Design and Assessment of a Dual Stage Crusher for Gypsum Recovery From Plasterboard Residue Recycling

Plasterboards, agricultural additives, and partial concrete substitutes all use gypsum as an essential raw material. Although gypsum is widely used in many sectors in the Philippines, there are currently no technologies available for its recovery. The eventual generation of waste resulting from using gypsum boards calls for the urgent development of effective recycling and disposal methods. This study aims to develop an efficient gypsum-extracting machine for plasterboard residue recycling. The machine consists of two stages of roll crushers, comprising smooth and toothed roller crushers. The system recovered 16.65 kg of crushed gypsum plaster out of 18 kg of clean plasterboard waste, resulting in a recovery rate of 92.50 %. Losses of no more than 7.5 % were also verified the percentage of mass per trial. It was found that there is a significant effect of the type of feed (p=0.000) and incorporation of the first stage of rollers (p=0.002) on the feed rate. The distribution of the particle size for the crushed plaster was also clustered and analyzed, considering the type of feed and the condition of the first stage of crushing. The results also show that the particles of the crushed gypsum plaster greater than 3 mm have the highest mass average percentage of 37.63 %, while particle sizes close to 1.4 mm have the least value with 4.82 %.