Due to the raw materials used in the ceramic sanitary ware industry, wastewater with high heavy metal and suspended solids content is formed. These wastewaters need to be treated in order to be reused or discharged to the receiving environment. At the same time, a high amount of plaster mold wastes is formed due to the process of the sector. In this study, it was planned to use waste plaster molds in the treatment process, to bring them into circular economy and to reduce the treatment costs by optimizing the coagulation-flocculation processes. Experimental design methods are often used to optimize processes. For this reason, in the study, the wastewater treatment of the ceramic sanitaryware industry was optimized using the Response Surface Method by using different chemical coagulants. Alum, Iron (III) Chloride, Polyaluminum Chloride (PAC) and plaster mould wastes were used as coagulants in the experiments. The effects of coagulant dose and pH used for Chemical Oxygen Demand (COD) and Suspended Solids (SUD) removal efficiency on each coagulant wastewater were investigated. Classic jar test experiments were performed with 2 min. 120 rpm fast mixing, 30 min. 30 rpm slow mixing and 60 min. applied in the form of precipitation. Anionic polyelectrolyte used as flocculation auxiliary was taken as 0,5 g/L for all chemicals. As a result of the optimization studies, the optimum conditions were determined as follows; For alum; pH:9, dose:4 g/L, for Iron (III) Chloride; pH:7, dose:3.4 g/L, for PAC; pH:9, dose:6 mL/L, for waste plaster mould; pH: 7 doses: 16 g/L. Under these optimum conditions, the COD removal efficiencies for Alum, Iron (III) Chloride, PAC and waste plaster mould were found to be 72.6%, 78.4%, 73.6% and 71.3%, respectively. In the experiments carried out under the same conditions, the removal efficiencies of AKM were obtained as 98.2%, 95.1%, 99.1%, and 93.5% for alum, iron (III) chloride, PAC and waste plaster mould, respectively. It has been observed that waste plaster molds can be used as a coagulant in the waste water treatment process of ceramic sanitary ware, thus providing an alternative waste recovery method for the ceramics industry.