Thermal exploitation strategies for paper mill waste

One of the main problems of our society is the high generation of wastes that are currently discharged to landifill, causing environmental and economic issues. On this basis, from a circular economy perspective, it is urgent the development of sustainable strategies for valorizing these materials. In this context, the papermaking industry produces a large amount of inorganic-rich sludges which, at the moment, are exploited for agricoltural application, for energy recovery and/or for the production of bio-composites. However, the above possibilities do not valorize each fraction of the starting feedstock, which includes inorganic and organic components, opening the way towards more promising strategies of fractionation and exploitation. In this perspective, the present investigation studied thermal treatments for the fractionation of inorganic sludges. The aim of this study is the recovery of the calcium carbonate, the main component of the inorganic sludge, that could be reused as filler in different materials.