Mathematical model of goethite synthesis by oxyprecipitation of steel pickling liquors

Abstract The aim of this paper is to study the synthesis of goethite by means of oxyprecipitation of sulphuric steel pickling liquors. The selected variables are pH, stirring velocity and flow of oxygen as oxidizer agent, a mathematical model of this synthesis being proposed from the experimental design. The model has validity in the variables' intervals. An analysis of residuals, a plot of predicted vs. observed values and an analysis of variance of the model are carried out as diagnostic probes. Posteriorly, the influence of the variables and their optimum values are determined for obtaining high quality goethite.