The high energy demands of thermal treatments, the emission of harmful gases such as NOx during the thermal and nitric acid dissolution treatments, and the waste solutions of the nitric and solvent dissolution treatments are the major environ- mental concerns for industrial application of the three types of delamination methods. Therefore, improvements in energy bal- ance of thermal treatments, emission control and treatments of thermal and nitric acid dissolution, as well as the waste solution treatments of nitric acid and solvent dissolution should be further studied.