Caracterización de una mezcla de moldeo tipo única con elementos refractarios
Fecha
2019
Autores
Moya Rodríguez, Luis Alejandro
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Editor
Universidad Central ``Marta Abreu`` de Las Villas. Facultad de Ingeniería Mecánica e Industrial. Departamento de Ingeniería Mecánica
Resumen
En la empresa Planta Mecánica la fabricación de piezas como resultado de la fundición ha disminuido notablemente en los últimos años, no sin dejar de ser una de las principales formas de producción. En este proceso se utilizan mezclas que varían en sus propiedades y composición, de acuerdo a la utilización para la cual se tenga prevista, como MC-3 (Moldes con terrajas), MCE-4 (Piezas grandes de acero), MR-1 (Mezcla única), esta última mezcla está compuesta por bentonita y melaza como aglutinantes, acompañando a la arena sílice. La utilización de esta mezcla ha quedado relegada en los últimos tiempos debido al empleo de la melaza como alimento animal. En este trabajo se realiza una caracterización de una mezcla de moldeo tipo única con la utilización de aditivos refractarios, productos de la molienda de ladrillos de chamota, desechados en las reparaciones de los hornos de la empresa. Para su confección se tuvo en cuenta una distribución similar a la mezcla MR-1 sustituyendo la melaza por dicho aditivo. Para ello, primeramente, se realizó el diseño de experimento para una mezcla con dos componentes y dos respuestas, donde se mantuvo contante la arena sílice y se variaron los porcientos del aditivo refractario y de bentonita, con el objetivo de determinar la mejor relación arena-aditivo-bentonita. El primer procedimiento fue determinar la granulometría de la arena sílice para establecer una similar en el producto refractario. Se realizaron diversos ensayos, entre ellos, determinación de la resistencia en verde y en seco, el porciento de humedad y la vida de banco. Los resultados de los experimentos arrojaron que la mezcla con mejores propiedades es la que tiene una relación (1 a 9). Se realizó una prueba real con esta mezcla, utilizando una aleación de aluminio, donde se apreció un excelente resultado.
In the company Planta Mecánica, the manufacture of pieces as a result of the smelting has diminished remarkably in the last years, not without ceasing to be one of the main forms of production. In this process, mixtures that vary in their properties and composition are used, according to the usage for which it is planned, such as MC-3 (Molds with dies), MCE-4 (Large pieces of steel), MR-1 (Single mix); this last mixture is composed of bentonite and molasses as cohesive, accompanying the silica sand. The usage of this mixture has been relegated in recent times due to the use of molasses as animal feed. In this project, a characterization of a single type molding mixture is made, with the use of refractory additives, products from the grinding of chamotte bricks, discarded in the repairs of the company's ovens. For its preparation, a distribution similar to the MR-1 mixture was taken into account, replacing the molasses with this additive. For this, firstly, the experimental design was made, for a mixture with two components and two answers, where the silica sand was kept constant and the percentage of the refractory additive and bentonite were varied, in order to determine the best sand-additive-bentonite relation. The first procedure was to determine the granulometry of the silica sand to establish a similar one in the refractory product. Several tests were carried out, among them, the determination of the resistance in green and dry, the percentage of humidity and the life of the bank. The results of the experiments showed that the mixture with the best properties is the one with a relation (1 to 9). A real test was carried out with this mixture, using an aluminum alloy, where an excellent result was appreciated.
In the company Planta Mecánica, the manufacture of pieces as a result of the smelting has diminished remarkably in the last years, not without ceasing to be one of the main forms of production. In this process, mixtures that vary in their properties and composition are used, according to the usage for which it is planned, such as MC-3 (Molds with dies), MCE-4 (Large pieces of steel), MR-1 (Single mix); this last mixture is composed of bentonite and molasses as cohesive, accompanying the silica sand. The usage of this mixture has been relegated in recent times due to the use of molasses as animal feed. In this project, a characterization of a single type molding mixture is made, with the use of refractory additives, products from the grinding of chamotte bricks, discarded in the repairs of the company's ovens. For its preparation, a distribution similar to the MR-1 mixture was taken into account, replacing the molasses with this additive. For this, firstly, the experimental design was made, for a mixture with two components and two answers, where the silica sand was kept constant and the percentage of the refractory additive and bentonite were varied, in order to determine the best sand-additive-bentonite relation. The first procedure was to determine the granulometry of the silica sand to establish a similar one in the refractory product. Several tests were carried out, among them, the determination of the resistance in green and dry, the percentage of humidity and the life of the bank. The results of the experiments showed that the mixture with the best properties is the one with a relation (1 to 9). A real test was carried out with this mixture, using an aluminum alloy, where an excellent result was appreciated.
Descripción
Palabras clave
Empresa Planta Mecánica, Santa Clara, Fabricación de Piezas, Mezclas de Moldeo, Procesos de Fundición, Elementos Refractarios