CORROSION INVESTIGATION ON MATERIALS IN BLEACH MEDIA OF PAPER INDUSTRY

Abstract

The thesis starts with introducing the process of paper making in general and discussing the process conditions with a view to have an idea about the corrosivity of the liquors and possible candidate materials of construction. Emphasis has been given on the bleach plant as it is widely believed to be most corrosive section in a paper mill. In this endeavor, a review of the literature has been done and presented dealing with corrosion aspects and material performance in bleach plant and related liquors. The next chapter deals with the experimental aspects of the various laboratory and in-plant tests done as a part of present thesis work. Next three chapters discuss and analyse the work of the present thesis. The work presented in this thesis pertains to the corrosion behavior observed on commercial grades of mild steel and stainless steels in liquors of bleach media of paper industry. Besides this, attempt has been done to explore the mechanism of corrosion in the existing and future bleach plant conditions. Attempt has also been made to suggest possible materials of construction. The studies presented in this thesis involved laboratory and in-plant tests. The last chapter deals with the conclusion and recommendations on the work that needs to be done in future The summary of the thesis is presented now in the following paragraphs.