Properties of geopolymers produced with sugar press filter waste and fly ash under certain curing conditions

Abstract

During the sugar production process, hydrated lime in the consistency of limewash is mixed with the raw juice and the colloidal substances in it are precipitated. The excess lime added to the juice is removed from the juice with the help of CO2 in the carbonation boilers. The sludge part of the sludge taken here is settled in decanters and filtered with the help of press filters. The waste that contains approximately 80% dry matter from press filters is called “Press Filter Waste” (PFW). Study was executed on the recycling of PFW which is released during this process. Geopolymer samples containing fly ash (FA) and PFW were obtained by using alkaline activators. In study, samples were produced with standard sand, FA, sodium silicate (Na2SiO3), PFW and water (S). Samples were prepared as sand/binder ratio 3.0, H20/binder ratio 0.19, 0.17 and H20/Na2SiO3 ratio 0.386, 0.341 and were cured at 120 °C. It has been observed that PFW10FA90S2T samples have the highest compressive strength for 28 days (23.68 MPa), while the PFW30FA70S2T samples have the lowest compressive strength (21.00 MPa). When the 28-day unit weights of the samples were evaluated, it was determined that the PFW10FA90S2T samples have the highest unit weight (1.950 kg/dm3).