order to determine the behavior of the specific breakage rate (Sj) for a ball grinding process in terms of the rheology of the system. In addition to this, a linear adjustment was established for the relationship between specific breakage rates with and without PAM addition, based on the reduced viscosity, μr. Furthermore, within a certain interval of viscosity, it was proved that an increment of viscosity can increase the specific breakage rate, and consequently the grinding degree.
Adriana M. Osorio; Moisés O. Bustamante; Gloria M. Restrepo; Manuel M. M. López; Juan M. Menéndez-Aguado. A Study of the Effect of Medium Viscosity on Breakage Parameters for Wet Grinding. Symmetry 2019, 11, 1202 .
AMA StyleAdriana M. Osorio, Moisés O. Bustamante, Gloria M. Restrepo, Manuel M. M. López, Juan M. Menéndez-Aguado. A Study of the Effect of Medium Viscosity on Breakage Parameters for Wet Grinding. Symmetry. 2019; 11 (10):1202.
Chicago/Turabian StyleAdriana M. Osorio; Moisés O. Bustamante; Gloria M. Restrepo; Manuel M. M. López; Juan M. Menéndez-Aguado. 2019. "A Study of the Effect of Medium Viscosity on Breakage Parameters for Wet Grinding." Symmetry 11, no. 10: 1202.
Mathematical models of particle size distribution (PSD) are necessary in the modelling and simulation of comminution circuits. In order to evaluate the application of the Swebrec PSD model (SWEF) in the grinding circuit at the Punta Gorda Ni-Co plant, a sampling campaign was carried out with variations in the operating parameters. Subsequently, the fitting of the data to the Gates-Gaudin-Schumann (GGS), Rosin-Rammler (RRS) and SWEF PSD functions was evaluated under statistical criteria. The fitting of the evaluated distribution models showed that these functions are characterized as being sufficiently accurate, as the estimation error does not exceed 3.0% in any of the cases. In the particular case of the Swebrec function, reproducibility for all the products is high. Furthermore, its estimation error does not exceed 2.7% in any of the cases, with a correlation coefficient of the ratio between experimental and simulated data greater than 0.99.
Alfredo Lázaro Coello-Velázquez; Víctor Quijano Arteaga; Juan M. Menéndez-Aguado; Francisco M. Pole; Luis Llorente. Use of the Swebrec Function to Model Particle Size Distribution in an Industrial-Scale Ni-Co Ore Grinding Circuit. Metals 2019, 9, 882 .
AMA StyleAlfredo Lázaro Coello-Velázquez, Víctor Quijano Arteaga, Juan M. Menéndez-Aguado, Francisco M. Pole, Luis Llorente. Use of the Swebrec Function to Model Particle Size Distribution in an Industrial-Scale Ni-Co Ore Grinding Circuit. Metals. 2019; 9 (8):882.
Chicago/Turabian StyleAlfredo Lázaro Coello-Velázquez; Víctor Quijano Arteaga; Juan M. Menéndez-Aguado; Francisco M. Pole; Luis Llorente. 2019. "Use of the Swebrec Function to Model Particle Size Distribution in an Industrial-Scale Ni-Co Ore Grinding Circuit." Metals 9, no. 8: 882.
The circular economy seeks to minimize the use of raw materials and waste generation. In this context, here we addressed the use of dunite mining tailings and subproducts to stabilize metal(oid)s in polluted soils. We first characterized the dunite mining tailings and subproducts, and a paradigmatic polluted soil in depth to determine their chemical and mineralogical properties. Experimental trials using Brassica juncea L. were performed to evaluate the impact of the two materials on vegetation growth, edaphic properties and pollutant stabilization yields. To this end, the plants were grown over 75 days in 1 kg pots containing the polluted soil amended with the dunite materials. Notably, both amendments caused a dramatic decrease in the available Zn and a moderate reduction in available Cu, Cd and Pb. In contrast, the concentration of available As was not modified. The cation exchange capacity (CEC) was improved by treatment with the amendments, allowing an increase in the biomass harvested. The immobilization mechanism achieved was probably due to an increase in pH and CEC. In conclusion, the dunite tailings and subproducts could be effective amendments for stabilizing polluted soil. This work paves the way for additional studies with distinct types of soils and conditions.
Diego Baragaño; Rubén Forján; Juan Maria Menendez-Aguado; Marcos Covián Martino; Pamela Díaz García; Javier Martínez Rubio; Juan José Álvarez Rueda; José Luis R. Gallego. Reuse of Dunite Mining Waste and Subproducts for the Stabilization of Metal(oid)s in Polluted Soils. Minerals 2019, 9, 481 .
AMA StyleDiego Baragaño, Rubén Forján, Juan Maria Menendez-Aguado, Marcos Covián Martino, Pamela Díaz García, Javier Martínez Rubio, Juan José Álvarez Rueda, José Luis R. Gallego. Reuse of Dunite Mining Waste and Subproducts for the Stabilization of Metal(oid)s in Polluted Soils. Minerals. 2019; 9 (8):481.
Chicago/Turabian StyleDiego Baragaño; Rubén Forján; Juan Maria Menendez-Aguado; Marcos Covián Martino; Pamela Díaz García; Javier Martínez Rubio; Juan José Álvarez Rueda; José Luis R. Gallego. 2019. "Reuse of Dunite Mining Waste and Subproducts for the Stabilization of Metal(oid)s in Polluted Soils." Minerals 9, no. 8: 481.
Mining activities in general, and quarrying processes in particular, generate huge amounts of tailings with a considerable presence of fine particles and with a variable composition of minerals, which could limit the direct application of those wastes. Under the paradigm of a circular economy, more effort has to be made to find adequate applications for those secondary raw materials. In this study, a process was proposed and tests were performed to valorise fine particle product as a raw material for the building and construction industry. Samples were taken from wastes in several aggregate production plants, being characterized and processed to remove the clayey components to obtain the cleanest quartz fraction. Then, different characterization and validation tests were carried out to analyse the application of these products as raw materials in the building and construction industry (cement and ceramics). Results showed that with no complex technologies, the tailings can be considered as a mineral raw material in different applications.
Menéndez-Aguado L.D.; Marina Sánchez M.; Rodríguez M.A.; Coello Velázquez A.L.; Menéndez-Aguado J.M.. Recycled Mineral Raw Materials from Quarry Waste Using Hydrocyclones. Materials 2019, 12, 2047 .
AMA StyleMenéndez-Aguado L.D., Marina Sánchez M., Rodríguez M.A., Coello Velázquez A.L., Menéndez-Aguado J.M.. Recycled Mineral Raw Materials from Quarry Waste Using Hydrocyclones. Materials. 2019; 12 (13):2047.
Chicago/Turabian StyleMenéndez-Aguado L.D.; Marina Sánchez M.; Rodríguez M.A.; Coello Velázquez A.L.; Menéndez-Aguado J.M.. 2019. "Recycled Mineral Raw Materials from Quarry Waste Using Hydrocyclones." Materials 12, no. 13: 2047.
The results of characterizing the alumina ball size distribution in two mills of a crushing and grinding plant are shown. The mills were unloaded and the ball charge was screened in order to establish the ball size distribution. For both mills, the balls retained during the unloading were compared to the balls retained at the beginning of the process, and additionally, they were compared to the results obtained by the Swebrec adjusted distribution model. In both cases, the experimental data have had a good fit with this model. This practice is important in order to establish the best ball charge at the beginning of the operation and the ball recharge in the steady state.
Lina María Chica Osorio; Ismael Eduardo Rivera; Marlon Rincón Fulla; Adriana Marcela Osorio; Moises Oswaldo Bustamante Rua; Juan María Menendez Aguado. Comparison of alumina ball size distribution in two white cement grinding units using Swebrec function. DYNA 2019, 86, 25 -29.
AMA StyleLina María Chica Osorio, Ismael Eduardo Rivera, Marlon Rincón Fulla, Adriana Marcela Osorio, Moises Oswaldo Bustamante Rua, Juan María Menendez Aguado. Comparison of alumina ball size distribution in two white cement grinding units using Swebrec function. DYNA. 2019; 86 (209):25-29.
Chicago/Turabian StyleLina María Chica Osorio; Ismael Eduardo Rivera; Marlon Rincón Fulla; Adriana Marcela Osorio; Moises Oswaldo Bustamante Rua; Juan María Menendez Aguado. 2019. "Comparison of alumina ball size distribution in two white cement grinding units using Swebrec function." DYNA 86, no. 209: 25-29.
The area of Ponce Enríquez, Southern Ecuador, is one of the most important artisanal and small scale gold mining (ASGM) areas in the country, where informal mining operations can be found using amalgamation technique, even though it has been prohibited since 2010. Considering the potential impact of these mining operations, the present research focused on heavy metal pollutants in subsurface sediments at 214 sampling locations from several detailed sampling campaigns in the rivers Fermín, Fermín Norte, Guanache, Villa, and Siete. Four parameters were calculated to evaluate the geochemical composition of the river sediment and heavy metal concentrations: The enrichment factor (EF), the geo-accumulation index (Igeo), the contamination factor (Cf) and the pollution load index (PLI). The analyzed elements were Cu, Pb, Zn, Ni, As, Cd, Sb, Sr, and Hg. Due to the lack of standards for pollution levels in sediments in Ecuador, Canadian guidelines were used as interim sediment quality guidelines (ISQG) in this research for comparison with the obtained results in subsurface sediments. The multi-index geochemical analysis indicated elevated heavy metal concentrations in all subsurface sediments in the studied river ecosystems.
Alby Aguilar Pesantes; Elizabeth Peña Carpio; Tomas Vitvar; Manuel María Mahamud López; Juan M. Menéndez-Aguado. A Multi-Index Analysis Approach to Heavy Metal Pollution Assessment in River Sediments in the Ponce Enríquez Area, Ecuador. Water 2019, 11, 590 .
AMA StyleAlby Aguilar Pesantes, Elizabeth Peña Carpio, Tomas Vitvar, Manuel María Mahamud López, Juan M. Menéndez-Aguado. A Multi-Index Analysis Approach to Heavy Metal Pollution Assessment in River Sediments in the Ponce Enríquez Area, Ecuador. Water. 2019; 11 (3):590.
Chicago/Turabian StyleAlby Aguilar Pesantes; Elizabeth Peña Carpio; Tomas Vitvar; Manuel María Mahamud López; Juan M. Menéndez-Aguado. 2019. "A Multi-Index Analysis Approach to Heavy Metal Pollution Assessment in River Sediments in the Ponce Enríquez Area, Ecuador." Water 11, no. 3: 590.
This study aims to show how fractal analysis applied to nitrogen and carbon dioxide adsorption isotherms helps to understand the textural changes during char activation. The materials under study were two series of activated carbons obtained by means of CO2 gasification of chars at 1123 K. The chars were obtained through carbonization at 1123 K of a high-volatile A bituminous coal that was previously oxidized in air at 543 and 473 K for periods of time from 0 up to 14 days. The fractal analysis of CO2 and N2 adsorption data corresponding to activated carbons is carried out by using the approaches of Neimark and Wang-Li. Fractal and other textural characteristics of the series of activated carbons are put side by side with those of the series of the corresponding chars. Pore network development through activation depends on the extent of the air preoxidation of the precursor coal as this step conditions the textural properties of the carbonized materials that also determine the behaviour during activation. Fractal and other textural characteristics indicate that coal preoxidation at 543 K leads to chars that are more stable during activation than those obtained from coals preoxidized at 473 K. The changes in fractal dimensions caused by gasification can be explained taking into account the classical textural properties, the effect of gasification and also the pore structure of the precursor char. The gasification process itself produces a decrease in fractal dimensions and the existence of non-accessible porosity in chars may contribute to an increase in fractal dimensions during activation. The prevalence of the smoothening effect of char gasification was found to be more important for the zones of the narrowest pores. Consequently, variation of fractal characteristics as a consequence of gasification depends on the technique employed for the analysis: CO2, N2 adsorption or mercury porosimetry.
Manuel María Mahamud; Juan Maria Menendez-Aguado; Alejandra Álvarez. Fractal analysis of CO2 and N2 adsorption data to assess textural changes during char gasification. Fuel Processing Technology 2019, 189, 15 -27.
AMA StyleManuel María Mahamud, Juan Maria Menendez-Aguado, Alejandra Álvarez. Fractal analysis of CO2 and N2 adsorption data to assess textural changes during char gasification. Fuel Processing Technology. 2019; 189 ():15-27.
Chicago/Turabian StyleManuel María Mahamud; Juan Maria Menendez-Aguado; Alejandra Álvarez. 2019. "Fractal analysis of CO2 and N2 adsorption data to assess textural changes during char gasification." Fuel Processing Technology 189, no. : 15-27.
The present study focuses on soil washing enhancement via soil pretreatment with nanoscale zero-valent iron (nZVI) for the remediation of potentially toxic elements. To this end, soil polluted with As, Cu, Hg, Pb and Sb was partitioned into various grain sizes (500–2000, 125–500 and < 125 μm). The fractions were pretreated with nZVI and subsequently subjected, according to grain size, to Wet-High Intensity Magnetic Separation (WHIMS) or hydrocycloning. The results were compared with those obtained in the absence of nanoparticles. An exhaustive characterization of the magnetic signal of the nanoparticles was done. This provided valuable information regarding potentially toxic elements (PTEs) fate, and allowed a metallurgical accounting correction considering the dilution effects caused by nanoparticle addition. As a result, remarkable recovery yields were obtained for Cu, Pb and Sb, which concentrated with the nZVI in the magnetically separated fraction (WHIMS tests) and underflow (hydrocyclone tests). In contrast, Hg, concentrated in the non-magnetic fraction and overflow respectively, while the behavior of As was unaltered by the nZVI pretreatment. All things considered, the addition of nZVI enhanced the efficiency of soil washing, particularly for larger fractions (125–2000 μm). The proposed methodology lays the foundations for nanoparticle utilization in soil washing operations.
C. Boente; Carlos Sierra; D. Martínez-Blanco; Juan Maria Menendez-Aguado; J.R. Gallego. Nanoscale zero-valent iron-assisted soil washing for the removal of potentially toxic elements. Journal of Hazardous Materials 2018, 350, 55 -65.
AMA StyleC. Boente, Carlos Sierra, D. Martínez-Blanco, Juan Maria Menendez-Aguado, J.R. Gallego. Nanoscale zero-valent iron-assisted soil washing for the removal of potentially toxic elements. Journal of Hazardous Materials. 2018; 350 ():55-65.
Chicago/Turabian StyleC. Boente; Carlos Sierra; D. Martínez-Blanco; Juan Maria Menendez-Aguado; J.R. Gallego. 2018. "Nanoscale zero-valent iron-assisted soil washing for the removal of potentially toxic elements." Journal of Hazardous Materials 350, no. : 55-65.
Soil washing is a remediation technology based on the adaptation of techniques habitually used in mineral processing to recover contaminants from polluted soils. Its main scope is the reduction of the total volume of contaminated soil, which could later be treated by biological, chemical, or thermal procedures. Since the contaminants are usually associated to the soil finer fractions, direct classification is the most widely employed technique. Moreover, other procedures, such as indirect classification, density and magnetic separation, as well as froth flotation are also extended. Soil washing is usually applied by means of on-site mobile plants which are located in the study sites. However, previously to these field applications, a detailed soil characterization and some trials are required in order to optimize the process. In this work, soils affected by heavy metals as a result of mining, metallurgical, and industrial activities are evaluated and pilot-scale treated. The diversity of soils and residues treated, together with the variety of the methodologies employed enabled the elaboration of a general feasibility protocol.
Carlos Boente; Carlos Sierra; Eduardo Rodríguez-Valdés; Diego Baragaño; José Luis Rodríguez Gallego; Juan María Menéndez Aguado. Mineral Processing Technologies for the Remediation of Soils Polluted by Trace Elements. Proceedings 2018, 2, 1458 .
AMA StyleCarlos Boente, Carlos Sierra, Eduardo Rodríguez-Valdés, Diego Baragaño, José Luis Rodríguez Gallego, Juan María Menéndez Aguado. Mineral Processing Technologies for the Remediation of Soils Polluted by Trace Elements. Proceedings. 2018; 2 (23):1458.
Chicago/Turabian StyleCarlos Boente; Carlos Sierra; Eduardo Rodríguez-Valdés; Diego Baragaño; José Luis Rodríguez Gallego; Juan María Menéndez Aguado. 2018. "Mineral Processing Technologies for the Remediation of Soils Polluted by Trace Elements." Proceedings 2, no. 23: 1458.
Francisco Pedrayes; Joaquín G. Norniella; Manuel G. Melero; Juan Maria Menendez-Aguado; Juan J. Del Coz-Díaz. Frequency domain characterization of torque in tumbling ball mills using DEM modelling: Application to filling level monitoring. Powder Technology 2018, 323, 433 -444.
AMA StyleFrancisco Pedrayes, Joaquín G. Norniella, Manuel G. Melero, Juan Maria Menendez-Aguado, Juan J. Del Coz-Díaz. Frequency domain characterization of torque in tumbling ball mills using DEM modelling: Application to filling level monitoring. Powder Technology. 2018; 323 ():433-444.
Chicago/Turabian StyleFrancisco Pedrayes; Joaquín G. Norniella; Manuel G. Melero; Juan Maria Menendez-Aguado; Juan J. Del Coz-Díaz. 2018. "Frequency domain characterization of torque in tumbling ball mills using DEM modelling: Application to filling level monitoring." Powder Technology 323, no. : 433-444.