Use of industrial wastes as opacifiers in porcelain tile bodies

The present research was conducted to assess the feasibility of using two kinds of industrial wastes as pacifiers in porcelain tile bodies, as well as to define what pre-treatment would be required to prepare the wastes for such use. The characteristics of the wastes were analysed, first, to determine their chemical and mineralogical composition, as well as their behaviour when subjected to heat, in order to identify any undesirable substances and to establish suitable conditions for removing these with simple methods. This allowed suitable materials to be obtained for use in porcelain tile compositions. The effects were then studied of the incorporation of these pre-treated waste materials on porcelain tile characteristics. The results obtained indicate that the two waste materials used in this research have a significant opacifying capability, which makes them of great interest as possible raw materials for products that are not required to have maximum whiteness values. The only drawback detected in one of these wastes was that the porcelain tile composition needed to be slightly adjusted in order to ensure that its behaviour during firing did not change.