OPTIMIZATION OF SILVER CEMENTATION YIELD IN FIXED BED REACTOR USING FACTORIAL DESIGN AND CENTRAL COMPOSITE DESIGN

This work deals with cementation of silver onto iron grid in fixed bed reactor. The influence of several parameters is studied namely: initial concentration of silver [Ag+](0), flow rate, solution pH, and mass of iron. Moreover, their influence on the yield of the reaction of cementation is investigated statistically by the experimental design in view of industrial application. The estimation and the comparison of the parameter's effects are realised by using two-level factorial design. The analysis of these effects permits to state that the most influential factor is the mass of iron with an effect of (+5.642), the second in the order is the initial concentration of silver ions (Ag+) with an effect of (+4.005), the third is the flow rate of the electrolytic solution with an effect of (+3.824). A central composite design methodology is employed to determine the optimum conditions for a silver cementation yield onto iron grid. For this end, the experimental results were approximated by a second-order model as well as the surface contour plots and surface responses are drowned. The optimal conditions found for initial silver concentration, such as a flow rate, pH of the solution and mass of iron, are respectively: 21.25 mg/L, 4.43 L/min, 3.6 and 50 g. Under these conditions, the obtained silver cementation yield is 96.851%.