Characteristics of the raw materials used by the companies of the ceramic sector of the metropolitan area of Cucuta (Colombia)

The metropolitan area of Cucuta (Colombia) is characterized by a conglomerate of companies dedicated to the manufacture of ceramic building materials. The zone of influence is rich in clay materials, limestones and feldspars which are the fundamental raw materials of the manufacturing process. A process of characterization of these materials was carried out in order to know the differentiating aspects that allow the decision making at the moment of formulating ceramic pastes. X-ray diffraction, X-ray fluorescence, calcimetry, thermal gravimetric analysis and differential scanning calorimetry were used for the recognition of natural materials. The hydrometer technique for granulometric analysis was also used to establish the suitability of clays for use in construction ceramics. In addition, the percentage of water absorption, firing shrinkage and mechanical resistance to flexion were monitored as indicators of the vitrification capacity of each evaluated clay material (at 1080 degrees C and 1140 degrees C). It was identified that clay materials are characterized by the presence of phyllosilicate minerals such as kaolinite and muscovite. They have low contents of carbonates and sulfur compounds. The results obtained show that, the greater prevalence of potassium and iron content (presence of muscovite) in clay materials seem to have a favorable influence on the technological properties evaluated in construction ceramics. The characterization tests of the limestone and feldspars allowed to recognize their purity and to establish possible influences in the ceramic process according to the found composition. (C) 2018 SECV. Published by Elsevier Espaila, S.L.U.