Traditionally, Spanish schools of civil engineering provide their students a class on "Technical English" in order to develop their language skills. However, this class does not cover all the skills that the student would need in the labor market and mainly focuses in the reading and writing skills, and in a lower degree in the speaking and listening ones. This paper proposes a series of innovative and informal training activities, such as cine-forum on technical civil engineering topics and role playing on real professional situations, that allow Spanish civil engineering students to develop English skills, that can rarely be worked in the classroom (i. e. speaking, negotiating and conversing), which encourage debate, participation, and foster their self-confidence to speak about technical-English topics in public. Although the students' level of English is much lower than expected, they all agree on the importance of technical English for their future career. The results also show the students' lack in skills that are difficult to train in regular classes (speaking and talking). Consequently, this situation would require to provide complementary activities like the ones suggested in this project in order to develop these skills and increase the students' demand for engineering classes taught in English.
ResumenLa fluorita es un mineral de mucha importancia en la industria metalúrgica. Se presenta acompañada de silicatos, carbonatos y óxidos. Para la obtención de concentrados comerciales, más de 95 % de CaF 2 , el mineral se procesa en plantas de flotación donde se usa ácido oleico como colector de la fluorita. Para que el ácido oleico actúe selectivamente es común el uso de reactivos depresores: silicato de sodio, tanino y carbonato de sodio. Estos agentes tienen un efecto dispersante que se evidencia en la separación de sólido-líquido sobre las colas de las plantas. El agua recuperada contiene finos que al ingresar al circuito afectan notoriamente la eficiencia de la flotación. Se estudió el efecto de iones coagulantes para clarificar el agua de retorno. El problema de estos iones está relacionado con sus reacciones con el colector por la formación de compuestos y, posiblemente, sobre la selectividad. Se agregaron cantidades variables de iones Al 3+ , Fe 3+ y Ca 2+ y se evaluó la recuperación de fluorita, la selectividad y en el contenido de sóli-dos en el agua de los efluentes. Los resultados muestran que algunos iones no solamente no mejoran la calidad del agua sino que además son perjudiciales en la flotación. Otros, por el contrario, contribuyen a reducir el contenido de finos en suspensión. Por lo tanto, y si bien hay una pérdida en la recuperación, este efecto se puede contrarrestar con un pequeño aumento en el consumo de colector. Palabras claveFlotación; Fluorita; Reactivos; Lamas; Coagulación. Coagulation of fines in fluorite froth flotation AbstractFluorite, a valuable mineral in the metallurgical industry, can be found together with silicates, carbonates and oxides in ore deposits. Commercial concentrates with more than 95 % of CaF 2 are obtained processing the mineral in flotation plants and using oleic acid as fluorite collector. Depressor reagents such as sodium silicate, tannin and sodium carbonate are commonly employed to allow the oleic acid selective performance. These reagents cause a dispersant effect separating the solid-liquid solution on tailing plants. Fine particles in the recovered water enter the circuit and affect the flotation efficiency. The effect of coagulant ions was studied as a method to clarify the returned water. The problem of the presence of these ions is related to its reactions with the collector by the formation of compounds and possibly on the selectivity. Variable quantities of Al 3+ , Fe 3+ and Ca 2+ ions were added to the flotation to evaluate its effect on the fluorite recovery, in the selectivity and in solids content in recirculation water. Results show that some ions fail to improve water quality and are detrimental to flotation. On the contrary, some ions contribute to reduce fine content in suspension. Therefore, although there is a recovery reduction, such effect can be counteracted increasing the collector consumption a little.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.