Abstract

The disposal of finished leather waste (FLW) has always been a concern of the tanning industry. In this paper, the finished leather degradation solution (LDS) was obtained from the alkali-heat degradation of FLWat an 84.4% extraction rate. The solid Collagen Degradation Product (CDP) of LDS contains 47.1mg/kg of chromium. When the LDS was used for gypsum retardation, with the dosage of LDS increased, the setting time of gypsum was gradually prolonged. XRD, TGand FTIR analysis indicated that the hydration reaction of gypsum hemihydrate was inhibited after adding LDS. SEM observation showed that the crystal morphology of gypsum dihydrate changed from needle-like to columnar when the 1mL 25% LDS was introduced. This study not only indicated that LDS obtained from FLW can be a new material for gypsum retardation but also provided a new way to deal with finished leather waste.