Recovered slate waste as raw material for manufacturing sintered structural tiles

Since roofing slate exploitations generate large quantities of slag from the quarry and mud from the cutting tools, special efforts are needed to avoid associated environmental hazards, such as floods and the unsightliness of slag-heaps. Recovering this mud and slag as raw material for manufacturing sintered structural parts could be a response to the demand. This study, which includes a characterisation of the material and an evaluation of the final properties, examines the raw material and its behaviour during compaction to determine whether it is suitable for processing by powder technology. A mineralogical characterisation by chemical analysis and X-ray diffraction, together with a thermal analysis, provided the data of the sintering process. The properties of the sintered samples were checked by: density, dimensional change, volume loss, mass decrement, three-point bending strength, water absorption and permeability, and wear behaviour trying to guarantee their behaviour.