Evaluation of the contents of ornamentals stones wastes and vegetable polyurethane resin in the production of engineered stones

The production of ornamental stones in Brazil has been increasing over the years. As a consequence, waste generation also increases. The objective of the present work was to evaluate the influence of different contents of ornamental stone wastes and vegetable polyurethane resin in the production of eco-efficient engineered stones. Initially, the characterization of the waste was carried out through the technique of X-ray fluorescence and X-ray powder diffraction. Subsequently, the engineered stone slabs were produced through the vacuum vibration and compression method, using quartzite waste as natural aggregate and vegetable polyurethane resin in the contents of 6, 8, 10, 12, and 14 wt%. The slabs were submitted to water absorption, porosity, density, mechanical resistance, scanning electron microscopy (SEM), and petrography tests. The results indicated that increasing the resin content decreased the apparent density, water absorption, and porosity of the engineered stones. The engineered stones produced with 10 wt% resin showed the best results, with greater flexural strength and acceptable density, water absorption, and porosity indices. Resin contents below 10% resulted in porous slabs, while contents above 10 wt%, the slabs showed elastic behavior and the presence of fractures and bubbles. Therefore, the use of these wastes for the manufacture of eco-efficient materials can contribute to the circular economy and can help to solve one of the biggest problems of the ornamental stone sector, and consequently, to reduce the negative environmental impact, can add value to the waste and contribute to sustainable development. [Display omitted] •Engineered stones were produced with ornamental stone waste and PU resin.•The contents vegetable polyurethane resin in the engineered stones was investigated.•Microstructure and petrographic analysis were performed.