Study of the chemical behavior during the ring formation of clinker in cement plant. / Estudo do comportamento quÃmico durante a formaÃÃo de anÃis de clÃnquer em fÃbrica de cimento.
AUTOR(ES)
Jailson Mathias de Souza
DATA DE PUBLICAÇÃO
2009
RESUMO
The formation of thick collages in firing zone furnace of clinker in cement plants, called clinker ring, is a phenomenon that creates economical and environmental disorders. To remove the clinker ring it is necessary to cool up the oven for 24 hours cutting it with a breaking machine. This process is dangerous and highly cost-consuming, since the furnace fails when producing for about five days and, after removal, it is necessary to heat the furnace with expensive fuel oil. The causes of formation of rings are divided into chemical and operational aspects, and there are several possible causes within these two groups. This work is focused on the formation of rings due to the chemical appearance. So, this work aimed to study the formation of clinker rings and propose improvements in order to minimize and / or eliminate the formation of these rings, to obtain a process with improved operational stability, greater sustainability, economy of fossil fuels and gains in reducing CO2 emissions, the main responsable of the greenhouse effect. The chemical behavior during the formation of clinker rings in the cement factory Camargo Correa Cements, in the Ijaci-MG city during the furnace stop form February 3rd to February 10th 2007, has been studied. Clinker samples were collected four days before stopping furnace due to the ring formation, and four days after starting the furnace without the ring formation, which were subjected to analysis of the reflected light optical microscopy, chemical analysis by x-ray fluorescence (XRF) with calculations of the fitness factor for collage formation (AW), burning factor (BF), percentage of liquid phase, silica module (MS) and alumina module (MA). Collages ring samples are also been collected. These samples were submitted to wet chemical analysis and x-ray diffraction (XRD). In addition, fuel samples were collected and submitted to analysis of lower calorific value (LCV), ash content and particle size in 170-mesh sieve. The results showed that, with regard to the chemical aspect, the ring formation is related to the low viscosity of the liquid phase of clinker during formation which, in turn, is linked to the relationship between the aluminum oxide (Al2O3) and iron oxide (Fe2O3), also known as MA, whose ideal values were those exceeding 1.80. The values found in AW, BF and percentage of liquid phase, described in the literature, were not found as efficient parameters for the non-formation of ring. The XRD and wet chemical analysis of the ring showed that the ring formed is a clinker one and not sulfate. Through the analysis of microscopy it was possible to verify that the furnace was operating in an oxidizing environment. The analysis of fuel samples suggest that operates with a fuel with a less than 2.5%.
ASSUNTO(S)
1. liquid phase. 2. ring. 3. bonding 1. fase lÃquida. 2. anel. 3. colagem quimica
