Estudo de viabilidade do uso de areia residual da produção de silicato de sódio no processo produtivo

Abstract

Sand is the main raw material used in the production of sodium silicate. However, the sand waste generated by the silicate industries is a constant and significant problem, with an average annual disposal of 142 tons. Therefore, it is necessary to promote the reduction of this waste through available practices for proper disposal or, when possible, reuse it, given that it can cause negative impacts on the environment. In addition, reusing sand also has the benefit of reducing production costs, since it can be reincluded in the process without compromising yield. In this sense, it is of great relevance to create sustainable solutions capable of efficiently addressing the social, environmental and economic challenges involved and which can be applied in industries. The aim of this work was to evaluate the reuse of this industrial waste and study its reuse in new reactions aimed at the production of sodium silicate. For this purpose, the residue was subjected to a washing process, followed by titrimetric tests, in triplicate, to determine the Na₂O content in the water washing, using 2.0N HCl as titrant, resulting in an average value of 12.80%. X-ray fluorescence tests were also performed on the solid part after washing, indicating a SiO₂ percentage of 99.009%, a value comparable to that of virgin sand, whose SiO₂ content varies between 98.00% and 100.00%, which demonstrates that the results obtained in the residue presented satisfactory results. Based on a formulation suggested in this research, it can be concluded that the reuse of sand in the sodium silicate production process could promote a cost reduction of R$9,870 per batch, representing an annual saving of R$259.670,4, integrating sustainable practices and cost reduction in silicate production.