Statistical analysis of laboratory results of Zn wastes leaching

In Spain, several kinds of zinc-containing waste materials are available for zinc recovery. Zn residue leaching studies were carried out using a central composition design of experiments to show the application of statistical analysis to the results obtained. Ammonium carbonate (3M)–ammonia solutions were used for leaching. Zn recovery yields are >95% for this kind of waste material. A regression equation for the dissolution of zinc was developed as a function of temperature, pH and solids concentration. All the parameters were varied at two levels for designing experiments and two base levels and six outer levels experiments were carried out to estimate error and consider second order relationships among the variables.