187,029 research outputs found
Beneficiation of concentrated ultrafine suspensions with a Falcon UF concentrator
No full textFalcon concentrators are enhanced gravity separators designed for concentrating fine particles. The Falcon UF model is unique in that it is dedicated to beneficiation of ultrafines, one key feature being that it does not make use of any fluidization water. We investigated the physics of particle transport inside Falcon concentrators, and concluded that separation efficiency is governed by differential settling velocity. We derived and published a predictive model of the partition function under dilute conditions. We intend to extend the initial model to concentrated ultrafine suspensions for application to industrial scenarios by adding hindered settling to account for solid concentration effects
Fluid dynamics based modelling of the Falcon concentrator for ultrafine particle beneficiation
No full textEnhanced gravity separators are widely used in minerals beneficiation, as their superior gravity field enables them to separate particles within narrow classes of density and size. This study aims to shed light on the Falcon concentrator’s ability to separate particles within size and density ranges lower than usual, say 5 to 60 μm and 1.2 to 3.0 s.g. respectively. As differential particle settling is expected to be the prevailing separation mechanism under such conditions, this study presents the workings of a predictive Falcon separation model that embeds phenomenological fluid and particle flow simulation inside the Falcon’s flowing film. Adding to the novelty of modelling the Falcon concentrator
using a fluid mechanics approach, one point of practical significance within this work is the derivation of the Falcon’s partition function from fluid flow simulation results
Physical analysis and modeling of the Falcon concentrator for beneficiation of ultrafine particles
No full textA predictive model of the Falcon enhanced gravity separator has been derived from a physical analysis of its separation principle, and validated against experimental data. After summarizing the previous works that led to this model and the hypotheses on which they rely, the model is extended to cover a wide range of operating conditions and particle properties. The most significant development presented here is the extension of the analytical law to concentrated suspensions, which makes it applicable to actual plant operating conditions. Two examples of industrial use cases are described and studied by interrogation of the model: dredged sediment waste reduction and coal recovery from fine tailings. Comparisons with empirical studies available in the literature show a good agreement between model predictions and industrial data. The model is then used to identify separation efficiency limitations as well as possible solutions to overcome them. These two examples serve to show how this predictive model can be used to obtain valuable information to improve physical separation processes using a Falcon concentrator, or to evaluate Falcon separator’s abilities for new applications
Experimental validation of a fluid dynamics based model of the UF Falcon concentrator in the ultrafine range
No full textThe process of separating ultrafine particles, say below 80 μm, on the basis of density is a true technical challenge. Indeed, the separation process itself becomes very much size dependent with such fine particles, so that large enough density differentials are necessary for offsetting the strong particle size effect. Our study is concerned with understanding the limitations of the UF Falcon concentrator, an enhanced gravity separator specifically designed for treating slurries with ultrafines. To this end, based on a number of hypotheses, we have already derived and published a theoretical model of the UF Falcon concentrator for treating dilute suspensions. This paper presents the validation and calibration of this model, based on experimental measurements carried out under controlled conditions using a laboratory scale concentrator. By comparing measured and predicted separation results for particles with known size distribution and density, the work validates the key model hypotheses, thereby confirming our understanding of the physics of the separation process. Moreover, by changing operating conditions in a systematic manner, the work is able to calibrate the model so that it can be used to make quantitative prediction of the UF Falcons performance
Falcon, Hector G.
No full textCentro Asturiano membership record of Hector G. Falcon; Socio Number: 127953.https://digitalcommons.usf.edu/asturiano_membership/2398/thumbnail.jp
CASTRO, Andrés G. (Dr.)
No full text"Dr. Andrés G. Castro congratulates Fernando Torreblanca, Undersecretary of Foreign Affairs on his birthday, wishes him a speedy recovery, and the best of success on his official career in Europe.
/ El Dr. Andrés G. Castro felicita a Fernando Torreblanca, Subsecretario de Relaciones Exteriores, por su onomástico y le desea su pronto restablecimiento y éxito oficial en Europa.
CASTRO, Alejandro G.
No full textLetter from Mr. Alejandro G. Castro, Principal Administrator of the Fiscal Stamp in Culiacán, to Gen. Alvaro Obregón apologizing for not attending a banquet as he is sick. File C-40 / Carta del Sr. Alejandro G. Castro, Administrador Principal del Timbre en Culiacán al Gral. Alvaro Obregón, disculpándose de asistir a un banquete por estar enfermo. Exp. C-4
Il tesoro della cattedrale di Agrigento: capolavori d'arte decorativa dal XII al XIX secolo
No full text5. Il tesoro della cattedrale di Agrigento: capolavori d'arte decorativa dal XII al XIX secolo, pp. 25-36, in G. COSTANTINO- E. DE CASTRO-G. CIPOLLA (a cura di), Museo della cattedrale di Agrigento: storia delle collezioni dall'istituzione storica al museo diocesano, Edizioni Lussografica, Caltanissetta 200
CASTRO, Andrés G. (Dr.)
No full text"Dr. Andrés G. Castro congratulates Fernando Torreblanca, Undersecretary of Foreign Affairs on his birthday, wishes him a speedy recovery, and the best of success on his official career in Europe.
/ El Dr. Andrés G. Castro felicita a Fernando Torreblanca, Subsecretario de Relaciones Exteriores, por su onomástico y le desea su pronto restablecimiento y éxito oficial en Europa.
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