Obtención pirometalúrgica de un Cermet a partir del sistema ternario cola - almidón - aluminio
Fecha
2016-06
Autores
Sánchez Castro, Liesly
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Editor
Universidad Central “Marta Abreu” de Las Villas. Facultad de Química Farmacia. Departamento de Licenciatura en Química
Resumen
Durante el transcurso de este proyecto las colas de desechoprocedentes del proceso siderometalúrgico efectuado en la Planta Pedro Soto Alba (PSA) de Moa, serán utilizadas como objeto de estudio en la determinación de algunas de sus propiedades tanto química, físicas, como mecánicas.Las mismas se pretenden usar como materia prima durante la elaboración de un material de alta prestación tipo cermet. El diseño de dicho material se realizará a partir de una mezcla aluminotérmica basada en proporciones estequiométricas, regidas por un balance de masas confeccionado en Excel. Un estudio efectuado a colas arrojó los resultados siguientes: densidad picnométrica aproximada 2,98 g/ml, porosidad 29,85 %, y una baja densidad aparente 0,89 g/ml. Para la elaboración del Cermet, se realizaronvarias pastillas, constituidas por una proporción estequiométrica basada en: 45,00 g de colas, 27,48 g de aluminio en polvo y 10,68 g de almidón prensadas a 40 MPa aproximadamente durante 5 min cada una de ellas. Posteriormente las pastillas se someten a un primer tratamientotérmico que se realiza de forma escalonada a 250 °C, 350 °C, 450 °C, 550 °C, por un tiempo en cada escalón de 2 h, donde se evidencia una reacción exotérmica violenta de (oxidación-reducción) y las pastillas se deforman en un fundido de color oscuro. El preproducto se tritura y se elabora a partir del mismo nuevas pastillas. Estas pastillas se someten a un segundo tratamiento térmico durante 8 h a 900 °C, donde no se producen reacciones químicas apreciables, y no se deforman. Una vez que culmina el tratamiento térmico se toma la muestra y se prepara en tres fases, comenzando por un desbaste grosero, seguido un desbaste final, y luego por un pulido, todo con el propósito de determinar las características estructurales o de constitución de la muestra y así relacionarlas con las propiedades físicas, mecánicas y químicas de las mismas, por medio del uso de un Microscopio Óptico Metalográfico. Luego se procede a determinar por medio de un MicrodurómetroShimadzu la microdureza de la muestra, la cual arrojó los resultados siguientes: 1043 Hv aproximadamente, lo que nos da un indicio de la existencia de carburos metálicos en el seno de la muestra obtenida, lo cual le confiere a estauna elevada dureza.
During the course of this project queues waste from the hydrometallurgical process carried out in the Plant Pedro Soto Alba (PSA) Moa, will be used as a study in determining some of their much chemistry, physical properties such as mechanical, the same is intended to be used as raw material for the production of high performance material type (Cermet). The design of such material is made from a thermite mixture based on stoichiometric proportions, governed by a mass balance made in Excel. Queues A study yielded the following results: picnométrica approximate density 2.98 g / ml, porosity 29.85%, and a low bulk density 0.89 g / ml. To prepare the cermet, various pills were performed, consisting of a stoichiometric ratio based on: 45.00 g of queues, 27.476 g of aluminum powder and 10.68 g of starch pressed at about 40 MPa for 5 min each they. Subsequently the tablets are subjected to a first heat treatment is performed in stages to 250 ° C, 350 ° C, 450 ° C, 550 ° C, for a time at each step of 2 hours, where a violent exothermic reaction was evident of (oxidation-reduction) and the pellets are transformed into a molten dark, once you get this pre-product proceeds to shred it and other pills that pre-product obtained dark are developed based. These new pads are subjected to a second heat treatment for 8 h at 900 ° C where no significant chemical reactions occur, and lozenges not deform. After the second heat treatment completed the obtained sample is taken and is prepared in three phases, starting with a coarse roughing, followed by a final roughing, then by a polished, all for the purpose of determining the structural characteristics or constitution of the sample and thus relate the physical, mechanical and chemical properties thereof, by use of an optical microscope Metallographic. Then proceed to determine by a Microdurometer Shimadzu the microhardness of the sample, which yielded the following results: 1043 Hv approximately, which gives us an indication of the existence of metal carbides within the sample obtained, which this gives a high hardness.
During the course of this project queues waste from the hydrometallurgical process carried out in the Plant Pedro Soto Alba (PSA) Moa, will be used as a study in determining some of their much chemistry, physical properties such as mechanical, the same is intended to be used as raw material for the production of high performance material type (Cermet). The design of such material is made from a thermite mixture based on stoichiometric proportions, governed by a mass balance made in Excel. Queues A study yielded the following results: picnométrica approximate density 2.98 g / ml, porosity 29.85%, and a low bulk density 0.89 g / ml. To prepare the cermet, various pills were performed, consisting of a stoichiometric ratio based on: 45.00 g of queues, 27.476 g of aluminum powder and 10.68 g of starch pressed at about 40 MPa for 5 min each they. Subsequently the tablets are subjected to a first heat treatment is performed in stages to 250 ° C, 350 ° C, 450 ° C, 550 ° C, for a time at each step of 2 hours, where a violent exothermic reaction was evident of (oxidation-reduction) and the pellets are transformed into a molten dark, once you get this pre-product proceeds to shred it and other pills that pre-product obtained dark are developed based. These new pads are subjected to a second heat treatment for 8 h at 900 ° C where no significant chemical reactions occur, and lozenges not deform. After the second heat treatment completed the obtained sample is taken and is prepared in three phases, starting with a coarse roughing, followed by a final roughing, then by a polished, all for the purpose of determining the structural characteristics or constitution of the sample and thus relate the physical, mechanical and chemical properties thereof, by use of an optical microscope Metallographic. Then proceed to determine by a Microdurometer Shimadzu the microhardness of the sample, which yielded the following results: 1043 Hv approximately, which gives us an indication of the existence of metal carbides within the sample obtained, which this gives a high hardness.
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Materiales Compuestos, Planta Pedro Soto Alba (PSA), Moa, Oriente, Mezcla Aluminotérmica, Cermet