Reduction of marble waste landfills through the enhancement of CaCO3

The purpose of this research is to show how to reduce the amount of landfilled marble waste/scraps by collecting and re-purposing the marble microfine sawdust, which is produced after the sawing and processing of carbonate dimension stones. Our ultimate goal is to identify alternative uses, rather than landfilling. The current solution so far preferred - landfill - does not fully meet sustainable development criteria. Our reduction strategy is based on a regulatory framework which identifies waste, by-product and end of waste status clearer. After a careful characterization, the marble sawdust can be reused and marketed for industrial applications, that employ micronized calcium carbonate, as a new material. During the first few years of study, the research focused on the construction industry (i.e. concrete - plaster - brick), by assessing the extensive use of marble sludge. The building industry is able to incorporate and reuse waste materials deriving from different industries, although, in this way, such material would be regarded as of poor quality. The current trend is to add high economic value to this waste. Since product specifications for calcium carbonate vary depending on its application, a comparison with the paper - rubber - and tyre calcium carbonate requirements is described herein and, in addition, the final results of the tests carried out on marble sawdust in tyre mixtures are also reported in detail.