This paper is a review of the refining and purification processes in Al and Al alloy. Firstly, the authors introduce fluxing, floatation, and filtration process as fundamental processes of removing impurity from Al. Secondly, they introduce sedimentation, distillation, liquidation process as recent technologies. Thirdly, they introduce three-layer electrolysis and segmentation methods as processes to obtain high purity Al. Finally, they explain the purification process of Al-Mg alloys. Al and Al alloys are prospective materials because of their light weight, and the comprehensive review of their purification processes are important. Regarding the purification of Al, major processes are described sufficiently. As shown below, however, the objective of this review is not clear. The structure of this manuscript is not well organized. I think that the authors need clarify the objective of this review and restructure the manuscript fundamentally. Thus, my recommendation is major revision.

• According to the title in this manuscript, the main theme is Al alloy with focus on Al-Mg series. However, in abstract, main text, and conclusion section, most of the description is about pure Al.

• In introduction section, the objective of this review is not described clearly. In the first paragraph, the authors explain the importance of Al-Mg alloys. However, most of the main content is composed of the explanation of purification of pure Al. In the third paragraph, although the authors explain some purification process, such as fluxing, floating, and filtration, they should be explained in the main content. As a result, I didn’t understand the objective of this review.

• Standard process to obtain high purity Al is the combination of Hall-Heroult technique, three layer electrolysis, and segregation as described in figure 4. When are the other process, such as fluxing, floatation, filtration, sedimentation, and distillation technologies used, and how are they related to the standard process? The authors should describe the relation between different processes and compare the pros and cons.

• Required purity level depends on the application. The authors should describe the application of pure Al and their specifications requirement. In addition, the authors should describe the material flow of Al. For new production and recycle from scrap, is the purification process the same? The authors should describe the entire picture on Al purification technology.

• The title says “with focus on Al-Mg series”. However, it is difficult to understand the entire picture on Al-Mg series from this manuscript. What is the application of Al-Mg alloy? What is the standard production and purification method of Al-Mg alloy? How is the material flow of Al-Mg alloy? How is the section 3 (Purificaton of Al-Mg alloys) related to the previous sections?

Thank you for the amendment. The authors grately improved their manuscript, and the stracture become much better. Thus, I think this manuscript is ready for the publication in MRX.